某电厂水冷壁管泄漏原因分析.pdf

第期锅炉制造NO

2025年01月BOILERMANUFACTURINGJan.2025

某电厂水冷壁管泄漏原因分析

王科芳

（福建大唐国际宁德发电有限责任公司，福建宁德352000）

摘要：对某电厂泄漏水冷壁管取样进行宏观检验、光谱检验、显微组织分析、硬度检验、力学性能试验。结果

表明：爆管首爆口张开较大，爆口边缘有明显变形减薄；首爆管的化学成分符合标准要求；首爆管迎烟气侧组

织为铁素体+长条状珠光体，珠光体未见分散特征，为相变组织，背烟气侧组织为铁素体+珠光体，老化3级，

迎烟气侧硬度值高于背烟气侧。水冷壁管泄漏原因为管子短期过热使得迎烟气侧温度超过Ac，温度，从而造

成管子迎烟气侧组织发生相变，力学性能下降，在蒸汽内压力作用下，温度较高、性能下降更多的迎烟气侧产

生鼓胀变形，管壁变薄，继而发生爆管。

关键词：水冷壁管；相变组织；异物堵塞；短期过热

中图分类号：TM621.2文献标识码：B文章编号：CN23-1249(2025)01-0049-04

LeakageCausesAnalysisofWaterWall-cooledTubeinonePowerPlant

WANGKefang

(FujianDatangInternationalNingdePowerGenerationCo.,Ltd.,Ningde352000,China)

Abstract:Macroscopicinspection,spectralinspection,microstructureanalysis,hardnesstesting,

andmechanicalperformancetestingwereconductedonsamplesofleakingwater-cooledwalltubein

apowerplant.Theburstislargeandthereisobviousdeformationandthinningattheedgeofthe

burst.Thechemicalcompositionofthefirstexplosivetubemeetsthestandardrequirements.The

structureonthefacingsmokesideofthefirstblasttubeiscomposedofferriteandelongatedpearlite,

withnodispersedcharacteristicsofpearlite,whichisaphasetransformedmicrostructure.Thestruc-

tureonthebacksmokesideiscomposedofferriteandpearlitetoo,agedatlevel3.Thehardness

valueonthefacingsmokesideishigherthanthatonthebacksmokeside.Thereasonfortheleak-

ageofthewater-cooledwalltubeisthatthetubeoverheatsforashortperiodoftime,causingthe

temperatureontheupstreamsideofthetubetoexceedtheAcgtemperature,resultinginaphase

transition