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47 个结果
  • 简介:TheDCreactorisanimportantpieceofequipmentforrestrainingloopandripplecurrentsintheinternationalthermonuclearexperimentalreactor(ITER)converterpowersupplysystem.Asthereactorisoperatedatasteadystateof27.5kAandneedstowithstandapeakcurrentof175kA,sothedesignoftheDCreactorusedintheITERconverterpowersupplysystemisnecessary.Anewwater-coolingdry-typeair-corereactorisdesignedinthiswork.Thedetailedstructuralparametersarecalculatedbytheoreticalformulas,andthenthestructureisoptimizedbyelectromagneticsimulationwithANSYS.Finally,thermalanddynamicstabilityanalysesareperformedtoverifythetemperatureandstressataratedcurrentof27.5kAandpulsedcurrentof175kA.TheanalysisresultsshowthatthetemperatureandstressmeettherequirementsoftheITERconverterpowersupplysystem.

  • 标签: 直流电抗器 ITER 转换器 设计 国际热核实验反应堆 干式空心电抗器
  • 简介:AwaterplasmawasgeneratedbyDCarcdischargewithahafniumembeddedrodtypecathodeandanozzle-typeanode.Thedischargecharacteristicswereexaminedbychangingtheoperationparameterofthearccurrent.Thedynamicbehaviorofthearcdischargeledtosignificantfluctuationsinthearcvoltageanditsfrequency.Analysesofthehighspeedimageandthearcvoltagewaveformshowedthatthearcdischargewasintherestrikemodeanditsfrequencyvariedwithinseveraltensofkilohertzaccordingtotheoperatingconditions.Thelargerthermalplasmavolumewasgeneratedbythehigherflowfromtheformingsteamwithahigherrestrikefrequencyinthehigherarccurrentconditions.Inaddition,thecharacteristicsofthewaterplasmajetwereinvestigatedbymeansofopticalemissionspectroscopytoidentifytheabundantradicalsrequiredinanefficientwastetreatmentprocess.

  • 标签: 水等离子体 放电特性 直流电弧 应用 环境 电弧放电
  • 简介:Acomparativestudyoftheneedle-to-liquidplasmainthecontinuousmodewithDCandACexcitationsisdetailedinthispaper.Allplasmasstudiedhereareshowntobeglowdischarges.Thisstudyisbasedonmeasurementsofseveralkeyparameters,includingelectricalenergy,opticalemissionintensitiesofactivespecies,rotationalandvibrationaltemperatures,andtemperaturesoftheneedleandliquidelectrodes.ACplasmascanproduce1.2~5timeshigherexcitedstateactivespeciesthanDCplasmasunderthesamedissipatedpower.ACexcitedliquidplasmashavethehighestenergyutilizationefficiencyamongthethreesystems(ACexcitedplasmas,DCexcitedplasmaswithwateranodeandDCexcitedplasmaswithwatercathode);mostoftheenergyisusedtoproduceusefulspeciesratherthantoheattheelectrodesandplasmas.

  • 标签: 辉光放电等离子体 直流等离子体 激发态 交流 体接触 能量利用效率
  • 简介:AdesignofthemainAC/DCconvertersystemforITERisdescribedandthecon-figurationofthemainAC/DCconvertersispresented.Toreducethereactivepowerabsorbedfromtheconverterunits,themainAC/DCconvertersaredesignedtobeseries-connectedandworkinasequentialmode.Thestructureoftheregulatoroftheconvertersystemisdescribed.AsimulationmodelwasbuiltupforthePSCAD/EMTDCcode,andthedesignwasvalidatedaccordingly.Harmonicanalysisandreactivepowercalculationoftheconvertersunitsarepresented.Theresultsrevealtheadvantageofsequentialcontrolinreducingreactivepowerandharmonics.

