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1. Solar Storage Tank w Heat Exchanger PARAT Auxiliary Tank H J Figure 5 System apparatus overview Mains Chiller System Draw Valve Ice Bath Heat Exchanger Key Assumptions In processing the data for this experiment there were several key assumptions that were made to simplify the calculations and provide reasonable results Current SRCC guidelines provide a standardized yet approximated profile of solar insolation ambient temperature and incidence angle on a given day regardless of location which can be found in Appendix E For laboratory conditions a standardized weather profile provides a good metric to compare multiple systems however for testing actual performance of systems this metric may not give accurate results for a given location The SRCC assumes in Section 7 3 of OG 300 the same conditions as the U S Department of Energy s test for water heaters with several modifications A standardized solar profile has been incorporated which contains the solar time ambient temperature solar radiation and incidence angle Each solar day consists of approximately 4700 Whr m which is about 15 less than the typical annual value in central Texas This profile simplifies the necessary calculations involved in determining total insolation on a surface as well as providing a standard to which all systems are subject regardless of location Domestic hot water usage is simulated by
2. APPENDIX D Uncertainty Calculations In order to provide our research with a solid statistical foundation an uncertainty analysis is performed using the guidance of the methods from Kline and McClintock and Coleman and Steele 17 18 These methods allowed the uncertainty in the volume of water drawn system uncertainty of the sampling components and the total uncertainty of our measurements to be computed The basis of the uncertainty comes from Equation D 1 which encompasses the fixed or systematic uncertainty and the random uncertainty or Br tSr D 1 The fixed uncertainty comes from manufacturer s data and is analyzed using Equation D SS OR Br es Oy D 2 The random uncertainty Sr many times is an approximation of noise drift and other uncontrollable phenomena in the devices Where the partial derivative of the process equation R represents the sensitivity coefficient which conveys how sensitive the process is to a variable with uncertainty Xi The root sum squares method is very important for compiling multiple uncertainties If the error of an instrument is not given it is usually assumed to be half of the smallest reading The following calculations for auxiliary and parasitic energy are performed for one entire test period The delivered energy uncertainty is calculated based on the average sampled temperature difference per energy draw 98 Single Tank Uncertainty Parasitic Energy bpar 0 002 Ac
3. Il IIl Div 1 groups A G e Manufactured under ISO 9001 2000 for Quality and ISO 14001 2004 for Environmental Management For liquids containing particles use only Signet Magmeters For systems with components of more than one material the maximum tem perature pressure specification must always be referenced to the component with the lowest rating Please refer to Wiring Installation Accessories and Fittings sections for more information 121 Automated Valve Manual Override The automated valve is located on the cold inlet of the auxiliary tank and has a three way bypass configuration that can be rotated 360 A visual indicator is located on the back and displays the current flow configuration as seen in Figure E1 The following procedure will be a guide to manually bypassing or incorporating the auxiliary storage tank Closed Q Auxiliary Bypass Figure E 1 Automatic valve manual override indicator and procedure l Identify whether the auxiliary tank is being bypassed or incorporated and which way the valve will need to be rotated Note It is crucial to observe and preserve the orientation of the indicator because there are multiple orientations possible when replacing it Zz Remove the indicator with a Philips head screwdriver A 3 8 in wrench is used to slowly rotate the drive shaft a quarter turn 90 The positions have been labeled shown in Figure E1 with a small indicator on the drive shaft however pre
4. 41 data has been entered the testing can begin LabVIEW will monitor system temperatures flow rates output power of the STCS and timing of the system Mains Chiller procedure Once the main storage tanks have reached steady state conditions and the beginning of the solar day is reached the mains chiller can be initiated by the following procedure The most convenient time to activate the mains chiller is during the first hour of insolation preceding the first energy draw l Fill the insulated container to the top with ice adding water until a thick slurry is formed More ice must be added to maintain a constant temperature of 0 C Ensure the thermocouple probe is inserted into the thermowell with good contact being made with the wall Note the probe must be connected to the controls before they are turned on to ensure the self test procedure operates appropriately With the isolation and gate valves closed from the storage tank filling procedure activate the controls by plugging them into an open 110V outlet The process variable will display the current temperature above the set point variable The pump will activate if the current tank temperature is above the set point and will deactivate when the set point is achieved Program the Dwyer Love controls to a set point of 13 8 C using the procedure found in Appendix F Note the set point is lower than the test specifications to account for mixing and temperature gai
5. Red 1 377x 10 129 The Nusselt number is found from the Dittus Boelter formula in Equation F 6 with n 0 3 for cooling E Nug 0 023 Red MaDe F 6 Nug 86 391 The internal heat transfer coefficient is found using Equation F 7 kH20 F 7 h e Nug 1 h 4696 53 2 mK The external heat transfer coefficient can be found by first solving for the Rayleigh number in Equation F 8 gB Thi Tc d Rag Se v a Rag 1 176 x 10 The Nusselt number for a heated horizontal cylinder in free convection is found from the method of Churchill and Chu in Equation F 9 Ta 0 387 Rau i F 9 Nudo 5 453 130 The free convection heat transfer coefficient of the ice bath is the found using Equation F k H20 ho aq o F 10 o ho ALSI oe mK Since this is a transient process the length of tubingpecified for simplification L 55ft 16 764m Given Equation F 11 the overall heat transfer coefficient can be found 1 i 1 o1 FAD ka dr Za kel ben dell ua W UA 137 87 K The average overall temperature difference is assumed AT 84 C The average heat rate for system can now be determined from Equation F 12 Q UA AT F 12 Q 1 103x 10 W The average time to cool water is predicted from Equation F 13 E e Q F 13 t 36 378min 131 The heat exchanger modeled is similar to an evaporator where the cold fluid remains the s
6. Solar Rating and Certification Corporation Cocoa FL 17 Kline S J McClintock F A Describing Uncertainties in Single Sample Experiments Mechanical Engineering vol 75 pp 3 8 Jan 1953 18 Coleman H W Steele W G 1999 Experimentation and Uncertainty Analysis for Engineers 2 ed John Wiley and Sons Inc Hoboken NJ 19 Incropera Frank Dewitt D 2002 Fundamentals of Heat and Mass Transfer John Wiley amp Sons Inc Hoboken NJ Chp 9 12 134
7. Union Panel Mount Tappings Performance Field 60Hz FLOW M H Performance Data Pere EN DE SE SR E Flow Range 0 6 GPM CR Head Range 0 5 Feet IN Minimum Fluid Temperature 40 F 4 C p 7 g Maximum Fluid Temperature 220 F 104 C 20 6 Maximum Working Pressure 125 psi Zu 5 Connection Sizes 1 2 Swt 3 4 Swe 3 4 NPT 5 Ts or Union 10 43 2 2 5 Ws el Gos dap Sher dom Ted T 0 5 10 15 2 25 30 35 4 45 FOR INDOOR USE ONLY FLOW GPM Do it Once Do it Right Taco Inc 1160 Cranston Street Cranston RI 02920 Telephone 401 942 8000 Fax 401 942 2360 ee Taco Canada Ltd 6180 Ordan Drive Mississauga Ontario LST 2B3 Telephone 905 564 9422 Fax 905 564 9436 TACO Inc Visit our website at www taco hvac com 111 sY313W QAY3H WLOl ve EZ ZZ be OZ GL SL ZL GL SL Vb EL Z LL OF 6 8B Z 9 G WR g 9 0 cL SL F oe 800 O bk 200 g900 e 900 gt soo O acoo O 8t p WdS MO 14 VS LS 8b Gb Z 6T Ve ce Of LE VE LE BSL St Sb H EW MO 14d SYOLVINIUID 00 OIE vee Z L 0 60 90 CO 00 1334 0V3H 1VLOL 112 Effective September 1 2003 Submittal Data Information Model 009 Cartridge Circulator Supersedes July 1 2003 Job Engineer Contractor Rep ITEM NO MODELNO IMP DIA GPM HEADFT HP ELEC CHAR Features Application R x R The Taco 009 is designed for a wide range of Res
8. direct drive low power consumption design is ideal for high efficiency jobs Pump Dimensions amp Weights A B C 5 11 16 144 5 1116 144 Optional OK if over 20 psi Flange Orientation IS 60 1 40 Permanent Split Capacitor Impedance Protected 3250 FLOW M H 4 5 7 35 te TOTAL HEAD FEET TOTAL HEAD METERS 0 5 0 15 20 2 3 35 4 4 FLOW GPM Do it Once Do it Right Taco Inc 1160 Cranston Street Cranston RI02920 Telephone 401 942 8000 Fax 401 942 2360 a Taco Canada Ltd 6180 Ordan Drive Mississauga Ontario LST 2B3 Telephone 905 564 9422 Fax 905 564 9436 TACO Inc Visit our website at www taco hvac com 113 SYS LSW OV3H WLOol 00 GO OL GL oz E Dr Ge ov SV os SS 09 Gg WEI Gl os Gg 06 S6 OO SOL OL FG ZS 0S 8v Ob VY CY OV BE GE VE CE OE BC 9Z VE zz OZ BIL GL VL Cb OL SaF ZC OD FLO0 eloo lt O ZLOO LL00 O oroo 600 O WdS MO14 Jit LH A lie LTL OCLVILLSOLCOL 96 O06 V8 BL 2L99 09 VS BY ck VDE OE Ve SL ZL 90 00 H E IW MO14 SYOLVINOUID 00 CIE RT 41344 0V3H 1VLOL 114 H Solaraide H E Solar Heat Exchanger Solar Tank or Electric Storage Water Heater Available in 80 and 120 Gallon Models gt 6 Year Limited Tank and
9. the least impact on the tests since it was only 0 1 C higher than the SRCC and DOE standards The water mains temperature highly influenced the amount of energy needed to maintain the stored water at the desired temperature Great care was taken to control this variable by implementing the mains chiller to bring the inlet water to a uniform temperature The DOE test does not specify a net quantity of energy drawn to simulate hot water usage but requires a fixed volume of water to be drawn instead The SRCC modified the test conditions from the DOE requirements to require the draws that simulate hot water usage be based on energy rather than volume This allows the ability to vary flow rate or draw volume to attain the correct net energy draw The auxiliary set temperature for the electric heating elements was the most sensitive variable in the test conditions and was also the most difficult to control due to the low resolution on the commercial thermostats A true average tank temperature cannot be measured by the surface mounted thermocouples placed near the thermostats The thermocouples do provide an approximation of the internal tank temperature however conduction through the metal tank can mask any temperature variation The solar storage tank did contain a threaded port into which a thermocouple was placed to measure the temperature in the middle of the tank bottom Figure 20 displays a picture of the thermocouple used to measure the bottom of
10. 0 1 2 12 53 6 0 0 2 3 11 51 8 0 0 3 4 10 50 0 0 0 4 5 9 48 2 0 0 5 8 8 46 4 0 0 8 9 8 46 4 315 100 60 9 10 11 51 8 470 150 45 10 11 13 55 4 570 180 30 11 12 15 59 0 660 210 15 12 13 17 62 6 700 220 0 13 14 19 66 2 660 210 15 14 17 21 69 8 570 180 30 15 16 21 69 8 470 150 45 16 17 21 69 8 315 100 60 17 18 20 68 0 0 0 18 19 19 66 2 0 0 19 20 18 64 4 0 0 20 21 17 62 6 0 0 21 22 16 60 8 0 0 22 23 15 59 0 0 0 23 24 14 57 2 0 0 107 Solene e Solene Chromagen Drain Back SOLAR WATER HEATING i SYSTEMS CERTIFICATION AND CERTIFIED SOLAR WATER HEATING SYSTEM RATING SUPPLIER Solene 927 Fern Street Suite 1500 Altamont Springs FL 32701 407 831 1941 407 831 1208 Fax VE SYSTEM NAME Solene Chromagen Drain Back SRCC OG 300 SYSTEM TYPE Indirect Forced Circulation Description Glazed Flat Plate Collector Differential Controller Tank Wrap Around Heat Exchanger with a Double Wall and Positive Leak Detection No Load Side Heat Exchanger Fluid Class I Freeze Tolerance 23 3 C 10 F Electric Auxiliary Tank Model Name Cert 300 4 Cert Date Collector Panel Collector Panel Name Total Total Solar Aux Manufacturer Panel Panel Tank e SE Tank Aren Area Ve Le Vol Ve mj bei rz Ee et A Solene Lac rz FstexeeDe sons ir sostsoe 197006 fsa fara fso far EES SLCRSODC 120DB XE 2006030F 117 2008 Solene ICH Hepat psp sucsopc sope xe 20060300 1272006 Selene sa
11. 80 1 454 120 32 SLCR40 74 80 1 303 80 49 i H an ji Id S Solar Tank Fun 0G300 System Reference 2006001C November 2008 Certification must be renewed annually For current status contact SOLAR RATING amp CERTIFICATION CORPORATION c o FSEC e 1679 Clearlake Road e Cocoa FL 32922 e 321 638 1537 Fax 321 638 1010 109 Solene e SLCR 40 SOLAR COLLECTOR CERTIFIED SOLAR COLLECTOR CERTIFICATION AND RATING SUPPLIER Solene 927 Fern Street Suite 1500 Altamont Springs FL 32701 MODEL Solene Chromagen SLCR 40 SRCC OG 100 COLLECTOR TYPE Glazed Flat Plate CERTIFICATION 100 2004 014C COLLECTOR THERMAL PERFORMANCE RATING Megajoules Per Panel Per Day Thousands of Btu Per Panel Per Day CATEGORY CLEAR MILDLY CLOUDY y MILDLY CLOUDY DAY CLOUDY DAY r CLOUDY DAY 23 Mierd 17 MJ m d 11 MJ m d 1500 Btu ft d 1000 Btu ft d eero a J Deo a s a E eoo LI E mp LC II A Pool Heating Warm Climate B Pool Heating Cool Climate C Water Heating Warm Climate D Water Heating Cool Climate E Air Conditioning Original Certification Date November 4 2004 COLLECTOR SPECIFICATIONS Gross Area 3 721 m 40 05 ff Net Aperture Area 3 469 m 37 34 ft Dry Weight 68 9 kg 152 Ib Fluid Capacity 38 1 1 0 gal Test Pressure 1103 kPa 160 psig COLLECTOR MATERIALS PRESSURE DROP Frame Aluminum Cover Outer Low Iron Tempered Glass Cover Inner None Absorber Material Tube C
12. Setscrew two turns using the hex wrench provided with the tool 2 Close the tool until the jaws just touch and increased resistance is felt This Is the pre load point 3 Turn the top Adjusting Setscrew until the distance between the raised marks on the handles is between 7 and 8 1 2 Inches for QCRT2T 3T JT and 4T The distance for QCRT5T should be 13 inches Tighten the bottom Locking Setscrew See Warning for QCRT2T 3T JT 4T and QCRTST tool 4 Make a test crimp connection and check it with the Go and No Go openings of the gauge If the No Go opening goes over the crimped ring the tool is too tight The distance between the marks should be decreased If the Go opening does not go over the crimped ring the tool is too loose and the distance between the marks should be increased 5 Apply a light oil to the pivot points each time the tool is adjusted Fallure to lubricate the tool will shorten Its life Adjusting Screw Locking Screw WARNING Increasing the pre load distance beyond 9 inches for the QCRT2T 3T JT 4T or 13 inches for the QCRTST will make the tool hard to use and shorten tool life because of excessive stress 119 Signet 8550 1 Flow Transmitter LLU 3 8550 090 1 Rev L6 06 English WARNING Remove power to unit before wiring input and out put connections Follow instructions carefully to avoid personal injury 1 Specifications Dimensions
13. Solar Hot Water and Your Home U S Department of Housing and Urban Development May 16 1979 8 Gas Appliance Manufacturers Association 1994 Consumer s Director of Certified Efficiency Ratings for Residential Water Heating and water Heating Equipment pp 138 218 9 Burch J Hendron R 2007 Development of Standardized Domestic Hot Water Event Schedules for Residential Buildings NREL CP 550 40874 Proceedings Energy Sustainability 10 ASHRAE Handbook HVAC Applications 1995 Inch Pound ed ASHRAE lt Atlanta GA 1995 pp 45 10 11 SRCC OG 300 2008 Operating Guidelines and Minimum Standards for Certifying Solar Water Heating Systems Solar Rating and Certification Corporation Cocoa FL 12 SRCC RM 1 1994 Methodology for determining the Thermal Performance Rating for Solar Collectors Solar Rating and Certification Corporation Cocoa FL 133 13 Beckman W A Duffie J A 2006 Solar Engineering of Thermal Processes SC ed John Wiley and Sons Inc Hoboken NJ 14 SRCC TM 1 2008 Solar Domestic Hot Water system and Component Test Protocols Solar Rating and Certification Corporation Cocoa FL 15 DoE 1998 Energy Conservation Program for Consumer Products Test Procedure for Water Heaters Final Rule Federal Register May 11 1998 vol 63 no 90 pp 25996 26016 16 SRCC OG 300 2008 Directory of SRCC Certified Solar Water Heating System Ratings
14. Steady state on the solar storage tank can be achieved the same way as the auxiliary tank except for the lower half of the tank which does not posses an element To preheat the bottom of the tank the circulator pump is turned on and 1500 W is hardwired to the STCS from the control software 40 and the STCS is allowed to operate until the thermocouple inside the bottom of the tank reads the appropriate temperature of 57 2 C y Figure 19 Auxiliary element thermostat set point 52 C The system will take approximately two hours to reach a steady state temperature of 57 2 C Exact temperatures are not critical for this portion of the test because a uniform temperature distribution in this range cannot be determined due to thermostatic control limits and tank stratification However care should be taken to achieve 57 C to maintain consistency in testing conditions Once the system has reached steady state conditions return each analog power meter to the zero position of 12 o clock by adjusting the appropriate knob on the back of the timer Ambient system environmental conditions are also specified to be 19 7 C by the OG 300 section 7 3 displayed in Table 1 The temperature in the lab has been adjusted by Baylor University Facilities Department to approximately 19 C The weather and collector specifications can now be input to the LabVIEW user interface following the detailed instructions found in Appendix A Once the input
15. and outlet temperatures as well as flow rates from the STCS Power and element activation codes are then calculated and sent to the STCS Important data such as inlet and outlet temperatures flow rates power and any warnings are written to separate text files with time stamps for later reduction and analysis Accurate timing of the loops is a crucial requirement in order to obtain results that replicate the behavior of an actual home system throughout the day The producer loop timers control iterations 73 once per hour while the consumer loop timers controlled iterations once every thirty seconds The control software has two separate stop sequences that are implemented The first is an automatic stop that halts the iteration of the loops when the time period under analysis is complete A manual stop has been programmed to send a UDP packet to the STCS containing a zero power code thus eliminating power from the electric elements A disadvantage of using UDP to communicate with the STCS is that occasionally a packet will be dropped This situation must be accounted for so a consistent set of data can be collected The solution implemented in the code is a case structure with a local variable in one case that saves the previous value If the received data packet is empty then the previous value is passed otherwise the received value is used Calibrating the calculated power output to the power delivered by the STCS was necessary due to a l
