Recent advancement on thermal management strategies in PEM fuel cell stack: a technical assessment from the context of fuel cell electric vehicle application

Effective thermal management strategy for the polymer electrolyte membrane fuel cell (PEMFC) stack is critical in maintaining the overall stack efficiency and durability. The present assessment critically explores the recent developments (predominantly last decade) in thermal management strategies of PEMFCs, which encompasses an in-depth analysis of the thermodynamics, corresponding effects on components of PEMFC and the waste heat recovery system. In general, the operating temperature range of a PEMFC is 60-80 degrees C. Entropy consequence and irreversible transport mechanisms of the reactants are the major contributions to heat generation. Air cooling is employed for compact stacks of less than 5 kW and water cooling is favored for stacks greater than 5 kW. Cooling using nanofluids enables better cooling efficiency than water while downsizing the size and weight of the system. Phase change cooling strategy to attain greater heat removal capacity is broadly employed for stacks greater than 10 kW, which is beneficial in a compact size of the cooling system contrasted to the water cooling system. Passive cooling methods employing vapor chamber, heat pipes and heat spreaders used were another cooling system for stack power ranges between 5 and 10 kW which have the benefit of reduced parasitic losses. In addition to thermal management strategies, integral challenges associated with each thermal management strategy is identified. Discussion on cold start thermal management of fuel cell electric vehicles was provided. Finally, the waste heat recovery system of energy efficiency and overall future prospectus for the betterment of thermal management of PEMFC is emphasized.