Numerical and experimental analyses of a novel type PEMFC coolant channel

Temperature is one of the main factors affecting the performance of proton-exchange membrane fuel cell (PEMFC). To make the temperature of the cell more uniform and prevent the occurrence of local hot spots, two novel types of coolant channels (novel A and novel B) are designed and compared with the traditional serpentine channel. Through computational fluid dynamics simulations, the flow field and heat transfer performance of the three coolant channels at different inlet flow rates of the coolant and different wall heat fluxes were examined. The cooling performance of different coolant channels was quantitatively evaluated using five parameters: surface maximum temperature difference, temperature uniformity index (TUI), cooling hydraulic pressure drop (△P), quality factor (QF), and thermal-economic index (TEI). A novel A coolant channel test rig was built to verified the coolant channel model. A two-cells battery model based on the novel A channel was established and verified by the experiment. A 5 kW stack based on the two-cells battery was tested. The deviation between simulation and experiment was within the permissible range. Under the load condition of 54 A, the power of the stack was 5097.81 W, the maximum temperature difference of the coolant plate was 2.13 °C, average temperature of the coolant plate was 61.08 °C, TUI was 1.9 °C,△P was 13.61 kPa, QF was 4.54, TEI was 14.38, and average deviation of voltage generation between single cells was 0.002113V. The stack consisting of 120 cells with the novel A coolant channel showed better cooling performance and ensured the safety of PEMFC stack.