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《地源熱泵地理埋管換熱器不同運(yùn)行模式實(shí)驗(yàn).研究與模擬》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在應(yīng)用文檔-天天文庫(kù)。
1、摘要differentflowrateandoperatingmodewereappliedforexperimentaltesting,accordingtothedifferentoperatingmode,threephasesofexperimentaltestinghadbeendivided,theywereall—daycontinuousoperation,daytimeoperationonly,andall—dayintermittentoperation.All—daycontinuousoperationmodewasseparatedintothreep
2、artsbasedontheflowrateof0.65m3/h,0.7m3/h,and0.8m3/h.Theresultsshowed,thebestaveragequalityofheattransferpermeterofboreholeandcoefficientofsystemperformanceare53.66W/mand3.91W/Wrespectivelyatthe0.8m3/hflowrate.So0.8m3/hwaschosenastheexcellentflowrateoftheexperimentaltesting,intermofdifferentra
3、tioofon—offtime,daytimeoperationonly,anliall-dayintermittentoperationweredeployed.Itfoundthatthequalityofheattransferbecameincreasinglyreducedalongwiththetimeprolonged.Underthesamecondition,thesystemperformanceofintermittentoperationisbetterthantheall—daycontinuousoperation,thedaytimeoperatio
4、nonlywasthebestamongthem,theaveragequalityofheattransferpermeterofboreholeandcoefficientofsystemperformanceare55.14W/mand3.96W/Wrespectively.Finally,basedonheattransfermechanismofU-tubeunderground,forasingleborehole,atransientone—dimensionalline-sourcemodeloutsideboreholeandquasi·-three--dime
5、nsionalsteady-·statemodelinsideboreholewerepresented.InviewofdifferentoperationmodeofGSHPVI南京師范大學(xué)碩士學(xué)位論文systemwouldcausetime—varyingloads,heatpulseanalysistheorywasused.Underthecontinuousoperationmode,aseriousofcontinuousrectangularheatpulseswasapproximatedbyaseriousstepheatpulse;undertheinter
6、mittentoperationmode,aperiodofcyclicheatingofthegroundwasapproximatedbythesummationofacontinuousmeanloadandasingleheatingpulse.Then,superpositionwasappliedtodealwithsuchvariableanddiscontinuousloads.Combinedwiththermalresistanceinsideborehole,theinlet&outletwatertemperatureofU-tubeexchangerco
7、uldbesimulated.Comparedthesimulatedvalueswithexperimentalresults,theaverageabsoluteerrorandaveragerelativeerrorisSOlittle.Thiscomparisonsuggestedthemodelinghashighaccuracyandrationality,andcanbeusedtoinstructpeopletodesign,simulatetheU—tubehe