"user manual"
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1. O O pun e 2 o 5 5 O O E 5 O o O LD WM O wem wem gt ainjesodwis pin 20 33 19 83 20 08 20th operation year 19 58 19 33 Heat rate transferred in bridge road 19 83 20 08 20 33 20th operation year 19 58 19 33 Example of output result produced with BRIDGESIM XLS continued Figure 5 5 BRIDGESIM user manual SUPSI DACD ISAAC page 27 Ground duct store monthly heat balance and temperature levels 50 20 fluid loading c us meanductstore 18 30 fluid unloading 16 20 14 2 2 O 10 ien eb S 0 10 3 P s E o t 20 stored in duct store 6 E Oo 30 4 0 recovered from duct store 40 2 50 0 c C gt Q0 O Z O m Z gt C c c m gt m T 2 zr 6 0 2 502075 o 20th year Figure 5 5 Example of output result produced with BRIDGESIM XLS continued Other macros in BRIDGESIM XLS allow the user to visualise results of multiple simulations produced with the TRNSED application BRIDGESIM BRIDGESIM user manual SUPSI DACD ISAAC page 28 6 Input parameters for the bridge 6 1 Introduction The input parameters for the bridge are generated with the TRNBuild programme delivered with the BRIDGESIM package It is the demo version of the actual TRNBuild programme of the TRNSYS package The TRNBuild demo version allows the user to define and calculate all the required bridge2. unlike the HORIZONTAL orientation the UNDER orientation corresponds to the bottom face of the bridge and no solar radiation is received Orientations No Orientation Properties Figure 6 2 Input parameters in TRNBuild as entered in the various screen interface The top part of the bridge and bottom part of the bridge are simulated with two wall which are respectively defined as SURFACE and SOTTO see figure 6 3 and 6 4 It can be noticed that a bridge surface of 1 000 m is defined in TRNBuild In BRIDGESIM this surface has to be entered together with the actual bridge surface SROAD so that the thermal performances of the bridge can be scaled with the area ratio BRIDGESIM user manual SUPSI DACD ISAAC page 31 ALES Regime Data TT T zone volume m 3 Infiltration Ay Heating s Gains 4 Humidity SE Initial Values capacitance AG kJ K 3 Ventilation i Cooling Comfort Walls Windows Area Category Area Category JuValue g Value im SURFACE a 1000 00 EXTERNAL Add Delete wall type SURFACE news r area Wn m 2 incl windows category EXTERNAL geosurf ask 6 wall gain nl Wh orientation HORIZONTAL RR view fac to sky ER g Regime Data zone volume Fm m 3 M Infiltration 4 Humidity n Initial Values capacitance 3 kJ K FF V
3. Scuola Universitaria Professionale della Svizzera Italiana Dipartimento Ambiente Costruzioni e Design Istituto Sostenibilit Applicata Ambiente Costrutivo gx E BRIDGESIM Simulation Tool for the System Design of Bridge Heating for Ice Prevention with Solar Heat Stored in a Seasonal Ground Duct Store User Manual Dr Daniel PAHUD ISAAC DACD SUPSI Lugano February 2008 Switzerland SUPSI DACD ISAAC page 2 Table of content 54 5 2 5 3 5 4 5 5 5 6 5 7 5 8 6 1 6 2 6 3 6 4 PC and System Requirement 2 cccesecceeseeceeeeeeeeeeeeeeeeeeeaeeeeeaeeeoeaeeeneaseeoeaseeeenseeeneeeoenes 3 Installation Procedure epe ER 3 uievAeRnruaasldeilllp MP 4 Limitation of the Technical Support eeeeeeeeeeieeeee esee seien nennen nnn 4 The BHRIBGESIM Simulation TOOL issus c Qe scva s Qe ax uo ndn n cra a Cr rera i Qr a cuo sand era sav saria c 5 Introduction er T EET 5 BRIDGESIM System Layout Y co cnra nto la rene adn tagen n t den I t t ne 5 BRIBGESIM System GOnllol cdi oiiire Msn eirge diate 6 BRIDGESIM System Simulation Tool c ceecceeeeeee eee eee eee e seen eeeeeaeaeeeeeeaaaeeeeesaaaeeeeesaaaeees 7 Input Dats te BRIDGESIM x S5 facon aoa nsa fen aaa vga A ein rn wnat re Sten a 8 How to Run BBIDOESIMo es aeqne aderant Qu edu a ae aussie mace Or Hr tut OQ Ru 15 Output Da
4. RB1 thermal resistance of BHE type 1 The thermal resis tance of a BHE determines the temperature difference between the fluid and the ground in the immediate vicinity of the BHE under a given heat transfer rate A typical value for a double U pipe BHE is 0 1 K W m Such a value will induce a temperature difference of 5 K between the fluid temperature and the ground temperature at the borehole wall when a heat transfer rate of 50 W m takes place in steady flux conditions in the BHE K W m Internal thermal resistance of BHE type 1 RA1 internal thermal resistance of BHE type 1 A typical value for a double U pipe BHE is 0 4 K W m Diameter of BHE type 2 diameter of the borehole for the BHE type 2 m Number of BHE type 2 number of borehole heat exchangers for BHE type 2 Average active length of BHE type 2 average length of the borehole heat exchangers type 2 m Thermal resistance of BHE type 2 thermal resistance of BHE type 2 K W m Internal thermal resistance of BHE type 2 internal thermal resistance of BHE type 2 K W m Pipe configuration in BHE The two possible pipe configurations in the BHE are U pipe configuration the pipe installation in the BHE is formed by one or more U pipes placed close to the circumference of the borehole Coaxial pipe installation the pipe installation in the BHE is formed by a coaxial pipe NB the Rb and Ra values entered before must correspond to the correct pipe configurati
5. a fraction of the store depth FRISO the insulation layer on top of the store may extend beyond the store boundary FRISO give the radial extension of the insulation layer as a fraction of the store depth the store vertical exten sion Earth layer thickness covering the duct store DHP thickness of the earth layer that may cover the top of the store and the insulation layer if any m A zero value means no top earth layer 5 5 5 Ground Parameters Up to 3 different horizontal ground layers can be specified A ground layer is defined by its thickness the thermal conductivity and volumetric heat capacity of the ground and the Darcy velocity of the water contained in the ground layer The 16 entries are Mean undisturbed ground temperature at the surface TGRDIN initial temperature of the ground before the construction of the borehole field This temperature should be close to the annual average value of the ground near the surface A rough estimation is to use the mean annual air temperature at the surface plus about 1 K C Mean temperature gradient in the undisturbed ground DTGRND geothermal temperature gradient assumed to be constant It defines the temperature increase of the ground with the depth K km Thermal conductivity of ground layer 1 LG1 thermal conductivity of ground layer 1 W mK Volumetric heat capacity of ground layer 1 CG1 volumetric heat capacity of ground layer 1 MJ m k BRIDGESIM us
6. and solar gains collection m Bridge area defined in the bridge parameter input file bui area of the bridge surface that is defined in the bridge parameter input file The bridge parameter input file is produced with the demo version of TRNBuild The bridge area defined in the external bridge parameter input file must correspond to the value given here m Bridge parameter input file look in the Bridge directory for bui files external file containing the bridge model parameters This file is a text file that is created with the demo version of TRNBuild This file should be stored in the BRIDGE directory See chapter 6 for a description of the input parameter used in the demo version of TRNBuild Spacing between the imbedded pipes in the bridge surface BPIPE average distance be tween two parallel pipes imbedded under the bridge surface m Outer diameter of the imbedded pipes DEXTPIPE outer diameter of the pipes that are imbed ded under the bridge surface mm Inner diameter of the imbedded pipes DINTPIPE inner diameter of the pipes that are imbed ded under the bridge surface mm Thermal conductivity of the pipe material LPIP thermal conductivity of the material used for the pipes imbedded under the bridge surface W mK Thermal conductivity of the material in which the pipes are imbedded thermal conductivity of the material layer in which the pipes are imbedded It must correspond to the value used in BRE
