MODELING OF HEAT TRANSPORT IN A DIRECT METHANOL FUEL CELL WITH ANISOTROPIC GAS DIFFUSION LAYERS

摘要

A non-isothermal two-dimensional two-phase numerical model is developed in this paper to investigate the heat generation and transport processes in a direct methanol fuel cell with anisotropic gas diffusion layers (GDLs). Thermal contact resistances at the GDL/CL (catalyst layer) and GDL/Rib interfaces, and the deformation of GDLs are considered together with the inherent anisotropy of the GDL. Latent heat effects due to condensation/evaporation of water and methanol between liquid and gas phases are also taken into account. Formulation of the two-phase mass transport across the membrane electrode assembly (MEA) is mainly based on the classical multiphase flow theory in the porous media. The numerical results show that the overall heat flux in MEA is mainly contributed to heat generation in anode and cathode CLs. And the three anisotropic factors of the GDLs, including the inherent anisotropy, the spatially varying contact resistances, and the deformation of GDLs, have a strong impact on the heat transport processes in the DMFC by altering the distribution of temperature across the MEA.