Theoretical Model for the Optimal Design of Air Cooling Systems of Polymer Electrolyte Fuel Cells. Application to a High-Temperature PEMFC

The cooling system of a high-temperature PEM fuel cell with a nominal electric power of 1.5kW for a combined heat and power unit (CHP) has been designed using a thermochemical model. The 1D model has been developed as a simple, predictive, and useful tool to evaluate, design, and optimize cooling systems of PEM fuel cells. As proved, it can also be used to analyze the influence of different operational and design parameters, such as the number and geometry of the channels, or the air flow rate, on the overall performance of the stack. To validate the model, predicted results have been compared with experimental measurements performed in a commercial 2kW air-forced open-cathode stack. The model has then been applied to calculate the air flow required by the designed prototype stack as a function of the power output, as well as to analyze the influence of the cooling channels configuration (cross-section geometry and number) on the heat management. Results have been used to select the optimum air-fan cooling system, which is based on compact axial fans.