气相温度随机脉动对生物质颗粒热解的影响

摘要

For exploring the effects of turbulent fluctuation of gas temperature on the instantaneous devolatiliza-tion of biomass particles,the probability density functions(PDF)of instantaneous gas temperature are chosen as double-Delta function,uniform,Beta function,and clipped Gaussian distributions in sequence. The expressions for the random selection of instantaneous gas temperature within a turbulent time scale are provided under different PDFs of instantaneous gas temperature. The devolatilization processes of pine particles with the diameters of 100—300,μm are calculated under different random gas temperature fluctuations. The random fluctuations of gas tem-perature have obvious influences on the devolatilization of particles with different diameters. An increase in the fluctuation intensity of gas temperature will further enhance the effects.%为研究气相温度的湍流脉动对生物质颗粒瞬时热解反应的影响,将气相瞬时温度的概率密度函数(PDF)分别取为双Delta函数分布、均匀分布、Beta函数分布和截尾高斯分布.给出了不同的气相瞬时温度PDF下,在任一湍流时间尺度内随机选取气相瞬时温度的表达式.在不同的气相温度随机脉动方式下,对粒径为100~300,μm的松木颗粒的瞬时热解过程进行了计算.结果表明,气相温度的随机脉动对不同粒径颗粒的热解均有明显的影响,加快了颗粒的质量损失.而气相温度脉动强度的增大会使得这一影响效果更为显著.