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Ventsim Visual™ User Guide

1. LOG VS_MainDecline_123 5 7 Tools Menu A selection of tools and settings to check modify and fine tune the model Displays a windows form that allows editing adding and deleting of all fans in the model fan database Up to one thousand 1000 fans and the associated fan curves may be entered Ventsim Visual User Manual Page 58 5 7 1 Levels 5 7 2 Stages 5 7 3 Spreadsheet into the fan database A display for each fan curve and data will be presented when a fan is selected from the display list For further information on entering and using fans see the Fan Section in this manual A list of elevation ranges on which airway data can be individually viewed This form allows editing or creating of a list of levels elevations between which airway data is located The level list can contain up to 1000 levels on which your model will be created Elevation data can be edited in any order as well as added at a later date Ventsim will sort the data from highest to lowest when next displayed To select which levels are displayed use the Data Display manager to select what levels to display Alternatively levels can also be independently set by using the mouse context pop up menu right mouse button on the screen to Se ect Levels To view ALL levels at any time simply use the Right Click pop up menu to select All Levels Levels can be sorted by clicking the column header for the desired item Opens the stage form wh
2. COX UO or Discharge pes D RB m2 temor The fan name is entered or MIA amO E Fan Curve Density 120km Chosen at the top from the pull ad Curve Estimation PE IA la wee purchased 2 4 95 e down menu To enter a new fan ETA select File gt New x i i Total Fan Total Absorbed Pressure Efficiency Y Power kW 3 At a minimum fan curve points for quantity and either fan static or total pressure must be entered for each fan Other curve information such as efficiency and power can also be entered to assist Ventsim Visual in estimating fan power and heat Fan total efficiency 8 D 50 Density is an optional parameter which will assume a S default value if not specified In 0 toe Leo Boe Ventsim Visual Advanced fan TT ee performance is adjusted for density changes in the mine Most manufactures supply fan curves at a standard density Figure 14 1 Fan Curve Entered into Ventsim Visual however different densities can be entered for the fan curve if required Pressure Pa Ventsim Visual User Manual Page 152 Diameter Fan speed Fan Reversal Curve Estimation Comments Point Table Diameter is also an optional parameter describing the exit diameter of a fan This may be the diameter of the fan casing or an evas if fitted Ensure the fan curve entered is for the specific fan configuration check with your fan manufacture for this Ad
3. Figure 5 16 Binding Tools Bind loose airway ends Ventsim Visual User Manual Page 62 5 7 6 Duplicates Defines the distance to join airway ends in a model which are close together but do not join Imported DXF file commonly have lines which don t exactly join due to editing or drawing methods used in the original file Airways which do not exactly join in Ventsim Visual will not flow air and will result in a No Exit Entry warning The search radius can be entered in the preset box For example a search radius of 4 will join any loose end airway end without another connection to any airways within 4m of the end Bind adjacent nodes Defines the distance to join adjacent connected nodes in a model which are close together but do not join This function is a little like simplify in that small airways between the joined nodes will be removed Warning Selecting this option with too greater distance can seriously distort the model Use with caution or not at all Bind airway ends to Junction Defines the distance to join airway ends to other airway mid sections It effectively splits and joins into the new airway Imported DXF files commonly have lines which cross the path of airway ends but do not have a joining node This function will create a joining node along the line Bind Crossed Airways at Intersection Defines the distance for joining airways that intersect or come close to intersecting but do not have
4. Copy Attributes Ctrl C Paste Attributes Ctrl V Copy Airways Paste Airways Name Find Next F3 Number Find All F4 Fans Flow Heat Source Pressure Contaminant Direction Errors Length Figure 5 9 Find Airway Data Selecting one of the options will find and highlight the airway searched for The option may be repeated for further branches by pressing the Find Next menu function the Find tool bar button or by pressing lt F3 gt on the keyboard HINT Pressing lt F3 gt will rapidly allow you to search through a model by repeatedly jumping to the next item To view more detail about the items being jumped to LEAVE THE EDIT BOX open The EDIT BOX will instantly update with detail about every airway that is jumped to Highlight or SelectHighlights or select all airways matching the previous find criteria To find A instances of All Fit All Show All Reset Display an airway for example to find all airways with the name shaft in the airway name or to find all fans click on an initial find type and then click on Find A All items with these parameters will Highlight and Flash For example if FIND was used to locate an airway with the name M52 Decline Select All would select ALL airways with this name in the airway name field The selected airway could then be edited or manipulated as a group 5 3 View Menu Fits all the display data into the view window CAUTION If display data is from t
5. Figure 16 4 Multiple Ducts Multiple Sizes If ducts require different sizes midway along the duct length then this can be altered by selecting the duct portion that requires a different size and then using the EDIT toolbar button to modify the duct size Because duct is automatically GROUPED when created to select only a section of the duct either use the SELECT fence function or ensure the CTRL key is held down while selected to override the GROUP functionality Figure 16 5 Partially changing the duct size Extending Duct To extend duct or create new tee sections and junctions it is normally recommend to remove then rebuild the entire duct with the new section Alternatively it is possible to build only the new section of duct with the duct builder tool however the connection section of the duct that join back to the airway will need to be manually removed with the DELETE button to ensure the duct does not dump the air back into the airway at the new join For example in the picture below a new auxiliary duct was created to extend into a new airway to the right of the main airway an duct The duct builder created the duct with a connection back into the main airway To ensure this duct is correctly joined the connection must be DELETED and the remaining end of the duct MOVED back to the main duct and Ventsim Visual User Manual Page 173 Figure 16 6 Extending an auxiliary duct 17 CONTAMINANT SIMULATION Stead
6. Figure 19 1 Inline Concentration represented by the green icon This method allows the user to inject a gas into an airway and observe the changes downstream It does not reset the concentration of gas passing the injection point and will therefore allow accumulation of gas concentration though the model Ventsim Visual User Manual Page 185 19 1 3 Linear Emission Method This method involves constructing a separate dummy airway to inject the gas into the model The injection dummy airway should connect to the surface to allow the injection to draw a quantity of gas separate from the model simulation The injected gas should then be set to the actual concentration eg 90 methane and a fixed flow amount set to specify the rate of injection into the model If very small fixed flow values need to be specified the unit accuracy for airflow may need to be increased in the Conversion Settings The model can then be simulated to show the results downstream To show the smaller concentrations of gas the colour legend display may need to be manually adjusted to show the full range of colours over a much smaller range Saved views Run Tools Window Help OAP eas y cH AI Dx DADODGO 1a O 2 236 0 000 9 000 I jected gas 500 Figure 19 2 Example of Injected Gas This method allows the user to specify a rate that gas may be emitting from an airway surface into the mine atmosphere for example coal seam
7. Simulation Update Frequency If simulation of sensors is required this can be done with steady state simulation or dynamically over time Steady state simulation can be done either manually by running a simulation from the normal toolbar automatically after every sensor update or at set time intervals Dynamic simulation is performed continuously and uses the most previous sensor values as base values for each location Dynamic simulation is computationally intensive and may slow computer response however it provides a more realistic spread of sensor data through a model LiveView data cannot be directly used in a Ventsim model until the individual sensors within the data source are identified and modified if required This is because some of the imported data may be invalid or unnecessary In addition some of the imported data may be missing basic attributes Ventsim LiveView keeps a copy of these modified sensors settings within the model so that future data imports are automatically correctly modified To define the sensors in the imported data click the Import and Modify Sensors button and then select the sensor you want to be able to access within the Ventsim model and transfer them into the Included Sensors list a Sensor Definitions oO included Sensors for Model Excluded Sensors from Data Sources ee 1 d SSIL2 SAFV1 Station SCH4 02 SSIL3 SAFV1 Station SCO_O02 SSIL4 SAFV1 Station SDBT_1
8. TAB Separated Value file a text file format used by Ventsim when saving uncompressed files This format can also be read into Spreadsheets Word Processors and databases Drawing Exchange Format An AutoCAD graphics file format that can be imported and exported by most CAD and Mining Software packages Ventsim can also import or export data in this format The start or end of an airway defined by an x y and z coordinate which gives its position in space in three dimensions Similar to friction power with the kilowatt value converted to a dollar cost per annum based on the default power cost 28 1 7 Friction factor or kAtkinson s friction factor describing the roughness or unevenness of a wall It directly factor 28 1 8 Friction loss 28 1 9 Friction power 28 1 10 Hardy Cross Method 28 1 11 Junction 28 1 12 Load Pressure 28 1 13 Network affects the resistance of an airway Friction factors are measured to a specific air density normally normalised to 1 2 kg m3 A component of pressure drop along an airway caused by the airway resistance Derived from the friction loss this estimates in kilowatts the amount of energy lost due to the resistance of an airway on the airflow The simulation method used by Ventsim Visual to perform the calculation of airflows in a model It uses an iterative estimation method that adjusts the airflows through a model until the estimation errors lie within acceptab
9. The increment at which Ventsim will advance the dynamic simulation Smaller increments result in more accurate simulation and greater sub cell formation however will take proportionally longer to simulate Warning because of the way sub cells work it is not recommended to use large increments as this will result in a loss of fidelity and accuracy in dynamic modelling If airflow travels the length of an airway faster than the time increment then the movement of cells through that airway is capped at the time increment resulting in a small inaccuracy in time calculated to travel through the airway Extensive occurrences of airways like this will cause simulation inaccuracies generally resulting in slower dispersion times than actual Chasm Consulting recommended increments of one second or less where possible and does not recommend increments more than 10 seconds for most conventional models The frequency per increment at which airflow simulation will occur if selected For example a frequency of 10 will perform an airflow simulation every 10 dynamic increments Airflow simulation is an intensive calculation and for larger models it is recommended to increase the frequency factor which will decrease the actual frequency of airflow simulation to reduce simulation time The frequency per increment at which data from the simulation will be collected for airways with a monitor in place For example a frequency of 10 will
10. e Seek a suitable Ventsim Visual training course to undertake advanced training in the product Ventsim Visual User Manual Page 169 16 AUXILLIARY VENTILATION AND DUCTS The auxiliary ventilation duct building function in Ventsim Visual provides an opportunity to model complex auxiliary duct arrangements in a mine model Auxiliary duct in mines is essential to ensure quality fresh air reaches areas of the mine without flow through ventilation which in most cases will be blind headings While auxiliary duct modelling is not a requirement for all models the modelling of auxiliary fans and duct may be important to ensure adequate ventilation is delivered to key area that the correct size duct and fan is used for a given length of duct and that the impact of heat humidity and furnes generated in auxiliary ventilated areas is correctly modelled on the remainder of the mine network 1 Duct Builder Diameter ie ez EES Leakage Porosity 250 Moderate High Leakage Intervals 50 m Offset Horizontal 0 0 m Offset Vertical 50 m 16 1 Introduction Simulation of contaminants through underground mines can be difficult to predict particularly if simulations are required to take into account the complex The vent duct builder box requires a number of values to be entered Diameter The diameter of the duct Friction Factor The friction factor of the duct This can be directly overridden with a custom value or additional friction fa
11. of the air in fact the dry bulb temperature is decreased and wet bulb temperature remains initially unchanged However the decreased ambient air temperature makes the cooler air more receptive to collecting heat from downstream rock surfaces resulting in increasing wet bulb temperatures As a result air quality and cooling power will more rapidly decrease and wet bulb temperature increase with the addition of moisture to the air 20 2 Application of Heat While Ventsim Visual analysis automatically considers heat from strata autocompression and fans the correct base assumptions or environmental factors must be first entered in the Ventsim model settings to establish the conditions in which the mine is being simulated See the Settings gt Simulation Environment section for further details All direct user specified heat into airways is entered via the EDIT box gt HEAT The most common user heat input source will be diesel heat or sensible dry heat however the user can also input latent water vapour heat refrigeratiion and oxidisation if applicable In addition the temperature of the air at a location can be specifically fixed to match actual Ventsim Visual User Manual Page 190 20 2 3 Sensible Heat 20 2 4 20 2 5 20 2 6 20 2 7 Diesel Heat Latent Heat Oxidisation Fan and Fixed Flow Heat data or to provide simulated feedback from Ventsim Visual on what is required to achieve such
12. D wm Y V G G a m 55 T Coniaminanis z Geram z coron E Figure 27 4 Draw horizontal airways from the ramp base 9 To create a shaft the easiest way is to CLICK the end of the airway while in the drawing ADD mode This will allow the coordinate or offset of the shaft to be entered For example to create a 200m high shaft simply enter 200 as the Z offset Ventsim Visual User Manual Page 243 Eat Coordinates vi et vm H om Saz Elevation Wector Offset Azimuth 00 H Dip Distance 200 0 z 200 0 H CIE Figure 27 5 Construct a shaft to the surface 10 To create additional sublevels simply draw new airways across from the ramp to the shaft ES Ventsim Visual II Beta TutorialLwsm ET E File Edit View Savedviews Run Connect Tools Settings Window Help Pedra a Emo ROS PRA Y PADUA 280 O OS 53 Fevourte Je ul T Contaminants eg oons IAA zeen 2065 37169 1007 Tree Compressible No oe Figure 27 6 Draw multiple levels for the mine 11 Edit the shaft airways and set them to a required size Label the airway and set the airflow as a fixed airflow to the desired amount of 150m3 s Ensure the airway has the Surface Connection checked Click on the top decline ramp airway and also ensure the Surface Connection is checked Click on Air Simulation to ensure everything works correctly Ventsim Visual User Manual Page 244 8
13. Ventsim Visual provides an Index number and a Unique number reference for each airway The Index number is referenced internally and during simulations by Ventsim Visual but may changed for each airway as airways are added or removed The Unique number will not change and should be used as a permanent reference number to each airway if other identifiers such as names are not used C Spreadsheet read on ly File Edit Select Index Air Loes Relative 3 Numb Number Quantity Densi Wall to Surf Absolute BarometricP E e Unique m3 s ensity Friction D gt Y P kPa kPa em kg m3 Pa Pa gt Pas 1377 12 702 o Im mm 3 323 ee 12 132 11789 98 9939 4 4 mn 2 Im o 101 101 z 5 0 1412 18 86 1 1009 101 8 a CH Data Selection Cu 7 7 8 359 Roo ao Ji Pressure 3 365 1 Attributes 10 10 14 Energy 11 41 fee n Lost EI Fan Fix Type 12 12 Z Friction Cost 13 113 E Friction Cost L f Friction Power D C Friction Power L 15 312 E Power Input F 1E Power Motor 16 330 i MTA Y 19 65 14 Identifiers 18 120 Contaminants 13 21 3 5 Measured 20 22 Figure 5 13 Spreadsheet view of model with selected data Filtering tools consist of a selection of airway utilities to help filter and correct complex disconnected or overlapping raw model data The tools can be run simultaneously as a group or individually The All Tools tab in the form allows simultaneous fi
14. against the name indicates it is currently being cHve_100 shown A indicates it is currently hidden A AA Appearance Colour Changes the colour of the items The second colour SE D shows the transparency effect on the colour Clicking the TE multi coloured box will colour the reference graphics ae object with a full spectrum of colours based on elevation Selection All tems o Show 1 Sowa Transparency Changes the transparency of the item ee Hide Hides the object from the screen view Meme Duplicates Delete Delete aL Show Shows the object in the screen view mm 1 Memory Used OK Merge Joins together two or more selected files from the Figure 5 6 Reference Graphics reference graphic list Manager Delete Removes the reference object from the file Duplicates Search all reference graphics for duplicate graphics and removes any duplicates to reduce memory requirements This function does not remove duplicates on different reference layers Memory Shows the current internal Ventsim memory reserved for storing reference graphics If this approaches 100 consider removing some reference graphics objects or alternatively if the computer has sufficient memory increase the Reference Graphics memory from the Settings gt Settings menu Title Note Allows the user to specify a unique file comment which appears in the top title bar This comment can help identify the date name and purpose of the model
15. evaporative effect which reduces dry bulb temperature and sensible heat and increases latent heat Removing moisture will produce the opposite effect Example of adding moisture to the air may include an evaporative cooling chamber or a dust suppression scrubber Directly removing moisture from air without cooling although technically possible is not a common mine process and this option in Ventsim Visual would only normally be used to condition air to a certain temperatures and humidity for simulation purposes Adds a combination of sensible and latent heat to the air to simulate a diesel heat source The result is generally a warmer moister air flow after application The ratio of sensible and latent heat added is controlled by the diesel to water ratio set in the heat settings menu Linear sources of heat and moisture are thermodynamic changes applied evenly over the length of an airway or airways The amount of heat per linear length generated by oxidising material in airway walls While oxidisation is not a significant factor in most mines exceptionally reactive sulphide or carbonaceous materials may have a significant effect where airflows are low or airway drives travel an exceptional length through high oxidisation rock Adds heat per unit length of the airway The value is intended to define heat sources which emit heat over a long length such as conveyor belts Setting a single equivalent point sensible heat to each
16. 7 3 12 Insert Node i gt Inserts a node or junction within an existing airway The airway is split into two 4Y airways as a result This node can then be moved or joined into by other airways Hint Drawing an airway into the middle of another airway will automatically create a new node or junction into the joined airway 7 3 13 Contaminant Ls Places a contaminant type within an airway A number of different contaminant types can be chosen Sr Ge e Y EN Contaminant Figure 7 10 Contaminant placing options Ventsim Visual User Manual Page 82 Left Mouse Click 7 3 14 Monitor Ee 7 3 15 Filter Ww 7 4 1 7 4 2 7 4 3 Airflow Simulation Heat Simulation ADVANCED Contaminant Simulation Contaminant Places a standard contaminant value defined in the Settings gt Contaminants in an airway Standard contaminants are considered unit less however different units can be specified in the settings All downstream simulation values will be related to the initial concentration of a contaminant in the airway s airflow Downstream contaminants are diluted proportionally to this value See the contaminant section for further detail Report Smoke Used in the contaminant source tracking routines this will place a smoke report within an airway After a contaminant tracking simulation all airways below this point will be considered as contaminated All airways upstream from this point will be consi
17. Bock Tue LayerPimay Sec ArTypes Fans Leakage Airways Profiles p Sensors geben iiinn Presets include Resistances Friction Factors Shock Factors and Equivalent Length Heat Refrigeration and Moisture Sources Layers Air Types Ventsim Visual User Manual Page 66 9 8 2 Units Decimals Combustible materials Fans limited to header information only Airway Types Airway Profiles And more Values entered into the preset spreadsheet will be made available for applying to airways in the EDIT box Updating existing values in the preset spreadsheet will automatically change all airways with that preset on the next simulation See the PRESETS section for further information Warning Be careful when removing existing settings from the preset spreadsheet Settings removed which already belong to an existing airway will force the airway to set the values permanently Sets the metric and imperial conversion units and factors used for Ventsim Visual as well as the number of decimal points to show on the display The conversion table displays the metric and corresponding imperial units for each type of data used in Ventsim Visual The table is saved with every model and can be individually modified for each model file The conversion settings can be inherited by other models or saved in a template file The imperial unit names and factors may be freely changed to suit the regio
18. Converting all imported centrelines to airways can be a problem if some model airways already exist and may be duplicated by this function Instead loading centrelines as a reference graphic without converting to airways can allow the user to check where extensions or changes to a mine model may be particular if some of the centrelines may overlap existing airways The reference lines will extend from existing ventilation airways showing where extensions to the mine ventilation model may be required The referenced centreline can then be selectively clicked or fenced to convert to airways using the Add gt Convert function A second option allows importing DWG or DXF files as references which places the graphics within the model but does not affect or interact with the model airways Examples may include mine surface terrain orebodies actual development solids etc This option allows the reference graphics to be used as a guide to building new airways or simply enhances the display with more information about the mine environment Any solids or wireframes that are present in the DXF will automatically be imported as a reference graphic as Ventsim Visual cannot build new airways from graphical solids only centrelines a Import Options E A OQUED3 E s ABL A ACCESO _D1_327 Vv Keep existing airways ALAMBRE_2009 e i i ASECTORC1 to Airw A ee CERRADO _HERMETICO Surfaces referenced m CHEVE_87 E CHVE 21
19. Drag Click Pan or move model about Show Popup Menu Click Centre model at mouse cursor Note the combined LEFT RIGHT mouse button can be used to simulate middle button Left Mouse Button View Mode Click Centre model at mouse cursor Double Click Edit airway at mouse cursor Hold and Drag Fence view and zoom into fenced aaa KEYBOARD COMMANDS Other Modes lt ESC gt Exit Function lt ESC gt x2 Exit Function and return to View Mode Move cursor in 3D vertical direction A lt BSPACE gt Undo last action Click e lt TAB gt Redo last action Activate Function lt F2 gt Plan Section View Toggle lt F3 gt Find airway Others See manual Appendix E for other commands Hold and Drag Fence Select airways inside lt SHIFT gt Ventsim Visual User Manual Page 27 4 4 The Edit Plane The Edit Plane is a horizontal plane at a set elevation By default any new airways are initially constructed on the edit plane The edit plane can be viewed by ensuring the grid function is turned on The plane will be crossed with grid coordinate lines If SA ftis selected the edit plane will be made semi transparent which will indicate where it intersects existing alrways he E Favourite y Levels y m T airflow y Quantity D m3 s S Lepe 70 Ga S DA Figure 4 2 The Edit Plane shown with the SHIFT key pressed To move an edit plane select a new point
20. EDIT 3 airways 200 0 File Select Airways Tools Airway Fans Heat Contaminant Gas Sensors Info Notes A Name Exhaust Shaft Unique 459 Entry Surface Ext Base 1 499 1 1 499 1 1 1 lt El Custom Surface E EDIT 3 airways 2000 A File Select Airways Tools Airway Fans Heat Contaminant Gas Sensors info Notes Fans 510 6 510 6 Index 106 Options FIP FSP e Fix Flow 15d m3ls Limit ow TT on Fix Press 00 Pa Fan Configuration 9 Paralle Seri Self Close 100 RPM E Close End O Round 3 ar E Show Data F Exclude E Fix Direction 2 Group m E Length F Gradient E Diffuser E Orifice 7 068583 mo 0 0 m2 Obstruct 768 m Down 250 ne 0 0 m Backfill 0 0 m3 s Quantity 0 0 Pa Friction P 0 0 ms Velocity D a Cas Jus Ces Jo ES Attributes O 0 0120 E Auto sema rr a Figure 27 7 Edit the airway to set the airway size Auto 0 0 Nil SSC Cae a 12 Click on the sublevel entries to the exhaust shaft Use the LIMIT FLOW function to set the 1 and 2 sublevel airflows to 50m3 s The lower sublevel will automatically simulate to 50m3 s to balance the 150m3 s total airflow into the shaft Clicking on the Edit Box info will show the required resistance to produce this airflow File Select Airways E y Airway Fans Heat Contaminant G Se
21. File Memo Allows users to write an extensive descriptor regarding the function or description of the current model This is saved with the file for future reference Page Setup Print Prints a graphic picture of the model in the View Window to an installed printer Print Preview Only printers with Windows supported graphics capabilities will be capable of printing the model As Ventsim Visual uses a perspective view no particular scale is applied to the image The image is sized to the maximum size of the page and orientation To reduce colour output the Ventsim screen colours can be changed under the Settings gt Settings gt Graphics gt Colours menu For detailed engineering accuracy output it is recommended to export the model to a DXF file for loading into a suitable CAD program for later output to a printer Previous File Quickly loads files recently loaded or saved Listing Ventsim Visual User Manual Page 43 5 1 19 Load Demonstration 5 1 20 License Manager Licenses Releasing a License Loads a generic model of a typical mine This is for demonstration purposes only and contains a number of simple mine examples to view Note that while these items can be modified they cannot be resaved in the same folder Opens the License Manager form gt Wentsim Visual Dic Licensing Manager File LICENSE No 500is activated License Type Full License License details found on the computer If no details
22. For detailed engineering studies it is important to consider plant design to establish overall economics and effectiveness for the proposed ventilation circuit In addition fouling and subsequent degradation of refrigeration plants should also be considered when allowing for contingency in sizing a refrigeration plant Ventsim Visual User Manual Page 195 Tier Standards Composition of Diesel Particulate Matter PM Atmospheric Standards 21 DIESEL PARTICULATE SIMULATION DPM Ventsim Visual Advanced Diesel Particulate Matter DPM concentrations are a relatively new concern for underground mining operations While prolonged exposure to high levels of diesel particulates has long been suspected as having potential to cause health problems only recently have mining regulators started imposing strict atmospheric exposure limits for underground mines Ventsim Visual Advanced provides tools to assist in predicting the distribution and concentration of diesel particulates through an underground mine 21 1 Application of DPM Simulation Ventsim Visual Advanced uses simplified homogenous mixing methods similar to contaminant simulation to simulate emissions from diesel equipment exhaust entering the airflow and being distributed downstream While real diesel output will always be variable because regulatory limits are normally based on an 8 hour time weight average TWA exposure for a person throughout a shift most of thes
23. It is used by the LIVEVIEW module to show external live data in a model Indicates the presence of shock loss in the airway The shock symbol representing swirling air is generally shown at the beginning where air enter the airway Ventsim Visual User Manual Page 268 31 1 1 31 1 2 31 1 3 Screen fails to display after coming out of sleep hybernation Resolution 31 APPENDIX D DISPLAY PROBLEMS Occasionally the user may find that the graphics displayed on the computer screen are not as intended The following section will step through some common problems and resolutions 31 1 Hardware Problems A large variety of graphics cards exists on the market today While each type of card should perform in the same way although some faster than others there are many different manufacturers and software drivers that may cause differences in expected performance Chasm Consulting tests a wide variety of different cards to ensure optimum performance where possible If an issue exists often updating the software driver from the card manufacture can help resolve issues Due to the low price of 3D graphics cards if the computer or graphics card Ze very old greater than 5 years it may be better to upgrade the computer or replace the graphics cards with a newer type The screen remains blank or shows corrupted data when resuming from screen savers or hybernation This is caused by the graphics card failing to
24. It will also automatically update after simulation with the latest airway results To view airway information for example leave the Edit Box selected on the Information Tab and airways throughout a model can be quickly analysed by clicking on the airway Likewise the Fan Tab could be left open and operating fan curves can be analysed quickly at different point in the model in the same way To modify data in an airway simply click on the cell you wish to modify and change the data The airway will automatically update when Apply or OK is pressed or when another airway is selected Multiple airways can be selected for simultaneous editing by fencing or selecting the airways while in Edit Mode and then clicking on any selected airway Any data within the Edit Box changed during editing multiple airways will be changed for all the selected airways For example if all selected airways require a width of 6m then after changing and applying the Width in the Edit Box the width and only the width of the selected airways would change All other attributes even if different between the selected airways remain unchanged Data that will be changed turns blue after modification To abandon these changes select Cance from the Edit Box before moving to another airway 3 8 Referenced Graphics Ventsim Visual permits the use of referencing external 3D graphics into the program such as wireframes surface terrains orebodies actual develop
25. LA A monitor is automatically placed on airways that have predefined dynamic events however to place monitors elsewhere in the model use the toolbar button shown above left Once selected simply click on an airway to add or remove a monitor Monitors can also be removed using the DELETE button Be aware that the amount of recorded data is limited and more monitors will consume greater amounts of recorded data space For lengthy simulation with many monitors the amount of monitor recording memory can be increased in the Settings Once placed on an airway a monitor will appears as follows 23 5 Establishing Simulation Parameters A wide range of settings can be adjusted for dynamic simulation including the time steps air simulation update frequency and screen graphics update frequency In addition variation parameters for changing the performance and behaviour of the fire can be Ventsim Visual User Manual Page 211 23 5 1 Resistance 23 5 2 Gases 23 5 3 Fuels changed Please ensure you are aware of the effects of these changes before experimenting A list of definitions and explanations is available in the Settings section Resistances can be added or changed during the simulation Any resistance set before a simulation starts and not defined by an Event will remain in place For example a resistance called a Mine Fire Door could be applied 20 minutes into a Ventfire simulation to simulate a scripted mine em
26. Models 22 3 Creating a Unique Version of an Airway for a Stage Whenever a variation is required of an existing airway for a particular stage for example an extra or different fan added a different airway size a different resistance or preset value a different heat source or event etc then a copy or duplicate of the airway must be made for use on that stage only There are several ways to do this Ensure the airways you wish to create a unique version of duplicate are set to show on the stage where the change is required Select and change to the required stage from the pull down menu on the main screen the airways should still show the SELECT and EDIT the airways with the EDIT box Jeje Use the stage Duplicate button to create a unique version of these airways This button will REMOVE the selected airways from the current stage and then create a duplicate of the airway that are set to only the current stage The edited airways can now be modified without affecting the same airways on another stage While still on the old stage select the airways you wish to appear on the new stage If the selected airways are already shared with the new stage EDIT the airways and deselect the new stage box so these airways will not show when switching to the new stage See EJ TI TT TT ttt tt lei While the airways are still selected choose EDIT gt COPY AIRWAYS menu switch to the new stage the airways should not be displa
27. Prevents the file from being opened or viewed When a security enabled file is loaded a dialog form will request a password If the password is not entered or is incorrect only the restricted security access option will be available Ventsim Visual User Manual Page 38 5 1 11 5 1 12 Save Picture Import Text Files Password Protectio The file is password protected Please enter the password mypasswordl CAUTION Passwords are case sensitive Ensure you can recall the password A lost password means the file will not be able to be opened or changed in the future Saves the current screen to a file location as an image file This file can be later loaded into documents or presentations from other software packages Imports external data into Ventsim Visual to build model model Ventsim can import data from TXT text files DXF drawing exchange format Autocad files DWG Autocad native format STR Surpac string files DM Datamine Files String or Wireframe Solid and VDP VnetPC files Imports model data from 7X7 format text format with fields delimited by a TAB character This format is widely available through most spreadsheets and can be read into word processors The standard format for a 7X7 file can be saved from Ventsim Visual under the save as command Most components such as fan database and colour settings can be excluded from a 7XT file leaving only the main file component if des
28. Sensors Info Notes Radon Y Activate Radon Radon Emission 9 26 Ba m2 s Radon Addition hs Bas Fix Radon Concentration 0 00 Bgl Fix Progeny Level 0 000 um 25 2 4 Simulating Radon Radon simulation can be performed as a Steady State simulation by eee 0 simulating directly from the EDIT form or from the Contaminant Simulation sub option Contaminant DPM Radon can also be simulated using the Dynamic simulation options 9 Radon although because of the simulation technique results may slightly vary Reverse Find Sou antaminant o PREMIUM version Radon simulation results will show Radon and progeny levels distributed through the mine as colours and data As will most other Ventsim units the different Radon results can be specified in the colour and data menus under the separate Radon data category Clear Contaminants Radon units and decimal accuracy can be altered in the TOOLS gt UNITS main menu In addition the standard year work hours for calculating dosage can be adjusted in the RADON section of the TOOLS gt SETTINGS gt SIMULATION menu Ventsim Visual User Manual Page 233 Option 1 Quick Select Option 2 Selected Airways 26 FINANCIAL OPTIMISATION Advanced Ventsim Visual provides many useful tools to analyse and develop strategies to save money While the total ventilation cost for most mines Is significant in many cases much of the cost of ventilat
29. Y Import Surfaces CHVE 91 Y Keep existing references CHVE_10 F CHVE_12SUP CHVE_14 CHVE_18 Wireframed only Al l Coordinates O Metric Swap Axis CHVE_2005 Imperial E Convert 2D CHVE_34 CHVE_49A X Offset 0 CHVE_49B Y Offset 0 CHVE_53A Z Offset 0 CHVE_53B Scale CHVE_57 F CHVE_57A CHVE_60 CHVE_62 F CHVE_70 CHVE_76 CHVE_77 CHVE_78A F CHVE_78B CHVE_78C CHVE_78D CHVE_79_B_MODIFICADA F CHVE_79 C F CHVE_79_D_AUX o als ue m N A al A O BOO o m a Al Gi Bal oui Sea Use DXF Colours Import All Layers 7 Split Layer Names Y Filter Splines A de PA Figure 5 4 Import Option form showing DXF import options Import reference files can be merged with an existing model for example a mine addition and new airways built with DXF centre lines can be set with default attributes airway sizes etc before importing Attributes can easily be changed later within the program HINT File imports support drag n drop Simple grab the file from a windows folder or directory and drop it on the Ventsim Visual screen More than one file can be imported at a time by using the SHIFT or CTRL key to select and load the files Ventsim Visual User Manual Page 40 Import Options Import Centrelines Merge Data Import as reference only Surfaces referenced Import Solids Merge References Wi
30. across resistance Resolution 32 2 12 operating fan restricted by resistance Resolution 32 2 13 fix being over restricted Resolution 32 2 14 unresolved pressure or flow Resolution 32 2 15 fan static P curve invalid check fan Resolution 32 2 16 fan total P curve invalid check fan Resolution simulaton settings Ventsim will not attempt to solve heat balance and will simply assume the air temperature becomes the same as the virgin rock temperature Increase airflow through airway or increase tolerance of massflow setting in the Settings menu to ignore airways with low flow Pressure building up unacceptably over a high resistance airway or a fan or fixed flow running into a high resistance airway This error may occasionally show up when simulating Ventsim Classic 3 9 models with Ventsim Visual Investigate and remove the source of the high pressure fan or fix or remove the high resistance causing the buildup in pressure Unlike Ventsim Classic 3 which ignore this error this situation is unacceptable to Ventsim Visual as it adversely affects air densities and heat buildup and in nearly all cases is a result of user input error Pressure above 15000 Pa are generaly used as a trigger for this error A resistance has been placed in the same airway as a fan and the fan is being unreasonably restricted This is a common practise in Ventsim Classic 3 9 models to stop airflow through a fan In Ventsim Visua
31. and also the large shaft design but with a lower pressure fan The ventilation design connecting the shafts in all three options is similar For this example three 3 stages can be used to represent the three different options Because the horizontal mine design connecting the shafts is similar in all cases then the airways for the horizontal mine design can be shared and set to belong to all three stages The Option 1 large shaft is also used in Option 3 however in this case a different fan is intended to be used for this shaft airway Therefore the large shaft IS NOT common between Stage 1 and 3 and can only be set to belong to Stage 1 Stage 3 will require an identical duplicate of this large shaft airway but with a different fan low pressure that is only set to belong to Stage 3 The two smaller shafts are utilised by Stage 2 and 3 and therefore must be set to belong to each of these stages providing the same fans are used for these shafts in both cases A user wishes to design two totally different ventilation models with very few if any shared airways between stages For this example each stage can be a totally new set of airways When changing to different stages new airways will by default only belong to the stage they are constructed on unless extended from other multi stage airways The user is welcome to construct new independent non shared ventilation models on each stage If a common skeleton of airway
32. assumed 50 100 ug m3 The Ventsim user decides to convert the PM value to an Elemental Carbon value of 0 08g kW hr and enters this value in the Heat Presets Next the user must decide the average diesel power output of the engine during the shift DO NOT ENTER THE MAXIMUM diesel engine power as no typical diesel equipment will run at full engine power for the entire shift and using this value will over predict DPM Ventsim Visual User Manual Page 197 concentrations The best method is to measure actual fuel consumption for the shift and use the Heat Assistant in Ventsim to calculate average engine power output In most cases trucks and loaders will not exceed 50 of their rated power and auxiliary equipment and light vehicles will be much less File Edit Resistance Friction Shock Heat Layer Primary Layer Sec AirTypes Fans Sensible Latent Refrig ae Linear Linear Oxidising Name Heat Heat Moisture Heat Heat kW kW kW ged g sim Win Conveyor Heat 4000 Crusher Heat H o Pump Station 4 Transfer Conveyor 1 Loader 16m3 50 rati 4 Truck 50T 50 rating 4 Figure 21 1 Diesel Equipment with DPM emissions in Preset Values The user has five loaders with rated diesel engine power of 250kW each After observing fuel usage for the shift the user specifies the machine put out an average of 125kW of diesel power
33. calculated and used Guides in setting Shock Value are available in most quality ventilation texts 9 5 Fans Displays a form allowing fan and fixed airflows and pressures to be applied to an airway If a fan is present a fan curve graph and duty will be displayed after simulation showing fan performance in a simulated model airway If no fan is present in the airway being edited a blank window will be displayed Ventsim Visual User Manual Page 99 28 EDIT 1 airways 18 0 m gt E File Select Airways Tools 9 806028 ae OC W Auto CONT status Fan ON O cose 15 Fixed Flow 24 7 ms T Restrict Only Pressure 0 0 Pa Fan Y Stope Exhaust Fan v 1 100 3 Counter rotate Fan Pressure Curve Total e 1x Fans Air density 1 23 kg m3 rpm 100 Duty FTP 671 3 Pa Quantity 22 1 m3 s 1 4 me Efficiency 74 4 Power 19 9 kW shat 21 0 kW electrical Cost 18 356 Pressure Efficiency Power Pressure Pa 0 3 5 a 10 13 16 18 21 23 26 Quantity m3 s Air Simulation APPLY OK Cancel Figure 9 8 Edit Box Fan Information Fan Settings Sets fans fixed flows or fixed pressures within the airway This setting allows the user to include a pressure or flow to move air around a model Without at least one airway within a model containing a fan or a fix flow or pressure there will be no airflow within a model unless natural ventilation pressures are present ON Tu
34. information to import into Ventsim The data from sensors may be sent to Ventsim in a number of different ways including Microsoft SQL servers MYSQL servers Microsoft Access Microsoft Excel CSV and TXT text file Please note that Microsoft Access and Excel are proprietary Microsoft licenses formats and require drivers to be installed in Windows to access the file types If you have Microsoft Office 2010 or later installed your computer may have these drivers already If not you can install the drivers from the free Microsoft download Microsoft Access Database Engine 2010 Redistributable from http www microsoft com en au download details aspx id 13255 Please ensure the correct 32 or 64 bit version of the drivers are installed if running Ventsim 32 bit install the 32 bit version if running Ventsim 64 bit install the 64 bit version Warning If Microsoft Office has already been installed the version of the Microsoft connectivity drivers will correspond with the Office version installed 32 or 64 bit It is currently common for end users to install 32 bit versions of Microsoft Office on 64 bit Windows computers In this case only the 32 bit installation of Ventsim will work with these drivers This issue only relates to Excel and Access type files Ventsim Visual User Manual Page 221 To access LiveView click on the CONNECT gt LIVEVIEW gt SETTINGS in Ventsim Live VIEW lol File Edit Data Connections E
35. mixtures which can be defined in the PRESET table and will automatically apply the gases to the airway when set Gases which are not fixed will be automatically adjusted to ensure the total volume concentration of all combined gases remain at 100 The adjustment is done proportionally so gases which are not fixed for example Nitrogen at 79 will be adjusted proportionally more than lower concentration gases for example Oxygen as 21 Pressing the simulation directly from the Edit form or the Contamination Gas Simulation sub button on the toolbar will run a Steady State simulation Alternatively gas simulation can be performed dynamically using the Dynamic Simulation gt Gas button 60N0 0 Contaminant Find Source Clear Contaminants Reverse Contaminant Figure 19 3 Run the gas simulation option To display the results the text or colour display may need to be changed to select the type of gas to be reviewed The colour legend values may also need to be manually changed to show the full range of colours for the desired concentrations Ventsim Visual User Manual Page 187 Neal DG EB T o E vlenses gt D cas vi e T eas zo de Display 5 eax Figure 19 4 Change the text and colour to show gas concentrations To clear the results of a gas simulation and reset the model back to a standard atmospheric gas composition use the Clear Contaminants options 19 3 Density Based Simul
36. simply uncheck the fix check box When a fixed pressure is simulated the program will calculate the required airflow and power to produce the fixed pressure The results of fixing a pressure will be displayed in the INFO box Selects a fan for the airway The upper pull down menu allows a fan to be selected from the fan database Fans are sorted in the order established in the Preset form Adjacent to the fan name is the number of fans to be included in the model and below this is the configuration of the fans parallel or series Fans installed in series will increase available fan installation pressure according to the number of fans available while fans installed in parallel will increase available airflow Selecting the Ej will remove the fan from the airway Selecting EDIT will jump straight to the fan curve database edit screen Displays the fan curve pressure type used for the simulation TOTAL is a Fan Total Pressure FTP curve while STATIC is a Fan Static Pressure FSP curve This is selected automatically if one or the other curve is unavailable Ventsim will preferentially use an TOTAL PRESSURE fan curve if available except for auxiliary fans connected to ventilation duct which will use STATIC curves If a combination of FAN STATIC and FAN TOTAL curves are used in a model then with the exception of auxiliary fans a mixed pressure simulation solution method is used which ignores exhaust velocity pressure from a mine It is r
37. 6494 3 kW Summation of heat minus refrigeration Moisture Point Sources Moisture Linear Sources Moisture Input as Latent Moisture Airway Surfaces Model condensation 4404 ml sec Number of point moisture sources such as conveyor dust suppression spray Number of liner moisture sources man made such as decline dust sprays Summary of moisture added from latent heat sources such as diesel engines and latent point sources Summary of moisture evaporated from rock strata Summary of moisture condensed as water normally in upcast exhaust shafts It can also indicate formation of fog in a mine MOISTURE EXHAUSTED 4403 ml sec Total moisture exhausted from mine Ventsim Visual User Manual Page 56 How much Heat Audit Error is too much Graphs Input heat below surface 6454 5 kW Check to make sure heat exhausted from mine is accounted for from summation of underground heat sources Elevation adjustment 29 5 kW Adjustment due to inlet exhaust elevation differences auto compression Differential inlet to outlet 6469 9 kW Different between inlet from surface heat and exhaust to surface heat Potential heat imbalance 14 1 kW 0 2 Error between the underground inputs and the surface recordings Potential temp 0 01 C degrees Potential error in temperature as a result imbalance Figure 5 11 Example of Summary Output with Description Heat Audit errors occur due to simulation approx
38. 9 in it can use fan total pressures FTP fan static pressures FSP or a mixture of both Using FSP curves will ignore the fan velocity pressure FVP portion contribution to model pressures but will also ignore any system exit velocity losses to surface throughout the model Using FTP curves will include the FVP portion but will include system exit velocity pressure losses as part of the model system total pressure Ventsim Visual User Manual Page 155 Estimate Tools Menu The case for Fan Static Pressure Simulation It is technically correct for simulations to use fan total pressure FTP curves for fan installations Fan total pressure however is not always converted into useful ventilation energy due to outlet losses from fan installation configurations Traditionally Ventsim Classic 3 9 has encouraged users to utilise fan static pressure FSP curves for modelling Using FSP curves excludes the velocity dynamic component of fan pressure curve which is therefore assumed not to contribute to the overall system pressures in a model simulation To partly offset the lack of fan velocity pressure inclusion the system exit velocity pressures the velocity pressure loss to the model from air exiting from shafts or other exhaust airways are also not included by Ventsim Classic 3 9 in calculating overall system pressure While these two factors partially cancel each other out using Staticcurves for underground fans is likely to give a sl
39. AAA AA AA AAA AA AA 34 5 1 3 Le 35 5 1 4 OVER 35 5 1 5 SIV CNG onto ne EE 35 5 1 6 Masters 35 5 1 7 AN 36 5 1 8 A A A ed on Lae el 37 5 1 9 ee EEN 37 SO ANO TOOLS iS IS AS a 38 E E A 9 E EE 39 ILI ECHTEN 39 SA DONE EEN 42 541 14 EE 42 STIS Meel ege 43 5116 Fil Memo ME 43 5 1 17 Page Setup Print Print Preview 43 DLAs dl A A e EE 43 SAT LOGO Demons Tano A Ao 44 22O License Mand GET EEN 44 Page 7 E PE EE 45 5 2 GEI D WEE 46 5 2 1 o E E E E 46 5 2 2 PEOS EE E A AE AA 46 5 2 3 COPY ONG PASTO AIS AAA AAA AA ASS ASA A AA A AA 46 5 2 4 Clone and APOY ATTIDUTE S ana A AAA AA 46 5 2 5 NCW AIL WOU ee 47 5 2 6 FING EING NOE FING Anda 47 5 2 7 FIORE AE ORSAI aia 48 5 3 IS TON 48 5 3 1 EH 48 5 3 2 SHOW Als AAA AAA Ar Na 48 53 3 reeL 48 5 3 4 QUICK EENS 49 5 3 5 CODY tO CUPO Usina ii oa 49 5 3 6 EE 49 5 3 7 Copy to cubbodra HEEN 49 5 3 8 EST Ae Okc NOU erna E HOT RNR N ERE SPIN CR Monty Ror rr VR NERT TER Tree reer eR rT RMT Aree TEr 49 5 3 9 SOU EGC CONTE dos 50 5 310 SHOW ALP Elevations A AR AAA A ii 50 SL PSROW AU QVCIS ANA AS 50 5312 e Ee wi sebansvace wanseaesbancnecvapaoudeseancvnes nanioissesusseesunnaaes 50 S3 THIS AS AAA A AS A A E 50 5 4 SAVED WIE WIV EN tee 50 5 4 1 SOVE VIC o US 50 5 4 2 EE 50 5 4 3 SVC VIEWS ee 50 5 5 DAOIN NYA CIR 52 So TANI IOWS TAL aa 52 5 5 2 Thermo dynamics ADVANCED s0scssosccesosssesosesesosesesosesesosssesoscsesosssesscsesussesoses
40. Axis Swaps the Easting and Northing X and Y coordinates of all airways in the model This may be useful where the coordinate system in Ventsim Visual does not match the directions used on the Mine Plan Grid Where the direction of the coordinates needs to be reversed use the Settings gt COORDINATES settings to change direction of the axis coordinates Rotate Coordinates A utility which rotates all if none are selected or just the selected airways by a number of degree around the point of focus The point of focus is always at the centre of the screen It can be set by middle clicking the mouse button on a point or by entering the centre coordinates in the View gt Set Edit Centre option Mirror Axis Allows all airway coordinates to be mirrored around the centre location of the screen Note that the centre location must be accurately set before this function is used Reverse Coordinates Changes the sign of airway coordinates from positive to negative or visa versa Not that this is similar to mirroring coordinates around a zero centre Scale Coordinates A utility which scales all airway or reference coordinates by an input factor This effectively reduces or increases the size of the model without changing the airway size An airway length will not be changed if it has been fixed Warning this function should only be used to scale schematic ventilation model with predefined fixed airway lengths Scale a model without fixed length will
41. Classic was released in 1994 and enjoyed many years as a simple but popular ventilation software program to simulate airflows and pressures in mine Despite limitations such as incompressible flows and lack of heat simulation many hundreds of mines adopted Ventsim Classic for use Ventsim Classic was improved to version 3 9 however all development on this program was stopped in 2007 after which time Ventsim Visual was developed Ventsim Visual was completely rewritten from the ground up It is a substantially different program than Ventsim Classic 3 9 and takes a new approach to ventilation display and simulation This section will give you a brief overview of the major changes if you are familiar with Ventsim Classic 3 9 and may also assist if you are familiar with other ventilation software packages In most cases Ventsim Classic models can be imported directly into Ventsim Visual Every graphical aspect of the program has a necessary function to help make ventilation models easier to understand and reduce the opportunity for error The 3D graphics accurately represent the true size shape and location of underground airways The colouring represents many different types of data for example temperature or pressure The animated arrows show both the speed and direction of airflow By removing or reducing the need to comb through excessive amount of textual data ventilation models can be analysed and validated much faster than
42. Conditions of air entering a mine All air intakes into the mine are assigned the default surface temperatures The temperatures and Surface Barometric Pressure are used to calculate the surface air density HINT In rare cases a mine may have multiple intake airways with a range of elevations so great that different temperatures may be present at each intake As the Surface Barometric pressure is defined for a single Surface Elevation Barometric Pressures will be correctly recalculated for differing intake elevations however temperatures may need to be manually corrected Temperatures can be adjusted by place a heat or cooling source at the inlet of intakes to produce differing temperatures Surface Pressure The Barometric Air Pressure at the Surface Elevation The surface barometric pressure is Barometric important as Ventsim Visual calculates mine air densities from the surface barometric pressure and wet and dry bulb temperatures Surface Elevation The elevation or reduced level where a specified point in the mine exits the surface All other surface related settings such as surface temperatures pressures and rock temperatures are assumed to be at this elevation If this value is set to zero 0 Ventsim will search and use the highest point in the model Surface Rock Temp The temperature of virgin rock at the Surface Elevation All virgin rock temperatures underground are calculated from this base elevation by using the Geothe
43. Further information is available from the Live VIEW section of this manual Ventlog is a software program designed to record and collate underground surveyed ventilation data The Ventlog database can be interfaced with Ventsim to provide the ability to show actual Ventlog data results overlayed with Ventsim simulation results This provides a useful tool to compare actual and simulated values when trying to validate a model Allows the user to specify a Ventlog file VLG to connect to Loads the Ventlog station data into the Ventsim model The Ventlog data will be overlayed over the corresponding airways in the model The date of the data import can be specified in the connect option Exports stations created in the Ventsim model to a Ventlog database This establishes stations in Ventlog complete with correct coordinates and eliminates the need to separately create the stations in the Ventlog program When the Ventlog software is next used the stations can be viewed and edited and new data can be entered against the stations To create a Ventlog station directly in Ventsim EDIT an airways then use the NOTE section of the tab to create a Ventlog Station The name of the station can be changed to anything however the LOG must remain unchanged as this represents a code used by Ventsim to export the station File Select Airways Tools Airway Fans Heat Contaminant Gas Dy Sensors Info Notes Airway Notes Add ventiog Station Cl
44. SRAD1 SAFV1 Station SWBT_O2 SRAD2 SAFV2 Station SAFV_N2 5H251 SAFV2 Station SCH4_N2 5H252 SAFV2 Station SCO_N2 5H253 SAFV2 Station SDBT N2 SSMK1 SAFV2 Station SWBT_N2 SSMK2 AFV3 SSMK3 AFV3 SSMK4 H AF 3 E SWBT1 St SWBT1 S SWBT1 St SWBT1 St X EJ e Clear All Remove Edit OK Cancel The included list will contain GREEN values if the data source connections still contain these sensor names If the data source no longer contains these sensors names or is temporarily offline or unavailable then the included sensor names will be shown in RED If sensor names in RED are included in a Ventsim airway the LiveView display will not update the values Once the sensors are included in the list they are available to assign to individual airways However if they are missing important information such as the type of value or alarm levels they may be of limited use Therefore it is important to assign attributes to the sensors to help Ventsim understand more about the sensor Assigning Attributes to Sensors To EDIT a sensor and assign attributes select the sensor or sensors from the list and click EDIT Normally a sensor must at least be defined with a type eg velocity methane gas Ventsim Visual User Manual Page 227 etc If these items are not defined in the Imported Data then they must be manually set using the Sensor Editor Other attributes such as alarm levels metric imperial units and whether the sensor sh
45. Sky example presented below the data colour display is set to Head Cost L friction pressure cost per metre The colour sliders are adjusted to show airways costing greater than 2 per metre per year Airways below this are made transparent to clarify the display The data clearly shows in particular two air shafts with extremely high costs per metre one in particular at over 600 per metre per year as well as a horizontal connecting airway costing nearly 300 per metre If the mine life was substantial it would not be hard to justify enlarging or installing a second shaft system to reduce overall ventilation costs In this case increasing shaft size from 3 0m to 3 5m reduced per metre annual ventilation costs from 600 per metre to 250 per metre Over 10 years this would result in a saving of 400 000 for this relatively short airway Ventsim Visual User Manual Page 238 K i fa Ventsim Visual I Beta blue_sky vsm Example Metal Mine with Problems gt D File Edit View Savedviews Run Connect Tools Settings Window Help PiGloc S 68 ARNO Aroma HA A PADUA os Energy v Friction Power l y kwm Be T Airflow v Quantity ech e el Elo el Coords 1998 8E 1100 9N 58Z Airsimulation successful Compressible Yes NVP Yes airways 527 Figure 26 4 High Cost Airways coloured to show clearly 26 3 Ventilation on Demand An increasingly popular method of redu
46. Ventsim Visual has been written to make the process of ventilation model analysis as easy to use as possible Both versions utilise sophisticated 3D graphics driven by a fully graphical mouse driven interface Ventsim Visual is compatible with Microsoft Windows XP VISTA WINDOWS 7 and WINDOWS 8 The software can also be run on Apple Mac Computers with suitable graphics hardware running Microsoft Windows under dual boot or emulation Ventsim Visual automatically installs as a 32 bit or 64 bit version The 64 bit version has the ability to utilise additional computer memory and therefore much larger models can be used Recommend Page 18 maximum model sizes are 30 000 airways for the 32 bit version and up to 100 000 airways for 64 bit versions Increased amounts of DXF reference data can also to set to be displayed in the 64 bit version 2 2 Computer Hardware Requirements Ventsim relies heavily on 3D graphics hardware to present detailed smooth graphics While most computers these days have this functionality built in older computer may not and may struggle to produce acceptable performance Even modern computers particularly laptops may have substandard graphics hardware for displaying 3D graphics and performance may not be as good as expected The following guide is recommended for computers Minimum Configuration e Intel based AMD or Intel processor 1 Ghz e Windows XP Vista or Windows 7 8 e Memory 2G or RAM Har
47. Ventsim Visual User Manual Page 257 29 APPENDIX B SUMMARY OF DATA TYPES 29 1 Summary of the major data types Available from the data selection menus in the menu bar Note that additional data and data subsets are available in the spreadsheet view 29 1 1 Air types Airtyoe The type of category of air in the model Originally designed for specifying fresh exhaust and undetermined air within a model Ventsim Visual allows custom catagories for air types set from within the Edit menu When specified in the Display Manager airtype will show different colours for different air types 29 1 2 Airflow Quantity The volume flow rate of air through an airway Velocity The average speed of airflow through an airway across the cross sectional area Density The average wet air density along an airway For vertical shafts this is the air density mid way along the shaft Mass Flow The dry mass flow of air through an airway This is a function of volume flow and air density Note that this will not necessarily be equal to the quantity x wet density value because the mass flow does not consider the moisture component that is included in the density value 29 1 3 Pressure Pressure Boost The increase in pressure provide to a model system by an external source such as a fan or fixed flow Pressure BoostStatic The fan static pressure equivalent of the pressure boost Pressure Regulator Load The pressure or force against an airway re
48. a decline consisting of 10 airway segments will normally show data for every segment To only show one text data for all the segments ensure only one airway is set to Show Data and the activated the LIMITED gt text display To force an airway segment to show data use the EDIT box and click Always Show Data Show Unlimited Shows all airway data regardless of whether the Show Data option is set in the Edit box 6 1 9 Text Ka Controls how much text information is displayed on the screen Display ALL Displays text information for data values node names airway names and error messages Hide ALL Hides all text information Data Ainways Nodes Text data airway names or node names can be individually turned on or off by selecting Grid Log Values them from the view menu 6 1 1 Transparency By default all data which is non active for example levels or layers which are turned off R data which is outside of the Display Manager or zero flows if set are shown as a Eh transparency with the transparency amount set in the Display Manager To specifically hide some items for example layers which are not visible but still show transparencies for other items for example Zero Flows or Coloured Data data types can be individually set to show transparency or be hidden Data coloured data which is outside of the selection range in the Display Manager and is selected to be hidden can be made transparent or removed f
49. a significant re write of the software not only for the graphics engine which was now required to handle significantly increased levels of graphical complexity but also for the user interface which needed redesigning to help the user manage the additional windows and settings To enable users to display different types of data and colour in each window it is necessary for additional controls and toolbar buttons to be available in each window for example drop down lists to allow selection of colours and text To ensure users can control the complexity of the controls on the screen additional functionality was added to enable toolbars to be hidden or moved In addition some of the most commonly used menu items such as edit locking and airway interceptions camera snapshots perspective views and the show all function have been moved to the main toolbar However Ventsim Visual 3 0 is much more than a graphical upgrade The software contains a host of new features to enable ventilation models to be developed with more detail and sophistication than ever before The new staging feature allows models to include many variations and changes all within a single file A complete life of mine ventilation model is now possible showing all different stages of ventilation design In addition models can contain multiple options within the same file Dynamic simulation routines have also been re written allowing users to simulate the time ba
50. absorption will decrease Conversely if the fire heat reduces and air temperatures fall below the heated rock surface this rock skin layer can rapidly release heat back into the airway airflow during simulation Use Gas Density for Air Simulation Uses the relative density of different gas compositions to apply natural ventilation pressures to airflow during simulation Gas compositions may be set using the gas options in the EDIT box or from VentFIRE simulations 12 4 6 Heat ADVANCED Adjusts settings which directly influence how the heat simulation performs Ventsim Visual User Manual Page 142 Diesel Efficiency Heat Divisions Min Max Multi Heat Iterations ES Ventsim Visual oir gs Diesel Particle Emmisions 0 100 OkKvV br Heat Divisions Maximum 20 Heat Divisions Minimum 2 Heat erations 100 Mass Flow Limit 0 10 kg s Maximum Heat Input 100 000 0 KW Muti Heat terations 1 Refrigeration Ob AA Temperature Accuracy Temperature Limit Use Matural Ventilation Pressures Water To Diesel Ratio Simulation Heat Figure 12 6 Simulation Heat Settings The efficiency at which diesel engine mechanical output is derived from the total heat of combustion of the fuel source Ventsim uses this value to convert diesel engine power sources into heat during simulation Ventsim assumes by default all diesel engine output power AND wasted inefficiencies enter the airflow as latent and sensible heat The heat calculated from a d
51. addition if a common fundamental change on one model is made for example the decline size is changed then as none of the stages share airways then the same change would have to be manually made for all the decline airways on all the stages A smarter way is to ensure common airways are shared This creates a smaller model file requires less memory and ensures changes to common airways are reflected in all stages automatically e The FILE gt LOAD DEMONSTRATION gt METAL MINE example shows a progressive stage design with four 4 different stages e A useful technique in creating such a model is to start with a full final ventilation design with ALL airways belonging to ALL stages e Then work backward towards the initial stages of a ventilation design and progressively remove the airways that do not belong to particular stages Work Backwards For example assuming that by STAGE 4 all airways have been established then while Technique displaying STAGE 3 which currently has all airways included e Select and EDIT the airways that do not belong to STAGE 3 by removing the selection of the STAGE 3 box in the EDIT form e If the same airways do not belong to STAGE 2 and 1 then clear these boxes as well Press OK these airways will disappear from the STAGE 3 design e Do the same for STAGE 2 and STAGE 1 Finally create specific changes for each stage to create viable workable designs using the copying techniques described in the
52. airflow exhaust 1040 2 m3 s Total airflow exhausting from the mine to the surface Because of air density changes due to heat an elevation this may not match the intake value on models with compressible flow Mine resistance 0 00164 Ns2 m8 Cumulative resistance of moving the total airflow through the mine This includes the resistance of ventilation ducts and recirculated air so caution should be taken in adopting this value for primary airflows Total mass flow 1260 kg s Total mass of air flowing through the mine Note that this is dry mass flow which excludes moisture content Ventsim Visual User Manual Page 54 1772 2 kW AIR loss Power Total theoretical power required to move air through all airways Total installed electrical power required to move airflow INPUT Power 3609 2 kW pow me NN Model Efficiency 49 1 Ratio of theoretical friction loss to installed power Model efficiency will decrease as more fans are required to boost airflow through mine Placing fans in series i e boosting accumulates fan efficiency losses at each stage of the fan Total fan installation in model Total number of fans in model Fans turned off Fans operating at their maximum pressure MODEL FAN SUMMARY Fan Installations Fan Sites Switched Off Fan Sites Stalled Fan Sites Low Pressure Fans operating at a pressure beneath the lowest fan curve pressure but still above zero Fan Sites Negated F
53. airway will produce the same heat result Ventsim Visual User Manual Page 104 Moisture Linear Adds or removes moisture per unit length of airway Similar to the moisture point addition this less commonly used function may be of value is simulating a long length of airway water addition such as decline dust suppression sprays Hint How much moisture as being added to your airways from sprays To practically assess the amount take a wet and dry bulb temperature above and below the sprays and use the Ventsim Visual Heat and Moisture Calculator to estimate the change in moisture content Fixed Data Air Temp 40 34 0 Diesel Emission 9 100 oi thr Advance Rate 0 0 mimth Diesel Engine Adds a combination of sensible and latent heat to the air over the length of the airway A linear diesel source is sometimes used in preference to a number of individual diesel point sources to represent a fleet of diesel equipment travelling along a selected route of airways To establish this type of collective heat addition the average diesel motor output of the equipment fleet needs to be summed and divided by the length of airway the fleet would travel The resulting heat per length value can then be applied at a linear source to all the airways the equipment fleet would follow This method is considered to provide a slightly more accurate way to apply a moving heat source but has the disadvantage of being harder to visualise as independent machi
54. applied and the next airway data will be displayed Multiple airways can be selected and simultaneously edited from the Edit Box Note that not all Edit Functions are available for multiple editing and some function may be hidden To utilise multiple airway editing simply Se ecf the required airways before the Edit Box is opened Only attributes that are changed and therefore highlighted in BLUE are applied to the selected airway s The Airway Tab Page defines most of the airway attributes associated with airflow and pressure simulation as well as basic airway information such as names and airway coordinates Ventsim Visual User Manual Page 92 9 4 1 9 4 2 Airway Names Coordinates and Stages Airway Size 28 EDIT 1 airways 237 5 m li ESO File Select Airways Tools 3 Fans Heat Contaminant Gas e 1 Sg Surface A Close End 7 Show Data 7 Exclude m C Fix Direction 7 Group ged E Length 237 5 E Gradient 167981 E Diffuser 45 Orifice 0 0 ont Primary Layer All Levels e m2 m2 mis Pa mis ora TH rar sys 0 09605 Auto e Ns2Im8 0 0050 1 1 RaiseBored Airway kqim3 0 Auto Figure 9 2 Airway Edit Box Form Sets the airway and node names airway coordinates and airway stages To set new names or coordinates simply type the information into the relevant text boxes Names are optional and are not required for the simulation The stages which the airways belong to can be
