在燃煤电厂模拟并联型静电织物过滤器的气流分布(IJISA-V3-N1-5)

I.J.IntelligentSystemsandApplications,2011,1,33-42PublishedOnlineFebruary2011inMECS()Copyright©2011MECSI.J.IntelligentSystemsandApplications,2011,1,33-42SimulationofAirflowDistributionofParallel-TypeElectrostaticFabricFilterinCoal-firedPowerPlantMan-yinHuDept.ofEnvironmentalScienceandEngineering,NorthChinaElectricPowerUniversity,BaodingCity,ChinaEmail:[e-mail]-hongWang,JingZhang,Li-juanYan,KaiCheDept.ofEnvironmentalScienceandEngineering,NorthChinaElectricPowerUniversity,BaodingCity,ChinaEmail:{[e-mail],[e-mail]}AbstractThispaperintroducesthestatusofparallel-typeElectrostaticFabricFilterwasresearched,andthefactorsinfluencingcollectionefficiencywereanalyzedinthispaper.UsingsoftwareGambit,whichalsomeshedthecalculatingregion,athree-dimensionalstructuremodeloftheprecipitatorwasestablished.Andthenthenumericalsimulationoftheairdistributioncharacteristicwascarriedonwiththesoftwareoffluent6.2,whichsetstheboundaryconditions,standardk-ε2-equationmodelandSIMPLEalgorithm;Thendrawthepathlineandcontourchartofthecross-section,obtainedthemeansquaredeviationvalue,analyzedtheairflowdistributionsituationandthereasonsforwhyitsuneven.Bysettinganappropriateopeningratefortheairflowdistributionplatesandcollectionplatestoimprovetheairdistribution.Theresultsshowthattheairflowdistributioncanbeuniformedbyimprovingtheopeningrateofthecollectionplates.ThenumericalsimulationresultismorereasonableandcanbeusedasthereferenceofoptimizingthestructuraldesignofElectrostaticFabricFilter.IndexTermsElectrostaticFabricFilterAirflowdistributionOpeningrateNumericalsimulationINTRODUCTIONWiththedevelopmentofeconomicandimprovementoflivingstandards,airqualitycontrolrequirementsarebecomingstrict,whiletheremovalandperformanceofequipmentisalsoahigherdemand.Electrostaticprecipitatorandbag-hoseprecipitatoraremainlytraditionaldustcollectingequipmentforindustrialfluegaspurificationequipment.Theyhaveplayedaleadingroleinprocessofcontrollingofindustrialdust,butinthenewsituation,itisdifficultforthemtoovercomedeficiencies.ThemaindisadvantagesofESP:itisnoteasytocollectultrafineparticlesbyESP;collectionefficiencyisaffectedbymanyfactors(gastemperature,gasvelocity,dustproperties,sulfur,etc.)[1].Thedisadvantagesofbag-hoseprecipitator:runningresistanceislarge,andsystemresistanceislarge;powerofinduceddraftfanislargeandrunningcostishigh;surfacelifeoffilterbagisshortandreplacementcostishighetc.ElectrostaticFabricFiltercontainstheadvantagesofthetwodustcollector;ittakesadvantageofthemandgainssomeprogress.Itsremovalefficiency,notonlytomeetnewenvironmentalstandards,butalsotoincreasereliability,isoneofthedevelopmentdirectionsoffluegastreatment[2,3].ParallelelectrostaticFabricFilterismadeofESPandfilterdustpart,fluegasafterESPdirectlyintothefabricfilter.Thisapproachhasmanyadvantages:structureiscompact;smallfootprint;thedustwithchargewillnotdisappear;thereisasmalllooseresistancefordustlayeronfilterbag.Butitisverydifficultforairflowdistributiontomeettheoptimalstate,andonlinemaintenancecannotbecompletedbyfabricfilter.Therefore,theuniformityforairflowdistributioninelectrostaticfabricfilterboxbecameahotresearchfor34SimulationofAirflowDistributionofParallel-TypeElectrostaticFabricFilterinCoal-firedPowerPlantCopyright©2011MECSI.J.IntelligentSystemsandApplications,2011,1,33-42experts.Nowdays,themainresearchmethodsaretoestablishstaticprecipitatorexperimentalmodelofcoldairflowdistributiontotestgasvelocityinboxandtogetdifferenttestresultsbychangingdifferentstructure,andthentosearchprogramofuniformityofairflowdistributionbyanalyzingresultscomprehensively[4].Withthedevelopmentofcomputationalfluiddynamics,peopledevelopthecomputationalfluidsoftwarethatareusedtosimulateandcalculate,whichmakesoriginaltestingproceduresimplifyandreducethecost.2008[5],DangXiao-qingcompletedthenumericalanalysisofairflowdistributionofelectricityreformbagfilter,theresultsshowthatnumericalanalysisresults,modeltestandfieldtestresultsareconsistent.NUMERICALSIMULATIONOFFLOWFIELDAModelEstablishmentUsinggambitdrawingtoolstosimplifythestructureofParallelelectrostaticfabricfilter,establishthebasicmodel.AscanbeseenintheFig.1,gasboxentrancelengthandwidthis2.6meters,equippedwiththreeairdistributionplate,dustingroomlengthis17.7meters,widthis9meters,heightis12.15meters,theinternalelectricfieldisdividedintofiveareas,fourbagarea,onemeterapartforeachfieldzone,electricfieldbipolarplatespacing0.8meters,20bagsineachrowissettobagarea,ashhopperandelectrodehaveverylittleeffectontheairflowdistribution,sonotdrawnouthere.Fig.1Three-dimensionalstructuremodelBNumericalMethodandBoundaryConditions1)BoundaryconditionsEntrywassettospeedimportVELOCITY-INLET,exportwassettofreeexportfluidOUTFLOW,Airflowdistributionplate,bipolarplate,andbagweresettoPOROUS-JUMPtheothersweresettothewallno-slipboundarycondition.2)ConditionsandnumericalcalculationmethodTheflowstateoffluewasconsideredassteady-stateisothermalincompressibleflow,refrigerantisthenormaltemperatureair,gasflowratewasQ=316368m3/h;airdens