300MW锅炉低温再热器腐蚀原因分析

The Reasons for the Corrosion of the 300 MW Boiler Low-temperature Reheater

300 MW锅炉低温再热器首次发现斑点状坑腐蚀,腐蚀主要发生在背风面,分布较有规律。电厂采集腐蚀坑中腐蚀产物经化学化验,主要成分为Fe2(SO3)3。从入炉煤质控制分析了发生此种腐蚀的机理,从运行、检修等方向查找了腐蚀发生的原因,并提出了一些指导性建议。

The freckle pit-corrosions occurred for the first time in the low temperature reheater area of the 300 MW boiler in a power plant.Such corrosions mainly existed in the leeward area of the reheater.Through collecting corrosive productions from the corrosion pits and taking chemical inspection,we can confirm the main content of corrosive productions is Fe2（SO3）3.In this paper,the mechanism of the corrosion is analyzed based quality control of the burning coal,the reasons for the corrosions are studied with considerations about the operation and maintenance,and instructive suggestions for improving the performance are put forward.