Chapter10

RefrigerationCycle10-1Vapor-CompressionCycle10-1-1TheReversedCarnotCycleTs4123THTLCoefficientofPerformanceDisadvantagesProcess2-3isdifficulttobeFulfillincompressorProcess4-1willdoharmtoturbine10-1-2TheIdealVapor-CompressionRefrigerationCyclecondenserEquipments:1234compressorExpansionvalveevaporatorTsTHTL1234condensercompressorevaporatorCapillarytube10-1-3TheCOPofVapor-CompressionCycleh-sdiagramhs1234Usuallyp1,p2areavailablehs1234Fromp1,geth1”,s1”h1=h1”s1=s1”Fromp2,s1,geth2Fromp2,geth2’h3=h2’h4=h3p-hdiagramph123410-2RefrigerantAmmoniaCFC(chlorofluorocarbons)waterGoodrefrigerantHighenthalpyofvaporizationNottoolowevaporatorpressureNottoohighcondenserpressureNontoxicNoncorrosiveChemicallystableLowcost10-3HeatPumpAnequipmentAbsorbingheatfromenvironmentforheatingpurposeTsTHT01234HeatpumpforheatingHeatpumpforrefrigeration10-4InnovativeVapor-compressionRefrigerationSystems10-4-1RegenerativeVaporCompressioncycleEquipmentscondenserevaporatorHeatexchangerseparatorcompressorTsTHTL1234T-sDiagram2’1’10-4-2CascadeRefrigerationSystemscondenserevaporatorTsT0T-sDiagram10-4-3MultistageCompressionRefrigerationSystemscondenserevaporatorFlashchamber123heatexchanger456789Ts12345678910-4-4MultipurposeRefrigerationSystemswithaSingleCompressorcondenserFreezerrefrigerator123456AlternativepathTs1234510-4-5LiquefactionofGasHeatexchangerMakeupgasLiquidremovedMultistagecompressor12345Ts12134510-5GasRefrigerationcycle10-4-1EquipmentsHeatexchangerQHHeatexchangerQLcompressorturbineTsp2p11234T0TL10-4-2

COPofGasRefrigerationCycleTs1234T0TLTs1234T0TLSince

TodecreasecompressionratiocanincreaseCOPToTodecreasecompressionratiowilldecreasepowerratioTsT0TLTsT0TL12453q6q10-4-3RegenerativeGasRefrigerationCycleHeatexchangerQHHeatexchangerQLcompressorturbineregenerator12345610-6AbsorptionRefrigerationSystemheatcondenserevaporator=compressorRefrigerant:AmmoniaTransportmedium:WaterRefrigerant:WaterTransportmedium:Lithiumbromide10-6AdsorptionRefrigerationSolarenergyActivecarbone