7. entries are Water tank volume VOLTANK water volume of the short term water tank coupled between the bridge flow loop and the duct store flow loop m Water tank surface STANK area of the water tank through which heat losses with the ambient take place m7 Water tank heat loss coefficient HTANK average heat loss coefficient of the water tank W m k Mean ambient temperature around the water tank TAIRTANK mean ambient air temperature in which stand the water tank A mean constant value is assumed C 5 5 7 Circulation Pump Parameter The only entry is Total nominal electric power of the circulation pumps PELPUMP total electric power ab sorbed by all the circulation pumps of the system Simulations have shown that if the bridge cir culation pump is operating so is the duct store one and vice e versa As a constant flow rate is simulated the electric energy consumed by the circulation pumps is simply the product of the total electric power by the system operation time The secondary unit of the nominal electric power is kW BRIDGESIM user manual SUPSI DACD ISAAC page 15 5 5 8 Heating Curve Parameters The five entries correspond to TE1 TE2 TES TS2 and TS3 of figure 5 3 TS1 does not need to be entered as its value is set to TS2 Outdoor air temperature below which the bridge surface is heated TE3 outdoor air tempera ture below which the bridge is heated C Corresponding set point
8. level of the inlet fluid in the ground duct store when the store is unloaded in the case FLMEAN 0 If FLMEAN 1 the temperature level is the average inlet outlet kWh recovered heat from ground duct store 96 error in percent of the system heat balance The system heat balance is cal culated with QBSol QBHeat QSLoad QSUnload QLosses deltaQ 0 deltaQ is the variation of the internal energy of the water tank BRIDGESIM user manual SUPSI DACD ISAAC page 22 5 7 9 The Output File BRIDGESIM OU5 TTop C mean road surface temperature TBot C mean under bridge surface temperature TSurfi C mean surface temperature of inner surfaces of the fictive zone for the simula tion of the pipes in the bridge It corresponds to the mean bridge temperature in the plane of the imbedded pipes TAirZon C mean air temperature of fictive zone for the simulation of the pipes in the bridge Type56 parameters should be set so that TAirZon is quasi equal to TSurfi QRoad kWh thermal energy transferred through the road surface QUnder kWh thermal energy transferred through the under bridge surface QAbsO kWh solar energy absorbed in the road surface QStored kWh thermal energy stored in the bridge structure stored unstored QExFI kWh thermal energy exchanged by pipes imbedded in the bridge Error 96 error in percent of the fictive zone heat balance The fictive zone heat b
9. modifications of the bridge parameter file are performed save the file with another name with the command File Save As in the BRIDGE subdirectory You have then to generate the bridge input files with the command Generate Run TRNSYS Input file 7 References Fromentin A Pahud D Jaquier C et Morath M 1997 Recommandations pour la r alisation d installations avec pieux changeurs Empfehlungen f r Energiepfahlsysteme Rapport fi nal d cembre 1997 Office f d ral de l nergie Bern Switzerland Hellstr m G 1989 Duct Ground Heat Storage Model Manual for Computer Code Depart ment of Mathematical Physics University of Lund Sweden Hellstr m G and Nordell B 1988 A Posteriori Study and Redesign of Large Scale Borehole Heat Store in Lule Sweden Proceedings of JIGASTOCK 88 Versailles France Hellstr m G Sanner B 2000 Earth Energy Designer Users Manual version 2 0 http www blocon se earth htm Hopkirk R J Hess K Eugster W J und Knobel P 1994 Serso Pilotprojekt zur Sonnenener gier ckgewinnung aus Strassenoberflachen Technischer Bericht Bundesamt f r Stra ssenbau und Tiefbauamt des Kantons Bern Bern Hopkirk R Hess K und Eugster W 1995 Erdw rmesonden Speicher zur Strassenheizung bei Darlingen Schweiz Polydynamics Ltd Z rich Schweiz Klein S A et al 2005 TRNSYS A Transient System Simulation Program Version 15 3 Solar Energy Laboratory University o
10. thermal parameters The TRNBuild demo version generate text files that are then read as input data by BRIDGESIM The input parameters used in this section correspond to the bridge definition for the Serso project The bridge structure composed of various material layers is divided into two parts the bridge section above the pipe plane and the bridge section below the pipe plane see figure 6 1 Bridge top part thermal volumetric heat conductivity capacity asphalt 4 0 W mK 2 0 MJ Mm K mortar 2 4 W mK 2 4 MJ m K Pipe split Pipe plane in 2 parts mortar 2 4 W mK 2 4 MJ Mm K RES SOITOSTA IOIA OA M IM EM Cea e ute SEES Reinforced concrete 2 1 W mK 2 4 MJ m K plate eS ttt SOES 5th SR Reise fttt MO UII OT titres Re RM NN se es S eo eo 66 06606 OE EES insulation 0 056 W mK 0 2 MJ m K Bridge bottom part Figure 6 1 Section of the bridge in Serso subdivided into two parts above and below the pipe plane TRNBuild is used to define one zone whose temperature is the average bridge temperature in the pipe plane The heat transfer from the zone pipe plane to the environment occurs by transmission only through the top part and the bottom part of the bridge i e through two horizontal walls The heat transfer rate from the fluid circulating in the pipes and the zone is calculated with a thermal resistance Pahud 2007 This heat transfer rate is calculated in BRIDGESIM on the basi
11. to correspond to the pipe plane temperature in the bridge Figure 6 4 Input parameters in TRNBuild for wall SURFACE of the PONT thermal zone BRIDGESIM user manual SUPSI DACD ISAAC page 33 Bottom part of the bridge from the pipe plane to the bottom face of the bridge A wall type SOTTO Wall Type Manager front inside No Layer Thickness Type SCHAUMGLAS 0 100 back total thickness 0 540 m u value 0 459 W m 2K for reference only incl alpha_i 7 7 w m 2 K and alpha 0 25 w m 2 K 1 Solar Absorptance of Wall hone D back DE Convective Heat Transfer Coefficient of Wall Front Back userdefined userdefined A 720 kJ h m 2 K A 35 kJ4h m 2K wi Note the front convective heat transfer coefficient is fixed to an arbitrary large value 720 kJ hm K on the pipe plane face so that the surface wall temperature is very close to the zone air temperature as these two temperatures according to the bridge simulation model should be equal and have to correspond to the pipe plane temperature in the bridge Figure 6 5 Input parameters in TRNBuild for wall SOTTO of the PONT thermal zone BRIDGESIM user manual SUPSI DACD ISAAC page 34 Layer Type Manager m layer type BITUMENDAC Massive Layer C MasslessLayer C Active Layer C Chilled Ceiling Massive Layer conductivity 1
12. 25 Global system heat balance kWh year Solar losses Bridge solar collection Bridge sommer solar eff 10 096 electr ratio 37 4 3 800 Electricity pumps Solar radiation Bridge defreezing Bridge heating Bridge winter electr ratio 14 0 9 900 Electricity pumps Total electric energy for the pumps kWh y Global system ratio Duct store discharge Mean Max s 5 wm 23 kWh m y Max Mean 6 ss wm 24 kWh m y 98 Number of hours with temperature Ts below 0 C for the last simulated year Number of hours with Ts lt 0 C and Taria gt 4 C for the last simulated year Degree hours NTs for Ts lt 0 C and Taria gt 4 C for the last simulated year Heat extraction rate per meter borehole Annual extracted energy per meter borehole Duct store charge Heat injection rate per meter borehole Annual injected energy per meter borehole Duct store efficiency Road surface temperature Ts Figure 5 5 BRIDGESIM user manual mean operation year Store losses Duct store Stored unstored 200 Water tank losses Discharge duration 1795 hoursy Charge duration hours y hours y hours y 22 khy Example of output result produced with BRIDGESIM XLS continued page 26 SUPSI DACD ISAAC Inlet outlet fluid temperatures in duct store o g o Hs 2 o 2 lt o pun g o 2 o E o a8
