二氧化碳跨临界循环放热过程换热性能研究Study of Heat Transfer Performance for Heat Rejection Process in Transcritical Carbon Dioxide Cycle
马一太,杨俊兰,管海清,卢苇
MA Yi-tai;YANG Jun-lan;GUAN Hai-qing;LU Wei (Tianjin University;
摘要(Abstract)：
二氧化碳跨临界循环放热过程处于超临界区 ,由于在准临界点附近CO2 的热物理参数变化非常剧烈 ,超临界区流体的换热有别于传统制冷剂 ,气体冷却器的换热优劣对系统性能影响较大。为了能设计出高效的气体冷却器 ,应该对这一过程的换热性能作一全面了解。本文主要讨论了制冷剂CO2 在气体冷却器中的换热特点 ,以及流体温度、高压侧压力、质量流速、热流密度、管径和含油量等因素对换热的影响 ,最后探讨了换热关联式和气体冷却器型式的研究进展。
The heat rejection process in transcritical carbon dioxide cycle takes place above the supercritical condition. Due to the physical properties exhibit extremely rapid variations with the change of temperature near the pseudocritical point, the heat transfer performance of supercritical fluids are very different from that of conventional refrigerants. The heat transfer performance of gas cooler has large effect on the system. Consequently, comprehensive understanding of heat transfer characteristics in this process should be done in order to design high efficiency gas cooler.The heat transfer performance in the gas cooler and the effect of bulk temperature, heat rejection pressure, mass flow rate, heat flux, tube diameter and lubricant quantity on the heat transfer are discussed. At last,the heat transfer correlation and the development of gas cooler are introduced respectively.
关键词(KeyWords)：
二氧化碳跨临界;放热过程;气体冷却器;换热
transcritical carbon dioxide;heat rejection process;gas cooler;heat transfer
基金项目(Foundation): 高等学校博士学科点专项科研基金项目 (D0 2 0 0 10 5 )
作者(Authors):
马一太,杨俊兰,管海清,卢苇
MA Yi-tai;YANG Jun-lan;GUAN Hai-qing;LU Wei (Tianjin University;
参考文献(References)：
- [1] PettersenJ,etal.Heattransferandpressuredropcharac teristicsofsupercriticalcarbondioxideinmicro channeltubesundercooling[A]ZingerliA ,GrollE .A .InfluenceofrefrigerationoilontheheattransferandpressuredropofsupercriticalCO2 duringin tubecooling[A].PitlaS,etal.NumericalheattransferanalysisinheatexchangersfortranscriticalCO2 system[A].YinJianMin,etal.DesignstrategiesforR 744gascooler[A]PreliminaryProceed ingsofthe4thIIR GustavLorentzenConferenceonNaturalWorkingFluidsatPurdue[C]200099106;269278;307314;315322.
- [2] ChaobinDang,EijiHihara.Heattransfercoefficientofsupercriticalcarbondioxide[A].PreliminaryProceedingsofthe5 thIIR GustavLorentzenConferenceonNaturalWorkingFluidsatGuangzhou[C]China,September17-20,2002100107.
- [3] LiaoSM ,ZhaoTS.Measurementsofheattransfercoeffi cientsfromsupercriticalcarbondioxideflowinginhorizon talmini/microchannels[J].TransactionsoftheASMEJournalofHeatTransfer,2002,124:413420.
- [4] PitlaS,GrollA ,RamadhhyaniS .Newcorrelationtopredicttheheattransfercoefficientduringin tubecoolingoftur bulentsupercriticalCO2[J].InternationalJournalofRe frigeration,2002,25:887895.
- [5] YinJianMin,BullardCW ,HrnjakPS.R 744gascoolerdevelopmentandvalidation[J].InternationalJournalofRefrigeration,2001,24:692701.
- [6] LiaoSM ,ZhaoTS,JakobsenA .Acorrelationofoptimalheatrejectionpressureintranscriticalcarbondioxidecy cles[J].AppliedThermalEngineering,2000,20:831834.
- [7] KrasnoshechekovEA ,KuraevaIV ,ProtopopovVS .Localheattransferofcarbondioxideatsupercriticalpressureundercoolingconditions[J].TeplofizikaVysokikhTemop eratur,1970,7(5):922930.
- [8] BaskovVL ,KuraevaIV ,ProtopopovVS.Heattransferwiththeturbulentflowofaliquidatsupercriticalpressureintubesundercoolingconditions[J].TeplofizikaVysokikhTemoperatur,1977,15(1):96102.
- [9] GnielinskiV .Newequationforheatandmasstransferinturbulentpipeandchannelflow[J].Int.ChemicalEngi neering,1976,16:359368.
- [10] PetrovNE ,PopovVN .Heattransferandresistanceofcarbondioxidecooledinthesupercriticalregion[J].ThermalEngineering,1985,32(3):131134.
- [11] PetukhovBS.Heattransferandfrictioninturbulentpipeflowwithvariablephysicalproperties[J].AdvancesinHeattransfer,1970,6:504564.
- [12] PettersenJ,HafnerA ,SkaugenG .Developmentofcom pactheatexchangersforCO2 air conditioningsystems[J].IntJ.Refrig,1998,21(3):180193