The experimental validation of a simplified PEMFC simulation model for design and optimization purposes

Abstract

Geometric design, including the internal structure and external shape, considerably affect the thermal, fluid and electrochemical characteristics of a polymer electrolyte membrane fuel cell (PEMFC), which determines the polarization curves as well as the thermal and net power responses. In order to predict the response of PEM fuel cells according to the variation of manufacturing materials physical properties, operating and design parameters, a reliable simulation model (and computationally fast) is necessary, which accounts for the power losses due to pressure drops in the gas channels. In this paper, a simplified and comprehensive PEMFC mathematical model introduced in previous studies is experimentally validated. Numerical results are obtained with the model for an existing set of ten commercial unit PEM fuel cells. The model accounts for pressure drops in the gas channels, and for temperature gradients with respect to space in the flow direction, and current increase that are investigated by direct infrared imaging, showing that even at low current operation such gradients are present in fuel cell operation, and therefore should be considered by a PEMFC model, since large coolant flow rates are limited due to induced high pressure drops in the cooling channels. The computed polarization and power curves are directly compared to the experimentally measured ones with good qualitative and quantitative agreement. The combination of accuracy and low computational time allow for the future utilization of the model as a reliable tool for PEMFC simulation, control, design and optimization purposes.