13. 44 kJ hmK capacity Esa kJ kgK density BGG ka m 3 Layer Type Manager E layer type NORMALBETO Massive Layer C MasslessLayer Active Layer Chilled Ceiling Massive Layer conductivity Wm kJ hmK capacity kJ kgK density AGE ko m 3 Layer Type Manager WI aver type PIPELAYER Massive Layer C Massless Layer Active Layer C Chilled Ceiling Massive Layer conductivity 864 kJ hmK capacily Si kJ kgK density RE ka m 3 BRIDGESIM user manual SUPSI DACD ISAAC page 35 Layer Type Manager m layer type SCHAUMGLAS Massive Layer C Massless Layer C Act CT Massive Layer conductivity EE kJ hmK EE M kk DINAN Ko n 3 capacity density Figure 6 6 Input parameters in TRNBuild for the thermal characteristics of the various material layers No window no infiltration no ventilation no heating and no cooling is defined Only a convective heat gain for the zone PONT is defined see figure 6 7 It is the heat transfer rate from the fluid circulating in the pipes and the zone It is calculated in BRIDGESIM and given as input to the zone It has then to be defined as an input variable The convective heat gain is called SERPENTINS and is defined with the input variable QSER see figure 6 7 BRIDGESIM user manual SUPSI DACD ISAAC page 36 Gains Zone PONT Persons f off Cancel Comp
14. BRIDGESIM user manual SUPSI DACD ISAAC page 7 Bridge heating can only be switched on when the outdoor air temperature drops below a given value typically set to 4 C parameter TE3 The system operates in three different modes e mode rest the system is stopped e mode solar collection the system is switched on to collect the bridge solar gains and store them in the duct ground heat storage e mode bridge unfreezing the system is switched on to prevent the bridge from freezing by extracting heat from the ground duct store Two ON OFF controllers TYPE2 are used to control the solar collection and bridge unfreezing modes Mode solar collection condition to switch on the system Tair gt TES if Tm Treturn tuia gt DT1CST for example 10 K then pump is switched ON if Tm Treturn tiuigd lt DTOCST for example 4K then pump is switched OFF Mode bridge unfreezing condition to switch on the system Tar gt TE1 and Tai lt TES if Tse Tm gt 1K then pump is switched ON if Tsett Tm lt OK then pump is switched OFF Tm bridge temperature in the plane of the imbedded pipes C Treturn tluia fluid temperature in the short term water tank at the return pipe to the bridge C Tar outdoor air temperature C Tse Set point temperature for the forward fluid temperature in the bridge see figure 3 3 C Tse Set point temper
15. IM OU2 kWh collected solar heat from bridge only positive values C temperature level of the outlet fluid from the bridge when solar gains are col lected in the case FLMEAN 0 If FLMEAN 1 the temperature level is the av erage inlet outlet kWh stored heat in duct store only positive values C temperature level of the inlet fluid in the duct store when the duct store is loaded in the case FLMEAN 0 If FLMEAN 1 the temperature level is the av erage inlet outlet C mean duct store temperature kWh recovered heat from duct storage only negative values C temperature level of the outlet fluid from the duct store when the duct store is unloaded in the case FLMEAN 0 If FLMEAN 1 the temperature level is the average inlet outlet kWh heating in bridge only negative values BRIDGESIM user manual SUPSI DACD ISAAC page 21 THeatBridg TAirExtM C temperature level of the inlet fluid in the bridge when the bridge is heated in the case FLMEAN 0 If FLMEAN 1 the temperature level is the average inlet outlet C mean outdoor air temperature 5 7 7 The Output File BRIDGESIM OU3 tload tunload HHorTot SolEff DuctEff EffSys QLoadSpe PLoadSpe QUnloadSpe PUnloadSpe h duration of the system loading operation solar collection duration h duration of the system unloading operation bridge heating duration kWh m total inc
16. PID for the bridge definition W mk Thermal conductivity of the heat carrier fluid thermal conductivity of the fluid that circulates in the pipes W mK Nusselt number for the convective heat transfer from the fluid to the pipe wall NUFLUID a constant number is given for the convective heat transfer from the heat carrier fluid to the inner pipe wall and is defined here Fluid flow rate per square meter of heated bridge surface FLOWSPEC it is the total nominal flow rate flowing through the bridge divided by the heated bridge surface SROAD litre h m Heat carrier fluid density density of the heat carrier fluid that circulates in the imbedded pipes kg m BRIDGESIM user manual SUPSI DACD ISAAC page 11 Heat carrier fluid heat capacity specific heat capacity of the heat carrier fluid that circulates in the imbedded pipes kJ kg K 5 5 4 Duct Store Parameters The 19 entries are Diameter of borehole heat exchanger BHE type 1 DP1 diameter of the borehole for BHE type 1 m Number of BHE type 1 N1 number of borehole heat exchangers for BHE type 1 Average active length of BHE type 1 H1 average length of the borehole heat exchangers type 1 The active length of a BHE is defined by the bore length for which a radial heat transfer with the surrounding ground may occur In other terms it is the length of the borehole that is equipped with pipes m Thermal resistance of BHE type 1
17. Spacing between the imbedded pipes in E the bridge CG1 Volumetric heat capacity of ground layer 1 kJ Mm K MJ m K x 1000 CG2 Volumetric heat capacity of ground layer 2 kJ m K MJ m K x 1000 CG3 Volumetric heat capacity of ground layer 3 kJ m K MJ m K x 1000 DA1 Darcy velocity of ground water in layer 1 m s m day x 1 86 400 DA2 Darcy velocity of ground water in layer 2 m s m day x 1 86 400 DA3 Darcy velocity of ground water in layer 3 m s m day x 1 86 400 DEXTPIPE Outer diameter of the imbedded pipes m mm x 1 1 000 DHP Earth layer thickness covering the duct Lm store DINTPIPE Inner diameter of the imbedded pipes m mm x 1 1 000 DISO Insulation thickness on top of the duct store DP1 Diameter of BHE type 1 m m Table 5 1 List of the parameters that can be varied in a multiple simulation BRIDGESIM user manual SUPSI DACD ISAAC Parameter Short description Primary unit sec unit x factor DTOCST Lower dead band temperature for the so K K lar controller DT1CST Higher dead band temperature for the so K K lar controller DTGRND Mean temperature gradient in the undis K m K km x 1 1000 turbed ground FLOWSPEC Fluid flow rate per square meter of heated litre h m litre h m bridge surface Horizontal extension of the insulation FRISO i layer given as a fraction of store height H1 Avera
18. alance is calculated with QsiTop QsiBot QexFl 0 QsiTop is the thermal energy flowing from the pipe plane to the road surface QsiBot is the thermal energy flowing from the pipe plane to the under bridge surface 5 7 10 The Output File BRIDGESIM OU6 QDstToGrd kWh energy transferred to the ground by the vertical borehole heat exchangers QPipToGrd kWh energy transferred to the ground by the horizontal pipe connections QLossOut kWh total heat losses from the duct store QEDSTIN kWh duct store stored energy variation of its internal energy ERRDS error on the duct store heat balance calculation TmCenter C mean borehole temperature in ground duct store centre TmBorder C mean borehole temperature in ground duct store border QLossTout kWh heat losses through the ground duct store top side QLossSout kWh heat losses through the ground duct store vertical sides QLossBout kWh heat losses through the ground duct store bottom side 5 7 11 The Plot File BRIDGESIM PLT This file contains the time evolution of some temperatures and heat rates for the last year of the simulation period Hourly values of these quantities are written in this file only if the input parameter Print hourly values for last year is set to Yes Their labels are explained below The 11 columns of the file are BRIDGESIM user manual SUPSI DACD ISAAC page 23 Time hour time in hours from the first hou
