Water and thermal management in a PEM fuel cell--A parametric study

Non-uniform consumptions of oxygen and hydrogen in PEM fuel cells cause non-uniform current distribution and reduce the output power. In this study, a two dimensional model is proposed based on conservation laws and electrochemical equations to provide useful insights into water and heat transport mechanisms and their effects on the cell performance. The presence of liquid water in the GDL decreases the active catalyst surface which in turn degrades cell performance. The model is based on these assumptions: steady-state and isothermal cell conditions, ideal gas mixtures, isotropic diffusion media and negligible potential drop due to anode activation. The results show that inlet stoichiometry and relative humidity, inlet pressure and cell temperature are important factors that affect cell performance and the state of two phase conditions in the cathode side.

Keywords:

PEM fuel cell , current distribution , cathode flooding , modeling , two-phase flow