氫的物理化學(xué)性質(zhì)Physicalandchemicalpropertiesofhydrogen《儲能技術(shù)概論》《EnergyStorageTechnology》主講教師：Instructor:

氫的物理化學(xué)性質(zhì)PhysicalandchemicalpropertiesofhydrogenCONTENTS氫的物理特性Physicalpropertiesofhydrogen01PART氫的化學(xué)特性Chemicalpropertiesofhydrogen02PART目錄氫的物理特性PhysicalpropertiesofhydrogenPART01一、氫的物理特性Physicalpropertiesofhydrogen（1）基本物理參數(shù)Basicphysicalparameters氫的物理性質(zhì)Physicalpropertiesofhydrogen（2）擴散性和滲透性Diffusionandpermeability（3）熱學(xué)性質(zhì)Thermalproperties一、氫的物理特性Physicalpropertiesofhydrogen（一）氫的基本物理參數(shù)Basicphysicalparametersofhydrogen狀態(tài)與密度Stateanddensity在標準狀況下，氫為無色、無味、無臭的氣體。其密度極低，僅為0.0899g/L，約為空氣密度的十四分之一，這使得氫氣在儲存和運輸過程中需要特殊的容器和方式。Understandardconditions,hydrogenisacolorless,odorlessgas.Itsdensityisextremelylow,only0.0899g/L,aboutone-fourteenthofthedensityofair,whichmakeshydrogenstorageandtransportationrequirespecialcontainersandmethods.熔點與沸點Meltingpointandboilingpoint氫的熔點為-259.14℃，沸點為-252.87℃。常溫常壓下以氣態(tài)氫存在，液氫的密度為70.8kg/m3，相比氣態(tài)氫，液化后提高了單位體積的能量存儲密度，有利于大規(guī)模的氫儲能應(yīng)用。Themeltingpointofhydrogenis-259.14℃,andtheboilingpointis-252.87℃.Hydrogenexistsingaseousstateatroomtemperatureandatmosphericpressure,andthedensityofliquidhydrogenis70.8kg/m3.Comparedwithgaseoushydrogen,theenergystoragedensityperunitvolumeisincreasedafterliquefaction,whichisconducivetolarge-scalehydrogenenergystorageapplications.一、氫的物理特性Physicalpropertiesofhydrogen（一）氫的基本物理參數(shù)Basicphysicalparametersofhydrogen臨界參數(shù)Criticalparameters氫的臨界溫度為-239.9℃，臨界壓力為1.29MPa。氫的臨界溫度極低，這增加了液化的難度，但也意味著在高于臨界溫度時，氫氣始終保持氣態(tài)，便于在某些需要氣態(tài)氫參與的儲能過程中使用。Thecriticaltemperatureofhydrogenis-239.9℃andthecriticalpressureis1.29MPa.Theextremelylowcriticaltemperatureofhydrogenincreasesthedifficultyofliquefaction,butitalsomeansthathydrogenremainsinagasstateabovethecriticaltemperature,whichfacilitatestheuseofgaseoushydrogeninsomeenergystorageprocesses.一、氫的物理特性Physicalpropertiesofhydrogen（二）擴散性與滲透性Diffusionandpermeability01.高擴散性Highdiffusivity氫具有極高的擴散系數(shù)，在空氣中的擴散系數(shù)約為0.611cm2/s。在氫儲能系統(tǒng)的設(shè)計中，積極方面在于，當氫氣發(fā)生少量泄漏時，它能快速分散，降低局部氫氣濃度，減少爆炸風險。然而，高擴散性也增加了氫氣泄漏的可能性，對容器的密封性要求極高。Hydrogenexhibitsanexceptionallyhighdiffusioncoefficient,withaspecificdiffusionrateofapproximately0.611cm2/sinair.Inhydrogenenergystoragesystemdesign,thischaracteristicoffersadualadvantage:whenminorleaksoccur,thegasrapidlydispersestoreducelocalizedconcentrationsandminimizeexplosionrisks.However,itshighdiffusivityalsoincreasesleakagepotential,requiringextremelystringentsealingstandardsforcontainmentvessels.一、氫的物理特性Physicalpropertiesofhydrogen（二）擴散性與滲透性Diffusionandpermeability02.強滲透性Strongpermeability氫原子半徑極小，僅為0.037nm。能夠透過許多常見的材料，如橡膠、塑料，甚至金屬。長期與氫氣接觸，材料可能會發(fā)生氫脆現(xiàn)象，導(dǎo)致材料的力學(xué)性能下降，如韌性和強度降低。Theradiusofhydrogenatomsisverysmall,only0.037nm.Itcanpassthroughmanycommonmaterials,suchasrubber,plastic,andevenmetal.Long-termcontactwithhydrogenmaycausehydrogenembrittlementofthematerial,resultinginadeclineinmechanicalproperties,suchastoughnessandstrength.一、氫的物理特性Physicalpropertiesofhydrogen（三）熱學(xué)性質(zhì)Thermalproperties比熱容Specificheatcapacity氫的比熱容較大，在常溫常壓下，定壓比熱容約為14.307kJ/(kg·K)。溫度變化相對較小。Hydrogenhasalargespecificheatcapacity,atroomtemperatureandpressure,thespecificheatcapacityatconstantpressureisabout14.307kJ/(kg·K).Thetemperaturechangeisrelativelysmall.01導(dǎo)熱性Thermalconductivity氫的導(dǎo)熱率在所有氣體中名列前茅，在0℃時，其導(dǎo)熱率為0.1815W/(m·K)瓦每米每開，約為空氣導(dǎo)熱率的7倍。Hydrogenisoneofthebestthermalconductorsofallgases.At0℃,itsthermalconductivityis0.1815W/(m·K)wattpermeterperkilometer,aboutseventimesthatofair.02氫的化學(xué)特性ChemicalpropertiesofhydrogenPART02二、氫的化學(xué)特性

