鼓泡流化床内粉煤气化的数值模拟

Numerical simulation of coal gasification in bubbling fluidized bed

将应用欧拉双流体模型对鼓泡气化炉内的气化过程进行研究。摒弃传统颗粒动理学理论中颗粒光滑无旋转的假设,引入颗粒的旋转运动,构建粗糙颗粒动理学理论来封闭双流体模型。基于燃烧理论建立粉煤热解、气化模型以及鼓泡床内气固之间以及气体和气体之间的传热、传质模型。采用该模型进行数值模拟计算,分析床内的气固反应过程,对比实验结果表明粗糙颗粒动理学理论适用于模拟鼓泡床气化炉内的反应。

The gasification behavior of gas and solids in a bubbling fluidized bed gasifier was simulated by Eulerian two-fluid model. Different from the present kinetic theory of granular flow based on the assumption of smooth and elastic during the collision of particles, the rotation of particles was taken into account and the kinetic theory of rough spheres （KTRS） was proposed for the two-fluid model closure. Meanwhile the coal pyrolysis-gasification model based on the combustion theory and the heat and mass transfer model between gas and solid as well as gas and gas in a bubbling fluidized bed were established. By this means, the reaction behavior of gas-solid in the fluidized bed was analyzed. The simulated results agree well with the experimental data, which shows that the kinetic theory of rough spheres can reasonably describe the reaction in a bubbling fluidized bed gasifier.