PEMFC and SOFC fuel cells - Heat and mass transfer

Two articles cover PEMFC and SOFC fuel cells: system description and management [ [BE 8 595] ] and heat and mass transfer [BE 8 596].

In this second article, we will focus on the thermal modeling of PEMFCs (proton exchange membrane fuel cells) and SOFCs (solid oxide fuel cells). Controlling the temperature within a cell and, more generally, within a stack of cells is key to ensuring proper operation and extending the fuel cell’s lifespan. By its very nature, a fuel cell consists of solid components (electrodes and membrane) and fluid components (gases and a gas or liquid cooling system). Modeling must therefore account for both of these components and their interfaces. The techniques used differ; for example, the nodal method is used for the solid components, while the finite difference method is used for the gases.

These reactions are accompanied by mass transfer and changes in species concentrations, which must be taken into account to accurately model the phenomena. The same applies to water transfer through membranes and diffusers. The coupling between the two methods—the nodal method and the finite difference method—must account for the direction of gas flow; resulting in two main configurations: co-current or counter-current. The modeling of a single cell must obviously be extended to the entire stack. Thermal modeling of high-temperature SOFC stacks follows the same approach. We will provide only a general overview here.