Experimental Studies on the Influence of Operational Parameters on the Cold Start of a 2 kW Fuel Cell
BEGOT ; HAREL ; KAUFFMANN
Type de document
ARTICLE A COMITE DE LECTURE REPERTORIE DANS BDI (ACL)
Langue
anglais
Auteur
BEGOT ; HAREL ; KAUFFMANN
Résumé / Abstract
In this paper, experimental investigations on the influence of operational parameters on PEM fuel cell cold start are presented. The effect of current density, stack impedance at 1 kHz prior to start, as well as gas flow rate, gas pressure, coolant flow rate and surrounding subfreezing temperature are studied. The experimental apparatus is briefly described. It includes a main unit at room temperature and a smaller separate unit in a climatic chamber. Low current density, high impedance prior to start, moderate subfreezing temperature (–5 °C), high gas flow rate, low gas pressure and low coolant flow rate are found to have a positive impact on the cold start performance. Combining these parameters, self start-up of the fuel cell without additional energy is achieved at –5 °C in 30 min. The whole set of observations leads to the following hypotheses on freeze mechanism: in the first phase, dry membranes and low current lead to a transient phase of membrane humidification. Then, in the second phase, ice clogging of the active layers occurs. In the third phase, a variable quantity of the produced water reaches the gas diffusion layers and channels.
Source
Fuel Cells - From Fundamentals To Systems, num. 2, pp 138-150 p.
Editeur
WILEY
