计算流体力学在膜过程传质优化中的研究进展

Progress on CFD simulation for mass transfer optimization of membrane process

分别从膜组件、膜本身结构、膜过程操作条件、膜过程耦合4个方面的优化阐述了近期计算流体力学(CFD)在膜过程传质优化中的研究及应用进展。指出CFD模拟对料液隔网的形态研究和局限性改进显示出了优越性;在膜表面形貌及支撑层结构修饰与优化方面发挥了关键作用;对脉动流、两相流与机械振动的引入及其在流场、浓度场、温度场中的可视化研究也已相对成熟;此外,CFD模拟证明,将膜过程与其他动态分离过程相耦合也是提高膜表面剪切速率、增强传质与分离效率的有效途径。指出了目前大部分CFD模拟工作的准确性还不够、通过模型优化改善准确性时会不可避免地增加模拟计算的复杂性以及膜组件的设计研究与材料加工工艺还不很匹配等存在的问题,认为该领域未来的发展方向将集中在不同优化方式的耦合,以及利用新兴的检测技术与制备工艺弥补目前实验数据缺乏的弊端,得到更贴合实际的理论模型。

Recent research progress on how CFD helps contribute to mass transfer in membrane process respectively from four different aspects, membrane module, membrane structure, operation conditions and process coupling were reviewed in this paper. It pointed out that the superiority of CFD simulation for mass transfer optimization of membrane process is widely proved not only in the design and modification of feed spacer and membrane structure, but also in the visualization researches of pulsating flow, two-phase flow and mechanical vibration in different fields （flow, concentration and temperature） . In addition, CFD simulation was employed to illustrate mass transfer mechanism of coupling membrane with other dynamic systems and found it a promising way to increase the shear rate of boundary layer, which can further result in better separation efficiency. However, it is still difficult for CFD simulation to get both high accuracy and low computation expense. On the other hand, current material processing technology cannot satisfy the simulation study, which hindered the practical application of CFD. Future researches will focus on combining various optimization methods and applying emerging detection and manufacturing technologies to make up the deficiency in experiment and thus, achieve new computational models which fit the practical situation better.