燃用生物质锅炉末级过热器管腐蚀原因分析  

Corrosion of TP347H final superheater on a biomass boiler

作　　者：刘蕊[1] 岳增武[1] 

机构地区：[1]山东电力研究院,山东济南250002

出　　处：《热力发电》2013年第2期98-100,105,共4页Thermal Power Generation

摘　　要：某台燃用生物质锅炉在累计运行4 000h后,末级过热器管(材质为TP347H)外壁发生了较严重的腐蚀,对腐蚀部位进行显微组织、能谱成分及X射线衍射分析。结果表明,末级过热器管存在均匀腐蚀及晶界腐蚀;腐蚀层主要含Cl、K离子而Cr含量相对较低;晶界腐蚀产物主要为Cr和Fe的氧化物,其中Cr含量较高。分析认为生物质中的氯离子是导致管外壁快速腐蚀的主要原因,而碱金属与Fe等其它元素形成的低熔点共晶体促进了腐蚀过程。对此,提出去除燃料中的部分K和Cl,将生物质与煤混燃等措施。The third stage superheater(using TP347H steel) of a biomass fired boiler suffered serious surface corrosion after being in service for 4 000 hours.Microstructure analysis,energy spectrum analysis and X-Ray diffraction analysis were conducted on the corroded tubes.The results showed that,uniform corrosion and grain boundary attack both occurred.In corrosion layer there were mainly chlorine and potassium compounds while the chromium content was low.The grain boundary corrosion products mainly consisted of Cr and Fe oxides,among which the Cr content was higher.The chlorine in biomass was considered as the major factor that causing the rapid corrosion on tube surface,and the eutectic with low melting point formed by alkali metal and Fe and other elements enhanced the corrosion.Thus,some measures like cofiring the biomass with coals were proposed to reduce the corrosion rate of tubes in biomass boiler.

关 键 词：锅炉 过热器 腐蚀 TP347H 碱金属 生物质 氯离子 

分 类 号：TK223.3+2[动力工程及工程热物理—动力机械及工程]