Title: Characterisation of two-phase flow and its impact on the performance of a Polymer Electrolyte Membrane fuel cell stack

Authors: G. Karimi, F. Jafarpour, M. Binazadeh, X. Li

Addresses: Department of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Fars, Iran. ' Department of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Fars, Iran. ' Department of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Fars, Iran. ' Department of Mechanical and Mechatronics Engineering at the University of Waterloo, Ontario, Canada, N2L 3G1, Canada

Abstract: Water management is one of the most critical issues for high-performance Polymer Electrolyte Membrane (PEM) fuel cells. A flow network model was developed to study the possibility of two-phase flow inception along the gas flow channels in the cathode side of a PEM fuel cell stack. The conventional Darcy-Weisbach equation and homogeneous flow model are used to estimate the pressure distributions in the network. The corresponding species concentrations as well as the thermodynamic quality distributions are also calculated. The simulation results have revealed that under certain operating conditions, the quality is lower than one for parts of the stack. However, the amount of the liquified water in the stack is not significant to cause a major pressure drop or an appreciable change in the O₂ concentration. Effects of current density and channel diameter on the system quality are also investigated.

Keywords: flow network analysis; mathematical modelling; polymer electrolyte membrane; PEM fuel cells; stack; two-phase flow; water management; gas flow; simulation; current density; channel diameter.

DOI: 10.1504/IJAP.2008.019691

International Journal of Alternative Propulsion, 2008 Vol.2 No.1, pp.26 - 38

Published online: 21 Jul 2008 *