16. extracting a known amount of energy from the system in the form of drawing hot water When constructing a schedule for energy drawn from a system several factors need to be considered including daily volume timing flow rate and variability Previous studies have shown that variability and flow rate are not of concern due to the volume of hot water drawn being the most significant variable Burch and Hendron 9 When volume and timing are the most influential variables determining the energy required by the system a simple hourly draw schedule is 11 appropriate Solar thermal systems are affected mostly by the timing and volume of the draws due to the availability of insolation and storage dynamics The SRCC specifies six draws to be taken beginning at 9 30 am solar time each approximately 7 217 kJ The draw schedule can be found in Chapter 3 and is based on the Gas Appliance Manufacturer Association s Consumers Directory of Certified Efficiency Ratings for Residential Heating and Water Heating Equipment ASHRAE 10 The test conditions can be found in Table 1 and are guidelines for a standard operating environment and energy draws Table 1 SRCC OG 300 rating conditions sec 7 3 11 Test Condition Criteria Environmental Temperature 19 7 C Auxiliary Set Temperature 57 2 C Water Mains Temperature 14 4 C Draw Type Energy Total Energy Draw 43 302 MJ Approximate Total Draw Volume 64 3 gallons Draw Rate 3 0 gpm N
17. flowrate correction factor The SRCC has tested each collector at a certain flowrate however in most test situations that is not the flowrate used Mass Flow Rate tested Mass Flow Rate used Working Fluid r Collector Area FrUL_test number 84 Q Ac_use Gt kta Frta_test r i Ac_use FrUL_test Ti Ta a gt pears gt Ke o o i The mass Flow rate tested and used has units of kg s The specific heat of the working fluid is in units of kor The collector area is defined in terms of m 2 The number of collectors in series is unitless FrUL_test is defined with units of Xxxx The Flow rate correction is unitless orking Fluid float32 FUL FUL m_test CpyAc ln 1 Frul_test 4c m_test Cp Im_test Float32 r r m_use Cpi Ac_use FULI 1 exp f Ac_use FUL m_use Cpyyyi t m_test Cp Ac_test FUL 1 expt Ac_test FUL Write_Power vi This VI writes the Useful power with a time stamp to an external file Power E C Documents and Settingsicemo DELL260_T DesktopiLyipower txt open or create 85 Useful Energy vi This VI integrates the useful power to MJ Power kan Total Energy Gain Summation otal Energy Gain See KS Total Useful Energy From the collector E MIJ KXXXIIs 305 1x10e 06MI I UDPTi_listen SubV1 vi This VI listens for the data packet sent by the STCS It checks to see if there is an error and if so sends a no power signal to
18. is calculated based on an average amount of insolation measured at the midpoint of the previous solar hour and provided in the OG 300 profile Thermal Collector loop test 2 11 09 OG300 vi Front Panel AER teres ist Jun Ch Waezurg STOP Figure A 3 Lower LabVIEW results panel 70 From hourly insolation the user can determine when the sunniest part of the day is and if it is economical to run the pump for that day The Power vs Time graph shows the actual power output from the collector array throughout the day and is critical for estimating the energy that will be available from the system Total Energy Gain is simply the power integrated and converted to kilowatt hours and represents the total amount of energy that was input to the stored water by the thermal collector At the bottom of the Results panel is a warning box and a manual stop control If the STCS encounters an error such as a leak or over temperature warning the user has the option of shutting down the test from LabVIEW rather than the electrical disconnects Block Diagram The block diagram contains the VIs that function as the controls of the system A flow chart describing the operation can be found in Figure A 4 The main goal of the controls is to accurately time two interdependent loops and communicate between them and an external source The basic strategy taken with the code is based on a producer consumer design where the first loop will i
19. less dependent on the energy consumed by each component and is influenced solely by the Solar Energy Factor as seen in Equation 5 from Chapter 1 Beet EE 5 SEF The Solar Fraction determined by the SRCC is 0 82 meaning 82 of the energy necessary in maintaining hot water is provided by the sun Table 8 shows the 51 Solar Fraction s for the two single tank tests which is very close to the SRCC s data This is because the SF is not as sensitive to external components as the SEF is Table 8 Solar Fraction for single tank tests and SRCC data Test SF Difference SRCC_ 0 82 Test 0 81 1 1 Test2 0 79 3 4 Avg 0 80 2 4 The SF can be used to calculate the total amount of energy provided by insolation using Equation 7 Oo SRT O y 7 The energy used by a standard conventional electric auxiliary tank Qeon is assumed by the SRCC to be 47 865 kJ day 16 The Solene single tank configuration is estimated to provide approximately 38 770 kJ day or 10 8 kWh of thermal energy to the stored water This quantity can be used in economic analysis to estimate the savings a solar thermal system will provide in comparison to a conventional system Assuming an average utility rate of 0 13 kWh the single tank system is estimated to provide 500 in annual savings Solar Storage Tank Behavior The behavior of the solar storage tank was closely monitored in order to better understand the temperature profile of the storage
20. specify that a draw has occurred for simplified data reduction According to the SRCC OG 300 solar profile insolation does not begin until 8 00 am solar time at this point the pump must be turned on to begin recording parasitic energy as well as avoiding stagnation within the STCS heating chambers and potential damage to the system During solar night there will be no insolation available and thus no power calculated so the pump can be turned off 43 The schedule in Table 4 defines the times that each draw and recharging cycle of the solar storage tank should occur The solar profile contains 15 hours of solar night which account for stand by losses in the tanks and auxiliary element usage Table 4 Standard weather profile draw schedule solar time Time Procedure 12 00 8 00 am Solar night beginning of test 8 9 30 am Insolation begins pumps activated 9 30 am 1 Draw 9 35 10 30 am Solar tank charge 10 30 am 2 Draw 10 35 11 30 am Solar tank charge 11 30 am 3 Draw 11 35 12 30 am Solar tank charge 12 30 pm 4 Draw 12 35 1 30 pm Solar tank charge 1 30 pm 5 Draw 1 35 pm 2 30 pm Solar tank charge 2 30 pm 6 Draw 2 35 5 00 pm Solar tank charge end of insolation pumps deactivated 5 00 pm 12 00 am Solar night end of test Energy Draw Procedure 1 From the LabVIEW timer ensure that the first draw begins at 9 30 am solar time 2 First open the mains to the indicated valve stop then adju
21. time the element operated A single tank system will quantify the amount of time the heating element on the solar storage tank is energized while a double tank system will measure the time energized for both heating elements on the auxiliary tank Finally Qpar is the amount of energy provided to external parasitic devices in the system such as pumps and controllers which is defined by CPs 4 The power to each parasitic load Ppar is multiplied by the period of time that each component is energized Equations 3 and 4 are only valid for external devices that require Ppar and Paux to be constant The Solar Fraction SF which is the portion of the water heating load provided by solar energy is defined in Equation 5 and ranges from 0 for a conventional gas or electric hot water heater to 1 for a completely solar thermal system with no auxiliary input Most systems have a solar fraction of about 0 55 to 0 7 which corresponds to a SEF of 2 to 3 respectively E 5 SEF The SRCC defines the Energy Factor EF for conventional electric auxiliary tanks as 0 9 GAMA 8 The Solar Fraction can also be used to determine the potential amount of energy saved by using solar energy versus conventional energy such as electricity or natural gas The Solar Fraction and Solar Energy Factor are non dimensional parameters that can be used to compare systems regardless of storage capacity or collector area This is important to ensure correct pairing of s
22. 0 Time from start of test hr Figure 24 Upper and lower tank temperature profiles for the solar storage tank in a double tank test The solar storage tank is allowed to reach steady state conditions however the element is disabled and the only source of energy input is the useful output from the STCS This is evident near hour eight in Figure 24 where an increase in temperature 57 coincides with the beginning of insolation followed by a decrease in temperature during energy draws After the end of insolation energy is no longer input to the solar tank and it is allowed to diffuse until the end of the test to approximately 43 C The auxiliary tank becomes the main storage tank and maintains the system set point temperature throughout solar night Figure 25 contains the time temperature profile for the auxiliary tank during a 24 hour period It is important to note that the lower element of the tank is the main heat source and the upper only activates if a large amount of energy is necessary Figure 25 shows temperatures were maintained throughout the initial standby period until the beginning of the energy draws Solar Day Tank Temperature C 0 5 10 15 20 Time From Start hr Figure 25 Time vs Temperature profile for the auxiliary tank during a double tank test Hour 10 shows activation of the element after the first draw compensating for the addition of 11 gallons of cooler water The element a
23. 4800 Parasitic energy usage for a single tank test Auxiliary Energy The auxiliary energy is calculated from five independent measurements of the auxiliary element power during a single tank test 3038 3044 S 3032 a i 3040 Paux z gt P 3 039x 10 W 3040 i 0 3040 taux 18305 Auxiliary element was activated for 45 min during a single tank test Qaux Paux taux The energy consumed by the auxiliary element Delivered Energy V 11gal Single draw volume Inlet and outlet temperatures were measured once every thirty seconds of the period ofa draw Data from one draw can be found below 95 15 1 55 5 40 4 14 4 56 5 42 1 usl fa e Ee AT fam K 42 7 14 1 56 3 42 2 14 0 55 8 41 8 14 2 55 7 41 5 In order to calculate the delivered energy the temperature differences over one draw averaged 7 1 AT avg 5 gt 47 42K i 0 The energy delivered during one draw is found to be J kg Cp 4184 p 1000 kg K 3 m 6 Qdel1 p V Cp AT avg Qdel1 7 317x 10 J The Energy delivered to the hot water load during each of the six draws are as follos 6973010 6814580 6416130 7701380 7790920 7382430 Qdraw The total energy delivered is the sum of the six energy draws 5 7 4308x 10 J Huel gt Qdraw i 0 96 The Solar Energy Factor can now be calculated Gant Gar The Solar Fraction can also be easily calculated EF 0 9 EF SF 1 SEF 97
24. 945 1 175 squeezed to hold it in place 1 8 to 1 4 Maximum Diameter u H P a ian lop 4 fa COn Crimp Ring Maximum Diameter 0 595 0 715 0 960 1 190 Spacing Variation in ring diameter out of round should not exceed 0 006 117 Zurn PEN Plumbing Installation Guide Crimp Systems continued Using The Zurn Go No Go Gauge After making a crimp connection use the appropriate opening of Go and No Go Openings No this flat Go No Go Gauge to check your finished crimp The Go opening should go freely across a crimped ring anywhere on its diameter with the possible exception of the upset area on the ring surface caused by the tool jaws closing Do not force the gauge across the ring The No Go opening should not go across a crimped ring anywhere If the crimp fails either test cut out the fitting and replace DO Always place the gauge opening on the Be certain to use the gauge opening sized We recommend you check every finished crimp ring at a 90 angle for an accurate for the diameter of your tube crimp with this gauge check DO NOT Do not slide the gauge onto the connection Do not try to save time by recrimping a crimp Do not modify the gauge opening for any Push It directly onto the crimp ring that does not gauge properly The fitting must reason They have been carefully manu be cut out and replaced factured to 002 inch tolerance 118 Zurn PEX Plumbing Installation Gui
25. ABSTRACT Design and Validation of a Solar Domestic Hot Water Heating Simulator Thomas A Cemo M S M E Mentor Kenneth W Van Treuren D Phil A growing demand for emerging alternative energy technologies is fueled by rising energy prices and decreasing energy supplies Domestic hot water heating is an industry that continues to benefit from increased research in and improvement of solar technology This thesis outlines the implementation of a solar domestic water heating simulator and the validation of a double and single tank domestic hot water configuration The results and procedures were compared to the guidelines of the Solar Rating and Certification Corporation s SRCC OG 300 standards The Solar Energy Factor for a double tank system was found to be 2 64 0 043 and for a single tank system 4 46 0 06 which is 12 and 9 respectively below data reported by the SRCC for a comparable test These tests will verify the performance of this solar water heating system and provide a baseline profile for further modifications to improve the efficiency of future solar domestic hot water heating systems Design and Validation of a Solar Domestic Hot Water Heating Simulator by Thomas A Cemo B S A Thesis Approved by the Department of Mechanical Engineering William Jordan Ph D Chairperson Submitted to the Graduate Faculty of Baylor University in Partial Fulfillment of the Requirements for the Degree of Master of Science
26. APPENDIX E Equipment Manuals Automated Valve Manual Override APPENDIX F Mains Chiller Mains Chiller Drawings Mains Chiller Controls Programming the controls Troubleshooting Performance Prediction Calculations BIBLIOGRAPHY 53 59 61 61 61 62 64 65 65 65 71 76 76 95 95 95 98 98 99 103 107 107 122 123 123 123 124 126 127 128 133 LIST OF FIGURES Figure 1 Solar Thermal Collector Simulator at Baylor University Figure 2 Active solar domestic hot water heating configuration Figure 3 Single tank configuration Figure 4 Double tank configuration Figure 5 System apparatus overview Figure 6 Components of incident radiation on a tilted surface Figure 7 Cross section of a general flat plate thermal collector Figure 8 Solar Thermal Collector Simulator assembly 5 Figure 9 STCS control circuit with temperature sensors Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Solar Domestic Hot Water Heater Simulator Closed circulator loop assembly Mains chiller assembly Analog power meters Filling procedure diagram Mains chiller tank and valve assembly Sequential draw valve procedure Single tank wiring diagram Double tank wiring configuration Auxiliary element thermostat set point Solene SLCR80DC 80DB single tank drainback system 16 Time vs Temperature pr
27. Factor which describes the ratio of energy delivered for a domestic hot water load to the external energy contribution of the system Typical values range from 2 to 5 depending on the working fluid used total collector area and configuration Systems that have extremely large SEF ratings greater than 10 are usually accompanied with large collector areas The Solar Energy Factor is defined by Equation 1 SEF Lu 1 O ux t Q par where Qaei is the energy delivered to the hot water load derived from integrating the test data from Equation 2 over the period of an energy draw lasting approximately four minutes Qae MCpAT 2 The test procedure outlined in Chapter 3 specifies energy to be drawn six times from the system over a 24 hour period simulating domestic hot water usage The total energy delivered is the result of an energy balance of the heat added to the system The heat can be calculated from the product of m the mass of water extracted during a draw Cp is the specific heat of water and AT is the temperature difference between the average steady state inlet temperature from the mains and system outlet The energy collected over each of the six draws is then summed to provide the total energy delivered to the hot water load The daily amount of energy provided to the auxiliary heating elements Qaux 1S defined by Equation 3 Bee 3 where Paux is the power delivered to the auxiliary element multiplied by the period of
28. Parts Warranty Brass drain valve e Cold water inlet brings cold water to tank Choice of two models storage tank or bottom to prevent mixing with heated water single element water heater specifically Anode rod equalizes aggressive water action e engineered for installation with residential for prolonged tank life indirect solar systems Cold water inlet hot water outlet relief valve Temperature and pressure relief valve included and anode rod at top of tank for easy access e Collector feed and return fittings located at and fast economical installation front of tank for convenient installation e Automatic temperature control DI e Isolated tank design for better heat Over temperature protector retention e High efficiency heating element See Residential Warranty Information Brochure e Rheemglas tank lining resists corrosion and EENEG a E prolongs tank life e Heat exchanger copper tubing wrapped around and secured to the tank Ou G Double wall vented design for positive leak detection gama DESCRIPTION ROUGHING IN DIMENSIONS SHOWN IN INCHES ENERGY INFORMATION ELEMENT APPROX WATTAGE SHIP WT MODEL NUMBER UPPER LBS 81V80HE 1 4500 W 81V80HE T Storage only 82V120HE 1 4500 W 82V120HE T Storage only R 17 3 Heaters furnished with standard 240 volt AC single phase non simultaneous wiring and 4500 watt heating element If heating elements of different wattages than those
29. T n Es asal FRONT VIEW Field Mount amp Pare Mount General Compatibility Signet Flow Sensors w freq out Enclosure Rating NEMA 4X P65 front Case PBT Panel case gasket Neoprene Window Polyurethane coated polycarbonate Keypad Sealed 4 key silicone rubber Weight Approx 325g 12 az Display Alphanumeric 2x 16 LCD Update rate 1 second Contrast User selected 5 levels Display accuracy 40 5 of reading 25 C Thermal sensitivity shift 0 005 of reading per C Electrical Power 12 to24 VDC 10 regulated 61 mA max current Sensor Input Range 0 5to 1500 Hz Sensor power 2 wire 15 mA 5VDC 1 3 or 4 wire 20 mA 5 VDC 1 Optically isolated from current loop Short circuit protected 120 English Contents 1 Specifications 2 Installation 3 Electrical Connections 4 Menu Functions IT T km eeng E SIDE VIEW SIDE VIEW Fidd Mount w Fidd Mant w 8050 Universal baso DOE E Current output 4to 20 mA isolated fully adjustable and reversible Maxloopimpedance 509 max 12V 325 N max 18V 600 N max 24 V Update rate 100 ms Accuracy 0 03mA Open collector output optically isolated 50 mAmax sink 30 VDC maximum pull up voltage Programmable for High or Low setpoint with adjustable hysteresis Pulse operation max rate 300 pulses min Environmental Operating temperature 10 to 70 C 14 to 158 F Storage temperature 15 to 80 C 5t
