Thermal performance of liquid-cooling systems for PEM fuel cells: A CFD study

A comprehensive 3D computational fluid dynamics (CFD) model is developed to explore the thermal performance of a PEM fuel cell liquid-base cooling system. In previous studies, the models were developed to simulate a single cooling plate. While in this study, the model consists of a bipolar plate with gas diffusion and catalyst layers. The heat generation mechanism in the PEM fuel cell stack and the liquid cooling method - to keep their operating temperature in the desired range - are presented and discussed. Fully three-dimensional results of the temperature distribution, velocity, and pressure-flow field are presented and analysed, focusing on the physical insight and fundamental understanding. The index of uniform temperature (IUT) through the bipolar plate is also produced to assess the degree of uniformity of temperature profile through the bipolar plate. The results show that increasing Reynolds number (Re) leads to a lower coolant’s temperature difference between the outlet and inlet of the flow channel. However, increasing Re increases the pressure drop across the flow channel and consequently increases the pumping power consumed to circulate the coolant. The present model is valuable for further development in the cooling flow field design and choosing the coolant used in the PEM fuel cell stacks.