Abstract: Gas-solid flow behavior of a 65 t/h high-low bed CFB has been simulated using Eulerian-Eulerian model （EEM） with kinetic theory of granular flow by Fluent，a commercial CFD software. RNG k-ε per phase turbulence model，Gidaspow drag model and Schiller-naumann drag model were adopted to evaluate the governing equations. The comparative study with regard to single size particle model and different particle model based on EEM was performed. The diameter of particles in single size particle model was unique，while three kinds of diameter in different particle models were set to achieve the size distribution. Gas-solid flow characteristics were obtained for solid velocity，pressure，solid volume fraction. The calculated pressure was compared with the measured data. The results showed that the Eulerian-Eulerian two-phase model can predict preferably the gas-solid flow behavior. The conclusion of numerical study provided theory basis for the optimization design，operation and large-scale of high-low bed CFB.

Key words: high-low bed CFB, Eulerian-Eulerian model, kinetic theory of granular flow, gas-solid flow characteristics

摘要： 对一台65 t/h高低差速循环流化床炉内流动特性进行二维数值模拟。采用基于颗粒动力学理论的欧拉双流体模型来描述气固流动，湍流模型、气固曳力模型和不同粒径颗粒间曳力模型分别采用RNG k-ε per phase模型、Gidaspow模型和Schiller-naumann模型，并应用商业计算流体力学软件Fluent进行数值计算，得到炉内颗粒速度分布、压力分布和颗粒浓度分布，并将压力分布与实测值进行对比。在欧拉双流体模型中分别采用单粒径固相模型和多粒径固相模型，并对模拟结果进行对比分析。结果表明，单粒径固相模型能够较好预测高低差速循环流化床炉内流动特性，为其优化设计、运行及大型化提供了理论依据。

关键词: 高低差速循环流化床, 欧拉双流体模型, 颗粒动力学理论, 气固流动特性