Polymer Electrolyte Membrane Fuel Cell (PEMFC)

Polymer Electrolyte Membrane Fuel Cell (PEMFC) CFD Simulation, ANSYS Fluent Training

Description

The present problem simulates a fuel cell using PEMFC (polymer electrolyte membrane fuel cell) model in porous medium by ANSYS Fluent software. The model consists of two main cathode and anode segments. Each has four layers: a flow collector, a flow channel, a gas distribution area, and a catalytic section, and the space between the anode and cathode layers is filled by the polymer membrane.

The potential value in the anode is assumed to be zero, and as a result, only 0.5 is defined for the cathode electrical potential. Also, at the anode inlet, hydrogen mass fraction is 0.7 and water is 0.3 and oxygen and nitrogen are zero; at the cathode inlet, hydrogen mass fraction is zero and water is 0.14 and nitrogen is 0.66 and oxygen is 0.2.

The Design Modeler software designs the 3-D geometry of the present model. The present model has a symmetrical structure and consists of nine regions of seven specific fluid zones (cathode and anode flow channel, cathode and anode gaseous region, cathode and anode catalytic domain and polymeric membrane), as well as two solid zones.

The solid zone consists of a cathodic and anodic current collector. The mesh of the present model is carried out by ANSYS Meshing software. The mesh type is structured and the element number is 142000.

Methodology: Fuel Cell (PEMFC)

The flow channels carry a mixture of gaseous species, including oxygen, hydrogen, and water. The catalytic part consists of a porous medium with a porosity coefficient of 0.5 and contains mass sources, thermal energy, electrical potential, proton potential, saturated water, hydrogen, oxygen, and water.

The gaseous diffusion zone comprises a porous medium with a porosity coefficient of 0.5 and contains mass sources, thermal energy, electrical potential, saturated water, and hydrogen, oxygen, and gaseous water species. The polymer membrane region also consists of a porous medium with a porosity coefficient of 0.5 and has thermal energy sources and proton potentials.

In this project, the flow equations and the Energy equation are solved. Several modules are used, including Species Transport, Porous & Fuel cell and electrolysis.

Conclusion

This study aims to investigate the fluid behavior and thermal conductivity of a polymer fuel cell and its effect on the mass fraction of gaseous species and the amount of electricity produced in the cell. After the simulation process, results are shown in the form of contours. As expected, hydrogen and oxygen ions transfer through the electrolyte membrane. Besides, the catalyst could hasten the process, so the reactions occur faster and result in an electric current.