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Institut für Wasserbau - IWS

Selected Topics and International Network Lectures

Druckansicht
 
Dienstag
27.11.2007
16:00 Uhr
Dr.-Ing. Steffen Oliver Ochs
Lehrstuhl für Hydromechanik und Hydrosystemmodellierung, Institut für Wasserbau, Uni Stuttgart

Simulation of multiphase multicomponent processes in PEM fuel cells

The development of new alternative power sources/supplies is an important task nowadays. Polymer electrolyte membrane (PEM) fuel-cells currently are intensively investigated and improved for applications. This requires a profound understanding of the physical and electrochemical processes elapsing in fuel cells. It has been found that the kinetics of the oxygen reduction at the cathode is a limiting factor for the performance of fuel-cells. The transport of oxygen to the cathode through its porous diffusion layer occurs in a predominantly diffusive manner. The generation of liquid water at the cathode-site constrains this oxygen transport to the reaction layer. Thus, an efficient water management in the cathode diffusion layer is necessary to improve the performance of the fuel-cell.

In the seminar we present a multiphase multicomponent model originally developed at LH2 for the simulation of non-isothermal multiphase processes in the subsurface and the modifications necessary for modeling multiphase processes in the diffusion layer of PEM fuel-cells. The results of two studies one on the influence of capillary pressure and another on the effect of different flow regimes on the system behavior will be discussed.