The paper describes an experimental analysis on the effect of cathode flow stoichiometry on the electrical performance of a PEMFC stack. The electrical power output of a PEMFC stack is influenced by several independent variables (factors). In order to analyse their reciprocal influence, an experimental design methodology was adopted in a previous experimental session, to determine which factors deserve particular attention. In this work, a further experimental analysis has been carried out on a very signicant factor: cathode stoichiometry. Its effects on the electrical power of the PEMFC stack have been investigated. The tests were performed on a 3.5 kWel ZSW stack using the GreenLight GEN V I FC Test Station. The stack characteristics have been obtained running a predened loading pattern. Some parameters were kept constant during the tests: anode and cathode inlet temperature, anode and cathode inlet relative humidity, anode stoichiometry and inlet temperature of the cooling water. The experimental analysis has shown that an increase in air stoichiometry causes a signicant positive effect (increment) on electric power, especially at high-current density, and up to the value of 2 stoichs. These results have been connected to the cathode water flooding, and a discussion was performed concerning the influence of air stoichiometry on electrode flooding at different levels of current density operation.
|Titolo:||Experimental analysis of cathode flow stoichiometry on the electrical performance of a PEMFC stack|
|Data di pubblicazione:||2007|
|Digital Object Identifier (DOI):||10.1016/j.ijhydene.2006.08.008|
|Appare nelle tipologie:||1.1 Articolo in rivista|