19. ature for Tm see below The bridge temperature in the plane of the imbedded pipes Tm should lie between the outdoor air temperature Tair and the forward fluid temperature in the bridge Tse As the thermal resistance to the fluid temperature is significantly smaller than that to the outdoor air temperature Tse should be close to Tse On the basis of estimations and for commodity Tset is defined with the following relation Tsen TS3 0 75 Tset TS3 5 4 BRIDGESIM System Simulation Tool The simulation models used in BRIDGESIM are described in annex 1 and 2 of PAHUD 2007 The use of BRIDGESIM requires to define first the set point temperature curve as shown in figure 5 3 to heat the bridge In other terms the heat delivered using the heating curve assuming that the set point temperature is always met has to keep the bridge surface free from ice with the minimum BRIDGESIM user manual SUPSI DACD ISAAC page 8 amount of thermal energy necessary To help determine the heating curve the tool BRIDGEHEAT has been created which is a simplified version of BRIDGESIM The procedure to be followed is described in chapter 4 of PAHUD 2007 The input data to BRIDGEHEAT are the same as those for BRIDGESIM except for the non necessary components such as the ground duct store In the next section the input data to BRIDGESIM are listed 5 5 Input Data to BRIDGESIM The input data to BRIDGESIM concern all the information tha
20. blems related to the BRIDGESIM installation bad configuration or incompatibility of the personal computer system are not covered by the hotline Problems related to the use of the programme TRNSED are also not covered For each purchased programme the duration of the work spent for the hotline will not exceed 1 hour If the ISAAC thinks that the help demanded is actually consulting work or does not correspond to the help described above the client will be informed and an offer will be proposed the hourly price is fixed at 150 CHF hour or 100 EU hour BRIDGESIM user manual SUPSI DACD ISAAC page 5 D The BRIDGESIM Simulation Tool 5 1 Introduction The BRIDGESIM simulation tool is devised for the simulation of systems designed to unfreeze bridge carriage way with solar heat The energy concept involves a seasonal ground heat storage in the ground Solar energy is collected during summer stored in the ground with the help of a borehole heat exchanger field and recovered in winter for bridge defrosting Pipes are imbedded in the bridge carriageway for collection of aestival solar heat and heating to prevent ice or frost formation Apart from the electric energy for the circulation pumps the system is designed to operate without auxiliary energy The BRIDGESIM simulation tool has been developed and validated thanks to detailed measurements over a few years of such a system PAHUD 2007 BRIDGESIM is providing an opportunit
21. ctory where BRIDGESIM is installed It is recommended to create on the desktop a shortcut to the BRIDGESIM EXE file To do this search with Windows Explorer the directory in which BRIDGESIM has been installed Search the executable file BRIDGESIM EXE Select the file BRIDGESIM EXE with the mouse and right click on it A context sensitive menu appears Choose Send to and select Desktop to send the shortcut on the desktop You can then rename the shortcut to BRIDGESIM When BRIDGESIM is started i e when the programme BRIDGESIM EXE from the BRIDGESIM directory is executed the input file BRIDGESIM TRD is opened If you would like to work with the BRIDGEHEAT TRD input file close BRIDGESIM TRD and open BRIDGEHEAT TRD To check that BRIDGESIM is working properly run the input file BRIDGESIM TRD with the default parameter values To start the calculation choose TRNSYS Calculate in the menu The calculated results are stored in several files BRIDGESIM OUT BRIDGESIM OU1 BRIDGESIM OU2 BRIDGESIM OU3 BRIDGESIM OU4 BRIDGESIM OU5 BRIDGESIM OU6 BRIDGESIM PAR BRIDGESIM PLT BRIDGESIM LST and DST DAT They should be the same as the output results stored in the directory BRIDGESIMRESULTS An original copy of BRIDGESIM TRD is also stored in this directory 4 Limitation of the Technical Support A hotline is provided through e mail only use the e mail address daniel pahud supsi ch The hotline covers a reduced help service pro
22. e heating is stopped TE2 Outdoor air temperature below which the C forward fluid temperature is constant TE3 Outdoor air temperature below which C C bridge heating is allowed TGRDIN Mean undisturbed ground temperature at C C the surface Set point fluid temperature in bridge at TS2 C TE2 normally is the maximum value TS3 Set point fluid temperature in bridge at C TE3 normally is the minimum value p VOLTANK Water tank volume m m Table 5 1 List of the parameters that can be varied in a multiple simulation continued If a parametric study is performed with the borehole parameters RB1 RA1 N1 H1 it is best to define only one type of BHE A multiple simulation is started once a parameter table has been created using the command Run Table in the TRNSYS menu 5 7 Output Data from BRIDGESIM The output data from BRIDGESIM are written in four different files Two files contain the input information given to BRIDGESIM and possible error messages and two files contains the calculated quantities by BRIDGESIM Assuming that the file containing the input data is called BRIDGESIM TRD the following files are written e BRIDGESIM LST e DST DAT e BRIDGESIM OUT output data mean temperatures integrated quantities e BRIDGESIM OU1 output data mean temperatures integrated quantities e BRIDGESIM OU2 output data mean temperatures integrated quantities listing file e BRIDGESIM OUS output data mean te
23. entilation aay Cooling A Walls Windows Area Categos Area Category luValue g Value 1000 00 EXTERNAL Delete wall type SOTTO news 7 area o 3000 m 2 incl windows category EXTERNAL geosurf As FE wall gain nh kJ h orientation UNDER HORIZONTAL view fac to sky SS Figure 6 3 Input parameters in TRNBuild for the two walls SURFACE and SOTTO of the thermal zone PONT They have to be defined in this order so that wall 1 is wall SURFACE and wall 2 is wall SOTTO BRIDGESIM user manual SUPSI DACD ISAAC page 32 Top part of the bridge from the pipe plane to the road surface A wall type SURFACE front inside No Layer Thickness Type 2 BITUMENDAC Wall Type Manager back total thickness 0 090 m u value 5 021 W m 2K for reference only incl alpha_i 7 7 W m 2 K and alpha 0 25 w m 2 K Solar Absorptance of Wall x D back D Convective Heat Transfer Coefficient of Wall Front Back userdefined userdefined A 720 kJ h m 2 K A 36 kJ h m 2 K Cancel Save to user library Ri Dj igi Nj Note the front convective heat transfer coefficient is fixed to an arbitrary large value 720 kJ hm K on the pipe plane face so that the surface wall temperature is very close to the zone air temperature as these two temperatures according to the bridge simulation model should be equal and have
24. er manual SUPSI DACD ISAAC page 13 Thickness of ground layer 1 HG11 thickness of ground layer 1 Ground layer 1 must be larger than 0 3m the thickness of ground layer 0 that lies on top of ground layer 1 Ground layer 0 is a pre defined ground layer in which lie the horizontal pipes that connect the BHE to the system m Darcy velocity of ground water in layer 1 DA1 Darcy velocity of ground water in ground layer 1 This parameter determines the forced convection in ground layer 1 due to a horizontal re gional ground water flow A zero value means no forced convection m day The Darcy velocity in m s can be obtained by the product of the ground layer permeability in m s times the local horizontal hydraulic gradient of ground water in m m NB only a direct thermal interaction with the BHE is computed In other terms if the ground layer lies below the bottom of the BHE the effect of a regional ground water flow will not be computed If only the upper part of ground layer is crossed by the BHE the effect will be com puted in the upper part only The thermal influence will be then propagated upwards and down wards by pure heat conduction NB the full influence of a ground water flow is only calculated if the two last parameters from the ground parameter block are switched to YES Thermal conductivity of ground layer 2 LG2 thermal conductivity of ground layer 2 W mK Volumetric heat capacity of ground laye