55. are present then the license is not activated and will run in VIEWER mode License Version Full Advanced License Start 21 Nov 2011 License End License Days Remaining Maintenance Support Expiry Number Status Computer ope NEW Stewal CHASM2 Active Stewart CHASM AGG Betis erain MERE Status display panel for sites with multiple licenses Licenses can be automatically selected double clicked and activated from this list License Activation Information Company Chasm Consulting Registration information must Site or User Name Office be entered EXACTLY as shown License Code 16 digits 92 52 5 on license detai Is Site License Number 500 Show Digits Contact Email E e de Test www ventsim com web connection The site license issued number Each license number has a Ey unique license code Figure 5 7 Automatic License Activation and Release Ventsim Visual licenses are floating licenses which can only be used on one computer at a time They can be activated for use on one computer and then if required re eased and used on another computer within the terms of the license agreement License certificates are stored on the Ventsim server and prevent simultaneous installation of the same license on more than one computer As part of the digital licensing agreement the license collects the computer name and user name of the computer that Ventsim Visual is currently activated on This sys
56. be errors File Select Airways Tools Airway Fans Heat Contaminant Gas Dynamic Sensors Info Notes Fans Options Fan Configuration r kk H 3 Paralle Fix Flow 10q mass Series a a F 1 E ee re Figure 15 6 Placing a fixed flow in an airway Once a fan or fixed flow is placed simulating the model will align all connected airways in the direction of airflow Airways that are not aligned or show no airflow may be dead ends or may not be connected properly to the model Airways without flow should be closely examined for corrected airway ends If there are NO ENTRY EXIT warnings these will normally be caused by airways with dead ends These can be selected and EDIT directly from the Warnings Box and then closed using the CLOSE END function in the EDIT box If other warnings are present where airways are not connected correctly run the BINDING tools again with a larger search radius or just manually use the MOVE button to move the airways ends together The above steps should sort out most of the erroneous airways Connected airways that show NO ENTRY OR EXIT errors may be because all of the airways do not travel in the same direction Ventsim automatically establishes this direction where airflow is present however this cannot be done for dead ends The warnings can be fixed by either CLOSE END the airways with warning or by manually reversing individual airways with the REVERSE but
57. button can be clicked to enter the preset spreadsheet and create names for defined wetness fraction values Age or Year Entry The age in years since the start of the airway was mined in decimal years for example 4 5 or the calendar year of mining in decimal format for example 2006 5 would represent end of June in the year 2006 Age or Year Exit The age in years since the end of the airway was mined Airway ages can be a mixture of calendar years and age in years Ventsim Visual determines which age type has been entered by the number of digits in the date field Four 4 digits indicate a calendar year age Where calendar year ages are entered airway ages are calculated from the Current Calendar Year age set in the Settings Menu VRTemp Entry Exit Manually sets the Virgin Rock Temperature at the start and end of an airway This function is unlikely to be used often It forces the heat simulation to use preset rock temperature values instead of calculating the rock temperature from the geothermal gradient This function may be of assistance if the rock does not conform to the geothermal gradient parameters for example mining through backfill or the rock temperature is being modified by other factors such as local geothermal sources or reactions Note that the values normally reported in these cells are calculated from the simulation and will change with depth and time To FIX the values to permanent temperatures simply overwrite t
58. colour range Ventsim Visual User Manual Page 21 3 7 1 3 7 2 3 7 3 The Edit Box The Information Tab Modifying Data This creates a rich but potentially confusing interface To simplify things Ventsim Visual uses both a Display Manager Control form to assist in rapid analysing and changing of on screen data and colour This control can be utilised via the view menu or from the toolbar It is important to note that colours can be displayed independently of the text data which is shown on screen for example pressures can be showed at a colour range while text data could show air flows Colour ranges can be adjusted nthe Display Manager with the slider bars or by manually entering new ranges 3 6 Coordinates Ventsim has switched to a more conventional Eastern Northing Elevation coordinate approach The relative directions on screen of these coordinates can be changed in the Settings menu Ventsim Visual allows decimal point coordinates to be used allowing more accurate placement of airways While this will have little effect on ventilation flows it removes the saw tooth effect often seen in the Ventsim Classic 3 9 integer coordinate display 3 7 Editing and Information The Edit Box now acts as a powerful editing and information tool for airways in a model The Edit Box may be left open permanently and will update with information from the airway clicked on during viewing editing and adding modes
59. densities and a fan manufacturers will need to know the required density to the fan curve can be adjusted for the local condition accordingly For Ventsim Visual Standard incompressible air is assumed and the air density remains constant and is specified in the Settings menu For Ventsim Visual Advanced this value varies throughout the mine and may be significantly different from the surface or standard density value The Air Density is specified in the airway or in the Fan or Fix summary page in the Edit Box Fixed pressures work in much the same way as fixed airflows but instead forces Ventsim Visual to calculate a resulting airflow to match the input pressures As with fixed flows fixed pressures consume power and produce heat which again is summarised in the Edit Box information summary or from the Model Summary menu item When calculating power and heat for a fixed pressure the default fan fix efficiency from the Settings Menu is used More information on fixed airflow and pressure is available from the Edit Box functions 15 5 Simulating Airflow in a Model A critical part of developing new models is ensuring air can move through new airways Ventsim Visual User Manual Page 165 Place a Fan or a Fixed flow in the model to SIMULATE and start air moving through the model This does not need to be accurate at this stage it is simply a way to determine the connected paths where ventilation can flow and where there may
60. e em em ell Figure 5 15 The simplify dialog box Maximum Joined Angle The Max Angle option specifies the maximum angle between two airways being considered for merging For example if the original model contains a number of airways that form a curve and Max Angle is set to 20 degrees Simplify will keep on merging airways until the airways being considered have directions changed by 20 degrees or more Ventsim Visual User Manual Page 61 Maximum Joined Length The Max Length option restricts simplification to airways less than the specified length For example if set to 30m only airways with lengths of less than 30m will be considered for merging and simplifying In general the higher the values of the Max Angle and Max Length settings the more aggressively Ventsim Visual will simplify and combine airways Use combined lengths Ensure the new length of a combined airway is fixed to remain exactly the same as the original combined lengths even if the original airways formed a curve If not set the new lengths will be recalculated as the true length of the new straight line In most cases the difference is minor and it is recommended to leave this option unchecked Ensure no resistance Ensures that airways with a preset resistance such as a bulk headed airway are not presets filtered simplified and merged with other airways Ensure airways Check to see if airways that are considered for merging and simplifying are only joined
61. exit airway or surface connection sssccsesseesssesssesssseesssessssessssessssessssessssesstsesatsesssessateseaeenss 271 BAS MORENO EE 271 321 4 dirway stopping redundant a 271 321 5 JANE enn WIEN ANOIMAS AA 271 S246 FXreg res EE EE EE Ee 271 321 7 gt TeMPerature balancing EE 272 E IStQHEO ON Uan a caia 272 321 9 JOW PIeSSUIE TON Saa 272 ALIO MEU COTO esca 272 32 1 1 Water suspension velocfy En 272 32 2 e 272 32 2 1 airway attempted tO TevVerSE En 272 3222 PAHOMGIOUS EE 272 32 DUNCAN 273 3224 EE FlOW CONO DE INCA aaa 273 A TOENG OVNI EE 273 3226 Operating JON DIOCKEO ii AA eweiial 273 3227 NEIER 273 32 2 8 temperature outside allowable range En 273 32 2 9 heat estimation error encOuntered en 273 32 2 10 temp estimation near rock surface En 273 322 11 OVERDFESSUFC OCTOSS TESISCONCE AENA AAA RA 274 32 2 12 operating fan restricted by restetonce En 274 EUA E E d ee o EE 274 32214 URVESOIVER Pressure OO Wi a iii 274 32 2 15 fan static P curve invalid check FO ia 274 32 2 16 fan total P curve invalid COEN a A da 274 22d Meshing CNO eh 275 APPENDIX F SHORTCUT Ee 276 APPENDIX TABLE OF FIGURES ocu 277 1 Ventsim Visual Version 3 Whats new Ventsim Visual 3 marks a significant change to previous versions of Ventsim Visual Ventsim Version 3 0 introduces a multi window interface allowing users to simultaneously show different parts of the ventilation model in different windows This required
62. form gea e Recommends an airway size based on the current simulated or fixed flow Note that this is a recommendation based exclusively on the current flow airway attributes and cost data entered into the Settings If these values have not been established yet do not use this feature to estimate the most efficient airway size Also note that if the airway size is accepted this may actually change simulation results and other adjustments elsewhere in the model to fans or regulators may be required to return the airway to original flow rates Warning do not use this feature unless the required airflow rate has currently been simulated or fixed in the airway and the default COST settings have been set in the Settings gt Settings gt Costing Removes wall contacts from the airflow to simulate open airways or stope panels that are joined to each other but do not have for example side wall connecting the airways The air friction and heat transfer factors on these excluded walls are removed from the simulation Select the check box representing the walls that do not exist Number of Airways The number of parallel airways defined by the single airway This allows multiple airways in parallel to be represented and simulated by a single displayed airway The width of the airway Ventsim Visual User Manual Page 94 9 4 3 Hisigtit Area Obstruction Backfill Length Quantity Friction P Velocity Airway Op
63. function can be activated from the File Import menu STEP 1 Create and Import a DXF file into Ventsim Visual This method relies on passing line or string graphics mer oston ENEE i A fo data from a CAD or Mine Planning package to Ventsim 7 Ze 101 j i Se 103 Visual The data may simply be the centre lines of NAAA a e E onvert to Airway Solids Surveyed mine floors or mine designs To allow SES E Ventsim Visual to efficiently use this data without mpor surtaces Jro D D 8 D D D V Keep existing references excessive post import editing the following criteria ay e should be considered Ee 15 O Metric Swap Axis Imperial Convert 2D e Only import the minimum data required on Excessive detail or headings which do not form Z offset 0 Scale 1 0004 part of the ventilation model should not be imported if possible In many cases is may ros be quicker and more accurate to construct a PR 255 7 Defaut Colour skeleton ventilation model consisting of 7 Use DXF Colours interconnected lines within the Mine Planning ES or CAD package before import into Ventsim T Fiter Spines Visual The skeleton lines should simply trace over existing mine workings or designs Rotate 0 0 kengen keem e Try to ensure the lines join into each other so Ventsim Visual knows they are junctions through which air can flow Lines that simply cross each other without a junction or which terminate close to each other but
64. gas The emission is entered in litres per second per metre l sec m along the airway and gradually replaces the atmosphere in the airway over time Note that the method used is replacement which is not strictly accurate as in reality the gas adds to the atmospheric volume causing a change in ventilation flows In most cases however the ventilation flow change is minute and can be ignored If the emission rate is significant and is likely to independently cause a change in airflows and perhaps push gas into other airways then the more cumbersome injection method should be considered instead VI ET EH PBITDI A 4 4000 97 200 0 04 T nati ai BS Ventsim Visual User Manual Page 186 19 2 1 Placing Gas Sources 19 2 2 Simulating Results 19 2 Simulating Gas Sources File Select Airways Tools Airway Fans Heat Contaminant Gas Dynamic Sensors Info Notes Gas Mixture Coal Seam Gas vv Linear Emmision 1 24 litres sec metre Gas Simulation O EE EOI 1 airways 2678 SS The EDIT form has a facility to fix the concentration of gas compositions in any airway injected or in line in the ventilation model All gas concentrations should be entered as a volume based concentration value not mass based and then FIXED to instruct the simulation to use the specified amount If gas mixtures are to be commonly used throughout a model it is recommended to establish PRESET gas
65. if dimensions are the same they are exactly the same size Ensure wall types are the Similar to dimensions only airways with similar wall friction factor types are joined same Selected airways only Only simplify selected airways and ignore all others HINT Short irregular airway segments are best simplified with high joined angle settings 45 degrees or smaller joined length settings lt 20m Long smooth airway segments are best simplified with low joined angle settings lt 20 degrees and high joined length settings gt 50m Note that airways can be individually selected for simplification 5 7 5 Binding Binding connects disconnected airways ends or intersections Many imported DXF files do not have correctly connected centre lines or ends This function will search for unconnected ends or crossed airways and join them together if they are close enough Airways must always be correctly joined to allow air to flow Warning These functions are intended for preliminary clean up of new models not for existing balanced models It can permanently change the characteristics of your model and may delete some preset items or values Ensure only the required airways are first SELECTED before binding or simplification au Filter All Airways Al Tools Simplify Binding Duplicates Convert to 3D Binding Parameters m V Bind loose airway ends Bind adjacent nodes Bind crossed airways at intersection o Bind
66. is chosen the effect of diffuser size on surface exhaust shafts can be examined Simply click on the surface airway and select diffuser and place a size large than the fan or airway Alternatively you can construct a short enlarged surface connection airway which will produce a similar effect to including an evas option in an airway In Summary In most cases if fan exit shock losses are modelled are modelled correctly the Fan Total Pressure FTP method is the best option to use 14 3 Fan Database Menu Items The tools menu contains a number of functions to assist in estimating fan static or total fan curves as if either one is unavailable as well as fan total shaft efficiency and fan absorbed power if either one is unavailable This may be required if only a Fan Static Pressure FSP curve is available and you wish to simulate the model using a Fan Total Pressure FTP curve Ventsim Visual will use the outlet diameter of the fan to calculate the velocity exit pressure of the fan and thereby calculate the missing static or total pressure curve To estimate absorbed power Ventsim Visual will calculate theoretical power using total pressure and airflow Note that none of these estimation methods take into account shock losses resistance and compression factors which will slightly affect calculated pressure and Ventsim Visual User Manual Page 156 powers It therefore should be used as a guide only and is no substi
67. is that changing ventilation conditions and contaminants can be tracked through the mine at specific times and in most cases the Ventsim model can be dynamically changed for example different levels of contaminants can be changed or the model airflows resistances or fans can be altered to see the effect on contaminant flow 18 1 View Dynamic Simulation Results Dynamic simulation employs two methods of observing results The simulation will dynamically show the on screen results as the simulation progresses Ensure the text and colours are showing the required simulation data type during the simulation to see the results Alternatively a monitor can be placed in an airway to observe and record the simulation changes historically CH To view the results contained in a monitor simply click the VIEW button on the monitor to view a graph of results Ventsim Visual User Manual Page 178 E a a o o E a 5 E a E g o PIERA s d bi ai d d vk d ay ai amp N aD d a S Ae SEPEEEEEEEEEECEEE EOE OF Time Second Figure 18 1 Example of Blasting Gases at a monitor location 18 2 Contaminant Dynamic Performs a dynamic contaminant simulation based on the position of contaminant source placed in the model The simulation will run a continuous time based simulation showing the track and concentration of fumes The simulation can be paused at any time and the colour or type of data can be changed during
68. mining in either decimal years eg 2005 5 end June 2005 or by a fixed relative age eg 4 5 4 5 years or 4 years and 6 months The thermal diffusivity of rock within an airway The virgin rock temperature the rock temperature before the airway excavation and airflow may have cooled the surrounding rock mass Unused at this time in Ventsim Visual version 3 0 The gas contamination levels of a wide range if gases During simulation Ventsim volumetrically balances non fixed gases to ensure 100 total volumetric concentration Note that RADON gas at this time is NOT simulated for radon daughter decay Ventsim Visual User Manual Page 263 30 APPENDIX C ICON PICTURE GUIDE 30 1 Airway Icons A number of icons are used in Ventsim Visual to represent various airway attributes The icons are displayed on top of the airway solid or wireframe and indicate the presence of a specific item Multiple attributes in an airway represented by icons are shown side by side Icons can be turned off or on from the Display Manager or from the right mouse button context menu Icons can be MOVED along airways by selecting the MOVE function from the toolbar and dragging the icons along the airway with the left mouse button Icons can be COPIED to other airways by selecting the COPY button function from the toolbar and dragging the icon to a new airway 30 2 Customized Icons Fan resistance and heat icons can be customized in Ventsim
69. normally standardised Adjustment to sea level air density and will be adjusted for different air densities Ventsim Visual will internally adjust friction factors during simulation according to the local air density If this box s not checked the friction factor entered is assumed to be derived from a standard air density as specified in the Settings Menu for Simulation Air which is normally 1 2kg m3 unless set otherwise In most cases friction factors are likely to have been derived from preset values at standard air densities and this option should remain unchecked Ventsim Visual User Manual Page 98 Shock Loss Factors If the box schecked Ventsim Visual will assume an adjustment has already been included and will not attempt to adjust the friction factor further Examples of this may be if the friction has been measured along a specific airway underground at a density similar to that simulated by the program Sets a shock loss factor for the airway Shock losses can be set as an equivalent length or as a shock loss factor X The method used is defined in the Settings Only one method can be used for all airways Ensure shock values are consistent with the method chosen in the settings throughout the model Shock values can be manually entered in the text box set to a Preset Value or set to an Automatic value from the pull down menu at the right To change or establish new preset values press the Shock button and en
70. not join will not carry airflow and may result in a no exit entry error in Ventsim which will need to be corrected in Ventsim When importing data the lines can be converted to airways during the import process by selected the option Convert to airways or selectively after importing using the DRAW gt CONVERT button to click or fence which lines are to be converted The second option has the advantage of overlaying the updated DXF files with new development over the existing Ventsim airways and selectively choosing where to update the Ventsim model Hint To efficiently add DXF data to Ventsim Visual keep a layer object or file within your Mine Planning or CAD package dedicated to Ventsim Visual data As new airways or designs become available simply export the additions as separate DXF files and import them into Ventsim Visual to add to the existing model Warning Three dimensional solids such as survey mine solids will import into Ventsim Visual but cannot directly be converted to airway They can however be used as a guide to manually draw and construct new airways in the model Ventsim Visual User Manual Page 161 ES Ventsim Visual D Beta Tas Terrain dxf lay Sa anni da File Edit View SavedViews Run Connect Tools Settings Window Help MASSA ATA SETE cl DI y PONRS OD of ED Favourite y Levels x m ers T Airflow y Quantity
71. of contaminants and potential sources of the contaminant Indicates a fresh air report has been placed within the airway A Contaminant Find simulation will use this report to indicate pathways of fresh air through the mine Animated Indicates the presence of a contaminant in the airway A contaminant simulation will predict the path and concentration of the contaminant downstream A sourcing simulation will predict the paths and relative amounts of sourced air travelling to the airway Animated Ventsim Visual User Manual Page 266 Indicates the presence of a gas mixture in the airway A gas simulation will predict the path and concentration of the gases downstream 30 2 10 Thermo dynamic Heat or Moisture Source Indicates the presence of a positive heat or moisture source in the airway A Thermodynamic simulation will mix the quantities and distribute the changes downstream A grey colour indicates the preset heat or moisture has been turned off in the Edit box 30 2 11 Thermo dynamic Cooling or Drying Source Indicates the presence of a negative heat source cooling or refrigeration or a moisture removing source in the airway A Thermodynamic simulation will mix the quantities and distribute the changes downstream A grey colour indicates the preset heat or moisture has been turned off in the Edit box 30 2 12 Airway Notes Indicates text notes have been made for the airway Text notes can be viewed
72. of focus by centering on an airway or use the Shift Mouse Scrol combination to move the edit plane elevation The coordinates in the status bar at the Bottom Left corner will always show the elevation of the edit plane Hint The Edit Plane will also temporarily move automatically to the level of an airway being drawn from another airway Additionally the edit plane and point of focus can be moved manually by the Set Edit Plane function in the View menu Figure 4 3 True Vertical Line showing top and bottom airways lining up Ventsim Visual User Manual Page 28 4 5 1 4 5 2 The True Vertical Guide Drawing Airways Figure 4 4 True Vertical Guide Line helps guide a shaft vertically into the airway below 4 5 Drawing in the Third Dimension Drawing in three dimensions can be a challenge as the view is being displayed on a two dimensional screen monitor Ventsim Visual alleviates this problem by only drawing on the horizontal plane except when the shift key is pressed or the screen is orientated to a vertical cross section orientation 3D perspective views do not necessarily show a vertical object as pointing straight up As objects move further left and right of the point of focus they lean over away from the centre of the view To assist the user as to which direction is truly up while creating or editing airways a true vertical line is displayed while drawing moving or copying If the object being drawn aligns
73. of sensible latent or diesel heat input The amount of sigma heat present in airflow multiplied by the mass flow of the air through the airway The difference in these values should be equivalent to the total heat addition to the airway The moisture content of the air relative to the total saturation potential of the air at the current temperature and pressure conditions The volume flow of moisture condensation from airflow due to environmental conditions changes which result in air temperatures or pressures falling below the saturation point of air This normally results from a refrigeration source chilling air below the dew point temperature or a reduction in barometric pressure from air travelling up a shaft for example reducing air moisture carrying capacity Displays the results of heat simulation at the entry and exit of the airway The data displayed is Read Only and is for information purposes only Most of the values displayed are self explanatory More detailed airway information is available under the Information Tab The calculated elevation of the start left and end right nodes of the airway The calculated wet bulb temperature at either end of the airway The calculated dry bulb temperature at either end of the airway The calculated relative humidity and the moisture content of the air The calculated virgin rock temperature at either end of the airway This value is calculated from the geothermal gradient t
74. on an airway All S E airways of the same size as the initial selection will be same Contaminant Type selected Once selected the airways can be edited deleted Figure 7 7 Multi Selection Options move etc 7 3 6 Delete Deletes an airway or airways from a model Ventsim Visual User Manual Page 80 Left Mouse Click Delete the airway Left clicking the mouse on top of an airway will delete the airway beneath the mouse cursor If multiple airways have been selected it will delete all selected airways Left Mouse Drag Selects the airways within the fence box being drawn Selected airways can then be deleted by clicking on any of the selected airways Ye 7 3 7 Deletion Options ale TI ER Delete airways Delete airways outside fence Delete references Delete references outside fence Figure 7 8 Deletion options Presents a number of deletion options Delete airways outside fence will delete all airways not inside the fenced area This can be useful to remove errant airways which may be located a long way away from the main model Delete references removes DXF graphics within the fence area Delete references outside fence remove DXF graphics not within the fenced area 7 3 8 Block O Blocks or unblocks an airway with the highest resistance available as defined in the Settings menu This will restrict nearly all airflow through the airway Warning Ensure that fans or fixed flows are not present in blocked
75. operating duty point is shown at the intersection of the horizontal and vertical lines The efficiency curve and the airflow volume intersection point define the efficiency the fan is operating at The efficiency value is used to calculate the estimated fan shaft power If fan shaft power is entered in the database directly a fan power curve will be shown and the program will derive shaft power from this curve instead If a power curve has been entered for the fan the power curve and the airflow volume intersection point will define the shaft or absorbed fan blade power the fan s are operating at Ventsim will preferentially use this curve to calculate power if present If the power curve has not been entered for the fan the efficiency curve will be used to calculate power If this is not present the default efficiency in the settings menu will be used 9 6 Heat Tab Advanced Version The heat Tab Page controls most of the airway attributes associated with heat and moisture simulation File Select Airways Tools Heating ES Nil Airway Fans Heat Contaminant Gas Dynamic Sensors Info Notes e Fj i Heating Cooling Rock Type Reset Loader R2900 Y gneiss y Source Point Source Rock Type Heat Sensible 0 0 KW Heat Sensible 0 0 kw Conductivity 2 90 Wim Heat Latent 0 0 kw Diffusivity 1 290 m2 s 11 Heat Latent 0 0 kw Refrigeration 0 0 kw Specific Heat 300 0 J kgC S we Refrigeration 0 0 kw Moisture D misec Roc
76. or recirculated air in each airway The definition of recirculation is the passage of airflow or a portion of airflow through the same point in a mine more than once Ventsim Visual uses a custom algorithm to track the paths and recirculated portion of every airflow throughout a mine and report where airflow may recirculate To prevent trivial reporting of recirculating air such as minor leakage of air through a high resistance stopping a default tolerance of 1m3 s recirculation is used These limits can be changed in the Settings form Recirculating airflows are shown Figure 5 10 Example showing a ventilation fa as a portion or of air which has di Ai recirculated through the same airway Note that this is not necessarily the total amount of recirculated air travel through a location only the portion of air travelling through the current location and returning to the same location Air in some cases may have recirculated upstream in a different part of the mine and will not be reported as recirculated in downstream headings that do no recirculate To view the downstream effect of recirculated air click on the Recirculated Stream data or colour option instead of the Recirculation option Ventsim Visual User Manual Page 53 5 5 7 Financial Provides a number of methods for optimising airway sizes including defining set airway Simulation sizes and costs for consideration or by defined mining costs as variable and fixe
77. particulates at different times however it provides a useful baseline to examine the effects of changing ventilation circuits and flow in a mine For more information see Diesel Particulate Simulation Simulates the time based spread of contaminants gases heat and DPM contaminants Time based dynamic simulation show the results of a simulation on the screen at increasing time increments that can be paused and resumed Only one of these dynamic simulation parameters can be simulated at a time although the PREMIUM VentFIRE module can simulate multiple parameters simultaneously To record a history of time base simulation results monitors can be placed at defined locations to record changes to ventilation flow For more information see Dynamic Simulation VentFIRE as the name suggests allows for complex simulation of fire heat and contaminants In addition it allows for simultaneous dynamic simulation of multiple ventilation parameters such as airflow gases contaminants DPM s and heat VentFIRE allows models to be automatically modified during simulation to enable scenarios such as altering fans opening or closing doors or moving machines to be modelled dynamically over time For more information see the VentFIRE Simulation section Examines a model for paths which may File Edit View SavedViews Run Tools Window Help recirculate airflow in a mine and reports 3442890 gen Zem DA OOOO HG Di H LBE i the
78. partiulcarly if one fan is operating outside of its specified fan curve Resolution Recommmend removing a fan or ensuring an alternative airway path is available to help bleed pressure between fans 32 1 6 Fix requires A limit flow option has been place in an airway to slow down airflows however the pressure unrestricted airflow has been placed directly in series with another fan The pressure imbalance between the fan curves may cause difficulty in resolve the model partiulcarly if one fan is operating outside of its specified fan curve Ventsim Visual User Manual Page 271 32 1 7 32 1 8 32 1 9 32 1 10 Resolution temperature balancing issue Resolution stalled fan Resolution low pressure fan Resolution negated fan Resolution 32 1 1 Water 32 2 1 32 2 2 suspension velocity Resolution airway attempted to reverse Resolution Anomalous pressures Resolution Recommmend removing a fan or ensuring an alternative airway path is available to help bleed pressure between fans Thermodynamic simulation is having difficulty resolving temperature balance between two airways This may happen at extremes of temperature or pressure Investigate what is causing high low temperatures eg high heat or refirgeration loads coupled with low airflows Resolve problem if possible The Settings menu can be set to ignore this program but this is generally not recommend
79. paths included to simulate vent duct leakage In some mines airways may connect to other parts of a mine which are not simulated or included in the model The airflow to or from these other parts must be included into the local model To include airflows to areas not simulated or included in the current model simply run a single airway off the main model assign a Connect to Surface attribute under the Edit Form and then enter either a fixed flow or fixed pressure to simulate airflow to or from the area Ensure the direction of the airway is correct 15 6 Utilizing Layers Layers are a way to individually layer or identify and view parts of a model separately from other parts of the model Some examples may include a stope system an orepass or ventilation raise system a workshop area or any other collection of airways Note that there is no requirement for the user to utilise viewing layers They are only present to allow easier manipulation and viewing of a model The Metal Mine example in the Ventsim gt File gt Demonstration menu shows an example of layers Ventsim Visual User Manual Page 167 15 6 1 Primary Layers Layers work by allowing the user to overlay multiple layers of airways or information on a screen By doing this unnecessary detail can be turned off so only airways of interest are viewed Layers may be made active or displayed using the Display Manager Layers names can be changed from the Edit Box b
80. per second surface coverage A default of 0 1mm is suggested Ventsim Visual User Manual Page 141 Residual Heat Rock Absorptivity Age Rock Boundary Heat Flux 12 4 5 Gas Limit Wetness fraction settings for rock influences evaporative cooling of airflow flowing past a rock surface In the event of a fire the rate of evaporation can easily exceed the rate at which water will replenish the rock surface Therefore it is important to limit the flow of water otherwise the hot air from a fire will be artificially cooled at a rate much greater than would be possible in a real life scenario Maintains a minimum flow of heat from the fire source even if insufficient oxygen causes combustion rates to fall below this level Heat from a fire does not immediately cease if the combustion is reduced or ceased by lack of oxygen Significant amounts of heat may be stored within the combustible structure mass and may continue to be released even without direct combustion To ensure the simulation continues to receive at least some heat during periods of low oxygen this value can be set at a portion of the normal full combustible heat level The modified radial heat transfer age coefficient Ventsim uses for fire simulation Normal steady state heat simulation requires a rock exposure age in years to modify the exposed rock mass to a temperature closer to the long term air temperature For fire simulation the rock mass surrounding the immed
81. potential energy to another process This reduces the effective diesel heat input into the model Ventsim Visual User Manual Page 149 13 1 5 Electric Similar to the diesel engine calculator this allows the user to estimate the heat emitting from an electric motor based on its duty cycle and conversion of work into useful energy Motor Power Motor Efficiency Litilisation 3 Potential Energy Conversion Estimated Hectrical Heat Source Average Motor Heat Output Calculate Figure 13 5 Electric motor heat estimation 13 1 6 Water Flow The water flow calculator estimates the amount of heat entered or removed from a model from water flow source It can be used for both hot water and chilled water calculations Water Temp Inlet Water Temp Outlet Water flow Estimated Heating Cooling Sensible Heat 816 5 kW Calculate Copy to Clipboard Figure 13 6 Heat Assistant Screen The Water tab may be useful for estimating e How much cooling power a cooling tower or spray chamber is producing from a refrigeration water source Ventsim Visual will calculate how much cooling is being generated from the flow and temperature change of the water into the airflow e How much heat a geothermal water source may be putting into a model To calculate the heat input simply input the average water temperature entering the mine from a rock fissures for example and enter the average water temperature and flow exiting the min
82. previous section e Or if a ventilation design such as a duct is required just for one stage ensure that when the duct is created it is edited to only belong to the stage it is required for Work Forwards Technique Alternatively start with the initial model design on Stage 1 for example Once this design 22 4 3 Other Uses for Staging is working select ALL the airways and set the airways to show on Stage 2 e Switch to Stage 2 and continue creating further airways either drawing or by using DXF centre lines New airways will be automatically set to belong only to the currently displayed stage unless an airway is drawn connected from an existing airway in this case it will adopt the stage settings of the connected airway e If any airways from Stage 1 do not carry over to Stage 2 then SELECT and EDIT to remove the airways from the Stage 2 design If any airways from Stage 1 need to be modified for Stage 2 then select these airways and use the EDIT BOX gt Auto Create option described in the previous section to ensure that a unique copy is made for the new stage e Once Stage 2 design is complete select ALL of the airways on Stage 2 and set them to also belong to Stage 3 Switch the display to Stage 3 and then repeat the previous step to continue working on successive stages Even if models designs remain largely the same staging can be used to run different heat gas or contaminant scenarios In this case each st
83. program Ventsim Visual provides a full toolbox of tightly integrated utilities to analyse ventilation flows heat contaminants and financial aspects of mine ventilation Building on the success and experience of fifteen years of Ventsim implementation at over 800 sites Ventsim Visual goes a generation further in its approach to ventilation simulation and analysis and sets a new standard in ventilation software design and implementation 2 1 About Ventsim Visual Ventilation has been a primary concern in underground mines for hundreds of years but until the introduction of computerized model analysis in the last 40 years the planning and modelling of ventilation was largely a black art relying on experience guesswork and extensive calculations Page 17 Even when computer ventilation software allowed simulations of large models of underground airways the process of entering and interpreting results still remained a job for experts in the field Ventsim Visual aims to make ventilation simulation and design accessible to any mine engineer or ventilation officer even those without substantial ventilation experience Ventsim Visual Standard provides the user with the tools to e Simulate and provide a record of flows and pressures in an existing mine e Perform what if simulations for planned new development e Help in short term and long term planning of ventilation requirements e Assist in selection of types of circu
84. provided the simulation is paused and none of the above conditions are violated Failure to follow the above rules may produce unpredictable results or program errors Ventsim Visual User Manual Page 215 23 7 1 Instantaneous Results 23 7 Viewing Results The dynamic simulation will show the results every update time interval on the screen so gas temperatures and airflows can be tracked through the mine during simulation E ge x e n e Ventsim Visual blue_sky vsm Example Metal Mine with Problems File Edit View Savedviews Run Connect Tools Settings Window Help PHOBOS SB amp ARO outon Ed cas y co y ppm e T Airtiow y Quantity y m3 s a BJ leede 2782 5E 2791 2N 47Z Airsimulation successful Compressible Yes NVP Yes airways 527 23 7 2 Historical Results Any monitor can be viewed during or after a simulation by pressing the EDIT or VIEW toolbar from Monitors 23 7 3 Storing a static graph image of results button and left mouse clicking on the monitor icon A graph will show allowing the user to view a wide range of ventilation conditions at that location in the model Ea Seis e Rock Temperature Sigma Heat Heat ei ON d o d o d o o d PP S amp S Lef e ei A e e e ESE H S Simply press the camera button on the graph form to make a static copy of the currently displayed airway monitor results at that location This will no
85. resulting in poor performance and excessive power consumption The fan efficiency and power consumption can be examined under the Edit Box fan menu Ideally the fan efficiency should have the operating duty point close to the maximum fan efficiency A further way to boost fan flow and efficiency is to ensure an evas is fitted to surface exhaust fans Fan evas s reduce surface velocity pressure losses increasing available fan static pressure to overcome mine resistance The overall effect is improved airflow at a similar cost Finally overall model influenced by the throughout a model efficiency is largely configuration of fans The use of in series Y EDIT 1 always selected Airway Heat Fan s Contaminant Information Notes 1x FAN 900mm Development fan Operating density 1 16 kgim3 Duty FTP 2039 2 Pa Q 14 5m3 s Eff 68 5 Pwr 42 0kW Pressure Efficiency Power Efficiency Curve Quantity Air simulation O APPLY OK CANCEL booster fans underground for a single primary ventilation circuit should generally be avoided if possible as fan efficiencies are compounded as the same airflow travels through each fan booster fans may however be useful in directing airflow into parts of a mine which would otherwise require inefficient regulators on the primary vent flow to do so The result compared to a single pass fan system is higher power for similar airflow The ov
86. round airways with a diameter of 3 0m This can provide a quick way to group edit and change layers for multiple airways New airways constructed will inherit the layer numbers of the airway they are constructed from If no airway exists new airways will use the default layers set in the Display Manager Hint Because primary and secondary layers can used together this creates an opportunity to create a filter using both layer systems If for example primary layers were assigned as different regions of a mine North South East and West for example and Secondary layers was defined as different functions Shafts Ramps Ore drives for example then by individually setting the Primary and Secondary layers the following examples could be easily viewed e Allramps in the North Mine e All ore drives in the East and West mine e All ramps and shaft in all mines 15 7 Summary The information in this Chapter explains only the basic techniques to establishing working ventilation models To create a truly representative ventilation model airway sizes and resistance must be accurately established ventilation controls such as doors or walls must be placed in the model with correct resistances and many other important factors such as shock losses considered For further information e See the Tutorial part of this manual Ventsim Visual User Manual Page 168 e Check the www ventsim com website for newsletters and forum information
87. same friction type eg rough blasted walls Selects all airways with the same shock type Selects all airways with the same fan Note that while fan types cannot be changed in multiple headings however fans can be turned on or off over multiple headings Selects all airways with the same air type for example exhaust Selects all airways with the same heat type eg trucks This may be useful for example to rapidly change all similar heat sources in a model to a different heat source for example change all Truck Models from ABC500 s to ABC750 s Selects all airways with one end that are not connected to others and which are not flagged as connected to surface or marked as allow closed end This function is useful for quickly editing new model creations from a DXF file for example which may have lots of dead ends and development stubs eg truck bays that need to be flagged or deleted to prevent no entry exit errors in the simulation Note that this function should only be used when all valid connections have been accounted for Similar to the loose end selection but only selected airways with no connection on both sides Select airways with the same sourcing contaminant type This selection was included to allow rapid definition of different air types in a mine by using the contaminant finding function For example is a smoke sourcing pin was placed all airways downstream will be turned red for contam
88. selected from the shaded squares See the Staging section for more information on this Entry 10L Exit Surface T48 Figure 9 3 Set airway names coordinates and stages Sets the physical size and shape characteristics of the airway Ventsim Visual User Manual Page 93 Type Custom K Ent DES aca 40 m Width 40 m Height 16 0 m Area 0 0 m2 Obstruct D oe Backfill Figure 9 4 Set airway physical characteristics Type Allows a preset type of airway to be specified which will automatically set the airway profile dimensions and friction factors Pressing the TYPE T button will open the PRESET form where airway preset types can be entered or modified If an airway type is modified all airways set to that type will be automatically modified during subsequent simulations Shape Sets the profile of the airway If the shape chosen is irregular the Width box will be changed to Perimeter the Height box will be hidden and the Area box will become editable Square Round Arched an airway with arched upper corners Shanty an airway with one side higher than the other Irregular an undefined shape characterised by area and perimeter e If the shape chosen is round the Width input box will be changed to Diameter e If the shape chosen is irregular the Width input will be changed to Perimeter and the Area box will allow data entry e Further profiles can be created in the Presets
89. simulated in the model The calculated flow in the airway This number can be modified to provide a resistance based on the frictional pressure loss entered below The calculated resistance will be entered in the resistance box as a custom resistance The airway WILL NOT be fixed to this flow rate and will automatically recalculate next after the next simulation Use the Edit Box gt FAN Tab gt Fix Flow function if this is required The calculated pressure drop in the airway This number can be modified and will be used to calculate a resistance for the airway if an equivalent Options flow is entered in the above box Surface Close End The calculated velocity of air in the airway This is the Show Data Exclude average velocity of air across the airway area and is Read Only and cannot be changed Fix Direction Group d Length 1163 m Controls various attributes relating to the airway behaviour and identification within a model KSE 00 Diffuser 16 0 ep Connects the airway to the surface allowing it to freely Orifice 0 0 mo exhaust and intake air from the surface atmosphere The airway end which is not connected to any other airway is em Pa 2 assumed to be the end connected to the surface If both airway ends are connected this item is ignored by the a Al Level simulation The exit to the surface is assumed to be at etm een the elevation of the airway end Barometric pressures at this point will be adjusted for any diffe
90. simulation the TWL may be underestimated for workers around radient heat sources such as machinery or hot rock ACPM Method Developed in the USA the Ar Cooling Power M scale method is based around limiting skin temperature factors as an indicator to body core temperature The method is in use in most North American mines Results are highly dependent on clothing and work output factors Ventsim Visual defaults to standard light clothing Again the method ideally requires globe temperatures for accurate resutls As these are not available from a simulation the ACPM may be underestimated for workers around radient heat sources such as machinery or hot rock Kata Method Developed in South Africa the Kata cooling method uses the wet bulb and air velocity to develop a heat stress index representing cooling ability of the air Sigma Heat The sum of sensible heat and latent heat in a substance above a base temperature typically zero 0 degree Celcius or 32 degrees Fahrenheit Sigma Heat is independent of dry bulb temperature relying only on wet bulb temperature and pressure to derive it value Enthalpy Similar to Sigma heat it is the sum of the total heat content of a unit weight of air including the water vapour at typically zero 0 degree Celcius or 32 degrees Fahrenheit Unlike Sigma Heat it does not however take into account the adiabatic saturation process and is therefore not as useful pscrometrically Energy Flow The sum prod
91. temperatures Warning Perhaps the biggest mistake in attempting to simulate heat underground is trying to apply a heat source to an airway carrying small amounts of airflow While this may be possible in real life due to perhaps only a short time of exposure because Ventsim Visual uses a steady state thermal simulation the heat is assumed to apply continuously and can result in extremely high air temperatures As the thermodynamic equations are only optimised for a certain heat range up to around 100 degrees excessive heat will produce a simulation error Sensible heat is the application of heat to the air with no change in moisture content The situation applies to dry heat sources such as electric motors from fans or pumps radiating heat from hydraulic or working equipment or frictional heat sources from conveyor belts or crushers Note that all ventilation power underground such as fans and fixed flows or pressures are automatically assumed to be sources of heat in Ventsim They do not need to be entered as separate heat sources Diesel engine sources underground are internally converted to a mixture of sensible and latent heat for simulation Due to thermal inefficiencies a diesel engine of a rated power will produce nearly three times the heat of the rated engine power assuming no energy is converted to useful work Ensure when entering diesel heat sources that only the engine power diesel equivalent is entered not the engi
92. the Velocity cannot be changed to km hr as this would represent a different value scales and the underlying Ventsim equations are hard corded to use m s Imperial Unit A text name describing the imperial units Multiplier The factor used to convert from metric to imperial Ventsim Visual performs all internal calculation using metric formula and methods converting displayed data back to imperial if set in SETTINGS The factor is used to convert to and from metric to imperial and will result in errors if not properly set Addition This factor is only used in converting degrees Celsius to degrees Fahrenheit and added to the metric value before multiplied in imperial Always Metric Forces Ventsim to display the unit in Metric even if the global Ventsim unit setting is set to Imperial 5 8 3 Natural VentilationApply natural ventilation pressures to the simulation model based on the air density in 5 8 4 Compressible Flows 5 8 5 Simulation Accuracy 5 8 6 Settings every airway Natural ventilation is applied based on the differential of density between air at an equivalent elevation outside of the mine and the air within the airway Therefore for accurate analysis it is essential that heat first be correctly modelled and correct outside temperatures added Unless heat is modelled accurately it is recommended that Natural Ventilation be turned off Caution Natural Ventilation may result in fluctuating airflow and t
93. the contaminant tool button is Value clicked For steady state simulation this would normally be the maximum concentration expected through the model unless recirculation or upstream contaminant sources are present For dynamic state simulation this should be considered the average concentration of the contaminant volume to be cleared Diesel Particulate The default diesel emission factor to use if the preset heat sources do not have a specified Emissions factor It is normally recommended that preset heat sources each have their own defined diesel particulate emission value See DPM Simulation for further information Dynamic Contaminant The value at which dynamic contaminant simulation will stop if every airway in the mine is Threshold below this number It is suggested this threshold should be set to a number equivalent to Safe access for the area 12 4 1 Dynamic Simulation El Dynamic Dynamic Increment Frequency Airflow Simulation Frequency Log Data Frequency Screen Update Maximum Data Logs Maximum Subcells Simulation Pause ms Simulation Total Time Dynamic Dynamic Ventsim Visual User Manual Page 135 Dynamic Increment Frequency Airflow Simulation Frequency Log Data Frequency Screen Update Maximum Data Logs Maximum Subcells Simulation Pause ms Simulation Total Time Dynamic simulation factors control simulation parameter required during dynamic simulation or when using the VentFIRE option
94. the desired graphics 31 2 1 No Graphics The airways may be hidden or invisible or located off the screen Shown on Screen Resolution Use the VIEW gt FIT ALL command to make sure the grpahics are relocated to the screen If no graphics show use the VIEW gt SHOW ALL to turn on all hidden layers and levels If still no graphics show ensure that airways are still present in the model by running the RUN gt SUMMARY menu option and ensuring a number of airways are present Finally make sure that options such as VIEW gt HIDE ZERO FLOWS and VIEW gt HIDE EXCLUDED AIRWAYS are not turned on 31 2 2 I can see airways The screen may only display the raw airways but no other information but no text arrows nodes Resolution The option to display text or arrows may be turned off press T or A respectively to turn back on or use the sidebar toolbar menu If this does not work the LIMIT command may be turned on This command hides text nodes arrows if the airways is not specifically set on the EDIT form to show DATA Turn the LIMIT option off using the LU button Ventsim Visual User Manual Page 270 32 APPENDIX E SIMULATION ERRORS The following messages may be shown if errors are present during model simulation To select and view EEN ag Wee no entry connection in the Error List Box at the lower right corner of the 4inway 33 Wamino no ext connection way 96 Waming no entry connectio
95. the simulation Warning Dynamic contamination in Ventsim uses a simplified homogenous distribution algorithm which ignores the slower turbulent boundary effects of airflow along a rough passage and around corners and the higher centre airflow velocities Due to this leading and trailing effect Ventsim may slightly underestimate the speed of gas distribution and also underestimate the speed at which all gas is cleared from an airway The simulation should only be treated as a guide Dynamic Contaminant can be applied and set in the EDIT Contaminant box of any airway or by using the SMOKE icon on the toolbar There is no limit to the number of contaminant sources that may be simulated simultaneously in a model Ventsim Visual User Manual Page 179 ES EDIT 1 airways 100 0 r File Select Airways Tools Airway Fans Heat Contaminant Gas Dynamic Sensors Info Notes OFF Activate Contaminant Contaminant Contaminant Concentration 2000 CO ppm Dynamic Contaminants a Fired Rate 2 Linear Decay 3600 Second E Logarithmic Decay O Explosives 500 kg Moderate 4 Sourcing Location Tool Report Smoke Report Fresh Figure 18 2 Placing a contaminant in an airway Dynamic Contaminant Sources may included e Fixed Time Release e Linear Decay Release e Logarithmic Decay Release e Explosive Gas Release 18 3 Fixed Linear Logarithmic Release Selecting these options releases a contaminant for a limited amoun
96. the user can change the name to LOG MainDecline80D When exported to the Ventlog database the name MainDecline80D will appear in the database with the correct coordinates and directions 9 8 1 Sensors The sensor option in the edit box allows live imported data from the optional LIVEVIEW module to be placed and displayed on an airway The dropdown lists permit the specific sensor to be attached to an airway and also offer an option to modify the simulated conditions in the airway during LiveVIEW simulation See the Live VIEW section for further information d A e 4 9 m s SAFV1 File Select Airways Tools 2 e 1 S G H4 1 Airway Fans Heat Contaminant 39 6ppm SCO 1 Sensors Info Notes Sensors 25 0 C SDBT1 TT 23 8 C SWBT1 San v 4 881278 SCH41 v 2 1278 sco1 v 39 64058 ser Mk SWBT1 v 23 7983 Yes NVP Yes airways 526 Figure 9 15 Attaching sensors to airways Ventsim Visual User Manual Page 114 10 1 1 Fit All 10 1 2 Zoom Out 10 1 3 Flight Mouse Up Mouse Down Mouse Left and Right Mouse Scroll Button Escape Key 10 1 4 Select Level 10 THE POPUP CONTEXT MENU The popup menu activated at any time by a Right Mouse Click provides a useful collection of commonly used function While most of the functions are also available from the toolbar or top menu the popup feature can save considerable time as the mouse cursor is not required
97. to 3D Calculate VRT Simplify Parameters 20 0 Y Joined Angle Maximum 60 0 m Joined Length Maximum Simplify Opti Use combined lengths V Ensure no resistance presets filtered Establish the surface connections Ventsim needs to know which airways connect to the surface otherwise the program will consider them as dead ends where no air can flow Ventsim Visual User Manual Page 253 ewe ge rae a airways 033 File Select Airways Tools Fans Heat Contaminant Gas _ Information Notes og Index 1 Unique 5942 Op Connect free end to surface 2 Y Suface F Close End E Show Data 7 Exclude E Square E Fix Direction 7 Group Custom Fuaz nn m Establish airflow by placing a FIXED FLOW on one of the major surface connections At this stage we are not trying to simulate an actual fan installation but just trying to establish that air can travel through all airways in the model Run Tools Window Help Airflow y Quantity Ds Press SIMULATE Many warnings will show indicating El Hide airway dead ends which are not closed off or connected to ont other airways Ensure that airflows are travelling through parts of the mine where is should travel Use the flow animation and or airflow colouring to indicate good and bad flow areas If areas are not flowing air and that should be flowing air check for any break
98. to initially have up to 2000 ppm of CO carbon monoxide immediately after blasting and a clearance time of 15 minutes Therefore a dispersion factor is entered into the EDIT box to obtain a similar result the setting unit can be changed to CO ppm if the user selects and the explosive amount set to 200 kg When dynamic simulation is chosen the concentration of fumes in ppm CO is shown through the model second by second Clearance times can be established when concentration falls below a specified limit for example 25 ppm At any time the colour legend and limits can be changed to show the concentration as colours Warning Dynamic contaminant simulation has many factors which can initially be difficult to predict It is highly recommended users calibrate their models with actual data if they have the opportunity The simulation does not replace real gas measurement or observation when entering blasting areas Ventsim Visual User Manual Page 182 18 5 Dynamic Gas Simulation Dynamic gas simulation simulates the time based spread of gases through a mine Once again the dynamic monitor functions can be used to record historical gas results from the simulation at different locations For further information see the GAS SIMULATION chapter 18 6 Dynamic DPM Simulation Dynamic DPM simulation uses diesel heat sources to calculate diesel emissions through the mine The DPM levels are spread through the mine over time and can be recor
99. traditional means 3 1 Display Ventsim Visual default Three dimensional 3D perspective views are rarely used in CAD or Mine Planning uses a 3D perspective packages except occasionally for final presentation purposes The perspective view tends view to distort distances and true directions and is therefore largely unsuitable for detailed engineering drawing An orthogonal non perspective view however is not required for ventilation modelling which relies more on effective data presentation A 3D perspective view is the way we look at the world and when used to view computer models it is natural and easily understood particularly to someone unfamiliar with your model Ventsim Visual User Manual Page 20 3 5 1 The Ventsim Visual Approach To create a user friendly graphically rich program and interface which shows the maximum amount of relevant data in the most efficient and understandable way Colour and Data Manager Airway solids shown with true dimensions and shapes allow quick appraisal to check whether dimensions are as intended The author has found numerous examples of Ventsim Classic 3 9 models loaded in Ventsim Visual that immediately show inadvertent incorrectly sized or shaped airways which may prevent the model from simulating or balancing as expected A perspective view also permits closer visualisation of specific parts of a model while other parts are hidden or obscured by distance In clutter
100. will be drawn on the specified elevation Shows all elevation ranges for the model Turns on all level elevations views and includes airways and references outside of the defined elevation ranges Shows all layers primary and secondary in the model Turns on all layers so all airways graphics will be visible Hides airways with no flow This function is useful for hiding disused or unventilated parts of a mine so they do not clutter the display Airways with no flow or airflow below the level set as zero flow value in the Settings menu will be shown as transparent or hidden depending on the transparency settings described above and the transparency amount set in the Display Manager Hides airways which have been set as EXCLUDED from the model This function is useful for hiding parts of a mine which are not required to be simulated or are not set to be part of the current simulation model The exclude options for airways are available from the EDIT box Hint Old sealed off development or future development yet to be mined can be excluded from the model to speed up simulation and display of models Excluded airway can be hidden to simplify the display but can be shown and converted back to normal airways at any time if required 5 4 Saved View Menu Saves the current view and stores the save name in menu for future recall Save view will save all attributes in a view including RL levels layers and display options Saved views can
101. will be loaded automatically next time the program is run Warning if the model has become corrupted for some reason there is a possibility that the auto saved model may also be corrupted For this reason it is recommended that a model be regularly saved to ensure that good working copies are available as backups if required Maximum Airway Automatically performs an heat simulation when the file is loaded This will update heat Numbers simulation summary parameters and a number of calculated heat parameters only available after a simulation Maximum Reference Automatically performs an heat simulation when the file is loaded This will update heat Elements simulation summary parameters and a number of calculated heat parameters only available after a simulation 12 2 3 License Settings Alters license activation settings which may be required to allow Ventsim to access the internet to validate licenses Ventsim normally uses Microsoft Internet Explorer settings to access the internet however on occasions third party programs like Ventsim may be denied direct access requiring the proxy name and proxy port address to be entered manually These values can also be adjusted in the License Manager form Ventsim Visual User Manual Page 125 12 3 Graphics Settings Control the various aspects of the screen graphics and presentation ZG Wentsim Visual Settings General El Graphics El Background Background Picture Nil Background Pictur
102. will increase the available operating pressure curve and power draw for the fan while lower air densities will have the reverse effect This can be an important consideration when selecting or designing a fan for a particular area in a mine Note that for Ventsim Visual Standard air densities are assumed fixed at all locations in a mine If fans are forced by other model conditions to run beyond the limits of the fan curve a warning showing stalled low pressure or negated will be shown during model simulation Stalled fans occur when the fan pressure build up is greater than the capacity of the fan curve to accommodate Ventsim Visual reduces the airflow quantity to a point where the fan pressure is no more than the maximum pressure specified in the fan curve Low Pressure fans occur when a fan pressure falls below the lowest pressure point of the fan curve but is still operating above a zero pressure This may occur when a fan is run with too little resistance or the fan is a high pressure type being used in a low pressure application The fan pressure curve in this case may not extend down to the point the fan is operating at This is undesirable as the program must make assumptions as to what duty point the fan is actually running at In addition the fan is unlikely to be running efficiently at this duty point To prevent this warning simply extend the fan curve to a lower pressure point Negated fans occur when the fan offers no us
103. with Fan Total Pressure curves Total Pressure The use of fan total pressures fan static and velocity pressure is considered the technically Method correct method for simulating airflows as both static and velocity pressures contribute to airflow through an underground mine Ventsim Visual can help predict a fan total pressure curve from an existing static pressure curve using tools in the Fan Database Editor The total pressure method assumes the full fan total pressure is available to push or pull air through a mine The method also considers system velocity pressure losses to the atmosphere for example from exhaust shafts and incorporates these into the simulation The fan total pressure method relies on the user accurately considering fan exit losses with appropriate diffuser sizes shock loss factors and resistances as total fan pressure is never fully available to pressure the underground air flow Fan outlet configuration outlet flow direction changes and the inclusion of diffusers which boost fan static performance and reduce exit losses or other exit devices such as fan shutters need to be fully considered if Ventsim Visual User Manual Page 154 Should Use Static or Total Pressure they have not been incorporated into the fan curve otherwise the model may over predict the available pressure and flow for the model To use the Fan Total Pressure Method ensure all fans contain a Fan Total Pressure Curve If any fa
104. 1 288 104 51 470 438 7 60 24 74 010 3 601 1 493 081 1 875 683 1 627 305 510 230 700 205 6 1 288 104 51 470 438 57 84 30 80 020 4 202 1 725 931 624 181 550 203 4 690 180 2056 1 288 104 1 470 438 8 08 86 030 54 803 1 978 782 262 812 228 011 3 203 058 205 6 1 288 104 1 470 438 8 3 5 404 2 221 632 125 295 108 704 2 805 304 1 288 104 1 470 438 8 57 196 005 2 464 482 66 171 57 409 2 772 732 2056 1 288 104 1 470 438 8 81 154 060 6 606 2 757 333 57 470 49 860 3 025 047 1 288 104 1 470 438 9 11 160 070 7 207 3 000 183 34 559 ena eem 1 288 104 1 470 438 9 3 166 080 7 808 3 243 033 21 847 3 344 805 1 288 104 1 470 438 9 5 172 090 2 409 3 485 883 14 392 3 552 926 1 288 104 1 470 438 9 8 Size Si Width Height Fixed Cost Mining im Name Wall Type a Cost a Cost Hora 6 0 Smooth Blasted 7 60 Hora 6 6 Smooth Blasted 7 66 Hora 7 2 Smooth Blasted el II O Life yrs 5 E Discount 10 lt 3 airway segments selected total length 394 1 m Fan Cost 1000 Adjust Hows Figure 26 2 Example of a Financial Simulation Table Ventsim Visual User Manual Page 235 Maintain Flows Simulation Adjust Flows Simulation Input variables required The sys
105. 29 2 143 Cooler RH Moisture 0 0097 kg kg 423 0 0091 kg kg 99 9 VRT 56 3 C 56 9 Sensible Heat Addition 3472 9 kW Latent Heat Addition 57 0 kW 157 9 nia wu ox cancer APPLY OK CANCEL Simulation O Dry bulb Units m3 s Coords 1992 7E 2065 6N 930Z Figure 20 2 Example of an inline cooler chilling ALL airflow Ventsim Visual User Manual Page 194 What type of refrigeration plant is it Refrigeration Plant Performance T Index 355 Y Unique 2833 Sims Blue_sky vsm VentSim Demonstration Network E pees Rock Conditions ble 0 0 kW Thermal Conductivity 2 00 Wim hs 0 0 KW C ThermaiDittusivity 1 500 mais ie Co Specific Heat 790 0 Jik GG ei cl Rock Density 1688 kg fon 0 000 ov bh E CH 00 e Wetness Fraction me sal 00 ee Age or Year Entry Eoo year init To E Age or Year Exit 5 00 year sar 0 0 gisim Reverse Spectrum Restore Colours MELODIA Au face on 929 0 m 925 0 ilb 141 142 C E m WE e Cooler re 0 0075kgkg 65 6 0 0075 kgikg 65 7 a s68c 56 9 C 85 5 Sensible Heat Addition 54 kW Latent Heat Addition 7 9 kW Units m3 s Coords 2196 0E 1987 7N 933Z Figure 20 3 Example showing same inline cooler chilling only 40 airflow Discussion It is important to note that in both cases 3500kW of heat has been removed from the air Downstream from the refrigeration unit the differe
106. 37 AGA JADVANCED ee 237 26 2 COST DATA FUNCION E E E EEN ee 238 POZA EELER 238 26 3 VENTILATION ON DEMAN Dios sssssesssissziissssi sirin Ee 239 26 4 PAN OPTIMISATION au E E E E E 240 TUTORIAL MODEL EXAMPLES eesssesseecsscesseccssecseccsecesseccseecseccsecoseeccseccseccsecoseecsseecssccsecosecesceccssecsecosecesseesseesseeeseees 241 27 1 EXAMPLE DE 241 PAL Suggested Ee E 241 27 2 EE leet 248 2724 SUOESCO STOPS EE 248 27 3 EXAMPLE 3 IMPORT A COMPLEX MINE DESIGN cccccceseeeeeseeeseeeceeececeeeeeeeeeeeeececeuceeceeeeeeececeeeeeeeceeeceeeeseesececeseeeseeeeeeeees 252 APPENDIX A GLOSSARY OF FER gedet EEN gege eee 256 28 1 A GLOSSARY OF COMMONLY USED TERMS as A AA A A A At 256 Dodi EE 256 MDa PONC E 256 E E Ee EE 256 PEA DAE EE 256 2815 SENDO ES SORDO ais 256 LE LO ECO COS A AAA E AAA AA A A IDO 256 ZEA ERCUONTOCIONO TACO ia Add 256 28 18 FACU TOS ii SS od 256 MSD ECON DOWN as 256 E LO OA Y CLOSS MECO SAS AAA ede mualanetaeedntaes 256 Vly Eege EE 256 PE TAD AOA NE DEE 256 ZS AMS INCOADO ia 256 2S TIA EE 257 Se E IPUR Aa 257 ZO LLO PRESSURE IO rain a caia 257 LO LL Lis e te 257 DTM e ee CO PODER OPE PE E Em baa ses tas gases nF cate SaaS TE 257 DS AAD Thermal EE 257 ZS E20 Thermal CON e EE 257 DE L2 Wene e EE 257 26 122 Relative Umid EE 257 E EE Ee EE 257 29 APPENDIX B SUMMARY OF DATA TYPES iia a A EE a 258 29 1 SUMMARY OF THE MAJOR DATA TYPES A A ede 258 ZDT NN 2
107. 4 36 SC 42 68545 28 Dec 2011 21 04 36 SDBT1 25 28 Dec 2011 21 04 36 SDBT2 29 3071 28 Dec 2011 21 04 36 SWBT1 23 7983 28 Dec 2011 21 04 36 SWBT2 23 76999 28 Dec 2011 21 04 36 II 24 3 Managing Connections Once the LiveView connections have been established they will be displayed in the connection list in the main LiveView form You can edit delete and make duplicates of the connections using the appropriate button at the base of the list You can also edit the connection by double clicking the name in the list The connections can be simultaneously tested by clicking the VALIDATE CONNECTIONS button Any issues will be reported in the results box and the combined data imported with be shown in a datasheet If a connection has failed edit the connection data and test the mapping and sensor data for more specific error reporting Ventsim Visual User Manual Page 225 LiveVIEW File Edit Data Connections ei EXCEL Data ACCESS Data TEXT Data SQL Data MOVING DATA Fo oll ole Ga al fo Validate Connections Connection Results Successful Connections ACCESS Data TEXT Data SQL Data MOVING DATA Failed Connections EXCEL Data EARCH 24 4 LiveView Settings 24 4 1 Set Sensor LiveView can be set to periodically read and display sensor data in the model The sensor Simulation data can also be used to simulate conditions in the model and a number of simulation Options opt
108. 58 AS Het ANON EE 258 DATE E 258 DO TAG FW OY APRA DUS dd a 259 29 Lo VENETO FOWE e EE 260 LI LO INCOMODA 260 a NS Eeer 261 ZO LOs eege et 262 29 95 dE ni aiii 263 2910 Meds i da 263 e EE ee 263 30 APPENDIX C ICON PICTURE GUIDE sitas ansiada didas 264 30 1 AIRWA TICON nt wdeaaneearseasecaie tata cceatiiate anata deat 264 30 2 CUSTOMIZED ONS EE 264 E FONS EE 265 3022 BIOCKCO AIWOV E 265 3023 AWAY RESISTANCE 265 302A TETAMI EE 265 30 25 ICO PIESSUIC eege 266 3026 EE 266 A 266 3028 COMANDO EEN 266 A E 266 30 2 10 Thermo dynamic Heat or Moisture Source 267 30 2 11 Thermo dynamic Cooling or Drying Source En 267 BOZ SEENEN 267 30 2 13 SU ace CONMECtea AIW GY ii a ANAT 267 30214 Unkown Arway ENS 267 BO EE 267 30216 GE 268 302 17 TODS URUCEON EE 268 30 218 Ee 268 3021 SHOCK LOSS EEN 268 31 APPENDIX D DISPLAY PROBLEM CA oo 269 31 1 PIARDWARE PROBLEM Sera A 269 31 1 1 Screen fails to display after coming out of sleep bvbernotion 269 Page 14 32 33 34 Page 15 31 1 2 Anti aliasing does not work is very souwi 269 31 1 3 CUSTOM ICONS CANNOL DE USED id 269 31 2 SEENEN 270 342 4 NoGraphics Shown ON Ea 270 31 2 2 can see airways but no text arrows NOES cececscessesssessesssesscsssesscessescessessesscessesseessesseense 270 APPENDIX E SIMULATION ERRORS scr 271 32 1 WARNING aora 271 32 1 1 no entry airway or surface COnnechon 271 32 1 2 no
109. 6 SE SEELEN 117 O NON 117 TOTO ENEE 117 sO i ines by Ry A O 117 DOTA De EI 117 d Re EE GE 117 10 1 14 Action Data and View Toolbor ee 117 TOTS gt RESET DISPO ATAN id 117 11 PRESETS in 118 11 1 DREEMEN 118 RS E D GE EE 118 EZ SO e E 118 11 2 ACCESSING PRESETS cid 119 TL2 119 A d ENEE 120 TL23 e EE 120 LS A a ie 120 11 2 5 Layer Prim Layer SEAT TY 120 TL EROS A AAA E AA AAA A AS 120 TEZ Ze ele EE 120 TAL ROMS ee 120 TL29 A A EE 121 DD ZA Ad o N 121 11211 COMPUSO EE 121 117212 ALO NA 121 TL ee EE 121 12 SETTINGS toa 122 12 1 COSTING AAA AA A A Sockeye es Eee AAA 122 12 2 ETAN eY E E E E A AA EE E E E EEA EAT 124 TULL Arway DE US SAS AAA 124 O e 125 Y Ee le Ce 125 12 3 GRAPHICS an de 126 1231 BOC OUNAE Aa 126 RE O e TEE 127 DPBS A ee E 128 1234 ee He 128 123 5 ee EE 129 1236 OA 129 EE EE 130 TS a a 130 12 4 E O DEE 132 TL eo 132 BAAD eege 135 24 1 Eelere lee AAA AA A O 135 12 4 1 Simulation Environment ADVANCED ccs cccsesssesesssesssscesescesssscesesssesesscesenscesnecesnscesenseeeees 137 RE eeler 139 TES PIO VO SSA 140 1244 Fire PREMIUM RE 141 1245 GOS asec a a a A a 142 124 6 Heat ADVANCED ososcnacontal didactica 142 PAZ RECKCUIGHON EE 145 12 5 VENTSIM SYSTEM SETTINGS id td Aan ised Aine die ena daa 145 13 HEAT REN E VE 147 TS LL AOW e E 147 DD De ANGI OWE LAA AAA A A do 147 Page 10 14 15 16 17 18 1
