Investigation of Water Vapor Diffusivity through Gdl of a Pemfc

Water transport through the gas diffusion layer (GDL) of a proton exchange membrane (PEM) fuel cell is of critical importance in the operation of the fuel cell. In this study, the transport of water vapor through the GDL is investigated. A one-dimensional, single-phase heat and mass transfer model is developed to investigate the diffusivity of water vapor through the GDL of a PEMFC. An experimental apparatus is developed to induce water vapor gradients across the GDL while varying humidity levels and flow rates comparable to actual fuel cell operational conditions. Experimental data is then used to extract an effective water vapor diffusivity from the numerical model. Effective diffusivity was found to be 0.104x10 m/s and the overall mass transfer coefficient was found to be 0.019 m/s at a temperature of 40°C.