Multiscale Simulation on Heat and Mass Transfer in Porous Electrodes for Electrolytic Air Dehumidification

As a new type of electrochemical method, air dehumidification based on PEM electrolyte membrane has the advantages of compact structure, no noise, and no polluting products. It has broad application prospects in the storage of products that require high humidity accuracy, and even in deep-sea exploration, aerospace, and other fields. In this paper, the transport and electrochemical reaction in porous electrodes was simulated. The dehumidification process of the catalyst layer with micro-structures and the macro-components were respectively simulated by lattice Boltzmann method (LBM) and one-dimensional finite volume method (FVM). Based on the Nernst equation and the Butler-Volmer equation, the instantaneous reaction rates at different interfaces were calculated which controlled by the concentration of water vapor and impedance. The predicted dehumidification rate closely matched the experimental results with an average error of relative humidity of 0.53%. It visualizes transfer and dehumidification reactions inside components during operation, and has capabilities such as evaluating component performance and tracking performance obstacles in the catalytic layer (CL).