Effect of operating conditions on the performance of a PEM fuel cell

In this study, a two-phase flow model based on species transport, energy, and electrochemical equations was developed for polymer electrolyte membrane fuel cell (PEMFC). The influences of heat sources and sinks, and water transport inside the fuel cell were also taken into account. In this regard, the effect of the operating conditions including cell temperature and pressure, anode and cathode inlet humidity, and anode and cathode stoichiometric ratios on the fuel cell performance was investigated. The simulation results show that inlet humidity and stoichiometric ratio of the anode side, cell pressure and temperature, and distribution of the heat sources and sinks are crucial factors affecting the cell performance and the two-phase flow characteristics. The amount of heat produced (or consumed) as a result of heat sources (or sinks) considerably decreases at the channel inlet, whereas it decreases slowly in the rest of the flow channel. It was found that, for moderate to high current densities, the fuel cell performance diminishes with an increase of the cell pressure. Increasing inlet humidity and stoichiometric ratio of the cathode side insignificantly influences the polarization curve; however, the cell performance enhances with an increase of the cell temperature. (C) 2019 Elsevier Ltd. All rights reserved.