中空纤维膜组件壳程流动的数值模拟

Numerical simulation of shell-side flow in hollow fiber membrane modules

利用随机顺序添加算法(RSA)建立了中空纤维膜组件壳程三维几何模型,研究了膜组件壳程复杂结构条件下的流体力学特征,进行了组件壳程流动的数值模拟。通过与实验数据及现有经验关联式的比较表明,在低Reynolds数下,基于上述几何模型的数值模拟可较好地预测膜组件的传质特性,能够替代经验关联式,为具有特定几何结构的膜组件和膜过程设计提供依据。模拟结果表明,膜丝轴向的非平行分布导致的径向流动能够消除局部沟流和死区带来的影响,合理地安排膜丝沿组件轴向的排布方式是提高组件分离性能的潜在手段之一。

Random sequential addition（RSA）algorithm was utilized to develop geometric models for hollow fiber membrane modules.The models,featuring radial and axial structure complexity in modules＇ shell-side,were further integrated into numerical simulations to study hydrodynamic behaviors within tricky physical boundaries.Comparisons among simulation results and experimental data,as well as the empirical correlation in literature showed that the simulations were capable of describing the performance of certain commercial modules at low Reynolds number,thus making it possible to replace correlations for performance predictions in membrane module design.On the other hand,radial flow induced by axial non-ideal distribution of fibers might offset channeling and dead zone effects,which were key factors deteriorating module performance.A good design of axial fiber alignment might serve as a potential method for module performance intensification.