气相温度脉动对木材颗粒热解影响的数值模拟

NUMERICAL SIMULATION OF EFFECTS OF GAS TEMPERATURE FLUCTUATION ON PYROLYSIS OF WOOD PARTICLES

采用三平行反应热解模型，耦合颗粒能量方程和质量方程，得到粒径为100～500μm的木材颗粒在有温度脉动的热气流中热解时颗粒瞬时质量的变化过程。计算结果表明：气相温度脉动可加快木材颗粒瞬时质量下降即挥发分释放的速率，并使得产物中挥发分增加，焦炭减少；随着脉动强度增大，气相温度脉动的影响增强；当气相温度脉动强度相同时，计算结果对气相瞬时温度的选取方式不敏感。

The three parallel reaction model was used for the pyrolysis of wood particles. It couples with the particle energy and mass equations. The instantaneous mass variations of wood particles with diameters of 100-500 μm were calculated during their pyrolysis in a hot gas with fluctuating temperature. The gas temperature fluctuation leads to faster mass loss of the particles and faster devolatilization rates, more volatile yield, and less char production. The effects are enhanced by increasing the fluctuation amplitude of the gas temperature. When the fluctuation amplitude of the gas temperature maintains the same, the approach to choose the instantaneous gas temperature has little influences on the calculated results.