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 in uence of the  ow direction and distribution on the rate of reactants diffusion, three novel models of vertical reactant  ow injection into the anode and cathode reaction area  eld have been introduced. They consist of one inlet, two inlets, and a continuous channel. The governing equations on the steady three dimensional non-isothermal  ow have been discretized using the  nite volume method. These 3D simulations evaluate the effectiveness of  ow direction on the transportation and chemical phenomenainside the PEM fuel cell by applying the computational  uid dynamics (CFD) method to the transportation and conservation equations with the suppositions of steady state and one phase  ow. 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 bene ts, such as extra diffusion of reactants, because of  ow direction, improvement of species distributions, enhancement in temperature management and more effective water removal due to the number of outlets and uniformcurrent distribution. Furthermore, the continuous channel inlet presents a substantially higher performance than the others due to covering more reaction area and having a high rate of reactants diffusion. With regard to the polarization curve along with other advantages, the mentioned design can be strongly recommended to obtain high operating ef ciency and can be considered for the manufacture of a new generation of PEM fuel cells in the form of high performance stacks.

کلیدواژه ها:

PEM fuel cell ، Vertical injection ، Numerical modeling ، Polarization ، MEA ،