  • 标签: 国际热核实验堆 DC变换器 功率转换器 转换系统 AC 设计
  • 简介:Atypeofelectricaldischargecalledslidingdischargewasdevelopedtogenerateplasmaaerodynamicactuationforflowcontrol.Athree-electrodeplasmasheetactuatordrivenbyrepetitivenanosecondpulseswithanegativeDCcomponentwasusedtogenerateslidingdischarge,whichcanbecallednanosecond-pulseslidingdischarge.Thephenomenologyandbehaviouroftheplasmasheetactuatorwereinvestigatedexperimentally.Dischargemorphologyshowsthattheformationofnanosecond-pulseslidingdischargeisdependentonthepeakvalueoftherepetitivenanosecondpulsesandnegativeDCcomponentappliedontheplasmasheetactuator.Comparedtodielectricbarrierdischarge(DBD),theextensionofplasmainnanosecond-pulseslidingdischargeisquasi-diffusive,stable,longerandmoreintensive.TestresultsofparticleimagevelocimetrydemonstratethatthenegativeDCcomponentappliedtoathirdelectrodecouldsignificantlymodifythetopologyoftheflowinducedbynanosecond-pulseDBD.Bodyforceinducedbythenanosecond-pulseslidingdischargecanbeapproximatelyintheorderofmN.BoththemaximumvelocityandthebodyforceinducedbyslidingdischargeincreasesignificantlyascomparedtosingleDBD.Therefore,nanosecond-pulseslidingdischargeisapreferableplasmaaerodynamicactuationgenerationmode,whichisverypromisinginthefieldofaerodynamics.

  • 标签: 等离子体片 纳秒脉冲 直流分量 脉冲驱动 脉冲放电等离子体 执行机构
  • 简介:Inthiswork,wesimulatenumericallythethermaleffectsinnitrogenatatmosphericpressurecausedbyanegativecoronaDCdischargeoflowcurrent.Amathematicalfunctionthatsimulatestheinjectionofthethermaltransferingasisproposed.Thesimulateddischargeisofanegativepointtoplanemasstype,withaninterelectrodedistanceof12mmandasymmetryabouttheaxisofdischarge.Thespatialandtemporalevolutionofneutralsisanalyzedbasedupontheequationsofcontinuity,momentumandenergyinacylindricalgeometry.Forthegeometryofthesystem,theFCT(fluxcorrectedtransport)procedurewasadopted.

  • 标签: 负电晕放电 数值模拟 热效应 几何形状 连续性方程
  • 简介:Dependenceofthecurrent-voltagecharacteristicsofanon-transferredDCcascadedplasmatorchusedfornanoparticlesynthesis,ontheplasmacurrentandtheplasmaargongasflowratearereportedinthispaper.Thepotentialstructureinsidethetorchanditsdependenceontheplasmacurrentandgasflowratearealsoinvestigated.Thearcvoltageisseentoexhibitnegativecharacteristicforacurrentbelow150Aandpositivecharacteristicabovethatcurrentvalue.Thevoltagedropneartheelectrodesisfoundtodecreasewiththeincreaseinplasmacurrent.25%ofthetotalvoltageisdroppednearthecathodeataplasmacurrentof50Aandaargonplasmagasflowrateof10literperminute(LPM),anditdecreasesto12%withthecurrentincreasingto300A,andto17%withagasflowrateof25LPM.Thevariationinthetorchefficiencywiththegasflowrateandplasmacurrentisalsoreported.Theefficiencyofthetorchisfoundtobebetween36%and48%.Inaddition,theplasmagastemperatureatvariouspositionsofthereactorandfordifferentcurrentsandvoltagesaremeasuredbycalorimetricestimationwithaheatbalancetechnique.

  • 标签: 电流电压特性 直流等离子体 等离子体炬 温度测量 级联 等离子体电流
  • 简介:Inresponsetothecurrentimbalancephenomenonanditsharmfulness,acurrentsharingcircuitmodelisbuiltup,whichrevealstheunderlyingcausesforthecurrentimbalancethroughaquantitativeanalysis.Then,afeasibleapproachofimprovement,namelyenlargementofthelengthofconnectionbusbars,isproposed.Aftertheamendment,itcanbeseenthatthecurrentsharingcoefficientisalmostunityunderratedorfaultcurrentconditions.

