蒸汽管道水击简介ppt课件.ppt

《蒸汽管道水击简介ppt课件.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、蒸汽管路的水击简介1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2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。3蒸汽管路水击简介水击的冲击力可超过1000psi.4蒸汽管路水击简介600psig/41bar-750°F/399°CSteamcaneasilyconden

2、sewherethereisnoflow.Inthisexample,steamisflowinginthetopline(steamheader)fromlefttoright,butthelowerlegisblocked;thereforethereisnoflowinthelowerleg.Heatiscontinuouslylostthroughpiping,andwithouttheflowofsteamdeliveringheat,thesteaminthelowerlegcoolsandcondenses.5蒸汽管路水击简介SteamHotC

3、ondensateSub-cooledCondensate620°F540°F580°FAcloserlookatthecondensatelyinginthelinerevealsthecontentsarelayeredbydifferencesintemperature.However,whenthehotcondensatelayerisdisturbedandthesteamcontactsthesub-cooledcondensate,thesteamrapidlycondenses.Steamisisolatedfromthesub-coole

4、dcondensatebythehotcondensatelayer.Thisallowsthesteamtoslowlycondenseintohotcondensatewhichslowlycoolsintosub-cooledcondensate.6蒸汽管路水击简介However,doingthiswillalmostcertainlyresultinwaterhammer.Possiblysevereenoughtocausethelineorvalvetofail,resultinginpersonnelinjuryordeath.7蒸汽管路水击简

5、介Thefollowingexampleshowswhathappenswhenthisvalveisopenedtodrainthecondensate.SteamtoUser8蒸汽管路水击简介Thisrushofsteamflowingabovethecondensate,resultsinawaveofcondensatetoform.9蒸汽管路水击简介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Thisformsapocketofsteamsurroundedbycoolercondensate.Thewaveexpandsandfo

6、rmsasealaroundthepipe.13蒸汽管路水击简介Nowifwetakeacloselookatthehotcondensatelayer,you’llnoticeithasbeendisturbedandnolongerinsulatesthesteamfromthesub-cooledcondensate.Sincethewaveofcondensatehassealedtheline,therapidlycondensingsteampullsavacuumAsdiscussedearlier,whensteamcontactssub-c

7、ooledcondensate,itrapidlycondenses.SteamHeaderPressureVacuumThisresultsinanimmediateflowofcondensatetowardthevacuumataveryhighrate(100+mph).14蒸汽管路水击简介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Sincewaterdoesnotcompress,theslugofcondensateina50psisystemcaneasilyexce

8、ed1000psiatthepointofimpac