煤燃烧过程中一次破碎的影响因素分析

本文从理论上分析了煤燃烧过程中的一次破碎过程,同时考虑热应力和内部压力积聚的作用,建立了简化的一次破碎模型,通过此模型分析了煤颗粒的粒径、炉膛温度、炉膛对煤颗粒的传热系数、煤颗粒的热扩散系数、煤颗粒脱挥发分的化学动力学参数、煤中对流孔直径、煤的孔隙率、挥发分的粘性系数以及挥发分含量这9个参数对燃烧过程中煤颗粒一次破碎的影响,分析所得结果与近年来报道的实验结论基本保持一致。

SIGNIFICANT FACTORS AFFECTING THE PRIMARY FRAGMENTATION OF COAL PARTICLES DURING COAL COMBUSTION

In this paper, the primary fragmentation of coal particles caused by thermal stresses and internal pressure during coal combustion was analyzed theoretically. A simple model of the primary fragmentation of coal particles was developed. The model was used to evaluate significant variables affecting the primary fragmentation of coal particles. Nine factors, say, coal particle diameter, furnace temperature, heat transfer coefficient from the furnace to the surface of coal particle, thermal diffusivity, the kinetics of devolatilization reaction, the diameter of coal convective pore, the porosity of coal, the viscosity of volatile matter and the content of volatile matter are considered and analyzed. The results are consisted with the recent experimental data.