To provide a framework for interpreting experimental measurement and the effect of experimental and operational variables, a rigorous model to predict fuel cell performance is under development, which incorporates mass and heat transfer combined with electrochemical kinetics. This model extends existing models in the fuel cell literature and is adapted to both PEM and solid oxide fuel cells. The model is being incorporated into a commercial software package (COMSOL) to facilitate access as a tool for UK industry.

The physical processes involved in fuel cells are highly complex at the microscopic level and in the multi-layer structure involve a complex interplay of mass, momentum, energy, entropy and electrical transfer. It is important to establish best understanding of all the processes at the microscopic level but in modelling the system the discreteness of the microscopic processes cannot be fully reproduced and are usually represented by continuum relationships in quasi-homogenous media. In that context the NPL concept was to develop a more rigorous model of a fuel cell based on non-equilibrium thermodynamics. The model will form a basis for linking performance to key system variables.

A key feature of the NPL fuel cell research programme is the development of in situ measurement techniques to support the model.

Objectives

• Development of improved model of reaction kinetics and mass and heat transfer in a fuel cell as a framework for understanding and predicting the effect of experimental and operational variables
• Incorporation of model into existing commercial software package (COMSOL)

Outputs

• Improved model of PEMFC membrane and active layers in the form of a COMSOL module
• Non-isothermal model of fuel cell performance in the form of a COMSOL module

For more information, please contact Gareth Hinds.