考虑热解产物组分的煤粉着火燃烧数学模型

建立了球坐标系下考虑煤粉挥发分释放、传热、传质和化学反应全耦合的单颗粒热解、燃烧瞬态数值模型，并对陕西神木烟煤的着火、燃烧特性进行分析.结果表明，单颗粒煤粉的着火始于挥发分，且受氧气扩散速率的控制，挥发分火焰能够到达距颗粒中心约29倍颗粒半径的地方.当煤粉热解完成时，炭粒表面生成的CO被引燃，火焰退回炭粒表面附近而使炭粒快速升温，燃烧进入表面氧化反应控制状态.随着燃烧速率进一步提高，炭粒燃烧又开始受到表面还原反应的控制，火焰再次离开炭粒表面.

Mathematical Model of Pulverized Coal Ignition and Combustion Considering Various Pyrolysis Products

The transient whole-coupling model in a spherical coordinate system on single pulverized coal pyrolysis and combustion was developed, taking into consideration various pyrolysis product release, heat transfer, mass transfer, and chemical reactions. The igntion and combustion characteristics of Shenmu bituminous coal were simulated. The result shows that the ignition of pulverized coal begins from volatiles, and the volatile flame can move rapidly to a position departing from the center of the coal particle by about 29 times radius, due to the limitation of oxygen diffusion; when the coal pyrolysis is completed, the CO generated by surface oxidation reaction has been ignited, the flame returns almost to the coke particle surface, the particle temperature rises abruptly, and the coke combustion is controlled by the surface oxidation reaction; with the combustion rate increasing, the coke combustion begins to be controlled by the surface reducing reaction, and the char flame departs from the particle surface again.