Modeling Reaction and Diffusion Processes of Fuel Cells within Modelica

Abstract

The field of fuel cell (FC) technology offers a challenging and rewarding application for the Modelica language because it is highly multi-disciplinary and it entails physical phenomena (e.g., catalysis) that are not fully understood. Modelica is a valuable platform from which to explore FCs because it is appropriate for the representation of physical interactions. This paper describes elements of a FC library which has been developed in Modelica. The goal of the modeling effort is to take full advantage of the physically representative nature of the Modelica language. To this end, it is important for the models to be consistent and explicit in terms of energy and species balances. The paper emphasizes the representation of diffusion and electrochemical processes. In these areas, the traditional approach is to represent empirically observed behavior, and this is not necessarily rigorous from the standpoint of energy and species balances. To describe the diffusion and electrochemical processes in a form that is suitable for Modelica, alternative and possibly more physically fundamental model equations have been developed.