某电厂余热锅炉烟气侧低温段受热面的腐蚀积垢原因  

Corrosion and Fouling Reasons of Low Temperature Heating Surface on Flue Gas Side of Waste Heat Boiler in a Power Plant

作　　者：周彬[1] 宗仰炜[1] 葛红花 ZHOU Bin;ZONG Yangwei;GE Honghua(Power Plant of Baoshan Iron&Steel Co.,Ltd.,Shanghai 200941,China;Shanghai Key Laboratory for Electric Power Material Protection and New materials,Shanghai Engineering Research Center of Energy-Saving in Heat Exchange Systems,Shanghai University of Electric Power,Shanghai 200090,China)

机构地区：[1]宝山钢铁股份有限公司电厂,上海201900 [2]上海电力大学上海热交换系统节能工程技术研究中心上海市电力材料防护与新材料重点实验室,上海200090

出　　处：《腐蚀与防护》2021年第2期60-64,69,共6页Corrosion & Protection

摘　　要：某余热锅炉烟气侧低温段的腐蚀积垢现象严重影响了该锅炉的安全运行和传热效率。采用溶液分析、扫描电子显微镜、能谱分析、X-射线衍射等技术,研究分析了该余热锅炉模块6~8烟气侧受热面的固体附着物形貌和组成,分析了受热面腐蚀机理。结果显示:附着物均呈强酸性,主要含Fe、S、O三种元素,主要成分为铁的硫酸盐化合物以及铁的氧化物;根据烟气中SO3含量和水蒸气分压,估算余热锅炉烟气的酸露点温度为150~176℃;模块6和模块8的背风侧表面存在硫酸盐类物质的堆积,显示出硫酸腐蚀特征,其他区域呈酸性湿烟气腐蚀特征,表面出现黄色片状的腐蚀产物。根据该余热锅炉运行现状提出了腐蚀控制建议。The corrosion and fouling phenomenon in the low temperature section of the flue gas side of a waste heat boiler seriously affected the safe operation and heat transfer efficiency of the boiler.The morphology and composition of the solid attachments on gas side heating surface of module 6 to module 8 in the waste heat boiler were studied by solution analysis,scanning electron microscopy,energy dispersive spectrum and X-ray diffraction.The corrosion mechanism of the heating surface was analyzed.The results show that the the solid attachments were strong acidic and mainly contained three elements of Fe,S and O,and the main components were iron sulfate compounds and iron oxides.According to the concentration of SO3 in the flue gas and the partial pressure of water vapor,the acid dew point temperature of the waste heat boiler flue gas was estimated to be 150-176 ℃.The leeward side surface of module 6 and module 8 had been accumulated with sulfate compounds,showing the characteristics of sulfuric acid corrosion.Other areas were characterized by acid wet flue gas corrosion,and yellow flake corrosion products existed on their surfaces.Corrosion control recommendations were proposed based on the current status of the waste heat boiler.

关 键 词：余热锅炉 锅炉用钢 露点腐蚀 酸腐蚀 积垢 

分 类 号：TG174[金属学及工艺—金属表面处理]