Experimental Investigation of the influence of polymer electrolyte membrane fuel cell operating conditions on its performance and water management

In this research, the effect of anode stoichiometry, cathode stoichiometry and temperature of inlet gases on water management and performance of a PEM fuel cell is studied by means of DOE (Design of Experiments) and direct visualization. In order to visualize the liquid water accumulation in cathode flow channels, a transparent PEM fuel cell is designed and manufactured in fuel cell research laboratory of Amirkabir University of Technology. Design of experiments is based on response surface method and central composite design. Cell’s performance is recorded over the test time and a video is simultaneously captured from its transparent cathode flow channels. Then, a digital image processing technique is used to detect and quantify channel areas that are occupied by liquid water. Area of regions containing liquid water is divided by total area of flow channels to calculate a parameter called water coverage ratio (WCR) which is then used to study flooding phenomenon. Results show that increase in cathode stoichiometry, anode stoichiometry and gas inlet temperature leads to a decrease in WCR. Also, WCR lies between 1.8 and 4.3 when an optimized produced power is reached. It is also proved that anode and cathode stoichiometry has to be minimized to reach the maximum produced power at a high inlet gas temperature.