运用一种离散单元法(DEM)计算颗粒流体力学(CPFD)对尺寸为900 mm×100 mm×1200 mm的准三维流化床的密相区大颗粒扩散行为进行研究.模拟之前,依照前人实验研究对CPFD方法进行验证,模拟结果与实验结果符合较好,证明了CPFD方法模拟的有效性.模拟中通过注入示踪粒子的方法来研究大颗粒在密相区中的横向扩散系数,研究了流化风速、颗粒直径对颗粒横向扩散系数的影响.模拟结果显示,气泡是引起密相区内颗粒混合的主要因素;随着流化风速增加,颗粒横向扩散系数变大;随着颗粒直径增大,颗粒横向扩散系数减小.%Computational particle fluid dynamics (CPFD), a discrete element method (DEM), was utilized to simulate the lateral diffusion behavior of large solid particles in a 900 mm×100 mm×1200 mm quasi-three dimensional fluidized-bed. Before the simulating, verification had been performed in accordance with previous experimental studies to ensure the reliability of CPFD. The effects of the tracer particle diameter and the fluidizing air velocity on lateral dispersion coefficient of large solid particles in dense zone were investigated by the method of tracer particle. The results showed that the bubble behavior was the major factor of solid mixing in dense zone, which had been confirmed in many literatures. An increased gas velocity or a reduced tracer particle diameter resulted in an increased lateral dispersion coefficient.
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