Chemicalpropertiesofhydrogen（1）可燃性與燃燒特性Combustibilityandcombustioncharacteristics（2）還原性Reducingpower（3）與金屬相互作用Interactionwithmetal二、氫的化學(xué)特性

Chemicalpropertiesofhydrogen（一）可燃性與燃燒特性Combustibilityandcombustioncharacteristics01.燃燒反應(yīng)Combustionreaction氫氣具有高度可燃性，在空氣中，氫氣與氧氣發(fā)生燃燒反應(yīng)。這一反應(yīng)釋放出大量的熱，氫氣的燃燒熱為285.8KJ/mol，是同質(zhì)量汽油燃燒熱的3倍。Hydrogenishighlyflammableandburnswithoxygeninair.Thisreactionreleasesalargeamountofheat,andthecombustionheatofhydrogenis285.8KJ/mol,whichisthreetimesthatofgasolineburningwiththesamemass.02.燃燒特性Combustioncharacteristics氫氣在空氣中的燃燒極限范圍較寬，體積分數(shù)為4.0%-75.6%。在氫儲能系統(tǒng)的設(shè)計和運行中，必須嚴格控制氫氣濃度，確保其在安全范圍內(nèi)。氫氣的燃燒速度極快，在常壓下，氫氣與氧氣的預(yù)混火焰燃燒速度可達2.7m/s。Hydrogenhasawidecombustionlimitrangeinair,withavolumefractionof4.0%to75.6%.Inthedesignandoperationofhydrogenenergystoragesystems,itisessentialtostrictlycontrolhydrogenconcentrationwithinsafelimits.Hydrogenburnsextremelyrapidly;underatmosphericpressure,pre-mixedhydrogen-oxygenflamescanreachaburningspeedof2.7meterspersecond.二、氫的化學(xué)特性

Chemicalpropertiesofhydrogen（二）氫的還原性ReducingPowerofHydrogen氫作為還原劑，將其他物質(zhì)還原。例如，在冶金工業(yè)中，氫氣可用于還原金屬氧化物，通過這種方式可以制備高純度的金屬。在氫儲能領(lǐng)域，某些儲能技術(shù)利用氫氣的還原性來實現(xiàn)能量的存儲和轉(zhuǎn)換。Asareducingagent,hydrogencanreduceothersubstances.Forinstance,inthemetallurgicalindustry,hydrogenisusedtoreducemetaloxides,enablingtheproductionofhigh-puritymetals.Inhydrogenenergystorageapplications,specifictechnologiesleveragehydrogensreducingpropertiesforenergystorageandconversionprocesses.氫氣不僅能還原金屬氧化物，還能與許多非金屬氧化物發(fā)生反應(yīng)。CO?+H?=CO+H2O。

Hydrogencannotonlyreducemetaloxides,butalsoreactwithmanynon-metallicoxides.CO?+H?=CO+H2O二、氫的化學(xué)特性

Chemicalpropertiesofhydrogen（三）氫與金屬的相互作用Interactionbetweenhydrogenandmetal許多金屬能夠與氫氣發(fā)生反應(yīng)，形成金屬氫化物。Mg+H2=MgH2。Manymetalsreactwithhydrogentoformmetalhydrides.Mg+H2=MgH2金屬氫化物具有較高的儲氫容量，在氫儲能領(lǐng)域，金屬氫化物儲氫被視為一種有潛力的固態(tài)儲氫方式。Metallichydrideshavehighhydrogenstoragecapacity.Inthefieldofhydrogenenergystorage,metallichydridehydrogenstorageisregardedasapotentialsolidstatehydrogenstoragemethod.SUMMARY小結(jié)01理解氫的物理化學(xué)性質(zhì)，對于優(yōu)化氫儲能系統(tǒng)的各個環(huán)節(jié)，從儲存、運輸?shù)侥芰哭D(zhuǎn)換與利用，以及提升系統(tǒng)的安全性和可靠性都具有重要意義Understandingthephysicalandchemicalpropertiesofhydrogenisofgreatsignificanceforoptimizingallaspectsofhydrogenenergystoragesystem,fromstorageandtransportationtoenergyconversionandutil