30. This is a sufficient process for theoretical performance however for actual performance location specific data is necessary The Solar Thermal Collector Simulator STCS Figure 1 constructed by Bolton 5 at Baylor University simulates repeatable collector performance and can be integrated into a domestic hot water configuration to simulate a complete residential system Figure 1 Solar Thermal Collector Simulator at Baylor University The STCS can be extremely useful for universities or research institutions wishing to conduct performance and efficiency research on solar domestic hot water systems By implementing a repeatable solar collector simulator new configurations and components of solar domestic hot water systems can be assembled and system performance can be evaluated The SRCC s main performance rating the Solar Energy Factor SEF compares the amount of energy the system can provide to the amount of energy necessary to maintain system temperatures An SEF rating of one indicates that the amount of solar thermal energy provided to the system is equal to the amount of non renewable energy used by the system SEF ratings greater than one indicate that the system will provide more thermal energy than the minimal auxiliary assistance of pumps and heaters resulting in higher efficiencies This rating can be used to compare different solar thermal systems including single and double tank configurations regardless of size or l
31. ack of resolution within the heating elements at low power levels At power levels less than 2300 W the STCS had difficulty distributing less than 20 of the maximum power over four elements A three step calibration process shown in Equation A2 was used in conjunction with activating a single element to accurately calculate the power delivered P 1 0647 P 533 02 P gt 2300W P 0 9704 P 109 64 150W lt P lt 2300W A2 P P P lt 150W 74 Where P is the calculated power and P is the calibrated power For the last two cases in Equation A2 only one element in the STCS is energized to account for the resolution of the elements operating range The data flow model utilized by LabVIEW greatly facilitated calculation of the parameters involved in determining insolation and power Many of the calculations necessary in determining the useful power were dependent on one other which made data flow logical Appendix B documents each VI utilized in the control software with a description and diagram 75 APPENDIX B LabVIEW Virtual Instrument Documentation Producer Loop Virtual Instruments OG 300 Reader vi Weather data Solar Time Start Hr Ambient Temperature Insolation Incidence Angle eather data f k et Eis LS e Ze Solar Time SCT em P Ambient Temperature SI ee Ambient Temperature gt tie G T RS 132 g 3 insolation gt Ka E gt Se Sc Insolation g mi Se ES gt Ea g S s BZ Inc
32. ame However it is a transient process since the hot inlet will always be changing making performance difficult to predict The heat rate of the system will be affected by the changing inlet temperature as well Time is the only variable that can be calculated however even it is an approximation based on the amount of tubing used During the extent of testing these predictions proved to be a good approximation of time required to chill the mains water 132 BIBLIOGRAPHY 1 Anderson D Grubb M Jonathan K 2002 Induced Technical Change in Energy and Environmental Modeling Annual Review of Energy and the Environment 27 pp 271 308 2 Energy Information Administration 2005 U S Household Electricity Report Regional Energy Profiles Online Available http www eia doe gov emeu reps enduse er01_us html 3 American Council for an Energy Efficient Economy 2007 Consumer Guide to Home Energy Savings Condensed Online Version Online Available http www aceee org consumerguide waterheating htm 4 Lane T 2004 Solar Hot Water Systems Lessons Learned 1977 to Today Energy Conservation Services of North Florida Inc pp 11 132 5 Bolton K Gravagne I 2009 Design of a Solar Thermal Collector Simulator Baylor University Waco TX 6 National Renewable Energy Laboratory 2003 United States Solar Atlas Online Available http mapserve2 nrel gov website L483NEWPVWATTS viewer htm 7
33. and Fluke digital thermometer were used bTe 2 2K Accuracies of respective instruments Dread 0 75K 2 Dk Fixed uncertainty of temperature measurement devices Bat zl br bread Inlet and outlet temperatures were measured once every thirty seconds of the period of a draw Data from one draw can be found below 100 15 1 59 9 40 4 14 4 56 5 42 1 14 3 56 8 42 5 14 57 1 K e SE e AT e o 42 7 14 1 56 3 422 14 0 55 8 41 8 14 2 SNI 41 5 Standard deviation for the sampled temperature differences oar 0 983 K Students t value for 8 samples and 7 degrees of A ege freedom Random uncertainty for temperature difference over one draw COAT Stay 0233 K Overall uncertainty for temperature measurements 1 2 2 2 SAT Bar Se STAT ar 2 336 K In order to calculate the delivered energy the temperature differences over one draw are averaged S 1 AT yg F gt AT 42K i 0 The energy delivered during one draw is found to be J kg Cp 4184 p 1000 kg K m 6 Qdell P V Cp AT avg Qdell 7 317 x 10 J The fixed uncertainty in the energy delievered during one draw can now be found 1 2 Bug IER SAT T pP Cp AT avg a 5 Bde 4 215 x 10 J 101 The random uncertainty for a set of six draws throughout a solar day can now be calculated 6973010 6814580 6416130 Qaraw 7701380 7790920 7382430 The standard deviation of the six dra
34. approximately 14 C In Figure 12 the mains are connected to an upper inlet port through which a gate valve controls the flow rate to the SDHW system The lower port contains the outlet for the chilled water and heat exchanger loop Each energy draw consists of approximately 11 gallons of heated water which must be replenished by the mains while simultaneously maintaining system pressure Over sizing the chiller tank provides three advantages a more consistent thermal mass of cool water to refill the storage tank less time required to chill the water for the next test and a higher resistance to temperature increase during mixing with the pressurized mains A K type thermocouple probe shown in Figure 12 was inserted into a thermowell to monitor the temperature of the bottom of the tank This will monitor the coldest region of the tank and also the initial thermal mass of water to enter the solar storage tank during energy draws 27 Gate Valve Chilling Tank j Circulator Pump Thermocouple Control Unit Isolation Valve gt z Ice Bath 7 1a Figure 12 Mains Chiller Assembly A Dwyer Love temperature control unit acts as a solid state relay with input from the thermocouple to restrict AC power to the pump when the set point is reached The Taco 003 circulator pump is capable of 0 5 gpm with a range of 0 5 feet of head Water is circulated through the bottom of the tank into an insulated ice bath containing a
35. asitic Time Auxiliary Time kJ hr kJ hr Test 1 3564 7 4 13 732 1 25 Test 2 3456 7 19 11 767 1 1 The Solar Fraction specified by the SRCC for this system is 0 70 implying 70 of the energy needed to maintain system temperatures is provided by solar energy Table 11 shows the Solar Fraction for each of the two double tank tests Table 11 Solar Fraction for a double tank test Test SF Difference SRCC 0 70 Test1 0 63 9 8 Test2 0 68 2 5 Avg 0 65 64 The values in Table 11 are slightly lower than manufacturer s data due to the extended operation time for the auxiliary elements After calculating the energy provided by solar sources from Equation 7 the double tank system can be estimated 56 to save 30 155 kJ day or approximately 8 3 kWh Assuming an average utility cost of 0 13 kWhr this system will provide an approximate savings of 388 per year Solar Storage and Auxiliary Tank Behavior In the double tank configuration the temperatures of the solar storage tank and the auxiliary tank were monitored to investigate the storage dynamics of both tanks working together The auxiliary tank is measured only with two surface mounted K type thermocouples at the upper and lower thermostats Figure 23 shows the time temperature profile for the solar storage tank incorporated into the double tank configuration A Tlow in s Ttop suf Tank Temps C 0 5 10 15 2
36. ater drawn can be adjusted 39 throughout the test by monitoring the Omega flow totalizer to allow a greater volume of water to exit in order to achieve the desired net energy After filling the circulator loop storage tanks and respectively wiring the system several initial measurements must be made before the testing can begin During testing the elements on the storage tanks will be energized and the power they receive must be measured in order to calculate the Qaux term of the SEF To do this each respective element is turned on with the thermostat set to approximately 57 2 C and the power is measured using an Amprobe 41PQ power meter This procedure is performed on the single element of the main storage tank or both elements of the auxiliary tank during the preheating period In normal operation of a water heater the system must reach the system set point temperature in order to provide enough hot water to the load and simulate preheating from the previous solar day A steady state temperature of 57 2 C 2 8 C specified by SRCC OG 300 section 7 3 will be the initial set point for this experiment Set the thermostat on the respective tank to the approximate location of 57 2 C The resolution on commercial hot water heaters is very poor and an approximation shown in Figure 19 is used as the set point of 57 2 C The temperature on the upper and lower portion of the auxiliary tank can be monitored using surface mounted thermocouples
37. ation Ibn Idif ollector Slope float32 It It Ibn cosT Id 1 cos B 2 Ipa 1 cos B 2 otal Insolation ba The Total Insolation has units of Wim 2 Insolation Integrator vi This VI integrates Wh m 2 to MJ m 2 It is mainly for qualitative purposes Total Hourly Insolation fion cece Tot Available Insolation otal Hourly Insolation ot Available Insolation Let MJjm z x4 whi m 2 3600 wh 1x10e 06M3 J 82 Consumer Loop Virtual Instruments efficiency vi The instantaneous efficiency is the ratio of useful power delivered to the system to the available insolation Collector Data moe Efficiency Instantaneous Efficienc DBL Float32 n n Frta Kta FruL Ti Ta ollector Data Power SubVI vi This VI calculates the useful power that is delivered by the system Mass Flow Rate tested Collector Area number Collector Data Mass Flow Rate used Working Fluid Power 83 The mass Flow rate tested and used has units of kg s ss Flow Rate tested The specific heat of the working fluid is in units of Jet a The collector area is defined in terms of m 2 The number of collectors in series is unitless SEET Power is thus calculated in Watts ass Flow Rate used D orking Fluid L ollector Area 5 z umber H es fp ollector a GH e i T flowratecorrect vi This VI calculates the
38. c Dr Gravagne s vision for this project and thorough understanding of solar hot water heating has been invaluable in achieving such successful results I would also like to thank Dr Bill Jordan and the Mechanical Engineering Department at Baylor University for providing the means and resources to participate in such valuable research I extend a great deal of thanks to Mr Ashley Orr for his assistance and guidance in the assembly of the testing apparatus I would also like to thank him for his patience during the countless trips to Lowe s for the seemingly endless design changes Mr Dan Hromadka has been a great deal of help with troubleshooting many of the computer problems associated with the project and I would like to thank him for his patience and assistance I would also like to extend thanks to Dr Stephen McClain for his assistance in designing the heat exchanger and his expertise on the details of temperature and flow control that I did not learn in my undergraduate degree I would like to thank Kirk Bolton for his collaboration with me and the many hours put into the early development stages of this project John Miller deserves a great deal of gratitude for his patience and assistance with many of the electrical components of the system I would also like to thank Brett Perlowski and Aramark for their generous contribution of the massive amount of ice used in this project Finally and most importantly I would like to extend a
39. cision is required when rotating the shaft so as not to restrict flow or damage the motor gears 3 Once the drive shaft has been rotated replace the visual indicator to the appropriate position and retighten the screw 122 APPENDIX F Mains Chiller Mains Chiller Drawings Auxiliary port Taco 003 pump an Outlet to system E Thermocouple probe Love Controls ii d vi Heat exchanger R i in ice bath a L 1 d M Di Il WU If ji dl Jil ji lj Hi i Figure F 1 Mains chiller sketch and operation 123 Mains Chiller Controls The 1600 series Love controls are a microprocessor based temperature process control unit Figure F 2 is a basic diagram for the different options of temperature measurement available INPUTS ZS a P D gt A ZS Current or D CO gt H Voltage Output A ALARM OUTPUT Terminals 4 amp 5 are Output Normally Open See 8 Rating Label F1 3 8 A 250 VAC Medium Lag Line Input See Rating Label for details Figure F 2 Love controls wiring diagram The current set up requires power to be wired to terminals 13 and 14 and a jumper from terminal 14 to output terminal 8 Output terminal 7 terminates with the white wire on the pump The yellow wire of the pump is then wired terminal 13 The ground wires are spliced together and run directly to the pump Figure F 3 is a guide for the front display of the control unit T
40. ck to the system set point temperature 53 Double Tank Test Results The double tank analysis is similar to a Solene SLCR80DC 80DB XE drainback system shown in Figure 23 using water as the working fluid 16 M l U l U l 1 Lech i R OF Cold S sold Su Solor Tank Existing Woter Meoter w Figure 23 Solene SLCR80DC 80DB XE double tank drainback system 16 This system was also subject to the solar profile set forth by the SRCC found in Appendix E and test conditions as the single tank test The SRCC system rating sheet can be found in Appendix E The Solene XE system consists of the same components as the single tank configuration with the addition of a conventional 50 gallon hot water heater with two elements The current system tested in this experiment has 10 fewer gallons of storage however this difference is assumed to be negligible because the same amount of energy is extracted from the system regardless 54 of size Although the Solene system is maintaining 10 extra gallons of water from an energy balance approach the difference in standby losses between a 40 gallon tank and a 50 gallon tank is 16 Watts Many commercially available double tank systems are retrofits to existing conventional hot water heaters and the auxiliary tank size may vary The increased volume in the Solene configuration will provide a higher heat capacity to the system however it is also accompanied by a slower response to a
41. continuous temperature distribution throughout the collector All of the pipes within the system are insulated and assumed to have negligible temperature loss Domestic collector configurations commonly do not have any solar tracking controls so a fixed orientation facing due south with a tilt of 40 degrees is determined by the SRCC document RM 1 Methodology for Determining the Thermal Rating of Thermal Collectors 12 The pump on the closed circulator loop is a constant speed impeller driven pump By fixing the flow rate a constant speed pump simplifies initial testing and eliminates the need to control and correct for different flow rates throughout the system Beckman and Duffie 13 The initial flow rate of 3 75 gpm within the closed loop causes residences time within the STCS to be limited and thus reduce the amount of energy delivered to the water In an actual collector array higher flow rates are acceptable because instantaneous efficiency is dependent on the surface temperature of the collector and thus higher flow rates will increase the heat transfer rate from the collector to the working fluid Beckman and Duffie 13 In most active systems a controller operates the initiation of the pump by comparing the temperature on the bottom of the solar storage tank to the outlet of the collector If there is a significant temperature differential then energy can be gained and the pump is activated The current system does not contain a c
42. curacy of Kill A Watt power meter as percentage of reading Qpar 4392000J Sampled parasitic energy usage for a single tank test par Ppar Qpar Fixed uncertainty for parasitic Snar 8 784x 10 J energy use P Auxiliary Energy Random Uncertainty taken from five independent measurements of the auxiliary element power during a single tank test 2979 2977 2973 2971 Pg 2972 2969 ale 4 gt A P 2 479x Iw i 0 Student s t value at 95 confidence for 5 samples t 2 1318 and 4 degrees of freedom Standard deviation of power measurements Gp 3 78W The random uncertainty for the five power measurements is thus found to be Op Stpaux SS 1 612W The fixed uncertainty is the accuracy of the Amprobe power meter Sp 0 1W Thus it follows that the uncertainty for auxiliary power is found to be Ze 2 P E y Sigs 1 615W 99 The accuracy of analog power meters is found to be one second 5 Is taux 132 Auxiliary element was activated for 45 min during a single tank test Qian Pauw ane The energy consumed by the auxiliary element The overall uncertainty of the delivered energy can now be found to be 2 2 2 Saux taux Lac 3 Saux 3 269x 10 J Delivered Energy by 0 015 Accuracy of Omega Totalizer as percentage of reading V 11gal Single draw volume by by V y 6 246 10 Lu Fixed uncertainty for draw volume When measuring temperatures a K type thermocouple
43. d the value from the SRCC Table 6 SEF test values compared to SRCC values for a single tank test Test SEF Difference SRCC 4 9 Test 1 4 67 4 7 Test2 4 25 13 3 Avg 446 9 50 The data in Table 6 conveys that the system is capable of producing repeatable results that are accurate within laboratory expectations The SEF from the first single tank test was 4 7 below the SRCC value due to the auxiliary element being active for approximately four minutes longer than on equivalent SRCC tests The second laboratory test was slightly higher on auxiliary element activation time by 30 or 8 minutes however the pump correction factor lowered the time the pump operated by 14 to 7 hours and 40 minutes from a constant 9 hours increasing the calculated SEF The pump correction factor only modified the time the pump was on in the first test by 1 hour and 25 minutes or 14 Table 7 displays the values of the auxiliary and parasitic energy consumed and the respective time each one was active Table 7 Parasitic and auxiliary energy loads and time active for a single tank test Test Parasitic Time Auxiliary Time kJ hr kJ hr Test 1 3664 7 6 5561 0 5 Test 2 3672 7 7 6338 0 57 Both of the tests showed that the results from parasitic auxiliary and delivered energies are repeatable for the given system configuration and solar profile The Solar Fraction which is the portion of energy provided by solar sources is much
