Computational Thermal Analysis of Divergent and Convergent Flow Channels for Cooling Plates in PEM Fuel Cells

Abstract

During the operation of polymer electrolyte membrane fuel cells excess heat is generated as a result of electrochemical reactions. This heat raises the temperature of the polymer electrolyte membrane fuel cells, which can damage the membrane. Homogeneity of the temperature through the fuel cell is important in terms of stability and performance. Thermal management is therefore essential and is provided by the cooling channels formed on the bipolar plates or cooling plates. In this paper, a three-dimensional computational analysis of the cooling plate with divergent and convergent flow field designs is carried out. In this context, heat transfer and fluid flow performances of these two different flow fields are considered in terms of temperature uniformity, maximum temperature and pressure drop. Numerical results demonstrated that the more uniform temperature distribution along the fuel cell could be achieved with divergent flow field design. Furthermore, when a divergent design is used, the maximum surface temperature of the cooling plate and the pressure drop between the inlet and outlet of the channel are reduced.