某300 MW机组锅炉高温腐蚀原因分析及防范对策

Cause Analysis and Preventive Measures of High Temperature Corrosion for 300 MW Unit Boiler

某300 MW机组锅炉出现高温腐蚀,对锅炉设计参数、煤质参数、运行参数进行分析,锅炉本身设计炉膛热负荷偏高,配套中速直吹式制粉系统不利于煤粉细度控制,且低氮改造后未重新界定设计煤质参数。该锅炉此次出现高温腐蚀的原因为入炉煤煤质发生改变,挥发分大幅降低,受限于锅炉出口NO_(x)排放限制,锅炉主燃烧区严重缺氧燃烧。针对此原因,制定了锅炉高温腐蚀的防范对策,并取得较好效果。

A 300 MW unit boiler has high temperature corrosion.The boiler design parameters,coal quality parameters and operation parameters are analyzed.The designed furnace heat load of the boiler itself is high,the supporting medium speed direct blowing pulver⁃izing system is not conducive to the control of pulverized coal fineness,and the design coal quality parameters are not redefined after low nitrogen transformation.The reason for the high⁃temperature corrosion of the boiler this time is that the quality of the incoming coal has changed,the volatile content has been greatly reduced,limited by the NO_(x) emission limit at the boiler outlet,and the main com⁃bustion area of the boiler is seriously anoxic combustion.For this reason,the preventive countermeasures against high temperature cor⁃rosion of boiler are formulated,and good results are obtained.