垃圾焚烧锅炉数值模拟及高温腐蚀研究

CFD Study and High-Temperature Corrosion Study for the Waste Incinerator

针对一台处理量为900 t/d的生活垃圾焚烧炉,用计算流体力学(CFD)的方法模拟了燃烧状况和受热面高温腐蚀情况。采用料层燃烧模型+STAR CCM+耦合的方法模拟了焚烧炉,结果与实际燃烧过程基本一致,说明该方法可以准确地模拟垃圾焚烧锅炉,并为运行参数优化提供依据。建立了受热面高温腐蚀的计算模型,以受热面表面温度为主要影响因素,得到了不同受热面材料在不同温度下的高温腐蚀速率。计算了三级过热器的高温腐蚀情况,结果显示最大腐蚀速率为1.04 mm/a,发生在未覆盖铬镍铁合金层的管束上。优化了焚烧炉的运行工况,提升了焚烧性能,同时降低了三级过热器的高温腐蚀。优化后三级过热器的最大腐蚀速率降低了3%,高腐蚀速率的面积比降低了4%。

This paper aims at a 900 t/d municipal solid waste incinerator,and simulates the combustion condition and high temperature corrosion of the heating surface by CFD method.Firstly,this paper simulates the incinerator by using the bed combustion model+STAR CCM+coupling method,and the results are basically consistent with the actual combustion process,indicating that this method can accurately simulate the waste incineration boiler and provide a basis for the optimization of operating parameters.Secondly,this paper establishes a calculation model of high temperature corrosion of heating surface,taking the surface temperature of heating surface as the main influencing factor.And combined with the specific corrosion rate data of different alloy materials,the high temperature corrosion rate of different heating surface materials at different temperatures is obtained.Then,this paper calculates the high temperature corrosion of the three-stage superheater,and the results show that the maximum corrosion rate is 1.04 mm/a,which occurs in the bundle without chromium-nickel-iron alloy layer.Finally,this paper optimizes the operating conditions of the incinerator,improves the combustion performance,and reduces the high temperature corrosion of the three-stage superheater.The maximum corrosion rate of the three-stage superheater is reduced by 3%,and the area ratio of high corrosion rate is reduced by 4%.