Investigation of oxygen and water distributions in the modified parallel-serpentine cathode channels of a unit polymer electrolyte membrane fuel cell

In this paper, the measurement of water and oxygen distributions along the modified parallel serpentine cathode flow channels has been performed using a gas chromatograph (GC). Generally, it is difficult to directly profile oxygen and water distributions where water concentration nearly reaches saturation levels. Here, the measurement of high levels of water saturation in cathode channels was carefully performed according to operating conditions such as cell voltage and air stoichiometry. GC measurement was also carried out to understand the oxygen and water distributions under channel flooding conditions. In addition, the oxygen and water vapor distributions by GC measurements for the base-line case were compared with computational fluid dynamics (CFD) simulation results. For the entrance of the flow channel, the simulated results show a good agreement with the measured results. However, some discrepancy between calculated and experimental results is found for the flow channels near the cathode outlet.