110. 9 Page 11 13L nn A 148 TB DIES aaa dai 149 A e TT 150 IS LOs Water FOW E 150 FANS iaa Rana aca 152 14 1 FANIA TABA SE eta 152 TATI EOL DIO Ono 154 14 2 PANIP RESSURE PES 154 14 2 1 Simulation Handling of Exit Velocity Pressure eege 154 14 3 BAN DATABASE MENUITEM Ss ee dee 156 BUILDING MENSCHEN 158 15 1 EIERE ee a 158 15 2 IPYPES OR lee 158 152A EE 158 15 3 INITIALMODEL CONSTRUCTION Seeerei 159 15 3 1 Manual Scaled ee e de D 160 15 3 2 Manual Schematic Construction EE 160 15 33 SSPlCOGSICEE Tex IMPDO eege 161 1534 TEE 161 RE CR eege e 163 15 4 CREATING PRESSURE FOR FLOW Sei ts 164 TAT e EE 164 TSAZ e E ele iia On 164 1543 E E A O 165 15 5 SIMULATING AIRFLOW IN A MODEL isc 165 15 51 Ventilation Keele EE 165 15 5 2 Ventilation Ducting and Blind Heodig EE 167 15 5 3 Interconnecting Mine AWAY S AAN EA AAA 167 15 6 TANGA VERS td do 167 15641 PRIMO LLOC EE 168 1562 Secondary LIVETS AAA AS A AAA aces eae 168 1563 ISIN Eer EE 168 15 7 A 168 AUXILIAR VENTILATION AND DU CTS ran 170 16 1 Che eene EE 170 16 2 APPLYING VENTILAMON TO DUCTS E 171 CONTAMINANT SIMULATION STEADY STATE sccccccssscccsssssssssssscccccccssscsssssssscccnscccccessssscessssccccccccccccessseeesnsssceees 174 17 1 INTRODUCTION Landis css AS A AAA AAA AAA eA 174 17 2 EENEG eege 174 17 3 DAM EEN 175 17 4 ET 175 17 5 REVERSE CONTAMINAN otra dd oda lado lo US 175 17 6 FIND SOURCES aer ici 176 17 7 A AT 177 DYNAMIC SIM
111. A REICOSC aa a aiaia 44 Foure Se CONCA dE 47 FONES O FNG ANI DA E 48 Figure 5 10 Example showing a ventilation fan recirculating oi 53 Figure 5 11 Example of Summary Output with Description 57 PIQUE S 12 Mpe Sumnar yV DAS AAA AA AE AAA AAA ERASE 57 Figure 5 13 Spreadsheet view of model with selected dorto 60 Figure S I4F EE a SAS ES ASAS AA 61 PIQUE 5 1 3 Te SIMPINCIOIOO OX nda 61 Fone S 16 Binding TOO Kor n oc 62 FIQUIE 5 17 Duplicate Finding e TEE 63 Fone S 18 FE EEN 64 FIQUIC 3 19 CONVERTIDA dia 67 Fig re 6 1 Example of limiting text Ae rida 71 Figure IL OVE OG OGD DIS PI lt A A AAA AA AAA ASA AAA A uA is 76 FIGULE 722 Perspective DIS A AAN A AAA ANA AA AN 76 Figure 7 3 ADIMOUGN speed CONTO SS AAA AAA 77 Figure 7 4 Manual edel e ee eege Ad 78 Figure 7 5 TNE Vent DUCE Builder Dialog BOX iii a a aia 79 Figure 76 OMI BOING e E 79 TEEN 80 Figure TO DOC HON ODUOMS ii ANS AAA AA AAA ASA AA AAA 81 AQUELS 7 I ANCOIWATESO PM EEN 81 Figure 7 10 Contamnant ele 82 Figure 7 11 Contaminant OPTIONS 1 RA RA AA AARE ada 84 Figure 8 1 Select a data category followed by a data type EE 86 EE E a0 Gal fo a cRerree t oido 90 Figure 9 2 AWAY EGE ELON OM Dio 93 Figure 9 3 Set airway NAMES coordinates and STAGES EE 93 Figure 9 4 EEGEN AS 94 Figure 9 5 FUFNCRANWOY OP UONE dd ii 95 Figure 9 6 Example of use of fresh exhaust airway type colouring ssssssssseeseesesessesssescescessesssssessesscessesssssessesscsucensessessessesscesseusessess
112. Airways with a specified heat source will have these values applied during simulation The screen also shows the number of heat sources currently in use The form shows current names for these items and in the case of layers whether they are being used or not The names can be changed at any time and new layer names and air type names can be added Colour can be changed by clicking on the colour box There are currently 250 layers and 25 airway types reserved for use Present a summary of current fans and the basic characteristics of those fans eg diameter air density for the curve etc While the fan curve data cannot be directly edited from this screen you will need to go to the fan database function the fan names can be changed as well as the other fan parameters Fans can also be fully deleted from the model A read only column states the number of fans in use in the model Airways presets allow a specific size and type of airway to be set with pre defined dimensions friction factors and profiles Airways can then be quickly selected in the EDIT box to the preset airway type containing the preselected values Profiles allow custom profile shapes to be entered into Ventsim The first five 5 profile shapes square round shanty arched and irregular are preset and cannot be changed however the profile string is shown to help users define new profile strings Profile strings are dimensionless coordinates centred around an origin poin
113. CLOSED END option in the airway EDIT form 7 If any error or warnings show then correct the mistakes individually or grouped as required TO manually construct airways simply use the construction tools the draw move copy and delete buttons from the toolbar Airways can be drawn freehand on the screen with the mouse using the coordinates displayed in the status bar to guide the airway location Additionally coordinates for airways can be entered manually using the coordinate entry function or by simply clicking on an airway end while in the draw mode This method is generally suitable for small models less than several hundred airway segments Most airway models are generally fairly tolerant of misaligned or slightly misplaced airways providing approximate airway lengths are close to reality In many cases to assist with clarity airways can be deliberately moved aside and a fixed length function used to override the automatic length calculation to set actual lengths If the model is required to be true to scale then more accurate construction may be required and it is often better to import actual mine designs from CAD programs into Ventsim to use as a template to constructing a true to scale model 15 3 2 Manual Schematic In some cases a model schematic can be constructed to simulate a model A model Construction schematic may look nothing like a real mine but simply represent airways by a series of conveniently locat
114. End in the Edit box Any other orphaned airways will cause the simulation to show warnings Sets the number of attempts Ventsim Visual can take to achieve an acceptable error before the program abandons the simulation process The maximum pressure the simulation will allow between airways before a simulation error is reported This error may indicate unreasonable fixed flows or resistances which interact and cause large pressure changes in the model Modifies the Ventsim Visual simulation algorithm to give mesh forming priority to surface connected airways This normally ensure rapid solving of model simulations however for models with extensive surface connected airways this may cause simulation balancing issues and turning off this option may give better results Ventsim Visual User Manual Page 133 Shock Loss Type Stop Resistance Use Natural Ventilation Pressures Warn On Change Direction Water Suspension Checking Water Suspension Upper and Lower Velocity Water Suspension Minimum Length Zero Flow Limit Defines the shock loss method to use Ventsim Visual can be set to calculate shock losses using the equivalent length method orthe shock factor X method Shock loss calculations are necessary to estimate pressure loss due to air turbulence cause by a change in airway direction a junction or a change in airway size Note that changing this value in an existing model will result in Ventsim Visual r
115. H m3 s BAR fe DP OMS ly Draw Single Draw Continuous Draw Gradient Draw Coordinates Construct Duct am Construct Ramp T Convert Any Measure Convert DXF Refere AJAA Ol Coords 6058 1E 10851 1N 494Z Status Compressible No NVP No Airways Figure 15 3 Imported DXF Lines E amp Ventsim Visual II Beta Tas Terrain dxf gt en e e File Edit View SavedViews Run Connect Tools Settings Window Help Peas co ar ANO Ae PARADA T E BY s Favourite y Levels ym es T Airflow y Quantity slesl O Oj 0 Ol coor s 866 2 E 11852 6N 4972 Status Compressible No NVP No airways 488 Figure 15 4 Conversion of DXF lines to airways STEP 2 Modifying and Validating Import Data Once imported into Ventsim Visual the program will assign default airways sizes and shapes to all the imported airways Ensure you have default sizes and shapes set in the Settings menu that will approximate the typical sizes that are imported This will prevent having to re edit of ALL of the airway sizes and shapes although this can still be quickly done using the group edit command Import DXF Graphics Unlike line string data solid or wireframe graphics cannot be directly converted to airways Solid or Wireframe Data The data can still however be used to help construct airways by either using the referenced imported graphics as guides to manually draw airways or by usin
116. INE carrying fresh air and the SHAFT and the upper sub level carrying exhaust 4 Create some saved views showing the e whole mine with exhaust and fresh air showing e decline by itself e two upper sub levels and corresponding shafts 5 Initially set the default airway sizes in the Settings gt General gt Airway Defaults menu to 4 0 x 5 0m This will set all imported DXF airways to these defaults sizes and therefore the majority of airways will not need to be adjusted after importing 6 File gt IMPORT the DXF file into Ventsim converting the dxf centrelines directly to airways import option Another method is to import the lines as a reference only and then selectively choose or fence which lines to convert using the Airway gt Convert Centreline toolbar button option next to the ADD button r ae z gt gt wee 4 Ventsim Visual Tutoriali vsm D El ea File Edit View Save View Run Tools Window Help Jj F ld la B Y amp amp Contaminants Spread Mix D Loe 30000560I0 DS c Units Coords 17338 0E 11381 0N 1074Z Figure 27 11 Initial imported DXF strings in Ventsim Visual 7 Create an RL database with the RL MIN amp MAX covering each sub level range Use the TOOLS gt LEVELS menu option for this Ventsim Visual User Manual Page 248 fa Y wo worn OM on Figure 27 12 The Level Elevation database 8 Cr
117. ION STEADY STATE oi 174 18 DYNAMIC SIMULATION ADVANCED re 178 19 MULTI GAS SIMULATION ME A Lei EE 185 20 THERMODYNAMIC SIMULATION ADVANCED sseesoessosssesssessosssosesosesesssessoessosssosesosesosssesssessosssosssosesosssesssessosssoss 189 21 DIESEL PARTICULATE SIMULATION DPI a EE 196 22 STAGING ALE VERSIONS Jorin css 200 23 VENTFIRE SCENARIO SIMULATION PREMIUM ssssssressssesecsesecscsersssssersssessssersssenesscnesecscsecsssessssesessssessscesesess 207 24 LUIVEVIEW gt IPREMIO Moa 220 25 RADON SIMULATION PREMIUNI iia 231 26 FINANCIAL OPTIMISATION ADVANCED Disc a 234 27 TUTORIAL MODEL EXAM PLES cia A EA O A A AAA 241 28 APPENDIX A GLOSSARY OF TERMS scccntsscccsnssiccessssiacsnnnssacesassdacessssscnsnunsdaceansedecsssissensnndssccsansadadesussdcqennnedacssndedccereies s 256 29 APPENDIX B SUMMARY OF DATA TYPES sisiscccccssscssccsssasccectsasscessiessscpatasccecsissscessdvsssenstesccecssssssessdesssepabasccessuacsseesvess 258 30 APPENDIX C ICON PICTURE CTT 264 31 APPENDIX D DISPLAY PROBLEMS eessen GEERT EENEG EERSTEN AED 269 32 APPENDIX E SIMULATION ERRORS sscssssscscacusssssacsssossacanssscacusssesacssseseacnsessbacdusssssacussnssecuasseeacussssdadssessonusessbadeasessaessins 271 33 APPENDIX F SHORTCUT KEYS o AS IAS N 276 34 APPENDIX TABLE OF FIGURES cora ias 277 Page 5 Table of Contents Detailed Page 6 VENTSIM VISUAL VERSION 3 WHAT S NEW ccccccsssssssssssssccccssccccccccccsc
118. LL airways using that preset value For example if a model has 10 airways using a resistance preset called Rubber Flaps and the resistance for Rubber Flaps is changed in the preset box then ALL 10 airways using rubber flaps will have the new resistance applied when simulation is next performed Most items can be deleted by selecting the entire row or a selection of rows and pressing DELETE or by selecting and deleting individual values If a preset is currently in use a warning may appear stating the fact and the result it will have on the model Ideally presets should not be removed if they are currently in use The sort order of the preset values displayed in the spreadsheet and displayed in forms in other parts of the program can be specified All columns in the preset form can be sorted Ventsim Visual User Manual Page 118 11 2 1 Resistance by Ascending or Descending by clicking the column header once or twice For example resistances can be sorted by name by clicking the Resistance Name column header or by value by clicking the value header In addition row items can be manually sorted by selecting the row and pressing the UP or DOWN arrow on the keyboard The sort order will be retained next time the form is accessed and will be saved with the file 11 2 Accessing Presets Preset items are accessed from the main TOOL menu however most preset items can also be directly accessed from the EDIT for
119. Limit Combustion Efficiency The portion of fuel converted to heat defined under the Heat of Combustion of the fuel source Note The combustion efficiency of an underground fuel fire will generally be less than 100 Combustion efficiency generally depends on the availability of oxygen to all parts of the fire and the heat generated by the fire In many cases the efficiency may be a little as 75 or less although if this is not known using 100 is considered a more conservative approach Equivalence Ratio Shift The amount to shift the equivalence ratio towards or beyond the fuel rich gas generating zone Equivalence ratio is the ratio of available oxygen to the fuel burn rate to produce a perfect stoichiometric reaction An equivalent ratio of 1 would mean that there was exactly enough oxygen provided to perfectly burn a defined mass of fuel An equivalence ratio of less than one would mean that the amount of oxygen exceeds the rate at which the fuel consumes it oxygen rich fire An equivalence ratio of greater than one means that insufficient oxygen is available to burn the fuel mass resulting in incomplete combustion gases and pyrolised hydrocarbons fuel rich fire Note For perfect combustion in an ideal environment fires produce very little carbon monoxide where equivalent ratios are less than 0 5 The rate of carbon monoxide production increases as the equivalent ratio approaches 1 0 and the yield rate generally pea
120. Monoxide complicated by reversing and recirculating airflows Ventsim Visual User Manual Page 217 23 8 3 Choked and Alternating Airflows In addition if the fire occurs on a sloped airway the buoyance of the low density air can provide natural ventilation pressures that act against the normal airflow direction eventually slowing or even reversing the airflow Airflow reversal is shown on a graph as a negative airflow and the time at which it reverses can be determined by examining the point at which it crosses the zero airflow axis 2 ei ES S E a E FF OP YH EI ESO FF EOS SE d SK SK SS SS SS d a d af d di e g PO O BO RO E E E AE AE AS O O SSA A w vill A G tt w l A wl vi wo SM NA wt G t w l w i eh Time Second It is interesting to note however that if the fire consumes all available oxygen before airflow is reversed then the fire effectively becomes constrained by the lack of oxygen and heat output decreases which reduces the potential for natural ventilation buoyancy to reverse ventilation Even if airflow is temporarily reversed the reversed airflow which is already low in oxygen may not provide for enough fire heat output to continue reversed airflow and the airflow may switch backwards and forward between normal and reversed airflow In many cases equilibrium may be reached where the fire receives sufficient airflow oxygen to choke most airflow but not enough to provide the addit
121. Options Custom Resistance Controls the display of resistance icons where airways have been assigned a custom Display Threshold resistance Only airways with a resistance above the threshold will have an icon displayed Transparent Icons Shows transparent sides for icons over airways 12 3 6 Rendering Anti aliasing An advanced graphics option not supported by all graphics card which smooths the appearance of the edges of solids to give a visually more appealing look The option may significantly slow some graphics cards or cause graphics irregularities By default it is set to FALSE Backface Culling Hide Text While Rotating Rotation Inertia Damping Show All Arrow Node Text data Maximum Minimum Frame Hate 12 3 7 Size Airway Scale Size Data Node Airway Text Size Node Icons Arrows Size Node Icons Arrows 12 3 8 Text Figure 12 2 Graphics Setting Options Removes hidden surfaces from the display This may make older graphics cards more responsive in displaying complex graphics Hides text while model is rotated or zoomed Very large models with lots of text can slow or make smooth rotation movements unresponsive Use this option to hide text and make rotation movement much smoother Ventsim model rotation results in a short period of continued rotation after the mouse is released This is purely for visual appeal and is provided to give models the illusion of weight and solidity The speed a
122. Providing the icon is established with a PRESET name for example a resistance could be labeled in the preset list as a steel door a picture file can be dragged on to the icon externally from a Windows file windows or manager The picture file can be formatted as a jpg png or gif file In addition the GIF format also supports animated pictures which will be displayed as an animated icon in Ventsim Figure 30 1 Customised Truck Picture Ventsim Visual User Manual Page 264 30 2 1 Fans 30 2 2 Blocked Airway 30 2 3 Airway Resistance 30 2 4 Fixed Airway Fan icons are used to represent the presence of a fan Fans can be shown in four different colours Green normal operating fan Blue fan turned off and not operating Yellow fan operating in reverse Red fan stalled and air being forced backwards through fan Blocked icons indicate an airway blockage or very high resistance has been placed and air cannot travel freely through the airway Blocked resistance values are set in the preset menu If blocked resistance values are above the maximum resistance specified in the Settings then absolutely no airflow will be permitted along the airway Indicates the presence of an airway resistance above the normal airway resistance calculated from the size shape and wall friction factors An airway resistance normally represents an inputted resistance feature from the Edit Form which may be a door stopping or
123. S SNAPSHO TA a 90 9 2 EDT BOX ED IM IMIENUS da 90 9 2 1 SOECES AAA As 90 9 3 EDIT BOX A ODES MENU ee 91 9 3 1 Tools Set Fix Flow Resistance Orfflce E 92 9 3 2 Pressure SUIVEY TOO Sia AAA 92 9 3 3 APOY Gradient SIONE ti IO 92 9 3 4 DISTADUEE ROCK ADE ADA AAA 92 9 3 5 Convert Fixed Resistance to Friction Foctors oran conan conan nonannonen o corn nonnnoos 92 9 3 6 Convert Linear Resistance to Friction Foctors EE 92 9 4 AIRWAY TAB ease ee AAA ee 92 9 4 1 Airway Names Coordinates and Stage E 93 9 4 2 EE 93 9 4 3 PUEDO Sa as 95 9 4 4 EENEG ER 9 5 Eed 99 9 5 1 EE EE 102 9 5 2 Fans Stalled Low Pressure or Negoted EEN 102 O53 FON Press UNC GUN VC a EE eg 103 9 5 4 eer CU VE 103 933 FON FPOWCT CUVE ad 103 9 6 HEAT TAB ADVANCED EE 103 9 6 1 FRCOE ORG COON EE 104 9 6 2 BEIENEE 104 9 6 3 INCA EE 104 9 6 4 EES 105 9 6 5 ROCK COM ION EE 106 9 6 6 CONTONA orania a lion da od 108 9 6 7 Contaminant Options DyNQmMic cooococccnononononanonanonanonanonanonon oran nn 108 9 6 8 Sourcing Loca tonn E 109 9 7 INFORMATION E 110 9 7 1 Fanand Fed ONIL aia 110 9 7 2 Pressure normal eene 111 O73 HEREDA ati a 112 9 7 4 a RL dE 113 9 8 leg 113 9 8 1 SENSONS ee E EE 114 10 THE POPUP CONTEXT MUER 115 TO LL A O OA eee ea 115 102 LOOM OU EE 115 TOOLS NO EAN AAA AAA A 115 Page 9 101a Sele Leve A ai 115 TOPS SHOWA a oeae EEN 116 TOS VOW E E hee 116 IOF IS EE 11
124. ULATION ADVANCED la 178 18 1 VIEW DYNAMIC SIMULATION Reutte 178 18 2 CONTAMINANT BAANT U E da iii 179 18 3 FIXED LINEAR LOGARITHMIC RELEASE ssccessscescecessecsscecscceescccescecececsscecsscecsesecsscsesceceseecesuecssessesecsesecssecessesesseceues 180 18 4 DYNAMIC EXPLOSIVE CONTAMINATION EE 180 18 5 DYNAMIC GAS SIMULA ON dd ello ES 183 18 6 DYNAMIC DPM SIMULA TON ost is 183 18 7 D NAMICHEA FS M A TON ts ed ats eh a ah al 0h ig 0h Is td SN td A 183 MULTI GAS SIMULATION ADVANCED viii aia 185 19 1 INTRODUCTION Espais ui a LN TE IE ELO SM EU O NES OS eto el Eto ld 185 TO BL Ine Concentration Method ii 185 1912 Weco Me NOA EE 185 1913 Liner Emission Method SS EE a a O 186 19 2 el ITER e 187 T921 PIGEING GAS SUCESOS 187 19 22 EE 187 20 21 22 23 Page 12 19 3 DENSITY BASED SIMULATION OF D 188 THERMODYNAMIC SIMULATION ADVANCED csssssesssssscccccsscccessssssssccnscccccccesssscessnsscccenccccccccssssesessnssccccccsscess 189 20 1 INTRODUCTION Sta od dd dada 189 ZOT erg aaa 189 20 12 SOUC OF MOISES AS A E 190 20 2 APPLICATION OREA Va at id 190 20 2 1 Model Environmental SETAS ea 190 2022 SCP INDUS ee 190 E Senee A O O A dE 191 2024 Diesel Heat eege 191 P OA EE 191 DIODOS OXALA UON AAA AAA aida 191 202 LEARN lee 191 20 3 INJECTION OF MOISTURE ee 192 20 31 IIUSESUDDICSS ON ir a A E A A AAA A AO 192 20 32 Eer 192 20 3 3 Wet Material Dam Flooded oirwgys visssecscss
125. Ventsim Software Ventsim Visual Standard Advanced and Premium Versions Version 3 5 Ventsim Visual User Guide Ventsim Visual User Guide vrman Wont a Vee Madame Dn Leer Wins 14d A OHO sien Guertin Fis DURO D 0 ce eg Uu m Cuad 452205 3 E TPEADIOOK 5267 Volume 1 Version 3 5 The author and distributors have no liability to the licensee or any other person or entity for any damage or loss including special incidental or consequential damages caused by this product directly or indirectly The software is supplied as is without warranty of any kind either expressed or implied Warranties of merchantability or of fitness for any purpose are specifically disclaimed O Ventsim Software By Chasm Consulting PO BOX 1457 CAPALABA QLD AUSTRALIA 4157 admin ventsim com Page 3 Preface This manual presents a guide to the effective use of Ventsim Visual ventilation software for mine ventilation simulation and design lt does not profess to be a ventilation engineering guide and as such should not be used as a substitute for existing ventilation texts on underground ventilation and environmental engineering The manual may contain simplifications and does not attempt to explain many of the complex concepts and methods used in mine environmental engineering It is highly recommended that users of Ventsim Visual have at least a basic understanding of ventilation and simulation theory in o
126. Visual functions The toolbar will be slightly different between Ventsim Viewer Standard and Advanced versions Ile LOCH ET a E EES DI A DANI 060 6 9 OS 7 1 File Input and Output Functions JA a ull Creates a new file The current file will be cleared open the file dialog to load a new file UN P saves the existing file If no name has yet been set a Save File dialog will be displayed 7 2 Utility Functions la CTR Ex Stage 1 z 3e Reset the graphics card if the display becomes corrupted a Reverses the last action performed in Ventsim Visual G Cancels the previous Undo restoring any changes made Adds a new window to the display for multi windows viewing of the model Up to seven 7 windows may be opened L Automatically turns on all hidden airways to ensure all airways in the model can be seen Ventsim Visual User Manual Page 73 MEE Takes a static image of the screen in a form which may be saved copied or remain on the screen for further comparison with other windows Snapshot are static only and do not change 7 2 7 Find WW for specific items within a ventilation model Pressing the searchlight icon directly repeats the previous find action Pressing the submenu arrow next to the icon activates the find submenu as shown below Some examples include Name Find the name of an airway name or node Entering any part of the name will find airways containing the name part Nu
127. While most data values are self explanatory some notes below provide further explanation An airway with a fan fixed flow or fixed pressure will display the specific pressures power and cost of the fan or fix for the airway installation Unlike the Fan Tab the pressures and volumes displayed will be for the entire combined fan installation if more than one fan present not for individual fans Fan Present Ventsim Visual User Manual Page 110 Fan Pressure Fan pressures are derived directly from the pressure volume curve of the fan If the Fan Total Pressure FTP method is used the duty point will be simulated from the FTP fan curve and static pressure will be derived from the fan diameter or airway size For the Static Pressure FSP method the duty point is simulated from the FSP fan curve and the total pressure derived for the fan or airway size Special consideration is required for surface exhaust fans For an exhaust surface fan by definition the Mine Total Pressure loss of total pressure across all mine resistances at the collar inlet to the fan is equal to the required Fan Static Pressure FSP The Fan Total Pressure includes the velocity pressure loss of the fan to atmosphere The value provided by the simulation FTP considers evas and discharge area size but is theoretical and does not include shock or frictional losses between the fan collar and the fan discharge outlet As a result for an actual fan installation ad
128. XCEL Data ACCESS Data TEXT Data SQL Data MOVING DATA CEE Ese a Date From 01 01 1900 12 00 Bv E Filter Date To 31 12 2014 12 00 Ey E Filter Automatic Sensor m 7 Acti Update 10 l seconds V Activate Simulation Automatic Update Frequency Y Airflow Simulation Manual Y Gas Simulation 9 After Sensor Update Heat Simulation Set Interval Every A ce o 7 Log File Mini Dynamic SE Data Sources can be added to the LiveView connection list from the icons located on the RIGHT side of the list box SQL Database Many sensor systems use an SQL database system to collect and store sensor data Connection Ventsim Visual LiveView can directly connect and obtain sensor data from such systems Ventsim Visual User Manual Page 222 a Sol Data Source ls JO meza Status CONT MS SQL MYSQL Name SQL Data Server Myserver com au Select Database live Table LiveNonStandard User Name liveview Password gt E Use Windows Authentication Date Format Optional Big 1 e Enter an optional generic name describing your connection If no name is entered the connection server name will be displayed in the connection list instead e Enter the Server web or IP address location the name of the database and the name of the Table View or Query which contains the sensor data e If Windows authentication is not enabled on the database a valid user name and
129. a 6 1 1 Scale TOO rita iii 71 THE ACTION TOOLBA Rosina ns 73 7 1 FILE NPUT AND OUTPUT FUNCTIONS tots A adi 73 7 1 1 IOV a 73 7 1 2 EE 73 7 1 3 EE 73 7 2 UTILITY Sen ue KE 73 7 2 1 eeben 73 2 2 2 CPI e 73 7 2 3 PP E tes E EE EAEE A E E ENEA E ET 73 7 2 4 Create New WINKOW ccccccccsesssceceesscccccsssscecssssscccessssecessesecesssesecesssssesessssceeesssscesesssseeseassseeseasesens 73 7 2 5 te 73 7 2 6 Ster 73 7 2 7 EE 74 7 2 8 Ee EE 74 7 2 9 POr DEC IVE VIV ee 75 1210 FOW ANMOUON EE 76 Lale Ee e 77 23 ein dl leg GR le EE 77 7 3 1 VA occu ooo o oo o ene 77 7 3 2 e EE 78 7 3 3 EE 80 7 3 4 BE CE ase esa iii cirio 80 7 3 9 Multi Select OP OWS rias ooo 80 7 3 6 A A 80 7 3 7 Ee 81 7 3 8 2 SSA 81 7 3 9 MOVE E 81 SO COPY meda 82 EC D MR A a a a a a a a a 82 e USE e 82 TAL CONTAMINA N Ea o ass 82 PAA MONTOS AS 83 RS E A A A A 83 7 4 SIMULA TON FUNCION ai 83 7 4 1 edel SIMMUIOHON Said 83 7 4 2 Heat Simulation ADVANCED aaa 83 7 4 3 CONTAMINANT Simulation BEE 83 7 4 4 Recirculation ADVANCED 0 ccoscesesscesosssesesecesosesesosssesosesesessesosssesssssesnssessesescussesoussesueseseseses 85 7 4 5 Financial Simulation ADVANCED css cccsesssesessceeesscesesscesesscesssscesssscesnsceceuecessuecesuscesnsseseneees 85 8 THE DATA TOOLBAR E 86 8 1 1 DOTA CAMEO a 86 8 1 2 AMG EEN 86 8 1 3 Dypamie Text e 87 8 1 4 s 87 8 1 5 ISI edi 88 9 FEEF 90 9 1 A E AENT 90 9 1 1 PIC
130. a joining node It effectively splits and joins both airways into new airways Imported DXF file commonly have lines which cross the path of another airway but do not have a joining node Searches for airways which have duplicates in the same or similar position Duplicate airways can cause problems with air simulation due to poorly defined or hidden flow paths that the user cannot see a Filtering GK co Il x Duplicate Parameters 5 S Adjacent Angle 20 ju Adjacent Distance zero for auto Find Action J Exact Select J Reversed Highlight 7 Similar Overlapping Delete j Duplicates Figure 5 17 Duplicate Finding Tools Adjacent Angle is the maximum angle difference between adjacent airways that may be considered as a duplicate Airways next to each other with greater angles between them Ventsim Visual User Manual Page 63 5 7 7 Convert To 3D 5 7 1 Utilities will not be considered as a duplicate The smaller the angle in degrees the more parallel and airway must be to be considered a duplicate Adjacent Distance is the maximum distance two adjacent airways can be apart over which they will no longer be considered as duplicates Exact selects only an exact matching airway as a duplicate Reversed selects airway the same but facing opposite directions Similar selects airways similar but not identical The adjacent angle and distance will be used as a criterion for selection Action defines what actio
131. aced in a model per unit of engine power used Ventsim Visual User Manual Page 148 For example a 200kW rated diesel engine will consume nearly 600kW in diesel fuel energy initially rejecting 400kW of waste heat through engine friction and exhaust In most cases the remaining 200kW of mechanical power will also be converted to heat through further friction losses except where the mechanical power may be partially passed to other energy absorbing processes such as water or transfer of rock uphill If required this can be accounted for under the potential energy conversion item Utilization Diesel engines underground rarely operate at full power 100 of the time It is important to consider the actual weighted percentage of time engines are operated at full power to gain the true heat input into the mine model For example a load haul dump unit LHD operates continuously but uses only full power 100 while loading buckets and hauling up a ramp for 15 minutes per hour operates at 50 maximum power tramming horizontally or downhill for 30 minutes per hour and idles at 10 maximum power for the remaining 15 minutes per hour 15 x 100 30x50 15 x 10 60 52 5 peak utilisation Potential Energy In some processes diesel mechanical engine power can be converted into other useful Converson energies For example a truck hauling rock up a decline will impart a portion of its 13 1 4 Diesel Fuel mechanical energy into the potent
132. ach all parts of the drive and remove the fume The intial blast gas concentration mixing into the atmosphere is automatically calculated by Ventsim and is based on the blast size and the dispersion factor This value is shown as an estimate in the EDIT box Results for Version3 0 in most cases should be similar to Ventsim 2 0 however for large blasts initial gas concentrations may be higher than determined by the user and clearance times may be shorter Ventsim uses logarithmic decay series to determine the portion of injection of blast gases into the atmosphere The decay series uses a dispersion factor of between O and 10 to control the logarithmic decay rate The dispersion factor is a unitless number that uses a square power series to describe the rate of gas removal For example a factor of 2 will initially release the explosive gases into the atmosphere at twice the rate of a factor of 1 A factor of 4 will initially release the explosive gases at twice the rate of 2 creating an intially more toxic atmosphere but clearing more rapidly These o factors are somewhat subjective DN SS JEJE METETE SE JEJE TOTES E a a o o E a a E kd E g o po i ge a e e E A A e EREE a A Ventsim describes 1 as very slow FEF MONOS i e e e e SETAS dispersion and very fast as 10 Tr daai and it is suggested that mine use D a gas detection meter to gain an understanding of thei
133. age 51 5 5 Run Menu The RUN menu allows menu access to the main simulation functions of Ventsim Visual Standard Functions e Airflows e Steady State Contaminants Ventsim Visual Advanced Functions e Thermodynamic e Diesel Particulates e Dynamic Contaminants Gas Heat and DPM e Recirculation e Financial Ventsim Visual Premium VentFIRE Functions e VentFIRE Fire Simulation e Multi type dynamic simulations 5 5 1 Airflows ALL Undertakes a steady state airflow simulation of the model The Standard version will only perform an incompressible flow simulation whereas the Advanced and Premium versions will optionally perform compressible flow mass balanced simulation if selected in the settings 5 5 2 Thermo dynamics Undertakes a steady state thermodynamic simulation which derives initial airflow and ADVANCED mass flows from an airflow simulation Thermodynamic simulation is complex and endeavours to simulate numerous parameters encountered in a mining environment The simulation process follows well documented methods described in books such as Subsurface Ventilation and Environmental Engineering by Malcolm McPherson Heat parameters that Ventsim Visual Advanced considers includes e Heat and moisture derived from rock strata and ground water e Thermal properties of different rock types e Heat from point sources such as electric motors linear sources such as conveyors diesel engines and oxi
134. age will have mostly shared airways with the exception of airways containing the changed heat gas or contaminant parameters In this case these airways Ventsim Visual User Manual Page 205 are made into a unique copy for the required stage using the EDIT box AUTO COPY button and the parameters are changes accordingly The stage names can be changed to descriptively describe the changed parameters and the stage description available from the TOOLS gt STAGES menu can contain more information if required Ventsim Visual User Manual Page 206 23 1 1 Example 1 23 1 2 Example 2 23 VENTFIRE Scenario Simulation Premium 23 1 What is VentFIRE VentFIRE is a module that uses dynamic simulation techniques time based to simultaneously model heat gas and airflow changes on a mine environment over a period of time While the heat source could be a fire VentFIRE is also designed to work on other heat or cooling sources such as for example diesel machines and refrigeration plants In addition VentFIRE allows a ventilation model to be dynamically modified during simulation for example doors may be opened or closed or fans may be turned on or off at certain times The result is that a complete scenario may be modelled over a period of time and the atmospheric changes observed at different points in the mine It is necessary to model the results of a large truck fire in the main decline in particular the sp
135. airway using a surface connected airway to represent an external gas source see the Gas Simulation section for further information on this method 17 2 Contaminant Steady State Performs a steady state continuous contaminant simulation based on the position of contaminant source s placed in the model Steady state simulation simulates the spread of contaminants until such time as the contaminant spreads through all possible pathways and contaminant levels have stabilised to a steady state Where recirculation may be present the simulation will continue until the recirculated air has reached equilibrium concentration The simulation will only show result when steady state conditions have been achieved Ventsim Visual User Manual Page 174 Upon completion the view will switch to a contaminant view of the final results with airways coloured according to concentration of contaminants The contaminant spread time can also be selected as a colour or data text option however this function will only provide the time that the contaminant first reaches an airway location not the specific concentration of contaminant at that time For calculating contaminant concentration at a particular time the Dynamic Simulation function will need to be used Contaminant can be placed in a model by using the Edit toolbar function and selecting the Contaminant Tab or the Contaminant toolbar button Contaminant strengths are volume unit based and
136. airways it is generally small due to the limited heat energy flow able to be carried by these low flow airways The ratio of output refrigeration power KWR generated by the refrigeration heat exchange process versus the input electrical power KW required to produce this heat exchange This factor is not used by the simulation by rather by the power and cost calculation of a model in the Summary section Sets the temperature balance limit Ventsim Visual must achieve for all airway mixing at junctions in a model to consider a simulation as balanced If the balance is not achieved for EVERY airway and junction iteration is performed until the iteration limit is reached or temperatures are resolved HINT The smaller the temperature accuracy set the longer a simulation may take to complete In most cases the vast majority of airways will fall well under this limit and any temperature accuracy issues will be limited by very low flowing airways which have little impact on the main model Limits the amount of heat that can be put into a single airway This is mainly included as a check to ensure excessive heat is not placed in an airway such as a point heat source value accidently being entered as a linear heat value The number of recirculated airways beyond which Ventsim will first ask permission to simulate exact recirculation amounts The simulation routine to calculate individual airway recirculation is complex and time consuming If
137. airways or in airways leading to or from blocked airways This will create a simulation error as airflow will be unable to travel through the blocked airway without unreasonable pressure or heat build up Figure 7 9 An airway stopping 7 3 9 Move Moves the selected airway airways airway ends or icons to a new location by clicking and dragging the LEFT MOUSE BUTTON Unless the SHIFT key is held the move will always be done at the same horizontal elevation A true vertical line is displayed showing where the move point is in relation to other airways e TO move an airway end and all other attached airway ends c ickon of close to the end node of an airway e TO move an airway end away from other airways click slightly back from the airway end node The airway should break away from other connected airways e TO move an entire airway both ends first select the airway with the select button or fence the airway to be moved and then drag the selected airway s to the new location e Multiple airways can be moved by first se ecting the airways and the dragging any one of the selected airways to the new location e TO move an icon such as a fan heat source or resistance along an airway simply grab the icon with the left mouse button and drag the icon along the airway to the new location Icons can also be dragged to other airways Ventsim Visual User Manual Page 81 Left Mouse Click Opens the coordinate entry
138. al Page 229 d Vertsim Visual 3 ConnectorTestvsm z D ot View Sawedvwess Run Connect Took Settings PeGo SE 6 AO ses T cas gt e 5 6 Bache a k g O The sensor data boxes can be shown or hidden by selecting the Text Display Icon and hiding k Loa Help EPIA FA AT ARS z 2 off y the Ventlog LiveView text display option 24 6 COPYING LIVEVIEW CONNECTIONS TO ANOTHER MODEL FILE w w w w Data Value Airway Names Node Names Grid Values Live Ventlog All On All Off To copy your LiveView connections and settings to another file load the other file in Ventsim the use the FILE gt INHERIT function contains the LiveView settings choose the LIVEVIEW option in the Inherit setting box then click OK The LiveView connections and settings will now be available in the new file Ventsim Visual User Manual Page 230 Select the Ventsim model file that 25 1 1 Radon Concentration 25 1 2 Radon Progeny 29 RADON SIMULATION Premium Radon simulation is a separate type of simulation that differs from normal gas simulation in that the hazardous nature of the gas is not directly the concentration of radon in the airways but radiation exposure from the radioactive decay of the gas into the various radon daughter elements 25 1 Introduction Radon gas can emitted from many types of rock While usually associated in high
139. al User Manual Page 83 Reverse Contaminant Find Source Clear Contaminants Figure 7 11 Contaminant Options Contaminant Spreads contaminant sources through the model as a never ending continuous stream steady state The display and colour legend automatically switch to a contaminated concentration display showing the simulated spread and contamination of the contaminants See Contaminant Spread from the menu bar section for further information Hint Anumber of additional contaminant data types are available including the spread time of data Diesel DPM Advanced Performs a diesel particulate matter spread simulation based on diesel heat sources in a mine model The result is displayed as a concentration per unit volume of airflow The diesel heat sources are defined under the thermodynamic Heat Tab from the Edit Box form Diesel heat sources are converted to a diesel particulate emission rate per unit of engine power based on either a default setting a preset heat source setting or entered directly in the Edit Box or Preset form Diesel emissions are spread throughout the model using a steady state complete mixing algorithm that assumes perfect mixing and no settling or deposition of particles Diesel sources are assumed cumulative and downstream sources or recirculation may increase concentration higher that the initial source The simulated air concentrations are given in the same emission type as specified in the ex
140. and enters this value in the Heat Presets The five 5 loaders are then placed in typical airways around the mine and the DPM SIMULATION function is activated Speotic Heat IC Rect Deag Wetness fraction 0 13 Fixed Data Age Envy Ex Rock Temperature Moure 00 pum Ar Temp WGO Cuxtisatios 00 Wim Diesel Empaen 0 00 en Figure 21 2 Diesel heat and DPM source placed in airway The DPM levels can be actively viewed around the mine and the colour ranges adjusted in the Display Manager to view areas of potential concern Further changes or increases to air flows will require a re simulation of the diesel particulates to recalculate new values Ventsim Visual User Manual Page 198 Figure 21 3 Example showing DPM simulation colouring through mine Ventsim Visual User Manual Page 199 22 STAGING All Versions EI CITT aa 22 1 What is Staging Staging is a term representing the ability of Ventsim to create multiple versions of similar models in a single simulation file Examples of this may include creating ventilation models representing different phases or timelines of the mine design or alternatively it could be used for representing different options and variations for a ventilation design Up to 12 different stages can be developed in a single model Each stage can share common airways with other stages or can have unique airways that are only valid for a particular stage o
141. ange can be changed from the Settings menu Display all elevation ranges This function will reset any levels selected from the previous function Enter the view mode See toolbar view for more information Enter the selection mode Airways selected can be deleted edited moved or copied See toolbar selection for more information Ventsim Visual User Manual Page 116 10 1 8 10 1 9 10 1 10 10 1 11 10 1 12 10 1 13 10 1 14 10 1 15 Add Edit Block Delete Move Reverse Action Data and View Toolbar Reset Display Enter the airway construction mode Airways can be drawn by dragging the mouse or edited by clicking the mouse See toolbar add for more information Enter the airway edit mode Airways clicked or fenced can be edited in the Edit box See toolbar edit for more information Enter the airway block mode Airways clicked can be blocked or unblocked to prevent or allow airflow See toolbar block for more information Enter the airway delete mode Airway clicked or fence selected and clicked are deleted from the model See toolbar delete for more information Enter the airway move mode Airways clicked can be moved via coordinates Airways dragged can be moved with the mouse See toolbar move for more information Enter the reverse airway mode Airways clicked are reversed along with any fixed flows pressures or fans See toolbar reverse for further information The toolbars a
142. ans running reversed Total fan power Fans running with no or negative pressure added Fans running in reverse user selected Total of all fan electrical power The is calculated from fan shaft efficiencies and motor efficiencies The fan power is calculate from the fan power curve If the curve is unavailable it is estimated from 3607 6 kW the fan total efficiency curve If this is unavailable the default fan efficiency is used HEAT amp MOISTURE INPUT SUMMARY Ventsim Visual User Manual Page 55 Diesel Sources Sensible Heat Sources Linear S Heat Sources Latent Heat Sources Oxidisation Sources 0 0 kW sources 0 0 kW sources 0 0 kW sources 0 0 kW sources 0 0 kW sources Sources of diesel heat and contaminants Sources of sensible dry heat Sources of heat distributed along multiple alrways Sources of latent vapour heat Sources of oxidising heat Electrical Heat Sources 3609 2 kW Sources of electrical heat Total Input Heat Total Strata Heat Broken Rock Heat 3609 2 kW 2885 1 kW 1450 kW Total heat input from man made influences Total heat input from heat dissipated from rock Total heat from broken rock which is calculated when an advance rate is entered for airways or stopes TOTAL HEAT SUMMARY 6494 3 kW Summation of all heat Total Refrigeration 0 0 KWR Sources from O Refrigeration installations HEAT BALANCE TOTAL
143. anteed to protect workers the mine will need to consider implementing engineering strategies such as increased ventilation flow or improved engine or emission control Where increase ventilation flows are used ensure that this has a cost benefit against improve exhaust emission or exposure control The financial functions in Ventsim Visual provide useful feedback on the additional cost of ventilation cost which may be better invested in exhaust emission reduction 21 2 How to perform DPM Simulation in Ventsim Ventsim Visual uses the diesel equipment placed for heat simulation to also simulate DPM concentrations Emission rates can be entered either in the Heat Presets or directly as a manual entry in the EDIT form Once again note that the atmospheric concentration will be given in the same composition units as the diesel emission assumption emissions rates are entered as elemental total carbon or total particulate matter therefore atmospheric concentrations will be of the same type A diesel engine is listed as having a PM particulate matter value of 0 16 g kW hr The mine is regulated under an Elemental Carbon limit of 100 ug m3 and the user has assumed that Elemental Carbon is 50 of Particulate Matter PM Therefore the user must either convert the diesel emission rate to elemental carbon 50 0 08g kw hr or keep in mind that their actual simulated atmospheric limit is in total PM 200ug m3 instead of Elemental Carbon EC
144. arge models where different areas can be quickly returned to for viewing simulation results Save Quick View Creates a temporary view position for a model The view is added sequentially to previous stored Quick Views The sequence of stored quick view can be recalled or returned to using the LEFT and RIGHT arrow keys Clear Current Clears and removed the currently recalled quick view The view is removed from the sequence of other stored Quick Views and can no longer be recalled Clear ALL Clears all Quick Views from memory Previous Quick View Recall the previous Quick View from the sequence of saved Quick Views Next Quick View Recalls the next Quick View in the sequence of saved Quick Views Copy to clipboard Copies the screen to the Windows clipboard for direct pasting into an external documents such as a Power Point presentation Static Views are primarily for referencing areas before and after simulation Copy to clipboard Similar to above but copies any overlying windows such as legends and graphs all Copy to clipboard Similar to above but copies an ultra high resolution picture to the clipboard This picture HI RES Snapshot has more detail than the screen graphics but may fail to work on slower or older computers Hi Res pictures will show more clearly in large format printing or reports but are of less use in screen or projector presentations where the screen cannot show the higher resolutions Create
145. arrow at the right In normal free draw mode airways that are constructed from other airways will adopt the attributes of the joined airway such as size and wall friction factors types Airways that are NOT constructed starting from other airways will adopt the default set in the Settings menu Left Mouse Click Edit the airway Left clicking the mouse on top of an airway will show the Edit Box for that airway Left Mouse Drag Constructs a new airway from where the mouse is initially pressed to the point where the mouse button is released To manually control the coordinates of the airway being constructed select the sub menu functions of the add button as shown below Draw Single Draw Continuous Draw Gradient Draw Coordinates Construct Duct Construct Ramp Convert Centreline Convert Any Measure Figure 7 4 Manual airway drawing options Draw Single Allows the mouse to draw both ends of a single airway Airways can be drawn vertically by hold the SHIFT key down Draw Continuous Allows the mouse to continuously draw joined airways until either the ESCAPE button is pressed or the airway joins into another airway Airways can be drawn vertically by hold the SHIFT key down Draw Gradient Allows the mouse to continuously draw joined airways at a predefined gradient until either the ESCAPE button is pressed or the airway joins into another airway The defined gradient is request when activating the function and can be
146. ate to another but instead returns values as sensible and an evaporated moisture flow estimate This may be useful for calculating moisture being evaporated from underground processes such as decline dust suppression sprays drill machine activity or evaporative cooling chambers 13 1 3 Diesel Engine Diesel engine heat loads can be more accurately calculated by considering the environment and utilisation of the diesel engine within the model The diesel engine calculator assists with this The output of the calculator is return as an averaged diesel engine output The corresponding sensible and latent heats are also provided as a reference however are not transferred to the model as Ventsim Visual automatically calculates these values in the model from the diesel power value Heat Assistant erm So Air 1 Air 2 Diesel Eng Diesel Fuel Water Chill Engine Input Data Max Rated Engine Power kW Diesel Efficiency p35 Peak Utilisation 50 Potential Energy Conversion 0 Estimated Diesel Heat How Diesel Engine 125 0 kW Sensible Heat 229 5 kW Latent Heat 127 6kW Figure 13 3 Diesel Heat Estimator Diesel Efficiency The percentage of diesel calorific energy converted into mechanical energy This diesel efficiency is an estimated value for a typical diesel engine and generally should not be changed unless specifically known for a type of engine or particular type of fuel The value dictates the amount of heat pl
147. ation of Gas Ventsim Visual Advanced has the ability to simulate the effect of different air densities on airway resistance and natural ventilation pressures This ability is extended to include the effect of gas composition on total air density and natural ventilation pressures To use this option the following options need to be enabled in the Settings gt Simulation gt Gas a Compressible Airflows available from Settings gt Simulation gt Airflow Menu b Natural Ventilation Pressure available from Settings gt Simulation gt Airflow Menu c Gas Density for Simulation available from the Settings gt Simulation gt GAS Menu Once enabled provided Natural Ventilation Pressure NVP option is chosen any gas distribution simulated in the model will result in changes to airflow simulation based on the effect of the gas density on air buoyancy and the change in effective airway resistance For example if 5 methane is simulated through an area of a mine with a Gas Simulation then providing the Gas Density Simulation option is turned on subsequent airflow simulation will predict the steady state buoyancy effect of methane through that region of the mine Another option may be to simulate gas drainage through pipe models although this process has yet to be validated in Ventsim Visual Warning After completing simulation work using Gas Density simulation options remember to restore the settings and turn off the option ot
148. ault simulated airflows are not updated when changing Stages Therefore airways that are shared with other stages may contain data belonging to simulations from other stages unless a new simulation is performed for the current stage ad Stage List In Use ae Stage Name Preliminary Pre Production Production Description 22 2 2 Selecting Stages Stages can be selected from the main stage combo menu Once a stage is selected ONLY airways that are assigned to that stage are shown on the screen All other airways not belonging to the selected stage will be hidden and will not form part of the error checking simulation or summary Ventsim Visual User Manual Page 202 22 2 3 Assigning airways to different stages O Initial Development Preliminary Pre Production Production You cannot view ALL airways on ALL stages simultaneously and at this time to prevent confusion all Windows opened in Ventsim will display only the selected stage Airways can be assigned to different stages from the EDIT box function Simply use the SELECT button to select the airways then use the EDIT button to change one or more airways to a new stage selection File Select Airways Tools Airway Fans Heat Contaminant Gas Dynamic Sensors Info Notes Name j a ndex 363 Pre Production T Unique 4513 Stage CR Enty 70L 673 1 565 9 17878 15662 ES we A horizontal series o
149. ault airway Primary Secondary Layer Default view layers to set to new airways Reversing Default Default resistance to apply if resistances are set in airways which have reversed airflow AND Resistance the restrict reverse airflow button is pressure This is only applied if no reversing resistance already exists for the preset item For example a resistance for a door may be 10 during normal flow direction but may reduce to 0 5 when the airflow is reversed and the door Swings open Once again this figure is ONLY applied if the restrict reverse airflow option is chosen in the EDIT box AND there are no pre existing reversing resistances set in the resistance preset spreadsheet Default layers to apply for new airways Ventsim Visual User Manual Page 124 Layers Primary and Secondary Size Width Size Height Default size of new airways Imported DXF and text files without specific airway size will Size Area also be set to these values Hint Airway defaults are normally only applied if airways are constructed without connection to other airways Where airways are connected to existing airways they will INHERIT the settings of the airways the new airways is connected to This behaviour can be modified from the EDIT gt NEW AIRWAYS menu item 12 2 2 File Settings Auto Backup Forces Ventsim to make a backup of the currently worked model every 5 minutes If the program crashes or is forcibly exited the backed up model
150. ay have substantially different psychrometric properties than air that was universally cooled While the two airflow cases will report similar heat reduction consisting of sigma heat and enthalpy flow the partially chilled airflow case may have the refrigerated portion chilled to much lower temperatures resulting in an increase in condensation and subsequent removal of additional moisture The resulting mixed stream will then be generally warmer but dryer with a lower relative humidity compared to the stream which is evenly chilled Whether the installation is on surface or underground if a cooling device only chills part of the airflow ensure a separate airway is included to represent this chilled portion The example below shows the substantial difference in downstream temperatures between the two cases N A a Index x o eg 5 di Pedne E entsim De penstration Network ee Unique 10 Heat Sensible 0 0 kW Thermal Conductivity 2 00 Wim Heat Latent 0 0 Kw C Thermal Diffusivity 1 500 m2is l Heat and Cooling Rock Conditions F Refrigeration 3500 0 kW Specific Hea d 790 0 We Diesel Engine 0 0 kW Diesel Emission 0 000 g kW h c Rock Donaty es kg Oxidisation Doo e Wetness Fraction Mee Linear Heat CH io Age or Year Entry 5 00 year Moisture Point milsec ee SO Moisture Linear 0 0 g sim Node Name 6 Elevation 950 0 m 9250 m E Wet Bulb 20 3 143 0 M40 Decli Dry Bulb
151. ays Select Primary Secondary and Air Type options on the Select Box Select Edit gt Copy Attributes Click the airway you wish to copy the attributes from Select Edit gt Paste Attributes Click or Fence the airways you wish to copy the attributes to 5 2 5 New Airways Control which attributes are applied to new airways Use Inherited New airways drawn from existing airways will inherit the settings from the airways they are attached to such as size shape friction factors etc Airways which do not originate from another airway will use the default setting values Use Defaults To force the program to use the Default Values from the Settings Menu choose Default All new airways drawn regardless of whether they connect from existing airways will use the default settings Use Cloned Forces the program to use the Cloned Settings from a previously cloned airway For example if a shaft is to be drawn from a horizontal airway cloning a similar shaft and then drawing the new airway with this function set will result in a new shaft with the same size parameters and layer settings as the cloned shaft 5 2 6 Find Find Next Automatically locates specific airways and moves the screen to selected parts of a model Find ALL Ventsim Visual User Manual Page 47 5 2 7 5 3 1 5 3 2 5 3 3 HE Ventsim Visual Text Det l SCH File Edit View SavedViews Run Tools Window Help JU sie v Quantity P Fd gl Redo
152. bar functions e Import airway data from a formatted spreadsheet using the TXT import function Import graphics data from a DXF DWG Datamine Surpac graphics file into Ventsim and convert the data to airways Most mine planning and CAD packages will have the ability to export data to one of these formats Regardless of the method used in summary the recommended steps for constructing a ventilation model are as follows 1 Construct the airways either manually using the DRAW function or via the IMPORT function ensuring all airways join correctly to each other Filter tools are available in Ventsim to assist with ensuring airways are joined together 2 Use the EDIT button to edit the airways that connect to the surface and mark SURFACE option on the form 3 Again using the EDIT button set the correct size and shape for all airways Insert any ventilation controls or regulators in the model and specify airway characteristics such as friction factors and shock losses 4 Place a FAN or FIXED flow in an airway again using the EDIT button and selecting the FAN tab of this form This will provide pressure to drive the airflow through the model 5 Finally press the SIMULATE button to show the result of the model construction If everything has been constructed correctly the airflow data and arrows should show the result of the simulation 6 If some airways are dead ends then simulation warnings can be prevented by setting the
153. be designed to perform better in reverse than others These figures ideally need to be derived experimentally be measuring actual fan performance with blades running in reverse Ventsim Visual initially defaults to 0 5 for both 50 of maximum pressure and 50 of maximum airflow The method used to estimate curve data between specified fan duty points The cubic spline method estimates a curved data path between fan points If only a few points of data are available this may produce a better estimate of fan duty however the method may be limited by sudden changes in curve data point direction Ensure sufficient points are available to produce a smooth non reversing curve The linear method predicts a straight path between points This method is slightly faster during simulation and if the maximum number of fan points 10 are entered it should provide sufficient accuracy in most cases HINT It is important that pressure on the curve is not permitted to bend over in a U shape or upside down U otherwise the simulation may oscillate between two pressure points Stall regions of fans should be omitted for this reason Comment box is included to describe more information about the setup or configuration of the fan It is not used for simulation Fan Point Table The table will allow direct entry of fan curve data Fan curves will be constructed as data is entered Points can be submitted non sequentially and will be automatically rearran
154. be pulled back into any current window by selecting the saved name from the pull down view list Deletes the saved view stored in the CURRENT pull down menu list and hence removes this name from the list Four view orientations are set as defaults e PLAN e EW SECTION e NS SECTION e ISO These standard views will display the model at various orientations although the model can still be orientated to the same orientations by using the RIGHT mouse button These views cannot be deleted or changed Caution The Perspective view will distort some aspect of the views For example the plan view will show the airways at the EDIT grid level to plan but airways above and below this elevation will appear larger and smaller respectively Any further saved views will be placed below these items Saved views save the position orientation colour scheme data types and attributes of the screen at the time at which they were saved Ventsim Visual User Manual Page 50 Hint Saved views are not only useful for recalling the location and orientation of a model Because they recall selected levels layers data types and colours they can be a quick way to establish a template to edit and view different data aspects of your model For example you may have an AIRFLOW view custom set to highlight a certain range of airflows in different colours while a HEAT view may be saved to highlight a range of temperatures Ventsim Visual User Manual P
155. ble working level concentration of 100 pCi litre although this level has been substantially reduced since it was devised The harmful effects of Radon progeny are generated by exposure over time The current method of assessing mine worker dosage is based on time weighted cumulative exposure to Radon progeny For example an exposure to one 1 Working Level WL for one 1 working month consisting of 170 hours equals 1 WLM cumulative exposure A typical recommended limit for a standard year of 2040 hours exposure is 4WLM which would be equivalent to continuous at work exposure of 0 33WL An alternative SI exposure level unit is mSv which can be calculated by the uJh m3 progeny level where 1 hour exposure at 1uJ m3 equals 0 00141 mSv Therefore an annual exposure of 2040 hours at 10uJ m3 would be a dosage of 28 8 mSv A typical recommended limit is 20mSv for a standard 2040hr year which is equivalent to continuous at work exposure of 6 9 uJ m3 Standards may also exist for higher short term exposures Ventsim also provides an annual exposure dosage calculation however it must be remembered that actual exposure and dosage will be the weighted average of all regions of the mine accessed by a mine worker and this calculation is based on 2040 work exposure hours per year which may need to be adjusted for different rosters or time spent in the mine to give actual individual dosage estimates 25 2 Using the Radon Simulation Feature Four 4
156. by clicked the airway with the Edit Form and selecting the Notes Tab sf A Indicates an airway is connected to the surface Surface airways can draw or discharge mine airflow to or from the atmosphere Defines the end of an airway in construction that has neither been flagged as a surface connection or a closed dead end Headings with these symbols may raise a warning during simulation and will be assumed to be a dead end 30 2 15 Orifice A Ventsim Visual User Manual Page 267 30 2 13 Surface Connected Airway 30 2 14 Unknown Airway End 30 2 16 Backfill 30 2 17 Obstruction 30 2 18 Sensor 30 2 1 Shock Loss Indicates an orifice restriction is present in the airway Orifices indicate smaller opening in a wall such as a regulator and may be used to apply additional resistance to an airway Indicates the presence of backfill in an airway Backfill will obstruct the airflow by narrowing the airway passage In addition backfill will insulate a portion of heat transfer into the airflow from the surround rock strata during heat simulation Indicates an obstruction is present in the airway Obstructions reduce the area of the airway for the length of the airway They can be used to simulate pipes compartments or structures that limit the airflow cross sectional area available Indicates the presence of one or more sensors in an airway A sensor can feed an external data source into a Ventsim model
157. can be entered either as a proportional unit base or a volumetric gas concentration EXAMPLE Entering 100 as a concentration value may indicate 100 of the original contaminated source strength in an airway and will result in the dilution of the value as uncontaminated air is mixed downstream In this case a downstream value of 25 downstream would indicate 25 of the original contamination strength Another example of entering 2000 may indicate an initial value of 2000 ppm of CO gas Downstream values would show diluted concentrations of this value The units name does not need to be changed however if desired can be changed in the Settings gt Contaminant menu E EOI Line SES File Select Airways Tools Airway Fans Heat Contaminant Gas Dynamic Sensors Info Notes ON sor Activate Contaminant Contaminant Contaminant Concentration 0 CO ppm The contaminants may be cleared by pressing the C ear button at the base of the contaminant sub menu 17 3 DPM Simulates a steady state flow of diesel particulates calculated from diesel heat sources placed in the mine For further information on this function see the DPM simulation section 17 4 Gas Simulates a steady state flow of multiple gases defined as sources in one or more airways This is similar to contaminant simulation but volumetrically simulates many different types of gases simulataneously For further information on this function see the GAS simu
158. cases that a smaller portion of the contaminant will arrive at an airway location ahead of the predicted time Source Mix The portion of a contamination that has tranvelled along upstream airways to the location of the set contaminant The value is a ratio of the airflow that contributes to the total volume of air flowing through the contaminant source airway Sourcing Tool The category of air simulated in the sourcing tools simulator The sourcing tool simulates fresh air contaminated air and potential source of contaminated air Diesel Particulate Matter Weight per unit volume of diesel particulate matter in a volume of air Ventsim Visual User Manual Page 262 Recirculation Recirculation Stream 29 1 9 Rock Properties Conductivity Density Specifc Heat Wetness Fraction Age Thermal Diffusivity VRT 29 1 10 Measured 29 1 11 Gas The portion of air that has recirculated through the airway The maximum portion of air that has recirculated through any single airway upstream from the airway This may assist in determining the quality of air travelling through an airway if it has undergone recirculation at some point upstream from the airway Thermal conductivity of rock in the airway Density of rock in the airway The specific heat of rock in the airway The fraction of wet to dry surface of the rock in the airway A fraction of one 1 represent fully wet while zero is dry The age of the rock since exposed by
159. ccccccessseeeess 207 23 1 VV HATS VENTE Eege 207 LL DANDE Re OR Pie DEAS PPP A AA TTP ATI OTE ORE POPOL ERT OT CORES NTI DTT 207 E IN el TE 207 Ge A 0 LO A A E CL OO iii ths es cuts he kde ae ssl thins NOS 208 23 2 PREAMBLE ON FIRE HEH Ee 208 23 3 ele ger 208 23 4 USE THE VENTFIRE FUNCTION EE 209 E AJJI EV EE 209 2342 Addino MOITOS a AAA 211 23 5 ESTABLISHING SIMUIATION PARAMETER Seoitiosciostin irnos ii 211 239 1 Pynarie SIMUIGUON E ge CN 211 233d O Ee 212 LDL ROSS as 212 2a a EE 212 23 54 Preset Combustible EN 213 239 1 ere 0181 90 AP A E a a ase cae aa atari 213 23 6 SIMUWATING EVENTS dista 213 236 EASP SONO A a o a 213 230 2 Before Each MUITO ada 214 23 6 3 Running a VentFIRE FireSim Simulations En 214 2304 Mat SIMIO A AS A cada 215 24 25 26 27 28 Page 13 236 5 EXPIOSIVE SITUATION dd 215 23 6 6 Program limitations during simulation En 215 23 7 VIEWING EE 216 DIF As EST Ee 216 23 7 2 Historical Results MON MONTOS a a 216 23 7 3 Storingasta cgraphimage Of results nica ia dia 216 23 74 EXPOLIO SIMUIQUON data sinss A ad 217 VAs E SMON OTO E 217 237d Vdeo RECON ia A A de 217 23 8 INTERPRETING INE AAA A EN 217 238d TOV EE 217 238 25 lt PUGIOW TEVE Oli A 217 23 8 3 Choked and Alternating Airflouws En 218 23 9 VENT FIRE EIIMITATIONS st AA EA A AAA AA AA AA AAA AAA AA 218 23 9 1 Fire effect simulation not fire chemistry simulation 0sn0nnn0nnn0n00n000nnnnesoren
160. cesscsssesscessesscsssesssesscsssesscessesscessessseusessesscessenscense 192 20 4 EEGENEN 192 20 4 1 Placement of Refrigeration SOUFCES En 193 20 4 2 What portion of the air iS cooled En 194 DIESEL PARTICULATE SIMULATION DPM ccccccssccccssssssssssssccccccsssscsssssssccnsccccccssssecssesssccccccccccesseseesesssscccnnsccseees 196 21 1 APPUCATION OF DP IVISIMUIATION EE 196 21 2 HOW TO PERFORM DPM SIMULATION IN VENTSIM RENE NENNEN 197 Da D De ed A 197 STAGING ALE VERSION Tira AAA AAA AAA AAA AS 200 22 1 EE TAG ING TA Need 200 22 1 1 Example 1 Multiple Stage Time ne 201 22 1 2 Example 2 Multiple OptiONS o oococooooococcononnnooanonanconon conan nonan conan o ron o nono no ron ronca nonnn ronca rozan nono 201 22 1 3 Example 3 Totally different model 201 22 2 USING TAGE A A A sd o 202 2224 SCHING EENHEETEN Re 202 2222 EE 202 22 2 3 Assigning airways to different STAGES En 203 22 3 CREATING A UNIQUE VERSION OF AN AIRWAY FOR A STAGE cccccccccssssssesssscccessccseccsssssessssccceescesscsssssssesssscecesesesssssssssees 204 22 4 SUGGESTED TIPS FOR DEVELOPING STAGED MODELS sssssssssssssssssssssssseesseeesesssesssssesesesssssssesessseseseesessssssesssssessessssesess 204 2241 ENEE ENEE ET 204 2242 SUGKEAIVMOG O E 205 2243 Other Uses for SOON A aes A A eases 205 VENTFIRE SCENARIO SIMULATION PREMIUM ssccccccsssssssssssssscsssscccccesssesssssssccccscccccessssecsssssssccc
161. change the airway length and resistance making it invalid for true scale model simulation Scale Airway Size A utility which scales all airway dimensions by an input factor This effectively reduces or increases the size of the airways in the model Warning this function will rarely find a practical use One possible use is to incorporate an over break factor into mine design airway dimensions as mined airways are often slightly largely than design Scaling model airway sizes will change the airway resistances making it invalid for true scale model simulation 5 7 2 Airways Modify a selection of airway specific parameters Lengths Fixes or un fixes airway lengths so that models may be manipulated without changing the calculated airway lengths Fix AllLengths This will fix and protect all airways in the model from changes in length when moving airways This may be useful if airways are required to be moved for clarity but lengths must remain the same Unfix All Lengths This will un fix and recalculate all true airway lengths in a model This function will recalculate airways lengths and hence change any previously fixed lengths If there are any doubts use the EDIT function to individually fix unfix lengths of only the airways that need to be changed 5 7 3 Auto Name Automatically places a code number on every airway without a current airway name A letter may be specified to head the number if desired e g B157 Sequences t
162. cing ventilation costs is applying ventilation only when and where it is needed While simple in principle this fundamental approach provides significant challenges when applied to complex models Changes or reductions in ventilation flows can significantly impact other areas of the mine resulting in recirculation and heat and gas build up Using Ventsim Visual different scenarios can be easily examined by simulating potential changes such as reducing or turning off fan flows or reducing refrigeration The model summary will predict savings made in ventilation costs and power for the change The recirculation checker in Visual Advanced will quickly check for any recirculation resulting from the change The contamination and diesel particulate tools in the Advanced version will estimate any change to exhaust and potential fume The thermodynamic simulator will identify any unacceptable changes to temperature Doors fans and stopping can be quickly placed to control model airflow to acceptable levels and provide useful information as to what automatic controls may be required to achieve the ventilation changes Ventsim Visual User Manual Page 239 26 4 Fan Optimisation Correctly sized fans can significantly reduce operating costs Ensure airflows are not significantly overdesigned and fan curves and duty points are closely matched to run efficiently Many fan curves rapidly lose efficiency away from the central duty points
163. collect data once every 10 increments The frequency at which the screen will be updated and graphically show the progress of the simulation For example a frequency of 10 will display the graphics every 10 increments iterations Lower numbers will result in a smooth display update but will slow down simulation particularly for large models The number of data points available for recording monitor location results during dynamic simulation For length simulations or models with a large number of monitors this may need to be increased If a simulation exceeds the available number of points it will ignore the overflow The number of sub cell divisions that airways are divided into during dynamic simulation Each sub cell moves independently through a model during simulation collecting gases heat and contaminants Cells movements and speed is controlled by the air simulation Note Ventsim will always target the maximum number of sub cells however the number of cells cannot be more than the time it takes to travel one increment of time Therefore for example if an airway passes air from start to end in 10 seconds and the dynamic increment is 5 seconds then a maximum of only two sub cells could be placed in the airway Smaller dynamic increments will generally allow more sub cells to be used resulting in more accurate but slower simulation For small models the simulation may progress too fast to visually track changes A simula
