Heat transfer in PEM cooling flow field with high porosity metal foam insert

Abstract

Conventional cooling channel flow fields of Polymer Electrolyte Membrane Fuel Cells (PEMFCs) introduce some challenges that would reduce the cell total performance. So presenting novel ideas to improve the cooling flow fields is fully appreciable. The more common conventional flow fields include the serpentine, parallel and multichannel would be precisely studied in this paper. In order to see the effect of porous materials in heat transfer, metal foams were introduced to the channels. Unlike continuous long flow passages in conventional channels, metal foams provide randomly interrupted flow passages. Re-circulation of fluid, due to randomly distributed tortuous ligaments, enhances the heat transfer in these new channels. Moreover, to assess the features of utilizing metal foams in cooling channels, different parameters like metal type, porosity percentage and also the cooling media were investigated. Since both thermal and hydraulic points of view are important in cooling engineering, the heat transfer and pressure drop for all three channel types were verified. The results showed that enhancing the porosity of the metal foam would decrease both heat transfer and pressure drop. Also the multi-channel type revealed the best heat transfer behavior in presence of metal foams.