Sea water temperature difference energy

Twosystems

Theprincipleofthermoelectricpowergenerationistouseaworkingmediumtotransfertheheatenergyinthesurfaceseawatertothedeepcoldwatertogeneratepower.Oceanthermoelectricpowergenerationmainlyadoptstwotypesofcirculationsystems,openandclosed.

Opencyclepowergenerationsystem

Opencyclesystemmainlyincludesvacuumpump,warmwaterpump,coldwaterpump,flasher,condenser,turbinegeneratorandothercomponents.Thevacuumpumpfirstpumpsthesystemtoacertaindegreeofvacuum,andthenstartsthewarmwaterpumptopumpthesurfacewarmwaterintotheflashevaporator.Sincethesystemhasmaintainedacertaindegreeofvacuum,thewarmseawaterboilsandevaporatesintheflashevaporatorandbecomessteam..Thesteamisejectedfromthenozzlesthroughthepipelinetodrivetheturbinetorun,anddrivethegeneratortogenerateelectricity.Thelow-pressuresteamdischargedfromtheturbineentersthecondenser,iscooledbythecoldseawaterpumpedupfromthedeepseawaterbythecoldwaterpump,re-condensesintowater,andisdischargedintothesea.Inthissystem,seawaterastheworkingmediumissuckedintotheflashevaporatorbythepumptoevaporate,pushingtheturbinetodowork,andthendirectlydischargedintotheseaafterbeingcondensedbythecondenser.Therefore,thesystemofthisworkingmodeiscalledanopencirculationsystem.

Closed-cyclepowergenerationsystem

Thewarmseawaterheatexchangerfromthesurfacetransfersheattothelowboilingpointworkingsubstance-propane,ammonia,etc.,toevaporateandproducesteamThenpushthesteamturbinetodowork.Thedeepcoldseawaterisstillusedasthecoolingmediumofthecondenser.Thissystemdoesnotrequireavacuumpumpandisacycleoftenusedinseawaterthermoelectricpowergeneration.

Origin

Discovery

TheFrenchphysicistAssonval,whofirstproposedtheideaof​​usingthetemperaturedifferenceinseawatertogenerateelectricity,wasastudentofAssonvalin1926.Germanysuccessfullytestedtheseawatertemperaturedifferencetogenerateelectricity.In1930,Claudebuilttheworld'sfirstseawatertemperaturedifferencepowerstationontheCubancoast,andobtained10kWofpower.In1979,theUnitedStatesinstalledaseawatertemperaturedifferencepowergenerationtestbedonanavalbargeinHawaii,withapowergenerationof53.6kW.In1981,Japanbuilta100kWseawatertemperaturedifferencepowergenerationdeviceonNauruIslandintheSouthPacific.In1990,itbuiltamegawatt-levelpowerstationofthesametypeonKagoshima.

Thebiggestdifficultyintheuseoftemperaturedifferenceenergyisthesizeofthetemperaturedifference,lowenergydensity,itsefficiencyisonlyabout3%,andtheheatexchangeareaislarge,andtheconstructioncostishigh.Countriesarestillactivelyexploring.Becausetheseaareasrichinmarinethermalenergyresourcesarefaraway,andaccordingtothelawofthermodynamics,theefficiencyofoceanthermalenergyextractiontechnologyisverylow,sotheamountofenergyavailableisverysmall.Butevenso,thepotentialofoceanthermalenergyisstillconsiderable.Thetemperaturedifferenceinnatureisakindofabundantgreenenergy.Withthedevelopmentofmodernscienceandtechnology,thisnewtypeofenergyisbeingrecognizedandusedbypeople.

Experiment

Theexplorationprocessofhumanbeingsonnaturaltemperaturedifferenceenergyisalong-termandcontinuouseffort.In1933,inalaboratoryinFrance,scientistsusedatemperaturedifferenceof30°Catroomtemperaturetodriveasmallenginetogenerateelectricity,lightingupseveralsmallbulbs,andforthefirsttimeprovedthepossibilityofnaturaltemperaturedifferenceasanenergysource.Inthe1960s,theAlaskaoilpipelineintheUnitedStatesusedcoldweatherconditionstoenhanceheatdissipationandpreventthefoundationsoilfrommeltingandsinking,therebyensuringthesafeoperationofthepipelinesystem.Inspiredbythis,researchersbegantoconductpracticalresearchonnaturaltemperaturedifferenceenergy.In986,afterabout10yearsofexperimentalresearch,Japanbuilttheworld'sfirstcoldstoragewithnaturalcoldenergy.

Practicalapplication

Inpracticalapplications,efficientandcheapenergystorageisthekeytousingnaturaltemperaturedifferenceenergy.Mankindhasdiscoveredavarietyofeffectiveenergystoragebodies.Itcanbedividedintotwomaincategories:oneisorganicmaterialssuchaspropionatealcohol;theotherisinorganicmaterials,suchascompositesaltwater,calciumsulfateandothersubstances.Thesesubstancescanstoretheabsorbednaturaltemperaturedifferenceandreleaseitwhenneeded.UsingtheseenergystoragematerialsintheUnitedStatesandGermany,energy-savingbuildingshavebeenbuiltandputintouse.

Thetemperaturedifferencebetweenthesurfaceanddeeplayersofseawatercanbemorethan20℃,andthisdifferencealsocontainshugeenergy.Accordingtoestimates,thetotalreservescanreach2billionkilowatts.Scientistsareactivelyembarkingonthedevelopmentandutilizationofthermoelectricenergy,andoceanthermoelectricpowergenerationhasenteredtheexperimentalstage.TheUnitedStatesandFrancehavesuccessivelybuiltsmallexperimentalpowerstations.In1990,thethermoelectricpowerstationbuiltbyJapaninKagoshimaisnowreceivingnormalpowersupply.Inaddition,theuseofseawatertemperaturedifferencetogenerateelectricityalsohasthefunctionofdesalinatingseawater.A10millionkilowattthermoelectricpowerstationcanproduce378cubicmetersoffreshwaterperday.Powergenerationthroughoceantemperaturedifferencecanalsoextractrichnutrientsfromdeepseawaterandincreaseoffshorefishing.Theideaof​​usingtemperaturedifferencesasoceanenergysourcesisreallyamazing.Thisistheoceanthermalenergy,alsocalledoceanthermalenergy.Sinceseawaterisamaterialwithalargeheatcapacityandthevolumeoftheoceanissolarge,theamountofheatcontainedintheseawaterishuge.Thisheatenergymainlycomesfromsolarradiation,inadditiontotheheatreleasedfromtheearth'sinteriortothesea;theheatreleasedbyradioactivesubstancesinthesea;theheatgeneratedbythefrictionofoceancurrents,andtheradiantenergyofothercelestialbodies,but99.99%comesfromsolarradiation.Therefore,thethermalenergyofseawatervariesgreatlydependingonthelocationoftheseaarea.Oceanthermalenergyisoneofthesourcesofelectricenergy,whichcanbeconvertedintoelectricenergyof2billionkilowatts.However,in1881,theFrenchscientistDelsonsfirstboldlyproposedtheideaof​​generatingelectricityfromseawaterandwasburiedfornearlyhalfacentury.Itwasnotuntil1926thathisstudentClauderealizedtheteacher'slong-cherishedwish.