烟气酸露点温度与水套炉受热面尾部低温腐蚀

水套炉受热面尾部烟气腐蚀和堵灰会严重影响其运行的经济性,腐蚀和堵灰的主要原因是H2SO4蒸气在低温受热面上凝结。文章分析了影响烟气酸露点温度的主要因素,概述了国内常用的几种烟气酸露点温度计算方法,应用锅炉受热面低温腐蚀理论,阐述了水套炉受热面尾部低温腐蚀机理,提出了减轻和防止受热面尾部低温腐蚀与堵灰的方法,如减少烟气中的H2O和SO3含量、控制排烟温度和提高受热面尾部金属壁温,可有效减轻和防止水套炉受热面尾部腐蚀。

Acid Dew Point Temperature of Flue Gas and Low Temperature Corrosion at End of Heating Surface of Water Jacket Heater

Corrosion at the end of heating surface of a water jacket heater caused by flue gas and dust blocking can seriously affect heater operation cost.The main reason of corrosion and dust blocking is the coagulation of H2SO4 vapor on the low temperature heating surface of the heater.This paper analyses the main factors affecting acid dew point temperature of flue gas, summarizes several calculation methods of acid dew point temperature of flue gas, illustrates low temperature corrosion mechanism at the end of the heater in terms of low temperature corrosion theory, puts forward some methods to reduce even avoid corrosion at the end of heating surface and dust blocking, such as decreasing H2O and SO3 contents of flue gas, controlling exhausted gas temperature and increasing the temperature of metal plate at the end of heating surface.