炉内煤粉燃烧一维数学模型及其仿真

One-dimensional Mathematical Model and Relevant Simulation for Pulverized Coal Combustion in a Boiler Furnace

为了准确计算炉内煤粉的燃尽率 ,从研究煤粉粒子的燃烧机理入手 ,以炉膛内最复杂的燃烧器区域的煤粉燃烧过程为研究对象 ,通过合理简化煤粉中挥发分和焦炭的燃烧过程 ,建立了炉内煤粉燃烧沿高度方向上的一维宏观模型 ,在模型中考虑了煤粉燃烧过程中氧含量的变化 ,以单个煤粉颗粒燃烧的等密度模型为基础 ,通过多种煤粉粒径的燃烧过程反映煤粉燃烧的整体过程 ,推导出计算炉内煤粉燃尽率的显示公式 ,满足了实时仿真计算的要求。计算结果与实测数据和现有的文献相符 。

The combustion mechanism of pulverized coal particles was studied with pulverized-coal burning process in the most complex combustion zone of a furnace serving an object of research. On this basis a one-dimensional macroscopic model featuring pulverized coal combustion along the furnace height was set up to accurately calculate the burn-off rate of the pulverized coal in the furnace. Through a rational simplification of the combustion process of volatile matter and coke in the pulverized coal the model has taken into account the variation of oxygen content during the pulverized-coal combustion. With the iso-density model of a single pulverized-coal particle combustion serving as a basis an integral process of pulverized coal combustion is reflected through the combustion process of pulverized coal of various particle diameters. Thus, a formula for calculating the burn-off rate of pulverized coal in a furnace has been developed, meeting the requirements of real-time simulation computations. The results of simulation calculations are analyzed and found to be in good agreement with measured data and those given in current literature.