对冲燃烧锅炉水冷壁高温腐蚀运行调整

Operation adjustment for high temperature corrosion in water wall of supercritical opposed firing boiler

某超临界机组对冲燃烧锅炉水冷壁存在严重高温腐蚀的现象,这主要因水冷壁壁面附近存在强还原性气氛并伴有H_2S气体产生所致。本文采用单因素轮换法,试验研究了主燃烧器的三次风旋流强度、三次风风量、二次风旋流强度、二次风风量等主要运行参数调整对锅炉水冷壁壁面气氛特性参数H_2S质量浓度的影响规律。结果表明,在锅炉习惯运行方式的基础上,通过适当削弱主燃烧器三次风旋流,同层燃烧器三次风采取"碗式配风",适当增强主燃烧器二次风旋流,增加燃尽风二次风风量,减少燃尽风一次风风量,适当提高运行氧量和一次风速,采取均等配煤方式,降低煤粉细度后,水冷壁侧墙平均H_2S质量浓度由876.5mg/m^3降至352.2mg/m^3,水冷壁壁面气氛得到较大改善,锅炉运行安全性得以提高。

Due to the strong reducing atmosphere and H_2S formation around the water wall of a supercritical opposed firing boiler,serious high temperature corrosion occurred in the water walls.To solve this problem,the single factor alternate method was applied to experimentally investigate the effects of main operating parameters on H_2S concentrations around side water wall.The results show that,on the basis of customary boiler operating condition,after a series of regulations,such as weakening the tertiary air swirl of the main burner appropriately,distributing the tertiary air flow as bowl type,strengthening the secondary air swirl of the main burner appropriately,increasing the swirling air ratio of the OFA burner,reducing direct air ratio of the OFA burner,increasing the running oxygen concentration appropriately,distributing the mills output uniformly,increasing the primary air velocity appropriately,and reducing the coal fineness,the H_2S concentration around the side water wall decreased from 876.5mg/m^3 to 352.2mg/m^3.The atmosphere around the water wall surface was greatly improved,and the security of the boiler operation was enhanced.