Optimized Cooling System for PEM Fuel Cell Stack Based on Entropy Generation Minimization

Cell temperature in fuel cells is an important parameter which highly affects fuel cell stack efficiency. A suitable cooling system should satisfy an acceptable temperature range. In this research a relevant cooling system for a specified PEM fuel cell stack has been proposed complying with the criteria and cooling requirements of the fuel cell. The effect of various parameters on the entropy generation and temperature distribution in the cooling plates are surveyed. The number of cooling plates, the number of channels in each cooling plate and the channel width is determined. Two flow regimes namely laminar and turbulent flows of the cooling fluid in channels are analyzed and a design methodology is proposed for each regime of flow. The proposed design methodology in turbulent flow will be optimized while the work destruction is minimized. However, the proposed design in laminar flow is not the optimum one but the most efficient between different configurations. The comparison between these two proposed designs show that the turbulent flow has a lower entropy generation. In addition to entropy generation minimization, to have a desirable optimum cooling system, other parameters such as the size of the cooling plates and temperature uniformity inside cooling system have been investigated in this analysis.