交互循环双流化床的气/固运动三维数值模拟

Three-Dimensional Simulation of Gas-Solid Flow in a Cross Dual Circulation Fluidized Bed

双流化床作为一种具有燃料高效利用和分级转化优势的新型能源技术,其内部的物理结构和流动特性复杂。本文以交互循环双流化床为研究对象建立了三维数值模型,采用了基于欧拉-拉格朗日方法的气固两相流数值模拟方法,气相采用大涡湍流模型(LES),颗粒相采用多相流网格质点群(MP-PIC)方法.实现了三维双流化床全场气固循环、交互和连续稳定运行。在与实验验证的基础上,通过模拟,研究了不同的操作条件对流动结构、颗粒分布等流体力学特性的影响,获得了一系列实验难以得到的规律。

The dual circulation fluidized bed,an emerging technology of energy utilization and classification conversion,has confoundedly complicated physical structure and hydrodynamics.This paper built a three-dimensional numerical model based on a cross dual circulation fluidized bed using the Eulerian-Lagrangian method.In this model,the gas phase was described by the large-eddy simulation(LES)and the solid phases was simulated by the Multi-Phase Particle-In-Cell(MP-PIC)method.Stable gas-solid circulation in the DCFB has been achieved.On the base of experimental verification,the effects of various operating conditions on flow structure and particle distribution were numerically studied and obtained some valuable discoveries which are difficult to ascertain by experiments.