Latent Heat of Vaporization - What is Nuclear Power

Latent heat of vaporization is the amount of heat added to or removed from a substance to produce a change in phase, namely to vaporize a substance. Facebook Instagram Youtube TwitterSkiptocontent KnowledgeBaseNuclearPowerPlantNuclearPhysicsReactorPhysicsThermalEngineeringMaterialsRadiationProtectionSearch SearchTheheatofvaporizationdiminisheswithincreasingpressure,whiletheboilingpointincreases.Itvanishescompletelyatacertainpointcalledthecriticalpoint.Ingeneral,whenamaterial changesphase fromsolidtoliquidorfromliquidtogas,acertainamountofenergyisinvolvedinthischangeofphase.Inthecaseofliquidtogasphasechange,thisamountofenergyisthe enthalpyofvaporization (symbol∆Hvap;unit:J),alsoknownasthe (latent)heatofvaporization orheatofevaporation.Latentheatistheamountofheataddedtoorremovedfromasubstancetoproduceaphasechange.Thisenergybreaksdowntheintermolecularattractiveforcesandmustprovidetheenergynecessarytoexpandthegas(the pΔVwork).Whenlatentheatisadded,notemperaturechangeoccurs.Theenthalpyofvaporizationisafunctionofthepressureatwhichthattransformationtakesplace.Latentheatofvaporization–waterat0.1MPa(atmosphericpressure)hlg=2257kJ/kgLatentheatofvaporization–waterat3MPa(pressureinsideasteamgenerator)hlg=1795kJ/kgLatentheatofvaporization–waterat16MPa(pressureinsideapressurizer)hlg=931kJ/kgTheheatofvaporizationdiminisheswithincreasingpressure,whiletheboilingpointincreases.Itvanishescompletelyatacertainpointcalledthecriticalpoint.Abovethecriticalpoint,theliquidandvaporphasesareindistinguishable,andthesubstanceiscalledasupercriticalfluid.Theheatofvaporizationistheheatrequiredtocompletelyvaporizeaunitofsaturatedliquid(orcondenseaunitmassofsaturatedvapor).Itisequaltohlg=hg−hl.Theheatnecessarytomelt(orfreeze)aunitmassatthesubstanceatconstantpressureistheheatoffusionandisequaltohsl=hl−hs,wherehsistheenthalpyofsaturatedsolidandhlistheenthalpyofsaturatedliquid.Latentheatofvaporization–waterat0.1MPa.Dominantpartofheatabsorbed. References:NuclearandReactorPhysics:J.R.Lamarsh,IntroductiontoNuclearReactorTheory,2nded.,Addison-Wesley,Reading, MA(1983).J.R.Lamarsh,A.J.Baratta,IntroductiontoNuclearEngineering,3ded.,Prentice-Hall,2001,ISBN:0-201-82498-1.W.M.Stacey,NuclearReactorPhysics,JohnWiley&Sons,2001,ISBN:0-471-39127-1.Glasstone,Sesonske.NuclearReactorEngineering:ReactorSystemsEngineering, Springer;4thedition,1994,ISBN: 978-0412985317W.S.C.Williams.NuclearandParticlePhysics. ClarendonPress;1edition,1991,ISBN: 978-0198520467KennethS.Krane.IntroductoryNuclearPhysics,3rdEdition,Wiley,1987, ISBN: 978-0471805533G.R.Keepin.PhysicsofNuclearKinetics. Addison-WesleyPub.Co;1stedition,1965RobertReedBurn,IntroductiontoNuclearReactorOperation,1988.U.S.DepartmentofEnergy,NuclearPhysicsandReactorTheory. DOEFundamentalsHandbook, Volume1and2. January 1993.AdvancedReactorPhysics:K.O.Ott,W.A.Bezella,IntroductoryNuclearReactorStatics,AmericanNuclearSociety,Revisededition(1989),1989,ISBN:0-894-48033-2.K.O.Ott,R.J.Neuhold,IntroductoryNuclearReactorDynamics,AmericanNuclearSociety,1985,ISBN:0-894-48029-4.D.L.Hetrick,DynamicsofNuclearReactors,AmericanNuclearSociety,1993,ISBN:0-894-48453-2. E.E.Lewis,W.F.Miller,ComputationalMethodsofNeutronTransport,AmericanNuclearSociety,1993,ISBN:0-894-48452-4.Seeabove:FirstLawSearchfor: reportthisadPrivacyPolicyOurWebsitefollowsalllegalrequirementstoprotectyourprivacy.VisitourPrivacyPolicypage.TheCookiesStatementispartofourPrivacyPolicy.EditorialnoteTheinformationcontainedonthiswebsiteisforgeneralinformationpurposesonly. Thiswebsitedoesnotuseanyproprietarydata. VisitourEditorialnote.CopyrightNoticeIt’ssimple:1)Youmayusealmosteverythingfornon-commercialandeducationaluse.2)Youmaynotdistributeorcommerciallyexploitthecontent,especiallyonanotherwebsite.See:CopyrightNoticeContactus:Ifyouwanttogetintouchwithus,pleasedonothesitatetocontactusviae-mail:[email protected]xx