Two-Phase Flow in the Gas Diffusion Layer with Different Perforation of Proton Exchange Membrane Fuel Cell

Proton exchange membrane fuel cell (PEMFC) has drawn the world’s attention for its advanced features of zero-emission, high-power density and low noise. However, water management significantly influences the performance of proton exchange membrane fuel cells (PEMFC). Gas diffusion layer (GDL) is an important pathway for water transport in the PEMFC. The presence of excessive liquid water in the cathode GDL will cause “water flooding” and block the reactant transport to catalyst sites. Therefore, it is critical to improve water management in the GDL to enhance cell performance. Specially, perforated GDL is an effective way to improve the water transport process. In this study, the volume of fluid (VOF) method is used to numerically simulate the transport process of liquid water in perforated GDL with different hydrophilicity distributions. The GDL geometry is reconstructed based on the stochastic parameter method. With our numerical method, the GDLs with cylindrical and conical perforations are compared to understand the water transport process. Additionally, the effects of perforation shapes and fiber hydrophilicity gradient distributions on the water transfer process also been discussed. The results show that the GDL with conical perforation (bottom surface close to the inlet), liquid water tends to diffuse along the though-plane direction. The GDL with cylinder perforation are most effective to transporting fluid water. The water saturation in GDLs with gradient wettability is higher than that in GDLs without gradient wettability.