Optimization of channel geometry in a proton exchange membrane (PEM) fuel cell

Bipolar plates are the important components of the PEM fuel cell. The flow distribution inside the bipolar plate should be uniform. Non-uniform flow distribution inside the bipolar leads to poor performance of the fuel cell and wastage of expensive catalyst. A single channel PEM fuel cell is taken and electrochemical analysis is carried out on it. The results are compared with the available published experimental data obtained by other research group, and they are found to be in good agreement. A baseline design of the bipolar plate is taken and numerical analysis is carried out. The results show that the flow distribution is non-uniform. The baseline design is changed to an improved design to obtain a uniform flow. The improved design yielded a uniform flow. A single channel is taken from the improved design of the bipolar plate and electrochemical analysis is carried out on it. The geometry of the fuel cell channel is changed from rectangular to square, semi-circle and triangular shapes and the performances of the fuel cell are observed. The performance of the rectangular channel is found out to be the best, and the performance of the triangular channel is poor compared to rectangular channel design. The operating temperature of the fuel cell is varied and the results show that increasing the fuel cell temperature from 323K to 353K increases the fuel cell performance by 7.83%. Increasing the reaction temperature increases the thermal energy available in the system and all the molecules in the system move about and vibrate with increased intensity increasing the rate of the reaction. The operating pressure of the fuel cell is varied, and the performance of the fuel cell is observed. The performance of the fuel increases by 2.35% when the pressure is increased by 2 atm on the anode side and 4 atm on the cathode side. The performance of the fuel cell increases due to a better supply of reactants at higher pressures to active sites.