煤焦反应动力学参数对电站锅炉燃烧影响的数值研究

煤焦作为煤粉燃烧过程中的主要能量来源之一，其燃烧行为对锅炉的安全运行有着举足轻重的作用。文中以某台600MW四角切圆锅炉为对象，针对扩散－动力学控制模型中的不同煤焦反应活化能进行了煤粉燃烧全过程的数值模拟。从模拟结果可以看出，该模型参数不但影响锅炉燃烧的各标量均值，而且影响标量场的分布。当活化能保证煤焦在炉膛内较高燃尽率时，全场标量均值变化不大，仅在分布上有所变化。伴随活化能的升高，煤焦燃尽率降低，各标量全场均值呈单调变化。全场平均温度下降，CO，CO2平均浓度下降，O2平均浓度上升。

Numerical Investigation of Effects of Diffusion-kinetics Parameters to the Comprehensive Combustion Simulation

Energy from char combustion is one of the major energy sources in coal combustion and responsible for the boiler operation security. As one of the char combustion reaction models, diffusion-kinetics limit model is one of the most important and popular model in the combustion simulation, which was employed to describe char combustion behavior mathematically. The parameters in diffusion-kinetics limit model could affect computational fluid dynamics (CFD) results of tangential combustion very well. Different active energy effects are numerically investigated to obtain the influence to the comprehensive combustion simulation. Numerical results show that when kinetic parameters keep char burnout conversion at a high level, averages of scalar change slowly with active energy; but influence their distribution. When these parameter make char conversion drop dramatically, the averages of scalars will changes linearly with active energy; such as temperature decreases with active energy and average mass fraction of CO,CO2 as well, while O2 mass fraction increases with active energy.