ASTM E341-2008 用能量平衡法测量等离子体电弧气体焓的标准实施规程

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【英文标准名称】:StandardPracticeforMeasuringPlasmaArcGasEnthalpybyEnergyBalance
【原文标准名称】:用能量平衡法测量等离子体电弧气体焓的标准实施规程
【标准号】:ASTME341-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E21.08
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:bulkenthalpy;energybalance;gasenthalpy;Bulkenthalpy;Electric-arc-heatedgasstream;Energyanalysis;Plasmaarcgasenthalpy;Totalgasenthalpy
【摘要】:Thepurposeofthispracticeistomeasurethetotalorstagnationgasenthalpyofaplasma-arcgasstreaminwhichnonreactivegasesareheatedbypassagethroughanelectricaldischargedeviceduringcalibrationtestsofthesystem.Theplasmaarcrepresentsoneheatsourcefordeterminingtheperformanceofhightemperaturematerialsundersimulatedhyperthermalconditions.Assuchthetotalorstagnationenthalpyisoneoftheimportantparametersforcorrelatingthebehaviorofablationmaterials.Themostdirectmethodforobtainingameasureoftotalenthalpy,andonewhichcanbeperformedsimultaneouslywitheachmaterialtest,ifdesired,istoperformanenergybalanceonthearcchamber.Inaddition,inmakingtheenergybalance,accuratemeasurementsareneededsincetheefficienciesofsomeplasmageneratorsarelow(aslowas15to20%orlessinwhichcasetheenthalpydependsuponthedifferenceoftwoquantitiesofnearlyequalmagnitude).Therefore,theaccuracyofthemeasurementsoftheprimaryvariablesmustbehigh,allenergylossesmustbecorrectlytakenintoaccount,andsteady-stateconditionsmustexistbothinplasmaperformanceandfluidflow.Inparticularitisnotedthattotalenthalpyasdeterminedbytheenergybalancetechniqueismostusefuliftheplasmageneratordesignminimizescoringeffects.Ifnonuniformityexiststheenthalpydeterminedbyenergybalancegivesonlytheaveragefortheentireplasmastream,whereasthelocalenthalpyexperiencedbyamodelinthecoreofthestreammaybemuchhigher.Moreprecisemethodsareneededtomeasurelocalvariationsintotalenthalpy.1.1Thispracticecoversthemeasurementoftotalgasenthalpyofanelectric-arc-heatedgasstreambymeansofanoverallsystemenergybalance.Thisissometimesreferredtoasabulkenthalpyandrepresentsanaverageenergycontentoftheteststreamwhichmaydifferfromlocalvaluesintheteststream.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:A54
【国际标准分类号】:17_200_10
【页数】:5P.;A4
【正文语种】:英语