A two dimensional partial flooding model for PEMFC

Proton exchange membrane fuel cells (PEMFCs) have attracted much attention in these years. In PEMFCs, liquid/gas two-phase flow is a common phenomenon, which has great influence on fuel cell performance. However, the liquid water transport process has not been satisfactorily modeled yet. In this work, a two dimensional partial flooding model was developed, in which the pore size distribution of the gas diffusion layer (GDL) is taken into consideration in the explanation of fuel cell flooding for the first time. Liquid water produced is considered to flood a fraction of the GDL hydrophobic pores with diameter greater than the capillary condensation threshold diameter, and the unflooded pores will serve as passageway for gas transportation and the corresponding catalyst area is available for electrochemical reaction. Use this model, it is simple to explain membrane dehydration and electrode flooding. Different operation conditions have been studied with the model and the model polarization curves show reasonable accordance with the experimental results.