Electrical and thermal performance analysis of PEMFC with coolant flow field under steady-state condition

A lot of heat is produced during PEMFC's working process. The heat and electricity are highly coupled and need to be analyzed and designed simultaneously. Based on the three-dimensional multi-field couple model considering the coolant channel, this study compared the impact of different thermal boundary setting methods and analyzed coolant key parameters including inlet velocity, temperature, and channel layouts on PEMFC electrical and thermal performance. It was found that adopting a constant temperature boundary in simulation can overestimate electrical performance by 21.8%, while the error of the convective heat transfer boundary is only 1.8%. The voltage loss analysis reveals that the ohmic loss of the proton exchange membrane determined by temperature plays a dominant role, especially after the average temperature of PEM reaches 90 °C. Through this study, the conclusions can be drawn that the PEMFC with widely used Case A coolant could realize a pressure drop reduction of 2.5% and performance improvement of over 4.5%. And the flow rate of coolant should be enough to carry the heat inside PEMFC, or the cell's electrical performance degrade rapidly. When the flow rate is set, a reasonable inlet temperature can realize the optimal electrical and thermal performance of PEMFC.