【标题】超临界机组水冷壁管腐蚀分析与探讨

【Title】Corrosion Analysis and Discussion of water wall tubes in supercritical units

【摘要】针对某超临界火电厂水冷壁管的腐蚀问题进行了相关背景资料调查和取样实验室分析，分析结果表明该火电厂水冷壁管的腐蚀类型为高温硫腐蚀。原因是在燃烧状况不理想的情况下，于上层燃烧器至燃烬风喷口标高区域左右墙形成了还原性气氛，在烟气温度较低且流动性差的管子两侧部位，未被完全燃烧氧化的游离态硫与水冷壁管中的铁反应生成硫化物，铁的硫化物内较多的宏观和微观缺陷为硫和氧向内的渗透和铁离子向外的扩散提供了更多的通道，破坏或强烈地消弱了氧化层对管壁的保护作用，造成了管壁的严重高温硫腐蚀。建议通过燃烧调整解决高温腐蚀问题，之后酌情更换或修复腐蚀严重的水冷壁管；对上层燃烧器至燃烬风喷口标高区域内侧墙进行热喷涂，形成防护层，以阻止高温硫腐蚀的发生；

【Abstract】The corrosion of water wall tubes in a supercritical thermal power plant was investigated and analyzed. The results show that the corrosion types of the water wall tubes in the thermal power plant are high temperature sulfur corrosion. Because of the unideal  combustion  conditions,  the  reducing atmosphere formed at the left and right wall from upper burner to burning ember air nozzle region. The lower flue gas temperature and bad fluidity at the both sides of tubes, resulted in sulfide because of the reaction  between  the  incompletely  combustion oxigation free state sulfur and iron in the tubes. The macro and micro defects of iron sulfides provides more diffusion channels to sulfur and oxygen, and iron ions, thereby, the protection effect of oxide layer on the wall tube had been destroyed and weakened, the serious high temperature sulfur corrosion formed. It is suggested that the high temperature sulfur corrosion should be solved by combustion adjustment, and the serious corrosion water wall tube must be replaced or repaired. The thermal spraying can be used to form the protective layer on the water wall tube and to protect the water wall tube from high temperature sulfur corrosion. 

【关键词】水冷壁；高温腐蚀；硫化物

【Keywords】water wall，high temperature corrosion， sulfide

【作者】

曹海涛	：西安热工研究院有限公司，陕西，西安，710032
张宝柱	：西安热工研究院有限公司，陕西，西安，710032
马红	：西安热工研究院有限公司，陕西，西安，710032

【Author】

Cao Haitao	: Xi’an Thermal Power Research Institute Co.,Ltd.，Shaanxi，Xi’an，710032
Zhang Baozhu	: Xi’an Thermal Power Research Institute Co.,Ltd.，Shaanxi，Xi’an，710032
Ma Hong	: Xi’an Thermal Power Research Institute Co.,Ltd.，Shaanxi，Xi’an，710032

【来源】2015年中国电机工程学会年会

【出版时间】Tue Nov 17 08:00:00 CST 2015