Numerical modeling of species transport and functional characteristics of a proton exchange membrane fuel cell using an agglomerate model with a multi-phase model

Abstract

In this study, the species transport and functional characteristics of a Proton Exchange Membrane Fuel Cell (PEMFC) using the agglomerate model are carried out. The modeling is two-dimensional and a two-phase flow is provided to separate liquid water and gas inside the fuel cell. The water transfer modeling is carried out using three mechanisms of vapor, liquid water, and dissolved water through the membrane. The entropy generations due to viscous loss, heat transfer, Ohmic losses, mass transfer, and latent heat are obtained. The effects of agglomerate radius, active layer thickness, permeability, and porosity on the current density, species transport, power density, liquid water, temperature distribution, and entropy generation are investigated. The results show that permeability has a significant effect on water management formed in the cathode gas diffusion layer. Also, the total entropy generation is more evident at the low voltages. The findings show that using a smaller agglomerate radius and larger active layer thickness has a better effect on the current density and thus results in higher power density. At 0.7 V, as the agglomerate radius doubles, the current decreases by 41 %. At 0.6 V, however, a 34 % increase in power density is seen in the minimum agglomerate radius.