固定床流体流动特征数值模拟

Numerical simulation for character of fluid flow through packed bed

为了研究固定床边壁效应、固定床床层数的变化以及颗粒的填充倾斜角度等参数对床内流体流动状况的影响,基于Ergun方程建立了轴对称多孔介质数学模型。同时对床内流体流动状况进行了研究:在床高确定的情况下,随着床层数的增加,压强降减少;随着颗粒填充倾斜角度的增加,压强降也减少,速度径向分布不均;在固定床边壁附近,气体速度明显增大。计算结果与实验值的比较表明模型能有效地描述固定床压强降和床内流体流动状况。

To study the effects of the tube wall, the number of layers and inclination angle on flow patterns, the mathematical model based on Ergun＇s equation was built to simulate fluid flow through packed bed. The favorable comparison of the measured data with the computed results indicates that the mathematical model is effective to describe the fluid flow through packed bed. The calculated results show that the pressure drop decreases with the number of layers increasing under the constant height of packed bed. The pressure drop decreases with the increase of layer inclination angle, but the radial distribution of gas velocity is non-uniform with the increase of layer inclination angle. The effect of tube wall has an influence on distribution of gas velocity. The gas velocity increases adjacent to the tube wall.