Flow Field Design for Scaled-Up Proton Exchange Membrane Fuel Cell Stack

Abstract

In proton exchange membrane fuel cell, it is essential to maintain the operating parameters within the critical range to achieve improved performance. Moreover, water flooding on the cathode side is one of the significant issues associated with the scaled-up cells at higher power densities, leading to a drop in performance in PEMFC. In this context, this paper describes an alternative flow field configuration used on the cathode side suitable for scaled-up fuel cells. In the present work, simulation and experimental validation are carried out on the scaled-up (384 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) design that consists of a combination of oval and round shape ribs uniformly distributed at the inlet and outlet of the cathode side. The oval and circular pattern introduces the variation in flow direction and creates the turbulence, counter-flow to achieve self-humidification using the product water. The proposed design also ensures the low-pressure drop. Computational fluid dynamics (CFD) is used to simulate operating voltage, velocity, pressure, and temperature distributions at different current densities. The polarisation behavior of a single cell obtained from the simulation is experimentally validated in a fuel cell stack consisting of ten cells. The simulation results are validated against experiments and depict good agreement with the experimental results. The proposed flow field design achieves higher performance, lower pressure drop and uniform reactant distribution. The stack is also studied for various operating pressure (back pressure), and it is observed that the proposed design achieves a current density of 1.05 Acm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> at 0.58 V.