  • 标签: 电流不平衡 极向场 转换器 PF 特性 共享
  • 简介:Flyashfromamunicipalsolidwasteincinerator(MSWI)withoutpreprocessing(originalflyash,OFA)wasmeltedbyadirectcurrent(DC)plasmaarcfurnacetoinvestigatehowthefeedformsgovernedtheresults.Dioxinsinfluegasfromstackandbag-filterash(BFA)weredetected.ThedistributionofheavymetalsofPb,Cd,As,andCralongthefluegasprocesssystemwasanalyzed.Throughacomparisonoftheresultsfordioxinsandheavymetalsinthisstudyandpreviouswork,carrying-overofflyashparticleswiththefluegasstreamcanbededuced.BasedonthemagneticinductionequationandNavier-Stokesequations,amagnetohydrodynamic(MHD)modelfortheplasmaarcwasdevelopedtodescribetheparticle-carryingeffect.Theresultsindicatethat,a.whenmelted,thefeedformsofMSWIflyashaffecttheresultssignificantly;b.itisnotpreferabletomeltMSWIflyashdirectly,andeffortsshouldbemadetolimitthemasstransferofOFAfromtheplasmafurnace.

  • 标签: 等离子电弧炉 粉煤灰 灰熔融 DC Stokes方程 烟气处理系统
  • 简介:Wedevelopedaone-dimensionalhybridmodeltosimulatetheDC/RFcombineddrivencapacitivelycoupledplasmaforargondischarges.ThenumericalresultsareusedtoanalyzetheinfluenceoftheDCsourceontheplasmadensitydistribution,ionenergydistributions(IEDs)andionangledistributions(IADs)onboththeRFandDCelectrodes.TheincreaseinDCvoltagedrivesmorehigh-energyionstotheelectrodeappliedtotheDCsource,whichmakestheIEDsattheDCelectrodeshifttowardshigherenergy,andthepeaksintheIADsshifttowardssmallangleregions.Atthesametime,italsodecreasestheionenergyattheRFelectrodeandenlargestheincidentanglesoftheions,whichstriketheRFelectrode.

  • 标签: 放电等离子体 直流电源 混合模型 驱动器 射频 模拟
  • 简介:Thispaperproposesanewmethodtopredictthecoronaonsetvoltageforarodplaneairgap,basedonthesupportvectormachine(SVM).BecausetheSVMisnotlimitedbythesize,dimensionandnonlinearityofthesamples,thismethodcanrealizeaccuratepredictionwithfewtrainingdata.Onlyelectricfieldfeaturesarechosenastheinput;nogeometricparameterisincluded.Therefore,theexperimentdataofonekindofelectrodecanbeusedtopredictthecoronaonsetvoltagesofotherelectrodeswithdifferentsizes.Withtheexperimentaldataobtainedbyozonedetectiontechnology,andexperimentaldataprovidedbythereference,theefficiencyoftheproposedmethodisvalidated.Accuratepredictedresultswithanaveragerelativelessthan3%areobtainedwithonly6experimentaldata.

  • 标签: 支持向量机 起始电压 直流电晕 预测 实验数据 气隙
  • 简介:Athreedimensionalsteady-statemagnetohydrodynamicmodelisdevelopedforthearcplasmainaDCsubmergedelectricarcfurnacefortheproductionoffusedMgO.Thearcisgeneratedinasmallsemi-enclosedspaceformedbythegraphiteelectrode,themoltenbathandunmeltedrawmaterials.Themodelisfirstusedtosolveasimilarprobleminasteelmakingfurnace,andthecalculatedresultsarefoundtobeingoodagreementwiththepublishedmeasurements.ThebehaviorofarcswithdifferentarclengthsisalsostudiedinthefurnaceforMgOproduction.Fromthedistributionofthearcpressureonthebathsurfaceitisshownthatthearcplasmaimpingementislargeenoughtocauseacrater-likedepressiononthesurfaceoftheMgObath.Thecirculationofthehightemperatureairundertheelectrodemayenhancethearcefficiency,especiallyforashorterarc.