44. dded energy The average Solar Energy Factor for a double tank test is 2 64 which is 12 below the rating provided by the SRCC of 3 0 This means the system will provide the same amount of hot water for one third of the electric energy cost that a conventional system would Table 9 compares the SEF s of the two double tank tests with the SRCC data Table 9 SEF test values compared to SRCC data for a double tank test Test SEF Difference SRCC 3 0 Test 1 2 44 18 6 Test2 2 84 5 5 Avg 2 64 12 The first double tank test provided a SEF of 2 44 which was 18 6 less than the SRCC data due to extended element activation times During the element activation periods the temperature of the water estimated from the thermocouple at the top of the solar storage tank was less than 50 C After mixing and extraction of 11 gallons of hot water the auxiliary tank temperature dropped below the set point 55 and activated for a total of 75 minutes Due to the low resolution of 3 C on the thermostat additional element activation time may have accumulated during temperatures very near to the set point This data is displayed in Table 10 along with the parasitic energy consumed by the pumps The pumps were active with the pump correction factor for 7 hours and 25 minutes for the first test and 7 hours and 10 minutes for the second test Table 10 Parasitc and auxiliary energy loads for a double tank test Test Par
45. de Crimp Systems continued Adjusting The Medium Crimp Tool Note Zurn Crimp Tools are factory set to provide proper crimps This should be checked before use by making a test crimp con nection and checking it with the crimp gauge As long as the finished crimp connection gauges properly there Is no need to adjust the tool All crimp tools wear which increases the crimp diameter after many crimps When the crimps start to approach the maximum ring diameter adjust the back pin To adjust for a tighter crimp remove the E clip for example pop it off with a screwdriver and slide the back pin head out about 1 4 inch Warning The Adjustment Pin must not be pulled or pushed completely out Rotate the back pin until the line on the hex head points to the next highest number on the tool body push the pin back in and refit the E clip Five adjustments are available Pop off E clip For a tighter crimp turn mark on pin to the next number OOQ OOO Maintenance For easier better crimps and longer tool life keep tool clean and rust free inside and out Lubricate all moving parts frequently with light oil Adjusting The Large Crimp Tool Zurn Crimp Tools are factory set to provide proper crimps This should be checked before use by making a test crimp connection and checking it with the crimp gauge As long as the finished crimp connection gauges properly there is no need to adjust the tool 1 Loosen the bottom Locking
46. dynamics of a single tank system throughout a 24 hr period The lower internal tank temperature can be 52 accurately measured by the thermocouple shown in Figure 20 however the top of the tank is measured with a surface mounted thermocouple at the thermostat which is assumed to represent the temperature of the upper portion of the tank Temperatures were recorded throughout each test and a time temperature profile of the tank was created as shown in Figure 22 70 nD oN Solar Day Nn Nn RMN na Tlow in Ttop suf A Tank Temperatrues C w Lu O U Figure 22 Upper and Lower temperature profiles of the solar storage tank for a single tank test 10 15 Time from start of test hr 20 Initially for a test the tank is allowed to come to a steady state condition of approximately 57 2 C which is a function of the thermostat setting The first eight hours on the graph are solar night consisting of standby losses of about 1 2 C hr or 422 W From solar hours 8 to 15 the portion of the graph with a steeper slope represents the draw period of the solar day The temperature of the lower portion of the tank dips to below 40 C which is expected due to mixing of the inlet water from the mains After the final draw near hour 14 the temperature of the tank is the lowest and the element activates attempting to bring the stored water ba
47. e Taco 009 circulator pump will operate during the solar hours where insolation is available The Solar Energy Factor defines parasitic loads to be pumps and any other devices that require external power The energy consumed by these devices must be recorded and included in the calculation of Q from Equation 2 in Chapter 1 A P3 International Kill A Watt power meter is utilized for these readings 29 The Kill A Watt plugs into a standard110V wall outlet and any device requiring 110V and less than 15 A can be plugged directly into the meter A variety of measurements including voltage current power and frequency along with energy can also be read directly from the meter The display can be calibrated to measure energy in units of kilowatt hours kWh with an accuracy of 0 2 of the reading As long as the unit is energized it will meter a continuous reading Unplugging it will clear all previous data care must be taken with timing and operation to ensure accurate readings At the conclusion of the test the total energy consumed by the pump can be read from the display and recorded Analog Power Meters The auxiliary energy to each resistive heating element is a critical value that is necessary when calculating the solar energy factor A pair of analog clock timers has been developed to activate when the element receives current Each clock has been modified from operating on 110V to operating on 208 V by adding a bank of six 33kQ resist
48. e homeowner The sudden flooding of the market along with faulty products and cunning salesman created several purchasing obstacles including consumer ignorance poorly designed products and fraud The skilled and qualified professionals were overshadowed during the sudden growth of this deregulated technology In order to overcome these obstacles and promote a promising technology the solar thermal industry formed the Solar Ratings and Certification Corporation SRCC in 1980 The SRCC is an independent non profit organization that has developed efficiency ratings for consumers contractors manufacturers and governments to evaluate and compare the performance of domestic solar hot water heating components and systems The SRCC ratings provide consumers with confidence that the products they purchase are reliable and have been tested for efficiency They also provide manufacturers and contractors with credibility and a fair market by establishing standards by which to certify equipment Finally the SRCC ratings provide a standard for government to structure tax credits which are an incentive to encourage implementation of residential solar technology The SRCC determines efficiency ratings for solar domestic hot water systems by subjecting each component of the system to individual tests to determine key parameters Then using those results and standardized conditions as inputs to a computer simulation the whole system performance is modeled
49. e tank drainback system 16 49 The Solene system utilizes two Solene Chromagen SLCR 40 panels with a total panel area of 7 4 m The specifications for these collectors are input to the LabVIEW control software and can be found in Appendix E The solar storage tank is a Rheem 80 gallon Solaraide and the pump is a Taco 009 both of which are identical equipment to that used in this experiment The main differences are that the Solene system contains a differential temperature controller mixing valve drain back tank and piping losses associated with the collectors The absence of a differential temperature controller has the most impact on replicating the system s performance because it directly controls the amount of parasitic energy consumed and operating the pump for a constant nine hours throughout solar day is not realistic To account for this a pump correction factor was implemented during data reduction to turn the pump on when the temperature difference between the bottom of the solar tank and the outlet of the STCS was greater than 2 75 C Since the pump ran at a constant power level the time the pump was active was adjusted according to how many differential temperature readings met the controller criteria The average Solar Energy Factor for a single tank test was 4 46 which is 9 lower than the SRCC s rating of 4 9 for the Solene single tank system Table 6 shows the Solar Energy Factor s of the two tests an
50. ea foa feo f wD fis 5030 lt e Cold Su Solor Tank Existing Woter Meoter DS 0G300 System Reference 2006030C November 2008 Certification must be renewed annually For current status contact SOLAR RATING amp CERTIFICATION CORPORATION c o FSEC 1679 Clearlake Road e Cocoa FL 32922 e 321 638 1537 Fax 321 638 1010 108 SOLAR WATER HEATING SYSTEMS CERTIFICATION AND SYSTEM NAME SYSTEM TYPE SRCC OG 300 Solene Solene Chromagen Drain Back CERTIFIED SOLAR WATER HEATING SYSTEM SUPPLIER Solene 927 Fern Street Suite 1500 Altamont Springs FL 32701 407 831 1941 407 831 1208 Fax Solene Chromagen Drain Back Indirect Forced Circulation Description Glazed Flat Plate Collector Differential Controller Tank Wrap Around Heat Exchanger with a Double Wall and Positive Leak Detection No Load Side Heat Exchanger Fluid Class I Freeze Tolerance 23 3 C 10 F Electric Auxiliary Tank System Model Name Cert 300 4 CertDate Collector Panel Collector Panel Name Total Total Solar Solar Aux Aux SEF Manufacturer Panel Panel Tank Tank Tank Tank Area Area Vol Vol Vol Vol Sq m Sq ft _ M aD O gal SLCR60DC 80DB 2006001E 3 15 2006 _ _Solene SLCR 30 5 6 60 6 303 80 29 SLCR80DC 80DB 2006001D 3 15 2006 Solene SLCR64DC 120DB 2006001F Solene SLCR 32 5 9 640 454 120 25 SLCR64DC 80DB 2006001C Solene SLCR 32 59 640 La 80 30 SLCR80DC 120DB 2006001G Solene SLCR 40 74
51. en powered by non renewable energy sources Solar thermal systems have the ability to utilize seemingly inexhaustible supply of solar radiation to deliver efficient thermal energy to the home Increasing efficiency of appliances space and water heating by using solar energy is a simple and effective way to conserve energy and reduce the load felt by the producer The purpose of this study is to design a simulation facility that can accurately produce repeatable performance for a domestic solar hot water heating system The thermal efficiency ratings for a single and double tank configuration will be validated against computer simulation data from the Solar Rating and Certification Corporation Domestic hot water heating is an industry that has been slowly taking advantage of solar technologies over the past 25 years In the late 1970s during the Arab oil embargo a 50 federal energy tax rebate was issued that prompted thousands of manufacturers and contractors to install solar thermal systems However many of the original designs were flawed and malfunctioned frequently with a tendency to consume more energy than their rated savings Lane 4 Installation problems such as roof damage and leaks also heavily contributed to consumer distrust of the industry A lack of serious research coupled with immediate implementation of this technology fostered a period of learning by doing that resulted in many unsuccessful designs at the expense of th
52. enu items will be reset LPbr Loop break SEnC Sensor rate of change ALIH Alarm inhibit OPEn InP Open input error message ArEA Area error message bAd InP Bad input error message CHEC CAL Check calibration error message Correct the problems associated with the above conditions first before using these reset keys More than one error could be present Caution is advised since several items are reset at one time Figure F 3 Love 1600 Series control panel function 125 Programming the controls Press Index and use the Up or Down arrows to program the set point temperature in C Press Enter to save the value Proceed to the Secure Menu by holding the Up and Enter buttons for 5 seconds Scroll through the menu by pressing Index change the setting using the Up or Down keys while saving the value using Enter The following table displays each menu and the setting for the mains chiller application For a detailed description see the user manual Table F 1 Secure menu program settings Program Setting Inp CA Unit C dPt 0 InpT Off SeNC 70 SCAL 179 SCAH 1371 SPL 10 SPH 45 SPlo OUTa S10t onof Sist dir SILP 0 on AL OFF Next proceed to the Secondary Menu by pressing the Up and Enter buttons once simultaneously Scroll through the menu by pressing ndex change the setting using the Up or Down keys while saving the value using Enter Table F 2 displays the settings for each program of the Secondary Menu for the
53. f radiation It is important to note that the solar profile provided by the SRCC contains a value for total insolation however the control software has the option of using specific weather data where the isotropic diffuse model is utilized Several designs of solar thermal collectors are currently available however the flat plate style was chosen as the collector under analysis because they are the simplest to model and most widely implemented in homes and businesses A flat plate collector shown in Figure 7 consists of copper tubing placed inside an insulated box that has a protective glass cover The useful output power from a collector is dependent on many quantities such as location insolation angle of incidence and flow rate The SRCC collector specification sheets estimate thermal performance for several given atmospheric conditions and temperature differences across the collector For the collector used in this analysis on a mildly cloudy day with an average temperature difference between the inlet and ambient temperatures the Solene Chromagen SLCR 40 is expected to output 39 MJ panel per day Flat Plate Collector Figure 7 Cross section of a general flat plate thermal collector 14 The SDHW system is assumed to be connected by high temperature piping in a way that equalizes the flow rate of the working fluid through the collector array This will simplify the flow rate and power calculations by ensuring consistent flow and a
54. f the auxiliary tank but it is disabled and manually overridden for switching configurations A detailed procedure to switch the orientation of the automated valve can be found in Appendix F A two tank system will use the solar storage tank to preheat the water and if necessary provide additional energy in the auxiliary tank to bring the water to the system set point temperature by energizing two 3300 W resistive heating elements The tanks are secured on insulated concrete bases with drain pans and have sloped drainage piping There are three K type thermocouples in the tank array that are connected to auxiliary ports on the STCS shown in Figure 9 The inlet from the mains solar storage tank temperature and the system outlet temperature are reported to the user once every thirty seconds so the SEF and SF may be calculated and a temperature profile of the system behavior may be monitored An Omega flow totalizer is installed on the system outlet at the auxiliary tank to monitor the volume of water drawn during each solar day 23 Circulator Pump An active system requires components that are externally powered such as pumps controllers and automatic valves For the closed circulator loop a 1 8 hp Taco 009 cartridge pump capable of 0 8 gpm and 0 34 feet of head was selected It is located at the base of the solar storage tank and will force water through the STCS and the heat exchanger on the closed loop as shown in Figure 11 The low p
55. gy a differential controller is suggested to control the main circulator pump on the heat exchanger loop Incorporating this unit to measure the difference between the outlet of the STCS and the bottom of the solar storage tank will better simulate actual performance and provide the actual activation time of the pump However care must be taken not to damage the STCS with the controller due to low temperature differences and high stagnation temperatures within the heat exchanger chambers The inlet outlet and tank temperatures are currently recorded manually from digital thermometers Automation of this system would allow greater convenience in testing and a better temperature profile of the tanks Since thermocouples output milli volts an Omega thermocouple transmitter in conjunction with a precision resistor can be incorporated to provide a 0 5 V signal that can be sampled by the STCS During several preliminary tests of the double tank system SEF values were found to be over 50 greater than the SRCC value It was determined that the cause of this was a thermostatic set point below 57 2 C This behavior leads to the suggestion that slightly lowering the set point on the thermostat can greatly improve water heating efficiency and ultimately save money For future tests greater thermostatic control would be desired to ensure accurate results 62 An array of thermocouples should also be constructed so that they can be inserted into the tank
56. he index up down and enter keys will progress the user through the menu and set the specified program The controls act as a solid state relay switching 110V AC power on and off to the Taco 003 circulator pump 124 FRONT PANEL KEY FUNCTIONS Set Point 1 Lam ___ Process Variable Alarm Lamp Set Point 2 Lamp Set Variable F Indicator C Indicator INDEX Pressing the INDEX key advances the display to the next menu item May also be used in conjunction with other keys as noted below UP ARROW Increments a value changes a menu item or selects the item to ON in the upper display DOWN ARROW Decrements a value changes a menu item or selects the item to OFF in the upper display ENTER Pressing ENTER stores the value or the item E NTE R changed If not pressed the previously stored value or item will i be retained UP ARROW amp ENTER Pressing these keys simultaneously brings up the secondary menu starting at the auto manual selection Pressing these keys for 5 seconds will bring up the secure menu INDEX amp DOWN ARROW Pressing these keys simultaneously will allow backing up one menu item or if at the first menu item they will cause the display to return to the primary menu If an alarm condition has occurred these keys may be used to reset the alarm INDEX amp ENTER Pressing these keys simultaneously and holding them for 5 seconds allows recovery from the various error messages The following m