164. combustible products used in VentFIRE simulations Combustible products are defined by the amount of heat released MJ kg the oxygen consumption kg Oxygen per kg fuel burned and the yields rates of various combustible products kg combustion product per kg product burned Note that the yield of carbon monoxide is specified as a minimum and maximum This provides some flexibility in the emission rates for oxygen rich and fuel rich fires If the calculated equivalence ratio ratio of fuel available per oxygen available exceeds above 1 then the maximum CO value will be used in simulation It the ratio falls below 0 5 then a value close to the minimum will be used For ratios between these values a value between minimum and maximum will be calculated increasing towards the maximum value as the ratio approaches one 1 The equivalence ratio is not fixed and is constantly recalculated during simulation Defines the resistance of leakage of air from a Ventilation duct The values define the area sum of holes per total unit area specified as mm2 per m2 of duct Because this ratio uses the same units any number representation of the ratio x 1 x 10 million could be used for example parts per million ppm Defines a mixture of gases that can be applied to airway gas simulation If the total volumetric concentration of gases defined is less than 100 then the remaining volume will be used during simulation to allow airway gases to volumetrical
165. ction The shock length type can be set in the setting menu Atkinsons friction factor describing the uneveness of an airway wall resulting in near surface turnulence and increase airway resistance Friction factors are standardised to the surface density The size of an airway width and height as the centre section The perimeter of an airway calculated from the centre height and width taking into account the airway shape profile The perimeter can also be set directly from the edit menu The area of an airway calculated from the centre height and width taking into account the airway shape profile The area can also be set directly from the edit menu The true length of an airway used to calculate airway resistance and heat transfer It does not include additional shock lengths if specified Ventsim Visual User Manual Page 259 29 1 5 29 1 6 Coordinates Energy Power Cost Power Loss Power Loss L Power Input Head Cost Head Cost L Fan Fix Cost Thermo dynamics Wet bulb Dry bulb Effective Temperature Dew point Cooling Power Report the coordinates of an airway in eastings northing and elevation The friction loss along an airway converted to an equivalent theoretical work load This value does not include power efficiencies which would result if the pressure loss was to be overcome electrically The friction loss along an airway converted to an equivalent theoritical work load per uni
166. ctors can be added to the drop down list in the Preset gt Friction Factor section of the program settings Leakage Porosity A leakage factor representing the portion of the duct surface with holes compared to the total duct surface By default this measurement is in mm m which could also be considered as hole parts per million Higher values represent higher leakage Placing a zero 0 in this box represents no leakage Modelling leakage will increase model size and simulation complexity therefore leakage should only be specified if it is specifically required to be modelled Ventsim offers a number of default porosity factors in the drop down list however these are subjective and can be altered in the Preset gt Leakage section of the program settings Ventsim Visual User Manual Page 170 During simulation leakage will demonstrate reducing airflow further along the duct away from the fan Fan pressures and duct diameter together with leakage factors will influence leakage amounts Leaked air is returned to the airway at the position it is leaked from the duct Leakage Intervals This specification is an internal instruction to Ventsim to build a leakage path an invisible duct into the airway at frequent intervals to allow air to leak back into the main airway The resistance of this path is calculated automatically and is a function of the leakage factors and the leakage interval In most cases it will not alter the simulation
167. d Drive Space 100 Mb e Direct X9 compatible graphics minimum Intel integrated graphics e Two button mouse Recommended Configuration e Intel based 32 or 64 bit dual core processor 2 Ghz e Windows XP Vista or Windows 7 32 or 64 bit e Memory 4G of Ram Hard Drive Space 100Mb e Dedicated Discrete Graphics card from INTEL ATI or NVIDIA with greater than 128Mb or RAM INTEL COREi processors generally sold from 2010 onwards now have reasonable graphical power and perform well with Ventsim without a dedicated graphics card e Two button mouse with centre scroll click wheel e Ventsim Visual is not officially supported on Apple Mac computers however it has been confirmed that Ventsim Visual is capable of running on newer Macbooks under Windows dual boot or Parallels virtualisation software Ideal Configuration e Windows 7 64 bit 4Gb or more RAM Dedicated 1GB NVIDIA or ATI graphics card Page 19 3 VENTSIM CLASSIC TO VISUAL GUIDE r r veces ee a e H B ertam Van H Zeng 12 17GRAWOSOF om o G VENTSIM 12 17 SRAWDSOP simj Scale 1 1365 View 1 U Ground Quantity E oo gt e e W A Mecos oe file Edt View Rum Tools Window Help Sin en Me fat ee Sevedwenwe fun Comed Te aterg Window Her E EMA DF so AO rm A A AS e D I Tata gt Queria S y Mel A 2 lt ls BSL oo de W 17507 m Comprende Mol MVP Biel zen D Ventsim
168. d factors so ADVANCED that an unlimited number of different sizes can be considered See the financial optimisation section for further information 5 5 8 Contaminant Simulates the downstream spread or the upstream source of contaminants in the air These Simulations routines are generally used to identify the path and spread concentration of fumes gases dust and smoke from a contaminant source or to predict where the airflow for a particular location comes from The routines are not generally recommended for large fires due to the dynamic and changing nature of fires and the dynamic heat effects on natural ventilation pressures To clear any contaminants or gases from a ventilation model select the Clear Contaminants option from this menu or the toolbar menu See the Contaminant Simulation section or the Gas Simulation section for further information 5 5 9 Summary Displays a summary of the current model collectively or grouped under different 74BS The data may be copied to the clipboard for pasting into another package such as Microsoft Word or an email Note that if Staging is used then only the currently viewed stage is summarised An example output is listed below from the Advanced version with explanations MODEL AIRWAYS 2772 Total number of discrete airways in a model Total length 66196 0 m Total summed length of all airways Total airflow intake 1025 5 m3 s Total airflow entering the mine from the surface Total
169. d spread to the entire unit Numerous fuel types are present including diesel fuel rubber tyres hydraulic oils and cabin plastics an each could burn at a different time and rate The rate of combustion depends on available airflow and oxygen confinement of the fire exposure of the fire source and numerous other environmental considerations Poisonous gas emissions from the fire are highly dependent on surrounding airflow temperature of the fire and types of fuel burning It can be seen that trying to accurately predict all of these factors would be extremely difficult the range of possibilities is endless Therefore it is important to consider that Fire Simulation in software should not necessarily be about trying to accurately simulate the fire itself but rather to simulate the range of effects that different sized fires may have on the mine environment By considering a range of possibilities and the resultant potential effects on the mine environment an idea of the impact of a fire can be assessed and emergency response plans and mine ventilation design changes can be put in place 23 3 How it works VentFIRE uses a discrete sub cell transport and node mixing method to simulate moving parcels of heat and gas around a mine To dynamically model mine ventilation and accurately take into account continual changes in atmospheric concentrations of gases and heat including recirculation VentFIRE breaks Ventsim Visual User Ma
170. d to airways on import then this function can be used to select or fence the reference lines that are to be converted to airways Note that each reference line can only be selected once as the program will not duplicate multiple selected lines Convert Any If centre lines are not available this is an experimental feature which agglomerates groups of reference graphics to try and establish an airway path which could be constructed Examples may include survey string data showing wall floors and backs or 3D solids of Ventsim Visual User Manual Page 79 actual mine development or shafts Note that the results from this function are very approximate and will likely require significant manipulation with the MOVE and DELETE tool function after being done to create a workable model Measure Allows the mouse to measure distances between two points Click on the start point of where the measurement will start and drag the mouse to the end point The measurement will display in the bottom left Status Bar area of the screen 7 3 3 Edit i Place the program into Edit mode Left Mouse Click Edit the airway Left clicking the mouse on top of an airway will show the Edit Box for that airway Left Mouse Drag Selects the airways within the fence box being drawn Selected airways can then be edited by clicking on any of the selected airways Hint Selecting Multiple airways permits attributes for a large number of airways to be changed simulta
171. ded with the dynamic monitors to show a history of results The DPM levels can be dynamically adjusted by PAUSING and editing or moving the machines around during the simulation and then RESUMING the simulation For further information see the DPM SIMULATION chapter 18 7 Dynamic HEAT Simulation Dynamic Heat Simulation is a potentially complex function that can help determine transient or changing mine temperature based on changing conditions through the mine For example surface temperatures machines refrigeration or mining activities can be changed during the dynamic simulation to determine the effect of the changes over time on the mine atmosphere at different locations in the mine Temp Wet Bulb o LE 3 a 5 a E e A nb as y AN x E oh gs GH SIMPLE LIS PSPS DY PRPS GOD rrr GG e e e GG e e e e e e GG e e e e e e Time Second To calculate the true dynamic effects on the mine atmosphere the mine rock surface boundaries must be considered to have reached a stable boundary temperature so that short term changes in mine atmosphere temperatures can be released or absorbed by the rock at levels similar to the initial rock exposure receptiveness Ventsim Visual User Manual Page 183 This creates a thermal buffer or flywheel effect that effectively reduces the downstream impact of rapid temperature changes on the mine atmosphere The thermal flywheel effect diminishes with exposure time however for the short te
172. degrees celcius should be treated with caution as the Effective Temperatures are not normally calculated beyond these limits and Ventsim only provides a correlated estimate The Effective Temperature is defined as the temperature of still saturated aur which would give the same thermal feel as the actual environment being consdered The Air Cooling Power methods described below are generally considered to provide a better index of cooling The dew point is the temperature to which a given parcel of air must be cooled at constant barometric pressure for water vapor to condense into water cooling power of mine air determines the capacity of the ambient atmosphere to dissipate the metabolic heat generated by humans The cooling power is measured in W m2 amount of heat removes from the human body per second per unit surface area to keep skin temperature ACPM method or body core temperature TWL method below safe limits It is dependent mainly on the wet bulb temperature and the air velocity Ventsim Visual User Manual Page 260 TWL Method Developed in Australia and based on body core temperature limits the Thermal Work Limit method has been developed from a physiological basis and ratified by the Australian Institute of Occupational Hygienists AIOH It has been adopted by many Australian mines and uses standard clothing and sweat factors The method ideally requires globe temperatures for accurate resutls As these are not available from a
173. dels can be built either by hand with the mouse or imported from a CAD program While a ventilation model can be built schematically in Ventsim it is highly recommended building a true to scale 3D model if possible to allow Ventsim to automatically use parameters such as size length and depth for simulation For compressible airflow models this allows for automatic density adjustment and natural ventilation pressure application resulting in more accurate and realistic results In addition rock temperature and autocompression can be automatically calculated for heat simulation 15 2 Types of Models A ventilation model must have a framework of connected airways or branches For airflow to successfully travel along an airway each airway must have a connecting airway at the entry and exit Airways with no connection at either end will not carry airflow unless connected to the surface A ventilation model can be developed as either a closed or open model A closed model does not have any airways connecting to the surface While this would be unusual for a real mine for diagnostic purposes it is possible to build and simulate an entirely closed model which continually circulates air around the modelled airways To construct a closed model simply connect and loop all airways so that they form a continuous Ventsim Visual User Manual Page 158 path and all airway ends are connected to at least one other Because a closed system is entirel
174. dered as a potential source of the contamination Report Fresh Again used in the contaminant source tracking routines this will place a fresh air report within an airway After a contaminant tracking finding simulation all airways above this point will be considered as fresh air Places or removes one of the above types of contaminants Records ventilation conditions at this airway location during dynamic simulation See the Dynamic Simulation section for more detail Applies a filter to selected airways to simplify or bind together airways See the TOOLS gt FILTER section for more detail or more control is required on how the filtering is applied 7 4 Simulation Functions The simulation functions control the major simulation capabilities of Ventsim Visual The buttons assumes that a valid model has been created and all required data has been entered in preparation for simulation 380 G0 4 056 uy Performs an airflow simulation on the model data For more information see Airflow Simulation 0 Performs a thermodynamic simulation on the model data For more information see Thermodynamic Simulation Performs a steady state contaminant simulation on the model data Contaminant sources or flag must be present in the model to work Three different types of contaminant simulations are available from the sub menu pull down arrow to the right of the icon See the Contaminant Menu bar for more information Ventsim Visu
175. dialog box to allow the move to be specified as a coordinate or offset from the current position Left Mouse Drag Shift Drags the airway or node to a new location in the vertical plane adjacent to the viewing screen The Edit Plane is moved with the dragged airway to indicate where the elevation is in relation to other airways 7 3 10 Copy Copies the selected airway airways or icons to a different location The original airways or icons remain in place Left Mouse Click Opens the coordinate entry dialog box to allow the copy to be specified as a coordinate or offset from the current position Left Mouse Drag Drags the copied airways or icons to a new location If the ICON is being copied it will show on airways under the mouse cursor When moving airways a true vertical line is displayed showing where the move point is in relation to other airways To copy an icon such as a fan heat source or resistance along an airway simply grab the icon with the left mouse button and drag the icon to another airway Left Mouse Drag Shift Drags the copied airways to a new location in the vertical plane adjacent to the viewing screen The Edit Plane is moved with the dragged airway s to indicate where the elevation is in relation to other airways 7 3 11 Reverse Cy Reverses the direction of the selected airway The direction of the airway and the airflow within the airway is reversed Fan fixed flows and pressures are also reversed
176. different inputs can be specified for Radon and progeny concentration in an airway Typically the Radon emanation will be specified based on the exposed area of the surface of the airway In addition if broken ore or rock is present the user may elect to calculate an extra Radon addition into the airway This is normally calculated by estimating the emanation of radon from the exposed ore surface based on the area exposed m2 and also from within the ore pile based on the m3 present The additional Radon calculated can be added to the airway in the second field Radon Addition Alternatively the levels of Radon concentration and progeny levels can be specifically set in the airway using the FIX options in the 3 and 4 setting These factors will override any calculations derived from the emanation settings and will ensure any airflow exiting the airway contains these values These settings should only be used where there is a known concentration as they will override any prior estimates of radon activity travelling through these airways The emanation settings should not be used simultaneously with the fixed settings in the same airway The Activate Radon checkbox will ensure the radon settings of the airway will be included in the Radon simulation Deselect this box if the settings are not required to be used in the simulation Ventsim Visual User Manual Page 232 File Select Airways Tools Airway Fans Heat Contaminant Gas Dynamic
177. ding or removing an evas from a fan for example can significantly change the fan performance within Ventsim although the fan total pressure curve will remain similar Where only a static curve is available the diameter can help estimate velocity pressure from the fan and the associated power consumption Where only fan total pressure is entered the fan diameter can help estimate available fan static pressure a consideration for the performance of surface exhaust fans Finally the fan diameter can also help estimate new curve points for the fan database if either the fan static or total curve is unavailable See the fan database section for more information Hint It is recommended that where fan pressure curves are provided without an evas which is normally how fan manufacturers provide the curves as mines may mount the fan in different configurations any evas effects can be independently modelled by using the edit box options to place an diffuser in the airway Fan speed is a manufactures reference to the normal speed of the fan operation for the specified fan curve The number is not directly used during simulation and will not influence simulation outcome The percentage fan speed can however be adjusted in the EDIT box Reverse P and Reverse Q modifies performance for fans run backwards for an emergency situation Most manufactures will not supply these figures as fans are not generally designed to do this although some fans can
178. disation of ores e Heat from auto compression of air e Refrigeration and spot cooling of air e Changing densities throughout the mine due to depth and temperature effects as well as pressure from ventilation flows e Natural ventilation changes from changing densities e Moisture from sources such as dust suppression sprays e Condensation from over saturated air Ventsim Visual User Manual Page 52 5 5 3 5 5 4 5 5 5 5 5 6 To accurately model a mine all of these factors must be considered If data for a parameter is not entered Ventsim Visual will assume a default value specified in the Settings and in most cases will simulate a result anyway The accuracy of this result will largely depend on the accuracy of the entered data and the default values used More information regarding thermodynamic simulation can be found later in the manual Diesel particulates Simulates the spread of diesel particulates throughout a mine model derived from diesel ADVANCED Dynamic Simulations ADVANCED VentFIRE PREMIUM Recirculation ADVANCED heat sources placed throughout the model The simulation process assumes a steady state emission of diesel particulate sources and a uniform mixing process throughout the model and its junctions Note that this may not always be the case in a real mine where incomplete mixing and dynamic changing of exhaust emissions through the day can change concentrations of diesel
179. ditional FTP beyond the simulated result may be required to achieve the simulated results As every fan and installation is different it is best to discuss this with your fan manufactures in pressure critical installations Fan Power The fan power is calculated on Fan Total Pressure FTP and represents the power the fan motor is applying to the fan blades to generate the pressure and flow through the fan The fan shaft absorbed power is calculate from the fan power curve If a power curve has not been set for the fan the fan total efficiency curve is used in conjunction with fan total pressure and volume flow to calculate shaft power If th s is unavailable the default fan efficiency is used Fan Electrical power is the estimated electrical power drawn by the fan motor It is calculated from the Fan shaft power factored up by the motor efficiency factor set in the Settings menu Fan Cost The annual cost figure is derived from the power cost set in the Setting Menus for a fan operating at this duty point continuously for a full year Fix Present Fix flows or pressures are often entered where a specific fan is not available or needs to be calculated The fixed flow information in particular is useful for identifying duty points for fan pressure at a specific volume This point can then be used to specify and source a Suitable fan with a curve that can matches the pressure and flow Fixed Duty Point A fixed flow will show a Collar Total press
180. due to wall friction This ignores any other resistances in the airway such as doors or stoppings Compares density differences of a column of mine air with an equivalent column of atmospheric air and applies a pressure differential Every airway with a different entry and exit elevation has potential to have some natural ventilation Ventsim Visual uses a ve number convention to describe upwards buoyant natural ventilation and ve to show downward sinking natural ventilation Note that by default atmospheric density is adjusted for temperature gradient lapse rate in much the same way as auto compression can drive changes in underground temperature at different elevations Inlet airways at different elevations will have different temperatures which are derived from the standard elevation and default surface temperature This function can be turned off surface temperature adjust in the settings if desired Total airway resistance along an airway The resistance is standardised to the surface density and includes any additional resistance added by the user such as doors and stoppings Resistance due to airway wall friction along an airway It does not include any additional resistances added The shock value reported as either a shock factor X or an equivalent airway length Both factor types add additional resistance to an airway and increase pressure loss due to air turbulence caused by a bend change of size or other obstru
181. e at a pump station discharge for example Ventsim Ventsim Visual User Manual Page 150 Visual will calculate how much heat is being lost from the water most of which ultimately enters the airflow Ventsim Visual User Manual Page 151 D 22000 S Single stage LETT Decharge Dan o ischarge Diam A HN ATI ig az A E i Wi ES LZ E E Le Le el re 5 SEE F HDH 14 FANS Fans are an important part of the modelling process Correct entry of data for fan curves describing the pressure and flow performance at different fan duties is essential for accurate simulation 14 1 Fan Database The fan database is accessible from the TOOLS gt FANS menu The fan database allows editing adding and deleting of all fans in the model fan database Up to one thousand 1000 fans and the associated fan curves may be entered into the fan database A display for each fan curve and data will be presented when a fan is selected from the display list The Edit gt copy and paste functions can be used to copy data to or from another program for example a spreadsheet Caution should be taken when deleting or modifying a fan as any model which may use the deleted fan number will not simulate correctly Diameter 0mm Speed 3 000rm nominal Power 45k wi Fans y F K ESTE File Edit Estimate lo aial Conventional Jet Fans beta Development Fan 18k W 0 29 im Reverse P 0 50
182. e 10 0 m Orientation of Elevation Normal Orientation of A Axis Normal Orientation of Y Axis Normal spacing for Grid 50 0 mi Controls Controls Snap Tolerance Adjust the willingness of the Ventsim cursor to adjust or join to other airways while drawing or moving airway items For finer control less propensity to connect to close airways reduce this number minimum 1 maximum 100 Use 3D Mouse Turns on an option to use a Connexion 3D mouse This type of input allows for models to be rotated panned and zoomed with a single control leaving the regular mouse free to operate menus and selection duties This option will have no effect if a Connexion 3D mouse is not present 12 3 4 Coordinates Grid North Orientation Defines the direction of grid north on the screen Therefore if grid north direction is defined as UP then the Northing coordinate numbers will start lower from the screen bottom to higher numbers towards the screen top If a GRID NORTH system is not chosen then this setting will show CUSTOM Grid System Most mines use a GRID NORTH system Ventsim s coordinate convention when using grid north coordinates is Easting Northing and Elevation in that order If another type of system is used then an XYZ system can be specified which allows for orientation of coordinates in any direction Some Ventsim CLASSIC models use a custom system and in this will likely be automatically set when a Ventsim Classic model is i
183. e Tinting Yes Screen Colour Bottom 0 0 0 Screen Colour Top C 100 149 237 El Brightness VU Colour Text Airway 255 255 255 Colour Text Data _ 255 255 255 Colour Text Node 255 255 255 Grid Colour ES 100 149 237 Grid Sheet MA 150 15 15 30 Print To White Background No Selection Colour C_ 255 255 255 Text Background 0 0 0 Colours Colors 12 3 1 Background Background Picture Sets a preset or custom picture to the background of the visual display This may provide some visual flair for presentations or may simply suit the users preferences An option exists to use a preset background current CLOUDS or GROUND or a custom background picture can be displayed by simply dragging a picture file from windows on to the screen Background Picture Tints the background picture using the Screen Colour Top and Bottom settings Note that Tinting a black screen colour will totally hide the pictures while a white screen colour will fully show the picture in natural colours Background Colour Colour of upper and lower halves of background The colours are smoothly blended to Bottom and Top provide a gradient effect Lighter colours may be more appropriate for presentations and report Ventsim Visual User Manual Page 126 Dark and stormy background image 12 3 2 Colours Brightness Controls the relative brightness and intensity of the colour displays on screen Grid Colour Colour of grid lines Grid Sheet Col
184. e airway Airways will normally source these values from the default values in the Settings menu however they can be individually overridden for each airway Using these functions it is possible to set parts of the mine with different rock parameters types or wetness fractions Rock Type Reset shale L Rock Type Conductivity 1 23 Wim Diffusivity 0 550 m2 3 11 specific Heat 650 0 J kgC Rock Density 2 631 kg m3 Figure 9 10 Rock Condition entry for airways Rock Type Specifies a rock type that has been pre defined in the Preset menu click on Rock Type to enter the menu Selecting a preset value overwrites any manually defined rock parameters Thermal Conductivity The thermal conductivity of rock surrounding the airway Thermal Diffusivity The thermal diffusivity of rock surrounding the airway This value is optional and can be derived by entering the rock density instead Specific Heat The specific heat value of rock surrounding the airway Rock Density The density of rock surrounding the airway This value is optional and can be derived by entering the thermal diffusivity instead Rock Surface Wetness Fraction Custom 0 15 Age Entry Ext 500 5 00 WET Temperature 425 36 9 Rock Temperature 0 0 0 0 Ventsim Visual User Manual Page 106 Wetness Fraction The fraction of the airway surface which is wet A value of 0 01 would describe a nearly dry surface while 1 0 would describe a fully wet surface The Wetness Fraction
185. e for a mine comes from auxiliary ventilated areas that need to be simulated as part of the overall mine heat balance To satisfy a model requirement for a continuous air pathway ventilation duct needs to be included as a separate airway For clarification this airway is best placed outside of the mined airway and sized according to true ventilation duct size The ventilation duct airway will carry air to the blind heading face The blind heading airways will carry airflow back to a model junction and then join any other airflow beyond the blind heading The DUCT construction tool in the drop down option box next to the DRAW button will automatically construct a duct airway parallel to a SELECTED series of airways Once constructed a fan or fixed flow just needs to be added to one section of the duct to simulate flows Hint Specify the air type of ventilation duct to a different type and colour Airway types can be displayed independently and the duct visibility can be turned on or off to improve visibility of the model e Ventsim Visual FanDuct vsm File Edit View SavedViews Run D FW 2a A Y amp Jairtiow Quantity D D4 GODOODGSL gt Tools Window Help 79 gt A cagage Ri 1 246 80 5 on y l 30 8 NWileakage eg went duct d 28 0 Units m3 s Coords 498 8E 486 7N 504Z blind heading 28 1 Figure 15 8 Example showing ventilation duct into blind heading Note the two leakage
186. e if only the fan database and the common resistance friction and shock factors are to be used then click on the Fan Database and Preset options in the dialog box Fan Database Preset factors Airway Defaults Mine Levels View Layers Save the Master File in an accessible file location A descriptor Optimisation can be saved with the file to explain information about what Colour Palletes components have been saved Program Settings Link Opens a dialog form to search and link to a Master File If the current Ventsim file has an existing linked Master file the new Link will replace the data in the Ventsim file An Bee alternative method to link a file is to simply drag and drop a eS ve Master File into the current Ventsim Visual window Figure 5 1 Master File Options Unlink Breaks a link to the Master file but does not change the Master File Any changes to file settings made after the link is removed will no longer update the Master File Update Refreshes the current Ventsim file with the data in the Master File This may be necessary if another file has modified the data in the Master File after the Ventsim file has been opened It is normally not recommended to have multiple files open accessing the same Master File as only the most recently saved Ventsim File will have updated the master settings If another file has updated the Master File while the current file is open then a WARNING w
187. e in simulation TO maintain maximum compatibility the resistance of all airways is fixed to the same value as the VnetPC file however if the file has correct airway dimensions the user is encouraged to remove this fixed value and utilise the AUTO resistance in Ventsim to calculate airway resistance from size and friction factor To do this select the airway or airways then choose the EDIT button and change the CUSTOM resistance to AUTO Ensure the airway size and friction factors are correctly set for each airway Warning Full VnetPC compatibility is not guaranteed and every file should be thoroughly checked for accuracy and consistency after import VnetPC files are missing much of the information Ventsim normally used to simulate models and assumptions are sometimes made which may not be correct Ventsim Visual User Manual Page 34 5 1 3 9 1 4 5 1 5 5 1 6 Validating Imported When loading Ventsim Classic or VnetPC models a simple validation check can be done by Merge Save Save As Master Link Models comparing the model Summary before and after a simulation For example immediately after loading the model select RUN gt SUMMARY from the main menu record the airflows and other data then SIMULATE the model and compare the new SUMMARY results If the results are very similar it is likely that there are no significant compatibility issues Joins two models together instead of erasing the currently loaded m
188. e pull down menu for all airways Custom values are fixed resistances that override the automatic resistance calculation and therefore ignore any pre existing airway shape size or friction factor Values can be type directly in to the resistance value text box One way Resistances Resistances are normally set to apply equal resistance to airflow in either direction however resistances can be specified to apply a different resistance when airflow is reversed To enable this function create a Preset Resistance and enter both a primary and a secondary reversing resistance in the preset spreadsheet This will force the simulation to consider an alternative resistance if the airflow is reversed from the direction that the resistance was originally placed If a reversing resistance is not required simply leave the reversing resistance value at 0 To swap the direction of a one way resistance use the REVERSE button on the ICON toolbar One way resistance that currently are applying the secondary reversing resistance will be shown in a RED colour on the screen Example of use for this function include resistances such as hanging flaps or swinging doors which may either seal better or alternatively swing open if airflow is reversed Resistance Density Preset Resistances are assumed to be entered at a sea level air density therefore can Adjustment change according to the air density at which they are applied Ventsim Visual wi
189. e truck can be estimated eg tyres fuel oil etc and assumptions can be made as to the rate of burning for Ventsim Visual User Manual Page 212 23 5 4 Preset Combustible Fuels 23 5 1 Heat Sources 23 6 1 Establish Settings example a previous incident may suggest a truck will completely burn within 2 3 hours The combustible material could be combined into a single fuel type in the Preset which combines by weighted average the heat and gas output of all the materials or alternatively the fuel mixture could be converted to an equivalent amount of an existing fuel type such as diesel to give total similar heat and gas output For a very large fire such as a coal fire the total amount of fuel burn rate may not be that critical if insufficient oxygen is present VentFIRE will only burn the amount of fuel relative to the amount of oxygen present Therefore overestimating the fuel burn amount will make no difference to the simulation if insufficient oxygen is present Up to 250 different types of combustible fuels can be added to the Ventsim preset database from the SETTINGS gt PRESETS menu Each type of fuel can have defined Heat of Combustion outputs oxygen consumption rates and emission yield rates of various gases per kg fuel burned Ventsim comes with a standard series of simple fuels with laboratory estimated heat and gas yields The user is welcome to make combination fuel types where the heat outputs and
190. e unique aspects of a 3D perspective view comes from an understanding of how it works Ventsim Visual has a number of guides to assist in viewing and construction in 3D 4 1 Point of Focus The view in the main 3D Ventsim window is essentially a view seen from a camera floating in space aimed at a point of focus Your eye is the camera The point of focus is always in the centre of the screen at a pre determined distance away from the camera You can move closer or further away from the point of focus with the Mouse Scro button and rotate around this point of focus with the Mouse Right button To move the screen to a different location the point of focus needs to be moved There are several ways to move the point of focus e Draw a window with the mouse around the area you wish to focus on The focus will move to the centre of the window at the closest distance of an object or airway in the window e Drag pan the screen with the Centre mouse button The point of focus will move along the current horizontal plane with the mouse cursor e Click on an airway while in the view mode or when in any other mode with the Mouse Middle button or a Right Left combination for those without a 3 button mouse This will automatically put the focus onto the clicked airway at the same viewing distance as was previously set If the object being clicked is a long way away this has the effect of quickly flying through space towards that objec
191. e variations can be averaged Every diesel engine emits a certain amount of pollutants which include noxious gases and solid particulates Regulators in many countries have introduced steadily decreasing emission limits on new engines known in North America as the Tier standard or in Europe as the Euro rating Generally speaking the higher the rating the cleaner the engine emissions should be The recently introduced Tier 4 standard is being implemented over the period 2008 2015 and demands emissions be reduced by up to 90 lower than previous Tier standards Engine emission results are tested and approved by the EPA in North America and many of these test results are available online from the internet The makeup of quoted diesel engine particulate matter PM can vary depending on engine type and fuel used however a widely accepted ratio range is around 50 60 elemental carbon 20 30 organic carbons and 15 20 other matter The two most commonly used standards are the elemental carbon value EC and the total carbon value TC which is the sum of the elemental and organic carbon components Current North American guidelines suggest an elemental to total carbon ratio factor of around 1 3X Unfortunately most EPA test results are for total particulate emission including non carbon particulates and do not state the different particulate composition Rather than introduce emission standards mining regulators focus on atmospheric exp
192. eate the new Primary layer names by utilising the Preset Value forms Select this from the SETTINGS gt PRESETS Menu or click the Primary Layer button on the colour toolbox a Ventsim Visual Preset Values er File Edit F Figure 27 13 Set airway layer names 9 Use the group edit function to select the decline airways 10 Use the select toolbar button to select all decline airways 11 Use the edit toolbar button to edit all selected airways Ventsim Visual User Manual Page 249 12 Change the primary layer name to Main Decline 13 Change the air type to Fresh 14 Change the airway dimensions to 5 5m x 5 5m 15 Apply the changes to the selected airways W Ventsim Visual Tutoriall vsm s el File Edit View SavedViews Run Tools Window Help E B F ld la B Ey amp amp Contaminants y Spread Mix D PO BOOOO BD RO DS Units Coords 11273 6E 10964 6N 1048 Z Figure 27 14 Initial selection of all decline airways 1 ms E 1140 11 687 0 1 151 0 1220 11 6950 1 151 0 Surface Close End 7 Show Data fF Exclude Fix Direction Group Length 291 m 3 Gradient 00 o i J Dittuser ro cb Orifice 0 0 ep E Alr Type k Primary Layer Sub Levels e Secondary Layer 0 r S i E D D DD Figure 27 15 Select and edit the decline airways 16 Repeat the above actions to set the other airways parameters for shafts and sub levels Ventsim Visual User Manual Page 250 17 F
193. ecommended that FTP TOTAL PRESSURE fan curves be used throughout an entire model if possible however if this is not possible then the entire model should use FSP STATIC PRESSURE fan curves instead Both types should not be mixed throughout a model as a mixed pressure solution may overestimate the performance of any fan using an FTP curve as the surface velocity pressure loss is ignored Reverses the fan blade direction during simulation This item is useful for emergency simulation where fans are available in the model to reverse airflow at specific locations The fan curve is adjusted by the reverse factors set in the fan database to reflect the poorer performance of fans with blades run in reverse The reverse function is only available for fans not fixed flows or pressures Ventsim Visual User Manual Page 101 9 5 1 9 5 2 RPM Fan Duty Point EDIT amp Fans Stalled Low Pressure or Negated Warning This is not the same as reversing a fan installation direction where the maximum fan performance would be applied in the opposite direction the reverse toolbar button should be used for this purpose instead Adjusts the fan blade rotation speed from the default setting defined by the fan curve in the Fan Database Note that this is a theoretical pressure and flow adjustment which may not exactly meet true fan performance at different speeds Hint While the simulated speed adjustment to a standard fan curve s
194. ection click the 2 Sensor Data Input 29 Dec 2011123615 T a SOURCE button on the Settings sheet to ee neem ensure a valid connection has been 2 974703 28 Dec 2011 21 made Ventsim Visual LiveView a Seege 23 76999 28 Dec 2011 21 should display a table spread sheet SE listing all available data If no 29 3071 28 Dec 2011 21 information is shown or an error is 39 64058 28 Dec 2011 21 displayed check the input parameters AD E p y p p 2 1278 28 Dec 2011 21 and try again 0 5843696 28 Dec 2011 21 To find out more about what settings and values Ventsim Visual LiveView will accept use the menu FILE gt EXPORT gt SENSOR DEFINITIONS and SENSOR UNIT SCHEMA in the Setting Form to view a copy of different codes that can be used when importing sensor data Including additional sensor codes for example Sensor Type numbers in your data source can reduce the amount of editing required after importing the sensors For example the UNIT SCHEMA export option shows what code numbers can be used in the UNIT TYPE column in the sensor data This column is used to specify the type of data the sensor is providing to LiveView and will automatically be shown correctly when imported If the information is not present the user will need to specify the type of sensor data manually after importing 24 2 3 Step 4 Mapping _ lt sumetemeMepping Schema Sa It is unlikely that the sensor file or database the Sensors ele eg
195. ed The fan is operating at too higher pressure low volume beyond the limits of the fan curve None required however fans should not be made to run outside the curve Ventsim Visual must guess a result which could lead to errors The fan is operating at too low pressure high volume beyond the limits of the fan curve None required however fans should not be made to run outside the curve Ventsim Visual must guess a result which could lead to errors or air balancing issues To remove the warning increase the resistance the fan operates at or extend the fan curve down to zero pressure The fan offering no additional pressure to the model and may actually be retarding airflow None required however fans should not run as negated Ventsim Visual must guess a result which could lead to errors or air balancing issues In most cases fan negation occurs as a result of other fans drawing air through the fan at a flow above the maximum fan curve quantity To remove this warning consider removing or switching off the fan The airflow in an upcasting shaft fall between the critical velocities that may cause the water to be suspending in the shaft None required This warning shows when the Settings gt Airflow Simulation gt Water Suspension checking is set From a design point of view this situation may not be desirable and the airflow may need to be increased or decreased to ensure velocities fall outside
196. ed large models this can help clarify intended data significantly 3 2 Animation They say a picture is worth a thousand words Animation may therefore be worth a thousand pictures Ventsim Visual animation again demonstrates a key feature of the software s presentation of complex data By animating flow arrows fans and heating cooling sources Ventsim Visual can show a huge amount of data in a way that the human brain can quickly visualise and interpret Animated flows show the direction and relative speed of all airflows in a mine over potentially thousands of airways Animated fans show whether they are turned on or off while dynamic colouring draws the user s attention to specific data ranges Using only animation and colouring of data Ventsim Visual users can process and analyse complex models without having to interpret a single line of textual data In addition it makes presentation of data very effective to the layperson who often control budgets and have to make decisions regarding investing in costly ventilation infrastructure 3 3 Elevation Database Levels There no longer needs to be a defined surface level elevation Any airway can be connected to the surface at any place in the mine by clicking on Connect to Surface in the airway Edit Box Ventsim Visual will calculate which end is connected to the surface based on the free end available A level database although still useful is no longer mandatory for vi
197. ed two dimensional lines Correct airway lengths can be entered by fixing the length under the Edit From Ventsim Visual User Manual Page 160 15 3 3 Spreadsheet Text Import 15 3 4 DXF Graphics Import Import DXF Graphics Line Data Warning Schematic Models although convenient in simplifying mine airway models have major restrictions which can affect their functionality in Ventsim Visual Ventsim Visual uses true airway locations to calculate changes in air density and heat properties of rock and airflow and as such schematic models are largely unsuitable for Ventsim Visual Advanced models which simulate deep mines with compressibility effects or for heat simulation Where a list of airway coordinates and sizes may be available from a database or another ventilation program for example these can be directly imported into Ventsim Visual using the File Open Text Function Data to be imported must meet a specific TAB delimited data format This format can be loaded and saved by most office application software such as Microsoft Excel or Word This format can be viewed by saving any existing model file as a TXT file format under the save menu For large models that need to be built to scale from existing mine workings or designs the best method is to import line string data AutoCAD Drawing Exchange Format DXF DWG Datamine or Surpac and allow Ventsim Visual to construct a model from the imported data lines The import
198. ees will have column names that correspond to Partial Name SENSORNAME K Optional names that LiveView expects LiveView Time Record TIMESTAMP y X Optional needs to know the column formats and names Column Format 9 Single sensor value per row Schemas so it can correctly import the right ps kind of data into the correct fields Single Sensor True Data VALUE v Required For example LiveView needs to know which column contains the date time and which column contain the is 7 We Optional sensor data To assist LiveView the user must link or i SL kee MAP the LiveView names with the external data Simulate v X Optional source names Equipment Type v X Optional Ventsim Location X Optional At a minimum the Sensor ID NAME and Sensor x y X Optional VALUE true value needs to be mapped to 7 lia tonal LiveView Sensor values should be numbers Z e x Optional only and must not include text such as unit mn names Other items such as sensor time location data type and sensor type can also been mapped if present in the data source however these items can be defined later if they are not defined in the data source If LiveView has not found an equivalent column name in the source data the item will be left blank This item can be mapped by Ventsim Visual User Manual Page 224 clicking the combo box and selecting which column name in the imported data file is matched with
199. eful pressure to the system and may even retard airflow that would otherwise flow more freely without the fan This may be a result of other model factors or fans forcing or drawing air through the fan When Ventsim Visual encounters a low pressure or negated fan situation it applies a resistance for airflow through the fan above the highest curve quantity This mimics real life performance of fans and effectively restricts airflow moving through a fan above its limit Ventsim Visual User Manual Page 102 9 5 3 9 5 4 9 5 5 Fan Pressure Curve Fan Efficiency Curve Fan Power Curve ADVANCED The induced resistance results in an additional pressure drop and in negated situations the fan may apply a nominal negative or resisting pressure effectively acting as a brake or orifice for the airflow Any of these situations are not desirable as fans are not designed to run beyond their fan curves Without a fan curve Ventsim Visual is forced to approximate fan performance and power consumption While stalled low pressure and negated warnings can be ignored every effort should be made to reduce or eliminate these occurrences within a model The fan pressure curve associated with the fan or fans if combined is selected in the airway Note that the fan curve may have been adjusted by the simulation from the curve entered in the fan database to reflect the change in air density at the fan location The fan
200. emperatures between simulations This is because the natural ventilation effects may cause airflows to change which in turn changes heat build up in airways which again can change the natural ventilation pressure This endless cycle of change cannot always be resolved and can lead to variable normally only small changes simulation results Applies compressible flow effects to airflow based on elevation and fan pressures As a result airflow volume will change depending on depth and temperature although mass flow will remain the same ignoring any moisture content changes to the air Compressible flow effects become significant over a few hundred metres in depth and it is recommended for Advanced Version users to turn it on for more accurate simulate results Automatically optimises simulation settings to preset recommended values to achieve faster simulation speeds or slower but more accurate simulation The function automatically adjusts the airflow simulation allowable error the heat simulation temperature margin the minimum mass flow heat balance setting and also a number of other simulation factors such as convergence iterations All of these settings can also be individually adjusted in the Settings section below Where individual settings vary from the preset recommendations the simulation accuracy menu will show the setting as CUSTOM In most cases the simulation accuracy will have little effect on the final simulation resul
201. entered as a percentage eg 10 degrees eg 12 5 or a ratio of horizontal to vertical distance eg 1 10 Ventsim Visual User Manual Page 78 Draw Coordinates Shows the coordinate entry box after the airway is drawn to allow manual entry of airway end coordinates Construct Duct a tool for quickly building ventilation ducting which follows existing airways Select the airways you wish to construct ducting along with the SELECT button Satz Diameter 1 25 m Friction Factor 0 0000 Custom Leakage Porosity 0 Custom Leakage Intervals Offset Horizontal Offset Vertical Figure 7 5 The Vent Duct Builder Dialog Box See the Auxiliary Fan and Ducts section for further information Construct Ramp A tool for quickly building spiral ramps After selecting the tool draw the initial direction of the ramp and the ramp builder toolbox will show allowing gradients ramp bends straights and heights to be established A ramp can be previewed to try different factors before clicking BUILD to commit the ramp design to the model Radius Straight Length Radius Segments Initial Bearing 360 Gradient ve down 12 5 Slope Ramp Height 100 0 m Start 1 729 2 46815 2 196 0 m Clockwise Figure 7 6 Ramp Build Function Convert Centreline Allows the selective direct conversion of DXF reference lines to airways If imported DXF centrelines are shown as a reference layer on screen instead of automatically being converte
202. entsim ventilation software It became clear soon after the introduction of Ventsim Classic that very sophisticated and complex models were being developed with the program however the application and analysing of these models was restricted by the shear amount of data being manipulated In addition in models of many thousands of airway branches serious mistakes could often be made in the entry of data without being noticed Viewing and editing of large datasets was becoming increasingly problematic and use of these models by others not familiar with the mine was becoming more difficult A key factor in the development of Ventsim Visual was the observation that many sophisticated ventilation models were being developed in Ventsim Classic by bright engineers but then simply gathered dust once these engineers moved on and new engineers abandoned trying to decipher them Another key factor to the development of the next generation of Ventsim was the increasing demand to simulate and design underground environmental conditions to ensure suitable conditions for mine workers and equipment As a result Ventsim Visual Standard and Advanced were developed to address these requirements Primarily it has been designed as a ventilation tool which can operated independently of other mine planning packages but maintains a level a compatibility which ensures data from mine planning packages and other ventilation software can be passed to the
203. equesting to recalculate the shock losses using the alternative system The equivalent length method requires the user to estimate an equivalent extra airway length required to approximate pressure loss due to shock The shock factor X method uses a calculated factor derived from both empirical and calculated changes in airway areas and velocities Both methods are described in any number of ventilation texts Once the method is set the Edit Box will require an appropriate shock loss value for each airway The Edit Box can accept a manually entered number but also has a number of preset values as well as an AUTO function which will force Ventsim Visual to attempt to calculate a shock loss factor or an equivalent length Defines the minimum resistance at which Ventsim Visual will completely stop all airflow in an airway All preset resistances above this value will cause airflow in the set airway to completely stop Only one Preset Resistance value should be greater than the Stop Resistance value This function artificially restricts airflow and has the potential to cause simulation problems if used on too many airways The simulation will check and ensure that only one or nil preset resistances are greater than this value TRUE Forces Ventsim to calculate natural ventilation pressures derived from air heat and density differences in the underground model Natural ventilation pressures can sometimes produce unstable simulation air fl
204. er This option allows detailed checking of models and will identify areas of your model that may cause problems during the simulation process A model with too many redundant bulkheads bulkheads in the same airway path as other bulkheads or fans that are in the same airway path as other fans may result in a model that will not converge Finds and alerts the user to fans that are directly competing against other fans Finds and if desired remove bulkheads that are not necessary usually because another bulkhead in the same airway has already stopped the airflow Removes all airflow and temperatures from a model The simulation processes is restarted with fresh data Ventsim Visual utilises flows densities and temperatures from previous simulation to help it to recalculate new simulations faster and more accurately If data has been corrupted during a bad simulation which may have produced errors excessive airflows heat or densities this may hinder subsequent simulations from finding an acceptable solution or may simply produce further errors Resetting the model will remove all calculation flows pressures densities and heat It will NOT remove any values fixed by the user such as fixed flows pressures or heat sources 5 8 Settings A list of preset factors and characteristic used for placing in airways a Ventsim Visual Preset Values c File Edit Resistance Friction Shock Heat
205. er Simulation Airflow Ventsim Visual User Manual Page 131 12 4 1 Airflow 12 4 Simulation Simulation airflow settings directly influence how the airflow simulation operates Airflow Allowable Error 0 050 m s Auto Simulation Yes Compressible Airflows No Density adjust friction factors Yes Density adjust preset resistances Yes Fan Reverse Flow Factor 0 5 Fan Reverse Pressure Factor 0 5 lqnore Warnings No terations 500 Maximum Simulation Pressure 1 000 000 0 Pa Mesh Surface Airvvay Priority Yes Shock Loss Type Shock Factor Method Stop Resistance 1 000 000 000 0 Ns m6 Use Natural Ventilation Pressures Ho E Yarn On Direction Change No Water Suspension Checking No Water Suspension Lower Limit 7 0 m s Water suspension minimum length 15 0 Water Suspension Upper Limit 12 0 m s Zero Flow Limit 0 100 mxs Figure 12 3 Ventsim Visual Settings Allowable error Defines the level of accuracy Ventsim must resolve down to before an acceptable solution Auto simulation Compressible Airflows Advanced Density Adjust Friction Factors is displayed This should normally be set to less than 0 1 m3 s error If a final analysis is required it may be advisable to set this to 0 01 m3 s or lower The smaller the value the more accurate the simulation process but the longer it may take Automatically performs an airflow simulation after every modification to a model This will conveniently display airflow amou
206. er concentrations with the mining of uranium ore radon gas can also be present in lower concentrations in any type of mine Radon is released from rock surfaces along mined tunnels and from broken rock or ore during the mining process The amount of radon released is usually in proportion to the presence of uranium ore U308 in the rock however this can vary between mining operations and orebodies Hazardous exposure to radon gas results when the Radon element decays into lower order elements called Radon daughters during which radiation in the form of alpha and beta particles and gamma radiation is released The formation of these Radon progeny potentially exposes mine workers to harmful levels of radiation that can increase the risk of radiation related diseases such as lung cancers Most countries have strict guidelines on the amount of radiation that workers can safely receive over a period of time Because of the small volumetric portion of Radon in mine emanation into the atmosphere is instead normally specified in Becquerels Bq or Picocuries pCi which represents the potential decaying radioactive capacity of the Radon gas presence Once into the atmosphere the concentration is normally specified in Bg litre or pCi litre of air The release of the radon gas in Ventsim can be introduced in two ways either by the average emanation of radon per second over a m2 of exposed rock surface and or alternatively by an emanation rate of rad
207. er with currently stored Ventsim Icon Pictures Refresh Updates the Ventsim display with any changed icons in the model The should normally not be required Clear Removes any icon pictures from the Ventsim file The pictures are still available in the Windows folder if they are required again A series of tools to assist with securing comparing or linking pictures to Ventsim files The tools are described below e Compare Compares the current loaded file with a saved file Any obvious changes to airways such as moving deletion new attributes presets or sizes will be highlight on screen and in the error list box HINT This function may be useful where there may be multiple similar versions of the same file and it is unknown what changes may have been made between versions e Security Sets the file security with a password to prevent unauthorised changes or access In addition a password protected file cannot be merged with another To activate security for a file simply select this option enter a password and click what security option you wish to apply File blue_sky vsm Path C Program Files Ventsim Visual Examples Password Confirm Password View Only Figure 5 2 File Security Options e View Only Allows the model to be loaded and viewed but not changed in any way or re saved e Read Only Allows the model to be loaded and modified but not resaved or copied to a new model e Lock File
208. erall model efficiency is available from the model summary function Ventsim Visual User Manual Page 240 27 1 1 Suggested Steps 27 TUTORIAL MODEL EXAMPLES Several model examples are included with the Ventsim program The first example below describes the method used in creating the model file EXAMPLE1 VSM 27 1 Example 1 An underground mine is to be designed from near the base of an open pit that is 100m deep A decline will extend down some 140m below the pit floor travelling adjacent to a sub vertical orebody Three drilling production sub levels will branch off the main decline every 40 vertical metres starting at 60m below the pit floor Main production will be from the bottom two levels A ventilation shaft some 400m away outside the pit boundary extends from the mine base to the surface connecting all sub levels An exhaust fan on the shaft will need to pull 150m3 s to supply the mines production needs Fresh air is supplied to the mine via the main decline 1 Conceptually design a mine ventilation model incorporating the three simple sub levels Ensure air is supplied equally to each level 2 Due to power restrictions main exhaust fan power must not exceed 300kW What diameter shaft should be mined 3 Emergency plans require stench gas to be delivered from the decline portal to all parts of the mine What is the maximum time for the stench gas to be delivered to all areas of the mine 4 Select the toolba
209. ere stage names can be entered or modified In addition detailed descriptions for each stage can be entered and simulation events for air and heat can be enabled when the user switches between stages in the models For further information on staging see the Stage Section in this manual a Stage List Ih Use Stage EES T E Sim Sim a Musse Stage Name SE Piece Gat Initial Development Preliminary Pre Production The ultimiate ventilation model describing the final location and fans for the shafts Displays a READ ONLY list of currently viewed or selected airways in a spreadsheet form The spreadsheet of airway data is displayed can be copied and pasted to other applications such as Microsoft Excel or Word Up to 100 different types of data can be displayed on the spreadsheet To display different data types use the SELECT gt DATA OPTIONS menu to select which data you wish to display Ventsim Visual User Manual Page 59 5 7 4 Filter Data can also be removed from the spreadsheet by selecting EDIT gt REMOVE or using the right mouse button Data columns can be reordered by selecting the column title and dragging to a new location In addition columns can be resized and resorted by using the appropriate menu commands Hint While the spreadsheet function is not designed for editing data extensive data characteristics for each airway can be displayed and copied to external programs such as Microsoft Excel
210. ergency response procedure and test the effect on the airflow and atmosphere during a fire Gas addition during dynamic simulation is designed for adding or changing gas compositions independent of the fire source Gas mixtures can be defined in the PRESETS which can be directly accessed by pressing the MIXTURE button Gases can be added to a VentFIRE before the simulation in which case this function is not necessary or dynamically during the simulation The function can be used in two ways 1 If the Linear Emission IS NOT checked then the gas mixture will be applied to all air passing through this airway The air will be changed to the specified FIXED gas mixtures and all unfixed concentration will volumetrically balance to the remaining volume 2 If the Linear Emission option IS checked then the atmosphere in the airway will gradually be replaced at the rate defined in the linear emission boxes litres metre second The first option is designed to allow users to either change the gas composition of the air at a point in a mine perhaps because the user may have some sensor data they can apply or to specify the gas content of air that may be injected into a mine for example a GAG unit or NITROGEN inertisation system For example if gas is injected into a mine during a fire then the VentFIRE simulation will show a decrease in the output of any fires that are flooded with inertisation gases provided the oxygen levels drop
211. ese views In plan or section view airways at a different plan or section depth will be shown at a different scale in perspective view You can quickly change between views by pressing the P key on the keyboard 7 2 10 Flow Animation The animation play button animates the airflow arrows in the model The airflow animation is performed at true scale speeds with airflow arrows travelling at the simulated air velocities in the model Providing the model is designed true to scale the progress of airflow can be tracked at the same speed as expected airflow in the underground mine when set to X1 speed Ventsim Visual User Manual Page 76 7 2 11 7 3 1 X X5 X10 STOP Stage View Left Mouse Drag Left Mouse Single Click Left Mouse Double Click Middle Mouse Drag Figure 7 3 Animation Speed Control The animate toolbar button has a number of sub menu items Animate flows in true real time Arrows travel at the same scale speed as calculated air velocity Arrows travel at five 5 times the scale speed of calculated air velocity Arrows travel at ten 10 times the scale speed of calculated air velocity Stops flow animation Flow animation in large model can consume significant processing power and slow model response and rotation It is recommended flow animation be turned off when not needed on larger models Hint Clicking the main flow animation icon will cycle the airflow speeds through al
212. esosesesosssesonesesees 52 5 5 3 Diesel particulates ADVANCED ccsssccesesssesesscesesscesesscesssscesenscseuscesuscessuscessuscesuscesuscesnsees 53 5 5 4 Dynamic Simulations ADVANCED 0 cc0scesosssesosssesosesesosesesosesesoesesssssesosssesosesessesessesesneseseneses 53 5 5 5 VEntFIRE PREMIUM ii 53 5 5 6 Recirculation ADVANCED aaa 53 5 5 7 Financial Simulation ici 54 TR RE 54 5 5 8 Contaminant Simulations EE 54 5 5 9 EE 54 5 6 CONNECT MENU A add dado da 58 5 6 1 EE EEE Se See REE EE 58 5 6 2 te e e 58 5 7 Ke ei IR 58 5 7 1 A EEN 58 5 7 1 EE 59 5 7 2 EE 59 5 7 3 Seda NEET E 59 5 7 4 EE 60 5 7 5 1E1141 11418 EE 62 5 7 6 DUDES AA AA 63 5 7 7 C nvert EEN 64 5 7 1 AT 64 5 7 2 PU UGS ta 65 5 7 3 AUTO NOME ia 65 5 7 4 o Me eer eee eee 66 5 7 5 Reset Model EE 66 5 8 Ke Re 66 5 8 1 PESE EE 66 5 8 2 Biet 67 5 8 3 Natural Venta ION E de LES 68 5 8 4 COMDES S Dle FI OWS assis AAA AAA AAA E 68 Page 8 5 8 5 Simulation AccHrocH En 68 5 8 6 EE 68 5 9 A E PEO nn A 69 5 9 1 FA A e vious UA A E EA II 69 5 9 2 SA te daca sca toss creas ca dea cc E Po ek oe eae 69 5 9 3 TUDO AA A E OE 69 5 9 4 e 69 5 9 5 AUTO AMOO A vanes iii 69 EREECHEN 70 6 1 1 AP cere nnaern dee eeenens 70 6 1 2 er Ree 70 6 1 3 Ga EE 70 6 1 4 EN 70 6 1 5 ICONS OO CA PUR O ON 70 6 1 6 A III OU PUE TI EEE 70 6 1 7 EE 70 DA IO aia 70 6 1 9 Voto iia 71 6 1 1 nn 71 6 1 2 MOVE EEN 71 6 1 3 lee 71 x1 0 L
213. esscseessensenses 97 Figure 9 7 ee E FFICEION GIG SNOEK ECOS id AAA AA AA A A A a 97 Figure 9 8 e BOX Fan Orna EE 100 Figure 9 9 The Edit Box Heat Entry Tab Advanced Version Only 104 Figure 9 10 Rock Condition entry fOr GHW GUS AA aida 106 FIGUIC EE EGIE BOX Contaminant Input EE 108 Letellier EE 110 Ventsim Visual User Manual Page 277 FOU IES CODO Ad 112 Figure 9 14 Recording sheet for entering general airway information EE 114 Figure 9 15 Attaching sensors e Reie e 114 Figure 10 1 Model example before level selection sirsiran a A a A A AA 116 Figure 10 2 Model example Gfterlevel selection ii 116 EQUAL Preset TIBE OPON AAA AAA AEA 118 PIGUET 2 1 GA DATES ELE OVINA SS AAA A ASA AAA AAA AAA AAA AAA AA 129 Figure eelef deele EE 130 Figure 2 3 VENTA E e E EE 132 PIQUIE 12 4 Sim lation CONTAR AN ESCUIN OS ennui inaa a i na ad 135 Figure 12 5 Simulation eeler CR 137 Figure 12 6 Eege eer le 143 Fig re 12 7 Ventsim Visual General Settings AAA AAA 146 Figure 19 1 AUTlOW CHUITO A T cit AEAEE AAA ANA ASA T 147 FIGURED EEN 148 PIQUE 13 3 DIESE eat ESOO y SA NAAA AA AACHEN AAA SEA AC AAA ASA 148 FIGUIE1 3 4 Diesel FUET CONSUMPUON ASIS Ei oi lia 149 EIERE been 150 Figure T3 6JeO EE ee 150 Figure 14 1 Fan Curve Entered into Ve acc 152 Figure 15 1 Example OF a Closed Model EE 159 FIGUIC1 5 2 Exame OF GN Open MOTE A AA AN AA AAA A SIA 159 Foue To Smor ed E da 162 FIGUIE E eelere DXF UNOS TO IWS oi ios bai 162 Figure 15 5 Example sho
214. etimes usefull if the original DXF data has been scanned or converted from a PDF file at an arbitrary scale and no longer matches the true scale Ventsim Visual User Manual Page 41 Rotate Default Colour Use DXF Colours Split Layer Names Filter Splines Rotates the DXF data around a zero based origin by a specified number of degrees Allows the user to select the colour of the reference data to import Colours the imported graphics to the original colour if selected or the user selected colour if not selected Imports the reference graphics into Ventsim with each layer as a different reference name instead of a single reference name encompassing all layers The reference names can then be individually managed in the Reference Manager function under the File menu Imported splines smooth curves can have hundreds of data points to make smooth curved lines This can consume excessive memory in Ventsim Select this function to reduce the imported data requirements and approximate the curves with a series of straight lines Import STR Surpac Strings Similar to DXF functionality Ventsim will attempt to import line strings and offer to directly convert to airways or import them as a reference for later use Import DM Datamine Strings and Wireframe Solids 5 1 13 Export DXF 5 1 14 Manage References Similar to DXF functionality Ventsim will attempt to import line strings and wireframe solids from Datamine c
215. ewing different elevations of a model While an overarching single elevation level covering all elevation ranges is still recommended any elevation range can be viewed at any time by Right Clicking the screen choosing Select Level from the context menu and then clicking or fencing the area you wish to view In addition the select level function can be used to quickly limit an elevation range or multiple ranges by drawing a box around the intended airways 3 4 Airways Airways no longer need to be connected to another and can be left open ended as would be the case in blind development headings Because this may still cause unintentional problems such as airways not joined as the user intends Ventsim Visual will alert the user to these during simulation These warnings can be turned OFF in the settings menu or disabled individually by clicking Closed End in the edit box No airflow will travel through closed ended airways unless connected to surface No Entry No Exit errors are largely abolished with Ventsim Visual Providing the airways are connected to a part of a model where a pressure can be derived Ventsim Visual will automatically reverse and adjust airways into a node 3 5 Data The single biggest change to Ventsim Visual is the visual management of data types Around ninety 90 different data types exist in the Advanced version all of which may be displayed as text on the screen in a spreadsheet or as a
216. f boxes representing each available stage is shown in the EDIT box Three different colours represent the current state of the selected airways If the mouse is hovered over any of the boxes a tool tip will show the name of the stage e Clear White shows that the edited airways do not currently belong to that stage e Blue shows that the edited airway all belong to that stage e Grey when multiple airways are being edited shows that some of the edited airways belong to that stage and some do not To assign an airway to a particularly stage simply click on the box representing the stage you wish the airway to appear in The box will turn BLUE and the airway will now appear on the screen when any of the set stages are selected from the main screen To REMOVE an airway from a stage click the box again and it will turn WHITE The airway will now NOT appear in the model when this stage is selected E A shortcut key is available that will quickly cycle between e ALL stages selected only the CURRENT stage selected e ALL current and FUTURE stages selected and e ALL Current and PREVIOUS stages selected This button fills in the required boxes automatically although the same result can be achieved by individually clicking each stage box Ventsim Visual User Manual Page 203 22 4 1 Option 1 Edit Box Auto Create Button Option 2 Create a copy of the airways Option 3 Construct a new airway Independent
