Numerical Comparison of the Performance of Four Cooling Circuit Designs for Proton Exchange Membrane Fuel Cells (PEMFCs)

Polymer Electrolyte Membrane Fuel Cell (PEMFC) are among the most promising technologies as energy conversion devices for the transportation sector due to their potential to eliminate, or greatly reduce, the produc- tion of greenhouse gases. One of the current issues with this type of technology is thermal management, which is a key aspect in the design and optimization of PEMFC, whose main aim is an effective and balanced heat removal, thus avoiding thermal gradients leading to a cell lifetime reduction as well as a decrease in the output performance. In addition, a uniform temperature distribution contributes to the achieve- ment of a uniform current density, as it affects the rate of the electrochemical reaction. This is made even more challenging due to the low operating temperature (80°C), reducing the temperature difference for heat dissipation, and leaving a critical role to the design and optimization of the cooling circuit design. In this paper, a three-dimensional and multi-physics CFD approach is used to compare four different liquid cooling flow fields within the bipolar plates, using a conventional cooling fluid. Several typical cooling flow rates will be tested and equalized among all the considered cases, in order to carry out consistent comparisons. Numerical analyses will include Index of Uniform Temperature (IUT), minimum and maximum temperature gradient, coolant circuit pressure drop, thermal power absorbed by the coolant and performance of the cell, thus providing a detailed and comprehensive overview of a PEMFC thermal survey. The study paves the way for a conjugate fluid-dynamic/thermal characterization of a full PEMFC stack, thus constituting a fundamental step towards a CAE-based engineering of fuel cells.