25. f Wisconsin Madison USA Koschenz M and Dorer V 1996 Design of Air Systems with Concrete Slab Cooling Room vent 96 5 International Conference on Air Distribution in Rooms Yokohama Japan Mazzarella L 1993 Duct Thermal Storage Model Lund DST TRNSYS 13 1 Version 1993 ITW Universit t Stuttgart Germany Dipartimento di Energetica Politechnico di Milano Italy Pahud D 1993 Etude du Centre Industriel et Artisanal Marcinhes Meyrin GE Rapport fi nal GAP et CUEPE Univ de Gen ve Pahud D 2007 PILESIM2 Simulation Tool for Heating Cooling Systems with Energy Piles or multiple Borehole Heat Exchangers User Manual ISAAC DACD SUPSI Switzer land Pahud D 2007 Serso stockage saisonnier solaire pour le d givrage d un pont Rapport fi nal Office f d ral de l nergie Berne Suisse Pahud D and Hellstr m G 1996 The New Duct Ground Heat Model for TRNSYS EU ROTHERM Physical Models for Thermal Energy Stores A A van Steenhoven and W G L van Helden eds March 25 27 pp 127 136 Eindhoven The Netherlands Pahud D Fromentin A and Hadorn J C 1996 The Duct Ground Heat Storage Model DST for TRNSYS Used for the Simulation of Heat Exchanger Piles User Manual December 1996 Version Internal Report LASEN DGC EPFL Switzerland BRIDGESIM user manual SUPSI DACD ISAAC page 39 Remund J and Kunz S 2004 Meteonorm Version 5 1 Global meteorological database for appl
26. for the forward fluid temperature in the bridge TS3 set value of the forward fluid temperature to the bridge when the outdoor air temperature is equal to TE3 C Outdoor air temperature below which the forward fluid temperature is constant TE2 out door air temperature below which the forward fluid temperature is constant C Corresponding set point for the forward fluid temperature in the bridge TS2 set value of the forward fluid temperature to the bridge when the outdoor air temperature is equal to TE2 When the air temperature is between TE2 and TE3 the forward fluid temperature is linearly in terpolated between TS2 and TS3 in function of the air temperature C Outdoor air temperature limit below which bridge heating is stopped TE1 outdoor air tem perature below which bridge heating is stopped Between TE1 and TE2 the forward fluid tem perature is constant and set to TS2 C 5 5 9 Solar Controller Parameters The 2 entries are Higher dead band temperature for the solar heat controller DT1CST higher dead band tem perature for the solar heat controller The temperature difference between the average bridge temperature in the imbedded pipe plane and the outlet fluid from the water tank has to be greater than DT1CST before the circulation pump can be switched on to collect solar gains K Lower dead band temperature for the solar heat controller DTOCST lower dead band tem perature for the solar heat contr
27. ge active length of BHE type 1 m m HG11 Thickness of ground layer 1 m m HG2 Thickness of ground layer 2 m m HG3 Thickness of ground layer 3 m m HTANK Water tank heat loss coefficient kJ h m K W m K x 3 6 LCOEPF Length of the horizontal pipes on top of ee Lam the duct store LG1 Thermal conductivity of ground layer 1 kJ h m K 2 W mK x 3 6 LG2 Thermal conductivity of ground layer 2 kJ hm K W mK x 3 6 LG3 Thermal conductivity of ground layer 3 kJ hm K W mK x 3 6 LISO Thermal conductivity of the insulation ma kJ h mK W mK x 3 6 terial LPIP Thermal conductivity of the pipe material W mK W mK N1 Number of BHE type 1 s NSERIE Number of BHE coupled in series Ec Nusselt number for the convective heat NUFLUID vanster from the fluid to the pipe wall PELPUMP Total nominal electric power of the circu kJ h kW x 3 600 lation pumps RA1 Internal thermal resistance of BHE type 1 K kJ hm K W m x 1 3 6 RB1 Thermal resistance of BHE type 1 K kJ hm K W m x 1 3 6 SROAD Heated bridge area m m Table 5 1 List of the parameters that can be varied in a multiple simulation continued BRIDGESIM user manual SUPSI DACD ISAAC Parameter Short description Primary unit sec unit x factor STANK Water tank surface m m TAIRTANK Mean ambient temperature around the C C water tank TE Outdoor air temperature limit below which C C bridg
28. ident solar radiation on bridge surface per square meter 96 solar heat collection efficiency of the bridge QSolBridge QSolar 96 duct store efficiency QUnloadStk QLoadStk system efficiency QHeatBridg QElecLoad QElecUnloa kWh m injected energy in duct store per meter borehole heat exchanger W m mean injected power in duct store per meter borehole heat exchanger kWh m extracted energy from duct store per meter borehole heat exchanger W m mean extracted power from duct store per meter borehole heat exchanger 5 7 8 The Output File BRIDGESIM OU4 TBSol QBSol TBHeat QBHeat QLosses TSLoad QSLoad TSUnload QSUnload ErrSys C temperature level of the inlet fluid in the bridge when the solar gains are col lected in the case FLMEAN 0 If FLMEAN 1 the temperature level is the av erage inlet outlet kWh collected solar heat from bridge C temperature level of the outlet fluid from the bridge when the bridge is heated in the case FLMEAN 0 If FLMEAN 1 the temperature level is the average inlet outlet kWh heating energy injected into the bridge kWh water tank thermal losses gt 0 losses lt 0 gains C temperature level of the outlet fluid from the ground duct store when the store is loaded in the case FLMEAN 0 If FLMEAN 1 the temperature level is the average inlet outlet kWh stored heat in ground duct store C temperature
29. ied climatology www meteonorm com Sommer M 1999 Serso Sonnenenergier ckgewinnung aus Strassenoberflachen Mess kampagne und Simulation des saisonalen Erdspeichers Zwischenbericht Bundesamt f r Energie Bern 8 SEL TESS and TRANSSOLAR TRNSYS distributors Solar Energy Laboratory SEL University of Wisconsin Madison 1500 Engineering Drive Madison WI 53706 USA http sel me wisc edu trnsys Phone 1 608 263 1589 Fax 1 608 262 8464 Thermal Energy System Specialists TESS 2916 Marketplace Drive Suite 104 Madison WI 53719 USA http www tess inc com Phone 1 608 274 2577 Fax 1 608278 1475 Transsolar Energietechnik GmbH Curiestrasse 2 D 70563 Stutgart http www transsolar com Phone 49 0 711 67 97 60 Fax 449 0 711 67 97 611 9 Acknowledgements The Swiss Federal Office of Energy is acknowledged for its financial support to the project Serso solar seasonal storage for bridge ice prevention in which this TRNSED application has been developed and validated BRIDGESIM user manual
30. ile look in the Weather directory for txt files this file contains weather data on a hourly basis for the location where the project is evaluated The weather data files are grouped in the WEATHER directory The weather data file to be chosen has the extension TXT The weather data file contains hourly values of one year meteorological data The first line must correspond to the first hour of the year Each line must contain in the order given below the following quantities separated by a space or a tab character It can be created with the programme METEONORM 5 1 Remund et Kunz 2004 using the user defined format e hour of the year e global horizontal radiation W m e diffuse horizontal radiation W m e global radiation in the tilted plane W m e diffuse radiation in the tilted plane W m e normal beam radiation W m e outdoor air temperature C e relative humidity of the air 96 e dew point temperature C e cloud cover fraction BRIDGESIM user manual SUPSI DACD ISAAC page 10 The tilted plane is the horizontal plane azimuth 0 and inclination 0 but with the effect of the horizon In Switzerland the far horizon can be calculated with METEONORM thanks to the site coordinate latitude longitude and altitude 5 5 8 Bridge Parameters The 14 entries are Actual bridge area to unfreeze SROAD actual area of the bridge surface that is equipped with pipes for heating