217. facturers to find the correct value to use Ventsim Visual will apply this default value to diesel sources which have not been assigned a specific emission rate Specific rates for diesel equipment and airways that will override this default value can be assigned in the Presets or in the Edit box Temperature Limit Ventsim Visual User Manual Page 144 Mass Flow Limit Refrigeration COP Temperature Accuracy Maximum Heat Input 12 4 7 Recirculation Recirculated Airway Limit Advanced Recirculation Limit Volume Advanced The temperature limit above which Ventsim Visual will halt simulation and display an error if it occurs Temperature limits can be exceeded when too higher heat input is placed in an airway with not enough airflow Heat simulation uses a number of empirical formulas which are designed to work within a specific temperature range In general temperatures above 70 degrees centigrade will start to result in a reduction of accuracy of heat estimation The minimum mass flow that Ventsim Visual will perform a heat simulation on Below this limit Ventsim will assume the air is stationary and adopt the local virgin rock temperatures as the air temperature This value must be set above zero as portions of the program which calculate heat and moisture derived from rock surfaces must have some airflow velocity to work While there is some potential for heat imbalance errors by not taking into account low flow
218. fectively copying the airways from the original location to a new location Clones selected attributes from one airway and applies the attributes to another Attributes are physical airway parameters such as size friction factors and shock losses as well as identifying attributes such as layers You can decide which attributes to apply to an existing airway by selecting the Clone Options function from the menu or Select Manager Form from the toolbar To clone attributes select the Clone Attribute menu item and click on an existing airway The airway properties will be copied to memory and the program will automatically enter the Apply Attribute mode To apply attributes make sure you are in the App y Attribute mode if it has not already been selected and either click on an existing airway OR fence a selection of airways to apply the attributes to that group Cloned Attributes can be applied at anytime even after other editing has been done and will apply the most recently cloned values Ventsim Visual User Manual Page 46 Clone Options Size E Data Display Friction Factor E Heat Type Resistance Rock Type A Shock Factor E Airway Ted E Length E Node Entry Text Primary Layer A Node Exit Text Secondary Layer E Tunnel Type Air Type E Gas Figure 5 8 Clone Attributes Example An existing airway has been set as an exhaust airway with custom primary and secondary layers To copy these attributes on to other airw
219. g a special function in Ventsim to group the data and construct an airway of best fit through the data OPTION 1 Turn on Edit gt Lock on References menu option and select the DRAW button Ventsim Visual User Manual Page 162 15 3 5 Correcting Errors Filtering Tools Simply use the mouse to DRAW airways over the top of the imported graphics The airways will connect to the same position as the reference graphics providing the Edit gt Reference Lock is enabled allowing the ventilation model to be drawn in true 3D coordinates OPTION 2 Convert ANY references to airways Use the Draw Sub Option gt Convert Any This option converts groups of referenced graphics to an expected airway path and may be of use to attempt to convert large amounts of wireframe or multiple string for example floor outlines to an expected airway It is likely that significant editing may be required after using this function to adjust airway locations and correct errors For further information on this method see Convert Any option To quickly sort and validate check the imported airways click on airflow simulation While the model is unlikely to correctly simulate at this stage this function will check the airways for duplicates and unconnected airway ends which will speed up the process of establishing a working model In most cases errors will result from airways not exactly joined into other airways or remaining unconnected a
220. g simulation and the restrict airflow direction flag is chosen for the airway Reversing resistances may be useful in situation where resistance increase such as automatic doors closing or flaps sealing or where resistances decrease such as doors swinging open automatically when airflow direction changes Such setups may occasionally be used to prevent recirculation or assist with emergency response design when fan direction may be reversed If the value is left at zero 0 then a default reversing resistance specified in the SETTINGS will be applied if an airway is reversed AND the restrict airflow direction flag is selected Up to 250 different friction factor presets can be entered or used The friction values in the EDIT box can be applied as presets entered in the preset form as individual CUSTOM values or as AUTO values which defaults to a value specified in the SETTINGS Shock equivalent lengths or shock factors can be entered in the shock preset area The application of these factors will depend on which shock loss method is specified in the SETTINGS The values for each shock item during simulation will be applied according to the method chosen Only the value of the shock loss method currently used needs to be entered Up to 250 different heat moisture and refrigeration sources can be entered Each Heat source can be a combination of different heat parameters such as moisture and sensible heat combined
221. gas yields from different products are mixed proportionally to create an equivalent mixed fuel Note that because of the complex chemistry of fire reactions these values may significantly change in a real mine fire particularly if intense temperatures gt 1000C result in further chemical reactions to combustible products and pyrolised fuel solid or liquid fuel converted by heat into hydrocarbon vapours For example Chasm Consulting has noted actual fire tests in some experiments have demonstrated significantly greater portions 2 3 X yield of laboratory experiments of carbon monoxide can be generated during intense fuel or tyre fires The user is welcome to change the typical laboratory value used by Ventsim to other values if they have information which may provide improved accuracy for their conditions As discussed in the introduction however due to the wide range of assumptions used the simulated gas values must not be used as an absolute determination of likely gas levels in a mine but more as a guide to the extent of gas contaminants and the likely variation between different parts of a mine Heat sources are defined by existing heat presets They could represent diesel machines conveyors electrical equipment refrigeration plants or any other heating or cooling source In addition the Heat Source option allows the temperature of air to be specified passing through the airway This could be used for setting the temperature to kn
222. ge process where heat is removed from one medium usually water or air and exchanged as heat to another medium in a different location If the refrigeration system is surface based and the heat from the refrigeration electrical input and exchange is rejected to atmosphere then only the direct refrigeration component needs to be considered for underground and can be placed where it occurs e g at a surface shaft collar for a bulk air cooler or in an underground airway for a chilled water spray chamber or cooling tower If the entire refrigeration plant is placed underground however then the heat rejected by the refrigeration plant needs to be placed separately as a usually SENSIBLE heat source This heat source needs to include an amount of equal value to the refrigeration value used PLUS the input electrical or diesel power to the plant The ventilation design implications are of course that the heat should not re enter the cooled airflow and sufficient airflow should be available to remove the heat Refrigeration plant design for underground simulation can be summarised with 3 different methods 1 BAC Bulk Air Cooling where all or part of the air entering the mine is cooled on or near the surface The plant is based on the surface and only the refrigerative portion needs to be entered into the simulation BAC plants have the advantage of surface design and heat rejection but the disadvantage of cooling air before it reaches the requi
223. ged when the fan is re loaded or saved As a minimum Ventsim requires at least airflow and a Fan Static Pressure or Fan Total Pressure point Other information such as efficiency or power can be calculated by Ventsim using default settings however it is recommended to enter one of these values if available to enable more accurate power and heat calculations To calculate fan power within a model Ventsim Visual needs either a fan efficiency curve or a fan power curve If neither of these curves is available the default fan efficiency will be used from the Settings menu If both efficiency and power curves are entered Ventsim Visual will preferentially use the fan power curve to calculate absorbed fan power Ventsim Visual User Manual Page 153 14 1 1 Entering Data To construct a fan database from an existing fan manufactures curve follow the steps below 1 Identify the type of fan pressure curve used the fan configuration and exit diameter and the air density the fan curve is established at 2 Divide the curve into up to ten 10 points Do not include the STALL region of the curve in the fan database Entering the stall region of a fan may result in an unstable model simulation at it oscillates between the two pressure and volume flow states 3 Note that less than ten 10 points can be entered if desired however this will increase interpolation errors between points resulting in a less accurate simulation A minimum of f
224. grow rapidly in size plateau at a maximum defined combustion rate and then die slowly to nothing For heat and combustion sources the event scale can be made to linearly interpolate between a starting and ending value 23 4 Use the VentFIRE Function The VentFIRE simulation requires Events to drive the inputs into the simulation Events may be entered into any airway by EDITing the airway and selecting the DYNAMIC tab option Ventsim Visual User Manual Page 209 File Select Airways Tools Airway Fans Heat Contaminant Gas Dynamic Sensors Info Notes FIRE Sta FIRE Pla FIRE Pla Fire and Scenario Simulation FIRE Starts FIRE Plateaus FIRE Plateaus dies Show Graph PE a a i To create a new event click on the NEW button and enter the required information Try to provide a descriptive name and enter a time frame in seconds for the event During this time frame a number of changes can be made to the airway e Up to three combustion source types can be added for a fire e A preset heat source or defined range of preset temperatures can be used e In addition a preset resistance such as a DOOR can be added for this time frame only it will revert to the original resistance outside of this time frame e An existing fan can be turned ON or OFF or the speed changed providing it is present in the original airway e A gas source such as a GAG or inertisation u
225. gs Ventsim Visual User Manual Page 189 20 1 2 Source of 20 2 1 20 2 2 Moisture Model Environmental Settings User Inputs e Blasting Perhaps more of a transient heat source blast can cause short term spikes in heat in a mine and some heat can be retained in broken rock for some time e Oxidisation Highly reactive ores can produce heat when exposed to oxygen Heat Gains 10 019 4 kW Excluding Surface Exhaust Fans Fans 7 Strata 9 Diesel 52 Sensible Sources 20 Autocompression 12 Figure 20 1 Example of Heat in mine calculated by Ventsim after simulation In addition moisture can affect the comfort level of air underground As moisture levels and humidity increase this reduces the ability of the human cooling system sweating to adequately cool the body Strata moist or wet rock surfaces from ground water results in increased evaporation Ponded Water collection of water on the ground or underground dams can increase evaporation of water Diesel Equipment generates additional moisture in the air through exhaust and by work activities by as much as 1 5 5 litres of water per litre of diesel consumed Dust Suppression Sprays used to settle the dust often on main travel routes much of the additional water is eventually evaporated into the air It is important to note that the evaporation of water into the air does not directly increase the heat
226. h allows the survey information to be entered and the resistance or friction factor to be calculated Select the desired resistance method fixed resistance linear resistance or friction factor and select OK to update the model airways Note that if Friction Factor is chosen then an accurate survey of the airway dimensions is required if the factor is to be used elsewhere Applies a gradient or slope to the selected airways The gradient will start from the end selected first in the EDIT box This tool assist in creating ramps between levels particularly if survey data has been entered in 2D and requires to be converted into 3D Distributes rock opening ages evenly along a series of connected airway segments The rock age distribution will start at the end selected first in the EDIT box Ensure that the airways selected do not have split airways into other areas otherwise the function will fail to distribute the ages properly Convert any custom resistance in the edited airways to friction factors and resets the resistance to AUTO Converts any custom linear resistance in the edited airways to friction factors and reset the resistance to AUTO 9 4 Airway Tab Changes made to the airways in the Edit Box are highlighted in BLUE The changes are applied to the airway when e Apply is pressed the Edit Box form will remain open e OK is pressed the Edit Box form will then be close If another airway is selected the changes will be
227. haust emissions For example if Total Carbon TC matter emission rate is given for a diesel engine which includes elemental and organic carbon then the air concentration rates will also be based on Total Carbon Most air quality standards will quote either an Elemental Carbon exposure limit or a Total Carbon exposure limit To convert to an Elemental or Total Carbon concentration a factor will need to be applied either to the original emission rate or to the simulated air concentrations See DPM emissions for further information Gas Performs a steady state gas simulation based on gas settings edited into an airway See the gas simulation section for further information Reverse Contaminant Performs a reverse contaminant simulation where the sources of airflow through the contaminant point are tracked back to the surface The contaminant markers are used to define the point s at which the simulation searches upstream for paths The display and colour legend automatically switch to a source concentration display which shows the relative amounts of airflow along different airway paths which eventually flow through the contaminant marker See Contaminant Source from the menu bar section for further information Find Source Performs a contaminant search simulation which tracks the likely paths of fresh and contaminated air See Location Tool from the menu bar section for further information Recirculation Simulation ADVANCED Ventsim V
228. he Display Manager to show Spread Time The lower corner will show spread times of up to 600 seconds or around 10 minutes E amp Ventsim Visual II Beta Tutoriali vsm File Edit View Savedviews Run Connect Tools Settings Window Help 5 EH aam ECO se PI Hr One ee o A os 5 second 6 T Contaminants Tea gt co von 4 OE O S llcoords 1680 7E 1412 5N 50Z Airsimulation successful Compressible No NVP No airways 132 Ventsim Visual User Manual Page 246 Figure 27 10 Colouring showing contamination spread time in seconds If you got this far congratulations The complete example is available from the Ventsim Visual installation folder under Examples Ventsim Visual User Manual Page 247 27 2 1 Suggested Steps 27 2 Example 2 A skeleton model has been created in a mine planning package by tracing over the existing and planned development and exporting the file as a DXF format file Import this file into Ventsim and adjust it to create a workable model Note that the decline is 5 5m x 5 5m the sub level drives are 4 0m x 5 0m and the ventilation shafts are 2 4m diameter 1 Create an RL reduced level elevation database that separates the mine into each sub level Create a RL that also displays the entire mine 2 Create three PRIMARY Layers and set the DECLINE SUB LEVEL and SHAFT airways to these Layers 3 Divide the mine into fresh exhaust air with the DECL
229. he display The new window is based initially on the view position and contents of the most recently used open window 5 9 3 Zoom Out Increase the distance away from the window point of focus This may be of use if the mouse used does not have a scroll wheel 5 9 4 Tile Enables windows to automatically arrange to fill the master window form Note that only docked windows within the master window will be affected Vertical Tiles all open windows in a vertical direction with equal spacing Horizontal Tiles all open windows in a horizontal direction with equaly spacing Tiled Tiles all open windows in square or tiles to fill the master window display 5 9 5 Auto Arrange Enables windows to automatically dock and arrange the window position within the master window Windows that are dragged into the master window will be automatically arranged when this function is activated Ventsim Visual User Manual Page 69 6 1 1 Fit All RA Solid Wirefr 3 Grid Nodes Icons Arrows References Limit Data ER ei a h g d 6 THE VIEW TOOLBAR The VIEW toolbar adjusts the display of items shown on the screen Fits available graphics centrally on the screen If graphics are spread over a huge area then Ventsim may elect to only show the airways in the most prominent area Switches the model between wireframe and solid display mode The wireframe mode is sometimes useful for fine editing of models particular whe
230. he elevation of the airway and surface rock temperature settings The total sensible dry heat addition to the airway from rock strata and any user sensible heat inputs into the airway The total latent wet heat addition to the airway from rock strata and any user latent heat inputs into the airway 9 8 Notes The Notes Tab allows detailed information to be recorded for any airway Ventsim Visual User Manual Page 113 Sensors Info Notes Airway Notes Airway surveyed in February 2012 after rockfall Figure 9 14 Recording sheet for entering general airway information Notes may include specific model setup information or may consist of ventilation survey results of airflow temperatures or gas levels for actual underground ventilation conditions Such information could be used to help validate simulated models or could provide a useful ventilation recording tool to demonstrate ventilation conditions underground over a period of time or provide a Statutory record of ventilation information Add Ventlog Station Adds a Ventlog compliant name to the airway notes A Ventlog name in the notes field will indicate that the airway is a Ventlog station that can be exported to a Ventlog database The default name starts with LOG however the name after this text field can be changed to any valid text name representing the name of the station For example Ventsim may automatically name the station LOG VS50 however
231. he main Ventsim window The direction of tiling can be changed in the Window Menu bar in Ventsim These windows are called Docked windows because they are constrained and sized by the main Ventsim window Additional windows created after the first four will be undocked and can be independently sized and located around the computer screen s A docked window can be undocked simply by dragging the window outside of the main Ventsim window An undocked window can be re docked by dragging the windows back inside of the main Ventsim window providing there are less than four windows present To disable the automatic docking behaviour deselect the Auto Arrange function from the Window Menu Bar Shared Ventsim functions such as the Camera button or keyboard button inputs are always directed to the currently active window The Active Windows is the most previous window clicked or interacted with the mouse It is possible to construct an airway between windows While in the DRAW mode simply start drawing in one window click at least one leg of the airway in the initial screen then drag the mouse to the new window and location Ventsim Visual User Manual Page 26 4 3 User Control Summary Middle Mouse Button Wheel Right Mouse Button Scroll Zoom in out of model Hold amp Drag Up Down Tilt Model Scroll Shift Move Edit Plane Elevation up Hold amp Drag Left Right or down Spin Rotate Model Hold amp
232. he mine The vent officer directs emergency personnel to that area who find a large number of smouldering rags in an industrial waste bin Contaminated Air Potential Source Figure 17 1 Example of contaminant sourcing narrowing down a smoke source Ventsim Visual User Manual Page 176 17 7 Fire Simulation For intense or hot fires it is not recommended to use the contaminant functions for fire simulation Hot fires produce significant expansion of airflow and natural ventilation pressures which can change flow quantities and even directions thereby rendering conventional contamination simulation models inaccurate For small fires or perhaps the initial phases of a larger fire contaminant distribution may still be a useful way to model smoke concentration and direction through a mine For larger fires it is recommended to use the Ventsim 3 0 Premium VentFIRE function which has specific simulation methods for distribution of hot gases smoke and heat from fires and can assist in simulating the dynamic changes to the ventilation system Ventsim Visual User Manual Page 177 18 DYNAMIC SIMULATION Advanced Dynamic simulation is a specialised simulation method that shows a time based simulation result that can be dynamically viewed and changed during the simulation Dynamic simulation can be applied to contaminants gases DPM and heat Reset Events The key difference between steady state and dynamic simulation
233. he order of airway numbers in a Ventsim Visual model Ventsim Visual User Manual Page 65 5 7 4 5 7 5 5 8 1 Resequence Index Unique Numbers Troubleshoot Restrictive Fans Unnecessary Bulkheads Reset Model Presets Index numbers are dynamic numbers representing airways stored internally in Ventsim Visual The numbers may change as airways are deleted or added Ventsim Visual uses Index numbers to refer to airways during simulation and when identifying problems All index numbers are sequential and the highest index number will be the sum of all airways Resequencing index numbers renumbers all airways from higher elevation to lowest elevation easting to northing Unique numbers are static numbers which do not change when airways are deleted or added Numbers are sequenced incrementally from the last highest unique number As such as airways are added and deleted there may be large gaps of numbers between airways Unique numbers are a useful reference to identify the same airway as the model is developed Resequencing the unique numbers renumbers all airways from number 1 sequentially top to bottom to the last airway HINT Resequencing numbers is not a requirement in Ventsim Visual but may simplify tracking airways as the resequence function tends to group airways in similar locations with similar numbers This is particular handy in the SPREADSHEET function which initially lists airways in sequential index ord
234. he pre existing calculated values Ventsim Visual User Manual Page 107 9 6 6 Contaminant The contaminant tab display options and settings required for contaminant simulation in a model 38 EDIT 1 airways 100 0 m Lezl lr File Select Airways Tools Airway Fans Heat Contaminant Gas Dynamic Sensors Info Notes ON Activate Contaminant Contaminant Contaminant Concentration 0 CO ppm Dynamic Contaminants Fixed Rate Linear Decay 3500 Second Logarithmic Decay Explosives 500 kg Moderate 4 Sourcing Location Tool Report Smoke Report Fresh Figure 9 11 Edit Box Contaminant Input Contaminant Places an initial average contamination value into the airway The value can either be unit Concentration less or represent a volume concentration value of a particular type It is proportional to the airflow in which it is entered and could be considered as a percentage part per million ppm unit or any other unit which is representative of a value per unit volume of air Clicking on the check box adjacent the value box will automatically set or remove a value specified in the Setting defaults This value is ignored if Explosive Simulation is selected as in this case the initial concentration is automatically calculated from the explosive yield rate established in the settings and the airflow 9 6 7 Contaminant Specifies dynamic contaminant simulation options which can be modified for the airway Options D
235. he pressure may actually be negative if the fixed flow forces the airflow to be lower than would otherwise simulate effectively resulting in the fixed airflow acting as a higher resistance Hint Ventsim Visual limits fixed airflow pressure build up to around 50 000 Pa Pressures beyond this can result in serious model imbalances and heat build up and in most cases are likely to be erroneous in nature anyway for example an airflow fix may be forcing air through a very high resistance Ventsim Visual will raise a simulation error in this case to warn the user of unacceptable pressure build up This can normally be easily fixed by finding the restricting airway Ventsim Visual User Manual Page 164 15 4 3 15 5 1 Estimating Fan Pressure Requirements Fan Air Density Fixed Pressure Ventilation Pathways In all cases the results of a fixed flow can be observed from the Edit Box information function which describes the pressure and power or resistance required to produce the flow This can be directly used to estimate a fan duty point which would be required to produce the same results This fix pressure can be equivalent to Fan Static Pressure or Fan Total Pressure depending on the simulation type and location of fan Fixed Flows are often used to help estimate required fan pressures The Pressure given for fixed flows will be an estimate of the Collar Total Pressure e the total pressure of the airflow in the airwa
236. here an airway age is entered as a time value such as 3 5 years the Current Year value is ignored HINT Where true airway ages have been entered as a calendar year within a model the Current Year setting is useful for ageing a mine and determining future cooling requirements Heat flow from virgin rock strata decreases exponentially over time as the rock is cooled and future cooling requirements can potentially be lower than current cooling requirements as a result The rate at which rock increases in temperature at depth This is assumed to be a linear value Geothermal gradients show significant differences at different points around the earth and can be as low as 1 degree Celsius per 100m to more than 10 degrees Celsius per 100m This value should always be adjusted to suit the conditions at or near your mine Ventsim Visual User Manual Page 137 HINT In some cases the temperature gradient may not be close to linear particularly in near surface portions of the mine The near surface rock temperature may be influence heavily by climatic conditions on the surface The best approach is to calculate to gradient over the unaffected deeper underground portion of the underground mine which a subject to the majority of heat influence and project this temperature gradient to the surface elevation Enter the Surface Rock Temperature setting as this calculated value not the true surface rock temperature Copper Ore body Carb
237. herwise future simulation will be permanently affected by gas through a model until the gas it cleared out and removed with the clear contaminant option Ventsim Visual User Manual Page 188 20 1 1 Sources of Heat 20 THERMODYNAMIC SIMULATION Advanced Ventsim Visual Advanced Thermodynamic or heat and moisture simulation is a complex field of mine ventilation and environmental engineering A comprehensive understanding of psychrometry as well as practical aspects of heating and refrigeration is recommended before using Ventsim Visual to assist with major infrastructure decisions for mine planning and developrnent 20 1 Introduction Heat in mines is an inevitable part of mining in the earth s crust at depth As mines become deeper excessive heat may play an increasingly more important part in the consideration of a ventilation system design Conversely cold conditions particularly in far northern mines can equally affect a mines performance especially in winter where freezing of shafts and collars and worker discomfort underground become a problem The impact of heat on worker physiology is perhaps the key factor in designing a ventilation system for underground mining that is impacted by adverse temperatures The exposure of excessive heat to workers impacts both on their work performance and output and ultimately their health and safety When designing a ventilation system in addition to providing ventilation to
238. hical data found in the reference file Adds the imported data to any existing referenced solid graphical information already within the model Adds the imported data as a wireframe line solids instead of a polygon solid Most imported files do not have an internal specification of whether the units are Imperial or Metric Ventsim will assume the coordinates are the same as currently used in the Ventsim file however if the coordinates system are mismatched then the imported data will be displaced to incorrect coordinates for example a metric DXF imported into an imperial Ventsim model This setting allows you to override the default Ventsim setting to ensure coordinates will match up Allows a DXF file to be imported with an offset from the original file coordinates This may be useful to match existing coordinates used in Ventsim or when a 2D file single elevation file needs to be moved to a new elevation in Ventsim Flattens the entire DXF file on to a single elevation or level Occasionally flat 2D CAD files may have different elevations set in the file When these files are used in a 2D CAD package the elevations difference may not be noticed however when loaded into Ventsim the elevation differences may become troublesome in a 3D working environment If the OFFSET Z option is entered then the imported elevation will be at this number when this option is set Allows the DXF import data to be scaled to a different size This is som
239. hould be reasonably accurate if an exact fan pressure and flow curve is required for fan performance at different revolutions it is suggested a separate manufacturer guaranteed fan curve be entered for the adjusted variation The fan duty point defines the pressure and airflow that a fan operates at and is shown by blue lines on the fan curve Note that either an individual fan duty can be selected or if multiple fans are present at the installation in parallel or series configuration the entire combined installation duty can be displayed Due to local air density adjustments the fan curve may have been adjusted to the one defined in the Fan Database The efficiency returned reflects the efficiency curve entered with the fan The efficiency curve is the shaft efficiency of the fan It does not include electric motor or drive inefficiencies which are considered separately in the Settings menu under Motor Efficiency Enters the fan database screen to view or adjust fan data Note that any fan changes will not be reflected in the EDIT box until after a simulation Also note that modifying the fan database will change ALL fans of the same name in other locations in the model To create a custom change only for the fan at one location you will need to create a duplicate of the fan in the database and only modify the duplicate Hint Fan operating density is an important specification for designing fan types and installations Higher air densities
240. ial energy difference of the change in elevation of the hauled rock This can be calculated as a percentage of the mechanical output of the diesel engine and will reduce the amount of heat input into the model In most cases this will only be a small fraction of the diesel engine power and in most cases can be ignored The diesel fuel calculator provides an alternative way to calculate engine power within a ventilation model overcoming the need to estimate engine utilisation It calculates diesel engine power by using the calorific heat value of fuel and back calculating engine power using the diesel efficiency setting in Ventsim by default 35 Heat Assistant eh Sam Air 1 Air 2 Diesel Eng Diesel Fuel Water Chil Engine Input Data Fuel Usage 35 ten Potential Energy Conversion 5 Estimated Diesel Heat How Diesel Engine 314 0 kW Sensible Heat 888 4 kW Latent Heat i A Accept Cancel Figure 13 4 Diesel Fuel Consumption Assistant By entering the average fuel usage of a diesel engine Ventsim Visual can calculate the equivalent average engine output for use in the model If this value is derived from actual engine diesel fuel usage of a particular unit in operation many modern machines automatically record average fuel flow this therefore already includes time the machine is not operating at full capacity As with the previous tab a portion of the diesel engine power can be included as
241. iate airway is assumed to have cooled close to a long term air average and the fire simulation assumes a rapid transfer of heat from the hot air back into the cooled rock mass To facilitate this rapid transfer the rock must be assumed in the Gibson s heat transfer algorithm to be freshly exposed again Note A default value of 60 seconds is suggested which provides rapid absorption for intense heat changes Values lower than this can cause over prediction of heat absorption of very hot air For non fire dynamic simulations heat calculations can sometimes slightly exceed steady state estimates If dynamic simulations are required to closely match steady state simulations it is suggested to increase this value substantially the second equivalents of days weeks or even months The thickness of rock which is directly influenced from short term dynamic heat changes This method allows an exposed surface rock layer of skin to both store and release heat from rapid heat changes While actual rock in this situation will theoretically build up a complex graduated heat profile based on changing heat and air velocity this simplified method assumes a single homogenous rock mass skin that absorbs heat evenly but beyond which no significant heat passes For short term dynamic simulation this is a reasonable assumption INFO As this skin layer heats and becomes closer to the temperature of the heated airflow the rate of heat
242. ics This toolbar can be hidden or moved to the left or right of the screen 5 Display Manager Contains controls to alter the colour or transparency of airways on the screen In addition it can also change the display to show different layers levels elevations or air types on display 6 Data Position Control Selects the position along an airway from which data will be displayed as text on screen or as colours The condition of air will change along an airway particularly long or deep airway segments therefore this option is available to select which position along an airway segment display data is sourced from The first and last button displays the conditions of air entering and exiting an airway segment The middle button displays an average of airway data through the segment The middle left and right button displays the airflow conditions entering and exiting any icon for example a fan within the airway If an icon is not present then the middle conditions of an airway segment are displayed 7 Mouse cursor position coordinates in the 3D screen 8 Simulation status Green successful simulation Yellow successful simulation with warnings Red unsuccessful simulation 9 Main 3D view display window Up to seven 7 separate windows can be opened in Ventsim The first four 4 windows can be docked within the main windows structure while the remaining are undocked or free floating The success on how to utilise some of th
243. ienced in different parts of the mine and for how long those temperatures may exceed a certain threshold Once again VentFIRE can be used to e Dynamically vary the location and output of diesel equipment during the day e Dynamically modify what auxiliary or booster fans may be turned on or off e Monitor the effects of these changes on air temperature at different working locations around and downstream from the activities 23 2 Preamble on Fire Simulation No underground hazard has greater potential for large loss of life than a mine fire or explosion The smoke and gases produced by such an event in a confined space quickly creates a lethal atmosphere for any underground workers exposed to the event For this reason there is great interest in being able to predict the effects of underground fires and utilise the results to establish emergency response procedures and systems to ensure the safety of people working underground Unfortunately the prediction of fires before the event is extremely difficult not only the location which to some degree may be predicted using risk assessment techniques on possible combustible sources but also to the nature size and behaviour of the fire For example a truck fire could be caused by engine turbo failure hydraulic line failure onto hot exhaust electrical short circuits or a hot tyre In each case the fire may be contained within the immediate portion of the truck or it coul
244. iesel engine is GAP RA P Diesel Power AS Efficiency Airway segment divisions for heat calculations The heat simulation process in Ventsim Visual progressively calculates heat along each airway by dividing it into smaller sections Where airflow is very slow or an airway is very long this allows the psychrometric process to continually adjust pressures temperatures and moisture content resulting in a more accurate simulation Ventsim Visual automatically adjusts the number of divisions according to airflow velocity airway length and heat inputs The number of divisions used is restricted by the min and max values in the settings Higher division values will theoretically give more accurate heat estimates but will increase the time required for simulation Performs multiple airflow and heat simulations When set to more than one 1 performs multiple heat and airflow simulations adjusting densities and airflows between each simulation Manually pressing the HEAT simulation button has the same effect Heat simulation in Ventsim Visual Advanced is performed as two discrete simulations first as an airflow balance followed by a heat balance simulation While the mass flow balance from the airflow simulation is kept constant during heat simulation the new temperatures and air densities calculated after heat simulation result in a theoretical mass imbalance of airflows This can be corrected by a subsequent airflow simulation howeve
245. ightly conservative system pressure and airflow if fan exit shock losses are modelled identically for both an FSP and FTP case When designing a model this may be advantageous to provide contingency for design simulations In addition use of FSP curves is less reliant on accurately modelling fan exit shock losses and provides a greater contingency for design airflow In general they may be more suitable to use for a less experienced user The case for Fan Total Pressure FTP Simulation FTP Simulation will allow Ventsim Visual to utilise the full fan total pressure curve for model system pressures Provided fan exit shock losses are modelled to consider the fan installation and exit airflow orientation then this method should provide more accurate results In addition as Ventsim Visual will consider system exit velocity pressures allowing fan exit diameters airway surface exhaust sizes or evas s sizes are adjusted to simulate the effect of on surface exhaust airways and mine system pressure Note Increasing fan diameters or including diffusers in Ventsim Visual for underground installed fans will have no automatic effect on model simulation results as it will not change the surface velocity pressure exit losses It may however decrease shock losses at the fan exit which if modelled in Ventsim Visual by changing airway shock loss will result in improved fan performance Evas Diffuser Hint If the Fan Total Pressure Method
246. ill display indicating a possible conflict CAUTION When selecting REPLACE many components such as fan databases levels and most presets may not correctly map to the existing model s fans levels and presets particularly if for example fans within the database are in a different order These may need to be manually corrected by checking and re editing fan airways to ensure the correct fans have been placed The start up settings for Ventsim Visual The defaults file is stored in the user s personal Windows directory The file is loaded when Ventsim Visual starts and specifies the settings behaviour and fans when the program is first loaded Each user who logs on to the computer will have a different default file which is initially created when the program is installed Ventsim Visual files have a copy of defaults stored within the file which may have been modified after the model file was started This will override the standard start up defaults when the file is loaded Reload Startup Reloads the original defaults file that is first loaded when Ventsim is initiated This may be required if the default settings that are automatically loaded with a Ventsim simulation file are incorrect or out of date or you wish to overwrite the current file settings CAUTION This will reset all file parameters such as fan databases and graphics options If you wish to only update selected components use the inherit function to l
247. imations made in calculating heat and airflow in a mine Airflow simulation approximates flow in each airway to an acceptable error while heat simulation approximates temperature to an acceptable margin These errors and margins are adjustable in the settings The summation of these approximations can cause minor variances between heat entered or removed from each airway and the heat difference between the air entering and exiting the mine The heat audit function is designed to highlight these potential differences and show the potential effect on simulation accuracy It depends on the model and tolerance for temperature margins however up to 5 is generally acceptable and will only give a slight imbalance in temperatures Errors beyond 5 are likely due to excessive airways in the model with little or no flow which have a relatively high degree of approximation error In most cases the error can be reduced by EXCLUDING unused parts of the model with little airflow reducing the mass flow limit in the heat simulation settings or reducing the temperature error in the heat simulation settings A selection of graphs derived from model parameters The energy losses show the loss of input electrical energy into various ventilation losses such as wall friction shock loss and exit losses Exit losses represent power lost due to the velocity of ejection of exhaust air into the atmosphere Note that some of this energy can be recovered and converted to
248. imulating this will produce the same results Redo will reverse the result of the undo function Copy airways from one Ventsim Visual program to another Copy and Paste Airways creates an exact replica of selected existing airways in a model and pastes them into the same location into the existing or new model The function is primarily designed to copy and paste airways between Ventsim files or between different Stages in a mine ventilation design for example to update airways from a model that has been modified To use this function to copy and paste between models ideally have two copies of Ventsim Visual open with different model files Select the Copy A rways menu item and click on or fence the airways you wish to copy To paste the airways move to the new model or load it up and select the Paste Airways TRUE menu item The copied airways will be pasted into the new model at the same coordinates as the original airways To paste duplicate airways between STAGES use the same technique but simply copy the airways in one stage switch to the desired stage name or number then Paste Airways TRUE A copy of the airways will be set in the new stage If airways become duplicated in the process Ventsim Visual will delete one of the duplicate copies To paste airways in a different location use the Paste Airways LOCAL menu option This will paste the airways around the current local screen location set in the view window ef
249. imulation Frequency 10 if required e Ensure your model is properly balanced and simulating correctly both steady state air and heat simulation before fire simulation e Optionally the model can be stripped of previous simulated results by selecting RESET EVENTS Note that Ventsim will automatically remove previous gas and contamination results before a new simulation anyway Fire Sim Multi Sim Options Explosive Sim List Events Smooth Data Reset Events Record Video gt Once all events and monitors have been placed a simulation can be performed by pressing the button for VentFIRE simulation or selecting the RUN gt VentFIRE gt FIRE SIM option from the main menu A Fire Sim simulation will perform simultaneous dynamic simulation on airflow heat and gas Other combinations of simulation can be selected from the Multi Sim option The simulation type performed will default to the previously selected simulation type so ensure the sub option has selected Fire Sim simulation if this is the type of simulation required Ventsim Visual User Manual Page 214 23 6 4 23 6 5 23 6 6 A dynamic simulation will provide a time based simulation result with screen updates showing the simulation result at a displayed time Fire Simulation 00h 04m 05s 000ms The screen graphics will show the current results on the simulation with colours and text showing simulation progress During a dynamic si
250. imulation is a subset of contaminant simulation with sore specialised properties to allow for multiple gases and air density estimation based on gas composition This can have application for natural ventilation changes for simulation 19 1 Introduction Gas Simulation is based on the same linear spread algorithm as other contaminant simulations however it allows for the simultaneous release and distribution of up to 15 different gas types and automatically volumetrically balances other gases to ensure a 100 total concentration mixture is maintained This function may be useful when tracking multiple contaminants of different levels from different sources or when the density effects of different gas types need to be modelled in a simulation Gases can be placed in models using an injection method an inline gas concentration method or by using a gas emission rate The first two methods use the same type of simulation however the construction of the airways in Ventsim differs The last method emits gas along predefined airway routes Specifically sets the concentration of gases in an airway and distributes the gas concentration downstream All air entering the set airway is reset to the specified gas concentration This method would normally be used when a known or measured concentration of gas is present in an airway Ventsim Visual Examples coalmine vsm Example Coal Mine FF Run Tools Window Help EE G DPE HUT
251. imulation which defines the total amount of diesel particulates emitted by an engine over a period of time for each unit of engine power This can be derived from manufacturer s specifications or by practical testing of exhaust emissions Note that EPA measured values are likely to include all particulate matter including elemental carbon organic carbon and other trace matter Atmospheric DPM exposure limits are normally limited to elemental or total elemental organic carbon levels therefore either emission rates or final simulated results will need to be scaled accordingly Ventsim Visual User Manual Page 105 Advance Rate The rate of advance or progression of the airway per month The area size of the airway dictates the number of tonnes entered into the simulation and this figure is included in the Simulation Summary Heat from broken rock entering the mine atmosphere is highly dependent on the geometry of the muck pile the length of time the rock is exposed to air and the airflow and moisture over the muck pile To simply the process heat from broken rock is added to the atmosphere at a rate defined in the settings as a percentage of heat contained in the broken rock that is between the mine atmosphere temperature wet bulb and the virgin rock temperature The exposed rock surface of the advancing airway is automatically assumed to be freshly mined for simulation purposes 9 6 5 Rock Conditions Sets specific rock conditions for th
252. inally add fans ventilation controls and stoppings to direct airflow through the model Limiters Ranges r IC Hide Transparency Custom VentDuct Custom Exhaust Fresh Not Set Figure 27 16 Fresh and Exhaust Air Type colouring 18 To limit the view to the decline or shafts only using the layer control in the display selection to control which layers are displayed e Ventsim Visual H Business Ventsim InstallsVV Files Sims Tutc K l2 vsm Example 2 Tutorial File Edit View SavedViews Run Tools Window Help 106441240909 Jugen IPsa OOOORS I Units m3 s Coords9862 1E 11198 4N 10997 Ventsim Visual User Manual Page 251 4 Ventsim Visual H Business Ventsim InstallsVV Files Sims Tutorial2 vsm Example 2 Tutorial File Edit View Saved Views Run Tools Window Help beaaa gt 1904 200090840I0 Delete ES Plan lso Section EW Section NS Shaft View i Units m3 s Coords 8402 3E 111014N 1099 Z Figure 27 17 The final DXF import result showing the decline and the exhaust shafts displayed independently with layers 27 3 Example 3 Import a Complex Mine Design A centreline model of an entire existing mine has been A venis Via Cien Coria ion Hal created in a mine planning package and exported to fie tat view Savedviews Run Tools Window Help Ventsim Import this file into Ventsim and adjust itto uo Uli RDI DE create a workable model Import the DXF model in
253. inated air If a fresh air sourcing pin is placed all airways upstream will be turned blue for fresh air Once all entries and exhaust pathways to the mine are marked similar airways can be selected and the air type for those airways could be changed to Fresh or Exhaust or Intermediate etc 9 3 Edit Box TOOLS Menu Ventsim Visual User Manual Page 91 9 3 1 9 3 2 9 3 3 9 3 4 9 3 5 9 3 6 Tools Set Fix Flow Resistance Orifice Pressure Survey Tools Apply Gradient Slope Distribute Rock Age Convert Fixed Resistance to Friction Factors Convert Linear Resistance to Friction Factors Where a fixed flow has been used to retard or resist normal airflow the resulting resistance can be used instead of the fixed flow Select this option to convert the fixed flow into a custom resistance or an orifice size that will give a similar flow based on current model pressures If multiple airways are selected then all selected fixed flows will be converted to resistances or orifices The fixed flow is removed once this action is done Pressure surveys of airways or shafts allow more accurate resistances to be calculated and used in Ventsim These options provide tools to convert differential or barometric pressure survey information into resistances or friction factors Select the airways along which the pressure survey was performed and select the menu option A dialog form will show whic
254. ine 22 1 2 Example 2 Multiple Options 22 1 3 Example 3 Totally different models A user may want to build a model showing the initial decline development phase of the mine complete with ventilation ducts and auxiliary ventilation from the surface Next an intermediate phase is required show decline development complete and primary shafts in place with the surface auxiliary duct now removed but no production activities shown Finally a model is required representing all production activities For this example the user can create three stages Every airway in the model can belong to one or more of the stages For example the surface ventilation auxiliary duct system would belong only to Stage 1 initial development however the initial main decline would belong to all three stages because it does not change The second stage would include the main shafts which belong to both Stages 2 and 3 but not Stage 1 Finally the production development and activities would belong to only Stage 3 Different stages can be selected and displayed from the stage menu in Ventsim O DI Initial Development W Preliminar Pre Production Production A consultant wishes to show a client three 3 different ventilation options for a mine design Option 1 has a large shaft design with a single high pressure fan Option 2 has two smaller shafts located in different areas with two smaller fans Option 3 has the two smaller shafts
255. ing Ventilation to Ducts When duct is created a pathway will be built into the duct to allow it to draw and deliver airflow to the underlying airway To ventilate a duct simply EDIT the start of the duct airway with the EDIT toolbar button do not SELECT the duct first as the entire duct will be selected and then use the FAN tab to place a fan or a FIXED flow in the duct Ventsim Visual User Manual Page 171 ras Clemcorp CC1254 Mk3 1X55kW GV1 Inlet Stage vii E Options Fan Configuration TP 9 9 Parallel OFF Fix Flow 11 5 m s Series Limit Flow 11 5 m s Self Close Fix Press 0 0 Pa 100 RPM com 1x Fans Air density 1 21 kg m3 mm 100 1485 rpm Duty FTP 1 350 6 Pa Quantity 29 7 m3 s 31 2 m s Eficiency 90 2 Power 48 2 kW shaft 50 8 kW electrical Cost 44 435 Individual Fan Data 9 Combined Fan Data Pressure Efficiency Power Figure 16 2 Auxiliary ventilation of duct 1893 1704 BESSSESS55 1325 V g 1136 Pressurised or Suction The direction of the fan controls whether the duct is pressurised or in suction To change Duct the direction of the installed fan after placement simply use the REVERSE toolbar button to change the direction of the fan section of the duct The entire duct airflow direction will then reverse after the next simulation Inline Fans If a duct has multiple fans installed at different positions a common prac
256. ion Fans Heat Contaminant Gas Dynamic Sensors Info Notes Figure 9 1 Edit Box Tabs 9 1 Edit Box FILE Menu 9 1 1 File gt SNAPSHOT Creates a picture of the current airway information This picture can be saved by right clicking the form or used to compare results with an updated simulation 9 2 Edit Box EDIT Menu 9 2 1 Select Airways Allows the selection of multiple airways based on a selection criteria Multiple selected airways can be edited simultaneously from the Edit Box The number of airways selected will be displayed in the form Caption Box at the top of the form Select Joined Airways Selects all airways directly joined to the initial airway for example a decline loop The selection will stop when the airways reach a junction Ventsim Visual User Manual Page 90 Select Same Primary Layer Select Same Secondary Layer Select Same Size Select Same Resistance Type Select Same Friction Factor Type Select Same Shock Type Select Same Fan Select Same Air Type Select Same Heat Type Select Loose Ends Select Both Loose Ends Select Same Contaminant Type Selects all airways with the same primary layer Selects all airways with the same secondary layer Selects all airways of the same size Selects all airways with the same resistance type eg bulkhead This may be useful for group changing and testing different regulator types on model performance Selects all airways with the
257. ion may remain largely hidden or ignored The total cost of ventilation in mines should be considered as a combination of costs e A direct operating cost such as power consumed or maintenance and upkeep of ventilation system and e A direct capital infrastructure cost which includes the development and infrastructure mined and fans purchased and e An indirect cost which factors productivity gains and losses due to good or adverse ventilation conditions When ventilation costs are viewed as an integral part of all production activities the cost of poor ventilation becomes even more substantial and can be used to justify additional investment in the ventilation system Ventsim Visual includes a number of tools to quickly analyse and help reduce ventilation costs 26 1 Financial simulation Advanced Versions This function is designed to quickly estimate optimum ventilation infrastructure size by considering mining costs as well as life of mine ventilation operating costs Financial simulation can help optimise airway sizes and save substantial money over the life of a mine Keep in mind however when using estimated mine life to optimise an airway size that in many cases mine life extends far beyond initial estimations as further ore resources are found Many mines are stuck with an inadequate ventilation system that is stretched far beyond its useful life because the possibility of mine extensions or expansions was not con
258. ion of 10 or 20 which may take a long time may help resolve this instability Heat Iterations Limits the number of internal iterations permitted by Ventsim Visual to converge and find an acceptable heat solution Where recirculation occurs or high numbers of very low airflows are present a simulation may take a large number of iterations to fully balance In most cases the main airflows will quickly balance and even if the simulation fails to complete within the set number of iterations this will usually be in the low flow airways which have little effect on the main flow airways The status bar at the base of the Ventsim Visual window will show the progress of a heat simulation including the number of iterations and the heat balance errors Increasing the number of iterations may help resolved unbalanced models but will take longer to simulate HINT A leading cause of heat flow convergence issues is recirculating airways in low flow airways due to natural ventilation pressures Natural ventilation pressures can create internal eddies of air in disused or low flow airways which can affect heat simulation convergence To prevent this and speed up heat simulation either turn off natural ventilation simulation if natural vent pressures are not significant or block disused airways so they simulate as no flow Water to Diesel Ratio For diesel heat sources this value defines the amount of water emitted to the air as latent heat is per un
259. ional heat required to reverse the airflow Additional heat is absorbed by the surrounding rock mass of the airway very quickly and this can contribute further to a choked balance condition In the case of a choked airflow this is a complex and potentially unstable scenario which in reality may or may not reverse in a mine It can be dependent on complex three dimensional fire behaviour that can only be analysed using computational fluid dynamics CFD type analysis For example a fire that produces zero net airflow in Ventsim will be quickly assumed by VentFIRE to be throttled with insufficient oxygen In reality a bidirectional flow pattern may be established where fuel rich oxygen deficient hot air travels in one direction away from the fire near the roof while oxygen rich fresher air continues to travel to the fire at floor level in the other direction Such behaviour is beyond current VentFIRE capabilities however to test this scenario in VentFIRE the user is welcome to change the oxygen dependent setting in the EVENT sheet that will prevent the fire from being throttled in the event of insignificant oxygen Another less extreme option is to adjust the residual heat setting in the SETTINGS gt DYNAMIC simulation to provide a continued source of heat eg 50 of maximum combustible rates in the event the fire is throttled below this point Finally A further option is to decrease the frequency of air simulation du
260. ions are provided on the settings page It is recommended the sensor information first be observed for valid data as incorrect or unreasonable data may cause the simulation to fail or show unpredictable results cas ula 3 Sensors Date From 01 01 1900 12 00 Date To 31 12 2014 12 00 Automatic Sensor 10 Update Simulation V Airflow Simulation V Gas Simulation Heat Simulation Log File Full Log File Mini Automatic Update Frequency fo Validate Connections Date From To The date fields can be checked to import only data from a specific time and date This assumes that multiple identical sensor readings are available in the data file from different dates If this remains unchecked then only the most recent sensor data will be shown Manual Auto Update The sensor data can be set to import into the model only once or periodically at set time intervals If Auto Update is selected then the user may note that Ventsim will pause momentarily whenever the data is imported Simulation Options The data can be used to simulate conditions within the Ventsim model Use these settings with caution as incorrect sensor settings can seriously affect simulation results and invalidate the Ventsim Ventsim Visual User Manual Page 226 24 4 2 IMPORT and MODIFY SENSORS model with incorrect data The sensors must be set to allow simulation individually otherwise these settings will be ignored
261. ired A Ventsim text file must have at least the first row header line which defines the text file as Ventsim compatible and a Completion line END the last line in a Ventsim Visual saved TXT file Load any Ventsim file saved as a TXT file to view the structure in a compatible editor for example Microsoft Excel 4 MINEDESIC Entry Node Exit Node Branch NaiError Mess pathways X1 Width Height 1 Multiplate Arch 2 Tf95 Surf Main Shaft 3 TVR Surf Temp VR 4 Surf Rb82 60 Rb82 Rb82 5 1235 5 477226 5 477226 1233 1200 SZ Decline Fowler Shaft 4 4 1 1 1 1 1 4 4 60mLv Access 1 Sa50 Surf Sa50 1 Temp VR 1 4 4 4 4 4 4 4 4 4 4 4 21 60 Rb82 22 60 Rb82 23 Figure 5 3 An example of a Ventsim Visual Text File Loaded into Microsoft Excel Ventsim Visual User Manual Page 39 Import DXF DWG Imports DXF DWG Datamine and Surpac formatted data supported by many CAD and DM STR Mine Planning packages Importing graphics items can serve two functions Importing line string graphics can allow Ventsim Visual to directly create new airways using the line strings as centre lines for the development The centrelines can be converted to airways during the import function or later on by selectively clicking or fencing the centrelines with the Add gt Convert function Further utilities under the tools menu allows users to quickly turn the new airways into viable models HINT
262. irflow and pressure balancing using the Hardy Cross method Resolution Ensure that there are not too many airways connected to the SURFACE In addition ensure that airways are physically connected use the TOOLS gt FILTER option if necessary to allow Ventsim to ensure a connection Ventsim Visual User Manual Page 275 33 APPENDIX F Shortcut Keys A number of keyboard strokes exist to assist in rapid selection of commonly used functions Most menu items have the shortcut key next to the menu item Below is a general summary of common key strokes CTRL N New File CTRL O Open File CTRL M Merge File CTRL I Inherit File Attributes CTRL S Save File CTRL F File Note CTRL C Clone Attributes CTRL V Apply Attributes CTRL L Lock On Target Toggle CTRL T Lock On Transparency Toggle CTRLQ Quick View LEFT Arrow Move to previous Quick View RIGHT Arrow Move to next Quick View HOME Fit All INSERT Insert Node PAGE UP Select Move Up one elevation level if defined PAGE DOWN Select Move Down one elevation level if defined END Show ALL elevation levels DEL Enter delete mode select fence airways to delete BACKSPACE UNDO CTRL Z UNDO TAB REDO F1 HELP F2 Plan Section Views Toggle to cycle through views F3 FIND Toggle to repeat last find command F4 FIND and HIGHLIGHT found airways F5 Simulation Airflow F6 Simulation Thermodynamic F7 Hide Show Zero Flow airways F8 Hide Show Excluded airways F9 T
263. irway may inadvertently join into the adjacent airway creating shortcuts or duplicate airways Sets the viewing system to orthogonal or perspective Orthogonal removes the effect of perspective making objects in the distance appear the same size as close objects This mode may be of assistance when viewing sections or plan views where the perspective appearance would otherwise distorted the true scale of objects at different distances The mode has the disadvantage of a more cluttered and complex display Perspective view is more suited to general editing and viewing where objects in the distance are obscured by perspective scale creating a less cluttered display Ventsim Visual User Manual Page 75 r gt vi Ventsim Visual El _ File Edit View SavedViews Run Tools Window Help 144140959 Jugen uiy PM QGOOOORHG D gt a gt e lt P r E Dee gt IB SE TA Mm va Ba y a E e P ud s 3 Soch gt g a Ka GE 15 EI e Units m3 s Coords 2082 4E 2351 5N 883 Z Figure 7 1 Orthogonal Display Lo gt 4 Ventsim Visual e eg File Edit View SavedViews Run Tools Window Help 5930 Stope He O42 Orepass POrepass ei usher OrePass sy Room ve Us Conveyor T4 Conveyor Units m3 s Coords 12363 0E 194324N 883Z Figure 7 2 Perspective Display Hint When performing true PLAN or SECTION views ensure that ORTHOGONAL mode is chosen to prevent perspective errors in th
264. irways to see optimisation recommendations Figure 26 3 Global Optimisation 26 2 Cost Data Function The program contains a number of data types which show ventilation costs per annum for airways These are located under the colour and text ENERGY category and include fan fix power costs friction losses per airway and friction losses per unit length Perhaps the most useful way to consider ventilation costs is not to look at the cost of running fans but rather look at the cost of pushing ventilation through individual airways located throughout a mine Of all the cost data function perhaps one of the most useful is the friction cost per unit length This describes the friction pressure loss along an airway length and is directly proportional to the ventilation cost per unit length of development For example if a particular airway reports a ventilation operating cost due to friction loss of 800 yr per metre then over a mine life of 10 years the total cost of pushing ventilation through the heading is 8000 per metre It is not hard to see that increasing the mined airway size slightly for say an additional mining cost of 500 per metre will quickly pay dividend in reduced ventilation costs By using the Ventsim Visual Display Manager and colouring data to the ventilation cost per annum per unit length high cost airways will be highlighted and can be quickly identified and analysed for potential different sizes In the Blue
265. is handy for excluding sections of a model design which have yet to be mined or perhaps removing old sealed of filled sections of a mine which no longer carry ventilation Excluding airways will speed up simulation for the remaining airways Prevents Ventsim Visual from changing the airway s airflow direction during simulation An error is displayed after simulation if an attempt to reverse is made This function is useful to ensure critical airflow locations underground are not arbitrarily changed without first warning the user Always shows text data for this airway when the LIMIT view option is set Specifies the gradient of the airway as a percentage For example a gradient of 10 results in an airway increasing 1m in height for every 10m in horizontal length If a group of selected airways needs to be change simultaneously use the TOOL gt APPLY GRADIENT option in the EDIT form menu Note that the first selected airway clicked with the EDIT button will be the airway from which the gradient is applied Specifies an evas or diffuser for the airway outlet This function will only be simulated on a surface connected airway and will only have an influence on an exhaust airway An evas or diffuser reduces exit velocity pressure losses to the mine lowering overall total system pressure requirements to produce the same airflow Where fans are present an improvement in the performance of the fan will be noted with increasing evas sizes N
266. isual User Manual Page 278 Figure 27 9 Use the Edit Info to view airway flow pressure and power E 246 Figure 27 10 Colouring showing contamination spread time in seconds 247 Figure 27 11 Initial imported DXF strings in Ventsim VISUAL EE 248 Figure 27 12 The Level Ele VA ION database A AAA AA A A 249 FOQUEC 2 7 19 SEE rway layer AMES AAA A A dida 249 Figure 27 14 Initial selection of all decline oirwgys EE 250 Figure 27 15 Select ANO eat tre IEC EH ee 250 FIGUIE 27 16 EReshiana EXNGUSE AIF TYPE TOO EE 251 Figure 27 17 Ire findl DXF import resul showing Te orir is 252 Figure 27 18 Resulting conversion with colour levels reSCt s ccsssccsssseessssessssessessssessssesessesesessuecsssssessessssesasessusessusessusesassseasesesseseasesensessesesateeeegs 253 Figure 27 19 Airways coloured by ANTOINE ANA 254 Figure 30 Customised TUCK IGE S raisni ie EAE E TEE TE T OER 264 Ventsim Visual User Manual Page 279
267. isual User Manual Page 84 7 4 4 7 4 5 Recirculation ADVANCED Financial Simulation ADVANCED Performs a recirculation search simulation which attempts to find any paths and portions of airflow that recirculate in the model Any recirculation paths are highlighted after simulation and the portion of each airflow recirculating through each airway will be shown on the screen as colour and text For further information see Recirculation Simulation under the Menu Bar Chapter Performs a financial and airflow simulation for multiple airway sizes to assist in determining the optimum airway size for mine ventilation flows For further information see Financial Simulation under the Menu Bar Chapter Ventsim Visual User Manual Page 85 8 1 1 Data Category 8 THE DATA TOOLBAR a G Attributes Levels sin T Airflow Quantity lk The DATA TOOLBAR control the colours and text displayed on the screen of Limits the data types shown in the adjacent pull down menu to the category type specified Pressure Attributes Energy Heat Identifiers Contaminants Rock Measured Figure 8 1 Select a data category followed by a data type Show data types such as air flow volume velocity mass flow and density Shows pressure related data such as relative to surface barometric and friction loss Shows airway resistances friction factors and shock loss numbers Shows power and cost calcula
268. it fans for mine ventilation e Assist in financial analysis of ventilation options e Simulate paths and concentrations of smoke dust or gas for planning or emergency situations Ventsim Visual Advanced provides additional tools to e Undertake full thermodynamic analysis of heat humidity and refrigeration in underground mines e Take into account air compressibility for deeper mines e Provide tools for analysing multiple different airways size options both financially and for establishing ventilation capacity e Show dynamic time based analysis of contaminant gas diesel fume or heat spreading through a mine from different activities e Provide a tool to check for recirculation in mines e Simulate Diesel Particulate Matter DPM concentrations through a mine Ventsim Visual Premium provides additional tools to e Dynamically and simultaneously simulate multiple ventilation parameters contaminant gas diesel fume heat and airflow including the simulation of fire heat and fumes Models can be programmed to self modify during simulation This tool is called VentFIRE e Connect and load external data from mine sensors for example to display realtime data within a Ventsim model This tool is called LiveView e Ventlog A separate software program to record and store measured ventilation data from underground areas Ventsim Visual can link to this data and show it within a 3D model This tool is called Ventlog
269. it weight of diesel fuel consumed Although the theoretical combustion reaction portion of water produced to fuel consumed is only around 1 1 the operation of a diesel machine in a mine environment results in a greater release of water into the air due to accelerated evaporation of water around the machine from a wet roadway or walls for example compounded by other sources such as handling of moist or wet material wet exhaust scrubbers and cooling systems used by the machine result in a much higher value A value of five 5 or more is generally recognised as giving a more realistic result for water introduced to the air by mobile machines Stationary machines may be closer to the theoretical value The default water to diesel ratio is used on all diesel sources in the model To use values other than default the sensible and latent heat will need to be entered separately instead of a single diesel heat source Diesel Particle Emissions Describes the default amount of diesel particles emitted from a diesel engine per unit of diesel engine power This value is applied to diesel heat sources placed in a model to assist in diesel particulate matter DPM simulation for the model The value is highly dependent on the type of diesel engines catalytic converters and scrubbers being used on the exhaust as well as the type of diesel fuel used In most cases tests will need to be done on engine exhausts or information gained from diesel engine manu
270. ive 5 points is recommended 4 Enter the curve points and fan information in the Fan Database edit form 5 To utilise the fan within the model ensure the Fan Total Pressure method is selected in the Settings and use the Edit Box to place a fan within an airway 14 2 Fan Pressure Types Where both Fan Static and Fan Total pressure curves have been entered for all fans in the database Ventsim will automatically use Fan Total Pressures for simulation calculations Unlike Ventsim 2 0 the simulation method is no longer selectable Ventsim will only use Fan Static Pressure for simulation if a fan does not contain a Fan Total Pressure curve 14 2 1 Simulation Handling Exit Velocity Pressures occur on any airway or fan discharging air to the surface atmosphere of Exit Velocity When considering fan pressure requirements the exit velocity pressure loss is added to the Pressure Losses mine resistance system pressure losses to calculate fan total pressure requirements Fans must therefore provide sufficient total pressure to overcome both the mine resistance and the surface velocity pressure losses If only Fan Static Pressure curves are used in a simulation the exit velocity pressure is ignored If some fans have only Fan Static Pressure and others have Fan Total Pressure curves then Ventsim will simulate using a Mixed Pressure method where exit velocity pressure are ignored for all airways EXCEPT for surface exits that contain fans
