Modeling, Parameter Identification, and Validation of Reactant and Water Dynamics for a Fuel Cell Stack

Abstract

This paper describes a simple two-phase flow dynamic model that predicts the experimentally observed temporal behavior of a proton exchange membrane fuel cell stack and a methodology to experimentally identify tunable physical parameters. The model equations allow temporal calculation of the species concentrations across the gas diffusion layers, the vapor transport across the membrane, the degree of flooding in the electrodes, and then predict the resulting decay in cell voltage over time. A nonlinear optimization technique is used for the identification of two critical model parameters, namely the membrane water vapor diffusion coefficient and the thickness of the liquid water film covering the fuel cell active area. The calibrated model is validated for a 24 cell, 300 cm2 stack with a supply of pressure regulated pure hydrogen.