31. ir temperature of zone PONT or mean bridge temperature in the pipe plane NType 1 inside surface temperature of wall 1 wall SURFACE top bridge part NType 17 inside surface temperature of wall 2 wall SOTTO bottom bridge part NType 17 heat rate from inside surface temperature of wall 1 including convection to air zone and long wave radiation to surface 2 NType 19 heat rate from inside surface temperature of wall 2 including convection to air zone and long wave radiation to surface 1 NType 19 outside surface temperature of wall 1 NType 18 outside surface temperature of wall 2 NType 18 heat rate to outside surface temperature of wall 1 including convection to outside air and long wave radiation to sky NType 20 heat rate to outside surface temperature of wall 2 including convection to outside air and long wave radiation to sky NType 20 long wave radiation losses to sky of wall 1 outside surface NType 83 long wave radiation losses to sky of wall 2 outside surface NType 83 absorbed solar radiation on wall 1 outside surface NType 22 absorbed solar radiation on wall 2 outside surface NType 22 Input and output variables defined in TRNBuild for the simulation of the bridge The simulated heat rate transferred from the fluid to the bridge is the sum of output 4 and output 5 QSER BRIDGESIM user manual SUPSI DACD ISAAC page 38 6 4 Creation of the bridge input files Once all the
32. ities are calculated by the first simulation summary Qsolar kWh incident solar radiation on bridge surface QLoadStk kWh stored heat in ground duct store QLossStk kWh duct store heat losses BRIDGESIM user manual SUPSI DACD ISAAC page 24 QEDSTin kWh duct store stored energy variation of its internal energy QUnloadStk kWh recovered heat from ground duct store QHeatBridg kWh heating energy injected into the bridge QLossTank kWh heat losses from the short term water tank QElecLoad kWh circulation pump electric energy for solar gain collection QElecUnloa kWh circulation pump electric energy for bridge heating 5 8 Output Results with BRIDGESIM An excel file has been created with the name BRIDGESIM XLS in order to produce graphical output results from the output files created by BRIDGESIM It contains macros that automatically open the output files copy the content into the BRIDGESIM XLS file and close them The global system heat balance is produced together with various design quantities and files Figure 5 5 shows the various output results that can be produced Fluid temperature in bore flow circuit 25 O 20 o S n monthly maximum nthly minimum 9 10 3 IN UI E STA 012 3 45 6 7 8 9101112131415 16 17 18 19 20 Operation year Figure 5 5 Example of output result produced with BRIDGESIM XLS BRIDGESIM user manual SUPSI DACD ISAAC page
33. meters are Month for simulation start the simulation starts the first day of the chosen month Length of simulation duration of the simulation period The maximum duration is limited to 50 years BRIDGESIM user manual SUPSI DACD ISAAC page 9 Time interval for output results quantities can be calculated on a monthly basis or a yearly ba sis They are integrated heat rates or average values See chapter 5 6 for a complete descrip tion of the output results Calculate temperature levels with inlet outlet average this parameter determines if the aver age temperature levels are calculated with the inlet outlet means in bridge and store yes or not no Print hourly values for last year this parameter determines if the hourly values of some selected quantities are written yes or not no for the last operational year see chapter 5 6 for more de tails 5 5 2 Weather Parameters The four entries are Latitude of the location the latitude of the location where the project is evaluated Longitude difference of the location longitude difference of the location where the project is evaluated It is Lst Lloc where Lst is the standard meridian for the local time zone and Lloc is the longitude of the location in question For example Lst 15 for Switzerland and Lloc 8 33 for Z rich East is negative Altitude of the location the altitude of the location where the project is evaluated m Weather data f
34. mperatures integrated quantities input data related to TRNVDSTP e BRIDGESIM OUA output data mean temperatures integrated quantities e BRIDGESIM OUS output data mean temperatures integrated quantities e BRIDGESIM OUG output data mean temperatures integrated quantities e BRIDGESIM PAR calculated parameters e BRIDGESIM PLT output data evolution of selected variables BRIDGESIM user manual SUPSI DACD ISAAC page 19 When a simulation is completed the file BRIDGESIM LST can be viewed in the Windows menu of the TRNSED programme and the files BRIDGESIM OUT in the Windows Other files menu A plot can be made with the file BRIDGESIM PLT and viewed in the Plot menu 5 7 1 The Listing File BRIDGESIM LST This is the listing file written by TRNSYS All the information contained in BRIDGESIM TRD is written in the listing file together with some information related to the simulation itself simulation duration total number of call for each component warning message if any etc It should be noted that if an error makes a simulation to abort the corresponding error message is written at the end of the listing file It is recommended to read this file every time a simulation is terminated with an error 5 7 2 The File DST DAT This file is written by the TRNVDSTP component which simulates the borehole heat exchanger field It contains all the parameters used by this component together with informati
35. oller The temperature difference between the average bridge temperature in the imbedded pipe plane and the outlet fluid from the water tank has to be smaller than DTOCST before the circulation pump is switched off to stop collecting solar gains K 5 6 How to Run BRIDGESIM Once the data are defined as desired it is recommended to save the data before a simulation is started The input data are saved in the file BRIDGESIM TRD It is done in the File Save menu of the TRNSED programme A simulation is started in the menu TRNSYS Calculate A series of simulations can also be defined and then simulated The user is advised to read the help provided with the TRNSED programme It is found in the menu Help TRNSED Help and then look for the topic Parametrics Menu When a series of simulations is performed a New Table is created in the menu Parametrics All the parameters that can be varied are listed The user selects the desired parameter to be varied BRIDGESIM user manual SUPSI DACD ISAAC page 16 and defines the ranges of variations The units of the parameters must correspond to the primary units In table 5 1 are listed all the parameter that can be varied together with their primary units and the conversion factor from secondary units Parameter Short description Primary unit sec unit x factor BBORE Average spacing between the BHE Bore ii hole Heat Exchanger BPIPE