57. heat exchanger consists of 60 ft of 0 5 in diameter copper tubing 28 and then back to the top of the tank to mix This cycle continues until the set point temperature is reached and the pump is shut off by the controller The chiller is isolated from the mains during operation by two valves on the inlet and outlet of the tank When a draw is initiated the isolation valves are opened and the mains pressure forces chilled water in the solar storage tank expelling an equal volume of hot water to the system outlet A single valve controlling the flow presents an over determined system where temperature will change as a function of flow rate Since an approximate temperature of 14 C is desired the water can be chilled below this point to account for mixing and any other increases in temperature The pump and heat exchanger are connected in parallel with the tank mains and SDHW system thus presenting resistance to flow and a possibility of back flow into the pump causing damage A check valve was placed after the pump to avoid this situation and force flow through the tank initially A small rotameter is placed before the inlet to the tank to indicate flow through the circulator pump After the second draw more ice will need to be added to the insulated container to maintain the ice bath near 0 C Detailed drawings wiring diagrams and calculations can be found in Appendix F regarding design of the mains chiller Kill a Watt Power Meters Th
58. idence Angle z wd Incidence Angle gt S SI Draw dert wf D Ti Total Sim Time raw Time 76 20 575 77 Nie gt i 9 Default ch 11 575 Declination SubVI vi The angular position of the sun at solar noon in radians Day of Year Pet Declination Declination has units of radians Tsol SubV1 vi Calculates the solar time based on the previous solar hour Depends on location and day of the year All insolation calculations are based on this time scale Lstd Lloc Tsol Current Hour Day of the Year 78 tandard Longitude deg Solar Time hr Local Longitude deg float32 E 229 2 0 000075 EN The Standard and Local Longitudes are calculated in degrees 0 014615 cas 2 B Solar Time has units of time in hours 0 04089 sin 2 B For certain calculations the perterbation constant may be zeroed out Hour angle SubVI vi Calculates the angle in radians from the solar time which describes the angular displacemnet of the sun with respect to the local meridian morning is negative Afternoon is positive Solar Time Hour angle Ss Hour angle has units of radians Incident Angle mod SubVI vi The ratio of transmittance absorptabce ta product at some angle to the transmittance absorptance product at normal incidence Incident Angle Modifier Kta Incidence Angle Incidence Angle Incident Angle Modifier a These calcua
59. idential and Light Commercial higher head lower Standard H Output Compact Des en ge i igh EEN EE flow water circulating applications Typical uses include Hydronic heating Radiant In Floor Panel Quiet Efficient Operation Direct Drive Low Power Consumption Unique Replaceable Cartridge Design Field Serviceable Self Lubricating e No Mechanical Seal Unmatched Reliability Maintenance Free Universal Flange to Flange Dimensions Cast Iron or Bronze Construction Materials of Construction Casing Volute Cast Iron or Bronze Stator Housing Aluminum Cartridge Stainless Steel Impeller Non Metallic Shaft Ceramic Bearings Carbon O Ring amp Gaskets EPDM Model Nomenclature F Cast Iron Flanged BF Bronze Flanged Variations Z Zoning Circulator J Bronze Cartridge with Cast Iron Casing Performance Data Flow Range 0 8 GPM Head Range 0 34 Feet Minimum Fluid Temperature 40 F 4 C Maximum Fluid Temperature 230 F 110 C Maximum Working Pressure 125 psi Connection Sizes 3 4 1 1 4 1 1 2 Flanged Wu FOR INDOOR USE ONLY heating and closed loop Solar heating systems The Bronze 009 can be used in higher head lower flow Heat Recovery open loop Solar heating and Light Commercial Domestic Water Recirculation systems The unique replaceable cartridge contains all of the moving partsand allows for easy service instead of replacing the entire circulator Compact
60. iency 6 is calculated from Equation A1 and describes the performance of the collector array at that moment in time However this value is not related to the system efficiency or the solar energy factor Al n Frraekta mam Gr Frta is the Y intercept and FrUL is the slope from the collector efficiency equation and kta is the incident angle modifier all three of which can be found on the SRCC collector specification sheet 7 is the inlet temperature to the collector and T4 is the ambient temperature of the environment from the weather data file Finally Gr is the total available insolation for that day for central Texas an average value would be 69 5 5 kWh m The inlet temperature of the collector is the most influential variable in determining instantaneous efficiency The bottom of the solar storage tank and the outlet of the auxiliary tank are also reported to the user 7 The lower portion of the results panel shown in Figure A 3 has graphical representations of the inlet and outlet temperatures on the STCS that are recorded for a temperature distribution throughout the day These values are written to separate text files and are available for further data reduction The mains inlet temperature is also recorded but should be a constant temperature due to the test conditions and the mains chiller The Total Insolation graph conveys the amount of radiation the collector receives for the specific hour of the day It
61. in Mechanical Engineering Approved by the Thesis Committee Kenneth W Van Treuren Ph D Chairperson Ian A Gravagne Ph D Larry L Lehr Ph D Accepted by the Graduate School May 2009 J Larry Lyon Ph D Dean Page bearing signatures is kept on file in the Graduate School Copyright 2009 Thomas A Cemo All rights reserved TABLE OF CONTENTS LIST OF FIGURES LIST OF TABLES LIST OF ABBREVIATIONS ACKNOWLEDGMENTS CHAPTER ONE Introduction Background Theory System Overview Key Assumptions Chapter Descriptions CHAPTER TWO System Apparatus Solar Thermal Collector Simulator STCS LabVIEW User Interface Storage Tanks Circulator Pump Expansion Tank Flow Meters Mains Chiller Kill a Watt Power Meters Analog Power Meters CHAPTER THREE Experimental Methods Closed Loop Filling Procedure Storage Tank Filling Procedure Single Tank System Wiring Diagram Double Tank Wiring Diagram Mains Chiller procedure Energy Draw Procedure CHAPTER FOUR Results Test Conditions Single Tank Test Results iii vii viii Double Tank Test Results Discussion CHAPTER FIVE Conclusions and Recommendations Conclusions Reccomendations APPENDICES APPENDIX A LabVIEW User Manual Front Panel Block Diagram APPENDIX B LabVIEW Virtual Instrument Documentation APPENDIX C Sample Calculations Single Tank Sample APPENDIX D Uncertainty Calculations Single Tank Uncertainty Double Tank Uncertainty
62. l power 45 CHAPTER FOUR Results The test plan devised for this experiment resulted in two tests each of a single and double tank configuration to show that the system can produce realistic and repeatable results In order to verify the results each respective system s performance was compared to solar designs that are commercially available from Solene The testing conditions were controlled within experimental limits according to Section 7 of the OG 300 document Test Conditions The environmental and procedural test conditions set forth by the SRCC are referenced to the U S Department of Energy s Test Procedure for Water Heaters 15 The SRCC leaves out several crucial details found in the OG 300 document including error limits on all of the specified conditions Table 5 outlines the current test conditions in the laboratory the SRCC specifications and the Department of Energy limits Table 5 Testing condition criteria Condition Baylor SRCC DOE Environmental Temperature SE 19 7 C 18 3 21 1 C Water Mains Temperature 14 5 C 14 4 C 14 4 C 1 1 C Auxiliary Set Temperature 57 2 C 3 C 57 2 C 57 2 C 2 8 C Approximate Total Draw Volume 68 2 gal 64 3 gal 64 3 gal Draw Rate 3 gpm 0 25gpm 3 gpm 3 gpm 0 25gpm Total Energy Draw 42 838 MJ 43 302 MJ NA 46 The ambient environmental temperature is difficult to control and must be monitored by facility management at Baylor University However this variable has
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64. le tank test vii 12 20 21 44 46 50 51 52 55 56 56 EF FruL Fro Gr Ip PEX Qiz Qaei Qpar SEF SF LIST OF ABBREVIATIONS Collector Slope Energy Factor Slope of Collector Linear Efficiency Equation Y Intercept of Collector Linear Efficiency Equation Total Daily Insolation Beam Radiation Current Diffuse Radiation Ground Reflected Radiation Hourly Insolation Incident Angle Modifier Instantaneous Efficiency Power delivered to STCS Calibrated Power delivered to STCS High Cross Linked Polyethylene Auxiliary Element Energy Energy Delivered to Hot Water Load Parasitic Energy Geometric Factor Solar Energy Factor Solar Fraction viii SDHW STCS SRCC TMY2 UDP VI Solar Domestic Hot Water Solar Thermal Collector Simulator Solar Rating and Certification Corporation Collector Inlet Temperature Dry Bulb Temperature Typical Meteorological Year Universal Datagram Protocol Voltage Virtual Instrument ACKNOWLEDGMENTS There are many people who have contributed to my success throughout the duration of this project and I could not have completed it without them I would first like to extend my deepest thanks to my advisors without which this project would have never been realized Dr Van Treuren has provided me with a superior education in my undergraduate and graduate career He has constantly supported me and guided me to maintain a strong work ethi
65. led is re circulated until it reaches a specific temperature The following procedure can be found in Incropera and Dewitt 19 Calculations The following are important constants and defined variables kg Cp 4184 Mot 0 1261 SS kg K d 0 425in 0 011 m u 0 00108 N m do 0 5in 0 013 m kg np iikee Thi 22 C m Pr 7 56 Tho 14 C 2 z TTA Te 0 G SES l mk 98 k 401 La S S S CU mK 1 ky20 m B 0 000006805 a 1 429 x 107 7 K p Cp s o 3 v 19gal 0 072 m m v 0 000001788 S 128 The energy required to lower the temperature of 19 gallons of water 8 deg C is found by sing an energy balance approach found in Equation F 1 ES vp Cp Thi Tho F 1 E 2 407x 10 J Energy balance on the ice and water system is found in Equation F 2 19 gallons of water 71 92 kg If the water remains at OC temperature differenctial within the ice bath will be 07 e dT 0 Thus the system energy balance becomes Equation F 3 E meh F 3 The mass of ice necessary to maintain this state is found using the latent heat of formation for ice in Equation F 4 J hy 333700 kg E EE 7 214kg F 4 lv Wice Mjce 8 15 8941bf In order to determine the heat transfer within the tubing the Reynoldsber for internaflow must be determined from Equation F 5 The critical Reynolds number for turbulenflow is 2300 4 Mdot ndy Red F 5
66. loving thanks to my family for their love and support throughout my undergraduate and graduate years at Baylor University It has been an amazing experience that I could not have had without them xi CHAPTER ONE Introduction Background As the demand for all forms of energy quickly outpaces the ability to provide it more reliable supplies are necessary to ensure consistent technological and economic growth The notion of dwindling energy supplies prompts technological innovation to delay or avoid the onset of an energy crisis Anderson 1 Efficiency of producers and conservation by consumers is complementary to developing alternative sources of reliable energy The home is one of the largest and most inefficient consumers of energy demanding approximately 10 600 kWh of energy per year EIA 2 The breakdown of a typical home s energy consumption shows that hot water heating currently accounts for 14 to 25 of the total energy demand ACEEE 3 There exists a great opportunity for solar thermal technologies to reduce this demand yet still provide reliable and efficient energy for comfort in the home The Solar Rating and Certification Corporation estimates that solar thermal systems will also benefit utility companies by reducing the peak demand load by 0 5 kW for each system installed Conventional electric and gas water heaters have high efficiencies of approximately 90 and 60 respectively however these loads are large and oft
67. low any flat plate collector array with a maximum power output of 13 5 kW utilizing the SRCC OG 300 solar profile to be evaluated Before any testing may occur the STCS circulator loop and the storage tanks must be filled with water to prevent any damage to the system An air relief valve is located at the highest point in the system after the outlet of the STCS Figure 14 follows the closed loop sequence listed below Closed Loop Filling Procedure 1 Connect the filling hose from the mains to the filling valve beneath the inlet of the pump 2 Ensure that the air relief valve on the outlet of the STCS is open as well as the filling valve and the valves on either side of the pump 3 Slowly turn the mains water completely on until water flows consistently out the air relief pipe to the drain and that the STCS is filled 32 Figure 14 Filling procedure diagram Close the air relief valve and then close the filling valve when the loop pressure is approximately 40 psi for safety Ensure the loop retains pressure and any air is prevented from entering the system Turn the mains faucet off The pressure in the closed loop may be monitored by the pressure gage near the expansion tank and reduced by slightly opening the filling valve Finally turn the pump on and listen for air bubbles the pump should be running silently If air bubbles do exist repeat steps 2 5 until there are no air bubbles 33 Storage Tank Filling Proced
68. lso activated during hours 11 and 12 which is evident in the second peak in the graph 58 Discussion The Solar Energy Factor for a single tank system and a double tank system were nine percent and twelve percent below data published by the SRCC These results are acceptable within the uncertainty bounds and laboratory conditions The main purpose was to achieve verifiable data that can be compared to SRCC data so future research can proceed From observing the behavior of the tanks pumps and outlet temperatures on a double tank test the SEF was found to be highly sensitive to the activation time of the auxiliary heating element Although the water entering the cold inlet of the auxiliary tank is preheated from solar energy the lower thermostat will react to the change in temperature quicker than the upper thermostat due to the buoyancy effects of a stratified tank Since the SRCC specifies a set amount of energy to be drawn from the system the SEF is really sensitive to how much the auxiliary elements are active and how long the pumps run The sensitivity of the SEF can be analyzed by taking the partial derivative of the SEF with respect to auxiliary energy as shown in Equation 8 This shows that the SEF is equally sensitive to the square of the auxiliary energy and the parasitic energy however since the auxiliary power required is 25 times greater than the parasitic the auxiliary energy is much more influential on the results SEF Q
69. ltions are Found on Data sheet The Incidence angle modifier is unitless Theta SubVI vi Calculates the angle of between direct radiation on a surface and the normal vecotr of that surface in radians for the midpoint of the solar hour preceding it Collector Azimuth Latitude Hour angle Incidence Angle Collector Slope Declination Cos Theta H float32 cosT cosT sin d sin cos B A sini d costf sin B cosf at cos d cos f cos B cos wyj cosi d sin f sin B cos g costw cos d sin B sin g sin w The Incidence angle has units of radians Theta mod SubVI1 vi Calculates the term that modfies the incident radiation on a surface For certain angles this modifier does not apply 80 Check with the SRCC specification sheet of the collector Incidence Angle cosT in Modifier ee Fake P S s 1 0 5 1 Long Lat SubVI vi This VI is constructed similarly to the TMY2 reader except that it only reads the first line containing the location information This VI is executed once Latitude Read TMY2 Latitude Local Longitude Longitude degrees Latitude and Longitude are read in degrees Latitude is converted to radians for Future calculations Total Insolation SubVI vi Calculates the Total isolation in Wh m 2 due to Beam diffuse and reflected radiation Insolation is a local variable Incidence Angle Collector Slope Iref Total Insol
70. mains chiller application 126 Table F 2 Secondary menu program settings Program Setting Auto ON ArUP OFF ArtE 0 08 PEA 12 VAL 5 Spld 1 Pc OFF Program OFF Stat OFF Irt 0 1St 0 PEND HOLD InPC 0 Filt 2 LPbr OFF Troubleshooting Code SnC bad e Turn controls off ensure all connections are secure and the thermocouple probe is connected Turn the controls back on Pump will not activate at desired set point temperature e Proceed to the Spld set point 1 differential in the Secondary Menu as described above Lower and save the value in this program The spld is a program that indicates to the unit to switch power when the differential between the process variable and the set point variable is at the given amount greater than the set point Example Sp 1d 5 Sp1 20 C If Pv gt Spld Sp1 25 C ON Else OFF 127 There is no flow in the heat exchanger e Ensure rotameter is fully open e Check pump for vapor locks by opening the gate valve and turning the mains faucet on to increase the pressure within the heat exchanger loop e Throttling the gate valve and isolation valve may also need to be performed with the mains on in order to dislodge any trapped air bubbles Performance Prediction Calculations The following calculations were performed in MathCAD to predict the performance of the mains chiller heat exchanger which comprises of a coiled length of copper tubing in an ice bath where the fluid to be coo
71. material or workmanship under the condition of normal use and service for a period of six 6 months from the date of purchase In the event that a defect malfunction or failure occurs or is discovered during the warranty period P3 will repair or replace at its option the product or component part s which shall appear in the reasonable judgment of P3 to be defective or not to factory specifications A product requiring service is to be retumed to P3 along with the sales receipt or other proof of purchase acceptable to P3 and a statement describing the defect or malfunction Meter All transportation costs shall be bome by the owner and the risk of loss shall be upon the Engineering unit Party initiating the transportation All items repaired or replaced thereunder shall be meter subjected to the same limited warranty for a period of six 6 months from the day P3 ships the repaired or replaced product The warranty does not apply to any product that Timer Function for has been subject to misuse tampering neglect or accident or as a result of unauthorized H meter alterations or repairs to the product This warranty is void if the serial number if any Watt and VA meter has been removed altered or defaced This warranty is in lieu of all warranties expressed or implied including the implied warranties of merchantability and fitness for a Voltage meter KWH meter and Timer particular purpose which are expressly excluded or disclaimed P3 shal
