Transcription
Combining solar and district heating in IDA ICEBuildSim-Nordic 25.9.-26.9.2014 EspooJorma Heikkinen, Krzysztof Klobut, Ari Laitinen, Miika RämäVTT Technical Research Centre of Finland
IntroductionThe project aims to find future districtheating solutions for residential districtsHow much solar energy can be utilized inconnection with district heating in a smallhouse?District heating substation model,including solar heating, wasimplemented into building energysimulation (IDA-ICE)10/10/20142
District heating substation10/10/20143
District heating substation, with solar collectors10/10/20144
Standard heating plant (boiler) in IDA ICEBuilding10/10/20145
Some useful system components in IDA ICE10/10/20146
New district/solar heating substation modelSunny day 23.6 at 10:00Room heating10/10/20147
Building heating powerLocated in Helsinki, FinlandHeating power, W1200010000House 28000House 16000Hot water use profile4000200001.1. 31.1. 2.3. 2.4. 2.5. 2.6. 2.7. 1.8. 1.9. 1.10. 1.11. 1.12. 1.1.Date10/10/20148
Solar collector efficiencyCollector efficiencyIrradiation 01020304050Mean temperature-outdoor temperature, K10/10/20149
Example of solar collector heating power (W)House 2, collector area 6 m2 , tank volume 400 lSolar irradiation and collector power3000Collector power, WIrradiance, ate21.6.22.6.23.6.24.6.Less solar heat at the end of the week10/10/201410
Example of tank temperaturesHouse 2, collector area 6 m2 , tank volume 400 l807060504030201016.6.Temperature stratification in the storage tank, at0.2 m intervals from the bottom, oC17.6.18.6.19.6.20.6.Date21.6.22.6.23.6.24.6.The tank is cooling down towards the end of the week10/10/201411
Example of DHW heat exchanger operationHouse 2, collector area 6 m2 , tank volume 400 lDistrict heating heat exchanger power (hourly average), kWDateThe storage tank can sometimes cover also DHW circulation need (250 W)10/10/201412
Example of heating heat exchanger operationHouse 2, collector area 6 m2 , tank volume 400 lHeating power,kWFrom district heatingFrom storage tankDateTemperature stratification in the tank, DegC, 0.2 m intervals frombottomThe storage tank can cover heating need few hours in the evening10/10/201413
Energy cumulation during the yearHouse 2, collector area 6 m2 , tank volume 400 lCumulative energy during the year, kWh18 00016 00014 00012 00010 000DH to heating exchangerDH to DHW heat exchangerSolar energy to tankFrom tank to DHWFrom tank to heatingFrom tank to DHW circulation8 0006 0004 0002 00001.1. 31.1. 2.3. 2.4. 2.5. 2.6. 2.7. 1.8. 1.9. 1.10.1.11.1.12. 1.1.Date10/10/2014Solar energy from March to SeptemberUsed mainly for domestic hot water14
Savings in district heating energy due to solar heatHouse 2Energy saving max. 54% of DHW heating need (4675 kWh, 220 l/day)Savings per collector area decrease with increasing collector areaStorage tank volume has only a small influenceSolar energy to DHW circulation small10/10/201415
Savings in district heating energy due to solar heatHouse 1Energy saving max. 73% of DHW heating need (2820kWh, 133 l/day)10/10/201416
Effect on district heating return temperatureHouse 2, collector area 6 m2 , tank volume 400 lDistrict heating return temperature (DegC), 240 hour average, oC6055504540Without solar system35With solar .Date1.8.1.9.1.10. 1.11. 1.12.1.1.About 3 degrees higher with solar energyDecreases CHP (Combined Heat and Power) power production17
ConclusionsComplicated heat production systems can be built into IDA ICESimulation less robust than using the standard heating plantSollar collectors save max 50% - 70 % of domestic hot water heating needRelative savings 200 - 400 kWh/m2 per collector area, decreasing with areaTank size does not have a big influenceIt is challenging to combine economically solar heating with district heatingBetter susbtation concepts neededEnergy for hot water circulation from the tank is small in the present arrangementOne possibility is to heat the bathroom with the heating system water, instead ofdomestic hot water circulation10/10/201418
TECHNOLOGY FOR BUSINESS
Combining solar and district heating in IDA ICE BuildSim-Nordic 25.9.-26.9.2014 Espoo . The tank is cooling down towards the end of the week 10 20 30 40 16.6. 17.6. 18.6. 19.6. 20.6. 21.6. 22.6. 23.6. 24.6. . One possibility is to heat the bathroom with the heating system water, instead of domestic hot water circulation. TECHNOLOGY FOR .
