【摘要】 采用Euler/Euler双流体模型、颗粒动理学方法模拟颗粒相流动,k-ε双方程模型模拟气相湍流流动,同时采用以颗粒团聚物直径为定性尺寸的气?固曳力计算方法,数值模拟高固体流率循环流化床内颗粒的湍动流化特性。计算结果表明,考虑颗粒团聚物影响的模型能准确地反映出床内颗粒湍动流化的宏观规律。颗粒间摩擦应力对固相应力贡献较小。模拟结果获得的空隙率和颗粒浓度分布与实验结果相吻合,同时,预测出颗粒团聚物的分布规律。更多还原

【Abstract】 Flow behavior of gas and particle phases was simulated in a high-density circulating fluidized bed (HDCFB) using the k-ε turbulent model for gas phase, and kinetic theory of granular flow for particles. Drag force between gas phase and solid phase was predicted on the basis of cluster diameter to replace by particle diameter. Numerical results indicate that the characteristics of turbulent fluidization are predicted exactly considering the affect of particle clusters in a HDCFB. Predicted volume fractions of gas and particles agree with experimental results. The effect of frictional force of particles on flow behaviour can be neglected in the simulations. The distribution of cluster sizes was also predicted.更多还原