Besides the fact that the Proton Exchange Membrane Fuel Cells (PEMFCs) have become the industrial norm of today, the thermal management in PEMFCs is still challenging. Therefore, the present study delves deep understanding of the issue of thermal management and summarizes the relevant research studies that evaluate the efficiency of serpentine flow fields (SFFs) to other flow configurations for thermal management in PEMFCs. The current research explores the variety of aspects of SFFs i.e., temperature uniformity, cooling efficiency, pressure drop, and overall thermal performance to guide future design optimizations and practical implementations of SFFs. The study in hand also discusses developments in SFFs such as., Multi-Pass Serpentine Flow Fields (MPSFFs) and new hybrid designs that include a combination of traditional serpentine and other flow patterns to decrease pressure drop and increase net performance. The findings of various studies show that serpentine flow fields outperform alternative designs in coolant distribution, heat transfer efficiency, and operating temperature stability. Based on the findings, the present study recommends future research options, highlighting the need to include economic and environmental concerns in flow field (FF) design, as well as investigating the use of developing materials and technologies to improve PEMFC performance.

Proton-exchange membrane fuel cells (PEMFCs) stand out for their exceptional efficiency, high power density, and zero emissions, as they produce merely heat and water as byproducts. Appropriate and robust thermal management is the key to ensuring the maximum efficiency of the fuel cell (FC) as its optimum operating temperature is 70~80 °C. The current study was designed for the parametric evaluation of coolant channels (CCs) based on the multi-pass serpentine flow field (MPSFF) to investigate the relationship between channel geometry and thermal performance in PEM fuel cells, offering novel insights into optimal design configurations for improved thermal management. Six 3D computational models of PEMFCs with varying numbers of coolant channels were created and evaluated using COMSOL 6.2. The acquired results suggested that longer channel lengths with more serpentine turns cause the maximum number of hot spots around turns and offer a maximal pressure drop, whereas increasing the number of channels results in a uniform thermal distribution and leads to a minimal pressure drop. The findings indicate that systematic variations in geometrical configurations of MPSFFs can significantly enhance thermal uniformity and minimize the pressure drop, offering valuable insights for improving the efficiency of PEMFCs.

Wave-like channels can intensify reactant transport in high-temperature proton exchange membrane fuel cells (HT-PEMFCs), but pressure loss and CO poisoning are strongly coupled under reformate operation. A three-dimensional steady-state model was developed for a methanol-reformate-fed HT-PEMFC with a local CO-coverage correction and evaluated against polarization measurements; the correction reduced the mean relative error from 5.32% to 2.51%. The effects of wave number N, minimum channel height H, and wavelength L were resolved through species transport, current density, pressure drop, and CO coverage. Increasing N strengthened repeated flow acceleration and near-wall reactant exchange, raising the maximum gross power density by up to 4.33%. Decreasing H accelerated the channel flow from 2.67 to 9.29 m/s but increased the cathode pressure drop from 24.24 to 726.70 Pa, revealing a non-monotonic transport–resistance trade-off. L produced only minor changes because it altered disturbance spacing without changing constriction strength. One-factor cases and 24 Latin-hypercube samples provided 36 high-fidelity geometries for response-specific surrogates. Coupling these surrogates with NSGA-II generated a Pareto front. The design with N = 9, H = 0.044 cm, and L = 0.17 cm was selected as the high-net-power Pareto solution because it yielded the highest predicted pressure-loss-corrected output. Relative to a straight channel, this design increased the maximum gross power density and maximum corrected net power density by 9.34% and 9.30%, respectively, while maximum local CO coverage rose by 3.12%. The results identify minimum channel height as the governing geometric parameter and provide a mass-transfer-based design rule for reformate-fed HT-PEMFC channels.

Wave-like channels can intensify reactant transport in high-temperature proton exchange membrane fuel cells (HT-PEMFCs), but the accompanying pressure loss and CO poisoning are strongly coupled under reformate operation. A three-dimensional steady-state model was therefore developed for a methanol-reformate-fed HT-PEMFC with a local CO-coverage correction and compared with baseline polarization measurements; the correction reduced the mean relative error from 5.32% to 2.51%. The effects of wave number N, minimum channel height H, and wavelength L were resolved through species transport, current density, pressure drop, and CO coverage. Increasing N strengthened repeated flow acceleration and near-wall reactant exchange, raising the maximum gross power density by up to 4.33%. Decreasing H accelerated the channel flow from 2.67 to 9.29 m s−1 but increased the cathode pressure drop from 24.24 to 726.70 Pa, revealing a non-monotonic transport-resistance trade-off. L produced only minor changes because it altered disturbance spacing without changing constriction strength. One-factor cases and 24 Latin-hypercube samples provided 36 high-fidelity geometries for response-specific surrogates. NSGA-II generated a three-objective nondominated set, from which the design with the highest estimated net power density, calculated from the predicted gross power density and pressure drop, was selected (N = 9, H = 0.044 cm, L = 0.17 cm). Relative to a straight channel, this design increased the maximum gross power density and the estimated pressure-loss-corrected power-density indicator by 9.34% and 9.30%, respectively, while maximum local CO coverage rose by 3.12%. The results identify minimum channel height as the governing geometric parameter and provide a mass-transfer-based design rule for reformate-fed HT-PEMFC channels.