Optimization membrane module structure of column type by CFD

doi:10.11949/j.issn.0438-1157.20170243

Abstract

Abstract:

Gas-liquid two-phase fluid in membrane module of different column type was simulated by Euler model and porous medium model. The effect of the length of membrane module and the number of aerator holes (opening rate=1.92%) on gas-liquid distribution, wall shear stress, turbulent viscosity and velocity of liquid was investigated by CFD simulation. The simulation results showed good agreement with the experimental data. The results demonstrated that uniform distribution of gas-liquid and water velocity, the intensity of wall shear stress and turbulent viscosity was efficiently improved by decreasing the diameter of aerator holes and increasing the number of aerator holes; increasing the length of membrane module was significantly benefit to improve the capacity of a single membrane module, and make full use of gas scrub the wall of membrane. Considering installation, transportation, distribution of membrane flux and energy consumption, the membrane module with the diameter 250 mm that the diameter and the number of aerator holes respectively is 6.32 mm and 30, and the length of membrane module is 2-2.5 m exhibited a best performance.

Key words: membrane module of column type, computational fluid dynamics, Euler model, porous media model

摘要：

采用Euler模型与多孔介质模型对不同结构的柱式膜组件内的流体流动进行了计算模拟。研究了曝气孔数目（开孔率为1.92%保持不变）与膜组件高度对膜组件膜丝填充区域内的气液两相分布、壁面剪应力、湍流黏度以及液相速度场的影响。计算模拟数据与实验结果吻合良好。计算模拟表明：通过减小曝气孔直径，增加曝气孔数目的方式能够促进气液两相流场与液相速度场的均匀分布，以及壁面剪应力与湍流黏度的增强；增加膜组件的高度，有利于增加单支膜组件膜面积的同时充分利用曝气擦洗过程中气液两相流对膜丝壁面进行高效的气擦洗。综合考虑膜组件的安装运输、膜丝通量分布以及能耗等因素，对于直径250 mm的膜组件采用曝气孔的直径为6.32 mm，数目为30个，长度在2~2.5 m之间为最优。

关键词: 柱式膜组件, 计算流体力学, Euler方法, 多孔介质模型

CLC Number:

TQ028.8

XIONG Changchuan, LI Weixing, LIU Yefei, XING Weihong. Optimization membrane module structure of column type by CFD[J]. CIESC Journal, 2017, 68(11): 4341-4350.

熊长川, 李卫星, 刘业飞, 邢卫红. 柱式膜组件结构的CFD优化设计[J]. 化工学报, 2017, 68(11): 4341-4350.

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