chapter2PropertiesofPureSubstances

2-1PureSubstance2-1-1DefinitionofPureSubstanceAhomogeneoussubstanceispuresubstance2-1-2PhasesofPureSubstanceSolidLiquidGas

2-2PhaseChangeProcessofPureSubstance2-2-1ConstantPressureProcessofWater

pv123455’1’2’3’4’5”1”2”3”4”cTv123451’2’3’4’5’1”2”3”4”5”cT=constantvaporLiquid+VaporCriticalpointLiquidLiquid+solidSolid+VaporsolidpTTripleline

2-2-1PropertiesofWater1.Onepoint：CriticalpointC2.Twolines：Saturatedwaterline,Saturatedvaporline3.ThreeRegions:Compressedwaterregion,Saturatedmixtureregion,superheatedvaporregion4.Fivestates:Compressedwater,Saturatedwater,Saturatedmixture,Saturatedvapor,superheatvapor

2-3-1p-v-TSurface2-3P-v-TsurfaceandP-Tdiagram

2-3-2p-TdiagramPTSolidVaporliquidMeltinglineVaporizationSublimationExpandonfreezingExtractonfreezingCriticalpoint

2-4PropertyTables2-4-1SaturatedLiquidandVaporOnepropertyisenoughtoCalculateotherproperties.t℃P,MPav’v”h’h”s’s”1000.10130.001041.6738419.062676.31.3069755510.00116042791.42.33076.4289Enthalpy----thecombinationproperty:H=U+PVOr,perunitmassh=u+Pv

2-4-2SaturatedMixtureOnepropertytocalculatesaturatedproperties,buthowtodeterminethepropertiesofsaturatedmixture?Onespecialpropertytocalculatethefractionofliquidandvapor,thequality

2-4-3SuperheatedVaporTwoindependentpropertiesareusedtoCalculateotherpropertiesT℃P=0.1MPav,m3/kgh,kJ/kgs,kJ/kg.K10012793642776.47.5438

2-4-4ReferencestateandreferencevalueWater:Saturatedliquidat0.01℃istakenasthereferencestate,whereu=0s=0R-12:Saturatedliquidat-40℃istakenasthereferencestate,whereu=0s=0Notice:Thereferencestatedifferwithdifferenttables

2-5-1TheIdeal-GasThemoleculesofideal-gashavenovol