垃圾炉一次风量对炉床燃烧影响的仿真研究

Simulation of the impact of primary air flow rate on waste combustion on grates

针对垃圾焚烧炉床层内垃圾燃烧过程复杂性及影响垃圾燃烧效率因素多的问题,运用数值仿真方法对某垃圾焚烧炉床层垃圾燃烧进行了模拟,获得了垃圾质量流失速率、水分蒸发速率、挥发分释放速率、焦炭燃烧速率和烟气的温度;并在50~1 000 Nm3/min范围内改变一次风流量,获得了床层质量流失比值、过剩空气系数和烟气中各组分的质量百分比含量。仿真结果显示,一次风流量取值517.47~632.09 Nm3/min时燃烧效率较高;炉排两端区域的一次风流量在50~75 Nm3/min时,可以使垃圾床表面平均温度明显提高,而且还可以提高燃烧效率,同时减少供风总量,节约能源与动力资源。本研究对优化设计垃圾焚烧炉,提高床层内垃圾的燃烧效率有一定参考价值。

The waste combustion in the waste bed and the impacts of the waste burning efficiency are complex.In order to solve this problem,the method of numerical simulation has been adopted to simulate waste combustion,and calculate the mass loss rate,moisture evaporation,volatile release,char burning rate.Used the total flow rate of primary air between 50~1 000 Nm3/min to calculate the mass loss,excess air coefficient of waste bed,components of the gas.Calculated results show that the burning efficiency is higher when the total flow rate of primary air is at 517.47~632.09 Nm3/min.The average surface temperature of waste bed is markedly improved when the primary air flow rate is 50~75 Nm3/min at the both ends of the grates.This can improve the burning efficiency and decrease the total flow rate of primary air to economize energy resources.So there are some reference values for the further optimization of the waste incinerator and improving the burning efficiency.