CDI法海水淡化单元吸脱附过程的多物理场模拟及特性分析

Multi-physics Simulation and Characteristics Analysis of Adsorption and Desorption Processes in CDI Desalination Units

针对电容去离子(CDI)海水淡化单元,建立单元内吸、脱附过程的多物理场耦合模型。通过模拟分析吸附及2种脱附方式(电压断开和电压反接)下,操作参数(工作电压、入口流速)和几何参数(电极厚度、流道间距)对CDI单元吸附脱盐及脱附再生过程的影响规律。结果表明,吸附效率随入口流速及流道间距的增大而减小,随多孔电极厚度及极板电压的增大而增大;吸附过程中,最小出口浓度随入口速度和流道间距的增大而增大,随工作电压增加而减小,与电极厚度无关;与脱附方式为电压断开相比,脱附方式为电压反接时,脱附完成所需时间较小。

For capacitive deionization(CDI)unit,the paper establishes a multi-physics field coupling analysis model for the process of adsorption and desorption in the unit.The effects and the law of influence of different operating conditions(voltage and inlet velocity)and geometrical parameters(channel spacing and plate thickness)on the process of adsorption desalination and desorption regeneration(two desorption modes:disconnection of voltage and reverse connection of voltage)are analyzed by the numerical simulation method.The results show that the adsorption efficiency decreases with the increase of inlet velocity and channel spacing,and increases with the increase of working voltage and electrode thickness.For the adsorption process,the minimum outlet concentration increases with the increase of inlet velocity and channel spacing,and decreases with the increase of voltage,and is independent on the electrode thickness.Compared with the desorption mode of disconnection of voltage,the completion of desorption with the reverse connection of voltage takes less time.