摘要
建立了一个三维的弯管式中空纤维膜渗透汽化传质CFD模型,研究Dean涡对渗透汽化过程传质的影响,描述了膜内侧的浓度和速率变化情况,该模型与Leveque传质关联式具有良好的一致性。研究结果显示:弯管膜中Dean涡的存在能降低边界层传质阻力,总传质系数比直管膜提高了4倍;在不同的入口速率和浓度条件下,弯管膜内侧的壁面剪应力均大于直管膜。在膜阻力远小于边界层阻力的情况下,入口速率0.275 m·s^(-1),水浓度10%(质量)时,弯管膜的渗透通量为12636 g·m^(-2)·h^(-1),是直管膜的5倍。可见,弯管式中空纤维膜在渗透汽化过程中具有显著的强化传质效果。
A three-dimensional CFD model of perforated vaporization mass transfer of hollow fiber membrane was established.The effect of Dean vortex on mass transfer in pervaporation process was studied.Concentration profiles and velocity distribution inside the membrane were determined and the mass transfer coefficient simulated by this model was validated by Leveque equation.The results showed that the mass transfer resistance of bounder layer in the curved membrane was influenced by Dean vortex,and the total mass transfer coefficient was improved 4 times over the straight membrane.The wall shear stress inside the curved membrane is larger than the straight membrane at different inlet velocity and concentration.When membrane resistance was much less than boundary layer resistance,inlet velocity was 0.275 m·s?1 and water concentration was 10%(mass),permeation flux in the curved membrane was 12636 g·m?2·h?1,which is 4 times higher than the one in straight membrane.It proved that the predicted data are consistent with Leveque equation,and the curved membrane has significant effect of mass transfer enhancement in pervaporation process.
作者
王洋
庄黎伟
马晓华
许振良
王志
WANG Yang;ZHUANG Liwei;MA Xiaohua;XU Zhenliang;WANG Zhi(State Key Laboratory of Chemical Engineering,Membrane Science and Engineering R&D Laboratory,Chemical Engineering Research Center,East China University of Science and Technology,Shanghai 200237,China;State Key Laboratory of Chemical Engineering,School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2018年第11期4655-4662,共8页
CIESC Journal
基金
国家自然科学基金项目(21706066,2015BAB09B01)
中国工程院咨询项目(2017-XZ-08-04-02)。