271. ive values indicate the relative pressure is lower than the surface pressure while positive values indicate the opposite Relative pressure in different parts of the mine can help show which direction air would flow if they joined Air will always flow from higher relative pressures to lower relative pressures if a path is available Note As the relative pressure describes airway pressure at an equivalent elevation if effectively ignores elevation and barometric effects of depths Describes the calculated barometric pressure at the start and end of an airway Barometric pressure increases with elevation depth and is in addition to any pressure influences on the model by fans or other pressure sources Barometric pressures and the resulting densities are an important factors in fan performance and heat simulation Describes the frictional pressure losses along an airway plus pressure additions due to fans or other pressure sources A negative value indicates frictional pressure drops are larger that pressure additions to an airway A positive value indicates pressure additions from fans or fixes have more than overcome frictional losses and contribute to system pressure increases elsewhere in the model Heat data shows various air conditions derived from heat simulation 88 EDIT 1 airways 100 0 m File Select Airways Tools Airway Fans Heat Contaminant Gas Sensors Info Notes ER Thermodynamics Temperatures 29 9 C 42 5 C
272. izontal The cost of mining a unit volume of rock for horizontal or inclined airways This figure is an approximation used in the global optimisation routines to calculate efficient airway sizes If a mine has an approximate cost per linear distance eg per metre for each tunnel size this can usually be approximated back to a fixed cost per metre and a variable cost per m3 which is largely consistent over different airway sizes Ventsim uses both the fixed and variable component in calculating total airway cost Cost Shaft The cost per unit volume for mining vertical or inclined ROUND shafts As with horizontal costs this can be approximated if the linear cost of vertical airway mining is converted to a fixed linear and variable unit volume cost Ventsim uses both the fixed and variable component in calculating total airway cost Ventsim assumes any airway with a slope greater than 45 degrees is defined as a vertical airway Cost Vertical Other The cost per unit volume for mining vertical raises that are NOT ROUND The cost basis for a raisebored airway round and a blasted vertical area eg a winze or Alimak raise are normally very different hence this category allows costs of different types of vertical development to be differentiated Ventsim assumes any airway with a slope greater than 45 degrees is defined as a vertical airway Fan Purchase Cost The purchase cost is an approximation of a fan total cost per unit of power For example a cost es
273. k Density 2 810 kg m3 l Diesel Engine 285 0 kw Moisture D misec Linear Source Rock Surface E Diesel Engine 0 0 beses 00 Win Sen Heat Latent 0 0 Wim Custom 0 15 Moisture 0 0 g sim Age Entry Exit 5 00 5 00 Linear Source Oxidisation 0 0 Wim VRT Temperature 447 447 Heat Sensible 0 0 Wim Diesel Engine 0 00 KWim Rock Temperature 36 5 50 8 aes Heat Latent 0 0 Wim Air Temp WB DB 31 7 51 0 gt Moisture 0 0 g s m Diesel Emission 0 120 g kW hr Advance Rate 0 0 wu 0 0 Wim ee O bis on cascal E E Gen Zi Ventsim Visual User Manual Page 103 9 6 1 Heat and Cooling Heat Assistant Calculator Preset On or Off check box 9 6 2 Point Sources Heat Sensible Heat Latent Refrigeration Moisture Diesel Engine 9 6 3 Linear Sources Oxidisation Sensible Latent Heat Figure 9 9 The Edit Box Heat Entry Tab Advanced Version Only Sets the heating cooling and moisture inputs for the airway ES The Heat Assistant helps calculate or estimate heat and moisture values to place within airways The heat assistant calculator is described further in the next Chapter The check box allows heat and cooling preset sources to be turned on or off while leaving the preset in the airway If the box is unchecked the preset will have no effect on the model thermodynamics Presets which are turned off will show in the model as a grey colour Note that custom heat values which are not presets cannot be turned on or off and
274. ke red blue clear or yellow possible smoke source Contaminant reports can be placed by selecting the location tool bar button under the contaminant button A RED pin can be placed to designate a contamination report Ventsim will assume that all airways downstream from this report will also be in smoke coloured red and all airways above the report will be a possible source of smoke marked in yellow The BLUE pin indicates clear air Ventsim will assume that all airways upstream from this point are in fresh air coloured blue Once reports are place select the location simulation function to simulate and colour the airways around the reports As more reports are received the YELLOW possible smoke source areas will decrease and the location of a fire or contaminant source can be narrowed EXAMPLE Mine Control receives a radio report that smoke has been smelled in a decline location Checks reveal that other personnel further up the decline cannot smell any smoke The vent officer places a REPORT SMOKE tag on the airway where smoke was reported and a REPORT FRESH tag on the clear airways Pressing LOCATION SIM will show the likely paths of the smoke in RED what areas are likely to be fresh in BLUE and what airways may be the source of the SMOKE in YELLOW After receiving two more reports of smoke in different areas and fresh air in other areas the simulation suggests the smoke could only be coming from a workshop area in t
275. ks at a ratio of around 1 3 Ventsim will alter the generation of CO2 and CO gases based on the equivalence ratio and the combustion yield factors used in the preset For an underground fire in a confined place at extreme temperatures even in the presence of a theoretically excess amount of oxygen a fire can produce significant amounts of incomplete or chemically reduced combustion products To force Ventsim to produce higher amounts of carbon monoxide the equivalence ratio can be moved towards fuel rich results by adding a shift factor If in doubt as to the behaviour of the fire it is suggested to use a shift factor of 1 or more to force the maximum amount of Carbon Monoxide to be produced Limit O2 Upper Lower Ventsim will modify the defined fuel burn rate based on the oxygen limits to produce a more realistic fuel burn profile For example most open flame sources will diminish significantly below 15 oxygen and continue diminishing as oxygen levels reduce further Between the upper and lower limit Ventsim will limit the fuel burn to proportionally less than the defined amount set in the airway reducing combustion rates linearly between the upper and lower limits Combustion of the fuel will cease below the lower oxygen limit To disable this behaviour set both limits to zero 0 Maximum moisture Controls the maximum flow of moisture to a rock surface available for evaporative cooling release rate in millimetres mm
276. l Lock On References Check Intercept Perspective View Es Locks on to the closest airway when adding moving or copying new airways Deselecting this option will allow airways and nodes to be finely moved without locking on to a nearby node or airway or to travel through each other without connecting Hint The lock target can be deselected when arranging airways which are closer together The lock function when selected will normally lock on to the closest available airway ensuring a positive join between the airway Warning If the lock target function is turned off airways may not join into each other precisely even if they appear close or overlap resulting in no exit or entry errors The lock target function should always be selected when you intend to join into other airways or nodes You can check whether airways truly join into each other by turn on the NODE display Allows transparent non active airways to be locked on to selected or edited Transparent airways are normally treated as invisible by the program and by default cannot be selected or changed Enabling this function will allow the airways to be selected or edited the same as any other airway Forces new airways or moved or copied airways to be drawn exactly vertically when the vertical movement function is chosen with the SHIFT key or the RIGHT MOUSE button while drawing When this function is not selected airways can be moved both vertically and para
277. l it can cause overpressure and heat buildup and is therefore no longer permitted Turn the fan OFF instead from the EDIT form of remove the fan If the fan is turned OFF click on SELF CLOSING if you want to ensure air does not leak back through the fan Similar to overpressure across resistance but the error code will target the airway with the fan or fix not the resistance Changing the fan or fix or alternatively removing the high resistance will correct the problem Ventsim Visual cannot resolve of pressure or airflow volume during simulation Ensure no unusually airways fan pressure or pathways exist within the model model No fan static pressure curve is available for the fan but a static curve has been selected in the Edit Box or the Settings Menu Enter a fan static pressure curve for the fan or change the Edit Box setting to a Fan Total Curve FTP or change the Global Fan Pressure method in the Settings menu to Total Pressure Method No fan total pressure curve FTP is available for the fan but a total curve has been selected in the Edit Box or the Settings Menu Enter a fan total pressure curve for the fan or Change the Edit Box setting to a Fan Static Curve FSP or Change the Global Fan Pressure method in the Settings menu to Static Pressure Method Ventsim Visual User Manual Page 274 32 2 1 Meshing error Ventsim Visual cannot create a workable mesh of airway loops meshes required for a
278. l available ranges Sets the stage number or name of the model Only airways on the currently selected stage will be shown The name of the stage can be changed by RIGHT CLICKING the combo box and selecting RENAME STAGE Stage 1 For more information on staging see the Staging Section 7 3 Editing Functions DI DA PONGS OD LS Places the program in view mode Draw a window to zoom into part of a model The front most airway in the view window will define the point of focus for the zoomed in area To zoom into area behind other airways ensure the zoom window does not contain any portion of the front airways Centre the view on the airway Centres the view on an airway so the screen can be rotated around the point clicked Edit the airway Left clicking the mouse on top of an airway will show the Edit Box for that alrway Press and hold to pan the screen horizontal around the current Edit Plane Ventsim Visual User Manual Page 77 Click to centre the Edit Plane and rotation point about a specific airway or point on the Edit Plane Right Mouse Click IN ALL MODES right mouse click will rotate the model graphics about the point of focus Hold and move the mouse vertically to tilt the model Hold and move the mouse horizontally to spin the model 7 3 2 Add Places the program into draw add mode to allow creation of new airways or measure between airways The function has several sub functions available by clicking the small
279. l blasts As a result there was potential to underestimate blast gas concentrations or underestimated clearance times Ventsim 3 0 dynamic explosive contaminant simulation utilises a more automated method and works on the theory that any blasting source will initially produce a mass of pure blasting gases based on a yield factor for the explosives that must be bled into the surrounding atmosphere Rather than trying to calculate an initial throwback volume the rate at which this pure gas is bled into the surrounding atmosphere is based on an adjustable logarithmic decay series which in the experience of Chasm Consulting appears more consistent with practical measurements of actual blast gas releases underground When explosve gas enters a mine airway the ventilation system must then remove the contaminated air from the region through the rest of the mine to the exhaust The rate at which the fresh air ventilation can initially remove the contaminant depends on the efficiency of the ventilation flow to access and remove all fumes from the blast zone labeled the dispersion factor in Ventsim For example in an open free flowing drive with good airflow contaminant would be expected to be removed quickly as the fresh air forces all pockets of fumes and gas quickly down the drive A blind heading ventilated by duct which may be damaged or some way away from the heading end will clear slowly as the fresh air cannot efficiently re
280. l increase turbulence in an airflow and hence develop energy losses that can be equated to an increase in airway resistance Ventsim Visual uses shock loss as an extra length added on to the original drive length i e the higher the shock loss the greater the equivalent length which in turn increases the overall airway resistance Thermal diffusivity is the ratio of thermal conductivity to volumetric heat capacity Substances with high thermal diffusivity rapidly adjust their temperature to that of their surroundings because they conduct heat quickly in comparison to their volumetric heat Capacity or thermal bulk Thermal conductivity k is the property of a material that indicates its ability to conduct heat It appears primarily in Fourier s Law for heat conduction The ratio of area of wet airway surface to dry airway surface A fully wet surface is defined as 1 0 while a fully dry surface is defined as 0 0 Relative humidity describes the amount of water vapour that exists in a gaseous mixture of air and water It is defined as the ratio of the partial pressure of water vapour in the mixture to the saturated vapour pressure of water at a prescribed temperature Relative humidity is normally expressed as a percentage The density of a material is defined as its mass per unit volume The density of air influence many psychrometric properties Te density of rock influences heat transfer and thermal Capacity behaviour
281. lation section 17 5 Reverse Contaminant Determines the source of air at a specific location A sourcing simulation is similar to a reversed contamination simulation It tracks airflow back from a placed contaminant source and indicates the percentage of airflow which contributes to the airflow through the contaminant marker This function is useful in determining where a location sources its fresh air from or for analysing ways to reduce or increase airflow sources from certain areas such as increasing airflow sourced from a bulk air cooler or decreasing airflow sourced from a hot production area Ventsim Visual User Manual Page 175 EXAMPLE Entering 100 as a concentration value and performing an air sourcing simulation will show which airways upstream are carrying the relative amounts into the original airway Back tracking the concentrations to the surface will show which surface airways are providing the airflow and may show values such as for example 25 decline adit 60 main vent shaft 15 hoisting shaft 17 6 Find Source Assists in finding the location of a contaminant source This simulation function was designed to assist in quickly identifying the possible locations of a fire or contaminant source e g dust or production fumes underground As people report the status of air from different locations for example smoky air or clear air the simulation will colour airways upstream and downstream as either smo
282. le fuel burning rate Heat from combustion also defined in the fuel source properties is added to the cell If oxygen is reduced below a predetermined concentration the fire is throttled if excess fuel is available and heat and gas output is limited Other gases are added to cells based on the yield y rates specified in the combustible fuel properties For critical gases such as carbon monoxide an upper and lower limit can be specified to simulate the carbon monoxide emission effects of an oxygen or fuel rich fire however this can be overridden to produce maximum carbon monoxide if a cautionary worst case scenario is desired Airflow simulation is done periodically period set by the user to recalculate the flow amounts and flow direction in the model The airway natural ventilation pressures are modified each time by collecting the aggregate air density of the cells within the airways In some cases this may change the direction of flow of air within the model Information is entered into a VentFIRE simulation using Events an event describes a change in input parameters such as a fire size or a change in diesel machines moving around fans stopping or starting or resistances such as a door opening or closing An unlimited number of events can be entered into a simulation at different locations and times An airway with multiple events can be sequenced to show changing conditions over time For example a fire may initially
283. le limits Ventsim Visual Advanced uses a modified method which takes into account density changes and mass flow balances A point defining where two or more airway ends share the same position Airflow at this point can split or join depending on airflow direction Estimation of how much load or weight an airway pressure loss would develop across a resistance It is often used for determining load on a vent door or bulkhead and is calculated by the pressure loss times by the drive or resistance area An interconnect series of airways that together form the model of an airflow design Ventsim Visual User Manual Page 256 28 1 14 28 1 15 28 1 16 28 1 17 28 1 18 28 1 19 28 1 20 28 1 21 28 1 22 28 1 23 Node Pan Pressure loss Resistance Shock loss Thermal Diffusivity Thermal Conductivity Wetness Fraction Relative Humidity Density A point defining the end or junction of an airway s The action of sliding the model graphics to a new screen position by using the right mouse button The loss of air pressure along a length of airway due to friction loss fans fixed pressures or fixed quantities etc A value describing the difficulty air will have moving down an airway It is derived from a combination of airway size friction factor length shock losses and air density A factor that estimates the effect a change in drive direction or size has on airflow Any such change wil
284. limits of decimal accuracy to convert from metric to imperial and back again If the decimal accuracy is too low some accuracy may be lost in the conversion process and the value input as an Imperial number may be returned slightly differently Use Mass Flow Replaces fixed flow input in airway edit forms with a fixed mass flow option Some countries utilise mass flows to specify air quantities in mine ventilation Ventsim Visual User Manual Page 146 13 1 1 Airflow 1 13 1 2 Airflow 2 13 HEAT ASSISTANT The heat assistant helps in calculating thermodynamic inputs into the ventilation model The calculator can quickly establish required cooling heating or moisture loads which can then be accepted in the model The assistant is also useful for pre conditioning airflow to a required temperature and humidity to more closely simulate observed conditions underground Pressing Accept after any calculation will insert the values into the model airway for future simulation This will overwrite any existing heat values within the airway Warning The assistant calculates estimates only In some cases the assistant utilises an iterative technique with initial values sourced from the airway currently being edited The initial values can be changed as desired Because the simulation process utilises a more detailed multiple pass approach taking into consideration surrounding airways and rock heat transfer into the airway the re
285. lishing an economic airway size if it does not deliver the required airflow Airway shapes Round or Square A set of 10 airway parameters is stored for each shape type More complex shapes or fixed areas are not supported at this time Life The life in years required for the airway to be in operation This directly affects the ventilation operating costs of the airway and the effect of time value of money Discount The time value discount of money per annum The value of money will diminish over the life of project meaning costs saved up front in most case mining and fan purchase costs are worth more than costs saved in the future in most cases ventilation costs Other similar names associated with factor include the discount rate project hurdle rate rate of return or NPV net present value discount rate To use a value of money not diminished by time or to estimate undiscounted future savings use a zero 0 rate To evaluate projects however most mining companies will use factors ranging from 5 to 15 depending on the cost of money and the competing project values to be gained elsewhere with that money Fan Cost The capital purchase cost of fans required to provide ventilation power for the mine simulation Note that this uses an approximation of unit power cost approach which is only an estimate of actual fan costs and may vary substantially when compared to real fans of different sizes Nonetheless it provides an importa
286. ll internally automatically adjust resistances during simulation according to the local air density This behaviour can be overridden from the global settings or with the resistance Check Box on the edit form e If this box s not checked the resistance entered is assumed to be derived from a standard air density as specified in the Settings Menu for Simulation Air which is normally 1 2kg m3 unless set otherwise In most cases resistances are likely to have been derived from preset values and standard air densities and this option should remain unchecked e If the box schecked Ventsim Visual will assume an adjustment has already been included and will not attempt to adjust the resistance from density changes further Examples of this may be if the resistance has been measured at a specific site underground at a density similar to that simulated by the program Friction F Sets the friction factor for the airway Friction factors describe the unevenness of wall profiles which produces airflow turbulence and hence pressure loss The value can either be entered directly in the Friction F text box or can be selected from the pull down menu As with resistance new preset values can be entered by clicking the Friction button and entering new preset values in the Preset Spreadsheet The new Preset Friction Factors will be available for all airways Friction F Density Similar to the resistance density adjustment friction factors are also
287. llel to the plane of the viewing screen while being drawn Hint Airway drawn or moved with the Lock Vertical function activated can still be angled Simply release the SHIFT key or RIGHT mouse button while drawing and moving when you are at the desired elevation and the airway end can continue to be moved horizontally at the new elevation Locks the mouse cursor onto a referenced graphic surface or wireframe Ventsim Visual will preferentially search for airways when moving the mouse cursor to new locations If no airway is found if this option is enabled the program will search for a reference graphic imported graphics to lock on to Hint This function is very useful for tracing or moving airways on to imported referenced graphic locations By using the referenced graphics as a guide airways can be accurately placed within a model To force the program to use the referenced graphics only and not lock on to other airways turn the Lock Target options OFF Checks whether new airways intercept existing airways and inserts a node if they do The function works by searching surrounding airways for intersections or crossing paths that are close Turn this function OFF if you require an airway to cross another without joining for example an overcast airway or airways are required to be drawn very close together without being joined Hint When drawing Vent Duct within or close to an airway ensure this function is turned OFF The Vent Duct a
288. low enough regardless of the original user specified fuel burn rate of the fire The second option is designed to simulate the buildup of gases particularly in areas of low ventilation flow For example if fans are slowed or stopped during a coal mine emergency then the release rate of methane could be specified and the dynamic simulation would show how long it would take for gas to build to explosive levels Note this option mimics gas buildup by a volumetric replacement method where a portion of the atmosphere is periodically replaced by the emission gas This is suitable for relatively slow emission rates however for very high emission rates which may create a significant flow and push gases into areas without emissions a gas injection method using fixed flows of defined gases is recommended instead Up to three burning fuel types can be added to the event and the estimated rate of burn for the total fuel amount can be specified at the start and end of the time period for the event The different fuels can be proportionally varied by a percentage of the total amount specified The rate of fuel burn and heat output may be limited to less than specified if there is insufficient oxygen passing over the fire source The fire behaviour at low oxygen level can be defined in the VentFIRE settings page in the main Simulation Settings form For example if a truck fire is to be simulated then the total mass of combustible material on th
289. low of cold air Because airflow simulation in VentFIRE is based on a mass balanced Hardy Cross algorithm even though this takes into account the greater pressure losses and choking effects of airways produced from higher volume flows of hot air it does not take into account the short term periods were greater masses of cold air are being pushed out The net effect is that VentFIRE may temporarily underestimate the choking effect of the fire Ventsim Visual User Manual Page 219 24 LIVEVIEW Premium LiveView is an extension of Ventsim Visual software and will operate in conjunction with the main Ventsim Visual license LiveView provides a number of additional functions to enable the software to connect externally to data sources and display the data within the Ventsim model Examples of this may include airflows temperatures gases or pressures or even machinery such as diesel or electrical equipment LiveView also provides an interface to simulate ventilation models using captured sensor data offering an ability to display downstream simulated results from actual data 24 1 OVERVIEW OF LIVEVIEW LiveView can connect to multiple different data sources and extract data from those sources to display and optionally use the data in the 3D Ventsim model Because of the large number of different types of sensors and communications systems Ventsim LiveView does not attempt to connect directly with senso
290. lows are enabled the factor will be adjusted to the simulated local air density otherwise the factor is adjusted to the standard environment density setting If this setting is not enabled or the airway EDIT form has set the value to Already Adjusted then the actual value entered in the preset will not be adjusted Enables the simulation to adjust the preset resistance values to the local airway density Preset resistance values do not use friction factors therefore any friction factor setting is ignored When set to YES all preset resistances are assumed to be specified at a standard sea level density 1 2kg m3 and will be adjusted to suit the local airway conditions If compressible airflows are enabled the preset value will be adjusted to the simulated local air density otherwise the value is adjusted to the standard environment density setting If this setting is not enabled or the airway EDIT form has set the value to Already Adjusted then the actual value entered in the preset will be used HINT Density adjusted friction and resistance values are a potential source of confusion Most text books will quote friction and resistance values standardized to a 1 2kg m3 air density If standard values are used ENSURE that both of the Density Adjust options are set to YES If resistance or friction values are measured locally however then the values obtained are only valid for the density at which they are measured To use
291. ltering using the various selected tools Alternatively each tool can be selected and run individually from the other tabs Ventsim Visual User Manual Page 60 ad Filter All Airways Al Tools Simpify Binding Duplicates Convert to 3D Filtering Tools Y Run Simplification Y Run Binding Y Run Duplicate Search d Figure 5 14 Filtering Tools Combined Simplify allows the user to reduce the number of airways in a model to a more efficient number without affecting the overall model analysis It is particularly useful where a model has been imported via a DXF file and contains a large number of very detailed but unnecessary small connected airways Simplify will search a model for sequences of airways that may be reduced to single straight airways In doing so much of the overhead and effort required to set parameters to every airway can be reduced Note that the simplify function will only combine airways that have a single entry and exit Airways at junctions and split branches will remain untouched ee e a hieng Took D Lola e Simplify Parameters 0 ES Joined Angle Maximum 0 U Joined Length Maximum Simplify Options Use combined lengths Y Ensure no resistance presets filtered Y Ensure airway dimsensions are the same el Ensure wall types are the same 1 i 1 il 1 H d d d d d 1 i Simpli i 1 i n ij eme em em eem e rr rr rr
292. ly balance into the remaining void The will retain the preset gas mixture of the defined gas value but allow other undefined gases to changing depending on the airway gas content as simulation time Ventsim Visual User Manual Page 121 12 SETTINGS Ventsim Visual Settings Graphics Simulation System Settings General Settings provide control over a large number of parameters used in Ventsim for simulation graphical display and file handling Settings are normally saved specifically for the file in which they are modified for but can be shared with other files using the INHERIT function or the MASTER LINK function 12 1 Costing Defines the mining and ventilation cost components of a model These figures are used in calculating optimum airway sizes and total ventilation cost to run a modelled ventilation system ZS Wentsim Visual Settings Currency 5 E bining Cost Horizontal Fixed 800 m Cost Horizontal variable 130 m3 Cost Shatt Fixed 1600 m Cost Shaft Variable 180 m3 Cost Vertical Other Fixed 1600 m Cost Vertical Other Variable 180 m3 B Power Fan Purchase Cost S kW 1 000 Mine Lite 5 MP Rate 10 Power Cost Sikwh 0 10 Power Poywer Ventsim Visual User Manual Page 122 Currency The symbol used for the local region currency value This symbol will be applied in text displays and reports Ensure all costs defined in this section are set in the local region current value Cost Hor
293. m Visual will sort through a model identifying unnecessary detail which can be removed without adversely affecting simulation AI Tools Smplfy Binding Dupicates Corvetto 30 c AAA Filtering Tools Filtering Tools Y Run Binding Z Run Binding 4 Run Simplification 7 Run Simplification 4 Run Duplicate Search V Run Duplicate Search Start Ventsim Visual User Manual Page 163 15 4 1 Fans 15 4 2 Fixed Airflow Figure 15 5 Example show the effect of the Simplify Function to reduce airway data Alternatively airways can be manually simplified by using the toolbar delete function to remove node junctions between airways DUPLICATES find and or remove any duplicated or overlapping airways 15 4 Creating Pressure for Flow To produce pressure within a model to motivate airflow the following three methods can be used e Fans Utilise and fan curve to establish accurate working flows and pressures in a ventilation model e Fixed Pressures Use a consistent pressure to induce an airflow in a ventilation model Airflow will vary based on resistance encountered by the pressure e Fixed Airflows Use a consistent airflow to induced flow through a model Pressure required will be adjusted to whatever is required to produce the airflow Without at least one of the above methods to produce model pressures airflow will simply remain stagnant In Ventsim Visual Advanced a fourth meth
294. m by pressing the appropriate preset button When activated from the EDIT form the currently used preset will be highlighted in the Preset form oo EDIT 1 airways 78 7 r File Select Airways Tools Unique 0 17303 1 462 6 A T irwa e 17752 13980 Y YP E Surface Airway size estimator Close End C Square 7 Group Exclude Custom Width Fix Direction Show Data Preset activation buttons Evaz 5 Orifice Height Area Obstruction Length F Quantity Friction P Velocity gt Preset activation buttons 10120 CH Auto Shock kx D Nil Up to 100 different resistance presets can be entered Resistance presets can be applied to airways from the EDIT form Any resistance entered in the preset will be applied to an airway during simulation It is important to note that underlying airway resistances due to wall friction WILL ALSO be applied in addition to the preset resistance For example if a preset resistance of 10 for a DOOR is applied and the airway has an underlying resistance of 0 015 then a total resistance of 10 015 will be applied during simulation Ventsim Visual User Manual Page 119 11 2 2 11 2 3 11 2 4 11 2 5 11 2 6 11 2 7 11 2 8 Friction Shock Heat Layer Prim Layer Sec Air Type Fans Airways Profiles The reversing resistance is an optional field which applies a different resistance should an airflow be reversed durin
295. mber Find an airway with the specified index or unique number Fans Find airways with operating fans fans that are turned off or fans that are performing outside of their rated fan curves Fixed Find airways with fixed flows or pressures Heat sources Find airways with artificially heat cooling diesel or moisture sources Contaminants Find airways with contaminant sources set Errors Find model errors defined during the previous simulation 7 2 8 Lock amp gt The lock function controls how the Ventsim cursor attaches to other airways or graphics objects When editing this is often desirable to ensure airways attach correctly to other airways or reference graphics while drawing or editing however it may become problematic particularly in graphically crowded environments Transparencies References Vertical Intersections Individual graphical locks can be turned off using the function below Note that ALL LOCKS CAN BE TURNED OFF temporarily by pressing the CTRL key while editing moving or drawing airways Hint You may wish to carefully move airway ends or joins however the move keeps connecting the ends to other nearby or far away airways in the same view direction To disable this behaviour and allow fine control over moves simply hold the CTRL key down while moving to prevent the airways locking on to other objects Lock Target Ventsim Visual User Manual Page 74 7 2 9 Lock Transparency Lock Vertica
296. me Ventsim LiveView allows multiple different data sources to be used simultaneously For example two 2 different SQL databases and a Text file could all be used together to import and show data in a Ventsim model Ventsim Visual User Manual Page 220 24 1 1 24 2 1 How Does Ventsim LiveView use the data Step 1 Connect to a Data source e The data representing all the available different sensor values is imported into Ventsim e The user selects what sensor data records are to be made available for display and use in the Ventsim model e lfthe imported data does not contain information describing the type of data for example airflow velocity gas temperature etc then this information must be set for each individual sensor data item The selected data records and sensor information are stored in the Ventsim model for future reference so this does not need to be done again e If the data source does not contain the airway location then the airways must be individually edited and the sensors assigned to the correct airways e Finally the data can be displayed and if required simulated in the Ventsim model Y Ventsim Visual 3 ConnectorTest vsm File Edit View Savedviews Run Connect Tools Setting P i el 9 G BE amp ANO vs SS Fevourte o Leves m S T cas gt 24 2 Creating LiveView Data Connections A LiveView data source connection is a database or a file which contains external sensor
297. measured values in Ventsim you will need to consider one of the following options OPTION 1 If all preset values are measured at the true mine density and will not be used or duplicated elsewhere in the mine then simply set the density adjust setting for resistance and or friction values to NO OPTION 2 If only some values are measured and other values are standardized to 1 2kg m3 then you will need to use the EDIT form setting to set individual airways to Already Adjusted the check box next to the resistance or friction value OPTION 3 To avoid the potential confusion of Option 2 you may want to simply convert all of your measured values at the local mine density to a 1 2kg m3 standard and set both settings to YES This also has the benefit of allowing the setting to be used elsewhere in the mine at different densities Defines the default reverse fan performance relative to the original fan curve for the pressure and quantity of a fan running in reverse These factors decrease the performance of fans set to run in reverse for emergencies for example in the EDIT box Note that the default values may be overridden by values directly placed in the Fan Database for individual fans TRUE Ventsim Visual will ignore all warnings related to No Entry or No Exit errors found during simulation airways with no other airways joining FALSE Ventsim Visual will only ignore airways which have been set to 4 ow Closed
298. ment and mine infrastructure While referenced graphics do not interact directly with ventilation circuits they provide a useful visual and construction aid to developing and presenting models Mine ventilation model airways and sizes can be directly compared to actual or design development surface terrains can be used to ensure shafts are set to the correct elevation while orebodies and stope wireframes can be used to ensure ventilation circuits are not developed in the wrong area and have adequate ventilation designs to control airflow Ventsim Visual User Manual Page 22 3 9 Experiment Finally by all means experiment with the program Load up and view some of the included demos Most features have a Tool Tip attached to them which will provide further information if the mouse cursor is hovered near them Ensure you save your model files frequently and create backups where necessary Craig Stewart Author Ventsim Visual 2013 Ventsim Software Ventsim Visual User Manual Page 23 4 THE VIEW WINDOW Ventsim Visual operates in a full three dimensional 3D graphical environment The main Ventsim Visual window contains all the functions you will require to create edit view and simulate airway models Note that some of these functions may differ between Premium Advanced Standard versions Ka Ventsim Visual Il Beta _ blue_sky vsm Example Metal Mine with Problem ew Savedviews Run Connect Tools Se
299. mported Coordinate Centre Defines the centre of the grid system from which the grid lines will be drawn Note that this can only be specified if Automatic Grid Centering is turned OFF otherwise the centre numbers will be automatically adjusted when the model is viewed or reloaded Level Range Ventsim Visual User Manual Page 128 The range of elevations to show around a single selected level Selected levels may be chosen from the RIGHT CLICK mouse popup menu and limit the range of airways data shown on screen Orientation of Elevation X This option should only be used for CUSTOM grid orientation Grid NORTH orientations do Axis Y Axis not require these settings to be adjusted Spacing for Grid The spacing between grid lines on the screen 12 3 5 Icons 3 Wentsim Visual Settings HE E El Graphics Background Colours Controle Coordinates El Icons Custom Resistance Display Threshhol 0 00000 Ns2ime Transparent Icons EI Rendering Anti Aliasing Black face culling Hide text while rotating Maximum graphics frame rate active Maximum graphics frame rate inactive Perspective Rotation Damping Amount Rotation Inertia Show Thick Lines Transparency Dimming View Type 3D Ves Ho Yes No 120 25 No 40 Yes No 0 4 Perspective Airway Scale 1 Size Airway Text 12 Size Arrows 10 Size Data Text 10 size Grid Section Text 8 Size Icons 5 Size Mode Text 12 Size Modes 10 Figure 12 1 Graphics Setting
300. much water is attempted to be applied the excess will appear as condensate in the simulation Another application for adding moisture is evaporative cooling however these are not commonly used in mines unless very dry warm air is present To simulate evaporative cooling ideally a water balance should be undertaken to identify water being added to the air from an actual installation Alternatively a temperature difference before and after the evaporative cooling chamber will allow Ventsim Visual to estimate the water balance in the Edit Box_Heat Assistant Water may be picked up via evaporation via any wet material or ponded water Once again the problem of directly applying a water flow volume to the air is that evaporation will change depending on the volume flow and velocity of the air A better alternative to applying water over wet or flooded areas is to increase the wetness fraction of the airways 20 4 Application of Refrigeration The application of refrigeration for deeper or hot underground mines has become a routine requirement for many mines as they push deeper and environmental considerations become more pressing There are several different types of refrigeration processes used in mines Refrigeration uses a heat exchange process where an amount of input energy normally electrical or Ventsim Visual User Manual Page 192 20 4 1 Placement of Refrigeration Sources sometimes diesel is used to create a heat exchan
301. mulation the graphics view can be changed to show different location and colours and text can be changed to show different types of data At any time the simulation can be paused to allow the user to examine areas of interest or to check the results currently stored in the Monitors Multi Sim VentFIRE also has an option called Multi Sim where the user can select a number of different Simulation types of simultaneous simulations from the Multi Sim options Unlike the Fire Sim option Multi Sim allows a defined series of simulation to be selected For example a dynamic heat and DPM simulation may be required to analyse heat and diesel fume build up in parts of a mine during mining activities In this case the Multi Sim Options of HEAT and DPM would be selected and the Multi Sim simulation option selected to perform the simulation Explosive This is an experimental function to inject large pressures into a mining region defined in Simulation the airway gt contaminant edit tab to analyse pressures on regulators caused by a gas or dust explosion It is not currently supported by Chasm Consulting Program A number of rules MUST be observed during dynamic simulation limitations during simulation e Airways must not be deleted or added during simulation e The normal steady state simulation buttons must not be used e Events cannot be changed added to or removed during simulation e Airways CAN be modified with changed resistances or fans
302. must be removed if no thermodynamic effect is desired Point Sources of heat and moisture are applied to one specific location within an airway The thermodynamic change occurs immediately at that point Adds ve or removes ve sensible heat from the airflow The number will be coloured RED ve or BLUE ve according to the heating or cooling effect of the value Sensible heat is added or removed without changing moisture content If sensible heat is removed and the air temperature dips below the dew point moisture will condense and will be removed from the air by the simulation Adds ve or removes ve latent heat from the airflow Latent heat is sometimes describe as a moisture heat and does not directly change the air temperature but rather increases ve or reduces ve water vapour in the air Sigma Heat and Enthalpy increases with latent heat addition Removes sensible heat from the airflow If heat is removed and the air temperature dips below the dew point moisture will condense and be removed from the air by the simulation Refrigeration is essentially the same as placing a negative Sensible Heat and is included as a separate item to clarify its intended function within the model analysis Adds or removes moisture in an airflow Moisture addition has a neutral effect on airway heat content and is therefore added without changing the Sigma Heat content of the airway The effect of adding moisture is therefore an
303. n screen The select multiple airways for editing in VE 142 Waming no entry connection Ventsim click on the items hold CTRL to select A Waring no OY CAMEO i Airway 385 Waming no exit connection multiple items and click SELECT Airway 378 Waming no exit connection 32 1 Warnings e Warnings can generally be ignored as the simulation will complete despite the warnings They may Simulate Sa however be a sign of a more serious problem and should still be investigated 32 1 1 no entry airway or There is no airway entering the airway therefore no airflow can occur The airway is not surface connected to the surface or marked as a closed end The program can be set to ignore connection these warnings in the Settings Airflow Simulation menu Resolution Simply connect an airway to the entry connect the airway to the surface or marked as a closed end in the Edit Box 32 1 2 no exit airway or As with no entry warning surface connection 32 1 3 no entry or exit As with no entry warning description 32 1 4 airway stopping An airway stopping has been placed in series with another airway stopping Only one redundant stopping is required Resolution None required although a stopping can be removed if desired 32 1 5 fan interfering A fan has been placed directly in series with another fan The pressure imbalance between with another fan the fan curves may cause difficulty in resolve the model
304. n airways are large or very close together Displays or hides the main grid Note that in a section vertical view the grid automatically changes to show elevations Displays or hides nodes junctions of airways This option can also show or hide individual types of icons by clicking the sub option drop down arrow to the right of the button Displays or hides icons on airways Display or hides arrows showing airflows Displays or hides reference graphics for example DXF graphics or data imported into Ventsim Provides options for limiting the amount of data displayed in a model For complex models displaying data for every single airway segment this can lead to a cluttered display and is often unnecessary particularly if the data shown is largely the same for example airflows For other items however such a heat flows this large amount of text data can still be useful Fie dt Vew Seba Fun Tack ee 10D das A vi e aros gt Queries A 4 142 9 14288 o T 191 7 91 6 91 6 86 6 Ventsim Visual User Manual Page 70 Figure 6 1 Example of limiting text display Hint For data which may vary from one end of an airway to another such as temperature Ventsim Visual will always show the ENTRY data on the airway unless otherwise specified 1 Show Limited Only displays text nodes and or arrows on airways which specifically have Show Data option set in the EDIT box For example a loop in
305. n either the Sensor Editor form or the Airway Edit form to specify whether to sensor will help simulate the model data or whether it should be only passively displayed 24 5 DISPLAYING THE SENSOR DATA Once the sensor information is imported and the sensors assign to airways the data can be displayed by clicking the Connect gt LiveView gt Update Once or Update Continuous menu Clicking Update Continuous will continually update the model with sensor data at intervals defined in the LiveView Settings page If the automatic simulation option is chosen the downstream result of the sensor will be displayed on other airways For example if the sensor is an AIR VELOCITY sensor then the airflow in the sensor airway will be restricted to the sensor velocity and all airway leading to an from this airway will be adjusted accordingly WARNING Using Sensors to simulate model airflows may not necessarily correctly predict ventilation conditions in other airways For example if a change in airflow is transmitted by the sensor then this may be because a fan has been turned off or a door has been opened or closed If these other ventilation items are not also input into Ventsim although Ventsim LiveView can accept regulator and fan operational sensor data as well then the simulated airflow activity may not be correct Airways with sensors will display a sensor icon and a show a box describing the sensor data Ventsim Visual User Manu
306. n or preference of the mine The imperial column in the table may even contain metric units if required by setting the imperial unit name to a metric text value and a conversion factor to convert between metric types eg 1000 could be used to convert metres to millimetres al Conversion Units File Edit W Unit Name sted Metric Unit Decimals Imperial Unit Decimals Multiplier Addition E Area Volume Pressure ft tz Hi min wg 3 2808 10 7639 35 315 4 015 0 2953 12237 0 06243 196 848 2 1189 2 20462 2 20462 0 2248 7 0 43 3412 2 56 87 kPa Pam kg m3 m s m s kg s kg N CO ppm kJ kg k s kW Pressure Atmos in Hg Pressure unit Length Air Density Velocity Quantity Mass How ml aw ot lb Tt3 ft min kt3 min lbs lbs lbf CO ppm Btu lb Dud Btu min Mass Thrust Contaminant Heat Content Energy Flow HeatOutput sch Ss l E 1 E ela A SA RIA dd dd od A E E E A E E E E E m E E E F Figure 5 19 Conversion Table Sets the number of decimal units to display on the screen and in text displays Ventsim Visual User Manual Page 67 Example A decimal value of three 3 for example will display a value of 123 123 on the graphics display or in the spreadsheet view Caution While the metric unit text name can be changed the underlying metric value cannot be changed Forthis reason the units must remain the same as preset in Ventsim For example
307. n overall heat gain The exception may be in highly reactive ores or where there is very low airflow While there are formulas to estimate the reactive heat of certain types of ores it is generally unreasonable to try to calculate this value theoretically due to the variability of oxidising ores In most cases oxidisation heat can be estimated from empirical measurements from actual underground areas All electrical fans generate heat which is dissipated into the surround airflow The heat generated is equivalent to the input electrical power and is dissipated into the airflow through a combination of electrical motor inefficiencies blade inefficiencies and friction losses Ventsim Visual automatically includes heat from fans and fixed flow in a model heat simulation therefore there is no need to include fans as a separate heat source Ventsim Visual User Manual Page 191 20 3 1 20 3 2 20 3 3 Dust Suppression Evaporative Cooling Wet Material Dam Flooded airways 20 3 Injection of Moisture While Ventsim Visual automatically considers moisture derived from wet or damp strata surfaces direct user moisture injection to air from underground sources is unlikely to be commonly used in most models It is important to note that moisture application to air does not directly alter the heat content of the airflow providing the moisture added is the same temperature as the airflow Instead through the process of evapo
308. n will be taken when the duplicate airways are found Moves the model airways on to a 3D surface or contour plan effectively converting the model from a 2D plan to a 3D model Note that if only parts of a model need to be converted they should first be selected with the Select tool a Filter All Airways Convert Airways to 3D Options V Use reference 3D lines Z Use reference 3D Solids Action Simple method fast Detailed Method slow Convert to 3D Figure 5 18 Filter Airways Use Reference 3D Lines Uses lines such as contours loaded in from a DXF as a reference to convert the model to 3D Use Reference 3D Solids Uses solids such a terrain polygons loaded in as a referenced DXF object to convert the airways to 3D Simple Method A fast method which searches the closest 3D reference point Suitable for relatively flat conversions Detailed Method A slower method which searches for the closest vertical intersection It is more suitable for rugged 3D surface conversion HINT To convert a multi seam or level model to 3D using this function individually group select the airways required and ensure only the relevant 3D DXF object for that level is turned on before conversion The utilities sub menu provides many functions to assist with manipulation of airway data particular raw data which may have been input from a DXF import or similar Ventsim Visual User Manual Page 64 Swap
309. nce in psychrometric properties of the mixed versus the whole chilled airflows will actually diminish The dryer warmer air resulting from the mixed case will actually enhance evaporative cooling from damp or wet airways resulting in potentially cooler moister air while the case with the cooler moister flow will enhance geothermal heat transfer from rock surfaces and reduce evaporative cooling The resulting air temperatures some distance from the refrigeration source may be very similar The type of refrigeration plant will have subtle differences on the effect on air temperatures and humidity A closed plate cooling tower versus a spray chamber for example may result in a different relative humidity due to the air to moisture contact mechanism particularly if the dew point temperature of the air is not reached or the air is very dry Additionally the presence and location of electrical pumps and equipment required to run the installation may introduce heat back into the airflow for an underground installation but not a surface installation As Ventsim Visual only considers the refrigeration output of a plant the plant performance in achieving this output is largely irrelevant to the simulation although plants will perform differently depending on ambient temperatures to be cooled The plant design to achieve this refrigerative output for the ambient working temperatures is an extra design criteria outside of the scope of Ventsim simulation
310. ne heat output The efficiency of a diesel engine can be specified in the Heat Simulation settings Diesel combustion results in the production of heated exhaust gases and water vapour which is transferred to the surrounding air In addition additional water vapour source from engine cooling systems or the surround environment is added to the air in the form of evaporation This ratio of diesel fuel to water is set in the Settings Menu and is assumed the same for all diesel heat sources If separate ratios need to be considered the sensible and latent heat will need to be entered instead of a single diesel heat figure Perhaps the biggest source of confusion in applying underground heat is the application of latent heat In general latent heat which is essentially adding heat to the air in the form of water vapour should rarely need to be considered as a separate user input While latent heat is internally calculated by Ventsim Visual in the application of strata evaporation and diesel equipment it rarely needs to be applied directly by the user The only exception may be to condition air to a required wet bulb and dry bulb temperature or in the application of heating to a mine with propane or some other moisture producing fuel source Oxidisation heat is included for completeness but will rarely be required to be entered into a mine model For most mines with reasonable ventilation flows oxidisation will be generally insignificant i
311. neously This can greatly speed up creating a model 7 3 4 Select Selects a group of airways Selected airways are considered as a group by a number of other Ventsim Visual functions including Zou Delete Move Copy and Filter These options will apply changes to all selected airways simultaneously Left Mouse Click Selects or de selects the airway under the current mouse cursor Left Mouse Drag Fences a number of airways for multiple selection lt Escape gt De selects all currently selected airways Ehx gt HOS Joined Segments lt SHIFT gt Deselects fenced airways lt CTRL gt Individually selects or deselects airways ignoring the group Single Loose es setting or other group selection options Primary Layer 7 3 5 Multi Select Same Secondary Layer Options a SS Permits groups of airway to be automatically selected based Same Size on either an initial airway selection or subsequent selections Same Resistance Type with the mouse The selection mode will remain set until it Same Friction Fact Same Friction Factor is reverted back to the single airway select option or the lt escape gt key is pressed twice Same Shock Factor Same Fan For example to select all airways of the same size either i select a single initial airway with the select button and then same Air Type select the mult select option Same Size OR select the Same Heat Type Same Size option first and then click
312. nes 9 6 4 Fixed Data Provides methods for forcing ventilation conditions along an airway to be a required value Fix Temp WB DB Allows wet and or dry bulb temperature of the outlet air from the airway to be fixed to a value This forces the heat simulation to adjust the air temperature from any previous simulated heat temperature upstream to the fixed values The corresponding heat and moisture values required for the transition will be calculated and reported after simulation This function may have several useful functions e To adjust air temperature to a known value at a certain location without having to modify simulated results above this location e To predict the heat or cooling required to condition the airflow to the fixed temperatures The INFO tab will provide this information after simulation Hint Fixing the air temperature requires an adjusted to both sensible and latent heat content of the air Entering the wet and dry fixed values as the same temperature forces the simulation to assume a pure refrigerative condition which is converted to sensible heat and condensation instead of the normal sensible and latent heat calculation This is useful for determining refrigerative loads required for producing particular airway conditions Note that there still may be some residual latent heat reported for the airway due to strata heat and moisture transfer Diesel Emission An optional value used for Diesel Particulate Matter s
313. ng kW is set by the user not the input power this setting helps Ventsim calculate the total electrical power a model consumes COP normally varies from 2 5 to 5 0 refrigeration power vs input power and is dependent on the plant design and the input and output temperature parameters to the plant Direct simulation of these parameters is beyond the scope of Ventsim simulation Ventsim Visual assumes any item placed in an airway is simulated at the icon location For this reason placing a bulk air cooler in the middle of a shaft would assume the bulk air cooler is located half way down a shaft which in most cases would clearly not be the case This assumption would result in slightly differing air densities and air temperature than would be the case if placed on surface Ventsim Visual User Manual Page 193 20 4 2 What portion of the air is cooled It is recommended that for fans and thermodynamic items the icon be placed where the simulation is required to be performed or alternatively a short airway segment vertical or horizontal is placed at the top of a shaft airway for the cooling infrastructure This will force the program to use surface conditions for the device Ventsim Visual assumes a airflow within an airway is equally cooled by a refrigeration or heating device If only part of the airflow is actually cooled and the other part mixes downstream because of condensation of the split portion the mixed airflow results m
314. nit can be added during simulation Where a starting and ending value can be entered in the dynamic event the simulation will linearly range the values between the starting and ending time during the simulation WE Sea Event Name FIRE ESCALATES Time Range sec 6002 gt 1000 Resistance Gas Linear Emission 0 00 gt 0 00 100 Fire Wood do ll Si Hoat Diesel 25 id PVC Rubber y 10 Temp Start 0 gt 05 E Burn Rates 5000 gt 8000 kg hour Temp End E HC H e ozume DEI gt 87 Ventsim Visual User Manual Page 210 Multiple events can be added to the same airway by subsequently clicking NEW or by clicking COPY to duplicate and modify existing events Events can be added in any order or out of sequence as long at the time ranges specified for each event are correct 105 1 e Big Flre Starts Big Fire Contin Big Fire Ends 23 4 2 Adding Monitors A monitor is like a sensor that records a range of data during the dynamic simulation such 23 5 1 Dynamic Simulation Settings as airflows temperature and gases Due to the huge amounts of data generated by a dynamic simulation only information at specific preset monitor locations is recorded While instantaneous simulation results for the entire mine can be viewed during the simulation only locations installed with a Monitor can show the complete historical range of data collected during the entire simulation
315. non n nono n orar n rra nononos 195 Figure 21 1 Diesel Equipment with DPM emissions in Preset Values EE 198 Figure 21 2 Diesel heat ANd DPM source placed in CIWAOY ssscesssessssesssseesssssssessssessssesssessssessusssssesestessssessasessusessusessusessseseasesuscsnsesusessesessueesaes 198 Figure 21 3 Example showing DPM simulation colouring through mine 199 Figure 22 1 Example above showing a single model divided into four 4 different Stages sscsscssceessesseesseessesssesssesssessesseettecessesssenssesssens 200 Figure 23 1 Chart showing a complex buildup of Carbon Monoxide complicated by reversing and recirculating airflows o o 217 Figure 26 1 Financial Simulator Output showing life Of mine airway Coste 235 FIGUIEZ6 2 Example OF GO FINGNCIAL Simula Uorn TADE iii A AAA NAAA AA AA AAA 235 Foure 26 3 Eege 238 Figure 26 4 High Cost Airways coloured to show ceorhy EE 239 Hgure 271 Setihe EE 241 Figure 27 2 Enter the starting elevation of the drawing edit plane sssssceesseesseessessesssesssessscsssessscescssscesseessesssessseesseeasesssessssesteenssenssensseessens 242 FIGUIE WE Ee te ele Ree ee e 243 Figure 27 4 Draw horizontal airways from the ramp DOSE EE 243 Figure 27 9 CONSTIUCEG NOT ELE A A A ES 244 FIGUIE 27 6 Drawmultiple levels FOF TC ONE ii 244 Figure 27 7 Edit the ainway to set the OWY SIZE AAA AA AENA en 245 FIGUIE 27 3 Adda Ted airl Ow LOE ON WAY AAA AAA TA AAA ATA EAS AA 245 Ventsim V
316. ns have only a Static Pressure curve then the simulation will automatically switch to the Static Pressure Method Static Pressure Method A more traditional approach is to use fan static pressure which assumes that fan velocity pressure is wasted and does not contribute to the system ventilation pressure and flow While this is not technically correct this assumption removes some of the criticality of defining accurate exit losses and while exit losses should still not be ignored the resulting simulation will provide a more conservative result to simulation estimates of pressure and flow The Fan Static Pressure FSP method ignores system exit velocity pressure losses and for a primary surface fan driven model systems there is negligible difference between the FSP and FTP methods as the FTP methods considers velocity pressure losses as part of the system pressure However where underground booster fans contribute to a significant portion of ventilation flow the difference between the two methods will increase To use this method all fan curves used from the database should have a static pressure component As with the FTP method the fan database form has tools to assist the user in estimating FSP curves if not available Mixed Pressure Method The mixed pressure method maintains compatibility with Ventsim Classic 3 9 which allows both pressure types static and total to be used for fans in models The mixed pressure method is simila
317. ns will be preserved and new fans made available for selection The fan list can be edited Replace Presets from the fan database or from the Menge Presets Presets spreadsheet C Optimisation Reference Graphics Once a suitable file is selected an option panel is displayed to allow the user to select various components they wish to inherit from the saved file Once loaded these components will become part of the existing file An option is provided to merged with existing presets for example the friction factors may be added to a list of currently used friction factors or they can simply completely replace existing presets Offers tools to assist with applying custom pictures to fans resistance or heat preset items in Ventsim TS Custom icons allow individual fans heat sources or resistances to have pictures of for example real installations placed over the default icons in the model To place a new icon picture in a model simply drag and drop a picture file from any Windows folder onto the icon in your Ventsim Visual model to be changed The default icon will automatically change to the new picture Ventsim Visual User Manual Page 37 5 1 10 File Tools Other tools that may be of use in managing custom icons include Export Ventsim stores compressed copies of any icon pictures in the model onto a hard drive location that can be accessed from a Windows folder View Shows the Windows fold
318. nsors Info Notes Fans Options Fan Configurat FIP FSP Paralle Fix Flow 50 0 m3 s eries Limit Flow Y _ 50 0 mar Self Clos Fix Press 0 0 Pa 100 Fix Flow Equivalent resistance 0 08097 Deere lace 100 9 Da Figure 27 8 Add a fixed airflow to the airway Self Close Ventsim Visual User Manual Page 245 13 Adjust the shaft diameter until the required power constraints are met Ensure you simulate the model between each adjustment In this case a shaft size of 2 5m was found to produce the desired result The required duty point is 976Pa Total Fan pressure 150m3 s with a fan motor size of 288kW and an electrical power consumption of 303kW Fan Configuration FIP amp FSP a 2 Parallel Fix Flow IW 150 0 ois Series Limit Flow DI 150 0 mar C Self Close Fix Press IT 0 0 Pa 100 RPM Fix Flow Pressure 975 8 Pa Collar TP Flow 130 0 mvs Air density 1 20 kom Power 238 2 kW shat 303 4 kW electrical Coste 265 755 5 Individual Fan Data Combined Fan Data Figure 27 9 Use the Edit Info to view airway flow pressure and power 14 To perform a stench gas simulation place a contaminant in the upper decline with the Edit Box Set the contaminant to a strength of 100 and run the contaminant simulation The colour display will initially show a strength of 100 is spread all through the mine which is to be expected as the decline is the only source of fresh air Change t
319. nt adjustment to different airway sizes that in most cases will be accurate enough for selecting suitable sizes Sim Check this box to include the airway size in the simulation Airway sizes that are not reasonable or which do not deliver sufficient airflows should not be included for use as they can distort the graphs to excessive ranges Fixed Cost Many airways such a shafts have an initial setup cost to establish the mining method This option is included to allow this to be factored in to the overall airway mining costs It is applied only once for the airway or group of airways selected not applied to each individual airway In most cases horizontal development will not have a fixed cost applied against it Variable Cost The cost per unit length of development or mining Using this value Ventsim Visual calculates total mining costs based on the length of the airways selected Mining Cost Total cost of mining the airways Ventsim Visual User Manual Page 236 26 1 2 26 1 3 26 1 4 Financial Simulator Outputs Quick Select Financial Optimisation Financial Simulation Global ADVANCED Fan Cost Cost of the capital cost portion of fan infrastructure required to produce the ventilation flow Note only the portion of fan cost related to providing ventilation for the selected airway will be used Selected Annual Vent Cost Cost of ventilating selected airways for one year Note this is only the frictional co
320. nts and directions without having to simulate the model For large models or models undergoing extensive modifications it may be preferable to turn this function off as it will slow down editing and view functions Use compressible airflow simulation techniques Compressible airflow has a significant influence when simulating deeper mines In deeper mines greater than 500m or when heat simulation is used it is recommended that compressible airflow be set to True When set to True Ventsim Visual will assume compressible air and adjust air densities volumes and fan curves according to airway depth and corresponding density In the Advanced version temperature effects on density are also taken into account when Heat simulation is sun in conjunction with air simulation Airflows and fan curve performance after simulation is shown according to the density of air at the location of the airway Enables the simulation to adjust the friction factors to the local airway density As resistance is a factor of friction this will in turn adjust the airway resistance value This setting is set to YES by default Ventsim Visual User Manual Page 132 Density Adjust Resistance Factors Fan Reverse PFactor Fan Reverse QFactor Ignore Warnings Iterations Maximum Simulation Pressure Mesh Surface Priority When set to YES all preset friction factors are assumed to be specified at a standard density of 1 2kg m3 If compressible airf
321. nual Page 208 23 4 1 Adding Events the model into small independent cells which move freely around a model mixing with other cells at junctions Each airway may be broken into dozens of cells creating potentially hundreds of thousands of cells for a large model and each cell independently contains information on gases heat moisture and density at that location within the airway The cells are moved around at directions and speeds calculated by the global airflow simulation a Hardy Cross simulation based on compressible flows and density driven natural ventilation Because simulations for VentFIRE are assumed short term normally less than 24 hours heat transfer to and from each cell from rock strata is calculated by the radial heat transfer method but with strata heat transfer modified by the assumption of exposed rock boundary temperatures at a long term aged average coupled with a very short time Gibson s algorithm constant to accelerate heat transfer to and from the immediate rock boundaries during the fire simulation A shell of exposed rock at a customisable defined thickness is allowed to heat or cool during the fire event from the airflow however heat transfer beyond this exposed shell volume of rock into the greater surrounding rock mass is ignored during the short term simulation As each cell of air passes over a fire oxygen from the cell is consumed based on defined fuel properties at a defined combustib
322. oad selected components from an existing file Ventsim Visual User Manual Page 36 5 1 8 5 1 9 Inherit Icons Save Defaults Saves the settings currently loaded in memory to the defaults file These will be loaded automatically next time the program is run Restore Defaults Restores the defaults file to the original file created when the Ventsim Visual program was installed Adopts selected attributes from another model Ventsim Visual files contain many different components such as fan databases file and simulation settings level and layer database and many other options tert Attributes EE Instead of setting up new parameters f del th t b Presets Settings or a model ese cSmponen S can e F Fan Database PI Airway Defauits loaded from an existing file without ee EE R e e Saved View Colour Palette deleting the airway data in the current O file Preset factors Conversion Settings C Resistance E Program Settings Hint Fans from other Ventsim Visual C Friction Factors E Flow Simulation files can be used in your existing files E Shock Losses E Heat Simulation by inheriting and combining the fan Heat Presets E Contaminant databases The simulation file fans F Rock Presets El Environment inherited will only be added if no El Mine Levels F Graphics existing fans exist with the same name F Wew Layer F Others The merge option will ensure all the current model fa
323. od uses natural ventilation pressures to also induce flow although this is entirely derived from heat and density air changes throughout the mine It is possible to build a ventilation model with airflow driven entirely by geothermal heat or evaporative cooling however the simulation results can sometimes be unreliable due to changing airflow and pressures continuously affecting natural ventilation pressures A fan can be selected to simulate flow in a model Fan curves in Ventsim are automatically modified for local air density in a model and therefore may not match the original curve which may be at a different density Power efficiency and the fan duty point are calculated and provided in the EDIT box See the FAN section for further information Fixed airflows can either be used to simulate the effect of a fan or for forcing airflow into parts of a model to reproduce observed flows In general unless estimating the requirements for a fan the use of fixed flows to reproduce observable underground airflow is generally discouraged at it may adversely affect other parts of a model and does not provide a realistic behaviour for changes in underground model systems In many cases it can mask real problems with the model construction A fixed flow will force Ventsim Visual to calculate a pressure required to induce flow to the set amount This pressure can be substantial if the airflow needs to be pushed through a high resistance Conversely t
324. odel Similar to the Open command this may be useful for joining separate modeled areas of the Same mine Caution should be taken however as duplicate branches are not immediately checked when the models are merged duplicate branches will be subsequently be deleted if an attempt is made to simulate the model Saves changes made to the ventilation model If the Ventsim title bar shows that the model is untitled the user will be prompted to select a name before the file can be saved Saves the model but gives the option of saving under a different name Ventsim can be saved in one of two formats The default format in the VSM file which is the standard file format This format is highly compressed and cannot be read by other programs Ventsim Visual files can also be saved as a Textformat This format follows the standard TAB separated values format and can be loaded by programs such as Microsoft EXCEL WORD or ACCESS The internal contents of the file can be viewed modified and resaved as a Text file The Text file can be reloaded into Ventsim Visual providing the basic structure and the HEADER and FOOTER tabs remain the same Enables a common settings file Master File to be linked and shared with multiple Ventsim Visual files Master Files replace the Template function used in Version 1 of Ventsim Visual Master Files store a user definable selection of shared settings for example resistance and friction factor preset val
