Transport phenomena in the porous cathode of a proton exchange membrane fuel cell

Simultaneous heat and mass transfer in the porous cathode of a proton exchange membrane (PEM) fuel cell is generated by the exothermic chemical reaction at the catalyst layer. A two-dimensional steady state model in a cross section of the porous electrode taken normal to the gas flow in the channels is presented We consider a multicomponent inlet feed composed of oxygen, nitrogen, and water vapor on the cathode side. The mathematical formulation reduces to a system of four nonlinear second-order elliptic partial differential equations subject to appropriate nonlinear boundary conditions. Numerical solutions are obtained rising a finite-difference method. Results are presented for various operating conditions and design parameters in order to identify the important factors in the performance of the fuel cell. From the calculated values of the vapour pressure and temperature, the regions of vapor oversaturation are identified.