Metal foam as a turbulent flow distributor in the cooling channels of a PEM fuel cell - A numerical study

Abstract

Operating temperature is one of the most important parameters affecting the performance of polymer electrolyte membrane (PEM) fuel cells. The cooling system of a PEM fuel cell maintains the temperature of the fuel cell stack at a specific value and removes the heat generated in the cell. This paper presents 3D numerical simulation of a water-cooled PEM fuel cell cooling system, with a metal foam insert instead of traditional cooling channels. We explore the possibility of using metal foams for thermal management of fuel cells. We consider the turbulent flow of the coolant through the porous medium and investigate the effect of metal foam properties, including porosity and pore size, on the performance of the cooling system. The Brinkman-Darcy-Forchheimer equation is employed to analyze the flow field in the porous medium and the k - ϵ model is utilized for turbulence studies. The numerical results indicate that, at a specific Reynolds number, by increasing the porosity and the pore size of the metal foam, the pressure drop decreases, while the maximum temperature difference occurs in the cooling plate. The temperature uniformity index also increases. The latter result indicates that the temperature distribution in the cooling plate becomes more uniform. The obtained results of present study are in good agreement with available experimental and analytical data, confirming that the presented computational fluid dynamics modeling using the selected turbulence model can accurately predict the flow field parameters in the cooling channels of PEM fuel cells. © 2019 IOP Publishing Ltd.