Effects of operating conditions on the performances of individual cell and stack of PEM fuel cell

In this study, experiments were carried out to study the effects on the performances of individual cell and stack of PEM fuel cell. In the experiment, there are four key operating conditions that affect the cell performance, and they are gas humidification temperature, cell temperature, assembled torsion, and gas flow rate. A 5-cell stack of PEMFC was used to measure the voltage and current density for individual cell in this experiment. Results reveal that the performances of the center fuel cells are relatively lower than those of the cells on both sides of the stack. It is also shown that stack performance increases with the increase in the anode humidification temperature as well as the center cell of the stack. As for the effect of cell temperature, results indicate that stack performance increases with the increase in cell temperature. It is also disclosed that the performances of individual cell and stack do not change with the increase in the anode gas stoichiometric ratio, but increase with the increase in the cathode gas stoichiometric ratio. In addition, the experiment results also show that the whole stack's performance is enhanced with the increase in the assembling torsion. (C) 2008 Elsevier B.V. All rights reserved.