1000MW超超临界锅炉高温腐蚀分析及对策  

Analysis and Solution of High-temperature Corrosion for a 1000 MW Ultra-supercritical Boiler

作　　者：吕洪坤[1] 童家麟[1] 刘建忠[2] 张明[1] 熊建国[1] 周志军[2] 

机构地区：[1]国网浙江省电力公司电力科学研究院,杭州310014 [2]浙江大学能源清洁利用国家重点实验室,杭州310027

出　　处：《北京工业大学学报》2017年第3期481-488,共8页Journal of Beijing University of Technology

基　　金：国家科技支撑计划资助项目(2015BAA04B03)

摘　　要：为了控制水冷壁高温腐蚀,对某超超临界锅炉贴壁气氛进行了测量,并对腐蚀剥落片做了扫描电镜分析、能谱分析和X射线衍射分析.结果表明:贴壁还原性气氛循环波动是造成水冷壁高温腐蚀的主要原因;燃尽风(OFA)和二层分离式燃尽风(SOFA)之间区域整体上还原性气氛最为强烈,贴壁H2S浓度最高,最易造成高温腐蚀;双切圆墙式燃烧方式易造成前后墙局部H2S浓度偏高;高温腐蚀剥落片外侧为疏松的Fe2O3,内侧为致密的Fe S;负荷变动引起的贴壁气氛氧化-还原交替变动是加剧高温腐蚀程度的重要因素;在锅炉实际运行中,优化配风方式、维持贴壁气氛稳定可以减缓低NOx燃烧锅炉高温腐蚀的进程.In order to control the high-temperature corrosion of water-wall,the pinning atmosphere was measured and the flake pieces were analyzed by SEM,EDS and XRD.The results show that the main reasons of water-wall high-temperature corrosion are cycle-by-cycle variation of reductive atmosphere.The area of most intense of reductive atmosphere and the concentration of H_2S is between OFA and SOFA.The possibility of the high-temperature corrosion of this area is great.Dual tangential circle wall firing can raise the concentration of H_2S at front-wall and back-wall.The outside corrosion product is Fe_2O_3,and on the contrary,the inside one is Fe S.The alternation of the pinning atmospheres from oxidation atmosphere to reductive atmosphere which caused by load was a key factor of the high-temperature corrosion.In actual operation of boiler, optimizing air distribution mode and keeping the pinning atmosphere stabilization can reduce the rate of the high-temperature corrosion to low NO_x combustion boilers.

关 键 词：高温腐蚀 贴壁气氛 理化分析 配风方式 

分 类 号：TK223[动力工程及工程热物理—动力机械及工程]