针对电容法/膜电容法(CDI/MCDI)2种海水淡化过程，耦合求解质量、动量、电荷守恒方程多孔达西渗流，并结合吸附动力学方程，建立CDI和MCDI法海水淡化过程的三维瞬态多物理场耦合分析模型。在验证所建分析模型可靠性基础后，开展CDI和MCDI单元内完整“吸附-脱附”过程的模拟，分析CDI和MCDI脱盐过程中内部多物理场耦合作用机制，揭示CDI与MCDI两种海水淡化过程的规律及差异。最终结果表明：离子交换膜的存在，使得MCDI单元内流速及浓度分布规律与CDI单元存在一定差异；离子交换膜可有效防止共离子排斥效应并抑制“二次吸附”，使得MCDI单元的吸附及脱附效率优于CDI单元。
To investigate desalination processes of capacitive deionization/membrane capacitive deionization (CDI/MCDI), three-dimensional multi-physical models of CDI and MCDI were established by combing the mass, momentum, porous Darcy flow, charge conservation equation and adsorption kinetic equation. After the reliability of the model was checked, the adsorption and desorption processes of CDI and MCDI were simulated and the coupling mechanisms of multiple physical fields in desalination processes were analyzed. Differences between CDI and MCDI were revealed. The final results indicate that distribution of velocity and concentration is altered in desalination processes of MCDI and CDI due to the effects of ion exchange membrane. It can also help to prevent co-ion repulsion and inhibit secondary adsorption, which contributes to the adsorption and desorption efficiency of MCDI unit being better than that of the CDI unit.
2022,44(23): 54-59 收稿日期：2022-03-28
DOI：10.3404/j.issn.1672-7649.2022.23.011
分类号：U664.591
基金项目：国家自然科学基金资助项目（51906091），江苏省高等学校自然科学基金（19KJB470019）
作者简介：刘锐(1988-)，男，博士，讲师，研究方向为电容去离子脱盐
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