36. on Average spacing between the BHE BBORE average spacing of all the BHE in the two spatial directions of the ground area that contains the BHE m Pipe number in a cross section of a BHE number of pipes in a cross section of the BHE For a double U pipe BHE the number of pipes is 4 BRIDGESIM user manual SUPSI DACD ISAAC page 12 Inner diameter of one pipe average inner diameter of the pipes in the BHE m Number of BHE coupled in series NSERIE number of BHE coupled in series It defines the hydraulic coupling of the BHE and thus the flow rate per BHE The series of BHE are supposed to be coupled in the radial direction of the store from the centre to the border Length of the horizontal pipes on top of the duct store LCOEPF the length of the horizontal pipes on ground is the effective pipe length that connects the BHE to the pipe collectors This parameter is used for the determination of the heat transfer that occurs between the fluid in these pipes and the ground in the plane of the pipes The pipes are supposed to lie below the insulation layer on top of the store if any m Insulation thickness on top of the duct store DISO thickness of the insulation layer on top of the store if any m A zero value means no insulation layer Thermal conductivity of the insulation material LISO thermal conductivity of the insulation material W m K Horizontal extension of the insulation layer given as
37. on local process this parameter determines if the local effect of the forced convection is taken into account see below YES local effect of forced convection taken into account NO local effect of forced convection not taken into account The effect of forced convection is treated as the superposition of two effects e the global process a heat balance of the heat transfer by forced convection is performed on the boundary of the ground volume that is ascribed to the BHE The heat quantity transferred by forced convection to or from the ground volume is treated as a global temperature change of the ground tempera ture in the volume The global process takes into account long term effects which in particular determine the magnitude of a natural thermal recharge of the ground by a regional ground water flow e the local process for the case of pure heat conduction a temperature gradient takes place around the BHE when they are used to transfer heat with the ground As a result the heat transfer is limited by the presence of a local temperature difference between the BHE and the mean ground tempera ture If ground water flows across the BHE the temperature field will be shifted For a suffi ciently large flow the local temperature difference will be decreased and the heat transfer be tween the BHE and the ground improved The local process takes into account the improve ment of this heat transfer 5 5 6 Water Tank Parameters The 4
38. on on the fields used for the simulation of the heat transport in the ground 5 7 3 The Output File BRIDGESIM PAR This file contains some of the mean parameter values which are calculated and used for the simulation They are NEPF total number of borehole heat exchangers HEPF m average active length of all the borehole heat exchangers BBore m average spacing between the borehole heat exchangers FIoEPF kg h total mass flow rate through the bridge and the duct store flow circuits SRoad m total heated bridge area VolTank m short term water tank volume FLMEAN parameter for average inlet outlet FLMEAN 1 or not FLMEAN 0 when the mean temperature levels are computed 5 74 The Output File BRIDGESIM OUT Maximum or minimum values of some selected quantities are calculated on a regular time interval month or year PMaxSolBri kW maximum hourly thermal power recovered from the bridge solar thermal power PMaxLoaDST kW maximum hourly thermal power injected into the ground duct store PMinUnload kW as extracted heat is negative the minimum corresponds to the maximum hourly thermal power extracted from the ground duct store PMinHeatBr kW as heating energy delivered to the bridge is negative the minimum corre sponds to the maximum hourly thermal power injected into the bridge BRIDGESIM user manual SUPSI DACD ISAAC page 20 TfMinStk TfMaxStk 5 7 5 deg
39. r 2 CG2 volumetric heat capacity of ground layer 2 MJ m K Thickness of ground layer 2 HG2 thickness of ground layer 2 m Darcy velocity of ground water in layer 2 DA2 Darcy velocity of ground water in ground layer 2 This parameter determines the forced convection in ground layer 2 due to a horizontal re gional ground water flow A zero value means no forced convection m day Thermal conductivity of ground layer 3 LG3 thermal conductivity of ground layer 3 W mK Volumetric heat capacity of ground layer 3 CG3 volumetric heat capacity of ground layer 3 MJ m k Thickness of ground layer 3 HG3 thickness of ground layer 3 The thickness of ground layer 3 which is the lowest ground layer is supposed to extend downward as far as necessary for the requirement of the thermal calculations m Darcy velocity of ground water in layer 3 DA3 Darcy velocity of ground water in ground layer 3 This parameter determines the forced convection in ground layer 3 due to a horizontal re gional ground water flow A zero value means no forced convection m day Simulate forced convection on global process this parameter determines if the global effect of the forced convection is taken into account see below YES global effect of forced convection taken into account NO global effect of forced convection not taken into account BRIDGESIM user manual SUPSI DACD ISAAC page 14 Simulate forced convection
40. r of the year of the simulation start TairExt degree C outdoor air temperature HHGLO W m incident solar radiation on bridge surface TsBridge degree C surface temperature of the road TinBridge degree C inlet fluid temperature in the bridge flow circuit ToutBridge degree C outlet fluid temperature from the bridge flow circuit TmDuct degree C average temperature of the ground duct store TinDuct degree C inlet fluid temperature in the duct store flow circuit ToutDuct degree C outlet fluid temperature from the duct store flow circuit PBridge kWh h heat rate transferred by the flow circuit in the bridge PDuct kWh h heat rate transferred by the flow circuit in the ground duct store 5 7 12 Heat Balance of the System The quantities contained in the file BRIDGESIM OUT allows the user to establish an overall heat balance of the system A diagram of the energy fluxes is shown in Fig 5 4 Global system heat balance kWh year Solar losses Qsolar QLoadStk Bridge solar collection Solar radiation Bridge sommer electr ratio QLoadStk QElecLoad Store losses QElecLoad Electricity pumps QLoadStk QLossStk Ground duct store Stored unstored QUnloadStk Bridge defreezing Bridge heating Bridge winter QHeatBridg electr ratio QHeatBridg QElecUnloa QLossTank GElecUnloa Electricity pumps Figure 5 4 System heat balance of the system Water tank losses The heat quant
41. rectory where the compressed file is e g select the drive C MySavedFiles provided you have saved the BRIDGESIM zipped file in this directory You may also click on the My Computer icon in order to find the drive and directory where the file is stored To install BRIDGESIM you have to create a directory on your local hard drive It is recommended to created a new directory for example C BRIDGESIM without space characters in the name and path name and copy in this directory the BRIDGESIM ZIP file Unzip the file and be sure that the subdirectory structure is maintained If you already have TRNSYS on your computer it is not advised to install BRIDGESIM in the same directory Several of your original TRNSYS files would be overwritten and lost To remove BRIDGESIM from your computer simply delete the directory in which BRIDGESIM was installed One additional utility is distributed in an Excel file which requires the EXCEL programme to be used This is Bridgesim xls this file is devised to visualise the results of a simulation contained in the various output files produced with BRIDGESIM This file is stored in the BridgeSimResults subdirectory BRIDGESIM user manual SUPSI DACD ISAAC page 4 3 How to Start BRIDGESIM With Windows there are different ways of starting BRIDGESIM BRIDGESIM is started by running the executable file BRIDGESIM EXE It is important to run the BRIDGESIM EXE file from the dire