72. mplitude 3 3 V p p per m s nominal 1 V p p per ft s Source Impedance 8KQ Cable Type 2 conductor twisted pair with shield 22 AWG Cable Length 7 6m 25 ft standard 60m 200 ft maximum Ss Use PVDF Rot Rotor Pin for use in Deionized Water Use the Conduit Adapter Kit to protect the cable to sensor connection when used in outdoor environments See Ac cessories section for more information Use a sleeved rotor in abbrasive liquids to reduce wear Sensor plugs can be used to plug instal lation fitting after extraction of sensor from pipe GFt Max Pressure Temperature Ratings Standard and Integral Sensor e PP 12 5 bar 20 C 1 7 bar 90 C 180 psi 68 F 25 psi 194 F e PVDF 14 bar 20 C 1 4 bar 100 C 200 psi 68 F 20 psi 212 F Operating Temperature e PP 18 C to 90 C 0 F to 194 F e PVDF 18 C to 100 C 0 F to 212 F Wet Tap sensor e PP 7 bar 20 C 1 4 bar 66 C 100 psi 68 F 20 psi 150 F Operating temperature 18 C to 66 C 0 F to 150 F Max wet tap sensor removal rating 1 7 bar 22 C 25 psi 72 F See Temperature amp Pressure Graphs for more information Shipping Weight P51530 X0 0 454 kg 1 lb P51530 X1 0 476 kg 1 04 lbs P51530 X2 0 680 kg 1 50 lbs P51530 X3 0 794 kg 1 75 lbs P51530 X4 0 850 kg 1 87 lbs P51530 X5 1kg 2 20 lbs 3 8510 X0 0 23 kg 50 lbs 3 8510 X1 0 23 kg 50 lbs Standards and Approvals CE s FM Class
73. n Tank A given amount of losses are inherent in the closed loop system requiring extra head to be overcome by the pump In order to ensure safety and longevity of the pump precautions must be taken to avoid cavitation A WellSaver diaphragm tank is placed after the hot side exit of the STCS This tank is pressurized to 20 psi and absorbs any pressure surges due to initial start up of the pump by compressing a cushion of air within the tank This cushion of air is separated from the water by a rubber diaphragm in the middle of the tank The closed loop pressure can be monitored from a pressure gage located near the expansion tank For any closed loop 25 system being heated a small amount of thermal expansion of the working fluid will occur An increase in volume of a pressurized closed loop can be potentially dangerous if temperatures and pressures get too high City mains will pressurize the system to 60 psi however this pressure will not benefit performance so the pressure should be reduced to below 60 psi for safety precautions The closed loop pressure can be monitored on a pressure gage mounted at the top of the loop Flow Meters A Signet 8510 Rotor X Flow Sensor measures the actual flow rate of the closed heat exchanger loop through a paddle wheel style flow sensor that has accuracy of 1 full scale linearity The flow sensor is a pulsed output variety meaning that for every gallon of water that passes through the sensor a given numbe
74. n a solar thermal system are the second most important component and care in selecting the proper models is crucial to maximizing performance 7 A domestic solar hot water heating system normally contains only one or two tanks depending on location budget and hot water load The current configuration at Baylor University contains three tanks however the middle storage tank seen in Figure 10 is bypassed and not utilized during this experiment 80 gal Solar Storage Tank Mains and Tank Thermocouples Figure 10 Solar Domestic Hot Water heater simulator The SDHW consists of one 80 gallon storage tank and a 40 gallon auxiliary tank This allows for testing a single or double tank configuration which are two of 22 the most common systems found in domestic solar hot water heating The solar storage tank is a Rheem 80 gallon solar water heater with an integral wrap around double wall heat exchanger located on the lower half of the tank This tank receives power directly from one of the 208 V outlets to energize a single 3300 W auxiliary heating element located at the top of the tank and also contains the mains cold water inlet for the system The auxiliary tank is a General Electric SmartWater 40 gallon conventional electric water heater For a single tank configuration the auxiliary tank is bypassed and the hot water is drawn directly from the solar storage tank A three way automated valve is located on the cold inlet port o
75. nd accuracy that will produce quality location specific results A toggle switch 5 is implemented to read either format weather files or the standard SRCC OG 300 solar profile When the OG300 profile is enabled controls 1 5 are ignored and bypassed because the weather file already contains this information The Collector Data section consists of four steps 1 Enter the Collector Geometry e The slope and azimuth of the collector are user defined and are input in degrees with the azimuth being referenced east of south as negative and west of south as positive Beckman and Duffie 12 For OG 300 tests the slope is 40 degrees and the azimuth is set to due south at 0 degrees 2 Enter the Size and Quantity of the Array e The size of the specific collector can be found on the data sheet and is input in square meters 3 Enter the Collector Specifications 67 e The incidence angle modifier is found on the SRCC specification sheet and is only valid between 0 and 60 e The slope and y intercept of the linear efficiency equation are used in this analysis and can also be found of the SRCC specification sheet for the SLCR 40 found in Appendix E 4 Enter the Collector Fluid Specifications e The tested flowrate is found on the SRCC specification sheet and must be converted to kg s A correction factor must be calculated since the flowrate that is currently being used is different than the one tested and will not correlate to the value
76. ndards and the test methods used in achieving those values The results are discussed in chapter four and conclusions for system modifications and future research are presented in the final chapter A detailed description of the LabVIEW code is found in Appendix A and B which contain descriptions of each virtual instrument along with flow diagrams of the code architecture 16 CHAPTER TWO System Apparatus Solar Thermal Collector Simulator STCS In any solar thermal system the collector determines the overall performance It is the most important component in the system Previous research completed at Baylor University by Bolton 5 created a Solar Thermal Collector Simulator for a small array of flat plate solar thermal collectors shown in Figure 8 Outlet Heat Exchange Chambers Inlet Breakers Emergency Disconnect Figure 8 Solar Thermal Collector Simulator assembly 5 17 The STCS simulates the interaction between the sun and the solar thermal collectors usually found on the roof of a home and provides repeatable collector specific performance output for a given time period within 7 8 of theoretical calculations This is an extremely valuable asset when researching solar technologies because it allows the user to test various models of thermal collectors and systems without the expense or effort of installing an actual array The STCS consists of a modified Seisco RA 18 on demand hot water heater that allows
77. ns in the piping The chiller system will be active throughout the portion of the solar day requiring energy draws More ice will be necessary to maintain the ice bath 42 temperature at 0 C and can be procured from Aramark facility services at the Bill Daniel Student Union Building at Baylor University After the final energy draw the mains chiller can be deactivated by simply unplugging the controls from the outlet The 19 gallons of water in the mains chiller will cool to the set point temperature in approximately 35 minutes Calculations pertaining to the prediction of the performance of this basic heat exchanger can be found in Appendix F In order to quantify the energy delivered to the load the SRCC has designed a set of energy draws that represent average home hot water usage The six draws are scheduled to begin at 9 30 am solar time proceeding an hour after the first and consist of approximately 7 217 kJ and 11 gallons of water at a flow rate of 3 gpm Each draw will last approximately four minutes depending on the flow rate A net energy draw of 43 302 MJ is desired and can be achieved by adjusting the volume of water collected during each hour LabVIEW will indicate when each draw should occur with a green light indicator and that occurs for five minutes beginning at each draw Along with providing a visual sign the indicator also activates a LabVIEW control to concatenate a D on the end of each temperature measurement to
78. o DELL260_T Desktop L Toutlet txt 16 Flowread vi A pulse output variety flow sensor sends a 5 V pulse to the STCS every time a prescribed amount of fluid passes through the chamber This VI converts the accumulated pulses to kg s The Flow reader handles dropped packets similar to the Thermistor reader VI utilizing local variables An average of the past five previous values is created to filter the data received by the STCS dt Fl Flow Rates RS SE Dropped Packet D S EHF 5 low Rates Stores and sends previous dei a Sie Gd og gpm A n is calculated in value in case any packets u 05 to get gal H were missed T6 low is written in 5 Gr Flowrite vi This vi writes the flow rate of the closed heat exchanger loop to a file once ever thirty seconds 4C Documents and Settings cemo DELL260_TiDesktop Ly Flow txt calibrate vi This vi calibrates the power calculated from the theoretical collector output to the actual power delivered to the STCS Power raw EI Power adj v6 Wo Default KM float32 g g h 0 THUR Ay w pe w 0 000000093247287 pow w 3 0 0027738415 pow w 2 27 498302 w 91165 07402 0831 h 243 83 APPENDIX C Sample Calculations Single Tank Sample The calculations involved in determining the Solar Energy Factor are the same for a single and double tank system Parasitic Energy Qpar 366
79. o 176 F Relative humidity Maximum altitude Insulation category i Pollution degree 2 Standards and Approvals CE ULlisted Immunity amp Emissions EN61326 Manufactured under ISO 9001 and ISO 14001 515 Standard Mount Sensor Range 05 to in Sto Bin 515 Integral Mount Sensor shown with Transmitter sold separately ka 102mm 14 0in Y0 or 1 26 7 mm gt _ e 11 05in Pipe Range O5todin Y0 152mm 40 in St8in Y1 185mm 73 in 515 Wet Tap Mount Sensor with 3519 Wet Tap Valve See more information on the 3519 Wet Tap Valve refer to the 3519 product 3 297 men1t Mm P o mm2 in Pipe Range OSto s in Sto8in WOimandup FS 409mm 16 1 www gtsignet com X0 104 mond 1 in X1 137 mm 54 in 10 in and up X2 213 mmya A in Specifications General Flow Rate Range 0 3 to 6 m s 1 to 20 ft s Pipe Size Range DN 15 to DN 900 0 5 to 36 in Linearity 1 of full range Repeatability 0 5 of full range Min Reynolds Number Required 4500 Wetted Materials e Sensor Body Glass filled PP black or PVDF natural e O rings FPM Viton std optional EPDM or FFPM Kalrez e Rotor Pin Titanium Hastelloy C or PVDF op tional ceramic Tantalum or stain less steel e Rotor Black PVDF or Natural PVDF op tional Tefzel with or w o Fluoroloy B sleeve Electrical Frequency 19 7 Hz per m s nominal 6 Hz per ft s sinusoidal A
80. ocation The SEF assists in choosing an appropriate system for specific load and environmental conditions by providing a standardized performance rating that approximates the net energy savings Theory A solar thermal system utilizes the energy produced by the sun to heat water for domestic uses such as radiant floor heating systems showers and dishwashing A collector usually mounted on the roof of the home absorbs the sun s radiation and raises the temperature of the working fluid Solar radiation on a tilted flat plate collector integrated over one hour is known as insolation and is measured in kilowatt hours per square meter Wm Typical values of insolation for central Texas fall within the range of 5 0 5 5 kWh m per day NREL 6 Along with the solar collector a basic system usually has some form of thermal storage for the heated water A voy lt gt ANA V Collector Hot Water Load Circulator Pump Figure 2 Active solar domestic hot water heating configuration As shown in Figure 2 the hot fluid flows to thermal storage either directly or through a heat exchanger Systems that involve external sources of energy to pump the fluid and contribute supplementary heat to the water are considered active systems 7 As the stored water gains energy it heats up and upon reaching the desired temperature is ready to be drawn for domestic use Conventional hot water heating systems use elect
81. of the upper thermostat and energizes the lower element Connect the black wire to the lower terminal 4 on the thermostat and the red to the upper terminal 4 on the temperature limit control along with the blue wire from the upper heating element 6 Unscrew the terminals of the upper and lower element and attach the ring connectors of the analog power meters to the respective terminals securing each with the element terminal screws It does not matter which wire of the power meters goes to which terminal on the element 7 Plug the system into an available 208 V wall outlet The SRCC guidelines specify that the draw flow rate be approximately 3 gpm A stop is placed on the mains valve to throttle the flow rate while the gate valve on the mains chiller is for fine adjustments In order to calibrate the position of the gate valve a volume of water is allowed to collect in a bucket over a one minute period out of the draw valve to determine the mass flow rate The bucket is weighed and the mass of water collected is converted to gallons Approximately 11 4 kg or 25 lbs of water should be collected over a one minute period Appropriate adjustments are made to the position of the gate valve depending on the sampled flow rate The position is recorded and the valves are closed An exact flow rate of 3 gpm is not crucial to attain accurate results because the total mass of water drawn determines the net energy extracted from the system The mass of w
82. ofile of the solar storage tank in a single tank test 10 13 14 17 18 22 24 28 30 33 35 36 37 38 41 49 53 Figure 22 Solene SLCR80DC 80DB XE double tank drainback system 16 54 Figure 23 Temperature profile for the solar storage tank in a double tank test 57 Figure 24 Temperature profile for the auxiliary tank in a double tank test 58 Figure A 1 LabVIEW control panel interface 66 Figure A 2 Upper LabView result panel 69 Figure A 3 Lower LabVIEW results panel 70 Figure A 5 General state machine example with two states Weather and Idle 73 Figure E 1 Automatic valve manual override indicator and procedure 122 Figure F 1 Mains chiller sketch and operation 123 Figure F 3 Love 1600 Series control panel function 125 vi LIST OF TABLES Table 1 SRCC OG 300 rating conditions sec 7 3 11 Table 2 Software inputs and outputs with respective units Table 3 Solene Chromagen SLCR 40 collector specifications Table 4 Standard weather profile draw schedule solar time Table 5 Testing condition criteria Table 6 SEF test values compared to SRCC values for a single tank test Table 7 Parasitic and auxiliary energy loads and time active Table 8 Solar Fraction for single tank tests and SRCC data Table 9 SEF test values compared to SRCC data for a double tank test Table 10 Parasitc and auxiliary energy loads for a double tank test Table 11 Solar Fraction for a doub
83. ontroller and the pump is assumed to be turned on at the beginning of the solar day when insolation is present 15 and is turned off at the onset of solar night Since the operation of the pump influences the Q term of the SEF a correction was made for the controller by comparing the outlet temperature of the STCS to the temperature at the bottom of the solar storage tank Whenever this temperature differential is above 2 75 C the pump is considered on This temperature differential is chosen as a conservative estimate for the setting on an average controller Since this data is recorded throughout the test a conservative correction can be made afterward for the parasitic energy consumed by the pump Chapter Descriptions This thesis outlines the implementation of a solar thermal collector simulator with a multi tank system and calculates the efficiency of a single and double tank system The goal behind these experiments is to confirm the feasibility of testing solar domestic hot water systems with the STCS and achieving results validated by SRCC data The SRCC efficiency ratings will provide a baseline standard to compare test results to similar commercial systems that are currently available A testing procedure has been developed that follows as closely as possible to SRCC guidelines Chapter two outlines the specifications and performance of each component of the current set up Chapter three explains the SRCC sta
84. opper Plate Copper Fin Absorber Coating Black Chrome Insulation Side Polyurethane Foil faced Insulation Back Mineral Wool amp Polyurethane TECHNICAL INFORMATION Efficiency Equation NOTE Based on gross area and P Ti Ta Y Intercept Slope SI Units n 0 704 1 7983 P I 0 0470 Gr 0 735 5 365 W m C IP Units n 0 704 0 3169 P I 0 0046 Gr 0 735 0 945 Btu hr ft F Incident Angle Modifier S 1 cos 6 1 0 S 6 lt 60 Model Tested SLCR 30 Ky 1 0 0 2011 S 0 0069 S Test Fluid Water Ki 10 0 19 S Linear Fit Test Flow Rate 52 mls 0 82 gpm REMARKS July 2007 Certification must be renewed annually For current status contact SOLAR RATING amp CERTIFICATION CORPORATION c o FSEC 1679 Clearlake Road e Cocoa FL 32922 321 638 1537 Fax 321 638 1010 110 Submittal Data Information mer bn mme ee Maco Model 003 Cartridge Circulator Effective September 1 2003 Supersedes December 1 2002 Job Enginee Contractor Rep ITEM NO MODEL NO IMP DIA G PM HEAD FT H P ELEC CHAR Features Application Reduces Erosion Corrosion and Flow Noise in The Taco 003 is designed for circulating hot or chilled fresh water in open or closed loop shorter pipe run applications lower flow applications Flow characteristics are ideal for Domestic Hot Water Recirculation Standard High Capacity Output Compact De
85. or used in this experiment is a Solene Chromagen SLCR 40 with a total panel area of 7 4 m The collector parameters can be found in Table 3 and the data sheet in Appendix E Table 3 Solene Chromagen SLCR 40 collector specifications Specification Quantity Gross Area 7 4 m Y Intercept 0 735 W m C Slope 5 365 W m Incident Angle Modifer Ka 0 19 Test Flow Rate 0 82 gpm The software runs two independently timed loops one for calculating the insolation and the other for calculating power to the STCS Each loop is run on a real time basis to simulate an actual solar day The primary goal in simulating an actual day is to subject the system to energy inputs and outputs that simulates domestic hot water use Accurate timing is also critical to ensure available insolation occurs during the solar day and coincides with energy draws so the tanks can be recharged and then maintain storage temperatures The main loop samples once an hour to calculate solar time incidence angle and total insolation The SRCC document TM 1 recommends that critical temperatures are read once every thirty seconds so the second loop samples at this frequency and receives a data packet containing twelve temperature readings two flow meter outputs and any error codes that the STCS sensed 14 The desired sampled temperatures are then used to calculate and send the most updated power required to the STCS 21 Storage Tanks The storage tanks i