325. of the critical range 32 2 Errors Errors will generally halt a simulation process and must be corrected before a valid simulation can occur An airway set as restricted reverse in the Edit box was attempted to be reversed by the simulation As a result the simulation is halted This function is designed to warn the user about airways which should not have reversed airflow To remove this error simply unclick the option in the Edit Box for the airway An design in a netwok has resulting in a huge buildup of pressure beyond allowable levels This causes the simuliation calculation to corrupt and breakdown Because Ventsim uses somes of the results of previous simulations for current calculations for example fan pressures are used to help calculate air density this may corrupt future simulations as well Allow Ventsim Visual to automatically reset the model The model can also be manually reset from the Tools Menu The cause of the pressure buildup should be investigated It Ventsim Visual User Manual Page 272 32 2 3 32 2 4 32 2 5 32 2 6 32 2 7 32 2 8 32 2 9 32 2 10 Duplicate airway Resolution Fixed flow cannot be achieved Resolution Fix being over restricted Resolution operating fan blocked Resolution convergence problem Resolution temperature outside allowable range Resolution heat estimation usually stems from overuse or restriction of fixed airflow or t
326. ompatible files Provides a utility to export Ventsim centrelines text and solid graphics to a DXF file for importing into other CAD software The colours and text exported will be set to the current screen colours and text Different items can be selected for exporting They will be placed on different DXF layers so they can be turned on or off independently in the CAD program Note that any airway ventilation attributes will be lost during the export process and DXF files cannot be re imported back in to Ventsim as ventilation models Ventsim Visual User Manual Page 42 Export to DAF Export Options Data Text Size enter 0 none Node Text Size enter 0 none Airway Text Size enter 0 none Node Size enter 0 none Arrow Size enter 0 none Export tems Visible Airways Only Airway Solids Centrelines E Name Text Data Text Nodes Jl References Figure 5 5 Export to DXF Options 5 1 15 5 1 16 5 1 17 5 1 18 Provides a utility to separately manage any imported y rr E graphics reference Each imported object can be ap EM 0 separately coloured made transparent or hidden from the Wei oquena o p main view through the form options ACCESO_D1_327 0 ALAMBRE_ 2009 0 CERRADO HERMETICO 0 Select one or more graphics objects from the list with the CHEVE_87 0 i l i CHVE 21 0 mouse hold the shift key down to select multiple items leo 0 13 A
327. on Bq or pCi per second from ore piles for example that can usually be derived using a factor based on the volume of broken source ore material The formation of Radon progeny Radon daughters causes the harmful exposure of radiation to workers The Radon progeny calculation in Ventsim utilises a number of factors including the exposed rock surface area existing and newly emitted radon gas and existing Radon progeny activity in the atmosphere The result shows the potential radiation exposure in the atmosphere at different locations in the mine Because the decay of Radon gas into its various daughters can take some time after the gas enters the atmosphere Radon gas has a half life of 3 82 days the radiation emanation of Radon progeny is highly dependent on the time that Radon and its daughter particles are present in the atmosphere hence the higher progeny exposures can be some distance from where the Radon enters the atmosphere or where air is stagnant or slow moving For this reason it is highly desirable to limit the time that Radon loaded atmosphere spends in the mine Ventsim Visual User Manual Page 231 25 1 3 Threshold 25 2 1 25 2 2 25 2 3 Exposure Limits Radon Emanation Radon and Progeny Fixed Settings Activating Radon Radon progeny levels are normally specified in uJ m3 or air or more commonly in North America as a Working Level WL which was originally devised as a representation of an accepta
328. oniferous Clays Limestone Sandstone Dolerite Quartzite Potash Low Grade Potash High Grade Halite Low Grade Halite High Grade Table 12 1 Examples of Geothermal Gradients found in areas around the world Average Age The Default Age of an airway opening in years Airways without a specified age set in the Edit Box will be assigned this default airway age Establishing airway age allows Ventsim Visual to more accurately calculate geothermal heat flow into an airway Geothermal heat flow decreases with airway opening age Wetness Fraction The default fraction of airway rock surface that is wet Most rock surfaces underground have some degree of moisture The wetness fraction defines what average portion of rock Surfaces are considered wet A value of 0 01 would define a very dry airway while a value of 1 0 would define a fully wet airway This value will be assigned to airways without a set wetness fraction from the Edit Box and directly affects the amount of moisture available to evaporate into the air passing the rock surface Rock Density The default density of rock underground This value is applied to an airway if it has not already been set in the airway Edit Box Rock density is a property which describes the mass of rock per unit volume Rock density is used by Ventsim to calculate the thermal diffusivity of rock material Rock Density is not required if thermal diffusivity has already been set If this value is changed the u
329. ons and settings Many of the main menu bar function are duplicated in the toolbar buttons File Edit View Savedwiews Run Connect Tools Settings Window Help 5 1 File Menu Erases the model currently in memory An option is given to save any unsaved changes from the current model The previously used Level Layer and Fan Database will be retained for the new model The New option closes the model and load up the system startup defaults whereas the Close option closes the model but retains the previous model settings and defaults Loads a pre saved model You can also open Ventsim Visual files by dragging file icons from your Windows folders onto the Ventsim Visual screen Ventsim can open a number of different formats including Ventsim Visual Ventsim Classic and provides limited functionality to load VNET PC files Ventsim Classic files are slightly different in structure While good compatibility should be retained when loading these files it is always important to check and validate the model to ensure no significant changes have occurred during the transition from Ventsim Classic to Ventsim Visual Ventsim can directly import VnetPC files and construct a workable Ventilation model from the file however full compatibility is not guaranteed Ventsim attempts to import all airway data fan curves and environment data however because of some fundamental differences in files formats and data used there may be differenc
330. oo many high resistance bulkheads blocking off a working part of the model and restricting flow balanacing Occasionally it may be due to airways not being connecting properly restricting movement of air which can be resolved with the Tools gt Filter gt Bind command An airway with te same entry and exit location as another airway has been created Allow Ventsim Visual to delete the duplicate airway An airway has a fixed flow placed in line with another fixed flow resulting in a conflict between the two flows or a fix flow is placed in a locaton where it cannot draw air Remove one of the fixed flows or ensure a path between the flows exists to balanced the flow difference Ensure there are no breaks in any airways leading to or from the fixed flow through which airflow cannot travel A fix flow encounters too much resistance to flow the required air quantity causing a massive buildup in pressure Check to ensure pathways before and after the fix are connected to the model or surface and can freely flow air and no blocked resistances are present in the pathways before or after the fix Airways that are not exactly connected cannot carry airflow While a no entry exit warning will normally highlight these airways if allow closed end has been selected then no warning will show and the problem may be difficult to find Try the wireframe mode with nodes displayed if this is a problem A fan has been placed in an airway thr
331. oresresereseresresereneee 219 239 2 EE 219 23137 CHOKING UIE ee 219 LIVEVIEW PREMIUM uta ada dds 220 24 1 OVERVIEW OP LIV EVIE VV acond 220 24 1 1 How Does Ventsim LiveView use the dato 221 24 2 CREATING LIVEVIEW DATA CONNECTIONS were aa 221 24 2 4 step Connect toa DATA SOUICE A Nene 221 2422 FOSUAG the Data SOUTE eii OO A O 224 212 35 Step a Mapping ees 224 24 24 Testing the Sensor Data TEE edd 225 24 3 MANAGING CONNECTIONS EE 225 24 4 DEENEN e ia ii asia a a ii dee 226 24 4 1 Set Sensor Simulation Opotions En 226 24 4 2 IMPORT and MODIFY SENSORS ccccccccesssccecssssccecesssccesssscsessssscsesessscscsessscseessscecsesssceeesssceeess 227 24 5 DISPLAYING THE SENSOR DATA car a A auc aoa E A e 229 24 6 COPYING LIVEVIEW CONNECTIONS TO ANOTHER MODEL EE 230 RADON SIMULATION PREMIUM ia oda 231 25 1 INTRODUCTION aunar ii 231 25 11 RAGON CONCA IAN a 231 252 ee ee ia dana 231 2541 3 Threshold RN ele Re lt 232 25 2 USING THE RADON SIMULATION FEATURE geeiert 232 E Podon dee EE 232 25 2 2 Radon and Progeny Fixed SCttinS En 232 252 35 ACAN ROTON EE 232 252A Simulang ROGON AAA EE 233 FINANCIAL OPTIMISATION ADVANCED ccssssccsssssscccssssscccccnssccccrsssccsesssnncossnscccccsssscccssnsncccconsccccossssecessssaccocenscccooes 234 26 1 FINANCIAL SIMULATION eeneg 234 26 1 1 Graph Select Financial Optimtser EE 235 26 1 2 Quick Select Financial Optimisation En 237 26 1 3 Financial Simulation Global ee 2
332. osure levels in mining environments The atmospheric concentration of a diesel engine emission is a function of the rate and concentration of the exhaust emission and the amount of diluting airflow around the equipment By placing an engine size and emission concentration in Ventsim Visual the program can use simulated airflows to calculate the resulting atmospheric concentration Regulators have specified either an elemental carbon limit or a total carbon limit for allowable TWA atmospheric levels of diesel particulates In North America 2008 a standard of 160ug m3 Total Carbon elemental organic carbon has been initially imposed while Australia looks likely to adopt a 100ug m3 Elemental Carbon limit Ventsim Visual User Manual Page 196 21 2 1 What is the actual released DP value Application in a Mining Environment Example Diesel Equipment emissions are usually specified as a particular matter PM level normally factored to engine output for example 0 15 grams per kilowatt hour of engine power This level includes elemental carbon organic carbon and other particulate matter such as sulphates As the atmospheric limits relate only to carbon emission care must be taken to either factor the emission rate to carbon levels accordingly or factor the final atmospheric concentration limit so that only the desired carbon levels are used elemental or total In the event the emission components are not known it is
333. ote that the simulated evase effect is theoretical only and will ultimately depend on the efficiency and placement of the design to produce the simulated effects in a real mine As with all ventilation structures there will be some efficiency and shock loss factors that will reduce performance from the theoretical calculation These should be considered when observing the effects of simulated evas Ventsim simulation assumes diffusers are 100 efficient however typically diffusers may only be 70 75 efficient Therefore it is recommended simulating a diffuser at only 75 of the design area of the actual diffuser size to account for this inefficiency Note that only the Total Pressure simulation method calculates lost velocity pressures This additional lost velocity pressure is added to the Fan Total Pressure requirements for the mine If Static or Mixed pressure simulation is used which will happen if fans with only Static Pressure curves are used then any calculated primary fixed or fan pressures will exclude velocity pressure and therefore be more representative of Fan Static pressures only Places a sudden restriction in the airway with an open hole equivalent to the specified area The resulting shock loss and resistance of the orifice will be added to the resistance of the airway Orifice settings are normally used to simulate the effect of regulators holes in wall partly open doors or other sudden restrictions which may occur in underg
334. ough which no air can flow As with fix stopped check to ensure restricting blocked resistances are not present and the airways before and after the fan can carry air The model cannot find a resolution in the model airflow balance Ensure fans are not running stalled or negated and no unusual pressures or flows exist within the model Temperature is increasing or being reduced beyond the allowable range Investigate what is causing high low temperatures eg high heat or refirgeration loads coupled with low airflows Ensure airflow is adequate for heat addition or removal amounts Reduce heat input if possible or increase airflow A general error in estimating thermal properties occurred This normally occurs where air error encountered temperatures or pressures are welll outside of the expected range Resolution temp estimation near rock surface Investigate what is causing high low temperatures eg high heat or refirgeration loads coupled with low airflows Ensure airflow is adequate for heat addition or removal amounts Reduce heat input if possible or increase airflow An error estimate transfer of heat flux from rock strata surface to airflow This may happen where an extremely low airflow exists or temperature or moisture values in the air are unusually high or low Where airflow is less than the error correction value in the air Ventsim Visual User Manual Page 273 Resolution 32 2 11 overpressure
335. ould be activated or simulated in the model can also be set Sensor Editor fo Sensor Definition 0 Sensor ID S5IL1 Behaviour V Activate Simulate Description Sensor Type Flow Sensors Airflow Volume Unit Type mies Metric Mapped Airway E Find Equipment Type Conveyor Heat Y Y Mobile Default Value 0 Alam High 0 Alarm Alarm Low 0 Alarm Specifying the Sensor If the imported data contains either the Airway unique number or columns for the X Y Z Location coordinates of the sensor then LiveView will automatically place the sensor information against the airway when imported If the sensor location is not defined in the imported data then the user must specify which airway the sensor belongs to e The EDIT SENSORS OPTION under the LiveView menu also allows the user to specify the airway the sensor belongs to by entering the Airway Name or Number e An alternative option to placing a sensor on an airway is to use the EDIT selection box to click on an airway where the sensor s is located and select the sensor name directly The Sensor option is currently a sub option of the GAS tab in the edit box Ventsim Visual User Manual Page 228 4 H m s SAF V1 a Tools PRESTO TELE vay vans eat otmen cas Dynamic 39 6ppm SCO1 NS 25 0 C SDBT1 23 8 C SWBT1 15 4 Yes NVP Yes airways 526 e An option is provided i
336. our of semi transparent edit plane sheet shown during vertical drawing operations Colour Text Data Colour of the airway data Text colours may need to be adjusted to provide contrast if the background colours are adjusted Colour Text Airway Colour of the airway text names and error messages Text colours may need to be adjusted to provide contrast if the background colours are adjusted Colour Text Node Colour of the airway node names Text colours may need to be adjusted to provide contrast if the background colours are adjusted Print to White Background Instructs the program to make the background white when printing a graphics model to a printer or saving the image to a file Selection Colour The colour of selected airways The default colour is yellow however sometimes this colour may not be as visible with lighter colour backgrounds Text Background The colour behind text on the screen if transparent text is not used Ventsim Visual User Manual Page 127 12 3 3 Controls Ventsim Visual Settings General El Graphics Background Colours El Controls snap Tolerance 10 Use 3D Mouse No EI Coordinates Grid North Orientation Custom Grid System XYZ Automatric Grid Centering Yes Coordinate Centre Elevation 0 0 m Coordinate Centre 2 or Easting 1 700 0 m Coordinate Centre Y or Morthing 1 300 0 m Coordinate Range Elevation 1 000 0 m Coordinate Range 2 or Easting 1 000 0 m Coordinate Range Y or Morthing 1 000 0 m Level Rang
337. owest combined cost is normally the optimised point in sizing Lifetime Cost of Selected Airways airflow mining E Mining Cost EI Vent Cost _ Fan Purchase Cost 1 250 231 Shaft 1 8 Shaft 2 4 Shaft 3 0 Shaft 3 6 Shaft 4 2 Shaft 4 8 Hora 5 4 Hora 7 2 Airway Type Figure 26 1 Financial Simulator Output showing life of mine airway costs Increasing airway size is the easiest way to reduce frictional pressure losses and decrease ventilation costs in a mine Increasing airway size however creates additional mining costs and this is further exacerbated by the time value of money which dictates that a dollar saved in mining costs now is worth more than a dollar saved in ventilation costs in the future Another factor to consider is how long the airway is required to carry air which affects how much ventilation cost can be saved in the future The financial simulator takes all this into account and simulates up to 10 different airways sizes for an airway or group of airways reporting the effect on mining cost and ventilation costs as an NPV net present value cost adjusted overall cost all Financial Simulator Data Input Selected Financials Network Financials Selected Airflows Network Aiflow Selected Selected Sel Network Annual Cost Lifetime Airflow Annual Vent Cost Cost avg Vent Cost Shaft 1 8 Rai i 8 18 Lamm 3 000 1 250 231 7 658 340 6 644 222 536 925 580 205 6
338. own measurements or to specify days and night temperatures entering a mine through the total period of dynamic simulation 23 6 Simulating Events e Make sure all events and monitors have been set and placed If they require modification then the simulation must the halted and restarted after the changes have been made e Ensure the simulation dynamic settings and combustible presets have been established e For FIRE simulation ensure that both COMPRESSIBLE FLOW and NATURAL VENTILATON simulation options have been selected Ventsim Visual User Manual Page 213 23 6 2 Before Each Simulation 23 6 3 Running a VentFIRE FireSim Simulation e Ifsimulation of GAS elemental density is required for example you want to simulate the relative buoyancy of methane or the heaviness of CO2 then ensure that the setting SIMULATION gt GAS gt Use Gas Density for Air Simulation is set to YES For most fire simulation this is not necessary e Ensure the simulation settings for Dynamic and VentFIRE simulation are set correctly The number of sub cells or the dynamic simulation increment should be set according to the accuracy of the required simulation output In the event that the base program settings are lost Chasm Consulting recommend the following parameters be used as a base o Dynamic Increment 1 second o Maximum SubCells 8 or more o Time Delay O unless the model is very small o Display Update Frequency 10 o Air S
339. ows due to dynamic changes in airflow affecting subsequent heat balance simulations This is discussed further in the Heat Simulation section If this problem impacts heat simulation providing natural ventilation pressures are not critical it is suggested to set to it to Fa se to produce a stable simulation FALSE Ignore natural ventilation pressures Where heat simulation is not required or natural ventilation pressures are not likely to be significant in a mine it is suggested that this setting be set to FALSE If set to TRUE and an airway is specified in the EDIT form with a FIXED DIRECTION Ventsim Visual compares airway directions before and after a simulation and alerts the user which airways have airflow that has changed direction during simulation If set to TRUE Ventsim Visual will perform a check on all up casting vertical or semi vertical gt 45 degrees airways The water suspension phenomena occurs on water droplets where the up casting air velocity friction is counteracted by gravitational forces forming a Suspended column of water droplets which can greatly increase shaft resistance and pressure This can only be overcome by reducing airflow velocity allowing water to fall to the shaft bottom or increasing velocity to carry the water out of the top of the shaft The exact critical velocity depends on shaft size and geometry as well as water droplet size and geometry of entry into the shaft The upper and lower limits a
340. password will be required e An optional data format field is available to assist in the import translation of data however if the data is typed correctly in the database this should not be necessary e The data connection can be turned on or off at any time with the STATUS button Access Excel or Text In some businesses companies may not want LiveView to connect directly to the sensor files database for security or performance reasons Instead a 3 party macro can be written in many systems for the data collection system to periodically dump the sensor data into a file which Ventsim can read ao Excel Data Source een status CON Name EXCEL Data Excel File H Business Wentsim LiveWiew maestrodata ds Worksheet Sheet15 Date Format Optional 28 908 or e Enter a generic name describing your connection If no name is entered the file name will be displayed in the connection list instead Ventsim Visual User Manual Page 223 e To connect Liveview to the file simply click on the file type Tab Access Excel or Text CSV or TXT and enter the file name The input forms will differ slightly depending on the data type e The MS Access option will require a table name and password if required and Excel options will require a worksheet name e The data connection can be turned on or off at any time with the STATUS button 24 2 2 Testing the Data Source i e p X To test the raw data conn
341. ply uncheck the fix check box When a fixed flow is simulated the program will calculate a required pressure and power to produce the fixed flow Where the fixed flow is less than what would normally be simulated the fixed flow acts as a resistance or negative pressure influence and restrict flow In both cases the results of fixing a flow will be displayed in the INFO box gt Selecting the D will recommend a fan if a fixed flow is present and has been simulated The program will examine the pressure and flow required to achieve the flow and then search the fans in the program database for a suitable match The program will consider up to 4 parallel fans as being a viable match and display them in descending match order To swap the fixed flow for a recommended fan select the desired fan from the list Restrict is similar to a fixed flow in that a certain air flow rate is targeted during simulation The main difference however is the restrict is designed to resist flow and provide an equivalent resistance If the restrict value is greater than what would normally be required to restrict airflow ie it boosts the airflow a warning will be displayed during the model simulation Forces the airway to produce a constant positive pressure equivalent to the entered value in the box A fixed pressure cannot be set when a fan is present and a fan will be removed if the fixed pressure is checked To remove the influence of a fixed pressure
342. possible location sources of Tools contaminants underground Report Smoke Places a smoke report in the airway Report Fresh Places a fresh report in the airway See Location Tool menu item for further information Ventsim Visual User Manual Page 109 9 7 1 Fan and Fixed Information 9 7 Information The information tab provides a list of detailed information of settings and simulated values for an airway The list may be copied to the Windows clipboard for pasting in another application such as Word or Excel This can provide a valuable tool for comparing changes in specific airways before and after simulation In addition a thermodynamic summary is provided showing conditions at the start and end of the airway 38 EDIT 1 airways 237 5 m File Select Airways Tools Airway Fans Heat Gas Dynamic Sensors pn Notes El Pressure Total Relative 190 8 Pa to 477 2 Pa Pressure Static Relative 271 7 Pato 0 0 Pa Velocity Pressure a Baro Pressures 107 5 kPa to 104 3 kPa l Pressure Change 5 Pressure Loss Wall Friction 1 549 8 Pa Shock Loss 0 0 Pa gt Natural Ventilation 36 4 Pa Sum Total Losses 1 586 2 Pa l Fans and Fixes Simulated Data Elevation 67 9 m 325 4 Wet Bulb 240 C 24 0 Dry Bulb 00 340 RH Moisture 0 0135 kg kg 43 1 0 0141 kg kg WRT Calculated 426 C 36 9 Sensible Heat 207 6 klis 187 ay Latent Heat 223 3 kis Copy to Clipboard Figure 9 12 Airway Information Tab
343. provide fresh air and remove noxious gases and dust we also must design a climate for people to work in Even if a mine does not have excessive heat concerns worker performance will always be best where sufficient cool air is available to efficiently remove heat generated from human bodies doing work duties Different ventilation strategies can impact on the underground climate and this chapter discusses how Ventsim Visual deals with different sources of heat and moisture and explains tools in Ventsim Visual to analyse and apply design changes to improve underground climates Heat comes from a variety of sources in underground mining If we begin with the heat provided initially in the fresh air entering the mine from the outside climate the following sources are important factors in what happens while the air travels though the mine e Rock Strata Dictated by the rock type and geothermal gradient the temperature and heat flow from exposed rock increases at depth e Autocompression As air travels deeper and is compressed under gravity the temperature increases theoretically by nearly 10 degrees C dry bulb per 1000m although this may be less if moisture is present in the airways e Diesel Equipment A major source in modern mines both heat and moisture are generated by diesel equipment e Electrical Equipment Fans pumps winders substation and electrical distribution system all distribute heat into underground workin
344. ptions as to what graphics details and colours to display The display manager contain five 5 tabs which change the colour display between data types and air layer and elevation types The Display manager can be displayed or hidden by clicking this icon G The Manager controls many of Ventsim Visual advanced display functions At the core of the manager is the ability to display any type of ventilation data as a colour range including the ability to hide or make transparent data outside of a set range Ranged Data The data which creates the colour legend is automatically ranged to fit the model data values It may occasionally require resetting if new or changed values are present in a model after a simulation for example or the values do not divide the colours as you would like The data can be re ranged by either manual typing in new values or allowing Ventsim to automatically choose new values by selecting the RESET button Display Ez Transparency level slider ____ for data outside of data range values Data range of airway data equally divided by airway numbers To manually change simply enter a new value in the box Upper and lower range limiters Hide or make transparent data outside of range At full extent no data will be made transparent even if outside of range Adjustable colours for each range To change a colour click the colour square and select a new colour from palette Recalculated colo
345. r ADD function P and set the view to Plan 5 Establish an initial working elevation by using the Set Edit Centre function under the View menu lit Saved Views Run Connect al Fit All Home 4 Show All End Jeal Reset Display Quick View Copy to Clipboard Ctri G Copy to Clipboard All Copy Hi Res Snapshot Ctrl Space Set Edit Centre Show All Elevations Chas ALL aware Set the cen Figure 27 1 Set the starting edit location Ventsim Visual User Manual Page 241 Original Coordinates New Coordinates X 1818 5 1818 5 Y 14954 El 1495 4 2 100 0 Hevation Ir Vector Offset Azimuth 0 0 5 x 0 0 Dip 0 0 m yoo Distance 0 0 E Z 0 0 Figure 27 2 Enter the starting elevation of the drawing edit plane 6 Draw a decline loop using the Construct Ramp function in Ventsim EC Draw Single Draw Continuous Draw Gradient Draw Coordinates Construct Duct Convert Centreline Convert Any Ventsim Visual User Manual Page 242 Initial Bearing Gradient ve down 1 7 Ratio Ramp Height 200 m Start 1621 7 1 436 4 100 0 m Clockwise ee keen enen Figure 27 3 Construct an initial ramp decline 8 From the ramp base use the ADD button looks like a pencil to draw horizontal airways across to a shaft location Add some additional detail if you like MMI A AS it AUN IS IST J OPE
346. r Manual Page 123 12 2 1 Airway Defaults 12 2 General r 8 Ventsim Visual Settings leJ 1 A Z E General O Airway Defaults Airway Shape Efficiency Fan Motor Efficiency Fan or Fix Shaft Fan Recommendation Pressure Factor 0 6 Friction Factor Drive 0 0120 kg m3 Friction Factor Shaft 0 0050 kg m3 Friction Factor Type Primary Layer Secondary Layer Size Area Size Height Size Perimeter Size Width E File Settings Auto Backup Auto Backup Timing Automatic License Simulate Airflow On Loading Simulate Heat On Loading License settings PZ en ae License settings LicenseSettings General factors describe default airway sizes and settings when first building a model as well as file saving and loading behaviour in Ventsim Various defaults used by Ventsim in establishing airways without defined dimensions Airway Shape Default shape of airway Efficiency Fan Motor Default fan motor efficiency to apply to calculated fan shaft power to estimate the electrical power absorbed by the fan motor In most cases it will be around 95 for direct drive electrical motors or as low as 80 85 for offset or gear drive fans Efficiency Fan Fix Default efficiency factor to apply to motor shaft power calculations for fixed quantities and fans without efficiency or power curves Friction Factor Default friction K factor to apply to new airways Friction Factor Tyoe The number of the friction factor type to use on a def
347. r dispersion rates for different blast and ventilation scenarios Once Ventsim simulation are calibrated with the blast results the factors can be more accurately determined and used with more confidence in other areas Ventsim Visual User Manual Page 181 The contaminant and explosive concentration and amount can be placed with the SMOKE button and can be changed in the EDIT Contamination box A unlimited number of dynamic sources can be placed throughout the model each with a different blast size and clearance rate to simulate a number of development headings and stopes firing simultaneously for example E a a o o E a E a E 3 o Explosive Gas Release The yield rates of explosive gas SESE MLE SE EEOC EEE EF EEE Settings release can be established in the FEF EEE EEF FSFE EEF FSFE ESE SE Contamination Simulation Time Second settings The default yield rates Y are based the number of kilograms of Carbon Monoxide release per kilogram of explosive blasted as measured by Orica This yield factor can be changed or made to represent other types of gases The concentration units entered can be changed to any concentration based unit eg ppm mg m3 etc in the settings The unit name can also be changed in the Settings gt Contamination menu section The simulation is activated from the Run menu or from the Contaminant Simulation side button access EXAMPLE Blasted development headings have been previously measured
348. r during error description The airway number may change as airways are added or removed from the model Airway Name The name of an airway branch The name can be entered in the airway EDIT box The name does not affect simulation but may assist the user in identifying or finding airways Node Name The name of an airway junction The name can be entered in the airway EDIT box Unique ID Number A unique number assigned to every airway that does not change when airways are added or removed As a result the numbers may not be sequential and may have large gaps in the sequence Shock Name The descriptive name of the shock loss on the airway Airway Type The descriptive name of the airway type set in the EDIT box Profile The descriptive name of the profile if set Friction Factor The descriptive name of the friction factor Primary Name The layer nane and number of an airway primary layer Secondary Name The layer nane and number of an airway secondary layer 29 1 8 Contaminants Spread Mix Contaminant simulated concentrations through a model The value is unit independent and is normally relative in concentration to the original set values Spread Time The time in seconds that contaminant takes to appear in airways downstream from the source The time is calculate by an average cross sectional speed along all airways It does not take into account the changing velocity profile or incomplete mixing at junctions Asa result it is likely in most
349. r hardware Most sensor communication system will have hardware and software interfaces that record and store sensor data within an industry standard SQL database or similar Ventsim LiveView is designed to access the data from the databases or data files not directly from the sensors For example sensors located in an underground mine will send data through a network to a data collection computer which will store the sensor data in a database Ventsim LiveView can then query the database and extract the data values as soon as they are stored in the database or even extract historical data if available In cases where companies may not like third party programs such as Ventsim accessing databases directly the database can also be set up with read only SQL Views or alternatively could periodically dump a data file into a TEXT or EXCEL format for Ventsim LiveView to access Once the data is extracted into LiveView the sensor data can be mapped and displayed onto individual airways The sensor data can be assigned to hold specific types of data for example airflow gases or temperatures If the data assigned a type then it is also possible for that data to be automatically used in a simulation For example a sensor gas value can be used to simulate the likely downstream gas concentrations from the sensor location With enough sensor values an entire mine gas distribution could potential be simulated and displayed in realti
350. r somewhere in empty space To activate this system every time an airway is drawn to allow manual adjustment or entry of airway ends select the pull down arrow on the ADD button and choose the Coordinates sub options from the button To activate the system when moving or copying simply click an existing airway end while in the Move or Copy mode A coordinate window will show and the coordinates or offsets of the airway can be entered The coordinate entry allow airways ends to be adjusted manually or by using a vector polar coordinate or a physical offset of the easting s northings and elevation End coordinate values are adjusted in real time as offsets or polar coordinates are adjusted To apply the change simply click OK when completed Ventsim Visual User Manual Page 30 4 5 4 Moving Airways Start Coodinates End Coodinates 406 9 506 3 Northing 1630 3 E 619 6 Elevation 1500 0 Elevation Vector Azimuth 962 Easting 3934 Dip 10 5 Northing 10 7 Distance 101 6 Elevation 118 4 a co EE Figure 4 6 Coordinate entry system Depending on where the airway is clicked with the mouse in Move mode either end or the entire airway may be moved If the ends nodes of the airway are connected to other airways they will be stretched to accommodate An airway can be broken away from a node by selecting it a small distance back from the node and dragging it away with the mou
351. r stages Staging is a great alternatively to creating multiple different Ventsim files that can quickly become out of date Because staging shares common airways then changes to shared airways on one stage will flow automatically to other stages 8 vemo mvo E zen nen Metal Mine with D _ AA de 2 E E vents a E Jann enen Metal Mine with D iii jet ie mm e File Edi View Saved vwess Run Connect Tools Settings Window Help f Fie Edi View Savedwees Run Conned Tools Settings Windo Heip p euc BOG ap AO oeo Dp PON Pp eu BOC oe O rennen SP On 22 9 AIO SE coords 3442 4 E 16563N 717 AFi uee Compressible Ves NVP Ves armes 374 Ol eeng 2094 4 1539 70 717 Ar simulation were Compressible Yes NVP Yes aemeys 194 CS A E ES A A AA File Edf View Siwvedweas Run Connect Tools Settings Window Hel D File Edi View Savedviews Run Connect vindow PEAD Eo AO re rra gt PA One a pps un D ac Did 07 duction BPs PHONE 8 vents im Visual JOAO Coords 3408 5 16232N 717 Ay simulation successtul Compressible Ves NVF Ves ewen 372 LAAJAA Coord 3265 3 2079 0N 217 Airsimulation succesful Compressible Ves NVF Yes airways 527 Figure 22 1 Example above showing a single model divided into four 4 different stages Ventsim Visual User Manual Page 200 22 1 1 Example 1 Multiple Stage Time L
352. r subsequent heat simulations will again affect the balance This imbalance normally reduces with subsequent simulations as temperatures and airflow changes reach equilibrium Ventsim Visual User Manual Page 143 Multiple pass iterations can be set which will automatically force Ventsim Visual to simulate the model a number of times to account for some of the potential imbalance This will significantly slow down simulation time Iteration values larger than one are usually unnecessary if a model has already been heat balanced or if the HEAT simulation button has already been pressed a number of times HINT Performing a multiple pass heat simulation may have value if the model shows some heat instability changes in temperatures between simulations Heat instability is often caused by unstable natural ventilation changes driven by conflicting changes in airflow strata heat and evaporation For example a heat source which causes an increase in temperature may cause an increase in airflow due to natural ventilation in subsequent simulations the higher airflow causes lesser temperature increase from the heat source which in turn reduces the airflow due to natural ventilation Evaporation from strata moisture may also causing conflicting density changes with strata heat density changes offset by cooling evaporation The process may then oscillate between solutions for each heat simulation As a final pass performing a multiple pass simulat
353. r to the static method in that it does not consider system velocity pressure exit losses Fan pressure curve types can be specified for each fan location in the model This may be of assistance if some static or total pressure curves are not available for the fan and the user does not wish to estimate a curve The mixed pressure method is considered to be the least consistent method to use and should be avoided if possible Ventsim Classic 3 9 models will be automatically imported into Ventsim Visual as a mixed pressure model Ventsim 3 will automatically select the pressure simulation method based on the type of fan curve pressures available in the fan database for simulation The type of simulation method used is stated in the RUN gt SUMMARY Fans used in Auxiliary Ventilation Duct Unless discharge losses are manually considered only Fan Static Pressure curves should be used for duct pressure and airflow calculations as the velocity pressure exiting the duct is considered wasted For this reason when a fan is placed in a ventilation duct Ventsim will only use the Fan Static Pressure curve If only a Fan Total Pressure Curve is available then Ventsim will attempt to calculate the Fan Static Pressure Curve based on the fan diameter or area or if this is not available from the size of the duct the fan is place in Most fan manufactures supply one or both types of pressure curves Ventsim Visual differs from Ventsim Classic 3
354. ransparencies on off F12 Save As T Show Hide text data L Show Hide limited data Z Zoom Mode D Draw or Add airway mode E Edit Mode S Select Mode M Move Mode C Copy Mode B Block Mode for blocking unblocking airways R Reverse Mode for reversing airways Z Zoom Out P Perspective Orthogonal Mode Toggle W Toggle between Wireframe and Solids G Display Hide Grid N Display Hide Nodes A Display Hide Arrows I Display Hide Icons Ventsim Visual User Manual Page 276 34 Appendix Table of Figures FIGUFE ACE Veni Vrud Main VINO WEA AAA AAA ESA ACA ARE ACERA AE AAA 24 Figure 4 2 The Edit Plane shown with the SHIFT key Dressed scesscsscresecressosessossesescessesessesesneseoneseeteseoucsscncescscescssescevesceseenesecuessenessoneevencsseuseneses 28 Figure 4 3 True Vertical Line showing top and bottom airways lining up 28 Figure 4 4 True Vertical Guide Line helps guide a shaft vertically into the airway below E 29 Figure 4 5 Picture showing inclined airway being drawn down EE 30 FIQUIC A 6 Coordinate te E EEN 31 Figure 4 7 Example of copying a selected group Of GIFWAYS EE 33 Foure EE FIE ORHON a A a 36 Figure 3 2 Pe Security QDUONS EEN 38 Figure 5 3 An example of a Ventsim Visual Text File Loaded into Microsoft Excel 39 Figure 5 4 Import Option form Showing DXF IMPORT ODIOS iii a a ii 40 Figure 5 5 EXport tO OXF ODO a Ee 42 Fig re 5 6 Reference Graphics ee 43 Figure 5 7 Automatic License Activation AN
355. rative cooling the dry bulb air temperature is decreased while air moisture content in the form of water vapour increases as latent head resulting in net zero energy change Once evaporation occurs however the cooler ambient air temperature may be more receptive to heat transfer from rock surfaces resulting in increasing wet bulb and dry bulb temperatures downstream from the transfer point Examples of water addition to airflow may be e Dust suppression sprays e Evaporative Cooling e Conditioning of air for simulation e Water can be injected into airflow using the Point or Linear moisture source function in the Heat input sheet on the Edit form Dust suppression sprays are often used on dusty roadways at stope draw points or on conveyor belts or crushers Water sprays directly increase the water content of air through increased evaporation from fine water particles as well as wet surfaces around the sprays In many cases however the uses of sprays is often sporadic and does not represent a steady state flow model For sporadic sprays a better solution to applying moisture to the airflow in a dust suppression area may be to increase the wall wetness fraction to closer to one 1 This will assume the area remains wet and also proportionately alter moisture addition depending on the airflow quantities in the area Caution The amount of water capable of being applied to airflow will be limited by the amount of airflow in the airway If too
356. rder to correctly input and interpret the program functions and results The solutions and methods presented in Ventsim are based on the published work of many talented individuals and research organisation over many decades Many excellent texts and papers exist for mine ventilation not the least which is the late Malcolm J McPherson s Subsurface Ventilation and Environmental Engineering from which Ventsim Visual draws much of the methodology for thermodynamic simulation Finally special thanks to Dr Rick Brake for his assistance during the development of Ventsim Visual Page 4 Table of Contents SECTION 1 PROGRAM FUNCTIONS 1 VENTSIM VISUAL VERSION 3 WHAT S NEW sivvcscssscocsesiscsascuvevuascebicnsnasseceuiesssusaseonscsssevs ERA 16 2 VENTSIM VISUALS AN INTRODUCTION so scsissssscstsssssensnsscnsusssassesssnsssenanaoosessssasscsdsnsssenssesonseasusssssssvessessieasscessuasasssivess 17 3 VENTSIM CLASSIC TO VISUAL GUIDE Guia 20 4 THE VIEW TT E 24 5 el IERT 34 6 THE VIEW TOOLBAR avoir O A O AE AA E 70 7 THE ACTION TOOLBAR E 73 8 THE DATA TOOLBAR nuria 86 9 THE EDIT BOX An ono E E 90 10 THE POPUP CONTEXT MENU AA e e CO O e noo O Oar iN a auaa raai 115 11 PPP o o Eesen 118 12 SETTINGS ices NS AAA AS RAEE TRIAS AAA 122 13 HEAT ASSISTANT adas 147 14 FANS init 152 SECTION 2 PROGRAM USE 15 BUILDING A VENTILATION MODEL ona aaa A A AS E 158 16 AUXILEIARY VENTILATION AND DU Tucci 170 17 CONTAMINANT SIMULAT
357. re location thereby losing some cooling effectiveness along the travel route 2 Underground Spot Cooler Plant A refrigeration plant or machine placed underground normally only provides spot cooling for part of a mine The simulation requires both a refrigerative and heat source to be separately placed in the model representing the cooling produced and the heat rejected The heat rejected must also include the input power to the plant Spot coolers have the advantage of only cooling the air required but the disadvantage of requiring a separate exhaust airway to remove the heat rejection In addition spot cooler tend to be smaller due to underground size restrictions and are more difficult to run and maintain 3 Underground Chilled Water The refrigeration plant is based on the surface but the chilled water refrigeration exchange is location underground In this case only a refrigeration source needs to be simulation Chilled water systems have the advantage of providing cooling only where needed but the disadvantage of requiring potentially large volumes of water to be pumped and distributed through a mine Finally the ratio of the refrigeration power heat exchange generated versus the electrical or mechanical input power is called the refrigeration coefficient of performance COP and is specified in the SETTING gt HEAT Although this factor is not directly involved in the simulation process the final Refrigeration Exchange cooli
358. read of gases and change of ventilation The mine would also like to test of scenario to see what effect closing some doors and turning off fans will have on the fire and smoke spread at a pre determined time into the fire A VentFIRE simulation can be easily established to e Calculate the gases temperatures and change of airflows and whether they reverse produced by the truck fire e Show the atmospheric gas levels at various points through the mine including areas such as crib rooms or refuge bay where people may congregate e What will happen if fire doors are closed 15 minutes after the fire starts and some fans are turned off and whether this will limit smoke spread or gas concentration through the mine A mine would like to model the effects of reducing mine refrigeration output during cooler night time hours to reduce power consumption Even though this has nothing to do with fire a VentFIRE simulation can be established to e Dynamically vary the day and night time air temperatures flowing into the mine e Dynamically vary the refrigeration output at different times during the day and night Ventsim Visual User Manual Page 207 23 1 3 Example 3 e Monitor the effects of these changes on air temperature and humidity deep in the mine at different locations A mine would like to model the heat from intense diesel engine activity that occurs during various mining cycles to see what range of temperatures will be exper
359. reframed Only Metric or Imperial Coordinates Offset X Y Z Convert 2D Scale Ventsim Visual will search a DXF file for both line strings and solids as well as layers within the DXF file The import options indicate what action to take if these items are found Layers The right hand column lists available layers in the DXF file which may be imported Only select the layers required to be imported into Ventsim Centrelines Centrelines lines or polylines can be either converted to ventilation airways which will carry airflow within a ventilation model or simply as a reference graphical line string which will not affect a mine ventilation model but which can be used to help guide and place manually constructed airways Disabling this function will tell the program to ignore any line strings found Adds the new imported data to the current model Tells the program NOT to build airways out of centrelines but simply import as a graphical reference A centreline can be converted later to an airway using the Add gt Convert function Surfaces or 3D solids cannot be directly converted into airways unless a convert all option is attempted however 3D data can provide a useful reference to manually developing Ventsim Airways In addition it can provide an important visual aid to viewing ventilation models within an actual mine environment Disabling this function tells the program to ignore and not load any solid grap
360. rence in height between the airway elevation and the defined surface elevation in the settings Figure 9 5 Further Airway Options Seomdsrylajer Miscellaneous v Allows Ventsim Visual to assume the airway is a dead end without connecting to other airways or to the surface Examples of this may include a dead end blind developing heading or undeveloped heading The simulation process will assume this path is blocked and allow no airflow along the airway If this settings is not used a simulation will report a no entry or no exit error Groups any selected airways into a single selectable group that can be selected with a single Select click Individual airways can still be individually edited by clicking on them directly with the EDIT button instead of using SELECT first or by holding the lt CTRL gt key down while selecting Grouped airways are a convenient way to collect airway systems together Ventsim Visual User Manual Page 95 Exclude Fix Direction Show Data Gradient Diffuser Orifice Air Type for example shafts or decline sections so they are easier to select and edit simultaneously It has no effect on simulation Excludes the airway from the simulation process Any errors or problems with the airways are ignored during simulation and no flow is allowed through the excluded airways Any non excluded airway which joins with an excluded airway will be assumed to be blocked This function
361. result significantly however smaller leakage intervals will theoretically give more accurate results but will increase the clutter and complexity of the display For longer ducts a minimum of 50m is suggested Offset Specifies where the duct will be built in relation to the airway It is advantageous to build the duct outside of the main airway as it is easier to see and manipulate For example if the main airway is 5m high then a Z Offset of 5m will place the duct at 5m above the centreline of the airway Do not use an offset of 0 0 0 as this will overlay the duct on the airway centreline and will simulate correctly Build Duct starts the duct building process A duct and leakage paths are place on a single group to allow the system to be selected with a single Select click in future Figure 16 1 Example of duct built Modify Duct modifies existing se ected ducting with any new factors entered into the duct builder Note that the leakage intervals cannot be modified If this is required the duct should be removed and re built Remove Duct deletes any existing se ected ducting from the model If normal airways are also selected then this function will only delete ducting and leakage paths Hint Things you may want to do next Place a suitable fan at the start of the ducting airway Consider placing an obstruction in the main airway if the duct is significant in size and airflows along the main airway are high 16 2 Apply
362. ring a fire simulation again from the SETTINGS gt DYNAMIC to allow the air to travel a certain distance airflow momentum before a change of airflow is established 23 9 VentFIRE Limitations A number of limitations need to be recognised when using VentFIRE Ventsim Visual User Manual Page 218 23 9 1 23 9 2 23 9 3 Fire effect simulation not fire chemistry simulation Rollback Choking Limitations Fire chemistry is not simulated apart from oxygen deficiency Simulated results are only as good as assumptions entered into the program Gas levels are highly dependent on assumed yield rates of combustible materials and should not be generally used to indicated safe gas level and dangerous gas levels ANY abnormal gas level simulated by VentFIRE should be considered potentially hazardous VentFIRE does not currently consider rollback where heat and fumes can travel along the roof in the opposite direction to the airflow for some distance back from the fire Rollback distances are highly variable and depend on fire intensity the slope of the airway and the velocity of the opposing airflow The initial expansion phase of the fire will produce a non mass balanced model where the mass flow of cold air exiting an airway may be greater than the mass flow of hotter air entering the same airway In other words for a limited time the lower mass flow of hotter air pushes out a higher mass f
363. rm dynamic simulation term that this function is designed for the assumption of the rock boundary layer achieving a stable temperature produces reasonable results To adjust for longer term exposure during dynamic heat simulation Ventsim creates a boundary layer of rock of a predetermined thickness that is allowed to store or release heat during simulation The settings in the DYNAMIC gt VENTFIRE section provide some level of control over the way this function works on the mine atmosphere For more detail on this function see the VentFIRE section of the manual For complex dynamic heat simulation the VentFIRE module is recommended as it allows pre programmed heat and temperature changes to be included in the modelling rather than manually pausing and changing the simulation For further information on steady state heat or dynamic heat simulation see the THERMODYNAMIC SIMULATION chapter or the VENTFIRE section Warning Due to the nature of short term dynamic heat simulation it may not predict exactly the same results as steady state heat simulation If this is required the SETTING gt DYNAMIC gt VENTFIRE option for Dynamic Rock Age may need to be increased however this will impact on the Thermal Flywheel effect during simulation Ventsim Visual User Manual Page 184 19 1 1 19 1 2 Inline Concentration Method Injection Method 19 MULTI GAS SIMULATION Advanced Ventsim Visual Advanced Gas S
364. rmal Gradient 12 4 2 Examples of Rock Properties Ventsim Visual User Manual Page 139 ze eso mm os Table 12 2 Metric Examples of Airway Rock Physical Parameters mue Sg mn Table 12 3 Imperial Examples of Airway Rock Physical Parameters Warning These are examples only Rock characteristics vary widely for different rock types and locations Where possible characteristics should be measured by laboratory analysis 12 4 3 Explosive Contaminant Density The gas density of the contaminant gas of concern from the explosive reaction For example if Carbon Monoxide is the main gas of concern then a gas density of 1 16 kg m3 could be used Ventsim uses this density figure to convert the yield mass into a volume Contaminant Yield The mass ratio of contaminant of concern produced per equivalent mass of explosive Amount detonated For example if Carbon Monoxide was the gas of concern in an explosive detonation tests by Orica reveal that approximately 0 015 kg of carbon monoxide is produced for every 1 0kg of explosive detonated Therefore the contaminant yield for CO is 0 015 Further information regarding contaminant simulation can be found in the Run_ gt Contaminant section Ventsim Visual User Manual Page 140 12 4 4 Fire PREMIUM Combustion Efficiency Equivalence Ratio Shift Limit Lower O2 Limit Upper OC Maximum moisture release rate Residual Heat Rock Absorbtivity Age Rock Boundary Heat Flux
365. rns on the fan or fix during simulation enabling the item to influence airflow within the model OFF Turns off the influence of the fan or fix during simulation The airway and model will behave as if the fan or fix is not present Reverse Button Changes the direction of the fan or fix pressure This is a convenient way to reverse the direction of airflow and performs the same function as using the REVERSE button on the main toolbar Note that this is not the same as pressing the COUNTER ROTATE button which forces the blades of the fan to rotate backwards at reduced performance Auto Close Closes the airway when a fan or fix is turned off Many actual fan installations have a mechanical device which shuts off airflow when a fan is turned off or loses power The self closing option allows the simulation to reflect this If this option is unchecked airflow will be allowed to flow freely back through the airway as if the fan is not present Activating this option will close the airway preventing airflow when the fan is switched off Ventsim Visual User Manual Page 100 Fix Flow Restrict Fix Press Fan Name Number and Configuration Fan Pressure Curve TOTAL STATIC Counter Rotate Forces the simulation to produce an airflow equivalent to the value entered in the box A fixed flow cannot be set when a fan is present and a fan will be removed if the fixed flow is checked To remove the influence of the fixed flow sim
366. rom the display Levels level elevations outside of the selected ranges can be made transparent or hidden Layers primary and secondary layers that are not selected can be made transparent or hidden Zero Flows Airways carrying no flow can be made transparent or hidden 6 1 2 Move Toolbar Moves the toolbar to the left of right of the screen window dk 6 1 3 Hide Toolbar Hides the toolbar from the window To show the toolbar again RIGHT CLICK the mouse anywhere on the screen and select View Toolbar 6 1 1 Scale Toolbar Scales the graphics airway dimensions except for length on the screen For cluttered areas 10 this can be useful to decrease the relative volumes of the airway displays and make the graphics easier to see For very long tunnels the opposite effect may be desired and the scale can be increase to thicken the airways and make it more easily viewed This tools does not change the true dimensions or characteristics of the airway therefore simulations will not be affected It is simply a tools to improve clarity of the 3D models in the screen Ventsim Visual User Manual Page 71 Ventsim Visual User Manual Page 72 7 1 1 7 1 2 7 1 3 7 2 1 7 2 2 7 2 3 7 2 4 7 2 5 7 2 6 New File Open File Save File Reset Display Undo Redo Create New Window Show All Snapshot 7 THE ACTION TOOLBAR The toolbar allows quick access to commonly used Ventsim
367. rough potential different sizes The variable mining costs are defined in the Settings This function can only be used on a single airway such as a shaft or groups of airways with the same size for example a decline system Checks and reports on all airways within a mine model on their size suitability to carry the simulated air This is a broad function which utilises the default cost settings to determine to cost of airflow through each airway for the life of the mine The cost component costs are a relative mining cost and fan capital cost component and a lifetime discounted power cost to provide the ventilation The simulation will only report airways which are over restricted and potential cost savings exist by making the airway larger While smaller airways could also be more economical Ventsim ignores this option as this type of airway is usually sized for a certain means eg truck access and it would be distracting to report all possible size reductions To check individual airways for size reduction options it is suggested the Quick Select or Graph Select Financial optimiser be used or the Suggest button in the Edit airway form Ventsim Visual User Manual Page 237 26 2 1 Example Optimisation Results Total potential cost savings 266 524 5 479 423 Mine Capital Savings 5172 644 Fan Capital Savings 5573 304 Power Savings 172 6 kW 5 year discounted Annual Power Savings 151 236 Double click listed a
368. round headings It can also be used to simulate the effect of large equipment blocking an airway by entering the remaining area around the equipment as the orifice size Sets the type of air the airway is carrying for example fresh exhaust mixed etc The air type can be shown as a separate colour on screen by selecting a r type under the favourites menu on the Display Manager Ventsim Visual User Manual Page 96 K Ventsim Visual Blue_sky txt VentSim Demonstration Network File Edit View SavedViews Run Tools Window Help Jj Sy dl A E 6 Y Airflow v Quantity D P400 Exhaust 24 9 0 3 fresh air 3 6 Units m3 s Coords 3000 5E 2143 8N 850Z Figure 9 6 Example of use of fresh exhaust airway type colouring Hint Most mines have designated fresh and exhaust airways and may also have airways which may be designated as potentially either depending on production activities Ventsim Classic 3 9 defaulted to a blue red green colour scheme for these three types of airways Ventsim Visual uses these three air types but also has up to potentially 25 other types and colours which can be specified under the Edit Box Other air types could be set by the user as emergency access flooded vent duct etc Primary Layer Sets the primary layer type of the airway Once set primary layers can be independently displayed using the Display Manager The name of the primary layer can be changed b
369. rows Note that the size reduces in wireframe mode to improve display legibility In Solid mode Icons and Nodes will not be reduced smaller than the airway size Ventsim Visual User Manual Page 130 HEAR Font for Text Arial Unicode MS lcon Heat Text Yes Maximum Distance for Text 1000 Show Fan Description Yes Show Resistance Description Yes Text Scale Relative Wes Text Transparent Yes re a Font for Text Allow selection of the type of FONT to display on the screen Icon Heat Test Display text on icons with heat sources Show Heat Text with Shows the thermodynamic setting names on the airways they are attached to Airway Text Maximum Distance for Hides text beyond a defined distance from the display front For large models this can Text speed up display Show Fan Description Display text showing fan name description Text Transparent The background for text characters is shown as a solid colour or transparent Turning off text transparency can improve clarity of text graphics but will obscure the airway graphics behind the text TRUE Text labels backgrounds are transparent and show graphics under the label FALSE Text label backgrounds are solid and do not show graphics underneath In some cases this may improve the legibility of text Text Scale Relative TRUE Reduces the size of text labels relative to distance away from view camera This make close airways larger and more legible and distant airway text small
370. rway with no existing equivalent icon Hint Icon location can cause significant changes to fan performance on very long airways with elevation changes For example a fan place at the top of a 1000m deep shaft will perform very Ventsim Visual User Manual Page 32 differently to a fan place at the bottom of the shaft due to different density and pressure variations at each location Ventsim Visual Advanced will calculate the variations and simulate the fan at the location at which the icon is placed Ensure the icon is correctly located along the airway or use a very short airway segment for example a short extension at the top of a shaft to locate the icon where it is required to be simulated 4 5 1 Copying Airways Airways can be copied much in the same way as the Move function An airway can be grabbed with the mouse and dropped in a new location or the airway can be clicked and manually copied with new coordinates In addition a group of airways can be selected with the Se ect button or by drawing a fence around the airways and then clicking or dragging one of the selected airways Units m3 s Coords 4956 9E 1741 7N 993Z Simulation complete Figure 4 7 Example of copying a selected group of airways Ventsim Visual User Manual Page 33 9 1 1 5 1 2 New Close Open VnetPC Files 9 THE MENU BAR The main menu bar accesses a host of functions including simulation options and settings and viewing opti
371. s a picture copy of the current window in a new form window Static Views are primarily for referencing areas before and after simulation It may be useful in showing a sequence of changing ventilation simulation results by storing previous results for comparison with new results The form window defaults to 25 of the size of the normal view window but can be resized or maximised at any time to show full detail The static view forms can be renamed for reference or saved to a picture JPG file for future use in other software Static views are simply picture copies of the original model graphics and remain the same regardless what happens to a model after the static view is created They cannot be edited moved or rotated The number of static views created is only limited by the memory Capacity of the computer HINT Both the EDIT box and the FAN DATABASE form can also be reproduced as a STATIC view This is useful to provide a quick comparison between airways or model results before and after simulation changes To use this function simply RIGHT click the EDIT box or FAN form and select Static View Ventsim Visual User Manual Page 49 9 3 9 5 3 10 5 3 11 5 3 12 5 3 13 5 4 1 5 4 2 5 4 3 Set Edit Centre Show All Elevations Show All Layers Hide Zero Flow Hide Excluded Save View Delete View Saved Views Sets the edit grid and point of focus to a specified coordinate or elevation New airways
372. s dead ends resulting in no exit or entry errors If many of these can be corrected before starting an airflow simulation this will improve the ease of creating a working model To help tidy up models and correct initial errors a number of tools are provided in the TOOLS gt FILTER menu to bind disconnected airways and find duplicated airways Alternatively for airways which are disconnected use the toolbar move function to move the airway end onto the other junctions ends If this is done correctly moving the node after joining will then result in all airway ends moving simultaneously Under Tools gt Utilities gt FILTERING TOOLS BINDING Bind Nodes use a value up to 4 5m or more to bind ends that are close to each other Bind Junctions Binds loose nodes that are close to a passing airway which has no corresponding node or junction Bind Intercepts find and or join airways that cross each other but have no joining nodes SIMPLIFY removes a lot of the small airways and unnecessary detail In many cases importing a DXF files directly from a mine planning will create an overly detailed model file which will slow down the system graphics and simulation resulting in a more unwieldy model For example a nice smoothly rounded decline airway which produces many airway segments is simply not required for accurate ventilation simulation and in most case can be designed with less segments and detail The Simplify function in Ventsi
373. s in airways through the region and SIMULATE again after any changes Airway 90 Waming no exit connection Airway 167 Waming no edt connection Once 8 Airway 5974 Waming no exit connection Figure 27 19 Airways coloured by airflow Airway 5988 Waming no exit connection airflow eel is correctly established at this stage we are not no exit connection interested in establishing accurate airflows just no ext connection making sure air has an open connected pathway to follow then SELECT all of the airways which are still showing NO EXIT ENTRY warnings EDIT the airways and select CLOSE ENDS in the Edit Box Ventsim Visual User Manual Page 254 SIMULATE again No errors or warnings should show If they do repeat the search for airway error and simulate again The model is now ready to be correctly sized with all fans and ventilation controls established Select and change the airways and set them to the correct size Insert fans and control in proper positions If desired use LAYERS and text names to help improve accessibility to your model Ventsim Visual User Manual Page 255 28 1 1 Airway 28 1 2 Branch 28 1 3 TXT 28 1 4 DXF 28 1 5 Endpoint Start point 28 1 6 Friction cost 28 APPENDIX A GLOSSARY OF TERMS 28 1 A glossary of commonly used terms An section of underground tunnel defined by two end points An airway a tunnel or shaft that carries airflow
374. s will be used and modified between each stage then the airways can be copied from one stage then pasted in the same position on a different stage Using this method any airway can be modified without fear of changing airways on other stages Ventsim Visual User Manual Page 201 22 2 1 Setting up Stage Names 22 2 Using Stages HINT Please ensure you understand staging before create multiple stages with shared airways There is a danger that a user may make changes to shared airways forgetting that it may unintentionally affect other stages unless the modification is done to a unique airway only belonging to that stage By default Ventsim calls stages names Stage 1 Stage 2 etc Up to twelve 12 stages are available It is helpful when using stages to give stages meaningful names Staging names can be directly typed into the combo box on the main screen by pressing the RIGHT MOUSE button on the list To enter more detailed Stage names and descriptions the TOOLS gt STAGES menu in Ventsim can be used instead to change names This tool also allows detailed descriptions to be entered in the lower Stage window Settings Window y Fans Levels Spreadsheet In addition the order of stages can be moved up or down in relation to other stages by selecting the ROW and using the keyboard arrow key Click on the Sim Air and or Sim Heat to simulate the models when switching between Stages By def
375. se Multiple airways can be copied or moved by Se ecting the airways with the Se ect button or by drawing a fence around the airways while in Move or Copy mode and then dragging the selected airways or clicking one with the mouse coordinates Units m3 s Coorde 4967 7F 1800 4N 10067 Simulation camnlete Examples of Moving Airways Ventsim Visual User Manual Page 31 Units m3 s Coords 49620 17389N 9937 Units m3 s Coords 49552E 181L18N 9947 4 5 1 Moving Copying Icons e Upper left Airways are selected and then moved simultaneously e Upper right Airway junction is moved with all attached airways e Lower left Airway is broken away from node and pulled away with mouse e Lower right Airway junction is moved vertically by pressing shift while using mouse Simulation complete Units m3 s Coords 496186 18028M 9977 Simutation complete Units m3 s Coords 4967 7 E 17984N 10007 Icon placement is not normally critical however for fans or heat sources it can have some effect due to changes in air density and pressure along an airway The simulation will calculate the parameters and effects of an icon as the specific point it is located in the airway To move an icon within an airway simply choose the Move mode and select and drag the icon along the airway with the LEFT mouse button To move or copy an icon to another airway simply drag the icon to the new location Note that an icon can only be copied or moved to an ai
376. secondary layers To change an air type name right mouse click on the existing air type name and type in the new name Primary Secondary Layers Selects which primary or secondary layers are displayed on screen Layers are a way to show selected airways such as a decline system or a shaft system on screen while hiding other airways Primary and Secondary layers can be set to individual airways in the Edit Box To change a Layer name right mouse click on the name and type in the new name Names can also be changed directly from the airway Edit Box or in the Preset Box available from the Settings menu Ventsim Visual User Manual Page 89 9 THE EDIT BOX The edit box is a powerful tool required to manipulate and display airway attributes In summary the Edit Box can perform the following functions Tak com a Sala e Set airway attributes for airflows and pressure simulation es Yow ne rn orane e Set airway attributes for heat simulation MA e Set contaminant and gas attributes for airways eo e e Allow custom comments and information such as survey 9770 m results to be set for each airway ee a e Display working fan duty curves e Display airway information derived from simulation Se The Edit Box can be activated by clicking on an airway while in the View Editor Add modes selected from the main toolbar The Edit Box is divided into a number of TABS to allow quick access to each funct
377. sed effects of ventilation changes Using a new multi cellular simulation approach dynamic simulation is now performed in more detail speed and accuracy than ever before and for the first time ALL simulation methods Airflow contaminants DPM fumes gases and heat are now available in the dynamic function Finally a new highly specialised simulation engine called VentFIRE has been included as an optional extra for users who require programmable events driven dynamic simulation tool which includes fire combustion heat and gases This exciting addition allows users to simulate all types of heat and gases and programmatically makes changes to ventilation systems over time Complete emergency scenarios coupled as the module name Suggests with large fires can now be simulated complete with heat and gas predictions and changes to the ventilation circuit such as doors opening or closing or fans turning on or off can be made to examine the effectiveness of various emergency response strategies Welcome To Ventsim Visual Version 3 Page 16 2 Ventsim Visual An Introduction Ventsim Visual is the successor to Ventsim Classic which was first developed and released in 1993 and was widely lauded for its simple interface and graphical Windows based 3D wireframe approach to displaying ventilation models The relatively recent introduction of affordable 3D graphics hardware into everyday PC s encouraged a new approach with V
378. send the correct message to Ventsim to enabled Ventsim to reset the card and restore the graphics In most cases the screen can be recovered by using the VIEW gt REFRESH menu items In extreme cases the software may need to be shutdown and restarted Updating the graphics cards software drivers can often help in this case Alternatively disable the screen saver hybernation and allow the computer to simply turn off the monitor instead Anti aliasing does Only newer graphics cards fully support this image smoothing feature Older graphics cards not work is very slow Resolution Custom Icons cannot be used particular INTEL motherboard types do not support it Low power graphics solutions from ATI or NVIDIA may support it but graphics performance will slow No solution Install a newer vidia card which supports full screen anti aliasing or turn off anti aliasing in the settings Only newer graphics cards fully support custom icons Older graphics cards particularly INTEL may not have sufficient memory pointers to support the placement of potentially tens of thousands of icon images on the screen therefore support for these cards has been disabled Resolution No solution Install a newer vidia card Ventsim Visual User Manual Page 269 31 2 Software Problems Occasionally the screen will not display graphics as expected This can stem from a wide range of settings in Ventsim which may not be set correctly to display
