A numerical study on uniform cooling of large-scale PEMFCs with different coolant flow field designs

A uniform temperature distribution is important to obtain better control and higher performance of polymer electrolyte membrane fuel cells (PEMFCs). In PEMFCs, more than half of the chemical energy of hydrogen is converted into heat during the electrochemical generation of electricity. If not being properly exhausted, this reaction heat overheats the PEMFCs and thus impairs their performance and durability. In general, large-scale PEMFCs are cooled by liquid water that circulates through coolant flow channels in bipolar plates or in dedicated cooling plates. In this study, detailed fluid flow and heat transfer in large-scale cooling plates with 18 cm × 18 cm square area was simulated using a commercial computational fluid dynamics (CFD) code. Based on the CFD simulations, the performances of six different coolant flow field designs were assessed in terms of the maximum temperature, temperature uniformity, and pressure drop characteristics. The results demonstrated that multi-pass serpentine flow field (MPSFF) designs could significantly improve the uniformity of temperature distribution in a cooling plate compared with the conventional serpentine flow field designs, while maintaining the coolant pressure drop similar.

Research highlights
► Several coolant flow fields were numerically assessed for uniform cooling of large-scale PEMFCs.
► Serpentine flow fields led to more uniform temperature in PEMFCs than parallel straight flow fields.
► Multi-pass serpentine flow fields (MPSFFs) showed better cooling performance over conventional serpentine flow fields.
► Temperature uniformity could be further enhanced by controlling flow rate in each coolant path of MPSFFs.