fuel cell, seven layers, water transport, one-dimensional, steady-state, modeling
This model is an isothermal, isobar, one-dimensional and steady-state model for a polymer electrolyte fuel cell with a 117 Nafion membrane that considers seven-layer of fuel cell. In former years, Springer and colleagues presented the model for five-layer, In which the anode and cathode catalyst layer regardless available. On the other hand, Chen and Chang presented another the five-layer model that were ignoring the input anode and cathode channel, while this model has studied seven layers of fuel cell. Model results show that when the cell works with low current density and 100 % saturation, back diffusion will be significient. Also if the cell to work in high current density, electroosmotic drag will be significient. So water is reduced by the anode on the border. With increasing current density, concentration of water in the cathode electrode is increased and water vapor may be a serius problem for the hole blocking gas diffusion layer and catalyst layer and reduce the amount of oxygen transport. Therefore, if the relative humidity reduction to about 80%, membrane can be kept in the suitable moisture and control the flooding of water. From other modeling results, using thinner membrane and high porosity of gas diffusion layer, the water towards the surface membrane and the anode increases. This prevents the land of anode and makes controllable flooding of cathode electrode. It should be mentioned that the thinner membrane has less resistance and the high voltage so increases the cell performance. On the other hand, in a specified current density, the lowest membrane resistance in most Stoichiometry coefficient of hydrogen is created along the cell voltage is more.