Fuel Cell Dynamics

Proton exchange membrane fuel cells (PEMFCs), owing to their high energy efficiency, low emission, and low noise, are widely considered as the most promising alternative power source in the 21st century for automotive, portable, and stationary applications. A typical PEMFC consists of several distinct components: the membrane electrode assembly (MEA) comprising a proton conducting electrolyte membrane sandwiched between two catalyst layers, the porous gas diffusion layers, and the bipolar plates with embedded gas channels. In the anode catalyst layer, the hydrogen oxidation reaction (HOR) splits the hydrogen into electrons, which are transmitted via the external circuit, and protons, which migrate through the membrane and participate in the oxygen reduction reaction (ORR) in the cathode catalyst layer to recombine with oxygen and produce water and waste heat.

• Computational domain and mesh

• Hydrogen concentration on the anode side

• Oxygen concentration on the cathode side

• Water concentration on both sides

• Water distribution in MEA on both sides

• Distributions of temperature, protonic and electronic potentials

• Distributions of velocity field and pressure

• Convergence history with/without the advanced technique

• A fuel cell stack

A Simplified Fuel Cell Model We propose a model of liquid and heat flux, ignoring the gas dynamics. More specifically we assume that the pressure and vapour pressure are constant and solve for the water volume fraction and the temperature as functions of space and time. The water motion is driven by capillary pressure, and a heat flux is generated by boundary conditions. The two equations are coupled by condensation, which exchanges heat for liquid, generating a liquid flux opposite that of the heat flux. Numerical simulation is done with the adaptive finite element method