Performance simulation and key parameters in-plane distribution analysis of a commercial-size PEMFC

Abstract

Commercial fuel cell stacks often have a large electrode area to obtain a high power output. Uniformity in-plane distribution of vital physical quantities plays a key role in improving cell performance and avoiding degradation. In this study, a three-dimensional two-fluid multiphase model is adopted to analyze the in-plane distribution characteristics of key parameters (reactant concentration, temperature, local current density, and membrane water content) for a large-scale PEMFC with an active area larger than 300 cm2. The particular feature of the PEMFC studied is that there are gap zones near the edge between the bipolar plate and gas diffusion layer and membrane. The results show that for the structure without gap zones, the cell performance improved by about 1%. The non-uniformity of cathode reactant distribution is generally higher than that of the anode; The non-uniformity of temperature in the x direction is higher than that in the y direction (flow-direction). With the increase of average current density, the temperature in the membrane increases, and the membrane dehydrates gradually. The flow direction of coolant has a significant impact on the cell performance. When coolant is in the same direction as hydrogen, the cell performance decreases by about 3.75% at 0.8 A/cm2.