The effect of vertical injection of reactants to the membrane electrode assembly on the performance of a PEM fuel cell

In order to present a new and high performance structure of PEM fuel cell and study the influence of the flow direction and distribution on the rate of reactants diffusion, three novel models of vertical reactant flow injection into the anode and cathode reaction area field have been introduced. They consist of one inlet and two inlets and also a continuous channel. The governing equations on the steady, three dimensional non-isothermal flow have been discretized using finite volume method. These 3D simulations are going to evaluate the effectiveness of flow direction on the transportation and chemical phenomena inside the PEM fuel cell by applying computational fluid dynamics (CFD) method to the transportation and conservation equations with the suppositions of steady state and one phase flow. The numerical results are validated with experimental ones for available common fuel cells. The results show that the presented geometries have several mechanical and chemical benefits such as extra diffusion of reactants because of flow direction, improvement of species distributions, enhancement in temperature management and more effective water removal due to the number of outlets and uniform current distribution. Furthermore, the continuous channel inlet due to cover more reaction area and high rate of reactants diffusion presents substantial higher performance than others. With regard to the polarization curve along with other advantages, the so-called design can be strongly recommended for obtaining high operating efficiency and can be considered for the manufacturing of new generation of PEM fuel cells in the form of high performance stacks.