Chapter10RefrigerationCycle

10-1Vapor-CompressionCycle10-1-1TheReversedCarnotCycleTs4123THTLCoefficientofPerformance

DisadvantagesProcess2-3isdifficulttobeFulfillincompressorProcess4-1willdoharmtoturbine

10-1-2TheIdealVapor-CompressionRefrigerationCyclecondenserEquipments:1234compressorExpansionvalveevaporator

TsTHTL1234

condensercompressorevaporatorCapillarytube

10-1-3TheCOPofVapor-CompressionCycleh-sdiagramhs1234

Usuallyp1,p2areavailablehs1234Fromp1,geth1”,s1”h1=h1”s1=s1”Fromp2,s1,geth2Fromp2,geth2’h3=h2’h4=h3

p-hdiagram

ph1234

10-2RefrigerantAmmoniaCFC(chlorofluorocarbons)waterGoodrefrigerantHighenthalpyofvaporizationNottoolowevaporatorpressureNottoohighcondenserpressureNontoxicNoncorrosiveChemicallystableLowcost

10-3HeatPumpAnequipmentAbsorbingheatfromenvironmentforheatingpurposeTsTHT01234

Heatpumpforheating

Heatpumpforrefrigeration

10-4InnovativeVapor-compressionRefrigerationSystems10-4-1RegenerativeVaporCompressioncycleEquipmentscondenserevaporatorHeatexchangerseparatorcompressor

TsTHTL1234T-sDiagram2’1’

10-4-2CascadeRefrigerationSystemscondenserevaporator

TsT0T-sDiagram

10-4-3MultistageCompressionRefrigerationSystemscondenserevaporatorFlashchamber123heatexchanger456789Ts123456789

10-4-4MultipurposeRefrigerationSystemswithaSingleCompressorcondenserFreezerrefrigerator123456AlternativepathTs12345

10-4-5LiquefactionofGasHeatexchangerMakeupgasLiquidremovedMultistagecompressor12345

Ts121345

10-5GasRefrigerationcycle10-4-1EquipmentsHeatexchangerQHHeatexchangerQLcompressorturbine

Tsp2p11234T0TL

10-4-2COPofGasRefrigerationCycleTs1234T0TL

Ts1234T0TL

SinceTodecreasecompressionratiocanincreaseCOPToTodecreasecompressionratiowilldecreasepowerratio

TsT0TL

TsT0TL12453q6q10-4-3RegenerativeGasRefrigerationCycle

HeatexchangerQHHeatexchangerQLcompressorturbineregenerato