42. ree C minimum inlet fluid temperature in the ground duct store during opera tion degree C maximum inlet fluid temperature in the ground duct store during opera tion The Output File BRIDGESIM OU1 Integrated or average quantities of various quantities are calculated on a regular time interval month or year They are produced with the help of 6 simulation summary type components and written in 6 different files The results of the first simulation summary are written in the file BRIDGESIM OU1 The labels of each calculated quantity are for the first the simulation summary Qsolar QSolBridge QLoadStk QLossStk QEDSTin QUnloadStk QHeatBridg QLossTank QElecLoad QElecUnloa kWh incident solar radiation on bridge surface kWh collected solar heat from bridge kWh stored heat in ground duct store kWh duct store heat losses kWh duct store stored energy variation of its internal energy kWh recovered heat from ground duct store kWh heating energy injected into the bridge kWh heat losses from the short term water tank kWh circulation pump electric energy for solar gain collection kWh circulation pump electric energy for bridge heating A system heat balance can be performed with the following relation 5 7 6 QSolBridge TSolBridge QLoadStk TLoadStk TmDST QUnloadStk TUnloadStk QHeatBridg QSolBridge QLossTank QHeatBridg QLossStk QEDSTin The Output File BRIDGES
43. s of the zone pipe plane temperature inlet fluid temperature and flow rate and given as input to the zone BRIDGESIM user manual SUPSI DACD ISAAC page 29 model as a convective heat gain For this reason the thermal conductivity of the material in which the pipes are imbedded mortar is an input parameter to BRIDGESIM and must correspond to the value given in TRNBuild 6 2 How to start TRNBuild TRNBuild is started by running TRNBuild exe from the directory where BRIDGESIM is installed for example C BRIDGESIM Once the programme is started a bridge input file has to be selected and opened They are stored in the subdirectory BRIDGE for example C BRIDGESIM BRIDGE A file with the extension BUI has to be selected The parameters for the Serso project are defined in the bridge input file PONTx0 BUI 6 3 Input parameters to TRNBuild The bridge input parameters are shown in figures 6 2 to 6 7 with TRNBuild input parameter screens They correspond to the PONTx0 BUI input file BRIDGESIM user manual SUPSI DACD ISAAC page 30 TRNBuild interface for the bridge definition FT TRNBuild Manager B Project Only one zone is defined The zone is called PONT Two orientations are defined for solar radiation Project Project HORIZONTAL UNDER title MODELE DE PONT POUR SERSO description ZONE TEMPERATURE FLOTTANTE POUR LE PLA created ty DRE addess SAACEDACDESUPSI Comments
44. t can be varied by the user In particular the input data define the size and characteristics of the different parts of the system and the driving conditions which will condition the operation of the system In this chapter each parameter required to BRIDGESIM is described and explained The input data are grouped in 9 blocks e Simulation parameters e Weather parameters e Bridge parameters e Duct store parameters e Ground parameters e Water tank parameters e Circulation pump parameter e Heating curve parameters e Solar controller parameters The BRIDGEHEAT tool used to determine the heating curve only requires the input data of the amp three blocks Weather parameters Bridge parameters and Heating curve parameters BRIDGESIM and BRIDGEHEAT are TRNSED applications The input parameter values may either be given in the primary units which correspond to the unit assumed by TRNSYS or in the secondary units which are more convenient units for the user For example the primary unit of thermal conductivity is kJ h m K whereas the secondary unit is W mK All the units given in the following sections for the input parameters correspond to the secondary units When BRIDGESIM or BRIDGEHEAT is used it is highly recommended to set the units on secondary This is done by selecting Secondary Units in the menu TRNSYS of the TRNSED application 5 5 1 Simulation Parameters The five entries related to these para
45. ta from BRIBDGESIM sans nutre pn nr nrh Bn tnp un nn Eur uE n ae M xEMa RE EE AER RE REU RAE 18 Output Results with BRIDGESIM cucine aeree sn e ucc dud ede dude qu ei duit 24 Input parameters for the bridge ssmnennenreenenneeneenennnneee 28 IMC ADO ilo RE TE ETT TT TTE TITRE TT STET Re SAS CARE 28 How to start TIN ENN RM D p TM DIEI a a et ten 29 Input parameters to THNBulld cantent hen tn hun tx etn xa tk mea e aea xu xn RE REX EAR RR 29 Creation of the bridge input files 38 Referen6Ges asa tein Fel dE Haa EAE terrasse AVESSE suns ieaucudn anndudususndadn asetuaedaustedueumtuduteiids 38 SEL TESS and TRANSSOLAR TRNSYS distributors eese seen 39 Acknowledgements u susce ueeiir eo nasaian inanan ig Ee Kp kn Unt ebd UU p e t asp s UE DRIN E PR 39 BRIDGESIM user manual SUPSI DACD ISAAC page 3 1 PC and System Requirement BRIDGESIM was tested on a laptop Pentium 1 7 GHz and 512 MBytes of RAM with Windows XP Professional BRIDGESIM requires about 20 to 30 MBytes of hard disk space BRIDGESIM is a 32 bits programme and is not working with Windows 3 x BRIDGESIM is a TRANSED application of the TRNSYS package simulation tool made with the TRNSYS version 15 3 2 Installation Procedure All the necessary files are compressed in a single zipped file To install BRIDGESIM you may start the programme Windows Explorer and select the drive and di
46. uter Artificial Lighting i Other Gains Type Scale Geo Position SERPENTINS 1 Add Delete gain type SERPENTINS news scale n fi Gain Type Manager A heat gain called SERPENTINS is defined in zone PONT The heat gain SERPENTINS is purely convective and is defined as an input variable called QSER A f gain type radiative power E o kJ hr convective power E j 1 0SER kJ hr abs humidity A fo kg hr Lx Cancel Save to Library Bi el Ni SERPENTINS Figure 6 7 Input parameters in TRNBuild for the definition of the input convective heat gain in the zone PONT BRIDGESIM user manual SUPSI DACD ISAAC page 37 Finally output variables have to be defined for the bridge model The input output variables that have to be defined in TRNBuild are shown in figure 6 8 The output variables have to be defined in the same order as indicated User defined input in TRNBuild used for the simulation of the bridge QSER heat rate transferred from the fluid to the bridge User defined outputs in TRNBuild The outputs have to be defined in the order indicated below output 1 output 2 output 3 output 4 output 5 output 6 output 7 output 8 output 9 output 10 output 11 output 12 output 13 Figure 6 8 Calculate Transfer Functions Timebase Outputs Mo Zones Nodes Airlinks a
47. y to go beyond the realised practical experience and is designed for the sizing of such a system 5 2 BRIDGESIM System Layout The simulated system layout is shown in figure 5 1 Thermal simulations have shown that it is equivalent to the actual system layout of the Serso system shown in figure 5 2 short term water tank coupled in series 29 d Bridge with pipes Cireulation Short term imbedded in pump water tank road surface Ju Long term diffusive borehole store Figure 5 1 System layout simulated by the BRIDGESIM tool BRIDGESIM user manual SUPSI DACD ISAAC page 6 water tank VIT Short term Long term diffusive borehole store Bridge with pipes Md imbedded in pump road surface Figure 5 2 Simplified system layout of the Serso plant equivalent to the one simulated by the BRIDGESIM tool 5 3 BRIDGESIM System Control The mixing valve is only used when the bridge is heated in order to limit the forward fluid temperature in function of the outdoor air temperature according to the diagram shown in figure 5 3 Po e O0 set point temperature in bridge flow circuit for the prevention of ice formation AR Set point temperature Tset C PO O e 12 8 4 0 4 8 12 Outdoor air temperature C Figure 5 3 Control of the forward fluid temperature in the bridge in function of the outdoor air temperature when the system operates in the ice prevention mode bridge heating
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