ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Hot spot identification in PEM fuel cell and its purging strategies

Ramakant Gadhewal, Sunil Kumar Thamida, Venu Vinod Ananthula, and Venkata Suresh Patnaikuni

Department of Chemical Engineering, National Institute of Technology, Warangal, India

E-mail: pvsuresh@nitw.ac.in

Received: 5 August 2021  Accepted: 10 October 2021

Abstract:

In this numerical study, it has been shown that a hot spot would be formed close to the entrance of the PEM fuel cell cathode side near the membrane layer. COMSOL Multiphysics was used to conduct time-dependent simulations on a 2D model of the cathode portion of the PEM fuel cell. The startup dynamics show that hot spot build-up and its extent are time taking processes. Two strategies are proposed to mitigate hot spots—first, introducing bumps in the reactive gas flow channel and, secondly, supplying a higher fraction of nitrogen relative to oxygen on the cathode side of the straight flow channels. Parametric studies on both techniques were conducted by varying the size of the bump, the amplitude of the cyclic nitrogen gas composition, and the Pt catalyst fractional coverage. Both strategies significantly decrease hot spot temperature, which effectively affects the membrane layer endurance. Finally, an approach that combines the two proposed techniques is also analyzed.

Keywords: PEM fuel cell; Transient-state simulation; Oscillating nitrogen gas supply; Hot spot; Purging; Bumped channel

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01932-0

Chemical Papers 76 (2) 1199–1211 (2022)