不同负荷下焚烧炉-余热锅炉内垃圾燃烧特性数值模拟

Numerical Simulation of Waste Combustion Characteristics in Incinerator-waste Heat Boiler under Different Loads

为揭示负荷波动对垃圾焚烧电厂垃圾焚烧炉-余热锅炉内垃圾燃烧过程的影响规律,针对某市日处理量700 t/d的垃圾焚烧余热锅炉,采用Fluent和FLIC耦合的方法,研究了不同负荷下炉内垃圾燃烧特性,分别计算了不同负荷下炉内温度场以及各气体的质量分数分布。结果表明:随着负荷的增大,余热锅炉出口平均温度从939.49 K升高到1 039.99 K,出口氧气质量分数从10.03%下降到6.19%,出口二氧化碳质量分数从10.34%升高到13.91%。当垃圾焚烧炉在低负荷条件下运行时,炉膛内部温度相较于高负荷较低,可能会造成污染物排放超标等问题;在高负荷条件下运行时,炉排燃烧段向后推迟,火焰靠近右侧水冷壁,炉膛左右水冷壁之间热偏差较大。

In order to reveal the influence law of load fluctuation on waste combustion process in waste incinerator-waste heat boiler of waste in-cineration power plant,the combustion characteristics of waste in the furnace under different loads were studied for a waste incineration waste heat boiler with a daily capacity of 700 t/d in a city,and the temperature field and mass fraction distribution of each gas in the furnace under different loads were calculated separately by using Fluent and FLIC coupling method.The results show that the average outlet temperature of the waste heat boiler increases from 939.49 K to 1039.99 K,the outlet oxygen mass fraction decreases from 10.03%to 6.19%,and the outlet carbon dioxide mass fraction increases from 10.34%to 13.91%with the increase of load.When the waste incinerator is operated under low load conditions,the internal temperature of the furnace chamber is lower compared to the high load,which may cause problems such as pollu-tant emissions exceeding the standard;when it is operated under high load conditions,the combustion section of the grate is delayed backward,the flame is close to the right water-cooled wall,and the thermal deviation between the left and right water-cooled walls of the furnace chamber is larger.