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1、600MW机组凝结水含氧量超标的危害和预防600MWunitscondensateoxygencontentofthehazardsofexcessiveandprevention１Condensateofdissolvedoxygenisoneofthemainindicatorsofthechemicalsupervision，600MWunitscondensatedissolvedoxygencontenthigherdissolvedoxygen，becausealotofexcessiveorlong-termfailure,Itw
2、illacceleratethecondensatepipelineandequipmentcorrosion,andmakecondensatcontainsironoxideions,causinggalvaniccorrosion，Heattransferdeterioration,untiltheoccurrenceofboilertube,andcrewsafetyandeconomicoperationofunits.凝结水溶解氧是化学监督的主要指标之一,特别是600M机组对凝结水溶解氧含量有更高的要求.因为溶解氧大幅度超标或长期不
3、合格，会加速凝结水管道及设备的腐蚀，并使凝结水中含有氧化铁离子，引起电化腐蚀，使传热恶化，直至发生锅炉爆管，严重威胁机组安全、经济运行。凝结水溶解氧存在的原因：1.真空系统不严密，进入凝结器的漏量大；2.有溶解氧含量较高的补水或回收水大量进入凝结器；Condensateofdissolvedoxygenreasonsfortheexistence:1.vacuumsystemisnottight,alotofairtoenterthecondenser;2.higherlevelsofdissolvedoxygenreplenishwatero
4、rrecycledwaterenterthecondenser针对上述原因，从以下方面进行防范和处理：Fortheabovereasons,fromthefollowingaspectspreventandtreatment:运行中真空系统的查漏以氦介质检漏为主。方法是在运行真空泵出口布置氦介质检漏装置，利用专用的喷枪在所有负压系统的阀门、法兰、管道焊缝、排大气口等处喷氦气，然后观察1-2分钟，如果检测点有泄露，检漏装置就会发出报警，泄漏量越大，报警数值就越大，即使很微量的泄露，也能检测出来。并且这种方法灵活，不受时间限制，消除漏点后随时可以检
5、测溶解氧的变化。缺点是工作量大，耗时长。1.真空系统的查漏1.vacuumsystemleakrunningvacuumsystemleakismainlyheliummediumLeak.runningvacuumpumpoutletlayouttheheliummediumleakdetectiondevices,withadedicatedgunsprayheliumtoallnegativepressuresystemvalves,flanges,pipeweldsandexclusiveatmospheremouthetc,theno
6、bservedfor1-2minutes,ifitdetectssomeleakage,andtheleakdetectiondevicewillalarm,thegreatertheamountofleakage,thegreaterthealarmvalue,evenaverysmallamountofleakagecanbedetected.themethodisflexible,withouttimelimit,aftereliminatetheleak，atanytimethechangeofdissolvedoxygencanbed
7、etected.Thedrawbackisthelargeamountofwork,time-consuminglong灌水查漏。方法是：凝结器灌水至末级叶片下100mm高度，然后查漏处理。需要注意的是灌水过程中有专人监视水位，防止水位过高进入汽轮机。但这种方法必须停机后才能进行。Condenserirrigationtothelaststagebladesunder100mmheight,thenleaktohandle.Shouldbenotedthatthereissomeonetomonitorthewaterlevel,inorder
8、topreventthehighwaterlevelentertheturbineintheirrigationprocess.However,thi
