One dimensional and three dimensional thermal analysis of an air-cooled pem fuel cell

Hydrogen is a clean, renewable energy source and it can be used instead of conventional fossil fuels in order to address environmental problems such as climate change and global warming. Fuel cells that can utilise hydrogen are known as environmentally friendly systems as they generate electricity by releasing water without any carbon emissions. Proton Exchange Membrane (PEM) fuel cells have significant potential thanks to their low operating temperatures, high power densities, and compactness. Although the efficiency of a PEM fuel cell system depends on the type and operating temperature, it is generally higher than other hydrocarbon fuel based systems. The efficiency of a PEM fuel cell is related to the cell temperature and therefore, thermal management is crucial to maintain high system efficiency. Mathematical modelling of the thermal behaviour of PEM fuel cells is essential for the management of the system efficiency. In this study, the thermal behaviour of a single cell is determined by using one dimensional and three dimensional models by calculating the total heat generation of a fuel cell stack connected to a power measurement instrument and operated at variable current demands. The one dimensional thermal model calculated the maximum temperature in a cell under different current demands using thermodynamic heat generation calculation method. The three dimensional thermal model included the geometric details of the cell and calculated the effects of different current demands, change in ambient temperature and change in convection heat transfer coefficient on the maximum cell temperature. MATLAB/Simulink was used to generate the one dimensional thermal model, and ANSYS was used to create the three dimensional thermal model. The cell was designed by using SpaceClaim. Furthermore, an experimental test rig was designed and commissioned to compare the model results against with the experimental results. Horizon H-500XP PEM fuel cell was used. The results showed that the deviation for the maximum cell temperature between the model and the experimental results ranged from 5% to 6,7% for the one dimensional model and from 3,1% to 9,1% for the three dimensional model. It was detected that the increase in current and ambient temparature significantly increased the cell temperature. It was observed that the maximum cell temperature differences resulting from the change in convection heat transfer coefficient increase as the current demand increases.