연료전지 금속 분리판 유로 형상 인자에 따른 가스 확산층 변형 및 협의 유로내 유동 특성 분석

Abstract

This study is aimed to figure out the behavior of gas diffusion layer(GDL) intrusion into channels on metallic bipolar plates. First, the GDL intrusion calculation is performed with computational structural analysis. The static analysis of intrusion behavior was conducted with five cross-sectional parameters: channel to rib width ratio, draft angle, inner fillet radius, channel depth and clamping pressure. Using the information of structural deformation, computational fluid dynamics analysis is then followed to comprehend flow characteristics in the deformed channels. Numerical results are verified against experimental data in the literature. It is found that draft angle and channel ratio are the major factors of GDL compression and the GDL intrusion reduces the cross-sectional area down to 45% in the most intruded channel, leading additional pressure drop of 0.12 bar. The GDL compression induces significant degradation of PEMFC performance and the combined structural and CFD analysis can be greatly utilized to design an optimized channel dimension.