气态悬浮焙烧炉一级旋风预热器的数值模拟

Numerical Simulation on Primary Cyclone Preheater of Gas Suspension Calciner

利用FLUENT软件对气态悬浮焙烧炉一级旋风预热器内气-固两相流动状态进行数值模拟。针对一级旋风预热器结构的非对称性和流场的三维强旋流特性,利用六面体结构化网格离散求解区域,选用雷诺应力湍流模型模拟气相流动,采用颗粒随机轨道模型模拟颗粒相流动,选用单向耦合方式处理气-固两相的耦合。对一级旋风预热器的气相流动进行三维数值模拟,结果表明:静压沿径向由外向内逐渐降低,且在中心轴线附近最低,沿轴向自上向下降低较小;在一级旋风预热器壁面和旋转轴心位置,切向速度等于零,呈现典型的兰金组合涡分布,在气流入口位置,切向速度的加速并不明显,进入下部柱体段后,切向速度有所降低。研究结果可为一级旋风预热器的生产运行和优化设计提供参考。

This paper presents the numerical simulations on gas-solid phases flow in the primary cyclone pre-heater of gas suspension calciner by software FLUENT.Given asymmetrical structure and its 3-D strong swirling flow field of the primary cyclone pre-heater,structural hexahedron grids were adopted to discrete computational domain,Reynolds Stress Model and Stochastic Trajectory Model were employed to simulate the gas-phase flow and solid-phase flow respectively,and one-way coupled manner was used to deal with the coupling of gas-solid phases flow.3-D numerical simulation results of the gas-phase flow in the primary cyclone pre-heater reveal that static pressure reduces in the radial direction and reaches the lowest value near the central axis,and also reduces from the top to the bottom along the axis.The tangential velocity is equal to zero both on the wall of the primary cyclone pre-heater and near the rotation axis.The research result also shows that the typical Rankine′s vortex distribution of the tangential velocity whose acceleration is unnoticeable near the entrance.The tangential velocity reaches the maximum value after shrinkage of the volute and reduces after entering the lower cylinder.Those conclusions can be of great help in the production operation of primary cyclone pre-heater and its optimum design.