Particle‐scale simulation of the flow and heat transfer behaviors in fluidized bed with immersed tube
Particle‐scale simulation of the flow and heat transfer behaviors in fluidized bed with immersed tube
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DOI：
10.1002/aic.11956
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发表时间：
2009-12
期刊：
影响因子：
3.7
通讯作者：
Yongzhi Zhao;Maoqiang Jiang;Yanlei Liu;Jinyang Zheng
中科院分区：
文献类型：
--
作者：
Yongzhi Zhao;Maoqiang Jiang;Yanlei Liu;Jinyang Zheng
将基于非结构化网格的CFD与DEM相结合，建立了一种新的改进的计算流体力学离散元法（CFD-DEM）。采用k-e湍流模型和颗粒、壁面和气体之间的多路耦合传热模型，采用基于该方法的程序可以模拟复杂几何结构设备内的密集气固两相湍流和换热。采用k-e湍流模型与传热模型相结合的CFD-DEM耦合方法，对含沉管流化床内的流动与换热行为进行了数值模拟。通过模拟结果探讨了流化床传热的微观机理，讨论了影响管床间传热的关键因素。得到了管内平均固相含量和管内周围颗粒管的传热系数分布图，并通过仿真探讨了气速、颗粒直径等流化参数对传热系数的影响。计算结果与实验结果吻合较好，表明本文提出的CFD-DEM方法对于复杂的气固换热流动的模拟是可行和准确的。为进一步模拟流化床中气固两相流的化学反应提供了理论依据。©2009美国化学工程师学会，2009
A kind of new modified computational fluid dynamics-discrete element method (CFD-DEM) method was founded by combining CFD based on unstructured mesh and DEM. The turbulent dense gas–solid two phase flow and the heat transfer in the equipment with complex geometry can be simulated by the programs based on the new method when the k-e turbulence model and the multiway coupling heat transfer model among particles, walls and gas were employed. The new CFD-DEM coupling method that combining k-e turbulence model and heat transfer model, was employed to simulate the flow and the heat transfer behaviors in the fluidized bed with an immersed tube. The microscale mechanism of heat transfer in the fluidized bed was explored by the simulation results and the critical factors that influence the heat transfer between the tube and the bed were discussed. The profiles of average solids fraction and heat transfer coefficient between gas-tube and particle-tube around the tube were obtained and the influences of fluidization parameters such as gas velocity and particle diameter on the transfer coefficient were explored by simulations. The computational results agree well with the experiment, which shows that the new CFD-DEM method is feasible and accurate for the simulation of complex gas–solid flow with heat transfer. And this will improve the farther simulation study of the gas–solid two phase flow with chemical reactions in the fluidized bed. © 2009 American Institute of Chemical Engineers AIChE J, 2009