Research of the Gas-solid Flow Character Based on the DEM Method  

作　　者：Xueyao Wang and Yunhan Xiao Research Center for Clean Energy and Power,Chinese Academy of Sciences Key Laboratory of Advanced Energy and Power,Chinese Academy of Sciences (Institute of Engineering Thermophysics),Beijing,100190,China 

出　　处：《Journal of Thermal Science》2011年第6期521-526,共6页热科学学报（英文版）

基　　金：Supported by National Natural Science Foundation of China(51006106);National High Technology Research and Development of China 863 Program(2006AA05A103)

摘　　要：Numerical simulation of gas-solid flow behaviors in a rectangular fluidized bed is carried out three dimensionally by the discrete element method (DEM).Euler method and Lagrange method are employed to deal with the gas phase and solid phase respectively.The collided force among particles,striking force between particle and wall,drag force,gravity,Magnus lift force and Saffman lift force are considered when establishing the mathematic models.Soft-sphere model is used to describe the collision of particles.In addition,the Euler method is also used for modeling the solid phase to compare with the results of DEM.The flow patterns,particle mean velocities,particles' diffusion and pressure drop of the bed under typical operating conditions are obtained.The results show that the DEM method can describe the detailed information among particles,while the Euler-Euler method cannot capture the micro-scale character.No matter which method is used,the diffusion of particles increases with the increase of gas velocity.But the gathering and crushing of particles cannot be simulated,so the energy loss of particles' collision cannot be calculated and the diffusion by using the Euler-Euler method is larger.In addition,it is shown by DEM method,with strengthening of the carrying capacity,more and more particles can be schlepped upward and the dense suspension upflow pattern can be formed.However,the results given by the Euler-Euler method are not consistent with the real situation.

关 键 词：DEM gas-solid flow numerical simulation 

分 类 号：TK124[动力工程及工程热物理—工程热物理]