Effect of number of channels on performance of PEM fuel cells for serpentine type channel configuration

Abstract

The number of gas flow channels in a serpentine-type channel configuration for Polymer Electrolyte Membrane Fuel Cells (PEMFC) is a critical design parameter. It influences mass transport, pressure drop, and water management, all of which contribute to the overall performance and efficiency of the fuel cell. In this study, different channel number configurations for small active area fuel cell and their role in contributing to a more sustainable energy environment are discussed. The influence of the number of multiple channels on the operational performance was examined in a fuel cell with 25 cm2 of active area. Six different flow channel configurations belonging to the traditional serpentine-designed flow channel were utilized, with multiple inlet-outlet structures. Numerical calculations for pressure, velocity, distribution of reactants (oxygen and hydrogen), membrane water content, and changes in water saturation concentration were conducted using the ANSYS Fluent program. The highest power density of 0.657 W/cm2 was achieved in the single-channel design, resulting in a 14% performance increase compared to the eight-channel design, which exhibited the lowest performance. However, the highest pumping loss due to pressure drop was observed in the serpentine one-channel design at 0.016573 W/cm2. While the pressure drop enhances performance in the same channel design, when constructing a fuel cell stack with a large number of cells, significant difficulties may arise in procuring a compressor capable of providing the desired pressure and flow rate. Therefore, alternative designs with reduced pressure drop need to be considered.