Effects of GDL Porosity and Membrane Thickness on Vapor Feed Direct Methanol Fuel Cell Performance

A three-dimensional CFD model is developed to study a vapor feed direct methanol fuel cell. Governing equations include conservation of mass, momentum, energy and species as well as electrochemical reactions. Flow is assumed to be laminar, steady and fully developed at channel exit and the walls are adiabatic. A CFD code is developed based on the finite volume method to solve the governing equations. The power law and central difference schemes are used for the discretization of the convective and diffusive terms, respectively. A smooth and orthogonal grid with proper stretch is implemented. Effects of the GDL porosity and membrane thickness on polarization curve and power density are investigated. Simulation results illustrate that an increase of GDL porosity yields an increase in cell current density and power density. Moreover, an increase of membrane thickness slightly decreases cell current density and power density

کلیدواژه ها:

DMFC ، CFD simulation ، GDL porosity ، membrane thickness ، polarization curve