中空纤维膜脱氧过程中Dean涡强化传质研究（英文）

Mass transfer enhancement of hollow fiber membrane deoxygenation by Dean vortices

目的:在螺旋中空纤维膜脱氧过程中引入了Dean涡,与线型中空纤维膜脱氧过程相比传质速率显著提升。本文旨在建立新的螺旋中空纤维膜脱氧过程传质模型,探讨管程流体雷诺数、中空纤维膜结构参数、壳程真空度和操作温度对Dean涡强化传质效果的影响,并优化螺旋中空纤维膜脱氧过程操作参数。创新点:1.建立新的螺旋中空纤维膜脱氧过程传质模型;2.该传质模型可以应用于任何螺旋中空纤维膜气-液过程的传质行为描述。方法:1.实验研究管程流体雷诺数、中空纤维膜结构参数、壳程真空度和操作温度对Dean涡强化传质效果的影响,并与线型中空纤维膜传质进行对比。2.利用螺旋坐标系下的质量连续性方程以及Dean涡的摄动解描述管程溶质的传质行为;利用改进的尘气模型描述膜孔道内多组份气体的扩散行为;耦合建立新的螺旋中空纤维膜脱氧过程传质模型,并与实验结果进行比较。3.模拟脱氧过程的氧、氮、水三种组分的浓度分布,优化螺旋中空纤维膜脱氧过程的膜结构参数和操作参数。结论:1.实验和模拟结果均证实Dean涡可以有效提升脱氧传质速率,最大传质增强因子为2.2。2. Dean涡主要受到管程雷诺数和中空纤维膜曲率的影响;当管程雷诺数较大时,中空纤维膜即使存在很小的曲率,传质的速率也有显著的提升。

This paper reports a modeling and experimental study of the mass transfer enhancement of water deoxygenation by using a helical hollow fiber membrane(HHFM)to enable Dean vortices.Experiments demonstrated that the HHFM deoxygenating rate was doubled compared with straight hollow fiber deoxygenation.A new model to describe the HHFM deoxygenation mass transfer was derived combining the helical coordinate system mass continuity equation on the lumen side and a modified dusty gas model for the mutual gaseous diffusion in the porous membrane.The model simulation showed that Dean vortices induce transverse fluid disturbance in the fiber,which significantly promotes lumen side mass transfer.The key parameters influencing the strength of Dean vortices are the Reynolds number of the lumen side and the curvature of HHFM.Operating and membrane structure parameters were optimized for HHFM deoxygenation design.The new model could be employed to describe quantitatively the mass transfer behavior of all types of HHFM gas-phase separation processes.