埋管流化床内不同粒径颗粒传热行为的欧拉-拉格朗日模拟研究  

Eulerian-Lagrangian Simulation of the Heat Transfer Behavior of Particles with Different Diameters in Fluidized Bed with Immersed Tube

作　　者：赵永志[1] 江茂强[1] 郑津洋[1] 

机构地区：[1]浙江大学化学工程与生物工程学系,浙江杭州310027

出　　处：《高校化学工程学报》2009年第4期559-565,共7页Journal of Chemical Engineering of Chinese Universities

基　　金：国家重点基础研究发展计划(2007CB209706);浙江大学优秀青年教师资助计划资助的项目

摘　　要：将有限元方法、基于非结构化网格的计算流体力学方法与离散单元法结合,建立了CFD-DEM-FEM耦合方法,并在此基础上采用k-ε湍流模型及考虑颗粒间及气固间作用的多向耦合传热模型,对埋管流化床内的流动和传热行为进行了模拟和分析。通过计算结果从微观尺度探讨了埋管流化床内的传热机制,分析了影响床内传热的关键因素,得到了换热管道周围固含率和传热系数的分布规律,考察了颗粒直径对埋管周围传热系数的影响。数值模拟结果与实验数据基本一致,证实了CFD-DEM-FEM耦合方法模拟复杂气固流动和传热的可行性和准确性。A kind of new coupling method, CFD-DEM-FEM method, was established by combining finite element method, computational fluid dynamics based on unstructured mesh, and discrete element method. The flow and heat transfer behaviors in the fluidized bed with an immersed tube were simulated by the programs based on the new method when the κ-ε turbulence model and the multi-way coupling heat transfer model among particles, walls and gas were employed. The micro-scale mechanism of heat transfer in the fluidized bed was explored by the simulation and the critical factors that influence heat transfer between the tube and the bed were discussed. The profiles of average solids fraction and heat transfer coefficient around the tube were obtained and the influences of particle size on the transfer coefficient were revealed by simulations. The computational results agree well with the experiments, which shows that the CFD-DEM-FEM method is feasible and accurate for the simulation of complex gas-solid flow with heat transfer.

关 键 词：埋管流化床 离散单元法 计算流体力学 计算颗粒力学 

分 类 号：TQ018[化学工程] TQ051.13