86. ors as seen in Figure 13 Bank of 6 33 kQ resistors Figure 13 Analog power meters 30 Each clock is wired to the terminals of a resistive heating element and the time can be zeroed for each test For a single tank test only one analog meter will be used on the upper element of the solar storage tank At the conclusion of each test the time elapsed can be read from the position of the hour and minute hands It is important to record the exact time the element was active at the conclusion of each test because the clocks will continue to log time as long as power is provided to the tanks This value along with the power for each element which is initially measured with an Amprobe ACD 41PQ power meter is used in calculating the auxiliary energy consumed by the heating elements For the double tank configuration two clocks were implemented on the auxiliary tank one for the upper and lower element respectively 31 CHAPTER THREE Experimental Methods The SRCC OG 300 document pertains to strict guidelines that must be followed in order to accurately rate the performance of commercially available solar thermal systems This procedure adheres as closely as possible to these guidelines utilizing commercially available storage tanks circulator pumps piping and connections It also accounts for laboratory methods and modifications such as the installation of flow meters power meters and thermowells The current configuration will al
87. ower consumption of the pump is an important variable to consider when researching high efficiency systems Expansion Tank Pressure Gage Kl d Heat Exchanger Cold Outlet Taco 009 ba Circulator Pump Figure 11 Closed circulator loop assembly 24 The Taco pump is also recognized for extremely low maintenance and ease of servicing which will benefit future research on this system The 009 model is an impeller driven constant speed circulating pump that is located at the exit of the heat exchanger There are two ball valves on the pump one located on both the inlet and exit flanges which greatly assist filling and pressurizing the closed heat exchanger loop The pump will be manually controlled to simplify parasitic energy calculations Whenever insolation is present in the solar profile and power can be calculated the pump will be activated Insolation occurs from 8 00 am through 5 00 pm in the OG 300 profile thus providing a quantifiable amount of power be delivered to the system otherwise the power will be zero and the pump can be turned off This will avoid any possible damage to the STCS and the system A correction factor to account for the absence of a differential controller is implemented to conservatively estimate the time the pump would have been turned off due to a temperature difference less than 2 75 C between the outlet of the STCS and the bottom of the solar storage tank Expansio
88. power meters goes to which terminal on the element 6 Plug the system into an available 208 V wall outlet RED BLACK HIGH LIMIT CONTROL BOTH N C s OPEN ON TEMPERATURE RISE I80 F N C RED BUTTON RESETS BOTH CIRCUITS UPPER THERMOSTAT ei Ze N C N C OPENS AND N O CLOSES ON TEMPERATURE RISE UPPER ELEMENT Figure 17 Single tank wiring diagram 37 Double Tank Wiring Diagram Make sure that the water heater is unplugged Remove the upper and lower thermostat covers on the auxiliary tank and solar storage tank and locate the terminals found in Figure 18 Disconnect the element of the solar storage tank and connect the auxiliary red power wire to the upper terminal 3 and the auxiliary black power wire to the lower terminal 2 On the auxiliary tank ensure that the black power wire is connected to the upper terminal and the red power wire is connected to the upper terminal 3 RED BLACK HIGH LIMIT CONTROL BOTH N C s OPEN ON TEMPERATURE RISE IST N C RED BUTTON RESETS BOTH CIRCUITS UPPER THERMOSTAT N C OPENS AND N O CLOSES ON TEMPERATURE RISE N C OPENS ON TEMPERATURE RISE LOWER ELEMENT Figure 18 Double tank wiring configuration 38 4 Connect the yellow element wire to the lower terminal 2 on the thermostat and the blue element wire to the upper terminal 4 on the temperature limit control 5 A red wire and black wire is located to the right
89. r of 5 volt pulses are sent to the STCS counted and then reported to the user The K Factor which is the calibrated number of pulses per gallon for 4 in PVC pipe is 272 72 This sensor is placed after the exit of the pump on the cold side of the heat exchanger at least 50 inside pipe diameters downstream to ensure fully developed flow The Rotor X is used in conjunction with a Signet 8550 Flow Transmitter to visualize the current flow rate and condition the signal to the STCS with an accuracy of 0 5Hz The K Factor is manually programmed into the transmitter to accurately measure the signal from the Rotor X The combination of flow sensor and transmitter provide an uncertainty in the flow rate readings of the closed loop of 0 0459 gpm The flow meter measurements are used in updating power calculations 26 Mains Chiller Testing conditions dictate the water entering the solar storage tank from the mains to be 14 4 C to simulate an average mains temperature that may be encountered in various locations The temperature of the mains at Baylor University varies from 15 C to 21 C depending on time of day and year water load in the building and location in the building The sporadic nature of the mains presents a difficult challenge for repeatable results that must be compared to strict SRCC data In order to overcome this a chiller was developed and implemented that effectively reduces and maintains the temperature of the mains water to
90. r auxiliary power is found to be 1 2 2 SP p Stpanx 14 092 W The accuracy of analog power meters is found to be one second amp Is taux 4530s Auxiliary element was activated for 45 min during a single tank test Q Paneta The energy consumed by the auxiliary element The overall uncertainty of the delivered energy can now be found to be 1 2 Dk Baus IB Paux 5t ie Saux 6 389 x 10 J Delivered Energy by 0 015 Accuracy of Omega Totalizer as percentage of reading V Ilgal Single draw volume by by V Sy 6 246 x 10 KN Fixed uncertainty for draw volume When measuring temperatures a K type thermocouple and Fluke digital thermometer were used bt t 2 2K Accuracies of respective instruments bread 0 756K 1 2 2 Fixed uncertainty of temperature Bat bt bread measurement devices 104 Inlet and outlet temperatures were measured once every thirty seconds of the period of a draw Data from one draw can be found below 15 1 58 1 43 14 3 58 3 44 14 3 58 3 44 14 5 58 2 Ti To 43 7 14 4 57 9 AT To Ti K K 43 5 14 8 57 8 43 14 7 57 2 42 5 14 7 55 2 40 5 Standard deviation for the sampled temperature differences Sap 115K Students t value for 8 roii samples T Random uncertainty for temperature difference over one draw COAT STAT 8 0 267 K Overall uncertainty for temperature measurements 1 2 2 2 SAT Bye STAT In o
91. rder to calculate the delivered energy the temperature differences over one draw are averaged 7 1 AT avg S gt AT 43 025 K i 0 The energy delivered during one draw is found to be J k Cp 4184 p 1000 kg K 3 m 6 Qdel1 p V Cp AT avg Qdel1 7 496 x 10 J 105 The fixed uncertainty in the energy delievered during one draw 2 Bag 0 V Cp 34 7 P CP AT avg al 5 The random uncertainty for a set of six draws throughout a solar day 7132590 8280350 5 8048080 S 4 22 1 Qdraw 7494990 J Qdel gt Qdraw 6x 10 J i 0 4548610 6755540 The standard deviation of the six draws is O draw 1345968 J The student s t value for six samples is t 2 015 t O draw 5 Sr Aen 4 52 x 10 J The overall uncertainty of the energy delivered throughout the day 2 2 2 del Bae St draw 5 Overall Uncertainty Since the SEF is calculated by summing up the energy delivered during six independent draws the delivered energy is multiplied by six to provide an approximate SEF value 2 2 Sdel Saux Q del m Dear Qdel USEF ees Qaux j Qpar Qaux One Qaux T Qpar 106 APPENDIX E Equipment Manuals Table E 1 SRCC Solar Profile The outdoor ambient temperature solar radiation and incident angle profiles are defined as follows Solar Time Ambient Temperature Solar Radiation Incident Angle hour CC F W hr m Btwhr f 0 1 13 55 4 0
92. readings Volts Current Watts Frequency Power Factor and VA The unit will start to accumulate KWH and powered duration time hour after power is applied 2 Press Volt Key for true RMS Voltage Volts display 3 Press Amp Key for true RMS output current Amps display The Watt VA Key is a toggle function key Press the Watt VA key once to display Watt meter then press key to display VA meter The LCD will display Watts as the active power where VA is the apparent Power VA Vrms Arms The HZ PF is a toggle function key Press the HZ PF key once to display the frequency Hertz then press key to display the Power Factor HZ is the Frequency of output Voltage where PF is the Power Factor PF W Vrms Arms The KWH Hour is a toggle function key Press the KWH Hour key once to show the cumulative energy consumption since power was applied to the unit Then press key to display the cumulative time since power was applied to the unit Consumption will be displayed in Kilowatt Hours from 0 01 KWH to 9999 KWH Time will initially be displayed as Hours Minutes from 00 00 and switch to Hours to 9999 Counters will recyle to zero when they reach their maximum To reset remove power from unit momentarily WARNING Do not exceed maximum ratings as detailed on label P3 INTERNATIONAL CORPORATION LIMITED WARRANTY P3 INTERNATIONAL CORPORATION P3 warrants to the original retail purchaser only that its product is free from defects in
93. ricity to energize resistive heating elements to heat the water directly In contrast solar thermal systems use electric energy as supplemental heating elements for auxiliary back up only If the water is below the system set point or minimum desired temperature then the electric element will provide the extra heat necessary to achieve the desired water temperature Two very common configurations found in residential applications are a single tank and double tank system A single tank system shown in Figure 3 usually has the storage and auxiliary element within the same tank Collector Hot Outlet ains Inlet Te Heating Element Heat Exchanger Figure 3 Single tank configuration In the double tank system shown in Figure 4 the auxiliary tank contains a pair of heating elements and receives preheated water from the solar storage tank Collector Mains Inlet Hot Outlet Heating Elements III Solar Storage Auxiliary Storage Tank Tank Pump Figure 4 Double tank configuration The water is heated in the first tank using solar energy and as the water flows into the auxiliary storage tank the electric power required by the element in the second tank is significantly reduced The SRCC rating method for collectors components and systems allow comparisons regardless of system configuration The performance rating for Solar Domestic Hot Water systems is the Solar Energy
94. ront panel where a user interface including control inputs and outputs are located for analytical purposes and the block diagram where VIs are created and data is processed Front Panel The front panel of the user interface consists of a window with two tabs Control Panel and Results The tabbed window manages multiple inputs and outputs in an organized interface The control panel consists of instructions and two sections of inputs Weather and Geography and Collector Data which are entered by the user to determine the output power of a collector Figure A 1 is a screenshot of the control panel that interfaces with the user 65 Figure A 1 LabVIEW control panel interface The Weather and Geography section includes a file search dialogue box for the location of weather data files 1 the time period in hour of the year to be 66 analyzed 2 a pull down menu for the specific time zone 3 and an input for the ground reflectance of the specific area 4 The control program has been augmented to receive two different types of weather data files the OG 300 solar profile and a typical meteorological year TMY2 format The TMY2 data file is compiled by the National Renewable Energy Laboratory from weather stations specific to a certain location around the world and is comprised of various data such as ambient temperature and direct radiation that is averaged from 1961 to 1990 These files provide the repeatability consistency a
95. s of the collector efficiency equation This equation can be found in Appendix B Once these values are correctly input to the control panel and the STCS is turned on by plugging in the 208 V power cord and switching the electric breakers The testing may now commence beginning at solar midnight taking careful note to schedule energy draws at a convenient time during the simulated 24hr period As the simulation iterates the results can be viewed simultaneously on graphical outputs The Results tab referenced in Figure A 2and Figure A 3 contains a vast array of outputs that convey the behavior of the system under current conditions The specific latitude and longitude 1 are displayed along with the current hour of the year day of the year and time of day 2 Solar calculations occur in an offset time frame known as solar time 3 which accounts for the sun s angular motion across the sky Beckman and Duffie 12 This value coincides with actual simulation time and is displayed for reference purposes along with the actual simulation timer 4 to 68 coordinate energy draws An indicator is placed next to the simulation timer to alert the user when energy draws are supposed to occur permat Collector loop test 7 11 09 UG 200 vi Front Panel Ek ER Aen Boet Grerste G r kg Heo lei an 25 ae AR Figure A 2 Upper LabView result panel The ambient temperature 5 is extracted from the weather data file The instantaneous effic
96. s to provide a better average tank temperature and also be recorded by the STCS and the LabVIEW software The stratification of the temperatures within the tanks over time can also be measured to provide a more accurate temperature profile of the tank The extra storage tank located between the solar storage and auxiliary tanks should also be incorporated into future configurations to test how increased thermal storage affects the performance of the system The automatic three way valve located on top of the auxiliary tank can be integrated to analyze hybrid single double tank systems Finally Typical Meteorological Year weather data files should be tested in the LabVIEW control software in order to calculate the performance and behavior of systems with location specific data 63 APPENDICES 64 APPENDIX A LabVIEW User Manual National Instruments LabVIEW control software is a program that allows control and analysis code to be written through a combination of wiring inputs and outputs of modular icons to form a logical flow of information between them Unlike text based codes that execute processes line by line in a control flow manner LabVIEW is based on a data flow model where functions are not executed until they receive all of the information necessary Functions in LabVIEW also known as Virtual Instruments VI may be run simultaneously in parallel if they are independent of each other LabVIEW contains two main sections the f
97. shown are demanded by zone requirements they must be specifically requested To prevent corrosion proper pH levels in transfer fluid must be maintained Solaraide models meet all current state requirements for solar storage tanks The tanks are Rheemglas lined and are designed to operate up to 150 PSI A special 1 2 NPT opening is provided D i for installation of a probe type thermostat a Et COPPER COIL DATA Type L eent Maximum pressure 150 P Maximum temperature 185 F WATER CONNECTION NIPPLES ALL 3 4 N P T Tube D 5 8 Solaraide HE Coil Capacity Length of Tubing Tank Capacity Gallons Around Tank Ft COLLECTOR 80 Gallons 2 2 120 120 Gallons 2 6 143 PRESSURE DROP THROUGH COIL Feet of H 0 Head Loss Feet Flow Rate 80 Gallon 120 Gallon 1GPM 12 16 REQUIRED FOR NON 2 GPM 48 57 GRAVITY SYSTEMS 3 GPM 10 0 12 0 In keeping with its policy of continuous progress and product improvement Rheem reserves the right to make changes without notice Rheem Water Heating 101 Bell Road Montgomery Alabama 36117 e www rheem com PRINTED IN U S A 06 08 WP FORM NO 101 16 Rev 13 115 P4400 Kill A Watt Operation Manual Congratulations on your purchase of the Kill A Watt Power Meter Cared for properly this unit will provide you with years of service 1 The LCD shows all meter
98. shown in Figure 16 This sequence will also be used to conclude energy draws 34 Auxiliary port plug Isolation valve Figure 15 Mains chiller tank and valve assembly Figure 16 Sequential draw valve procedure After the circulator loop and storage tanks are filled the system must be configured to either a double or single tank system by switching the automated valve found on top of the auxiliary tank and appropriately wiring the water heating thermostats A procedure for sequencing the automatic valve can be found in Appendix F The following diagrams illustrate the wiring configuration and procedure used to appropriately wire the system 36 Single Tank System Wiring Diagram 1 Make sure that the water heater is unplugged Remove the thermostat cover on the solar storage tank and identify the following terminals found in Figure 17 2 Connect the black element wire to the lower terminal 2 on the thermostat and the red element wire to the upper terminal 4 on the temperature limit control 3 Ensure that the extra red and black wires that energize the auxiliary tank are removed from terminals 1 and 3 and protected with electric tape or wire nuts 4 Unscrew the terminal of the heating element being careful not to drop the screws into the insulation 5 Attach the ring connectors of the analog power meters to the respective terminals securing each with the element terminal screws It does not matter which wire of the
99. sign Heat Recovery units Water Source Heat Pumps and Potable Water systems The unique replace Quiet Efficient Operation able cartridge contains all of the moving parts and allows for easy service instead of replacing the Direct Drive Low Power Consumption entire circulator The compact low power consumption design is ideal for high efficiency jobs Unique Replaceable Cartridge Design Field Pump Dimensions amp Weights ive a B C D F c Shipwe Self Lubricating z No Mechanical Seal Tos 23 6 7 Unmatched Reliability Maintenance Free 003 BC4 1 2 Swt 5 1 8 4 1 8 105 2 1 8 27 Bronze Construction with Sweat Threaded or 003 BT4 3 4NPT 5 5 8 4 718 124 2 51 27 Union Connections 003 BC4 1 Union 5 5 32 4 11 32 110 2 31 32 27 Materials of Construction Casing Volute Bronze E E Stator Housing Steel gl Cartridge Stainless Steel oH Lu Impeller Non Metallic Optional OK if over Shaft Ceramic 20 psi Bearings Carbon Electrical Data O Ring amp Gaskets EPDM Model Volts Hz Ph Amps RPM HP W3AlModes 115 Tal la 3250 140 Model Nomenclature Motor Permanent Split Capacitor B Bronze Sweat Type Impedance Protected BC Bronze Sweat Panel Mount Tappings Motor BT Bronze Threaded Options 220 5071 220 601 230 60 1 100 1 10 50 6071 BC Bronze