379. ser will be prompted to allow Ventsim to auto calculate the rock diffusivity Rock Specific Heat Ventsim Visual User Manual Page 138 The default Specific Heat of rock underground This value is applied to an airway if it has not already been set in the Edit Box Rock Specific heat describes how much heat must be absorbed or emitted to raise or lower the rock temperature Thermal Diffusivity The default Thermal Diffusivity of rock underground This value is applied to an airway if it has not already been set in the Edit Box Rock Thermal Diffusivity is a property which describes the ability of rock to diffuse or transmit contained heat over a unit area per unit of time Rock with high thermal diffusivity more rapidly adjusts its temperature to that of the surroundings because it conducts heat quickly in comparison to its heat capacity or thermal bulk Because diffusivity is directly related to density thermal conductivity and specific heat by formula rock thermal diffusivity is required only if rock density has not been set If this value is changed the user will be prompted to allow Ventsim to auto calculate the rock density Rock Thermal The default Rock Thermal Conductivity This value is applied to an airway if it has not Conductivity already been set in the Edit Box Rock Thermal Conductivity is a property which describes the ability of rock to transmit heat through its mass Surface Wetbulb Drybulb The Default Surface Temperature
380. sible flows are used this is standard behaviour with Ventsim Visual Standard and optional with Ventsim Visual Advanced All airways resistance friction factors and fan curves will be automatically adjusted to this air density There is no requirement to individually adjust fan curves manually any fan curves simulated will be adjusted from the fan database defined curve density and will show the adjusted curve in the Edit gt Fan form Ventsim assumes a standard density of 1 2 kg m3 for predefined friction factors and resistances Unless specified otherwise these factors are adjusted to the density specified in this option Note that if Compressible Flows are used the model air densities will be different through the model Compressible airflow simulation ignores this value and uses the Surface Barometric pressure value as a basis to calculate air densities Setting this value with Compressible Flow set to ON will automatically set the surface barometric pressure based on the entered value and the wet and dry bulb surface temperature settings below The air density of the airways through the model is based on the barometric and fan pressure at each location and the calculated heat temperatures The calendar year at which the simulation takes place Ventsim Visual uses this value to calculate the age of an airway underground if the individual airway age is entered as a calendar year such as 2005 in the EDIT box W
381. sidered in the early stages of ventilation design Ventsim has three 3 different options for financial optimisation This method is based on variable airways size costs based on fixed and variable parameters and formulas While this method considers an infinite number of different sizes the formula assumptions used must be estimated from actual mining costs and therefore will vary between different sizes This method is based on defined airway costs and parameters for a number of discrete sizes and will construct graphs showing different size options Ventsim Visual User Manual Page 234 26 1 1 Option 3 Global This method is based on the Quick Select method but considers every single airway in the Optimisation mine model for optimisation Optimisation is only considered for larger than original size Graph Select Financial Optimiser airways as recommending smaller sizes often ignores the reality that mining sizes are designed for minimum sized passage of men or equipment A list of potential airways that can be optimised will be provided at the end of the simulation Option 2 The selected airways method allows for the definition of size and costs of up to ten different airways sizes and shapes These are defined in a table which is then used to calculate various ventilation costs for each size After calculation of each size a graph is drawn showing the three major ventilation costs mining power and fan purchase The l
382. sistance converted to an equivalent weight Pressure Totalloss The total pressure loss along and airway between entry and exit Pressure loss may consist of airway friction pressure losses due to wall friction factors and additional resistances placed in the airway Pressure Relative The relative pressure differential between underground airway and the surface standardised to the surface elevation A relative pressure differential of zero would result Ventsim Visual User Manual Page 258 Pressure Absolute Pressure Barometric Pressure FrictionLoss Natural Ventilation 29 1 4 Airway Attributes Resistance Resistance Wall Shock Friction Factor kfactor Dimensions Perimeter Area Length in no flow from a connecting airway to the surface A negative relative pressure would see air flow from the surface to the underground airway if a path was present A positve relative pressure would see air flow from underground to the surface if a path was present The pressure reported in atmospheric units of an underground airway corrected to surface elevation The correction removes the effect of elevation on pressure and permits a relative assessment between airways at different elevations The true pressure reported in total atmospheric units including the elevation effects on total pressure Barometric pressure increases with depth where no other pressure influences are present The loss of pressure along an airway
383. some other airway restriction Yellow normal operating resistance setting with a preset value Green a custom resistance value entered specifically for that airway Red a preset resistance operating on a reversal resistance value which has been activated by a reversing airflow and a restrict reversal option specified for the airway in the EDIT form pan iS Fixed airflow placed in airway Animated Ventsim Visual User Manual Page 265 30 2 5 Fixed Pressure 30 2 6 Contaminant Report 30 2 7 Fresh Air Report 30 2 8 Contaminant 30 2 9 Gas Green once simulated green indicates the fixed airflow is acting as a positive pressure i e it is contributing towards overall pressure in the mine model Red once simulated red indicates the fixed airflow is retarding normal airflow and reducing pressure i e it is acting as a resistance and contributing to overall pressure loss in the model Animated Fixed pressure source placed in the airway Green green indicates the fixed pressure is acting as a positive pressure i e it is contributing towards overall pressure and flow in the mine model Red red indicates the fixed pressure is negative and retarding normal airflow i e it is acting as a resistance and contributing to overall pressure loss in the model Indicates a contaminant report has been placed within the airway A Contaminant Find simulation will use this report to indicate pathways
384. sssssccesssseccccccccccssssssccessscccccccscccssssssceeess 16 VENTSIM VISUAL AN INTRODUCTION rvs ccssneasccscecssecvacesiussicesixeccuesdessessedussenssivaeeuasdkssches tues cuescusaenandasasnavdervevevinseduans 17 2 1 ABOUT EIERE EE 17 2 2 COMPUTER HARDWARE REQUIREMENTS 19 VENTSINMVCLASSIC TO VISUAE GUIDE lt a A 20 3 1 SEI dE 20 3 2 ANIMA Nao dolo cado 21 3 3 ELEVATION DATABASE LEVELS Jossie dada dci aid 21 3 4 EN O TOR TIS AP eT TR TS ee PT NTS RE oe A ere PT TS PP oe TN er PT Sr TOS a 21 3 5 Dn EE 21 3 5 1 Colour and Data Mongger EE 21 3 6 COORDINATES Sra dd dada dida 22 3 7 EDTINGAND INFORMATION paritaria dada da ii 22 3 7 1 EE 22 3 7 2 ere 22 3 7 3 e elei AE e EE 22 3 8 A tege tegEEEeR 22 3 9 A O O peuciduas acetal ves 23 AAA O A 24 4 1 POINTOF FOCUS E 25 4 1 1 M vmgthe pont OF Tocs aaa ANA A O 25 4 2 IVIGILTIPRE WINDOWS AAA AAA AAA AAA AAA AAA ARALAR AAA A 26 4 2 1 DOCKED WINDOWS usar SARA AOS AAA IO 26 4 2 2 Undocked WING OWS sI 26 4 2 3 The Active Mee Wai 26 4 2 4 Drawing between windows 26 4 3 USER CONTROL SUMMAR o o I Se raced Sta dg 27 4 4 VAR EDIT PLANE NAS ANA AAA AA AAA AAA 28 4 5 DRAWINGIN THE THIRD DIMENSION cis ai 29 4 5 1 TRCATUC Vertical CU ia 29 4 5 2 DGG ee 29 4 5 3 Manual Coordinate ENY EAS USA E AA A ea ee a 30 4 5 4 MONG e ET 31 4 5 1 MOVING Copying CON es edo 32 4 5 1 CODVING Ee OY EN 33 THE MENU BAR os 34 5 1 FLE MENU aaraa a E E A 34 51 21 E e EE 34 5 1 2 ODE
385. st of the airway not the power cost of distributing air through the model Selected Lifetime Cost Total cost of mining and ventilating selected airways for the life of the airways Model Annual Vent Cost Cost of ventilating the whole of model for one year Model Fan Cost Combined cost of all fan purchase costs based on the required ventilation power for the entire model Model Lifetime Cost Combined cost of mining selected airway plus cost of ventilating whole of model for life of the airways Sel Airflow avg Average airflow through each selected airway Net Airflow total Airflow through entire mine model In most cases only the Selected Airway costs and graphs will be relevant to the simulation results however at times it is important to consider the effect of changing airway sizes on the rest of a mine For example creating a large shaft to deliver more airflow to a mine may simply increase the cost of the airflow through other parts of the mine offsetting some of the expected ventilation savings For this reason Total Model ventilation costs are included as a separate column and graph and should be considered if the project is an addition to a mature mine Assists in choosing the most economical airway sizes for the ventilation required This function can help optimise the size of vertical or horizontal airways by considering a variable cost of mining based on airways size and then optimising airflow power costs th
386. suggested a factor of 50 can be applied to convert total particulates to an Elemental Carbon EC level or 80 to convert to a Total Carbon TC level Finally the diesel engine emission outputs may in some cases be further reduced by the equipment manufacturer or mine utilising catalytic regenerative converters and particulate filters This can further lower the emission rate further by 50 or more and if present should be considered in the final DP emission value Conversely worn or damaged equipment may produce significantly higher than expected emissions Where possible mine sites should measure actual equipment exhaust to obtain actual values however if this is not possible then equipment manufacturer advice should be gained or a conservative approach from EPA data taken Simulated atmospheric concentrations of particulates are only the first step in what must be a multi pronged approach to controlling exposure levels Operators of machines may be directly exposed to higher concentrations than predicted due to their proximity to exhaust emissions Conversely operators protected by filtered cabins may be exposed to lower concentrations that predicted Also keep in mind that mine concentrations of DPM which are higher than the allowed standards still may be permissible if other control methods such as reduced exposure time or personnel protective equipment are used to control exposure Where control of exposure measures cannot be guar
387. sulting estimates from the assistant may not always equal the values ultimately calculated in the simulator The assistant contains five 5 tabs Calculates the required heat loads to condition air from one state to another The values are returned as sensible and latent heat estimates Heat Assistant D a ca Air 1 Air 2 Diesel Eng Diesel Fuel Water Chil INLET OUTLET WB Temp 213 24 DB Temp 278 35 Pressure kPa 115 0 114 8 Air flow m3 s 16 0 Estimated Heating Cooling Sensible Heat 153 7 kW Latent Heat 33 6kW Calculate Cancel Figure 13 1 Airflow Calculator 1 Values returned for sensible heat are generally ve for heating or ve for cooling Values returned for latent heat are generally ve for humidification or ve for de humidification or drying of air The word generally has been included as differences in pressure can influence the amount of sensible and latent heat available in the process Ventsim Visual User Manual Page 147 Heat Assistant erg Seml Air 81 Air 2 Diesel Eng Diesel Fuel Water Chill INLET OUTLET WB Temp c 213 DB Temp 278 Pressure kPa 115 0 Air flow os is 16 0 Estimated Heating Cooling Sensible Heat 184 8 kW Water 14ml sec Accept Cancel Figure 13 2 Airflow Calculator 2 Similar to the Airflow 1 calculator this calculates the required heat loads to condition air from one st
388. t length Because the loss is standardised to a unit length this value is independent of the actual length of the airway The electrical input power into a model to generate pressure and airflow The power input includes efficiency losses due to fan blade efficiency but does not include motor efficiency losses The theoretical cost of the power loss due to friction converted to an annual electrical cost based on the power cost set in the Settings The theoretical cost of the power loss per unit length due to friction converted to an annual electrical cost based on the power cost set in the Settings Because the loss is standardised to a unit length this value is independent of the actual length of the airway The electrical input power by a fan or theorectical fix flow into a model to generate pressure and airflow The electical input includes both fan or fix efficiency factors and an electrical motor efficiency factors specified in the Settings Psycrometric properties of air decribing the temperature a volume of air would have if cooled adiabatically to saturation at constant pressure by evaporation of water into it Psycrometric property of air describing the temperature of air measured by a thermometer freely exposed to the air but shielded from radiation and moisture An older index of heat stress still commonly used Ventsim Visual uses Basic Effective Temperature Wet or Dry bulb temperatures below 20 degrees celcius or above 36
389. t 25 frames per second The number of frames recorded depending on the Dynamic Screen Update frequency in the Simulation Dynamic settings For example if a dynamic screen update frequency of 10 was chosen and a dynamic increment of 1 second was used then the video would be recorded at 1 frame per 10 seconds and would play back at 25 x 10 250X real time speeds 23 8 Interpreting Results Simulations can generate large amounts of data While in many cases temperature and gas may build up as expected and the simulation will show the extent and concentration of heat and gases through the mine as different times sometimes a large fire can generate significant disturbance to primary airflow particularly on sloping airways such as declines and shafts Rates of airflow can also impact on temperature and gas build up within air passing the fire A fire will expand the volume of air due to heat addition and the expanded gas and resultant increased downstream airflow can cause additional frictional pressure loss downstream from the fire This can slow the airflow past the fire causing a choking effect which can then compound the heat and gas build up further reducing airflow DP PP GP PPP EF PP PF PP EF EP EP EF EP S d e d AE AE o LS A VC E EC d d d E s d S vw ais d t d Pe Y d d Es e d d d dE d d d Ss d d d Time Second Figure 23 1 Chart showing a complex buildup of Carbon
390. t change for subsequent simulation and can be used for example to compare the graph results between two different simulations Ventsim Visual User Manual Page 216 23 7 4 Exporting simulation data To export this data to a spreadsheet or other document use the CLIPBOARD icon on the graph for to copy the data to the Windows Clipboard Then for example open an Excel Spreadsheet and PASTE the data into the spreadsheet All available data for that location will be copied into the Excel spreadsheet cells 23 7 1 Smoothing Data Data results can be filtered to smooth and average rapid changes If the Log Frequency of 23 7 1 Video Recording 23 8 1 Overview 23 8 2 Airflow reversal data is greater than 1 then Ventsim will automatically smooth the data during simulation by averaging the data collected during every dynamic increment period Data results can also be smooth after simulation by selecting the Smooth Data option in the VentFIRE menu The smoothing factor entered collates and averages the defined number of data events around each data point This function can also occur automatically after simulation if require by setting the option in the Simulation gt Dynamic settings VentFIRE simulation can take a long time particularly for large models The Video Recording option will record a video of the VentFIRE simulation progress over time to play back at a future date The speed of video recording will play back a
391. t in order to maintain the same view distance as the previous point of focus Ventsim Visual User Manual Page 25 4 2 1 4 2 2 4 2 3 4 2 4 Docked Windows Undocked Windows The Active Window Drawing between windows e The Elevation of the point of focus can also be changed by selecting the Shift key while using the Mouse Scro button A transparent grid if the grid is turned on will show the horizontal plane of the point of focus 4 2 Multiple Windows Ventsim 3 0 can display multiple graphics windows up to 7 each with its own independent view of the ventilation model Every window is fully 3D and is customisable in terms of data display including colours levels layers text and graphical items shown F And Ventsim Visual II Beta coalmine vsm Example Coal Mine Press X to hide surfaces Lol Lo l File Edit View Savedviews Run Connect Tools Settings Window Help PRONG SOC Bo ENG B2 Akt HOURS 99 060 O d OS Y Test 13110 Test Te za Arow Velocity y mvs com T Lager sl Lag Blairtiow Velocity D m s T Laien Quantity D m s ZS Kl A an Cal bel fr D E As SH e lt gt E ge Bagage evi Test za ED aimiow ed Ke Ms ro KZ WW EECH E n CSTR 1 AJOS leede 1692 0 3042 6N 32402 Alrsimulation successful Compressible No NVP No airways 3105 By default Ventsim will tile the first four 4 windows within t
392. t of 0 0 Airway profiles are intended to extend from 1 1 to 1 1 which represents the full extent of the profile The actual airway size of the profile is set in the EDIT box which then scales the profile to whatever size is specified The profile shape is updated in the lower right corner once the profile string is entered and re selected To enter or add a profile click on the Profile String cell on the profile grid A data enter form will show allowing points to be entered or modified For example a square would have an X Y profile 1 1 1 1 1 1 1 1 which represents the X Y extents of all four corners around a centre point of 0 0 If this profile is chosen in the EDIT box when setting an airway entering a width and height dimension of 5 0m would scale the profile accordingly Note that there is no need to provide an area or perimeter Ventsim automatically calculates the perimeter and area based on the profile shape given Ventsim Visual User Manual Page 120 11 2 9 Wetness Fraction Defines the wetness fraction options for underground airway wall wetness Wetness 11 2 10 Sensors 11 2 11 Combustion 11 2 12 Leakage 11 2 1 Gases fractions can be applied to airways in the HEAT section of the EDIT box In general wetness fractions closer to zero represent dryer airways and fractions closer to one 1 represent wet airways Lists the current sensors imported from the LiveVIEW option A selection of
393. t of time into the airstream The amount of time is set in the EDIT box FIXED release emits the same contaminant level throughout the release time Linear Decay releases a decreasing amount throughout the release time starting at the original set contaminant levels and reducing to zero at a linear rate by the end of the release time Logarithmic Decay is similar to linear decay but more rapidly reduces concentration at the start of release time according to a logarithmic power scale Time release dynamic contaminants are intended to be used for sudden or limited time release events such as a stench gas release gas burst or inundation or tracer gas release or limited emission of smoke or other contaminants from a source The simulation is useful for not only detecting the spread concentration range and timing of contaminants but also for establishing how long it will take to clear contaminated areas of contaminants 18 4 Dynamic Explosive Contamination Ventsim 2 utilised a throwback blasting volume method to calculate an initial volume of blast contaminated air that was fed into the mine atmosphere at a decaying rate This method was restrictive in that the throwback volume factor and the initial throwback volume contaminant concentration must be estimated for each blast Ventsim Visual User Manual Page 180 Dispersion Rate Actual blasting tends to produce more concentrated initial contaminant volumes for large blasts compared to smal
394. t the sides of the screen can be turned off or on as required Use this function to select the visibility of each toolbar Reconnects the Windows operating system to the graphics hardware device The software link may occasionally become disconnected or corrupted resulting in a blank display Reconnect the DirectX interface will reset the graphics software to hardware link and re establish the display Ventsim Visual User Manual Page 117 11 1 1 Preset Values 11 1 2 Sort Order 11 PRESETS 11 1 Preset Values a Ventsim Visual Preset Value Edit Reversing Resistance en leave zero for default Linear 100 Ne zm Ir Bulkhead 1000000 0 Blocked Drawpoint 25 FabricSeal 25 HangHlaps 1 5 Mesh Brattice 4 Full Pass 1000 Lo Stockpile 0 1 Stockpile 1 HiStockpile 10 WoodDoor 5 0 0 0 0 0 0 0 0 0 No eG 2 2 2 a y Figure 11 1 Preset Table Options Preset values provide a quick and convenient way to specify airway characteristics and parameters that may be commonly used in the ventilation model Examples are resistances such as doors or seals common wall friction factors shocks losses heat sources The preset table also provides access to model primary and secondary layer names and colours as well as air types tunnel profiles fans wetness fractions and numerous other items used in Ventsim simulation Any preset value which is changed will be applied to A
395. t which Ventsim Visual will flag a warning if water suspension checking is optioned Warnings do not affect simulation but simply alert users to potential problem areas Water suspension is unlikely to be a problem in shorter shafts This setting allows the simulation to ignore shafts that are less than a defined length The flow at which Ventsim Visual assumes zero flow This function does not directly affect simulation and is simply used to determine whether airways are displayed when the zero flow graphical option is used to hide airways with no flow Ventsim Visual User Manual Page 134 12 4 2 Contaminants The default contaminant values and factors to use in simulation In most cases these values can be overridden in the Edit gt Contaminant box Cp Contamination Unit CO ppm Defaut Contamination Value 2000 CO ppm Diesel Particle Emmisions 0 100 q KW hr Dynamic Contaminant Threshold 1 Contaminant Contaminant Figure 12 4 Simulation Contaminant Settings Contamination Unit An arbitrary unit defining the volume concentration value of the contaminant simulation Ventsim defaults to a unit less value which normally represents a percentage however any volumetric portion unit such as ppm or mg m3 could be used Results of the simulation shown will be representative of the original value entered in the contamination value field Default Contamination The default amount of contamination to place in an airway if
396. t which rotation is damped can be adjusted or turned off using these settings HINT To allow the model to rotate freely without stopping choose a damping level of zero 0 or HOLD THE CTRL key down when rotating a model with the mouse Hide or shows arrow node and text data by default This can be used to improve display clarity by removing unnecessary graphical details Note that this function can be overridden from the View menu options or the RIGHT click context menu options for text and other graphical items The rate at which to update the screen graphics To conserve laptop battery power the minimum frame rate option is available to reduce power when Ventsim Visual is not the active program in Windows Scales airways graphically so they appear larger or smaller than the specified dimensions This does not change the calculated airway size A factor of 1 is normal scale Factors larger than one will enlarge airway graphics while factors smaller than 1 will shrink airway graphics This function may make very large extensive models larger and easier to see or conversely can make very small model eg lab scale apparatus also easier to see Size of airway text displayed on model Larger text sizes are generally clearer to read however excessive data may clutter display The size of the nodes icons and arrows Note that the size reduces in wireframe mode to improve display legibility The size of the nodes icons and ar
397. tem protects against unauthorised use of the Ventsim Visual license and informs other users who has currently activated the software license Once a license is activated on a computer it cannot be moved to another computer unless it is first released from the activated computer If another computer tries to activate the same license simultaneously this will be prevented and a warning will display the currently licensed computer and the login user name of the person who has installed it An internet connection is required to activate and release license certificates from a computer If an internet connection is not available or an internet connection is not Ventsim Visual User Manual Page 44 5 1 21 Licensing Problems Exit authorised by your firewall or company administrator try to arrange a link to the http ventsim com website If this cannot be done a manual license transfer can be performed via email located under the file menu In the event the license manager fails to activate or release the license note the error message and take the following action If the error message reports the license is active and in use by another computer then only that computer can release the license If this computer is no longer available and license has not been released then contact license ventsim com for further assistance If the error message reports an internet connection problem then click the TEST www ventsim com web connec
398. tem relies on the use of accurate mining costs to estimate the costs of different airway sizes and shapes The correct power cost must also be placed in the Settings Performs a financial simulation and maintains identical flow through each size to ensure the airway size is optimised for the required flow Note that once a size is selected in the final model then unless a fixed flow has been chosen adjustment to fans or flow elsewhere in the model may be required to achieve the desired flow through the new shaft size This is the method that should be generally chosen when optimising shaft sizes for new or extended mines Performs a financial simulation and allows the simulation to adjust the flow through the airway unless using fixed airflow based on the resistance of each size This option should only be used if it is understood that by allowing the airflow to adjust the basic economics of the shaft also adjusts and may place additional costs elsewhere in the ventilation model The function is useful to establish shaft or airway size performance where existing fans or infrastructure is in place but should not be used when designing a new mine or shaft and fan system where an optimised size is required for a specific airflow Using FAN curves on selected airways will result in decreasing flow for smaller airways which in turn despite increasing fan pressures may actually result in a decrease in ventilation costs There is no point in estab
399. ter or change the values in the Preset Spreadsheet Preset values can be added or changed by clicking the Shock button next to the value box If Automatic is chosen Ventsim Visual will attempt to recalculate a new value during simulation by observing airflow direction airway geometries and airway size changes Ventsim will only calculate the Automatic Shock Value once to prevent oscillations in simulation results If the model geometry or air direction changes it is recommended to RESET the shock value to zero 0 and let the AUTO shock loss recalculate the value during the next simulation Note that this is a rough estimation only and may change slightly with every simulation due to changing airflow and directions It assumes sharp corners on all direction changes and size changes and is therefore considered to be a worst case value DO NOT use AUTO shock losses everywhere through a model AUTO shock loss should only be used on known areas of high airflow and sharp direction change or size change Using SHOCK loss throughout a model will over predict total model pressure requirements by up to 20 because every corner and bend will be considered as a worst case geometry This is not the case for most mines as corners and bends are often smoothed or rounded In critical areas which are subject to high airflows and large shock losses a more thorough examination of airways should be performed and the shock factor settings manually
400. the LiveView type If there is no equivalent column this item can be ignored for now Single Sensor value per row If the data contains a single sensor data value per row in addition to other sensor attributes such as time sensor type etc then choose the Single Sensor Value per Row option This will allow other attributes in the row to define different characteristics of the sensor Multiple Sensor values per row 24 2 4 Testing the Sensor Data Import In this case each record entry in the data source may have multiple sensor values per row Select the Multiple Sensor Values per Row option For example a single recording sensor station may list multiple gas sensor values eg O2 CO2 CO H2S etc on the same row The columns containing the data values will then be split by LiveView on the sensor import and individual sensor types can then be defined after importing the values in the same way as single row data Note that in this case other sensor attributes such as sensor types cannot be defined in the data source tables and must be manually assigned after importing the data To TEST the mapped connection to see what sensor information will be imported click the SENSORS button a Sensor Data Input 29 Dec 2011 13 22 36 SensorlD Value TimeStamp gt 4 881278 28 Dec 2011 21 04 36 SAFV2 2 974703 28 Dec 2011 21 04 36 SCH41 2 1278 28 Dec 2011 21 04 36 SCH42 0 5843696 28 Dec 2011 21 04 36 SC 39 64058 28 Dec 2011 21 0
401. there are more than say 500 airways this may take a minute or two to simulate Therefore the option will be given to abandon the simulation or simply show the airway which recirculate without actual amounts On faster computers it may be desirable to life this limit to prevent Ventsim pausing and asking permission The volume of air that is allowed to recirculate before the Check Recirculation routine flags a warning and initiates a full recirculation check 12 5 Ventsim System Settings Ventsim Program settings control over arching settings which influence all parts of the program Ventsim Visual User Manual Page 145 Language English Maximum Arway Mumbers 30000 Maximum Reference Elements 1500000 Unit Type Metric Use Mass Flow No System Settings Figure 12 7 Ventsim Visual General Settings Unit Tyve The type of units to use in Ventsim Visual The program operates natively in SI Metric with underlying calculations performed in metric units To display imperial values and accept imperial input set the unit type to Jmperia The imperial setting uses a conversion table to calculate the conversion from metric and can be customised to suit mine preferences The imperial conversion table can even be set to use a combination of Metric values by setting the program to IMPERIAL and then using the SETTINGS gt UNITS menu to individually specify what units will remain ALWAYS METRIC Warning the conversion table has set
402. timate of 1000 per kW would mean a fan of 30kW in size would cost 30 000 to purchase This figure is used in the optimisations to estimate fan costs for different fan power requirements This cost should be calculated to include the electrical infrastructure and installation costs as well as the fan purchase cost Mine Life The expected average mine life of airways in the mine This figure is used by the optimisation to estimate to power costs consumed over the life of an airway NPV Rate The discounted rate of future costs to determine the present value of expenditure on power over the life of the mine Values higher than zero 0 will decrease the significance of discount future cost savings placing more importance on initial capital costs such as the airway mining cost and the fan purchase cost Power Cost The cost of power supplied to the mine The power cost is used to calculate the ventilation cost of running a mine model and applied to all fans fixed quantities and fixed pressures The power cost is local currency unit dependent Total power costs for mine model will be displayed as a factor of this value HINT To gain the true operating cost of a ventilation model users should consider including a maintenance and depreciation component in the power cost to cover the future cost impact of maintenance repair and replacement of ventilation infrastructure A value of 15 20 additional cost is typically used Ventsim Visual Use
403. tion link on the License Manager form Ensure that Microsoft Internet Explorer can link to the Ventsim webpage If this does not work then the Windows connectivity problem needs to be resolved before further action can be taken in Ventsim Ensure an internet connection is available and the firewall or proxy server is not blocking the Ventsim website Some companies have PROXY settings that inhibit third party programs using the internet In most cases Ventsim Visual will automatically adopt the same proxy settings as Microsoft Internet Explorer If these settings are not available from the local computer they can be entered into Ventsim using the Proxy Settings section If the license is a DEMO or a STUDENT EDUCATION license and needs to be removed from the computer click on the FILE gt RESET LICENSE menu option in the license manager This command closes Ventsim Ventsim will prompt if your model file fan database or defaults have not been saved since last modified Ventsim Visual User Manual Page 45 5 2 1 5 2 2 5 2 3 5 2 4 Undo Redo Copy and Paste Airways Clone and Apply Attributes 5 2 EditMenu Reverses the previous action Undo is a fully functional undo facility that will undo a number of previous changes made to a model up to the buffer size of the undo function Note that while it will not directly undo a simulation by pressing UNDO until your previously model is in place and then re s
404. tion pause in milliseconds can be entered to slow simulation down For larger models it is suggested to keep this pause to zero 0 to prevent unnecessary simulation delays The time period for a simulation to complete in seconds For example 7200 is equivalent to running the dynamic simulation for two 2 hours At the end of the simulation time Ventsim will ask if the user wishes to continue the simulation Ventsim Visual User Manual Page 136 12 4 1 Simulation Environment ADVANCED Air Density Model Environment Current Year Geothermal Gradient The environment factors describe values used by physical items within the model They are critical to identify the base starting points of a ventilation simulation or providing default air or heat simulation parameters to airways that do not have specific values set El Environment Air Density Network Environment 1 20 kg m3 Airway Age 5 00 year Current Year 2010 63 Geothermal Gradient 2 5 C M00m Rock Density optional if diffusivity set 2 200 kg m3 Rock Specific Heat 790 0 Jikgt Rock Thermal Conductivity 2 00 Wim Rock Thermal Diffusteity 0 938 mAs 10 6 Rock Wetness Fraction 0 15 Surface Elevation of MineGrid 600 0 m Surface Pressure Barometric 101 0 kPa Surface RockTemp 0 0 C surface Temp Adjust Yes surface Temp Wet Bulb 240C surface Temperature Dry Bulb 24 0 C Figure 12 5 Simulation Environment Settings Defines the default air density to use in the model if incompres
405. tions Surface Close End Group The height of the airway For vertical airways the width and height are interchangeable For Arched or Shanty airways the height is assumed to be at the centre of an airway The calculated area of the airway derived from the width height and shape If the shape chosen is irregular then the Area box can be edited otherwise it will remain as Read Only and display the calculated size based on the width height and shape Assumes a continuous area obstruction along the airway for example a duct services or compartment and removes this value from the available area of the airway Note that this should not generally be used for short fixed objects such as a vehicle in this case the orifice function may provide a better simulation result Assumes a continuous obstruction of backfill along the length of the airway and removes this value from the available area of the airway In addition it removes the area of covered airway that transmits heat into the airway to represent the insulating effects in heat transfer calculations for backfilled stopes The calculated length of the airway The calculated length is automatically derived from the airway coordinates To change the length click on the Check Box and type in the new length This may be required if the model is drawn as schematic if an airway is moved to allow easier viewing but the true original airway length still needs to
406. tions for airflow fan and fix inputs Shows heat related data such a temperatures internal heat content humidity Show airway specific indentifying traits such as index or unique numbers and primary and secondary layers numbers Shows airway contaminant factors source values simulated values spread times and diesel particulate levels Show airway rock conditions such as wetness fractions specific heat and other rock parameters Not currently used Ventsim Visual User Manual Page 86 8 1 3 8 1 4 Displays screen data related to the Data Category specified in the left hand pull down menu Each data category will have a unique selection of data types that are made available when the category is changed Warning some data types such a pressures may not be correctly set until after a successfully simulation While Ventsim Visual saves previous simulated values in a file these values may not be valid if further changes and modifications have been made to the model Another simulation may be Dynamic Text Size Dynamically rescale the text on the screen so that it can be easily adjusted for clarity or Favourites presentation The button will toggle between zoom scaled text which grows larger or smaller the closer to the object graphics or constant size text which remains the same size regardless of zoom level Shows the Favourites Manager Favourites are names for groups of data that can be simultaneously displa
407. tise for long lengths of rigid duct then additional fans can simply be installed at locations along the duct by using the previous method to install fans or fixed flows If the duct is built with leakage leakage can travel too or from the duct either way depending on fan and suction pressures HINT Using the TOTAL RELATIVE PRESSURE colours the user can determine if the duct section are under pressure or suction S Vertzen Visual H Beta Dlue_sky vim Example Metal Mine with Problems gt gt e IR e cad oS ES File Edit View Sevedviews Run Conmect Tools Settings Window Help SEH ap am EEG aoon AA p k Id AS p gt ED Pressure v Pressure Total A Pa T Aino jritisi Development e m s Display 5 ax Bg 22539 La H 3 re a v D D AOO Coords 1225 1 2015 5N 1067 Air simulation successtul Compressible Yes NVP Yes auways 374 Figure 16 3 Colours showing the relative internal pressure ofthe duct Multiple Ducts If more than one duct is to be built along an airway then the OFFSET function can be used to ensure the ducts are separated and will simulate correctly For example if two ducts are required the first duct can be built with a HORIZONTAL offset of 2 and the second duct can then be built with a horizontal offset of A This ensures that either duct sits on opposite side of the airway and that they can be independently simulated Ventsim Visual User Manual Page 172
408. to 33 7 C 54 0 C Sigma Heat 90 2 kJ kg to 108 9 kJ kg Heat addition 4 463 6 W m sensible 2 555 0 W m latent Heat addition total 446 3 KW sensible 255 5 kW latent Manual addition 714 3 KW Contained Energy 3 402 6 KW to 4 104 8 kW Relative Humidity 39 7 to 25 2 Condensate 0 misec Simulated Data Elevation 126 1 m Wet Bulb 29 9 C Dry Bulb 425 C RH Moisture 0 0194 kg kg 39 7 0 0222 kg kg 482 c 446 3 kJ s WRT Calculated 47 3 Sensible Heat 7018 kw Latent Heat 255 5 kJis Copy to Clipboard Air Simulation O APPLY oe Cancel Figure 9 13 Heat Data Wet bulb and dry bulb temperatures at the start and end of the airway Page 112 9 7 4 Heat Addition Heat additions total Manual addition Contained energy Relative Humidity Condensate Simulated Data Elevation Wet Bulb Dry Bulb RH Moisture VAT Sensible Heat Addition Latent Heat Addition The Sigma Heat content of the air at the start and end of the airway This value describes the heat content of air per unit weight and is therefore independent of air or mass flow rates The amount of sensible and latent heat added to the airflow per unit length The heat may be sourced from rock strata auto compression or a heat or refrigeration input value The total amount of sensible and latent heat added for the full airway length The amount of heat added by the user in the form
409. to Ventsim Do not convert the centrelines to airways at this stage The imported model will show as a collection of line strings Select the Tool button DRAW gt CONVERT CENTRELINES Draw a fence around the centreline strings in this case all the strings to convert to standard size airways G lle D gt POG Draw Single Draw Continuous Draw Coordinates Vent Duct Measure OJEjO S Ofunits m3 s Coords 6096 3 E 13336 1N 8157 Convert Any Convert DX Ventsim Visual User Manual Page 252 Figure 27 18 Resulting conversion with colour levels reset Many airways will have complex curves or may not connect properly To tidy up the import we need to Simplify and Bind the new airways Use the TOOLS gt FILTER function to activate this option Click on SIMPLIFY This will remove unnecessary detail allowing for a simplified and easier to work model Click on BIND increasing the bind search distance to 8m to ensure broken airways are joined together Press the BIND button several times to ensure all optimisation have been found Saved views Run Window Help DOS get Fo DHOLI evels Spreadsheet Utilities way Reduce airway number by combining adjacent airway into a singl Troubleshooting gt Reset Network Preset Values Unit Conversions Quick Settings gt Settings Eo Fitter All Airways le Ela x All Tools Binding Duplicates Convert
410. to return to the top of the page when a new function is selected Scale view window so all model graphics fit on the screen Fit All Home Saved Views Increases the distance away from the point of focus by a factor of two Flight Enters a flight mode which allows the user to freely fly around the model in three dimensions To control the select Level Pg Up Dn flight system simply move the mouse similar to an Show All aircraft flight stick using the scroll wheel to move forwards and backwards Clone Attributes Ctl C Mouse Controls Apply Attributes Ctl V Pitch down RE S Add D Pitch up Edit Yaw turn left or right select 5 Delete Del Control Speed Forward and Reverse Copy C Exit flight mode Mowe Mi Selects one or more levels or elevations for separate SE lt display on screen This can isolate a specific elevation Reverse R range of airways for display which can clarify display on screen in complex models The function works Action Toolbar independently of the levels specified in the level Data Toolbar elevation database Any elevation or range of elevations can be selected at any time View Toolbar The elevation range is selected by LEFT mouse clicking Reset Display one or more airways on the screen and RIGHT mouse clicking to commit and activate the selection As airways are clicked the elevation range selected will turn YELLOW To select a larger area or range of elevations draw a fence b
411. ton S File Edit View SavedViews Run Tools Window Help 14434909 Jugen Jomiy PA QGOOOORRGOe DO 0 0 Airway 1 Waming no entry airway or surface connect a Airway 2 Waming no entry airway or surface connect Airway 3 Waming no entry airway or surface connect Airway 9 Waming no exit airway or surface connectic Airway 201 Waming no entry airway or surface conn d Airway 217 Waming no exit airway or surface connec Airway 218 Waming no entry airway or surface conn Airway 223 Waming no exit airway or surface connec 230 Waming no entry airway or surface conne Airway 232 Waming no exit airway or surface connec A Units m3 s Coords 7614 6E 2515 9N 9745Z Figure 15 7 Example of import error after simulation resulting from misaligned ends or unjoined nodes In most mines a number of blind or dead end headings will exist By model definition a blind heading cannot carry airflow as it does not have a continuous path of airways leading Ventsim Visual User Manual Page 166 15 5 2 Ventilation Ducting and Blind by auxiliary ventilation duct and often need to be simulated within a model Auxiliary fans 15 5 3 Headings Interconnecting Mine Airways to and from each end In many real cases however these headings are effectively ventilated blowing into ventilation duct are moving air from one part of the mine to another and often much of the heat and moistur
412. ts however if maximum accuracy is critical and the range of assumptions entered into Ventsim is accurate then the high slow simulation accuracy setting is recommended An extensive list of settings used by Ventsim Visual that control the behaviour simulation parameters and visual appearance of the program Settings are divided into a number of categories including Ventsim Visual User Manual Page 68 Costing Parameters for ventilation and mining costs required for accurate optimisation of airways and sizes Basic program settings to establish default airway sizes factors and file settings Settings that control the display of Ventsim graphics and text on the screen A wide range of factors and settings controlling the performance of different simulation methods in Ventsim Technical settings controlling the memory requirements in Ventsim language and the type of units used eg Metric or Imperial General Airway defaults file settings and behaviour and license proxy information Graphics Options to modify displayed graphics including icons text sizes and more Simulation Settings to control simulation parameters and behaviours System Settings Settings to control computer reserved memory language and type of units for simulation data For further information on settings go to the settings sections 5 9 Windows Menu 5 9 1 Fit All Fits all display data on the screen 5 9 2 New Window Adds a new window form to t
413. ttings Window Help 1 File Edit Vi a O KE enu ar _ ar eo 9 AEN Morey EJ EEE Action Tool Bar Data Tool Bar ee ERES ng S YM d gan e tot A gd aren dr Y gt SW p aj o A KEE 0 View Tool Bar YESA j NE na Teo Ta D he m T D Oia ET H 3D Viewer Ee R na D a Ra 4 my as ms lt lt 28 0 6 Ollcoords 294 6 2159 6N 17Z Status Compressible Yes NVP Yes SS SS airways 527 D Status Bar gei rta Figure 4 1 Ventsim Visual Main Window 1 Main Menu Consists of options required to load save view and manipulate the model as well as options to change settings and simulate ventilation models 2 Action Toolbar Consists of many of the construction tools required to build ventilation models In addition it contains a number of buttons for different types of ventilation simulations as well as options to save or load new model change stages and alter animation speeds for arrows This toolbar can be hidden but not moved to other locations 3 Data Toolbar Allows the text or colours of airways to be changed Displays or hides the colour legend control This toolbar can be hidden or moved to the upper or lower part of the screen Ventsim Visual User Manual Page 24 4 1 1 Moving the point of focus 4 View Toolbar Contains options to show or hide various graphics items such as arrows text nodes and reference DXF graph
414. tute for an accurate fan manufactures curve if available Estimate Fan Curve Quickly estimates 10 evenly spaced points of fan curve duty from as few as 3 entered points The estimation method will use the Cubic Spline method to add the additional points This method should only be used if additional fan curve data is not accurately available Ventsim Visual User Manual Page 157 15 2 1 Model Types Closed Model 15 BUILDING A VENTILATION MODEL A ventilation model must have a number of key components to successfully run Some Simple Rules for Constructing a Model are e All airways in a model must be connected at both ends to another airway unless connected to the surface or blanked off as a closed end e A model must have a device s to produce pressure within the model and induce airflow Pressure producing methods use in Ventsim Visual includes placing fans or a fixed airflow or pressure within an airway e Any fixed flow in an airway must not restrict another fixed flow elsewhere in a model or be overly restricted by an impassable high resistance Errors contributing to the above conditions account for around 90 of simulation errors and problerns noted in Ventsim from Chasm Consulting observations 15 1 Overview There are many different ways to build a computer ventilation model Ventsim Visual as the name suggests utilises a visual approach to creating models and the fundamental structure shape of mo
415. uct of air mass flow and Sigma Heat along an airway The value is useful to determine the amount of heat an airflow has gathered or lost along an airway Relative Humidity Relative humidity describes the amount of water vapour that exists in a gaseous mixture of air and water It is defined as the ratio of the partial pressure of water vapour in the mixture to the saturated vapour pressure of water at a prescribed temperature Relative humidity is normally expressed as a percentage Moisture Content The unit mass of moisture per unit mass of dry air Condensate The volume flow rate of moisture condensed from an airflow normally due to refrigeration or pressure drop up a shaft Heat Added L Sensible plus Latent heat from all airway heat sources per unit length Sensible HeavL Sensible heat from all airway heat sources per unit length Latent HeavL Latent heat from all airway heat sources per unit length Sensible Heat Sensible heat from all airway heat sources Latent Heat Latent heat from all airway heat sources External Heat Heat added or removed by the user excluding strata heat input 29 1 7 Descriptors Ventsim Visual User Manual Page 261 away Mame Airway Name Node Name Entry Number Index Number Unique Primary Name Secondary Name Friction Factor Shock Factor Airway Type Profile Air Type Airway Number The internal array number of an airway reference by Ventsim Visual Ventsim Visual will report this numbe
416. ues or fans When a Ventsim file is linked to a Master File and the file is saved the settings are also saved to the Master File and will be available to all other Ventsim Visual files which have a link to the Master File The settings in linked Ventsim Visual files are updated from the Master File when loaded If the Master File is not available then a warning will show and the most previously saved settings will the used Warning Using linked Master Files can be dangerous if settings made in one file adversely affect another linked file For example if a fan is removed or replaced with another fan and the file saved then all other linked Ventsim Visual files which used to use this fan may no longer work correctly If a linked Master File is used it is normally better to add new settings not remove or delete existing settings which may be used by other files Ventsim Visual User Manual Page 35 9 1 7 Defaults Create New Creates a new Master file template which can Template Aber Ses then be linked to other Ventsim Visual files When creating Y the file it is automatically linked to the current file Other Select Items to build into template Ventsim Visual files can be linked to this same Master File J by opening the files and using the Link option below Hint When creating a new file there is an option to specify what common settings you would like to make in the master file For exampl
417. ur range derived from the top data range and the range limit sliders Ventsim Visual Unfidyeg dalisplayed data type OPTIONS Right Click Mouse Button Reverse Spectrum Reverses the colour range direction Restore Colours Restores the colours to the default Ventsim Visual palette Auto Range Restores the range to the full spectrum of available airway data values Hint The Display Manager will initially default to automatically range and set colours for the displayed data If the range values are manually adjusted or the colours are changed the Display Manager will no longer automatically range and adjust colours for the data displayed To restore or recalculate the range and colours simply click the Auto Range or Restore Colours buttons Hint Ventsim Visual will store a custom colour and data value range for each type of data type This setting is saved with the Ventsim Visual file Levels w CET Si Selects which levels elevation ranges are displayed on screen To select or de select all levels choose the check box adjacent to the Level Name To change a level name right mouse click on the existing level name and type in the new name Air Types Fa Selects and colours the air types to be shown on screen Air types are designed to allow the user to colour airways according to air quality or purposed for example fresh or exhaust air Air Types behave in much the same way as primary or
418. ure for a surface exhaust fan or a Fan Total pressure for an equivalent underground fan in the airway This is similar to a duty point for a fan For a surface exhaust Fan the Fan Static Pressure is arguably the critical pressure value as the velocity portion of the Fan Total Pressure is lost to atmosphere A fixed flow will give a Total Collar pressure value for a fan This is equivalent to the Fan Static Pressure if the fan is a similar size to the airway shaft however this correlation will change for differing fan diameters For an intake or underground fan the fixed flow with provide a equivalent Fan Total Pressure value Required Power The power value will utilise the default efficiency set in the Settings Menu and describe a minimum motor size shaft power for the required fixed flow and estimated power electrical consumption for the fixed flow Annual Fix Cost The annual cost figure is derived from the power cost per kilowatt hour set in the Setting Menus for a fixed flow or pressure operating at the duty point continuously for a full year 9 7 2 Pressure Describes various pressure conditions at either end of the airway Information Ventsim Visual User Manual Page 111 Relative Pressures Barometric Pressures Pressure Loss 9 7 3 Heat Data Temperatures Sigma Heat Ventsim Visual User Manual The pressure at either end of the airway in relative to the equivalent surface pressure at the same elevation Negat
419. useful fan static pressure by increasing diffuser size and reducing exit velocities File Edit Heat Gain Losses show the addition and removal of heat into the mine atmosphere Note that while autocompression is a significant heat addition to deeper mine the heat is removed when air travels back to the surface Also note exhaust fan heat on surface fans has been deliberately excluded from this summary as the heat does not directly affect underground atmosphere Heat Gains 10 019 1 kW Heat Losses 2 009 9 kW Autocompression 99 Moisture Gain shows the addition of moisture to the underground atmosphere Note that in most cases moisture is due to either evaporation from rock strata or from diesel engine Figure 5 12 Mine Summary Graphs latent heat Ventsim Visual User Manual Page 57 5 6 1 5 6 2 9 7 1 Live VIEW Ventlog Fans Connect Import Stations Export Stations 5 6 Connect Menu A selection of tools to connect to external data sources Sorne tools may not be available unless purchased as an added extra LiveVIEW is a Ventsim module designed to connect to external data sources such as SQL databases Excel or Access data files or text files It is commonly used to connect to data coming from live underground sensors The data can be mapped and displayed within a 3D Ventsim model and can even be used to simulate new results based on the connected data
420. w nodes This will only happen in the drawing mode If airways are imported from a DXF for example crossed airway junctions will not automatically be detected To draw in the third dimension up or down in elevation where there is not an airway above or below to click to first draw the airway to the desired horizontal plan location then press the Shift key The Edit Plane will turn semi transparent and further movements of the mouse will occur in a Vertical plane parallel to the computer screen The Edit Plane will follow Ventsim Visual User Manual Page 29 4 5 3 Manual Coordinate Entry the vertical movement assisting in showing where the cursor is in relation to other airway elevations In addition the numbers in the lower left status bar will show the elevation and coordinates of the point KE Ventsim Visual I Beta Be Aen ampie Metal File Edt View Sevedwews Run Connect Tools Setting Window Help Fedora SSE 67 BGs rowan PO iy HONLRS 9F U00 0 05 A v sa Ki Favourite gt Levels vim T Aow gt Quantity gt m s all e H H BO OO coords 1573 1E 16535N 652 Status Compressible Yes NVP Yes airways 529 Figure 4 5 Picture showing inclined airway being drawn down to the elevation of the level below Airways can be manually added moved or copied by selecting a manual coordinate entry system To activate this system while in draw mode click on an airway end o
421. w the effect of the Simplify Function to reduce airway dotg EE 164 Fige 15 6 PIACING G fIXCO FIOW TGA UW GY a AAA AAA ai 166 Figure 15 7 Example of import error after simulation resulting from misaligned ends or unjoined nuodes 166 Figure 15 8 Example showing ventilation duct into blind heading e 167 Figure 16 1 EXGIIDIC of AICC Es a ASAS ee 171 Figure 16 2 Auxiliary ventil tion Oof OU EE 172 Figure 16 3 Colours showing the relative internal pressure of the durften 172 Figure 16 4 IVIGIO DIC DUCES ia AAA AAA AAA AAA AAA 173 Figure 10 5 POFEHGNY GHONGING CNS GUCE EE 173 PIGUIFE 16 6 eege e Ee EE 173 Figure 17 1 Example of contaminant sourcing narrowing down a smoke source 176 Figure 18 1 Example of Blasting Gases at a monitor location EE 179 Figure 18 2 Placing a contaminant in an GW GY ito 180 Figure 19 1 Inline Concentration represented by the green con 185 FIQUIFETS 2 EXOIMDIC Of Nected GOS EE 186 Figure 19 3 R n the GAS SIMUIATION OPO WEE 187 Figure 19 4 Change the text and colour to show gas concentrations EE 188 Figure 20 1 Example of Heat in mine calculated by Ventsim after simulation EE 190 Figure 20 2 Example of an inline cooler chilling ALL airflow cssccsescssessescssssscsssscsseseesenseseuseseusesscscsscssescsseseesneesenseseusessesenseseseesseuseneeseneeseneesees 194 Figure 20 3 Example showing same inline cooler chilling only 40 UirflOW oocoocccocccooonononnnonanonanorornnonanorononoonnonnn corno nonnn
422. with the true vertical line then it is vertical The true vertical line can also assist in locating airways directly under or over other airways at different elevations by observing where the line intersects airways above and below the current point being edited To simplify construction of airways initially all drawing moving and copying of airways defaults to the horizontal Edit Plane regardless of the orientation of the view screen To assist the user further airways being drawn or moved will automatically click and join to airways under the mouse cursor even if at different elevations or distances away Hint To quickly change the view from horizontal plan view to vertical section view press the F2 button If airways are drawn in isolation not connected to other airways they will use the default airway settings specified in the Settings form If airways are drawn connected from another airway they will inherit the settings from the airway from which they are drawn Airways can be drawn from another airway end node or from any other point along an airway Ventsim Visual will create a new node or junction if none already exists Hint Ventsim Visual can detect whether an airway being constructed crosses the paths of other airways For example if a long airway is drawn from one point to another over which it crosses the paths of existing airways Ventsim Visual will join this airway into the crossed airways with ne
423. wo regions a long way apart for example data may have been imported into Ventsim Visual from a different coordinate system The Fit All may not be able to accommodate the range of data attempted to be shown or the camera may be too far away to view the data effectively Ensure all data is in the same coordinate region before it is loaded or merged Resets all hidden levels layers and airway data and displays the entire model Occasionally a model may have hidden or semi transparent airways set from a previous action Show all will quickly bring the entire model back to full view Show A will force Ventsim Visual to show all elevations of airway data in your model even if they are outside of the ranges specified in the Leve Database Resets the graphics display adaptor and re establishes the graphics on the screen Some types of hardware graphics display adaptors may occasionally corrupt or fail to show the Ventsim Visual User Manual Page 48 9 3 4 9 3 5 9 3 6 5 3 7 9 3 8 Quick View screen graphics particularly if the computer has been brought out of hibernation sleep or screen saver This option in most cases should recover the graphics Quick Views can quickly be saved and recalled sequentially outside of the normal Saved View system Quick views are not added to the Save View menu selection The views can be quickly recalled at any time using the arrow keys The function primarily assists with navigation of l
424. y clicking the Primary Layer button and entering a new name or colour in the Preset spreadsheet Secondary Layer Sets the secondary layer type of the airway Once set secondary layers can be independently displayed using the Display Manager The name of the secondary layer can be changed by clicking the Secondary Layer button and entering a new name or colour in the Preset spreadsheet 9 4 4 Airway Attributes Sets resistance friction factors and shock loss factors for an airway The sort order of the attribute items in the list boxes can be specified in the Preset Spreadsheet Attributes Resistance 0 00041 AUTO e Na2 m8 Friction F 0 0025 DEFAULT v kgim3 Shock Eq 0 0 AUTO m Figure 9 7 Resistance Friction and Shock Factors Resistance Sets the resistance for an airway Resistance can be set to automatic preset or fixed Ventsim Visual User Manual Page 97 Auto matic allows Ventsim Visual to calculate the resistance automatically from the airways size length and wall friction factors Preset values can be selected from the resistance list Preset values are added to the underlying automatic resistance value To create a new Preset Resistance or change an existing one select the Resistance Button to enter the Preset Spreadsheet and enter or change any existing resistance values from the Preset Spreadsheet When the Preset Spreadsheet is closed the new preset resistances will be available in th
425. y holding the left mouse button and dragging the box around the airways within the desired elevation Ventsim Visual User Manual Page 115 10 1 5 Show All 10 1 6 View 10 1 7 Select All airways outside the elevation range will be hidden or made transparent The level of transparency can be adjusted from the Colour Palette Manager HINT Airways outside of the normal range of the LEVEL elevation database will be displayed as invisible or transparent The LEVEL database should have a least one level which encompasses all elevations of airway data in your model S Y Ventsim Visual Blue_sky vsm VentSim Demonstration Network File Edit View SavedViews Run Tools Window Help 1d ADS Jegen Zem PS SGOOOOSHG Deo O60 0S mectre Wime d Teen Units m3 s Coords 8804 6 73864 N 7572 Air simulation successful Figure 10 1 Model example before level selection Y Ventsim Visual Blue_sky vsm VentSim Demonstration Network E a a S 2 EE Die Edit View SavedViews Run Tools Window Help 1 Dea AA zl GEIER Quantity Paz D Geteste Test s o S60 0 Units m3 s Coords 149 8E 3600 8N 7577 Air simulation successfull Figure 10 2 Model example after level selection Hint Ventsim Visual initially defaults to displaying a 10 metre window range around the selected levels Airways outside of this range will not be displayed or will be made transparent The r
426. y State Steady State Contaminant simulation allows tracking the concentration of contaminants through a ventilation model Ventsim Visual has a number of different types of contaminant simulations to enable users to predict the paths of any sort of gas dust smoke stench gas or even fresh air through a mine and may assist in emergency planning production design and to improve blast clearance times SR RER Contaminant DPM Gas Reverse Contaminant Find Source Clear Contaminantes 17 1 Introduction Simulation of contaminants through underground mines can be difficult to predict particularly if simulations are required to take into account the complex boundary and mixing behaviours of contaminants traveling through a three dimensional airway Ventsim Visual uses a relatively simple algorithm which distributes contaminants in a linear velocity fashion and assumes perfect mixing at intersections This method is considered suitable for high level studies through broad mine areas but is not recommended for analysis of contaminant diffusion on a small scale level In this case a computational fluid dynamic simulation may be better suited A number of different simulation techniques are offered to provide users with a host of tools to analyse the tracking of air and contaminants through a mine Contaminants can either be specified as an in line concentration of contaminant within the airway or they can be injected into an
427. y clicking the button adjacent to the layer name Primary Layers consist of up to 250 layers It is intended that the Primary Layers be used for identifying types of airways For example Layer 1 could be Primary Shafts Layer 2 could be Main Airways Layer 3 Raises Layer 4 Stopes Layer 5 Minor Airways etc 15 6 2 Secondary Layers Secondary Layers also consist of 250 discreet layers It is intended that the Secondary 15 6 3 Using Layers Layers be used for isolating parts of a model that could be viewed independently from the rest of the model As mentioned above this could include working areas stope raises declines or any other feature of interest There is no limitation on the number of airways belonging to a layer however an airway can belong to only one secondary and one primary layer Primary layers and secondary layers can be set and viewed independently of each other See the Metal Mine example BLUE_SKY VSM examples that comes with Ventsim Visual Hint To quickly save and recall a layer state use the Save View function to save and recall views with the Primary and Secondary Layers settings The easiest way to use Layers may be to create the model first all airways will default to Layer 1 of both Primary and Secondary Layers and then editing individual or group airways to change the layers to the desired number Hint The Edit Box has a function which will select and group all similar airways for example all
428. y durech beneath the fan For a fan with an equal diameter to the airway this equates to the Fan Static Pressure requirement however caution should be used for this interpretation because differing fan diameters will alter fan static pressure requirements A fan manufacturer will normally be able to utilise the collar total pressure value to an equivalent fan pressure The Fan Total Pressure requirement will be a function of the discharge size and velocity of the fan as well as any resistance and shock losses in the fan and structure between inlet and outlet Thereofre the fan manufacturer will need to take this into account when selecting a suitable fan Also note that the simulated pressures provided will be influenced by the simulated Fan or Airway Discharge diameter evas so ensure this is noted and specified when quoting the duty point summary It is important to note that fixed flows contribute to model power consumption and heat in much the same way as fans The fixed power and heat within a model is summarised from the Run Summary menu item When calculating power and heat for a fixed airflow the default fan fix efficiency from the Settings Menu is used More information on fixed airflow and pressure is available from the Edit Box functions Finally when specifying a fan duty point based on a fixed airflow it is important that the air density the fixed flow was simulated in is noted Fan performance varies substantially in different
429. y self contained pressures and energies placed within the model to distribute flows are entirely consumed by the airways in the model No ventilation energy is lost to outside sources File Edit View Saved Views Run Tools Help DEB OOS armor Jouanty BA ZOOOORBSV De S Units m3 s Coords 434 4E 590 9N 523Z Figure 15 1 Example of a Closed Model Open Model An open model has at least two airways which connect to the surface at least one of which is an intake airway and another which is an exhaust airway Most if not all mines will be established as open models Airflow that exits an exhaust airway in no way influences the pressure or temperature of the airflow which enters an intake airway Airflow velocity pressures and energies lost from an exhaust airway are assumed lost to the model system To link any airway to the surface simply use the Connect to Surface function under the Edit Form FE pu Ventsim Visual O pen vsm File Edit View SavedViews Run Tools Window Help 10644140909 Jugen Jomiy P OOOOSHI F f Units m3 s Coords 459 1E 749 8N 523Z Figure 15 2 Example of an Open Model 15 3 Initial Model Construction Airways can be constructed in a number of ways e Manually draw scaled airways with the mouse using the toolbar functions Ventsim Visual User Manual Page 159 15 3 1 Manual Scaled Construction e Manually draw schematic airways with the mouse using the tool
430. yed if they have been correctly switched off for this stage then choose the EDIT gt PASTE AIRWAYS TRUE same position menu A copy of the airways should now appear in the new stage which can be independently modified without affecting the same airways on other stage Edit View Saved views Kun Undo Ctrl 2 Redo Tab Copy Airways Alt C Paste Airways True Alt V Paste Airways Loc Copy entire al Simply drawing a new airway with the ADD button or converting a DXF centreline will add an airway unique to the currently selected stage unless an airway is drawn from an existing airway in which case it adopts the existing airway stage settings These airways can remain on this particular stage only or can be later selected and set to appear on other stages 22 4 Suggested Tips for Developing Staged Models There are many ways to utilise staging and users are encouraged to use methods that suit their design techniques While not recommended it s possible to simply copy an entire model onto a new blank stage using the previous method Because all airways are copied then any modifications can be done in either stage without affecting the other stage While this method is probably safest for beginners it has the disadvantage of creating duplicates of every airway for every stage which can reduce available program memory Ventsim Visual User Manual Page 204 22 4 2 Shared Models particularly for large models In
431. yed on the screen For example airflow volume velocity and massflow could be displayed on each airway from a favourite If favourites are used for colours only the first favourites item in the list will be used To create favourites press the Ki button and add remove or edit the favourites in the left hand column The favourite name and the type of data under each selected favourite can be defined in the right handle panel The Text and Colour options define whether the favourite will appear in the text and or colour selection boxes Favourite Items Name Airflow Che goa Favourites can be displayed on the screen by selecting the favourite options from the drop down list File Select Airways Tools Shrink sa Ge OO a elo General E Arfow Pressure i Fans and Fixes s Termodyn amics Dsplay Favourtes Arfow s 8 Ventsim Visual User Manual Page 87 Con e 8 58 2m3 s 27 ils 79 93 kg s Because the display can become cluttered with too much data favourites can also be displayed only on individual airways with a text box panel To show a selected favourite on an individual airway EDIT the airway switch to the INFORMATION panel and select the desired favourite from the list 8 1 5 Display Manager Shows the Display Manager dialog box which floats on top of the Ventsim Visual windows and can be kept open at all times if desired The Display Manager control provides o
432. ynamic Fixed Release Specifies a constant concentration release of contaminant into the airstream for a specified number of seconds Linear Decay Specifies a reducing concentration release of contaminant into the airstream for a specified number of seconds The concentration initially starts at the specified amount and decreases at a linear rate over the specified number of seconds Ventsim Visual User Manual Page 108 Logarithmic Decay Specifies a logarithmically decreasing concentration release of contaminant into the airstream for a specified number of seconds This means the concentration of contaminant will start at the initial concentration and rapidly decrease over the initial time frame with a longer lower concentration period after that Explosive Amount The amount of explosive to place for dynamic contaminant simulation The higher the amount placed the more contaminant that must be dispersed into the model during simulation Dispersion Rate The logarithmic factor rate at which contaminant will be dispersed This does not impact the mass volume of contaminant entering the model but rather the rate at which it escapes into the model airflow Higher values will simulate more rapid dispersion of contaminant from the initial contaminant source It does not affect dispersal rates once the contaminant has entered the main model airstreams 9 6 8 Sourcing Location Provides options for setting contaminant reports and simulating

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