  • 标签: 电弧等离子体 直流电弧炉 三维数值分析 电力生产 电熔镁 行为
  • 简介:AsinteredTi_(13)Cu_(87)targetwassputteredbyreactivedirectcurrent(DC)magnetronsputteringwithagasmixtureofargon/nitrogenfordifferentsputteringpowers.Titanium-copper-nitrogenthinfilmsweredepositedonSi(111),glassslideandpotassiumbromide(KBr)substrates.Phaseanalysisandstructuralpropertiesoftitanium-copper-nitrogenthinfilmswerestudiedbyX-raydiffraction(XRD).ThechemicalbondingwascharacterizedbyFouriertransforminfrared(FTIR)spectroscopy.TheresultsfromXRDshowthattheobservedphasesarenano-crystallitecubicantirheniumoxide(antiReO_3)structuresoftitaniumdopedCu_3N(Ti:Cu_3N)andnanocrystallitefacecenteredcubic(fcc)structuresofcopper.ScanningelectronmicroscopyandenergydispersiveX-rayspectroscopy(SEM/EDX)wereusedtodeterminethefilmmorphologyandatomictitanium/copperratio,respectively.Thefilmspossesscontinuousandagglomeratedstructurewithanatomictitanium/copperratio(~0.07)belowthatoftheoriginaltarget(~0.15).Thetransmittancespectraofthecompositefilmsweremeasuredintherangeof360nmto1100nm.Filmthickness,refractiveindexandextinctioncoefficientwereextractedfromthemeasuredtransmittanceusingareverseengineeringmethod.Inthevisiblerange,thehigherabsorptioncoefficientofthefilmspreparedatlowersputteringpowerindicatesmorenitrificationincomparisontothosepreparedathighersputteringpower.ThisisconsistentwiththeformationoflargerTi:Cu_3Ncrystallitesatlowersputteringpower.Thedepositionratevs.sputteringpowershowsanabrupttransitionfrommetallicmodetopoisonedmode.Acomplicatedbehaviorofthefilms'resistivityuponsputteringpowerisshown.

  • 标签: 反应溅射沉积 纳米复合薄膜 混合气体 氮气 傅立叶变换红外光谱 磁控
  • 简介:成像板是一种新型的集成式面探测系统,近年来被广泛用于X光,特别是高强的同步辐射X光实验。为改善BSRF的探测条件和水平,最近BSRF购进了一套日本FujiFilm公司生产的BAS-2500成象板探测系统,提出供给广大用户使用。本文介绍了IP的工作原理、特性及应用,并对BSRF的IP探测系统作一简要介绍。

  • 标签: 成象板 面探测器 X射线 工作原理 应用
  • 简介:新型硅P-N结光电超二极管对光于能量响应范围已达到了X射线范围。它具有线性范围大,能量响应范围宽,量子效率高等优点,因而适用X射线之探测。本文介绍了以光电二板管构成同步辐射XAFS探测替代传统的电离室探测组合的研究工作,给出了的探测结构设计,工作原理,实验结果及讨论。

  • 标签: XAFS实验 探测器 同步辐射 硅P-N结光电超二极管 结构设计 工作原理
  • 简介:以流向事故传感为例,运用可靠性技术对核工厂使用的专用传感的失效规律进行分析,对失效分布数据进行了拟合计算,得到了传感的特征寿命,从传感结构方面进行了可靠性分析。

  • 标签: 定时截尾 失效分布 敏感元件
  • 简介:文章对某单位的锆复合板反应设备泄漏原因进行了分析,先后采用两种方法进行泄露修补。对比两次不同的返修方法,认为对安全运行多年的设备,其结构和应力分布已经固化,如果有泄漏,漏点不会很大,但因为设备冷态检查与最终使用工况有较大区别,返修完成前后应模拟工况进行热试,这样才能彻底找到漏点,一次性返修好。对这台设备的返修总结,为类似使用多年的设备返修提供经验。

  • 标签: 锆复合板反应器 泄漏 分析
  • 简介:本文给出了蒸汽发生的设备简化过程和方法,并对蒸汽发生简化模型进行模态分析,将分析结果与设计方模型的模态分析结果进行比较,以验证设计的合理性,结果证明二者基本一致。

  • 标签: 蒸汽发生器 核动力厂 模型分析