Effect of stack orientation on the performance of H2/Air PEM fuel cell

An Experimental study has been carried out to investigate the effect of stack orientation at different cathode air flow rate on the performance of H₂/Air PEM fuel cell. A 25 cm² single cell with serpentine anode and straight cathode flow channels is used. An orientation mechanism has been designed to facilitate the orientation position of the fuel cell stack. Performance of the fuel cell is characterized through analysis of the polarization and the power density vs. current density curves as well as the hydrogen utilization and the cell electric efficiency. The hydrogen flow rate, cathode air temperature and relative humidity are kept constant at 60 ml/min, 20 °C and 80 %, respectively, while the cathode air flow rate values are 220, 440 and 660 sml/min in addition to the free breathing case. Obtained results show that, cell orientation has a significant effect on the performance of the fuel cell. It can be concluded that optimum cell orientation values are 30° for cathode air flow rate 220 sml/min and 90° for free breathing, 440 sml/min and 660 sml/min cases.