摘要
采用计算流体力学(CFD)的方法,对自制的矩形平板PDMS(聚二甲基硅氧烷)复合膜构造而成的板框式渗透汽化膜组件进行了流体流动和对流传质的研究,并以乙醇水溶液为分离对象,通过实验对模拟结果加以验证。数值模拟结果给出了原料液在流道内的速度分布以及乙醇质量分数云图,揭示了速度分布对渗透通量的影响。对不同流量下的模拟计算结果对比分析可知,增大流量有利于缓解浓差极化现象,降低传质阻力,从而促进渗透传质进行。基于串联阻力模型,探讨了膜表面的液体流动状况对膜传质的影响,拟合出对流传质系数与Reynolds数的关系式,与实验值极为吻合。
Fluid flow and convective mass transfer in a rectangular plat-and-frame module filled with a composite PDMS(polydimethylsiloxane) membrane for pervaporation separation of aqueous ethanol was studied by using experiment and computational fluid dynamics(CFD). Velocity distribution and mass fraction profile of ethanol in flow channel were provided from the result of numerical simulation, in which the influence of velocity distribution on permeation flux was also revealed. With the comparison of the simulation results at different flow rates, it can be found that with the increase of flow the concentration polarization will be alleviated and the resistance to mass transfer will be lowered, thereby the permeation process promoted. Based upon resistance-in-serials model, the effects of the membrane surface flow condition on mass transfer were explored. Moreover, the simulated expression of convective mass transfer coefficients and Reynolds number was obtained, which is in good agreement with the experimental results.
出处
《化工设备与管道》
CAS
2016年第5期20-25,共6页
Process Equipment & Piping
基金
国家自然科学基金资助项目(20776088)
关键词
渗透汽化
PDMS复合膜组件
流动
对流传质
计算流体力学
乙醇水溶液
pervaporation
composite PDMS membrane module
flow
convective mass transfer
computational fluid dynamics
aqueous ethanol
