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doi10.3969/j.issn.2095-4468.2013.03.101*200240[]5COP4.0045%9433%[]ThermodynamicAnalysisonSub-coolingProcessinCO2Trans-criticalRefrigerationCycleDENGShuai*,WANGRu-zhu,DAIYan-jun(InstituteofRefrigerationandCryogenics,ShanghaiJiaoTongUniversity,Shanghai200240,China)[Abstract]Thefeasibilityofapplyingthesub-coolingtechnologytotheCO2trans-criticalcyclewasdiscussed,andtheperformanceofnewcyclewasanalyzedaswell.Particularly,sub-coolingconversedfromsolarthermalenergywasanalyzedthroughsimulationforpossibleapplications.ThecalculationresultsshowthatcoolingCOPofthecyclereachedto4.00andcanbeincreasedby45.0%whentemperaturedifferenceofsub-coolingis5insummer.Whilesub-coolingisrealizedbyasolar-drivenabsorptionrefrigerationcycleandthedrivingtemperatureis94,theassistedcoolingcapacitytransformedfromregenerativeenergyreachedto33%ofthetotalcoolingcapacity.Thedifferenceinthesub-coolingprocessbetweenconventionalrefrigerantssubcriticalcycleandCO2trans-criticalcyclewasalsodiscussedbriefly.[Keywords]Naturalrefrigerant;Carbondioxide;Vaporcompressionrefrigeration;Sub-cooling*533_@jNB5B0[1][2][3]1533320139ChineseJournalofRefrigerationVol.33,No.3Sep.1981-80010007988emailedwarddengstu.edu.cno.2012AA004[1][2]1121-22-33-44-111234[4]EES[5]EES[6]CO2COP/(kJ/kg)222.13[7]31-2-3-4-5-145511-2-3-4-5-1[3][8-11]/MPa33320139ChineseJournalofRefrigerationVol.33,No.3Sep.1/(kJ/kg)(a)/(kJ/kg)(b)3/[8-9][10-11]COP2.2[4,7]451554515COPRqRw(1)(2)3RqRwCOP4425--sqbqhhRqhh(1),3332--swbhhwRWhh(2)R22R134aR410aR1234yf455119%10%25Rw(2)Rw0Rw0//4Rq/5RRqRw//MPa33320139Vol.33,No.3Sep.//w/6COPRqRw5COP1.14/63728(5)COP4.002.7545%/78COPx0COP34COPOCOP/8COP4152EES[5]6kW4kW[12]9(a)15COPCOP6.00948532.5COP2.009(b)(contributionratio)%/COP33320139ChineseJournalofRefrigerationVol.33,No.3Sep.2.0028CP4.02890229433%90/(a)COP/(b)95102414.7kWh19.0kWh22.6%16.4kWh13.7%1)2)3)10611Q[8-9]///kWh33320139Vol.33,No.3Sep.11311113-3/(kJ/kg)11/[3][1]71)2)3)28COP2.75COP4.0045.5%9022%9433%4)13.7%22.6%[1]SchoenfeldJM.Integrationofathermoelectricsubcoolerxyfy[D]M,,UyfMy(3)/33320139ChineseJournalofRefrigerationVol.33,No.3Sep.intoacarbondioidetranscriticalvaporcompressioncclererigerationsstem.asterthesis2008niversitoarland.8[8]V.P.Carey.LiquidVaporPhase-ChangePhenomena[M].Taylor&Francis,London,1992.[9]MingZhang,R.L.Webb.Correlationoftwo-phasefrictionforrefrigerantsinsmall-diametertubes[J].ExperimentalThermalandFluidScience,2001,25(1):131-139.[10]Shah,M.M.,1978.Ageneralcorrelationforheattransferduringfilmcondensationinsidespipes[J].Int.J.HeatMassTransfer22,547-556.[11]Cavallini,A.,Censi,G.,DelCol,D.,Doretti,L.,Longo,G.A.,Rossetto,L.,2001.ExperimentalinvestigationoncondensationheattransferandpressuredropofnewHFCrefrigerants(R134a,R125,R32,R410A,R326ea)inahorizontalsmoothtube[J].Int.J.Refrigeration24,73-87[12]Cavallini,A.,Censi,G.,DelCol,D.,Doretti,L.,Matkovic,M.,Rossetto,L.,Zilio,C.,2006.Condensationinhorizontalsmoothtubes:anewheattransfermodelforheatexchangerdesign[J].HeatTransferEng.27,31-38.[13]M.K.Dobson,J.C.Chato.CondensationinSmoothHorizontalTubes[J].ASMEJournalofHeatTransfer,1998(120):193-213.[14]HaraguchiH,KoyamaS,FujiiT.CondensationofrefrigerantsHCFC22,HFC134aandHCFC123inahorizontalsmoothtube(1streport,proposalsofempiricalexpressionsforthelocalfrictionalpressuredrop)[J].NIPPONKIKAIGAKKAIRONBUNSHUBHEN,1994,60(574):2111-2116.2013619~201506[1][2],,.[J].,2007,26(3):6-9.[3]PottkerG,HrnjakP.Effectofcondensersubcoolingoftheperformanceofvaporcompressionsystems:Experimentalandnumericalinvestigation[C].InternationalrefrigerationandairconditioningconferenceatPurdue,July16-19,2012.[4]DuddumpudiVS.TranscriticalCO2AirSourceHeatPumpforAverageUKDomesticHousingwithHighTemperatureHydronicHeatDistributionsystem[D].Masterthesis,2010,Universityofstrathclydeengineering.[5]BeckmanWA,Klein,SA.EngineeringEquationSolver.Version8[EB/OL].[2013-05-04].[6]SpanR,WagnerW.ANewEquationofStateforCarbonDioxideCoveringtheFluidRegionfromtheTriplePointTemperatureto1100KatPressuresupto800MPa[J].JournalofPhysicalandChemicalReferenceData,1996,5(6)556[7],.[M].:,2007.[8]LiaoSM,ZhaoTS,JakobsenA.Acorrelationofoptimalheatrejectionpressuresintranscriticalcarbondioxidecycles[J].Appliedthermalengineering,2000,20:831-841.[9]CecchinatoL,CorradiM,MinettoS.Acriticalapproachtothedeterminationofoptimalheatrejectionpressureintranscriticalsystems[J].AppliedThermalEngineering,2010,30,1812-1823.[10],,,,.CO2[J].,2010,31(9):1441-1444.[11]ZhangFZ,JiangPX,LinYS,ZhangYW.EfficienciesofsubcriticalandtranscriticalCO2inversecycleswithandwithoutaninternalheatexchanger[J].AppliedThermalEngineering,2011(31):432-438.[12].[D].:,2001.33320139ChineseJournalofRefrigerationVol.33,No.3Sep.2:109-19.