Cooling System Topology of High-Endurance Dual Stack Proton Exchange Membrane Fuel Cell System for Heavy Duty Trucks

The adoption of proton exchange membrane fuel cell (PEMFC) technology in heavy-duty trucks represents a promising solution for addressing the pressing issues of emissions and sustainability in the transportation sector. Achieving high-endurance operation is critical for the success of these systems, and effective cooling is central to this goal. This paper explores innovative cooling topologies and control strategies designed to extend the endurance and operational longevity of dual PEMFC stack systems in heavy-duty truck applications. To address these issues, a comprehensive analytical model for a dual PEMFC stack system is developed to assess the heat generation within the fuel cell stacks, enabling a meticulous evaluation of the cooling requirements. Two strategies for controlling coolant bypass flow are evaluated, one based on coolant temperature and the other based on stack temperature, during dynamic operation. Three different topologies are designed to achieve efficient cooling systems, and their impact on parasitic power and energy consumption is examined. The results suggest that control strategy in which the bypass valve open ratio is controlled based on the stack temperature, performs better in regulating the fuel cell operating temperature precisely. Among the various topologies, the distributed topology which involves setting up two independent cooling systems for each stack, significantly reduces energy consumption. In particular, it saves up to 71% of energy consumption compared to the integrated topology, where a single cooling system is used for both stacks.