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庄家文蒸汽管路的水击简介2蒸汽管路水击简介•水击的定义•造成水击的原因•水击现象的避免和处理3蒸汽管路水击简介水击水击又称水锤,是由于蒸汽或水突然产生冲击力,使锅筒或管道发生音响和震动的一种现象。例如,当输出的蒸汽与管道内的积水相遇时,部分热量被水迅速吸收,使少量蒸汽冷凝成水,体积突然缩小,造成局部真空,因而引起周围介质高速冲击,发生巨大音响和震动。当水击的管道被空气或蒸汽阻塞时,水不能畅通,也会发生音响和振动。4蒸汽管路水击简介5蒸汽管路水击简介PSteamcaneasilycondensewherethereisnoflow.Inthisexample,steamisflowinginthetopline(steamheader)fromlefttoright,butthelowerlegisblocked;thereforethereisnoflowinthelowerleg.Heatiscontinuouslylostthroughpiping,andwithouttheflowofsteamdeliveringheat,thesteaminthelowerlegcoolsandcondenses.6Acloserlookatthecondensatelyinginthelinerevealsthecontentsarelayeredbydifferencesintemperature.However,whenthehotcondensatelayerisdisturbedandthesteamcontactsthesub-cooledcondensate,thesteamrapidlycondenses.Steamisisolatedfromthesub-cooledcondensatebythehotcondensatelayer.Thisallowsthesteamtoslowlycondenseintohotcondensatewhichslowlycoolsintosub-cooledcondensate.蒸汽管路水击简介7PHowever,doingthiswillalmostcertainlyresultinwaterhammer.Possiblysevereenoughtocausethelineorvalvetofail,resultinginpersonnelinjuryordeath.蒸汽管路水击简介8Thefollowingexampleshowswhathappenswhenthisvalveisopenedtodrainthecondensate.蒸汽管路水击简介SteamtoUser9蒸汽管路水击简介Thisrushofsteamflowingabovethecondensate,resultsinawaveofcondensatetoform.10蒸汽管路水击简介11蒸汽管路水击简介12蒸汽管路水击简介13蒸汽管路水击简介Thisformsapocketofsteamsurroundedbycoolercondensate.Thewaveexpandsandformsasealaroundthepipe.14蒸汽管路水击简介Nowifwetakeacloselookatthehotcondensatelayer,you’llnoticeithasbeendisturbedandnolongerinsulatesthesteamfromthesub-cooledcondensate.Sincethewaveofcondensatehassealedtheline,therapidlycondensingsteampullsavacuumAsdiscussedearlier,whensteamcontactssub-cooledcondensate,itrapidlycondenses.SteamHeaderPressureVacuumThisresultsinanimmediateflowofcondensatetowardthevacuumataveryhighrate(100+mph).15蒸汽管路水击简介16蒸汽管路水击简介17蒸汽管路水击简介18蒸汽管路水击简介19蒸汽管路水击简介20蒸汽管路水击简介21蒸汽管路水击简介Sincewaterdoesnotcompress,theslugofcondensateina50psisystemcaneasilyexceed1000psiatthepointofimpact(thevalveyouopened)oranywherealongtheshockwave.Aftertheimpact,areboundingwaveisformed,pushingcondensatebackintheoppositedirection.22蒸汽管路水击简介23蒸汽管路水击简介24蒸汽管路水击简介25蒸汽管路水击简介26蒸汽管路水击简介27蒸汽管路水击简介28蒸汽管路水击简介29蒸汽管路水击简介30蒸汽管路水击简介31蒸汽管路水击简介32蒸汽管路水击简介33蒸汽管路水击简介34蒸汽管路水击简介35蒸汽管路水击简介36蒸汽管路水击简介37蒸汽管路水击简介38蒸汽管路水击简介39蒸汽管路水击简介40蒸汽管路水击简介41蒸汽管路水击简介42蒸汽管路水击简介43蒸汽管路水击简介44蒸汽管路水击简介45蒸汽管路水击简介46蒸汽管路水击简介PFirst,checkandseeifthelinehassub-cooledcondensate.Thisisbestdonebyusingatemperaturegun.Ifthebottomofthelineismorethan40°Fcoolerthanthesteam,youhavesub-cooledcondensate.Next,sincethemagnitudeofcondensation-inducedwaterhammerisdirectlyrelatedtothedifferenceinup-streampressureandthevacuumcreatedbythesub-cooledcondensate,weneedtoreducethisdifferentialpressure.Sohowdoyouremovethecondensatefromthelowerlegwithoutwaterhammer?Also,withthesteamisolatedfromtheline,thevaporspaceleftwhendrainingthesucondensatewillpullairfromtheatmosphere.Thesteamcontactingsub-cooledcondensateisthecauseofthewaterhammer.Withairtakingtheplaceofthesteam,thisdrivingforceiseliminated.Inotherwords,isolatingthelinefromthesteamheaderanddepressuringittotheatmospherewillreducethediffierentialpressuretoalmostzero.47蒸汽管路水击简介P48蒸汽管路水击简介P49蒸汽管路水击简介P50蒸汽管路水击简介P51蒸汽管路水击简介P52蒸汽管路水击简介PNext,openableederatthehighestpointofthelinetodepressureline.53蒸汽管路水击简介P54蒸汽管路水击简介P55蒸汽管路水击简介P56蒸汽管路水击简介P57蒸汽管路水击简介P58蒸汽管路水击简介PNowthatthelineisabout0psig,ifavacuumisformedbythecontactofsub-cooledcondensateandsteam,thestrengthofanywaterhammerwillbeminimal.59蒸汽管路水击简介P60蒸汽管路水击简介P61蒸汽管路水击简介P62蒸汽管路水击简介P63蒸汽管路水击简介P64蒸汽管路水击简介P65蒸汽管路水击简介P66蒸汽管路水击简介P67蒸汽管路水击简介P68蒸汽管路水击简介P69蒸汽管路水击简介P70蒸汽管路水击简介PNowthatthelineisdrained,steamcanbeintroducedtowarmtheline.71蒸汽管路水击简介P72蒸汽管路水击简介P73蒸汽管路水击简介P74蒸汽管路水击简介POncethelineishasbeenheatedforthedesignatedtime,thelinecanbeplacedbackinservice.75蒸汽管路水击简介P76蒸汽管路水击简介P77蒸汽管路水击简介P78蒸汽管路水击简介P79蒸汽管路水击简介P80蒸汽管路水击简介P81蒸汽管路水击简介蒸汽管道内水击的原因:•在送汽前未进行疏水和暖管。•送汽时主汽阀开启过快或过大。•锅炉负荷增加过急或发生满水、汽水共腾等事故,蒸汽严重带水进入管道。82蒸汽管路水击简介蒸汽管道内水击的处理:•开启过热器集箱和蒸汽管道上的疏水阀,进行疏水。•锅筒水位过高时,应适当排污,保持正常水位。•加强水处理工作,保证给水和锅水质量,避免汽水共腾。83蒸汽管路水击简介To所PPE是我们最后一道保护防线。工作之前确保良好的准备,所有的烧伤和烫伤都是可以避免的。温馨提示:
本文标题:蒸汽管道水击简介
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