Analysis on Influence of Micropore Spacing and Size on Droplet Flow Transport Characteristics on Gas Diffusion Layer in PEMFC

Proton exchange membrane fuel cell（PEMFC）is considered as one of the most promising power devices for new energy vehicles，whose performance is affected by the droplet formation and dynamic transport properties on the surface of the gas diffusion layer（GDL）. In this paper，based on the pseudo-potential model of the lattice-Boltzmann method（LBM），the dynamic processes of droplet emergence，growth，and shedding from the GDL surface are simulated，and the effect of micro pore spacing and micro pore size on the dynamic characteristics of droplets on the surface of the GDL as well as the pressure drop in the flow channel are analyzed in detail. The research results show that in the case of dual inlet holes，when the distance between two micropores is less than a certain value，the two droplets will merge. The merged droplet will increase the pressure drop in the airflow channel and shorten the time for droplet discharge. When the two micropore spacing is sufficiently large，there is almost no interaction between the two droplets，with the same droplet exclusion time，and the pressure drop inside the flow channel decreases with the increase of the micropore spacing. And the pressure drop in the flow channel decreases with the increase of micropore spacing. The motion of droplets with different micropore sizes on the surface of GDL is mainly affected by the gas-actuated shear force，and the motion period of droplets with upstream micropore size larger than downstream micropore size is shorter compared to the motion period of droplets with larger downstream micropore size. © 2024 SAE-China. All rights reserved.