100. st gate valve to the desired flow rate position 3 Now open the isolation valve fully then the draw valve to allow 11 gallons to flow into the drain monitoring the volume by the Omega Flow Totalizer 44 4 After finishing the draw close the draw valve then the isolation valve and finally the gate valve in that order This will allow the system to remain pressurized and the chiller to activate cooling of the next batch of water 5 Allow the system to recharge for the next hour and perform steps 1 4 again at 10 30 am solar time continuing to 2 30 pm solar time After the final energy draw the system must be allowed to continue operating until the end of the solar profile which terminates at solar hour 24 or solar hour 17 depending on the file implemented The latter part of the test will consist of energy gains from insolation and auxiliary heating to compensate for standby losses At the conclusion of the test the energy consumed by the circulator pump must be recorded from the Kill A Watt power meter Also for the respective auxiliary element the time energized must be read from the analog power meters These values will be incorporated into the calculations regarding parasitic and auxiliary energy loads found in Chapter 1 Throughout the test LabVIEW records several quantities for further data analysis including inlet and outlet of the STCS mains temperature flow rate of the closed loop solar storage tank temperature and usefu
101. system as well as the solar storage tank The inlet and outlet of the STCS is connected to the closed circulator loop on the SDHW system with PEX High Cross linked Polyethylene high temperature pipe and fittings Multiple safety precautions are implemented on the STCS due to the proximity of 208 V outlets and up to 120 gallons of water Two breakers and two emergency shutoff switches comprise the manual shutdown of the system The automatic safety precautions consist of an over temperature switch that operates if the fluid temperature reaches 93 3 C as well as a leak detection sensor that eliminates power to the elements if activated Extreme caution must be taken to ensure that water is always in the heat exchanger chambers whenever the STCS is in operation Damage to the heating elements controls and structure of the STCS can occur if operated without a heat transfer medium or if left to stagnate with a no flow condition while power is delivered to the elements Controlling the STCS is accomplished by communicating power levels temperatures and operating codes with an external computer 19 LabVIEW User Interface A computer utilizing National Instruments LabVIEW 8 0 control software manages the STCS during tests LabVIEW controls the useful output power from the collector and monitors system performance The control software calculates theoretical output power of an array of flat plate collectors and communicates these control values to
102. terate and send data to the consumer loop which will not iterate until it has received and processed that data The primary logic in the controls lies within comparing the current time to the start time This simple control algorithm is implemented for several processes including the producer and consumer loop stop sequences communication with the STCS and the draw indicator Two state machine structures were utilized for the producer and consumer loops 71 Read Weather File Calculate Insolation Calculate Power Request STCS Data Communicate with STCS tio Current Start Time Continue Figure A 4 LabVIEW block diagram flow chart 72 The state machines allow different processes to be run depending on the indicated state that is controlled by Boolean operations and the timer as shown in Figure A 5 Zeen Set tg S E Weather S Idie Default g Calculations occur in this case in e Wi DBL e DED gt eat E e Seng 12 gt Figure A 5 General state machine example with two states Weather and Idle The producer loop reads in the weather file performs the solar calculations and sends total insolation ambient temperature and the incidence angle modifier kta to the consumer loop once an hour The consumer loop takes the producers data calculates the useful power required and communicates with the STCS once every thirty seconds A request is initially made by LabVIEW for inlet
103. th The Large Crimp Tool Note Use the crimp tool only to install PEX tube fitting systems meeting ASTM F1807 for brass or copper insert fittings and F2159 for plastic insert fittings A Important Always refer to the tube manufacturers product assembly Instructions when using the crimp tool 1 Measure and cut the tube Be sure you have a square burr free cut An uneven or jagged cut may cause an improper connection 4 Position the tool so the crimp ring is completely covered by the tool jaws Keep the tool at a 90 angle to the fitting and close it completely Squeeze handles together to complete the crimp 5 Open the tool handles to release jaws from the crimped fitting 2 Next slip a copper 6 Measure the crimped ring crimp ring onto the with Zurn Go No Go gauge tube Do not use See table below Do not hose clamps measure bumps on ring where Jaws met If Go on gage does not fit or if No Go does fit S then cut out connection replace fitting and ring adjust and calibrate the tool and recrimp The following dimensions are the ASTM maximum and minimum 3 Now Insert the fitting into the crimped ring diameters for crosslinked polyethylene PEX pipe tube up to the fitting shoulder Fitting installations Position the crimp ring 1 8 Inch Shoulder to 1 4 inch from the end of the NY ce Pe lela ring may produce a weak Tube Size gt 3 4 lieft Ring may be Minimum Diameter 0 700 0 815 0
104. the amount of power delivered to the working fluid to vary depending on the amount of theoretical output power that is desired The STCS has four heat exchanger chambers and has been modified to output 13 5 kilowatts at maximum power due to the voltage at the available power outlet Water the working fluid is pumped through the chambers shown in Figure 8 gaining energy as it flows The inlet and outlet temperatures of the collector simulator are measured as well as three intermediate temperatures that monitor for over temperature conditions Five R25 thermistors shown in Figure 9 make up the STCS temperature sensing system which monitors the inlet outlet and three intermediate temperatures Auxiliary inputs Figure 9 STCS control circuit with temperature sensors 18 Seven auxiliary inputs are available on the STCS for additional temperature monitoring throughout the system Figure 9 displays the location of the auxiliary inputs on either side of the control circuit Each auxiliary input has three pins an input ground and a 5 volt A jumper is located next to each port that allows the auxiliary input to be subject to the same current conditions as the five permanent thermistors If the jumper is removed the 5V pin provides a signal to the input pin The inlet and outlet temperatures were calibrated to an accuracy of 1 015 C Bolton 5 Three K type thermocouples were used to measure inlet and outlet temperatures of the
105. the STCS as well as displaying and writing an appropriate warning message to the user Temps Flowrate Warning Message Element Control 86 L8 30000 Recieves Data from the hardware on the local UDP port UDP Packet Form normal AxxxxAxxxx QxxxxxQxxxxx error EOT ENFCELDD Prevents the UDP receiving Function From timing out Dw Gett Ip EEH E arning Message lement Control Thermistor 5 has an error S S Leak Detected Thermread vi The Thermistor reader VI extracts the thermistor readings from the data packet If a packet is dropped and is returned empty a local variable retains the previous value and passes that to the consumer loop to be used in calculations pecas Dropped Packet i To_Mains Data Out To_Solar Tank To_Outlet 88 Dropped Packet Mrs H Stores and sends previous value in case any D were missed STCS Thermistors let and outlet temperatures are lin degrees Celcius Nr dse NI ot E sae ye oo Data string received VE Dom box Auxiliary Thermistors Iddle Left Lower Left 06 To write vi Writes the inlet and outlet temperatures with time stamps to independent external files Dropped Packet Ti Draw To Tsolar Tank Tmains Toutlet The inlet and outlet temperatures are recorded with an appropriate time stamp For Further data reduction C Documents and Settings cem
106. the STCS via Ethernet Universal Datagram Protocol UDP Appendix A contains a detailed user s manual for the LabVIEW program Appendix B details the calculations performed in LabVIEW Table 2 lists the inputs requested by the user and the outputs provided by the control software The user begins by loading a weather data file followed by location and collector orientation information Table 2 Software inputs and outputs with respective units Inputs Units Outputs Units Weather Data N A Hour of Day std solar hr Collector Slope deg Total Insolation kWh m Collector Azimuth deg STCS Inlet Temperature C Collector Area m STCS Outlet Temperature C Quantity of Collectors N A Ambient Temperature C Incident Angle Modifier N A Mains Temperature C Collector Efficiency Slope Wim C Solar Tank Temperature C Collector Y intercept W m C System Outlet Temperature C Tested Flow Rate Kg s STCS Power W Energy Gain MJ STCS Flow Rate kg s Instantaneous Efficiency N A Warnings N A LabVIEW displays many outputs that describe the current system behavior and environmental conditions Every solar thermal collector commercially manufactured in the United States must be rated and documented by the SRCC 20 Collector data sheets are provided by the manufacturer and specific data from these sheets regarding the collector efficiency equation incident angle modifier and the tested flow rate must be input to LabVIEW The specific collect
107. the solar storage tank and the location of this thermowell with reference to the tank 47 Several iterations were made to calibrate the thermostat to the appropriate set point temperature This was vital to achieve accurate results because the thermostats directly controlled the activation of the auxiliary heating elements Me Pl ae eeneg SP eS rem r a Seene Ze Figure 20 Location of threaded thermowell and surface mounted thermocouple on solar storage tank The DOE specifies the test to begin when the tanks are fully mixed to the set point temperature of 57 2 C 2 8 C This condition was reached by varying the temperature of the thermostats and running the STCS at a fixed power level During preheating and steady state conditions temperature readings were made based on the thermocouples at the top and bottom surfaces of the tank 48 Single Tank Test Results A single tank system was subject to the insolation and ambient temperature data from the solar profile set forth in the OG 300 document and allowed to operate for 24 hours simulating hot water usage during the solar day and standby losses during solar night The current configuration was very similar to a Solene SLCR80DC 80DB drain back system shown in Figure 21 using water as the working fluid 16 The system specification sheet can be found in Appendix E E W LE J a Cold Supply J Solor Tonk Figure 21 Solene SLCR80DC 80DB singl
108. u i OO nx OO j s For the average single tank test the SEF is less sensitive to the time that the auxiliary element and parasitic devices are active In a single tank test the element operates for a shorter period of time compared to the double tank test This is due to 59 the proximity of the thermostat on the upper portion of the tank constantly near the warmer water The auxiliary energy and parasitic energy are approximately the same magnitude and thus have similar influence on the SEF for a single tank system To account for this the system set point must be carefully calibrated and the analog power meters must be closely monitored Several minutes on the analog power meters or a solar storage tank that is initially too cool may skew the active time for the parasitic and auxiliary energy measurements Both system configurations performed as expected following procedures set forth by the SRCC and DOE The single tank tests were more accurate to the SRCC data however they consistently delivered lower outlet temperatures during energy draws This can be attributed to the mixing of cold water from the mains inlet and also to the thermostat control 60 CHAPTER FIVE Conclusions and Recommendations Conclusions In summary the Solar Domestic Hot Water Simulator at Baylor University found the Solar Energy Factor for a single tank to be 4 46 0 06 which is 9 below data verified by the SRCC on a similar commercially a
109. umber of Draws 6 one at the beginning of each hour starting at 9 30 am Solar radiation energy on a sloped surface integrated over a one hour period is known as insolation Jr The radiation energy incident on a surface is affected by interactions with clouds dust and water vapor in the atmosphere Capturing all of these factors in one model is challenging and is best accommodated through a simplified model In order to accurately model the sky and determine total insolation the isotropic diffuse sky model was chosen which assumes a clear sky conditions and that the radiation incident on a tilted surface can be broken down into three 12 components direct beam b isotropic diffuse d and ground reflected Jpg as seen in Figure 6 vAy ye Collector Figure 6 Components of incident radiation on a tilted surface The amount of diffuse and reflected radiation incident on the collector is related to the collector angle through its respective view factors for the sky and ground Beckman and Duffie 12 Equation 6 is the isotropic diffuse model of the sky EE E n Ip 6 where Ir is the insolation on the surface J is the beam component normal to the surface J is the diffuse radiation component and Jpg is the diffuse radiation reflected from the ground Finally is the slope of the collector and is the main variable in 13 determining the view factors for the diffuse and reflected components o
110. ure Once the closed heat exchanger loop is filled proceed to filling the storage tanks For the majority of operation this procedure will be performed once unless maintenance must be performed on one of the tanks or thermocouples It is essential to fill the chiller system first and ensure that all air bubbles are removed from the heat exchanger coil to avoid vapor locks in the pump A diagram outlining the valves and connections on the mains chiller can be found in Figure 15 l First ensure the mains chiller is connected to the water faucet and that the isolation valve is closed and the gate valve is open Unscrew one of the auxiliary port plugs on the top of the chiller to allow air to escape Ensure the rotameter is fully open as well Turn on the mains and allow the chiller to fill paying close attention to the level of the water Once the chiller is full close the gate valve and replace the auxiliary port plug on the top of the tank With the isolation valve and gate valve closed activate the controls and let the pump run to flush out any air bubbles If necessary open the gate valve to increase pressure in the chiller to free any trapped air Next open the draw valve and then the isolation valve to allow the storage tanks to fill with water from the mains When the tanks are full water will flow consistently out the draw valve Close the draw isolation gate and mains valve sequentially to pressurize the system as
111. vailable system A double tank system performed equally as well with a Solar Energy Factor of 2 64 0 043 which was 12 below the SRCC s rating for a similar system Both hardware systems performed equally well for simulating computer generated efficiency results provided by the SRCC It is important to remember that the results provided by the SRCC are extrapolated from a computer simulation utilizing the Transient Energy System Simulation Tool TRNSYS Detailed parameters are input for each component however there is a limit where the computer simulation cannot encompass the small losses and the operation of an actual system SRCC results represent standardized performance under ideal conditions and tend to be conservative because they are intended to be a benchmark for performance to assist in choosing the correct system Actual performance depends on a wide variety of factors including geographic location hot water usage and timing quality of system components and quality of installation The results of these tests show that accuracy and repeatability for the testing facility at Baylor University is verified These tests provide a baseline standard for 61 future research into the development of modifications to the domestic solar hot water heating system Future Recommendations There are several recommendations regarding modifications to the current system for future research For more accurate results regarding parasitic ener
112. ws is 5 7 4 308 x 10 J Qde 2 H ren i 0 draw 537900 The student s t value for six samples is t 2 0153 t O draw 5 Srdraw 1 807 x 10 J The overall uncertainty of the energy delivered throughout the day can now be found 2 2 2 del Bee Stgraw Sdel 4 586x 10 J Overall Uncertainty Since the SEF is calculated by summing up the energy delivered during six independent draws the delivered energy is multiplied by six to provide an approximate SEF value n 2 2 2 Del 8 Saux Qdel S Spar Huel USER Rs Oa t Qpar Qaux F Qpar Qaux SE 102 Parasitic Energy Dpar 0 002 Qpar 3564000 Spar par Qpar 3 Spar 7 128x 10 J Auxiliary Energy Double Tank Uncertainty Accuracy of Kill A Watt power meter as percentage of reading Sampled parasitic energy usage for a single tank test Fixed uncertainty for parasitic energy use Random Uncertainty taken from five independent measurements of the auxiliary element power during a single tank test 3088 2960 3023 T i 4 3 3050 Pi 3 P 2 527x 10 W 3040 i 0 3028 Student s t value at 95 conficdence for 5 t 2 015 samples Standard Deviation of Power measurements op 41 96W The random uncertainty for the five power measurements is thus found to be Op Stpaux t 14 092W 103 The fixed uncertainty is the accuracy of the Amprobe power meter dp 0 1W Thus it follows that the uncertainty fo
113. ystems to loads 8 because insolation ambient and mains temperature and utility prices all vary by location Thus the Solar Energy Factor is critical in determining the annual economic and energy savings a solar thermal system will provide System Overview The Solar Domestic Hot Water SDHW system simulator replicates a domestic solar hot water heating configuration The main components of the actual SDHW system shown in Figure 5 consist of a Solar Thermal Collector Simulator STCS an 80 gallon solar hot water heating tank with a heat exchanger a 40 gallon standard hot water heating tank and an inline circulator pump The user can control and monitor the system from an external computer Figure 5 shows the first storage tank of the SDHW with an integrated wrap around heat exchanger to which the STCS and the circulator pump are connected completing a closed heat exchange loop The heat exchanger consists of 120 ft of copper tubing wrapped around the bottom half of the first storage tank An inline pump provides the flow in the closed loop through the STCS and heat exchanger to transfer energy to the stored water The second storage tank is a conventional electric auxiliary tank with two heating elements that may be bypassed for single tank testing Water from the mains flows through the storage tanks and back to the drain through a series of valves located on the inlet and outlet of the system Circulator Pump

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