Advancing heat management in proton-exchange membrane fuel cells through hybrid nano-composite phase change materials

Abstract

Heat management challenges in proton-exchange membrane fuel cells (PEMFC) leads to performance degradation, particularly during operational fluctuations and vehicle downtime. This study examines the use of Nano-additive phase change materials (PCMs) as an innovative approach to thermal management in PEMFCs. It addresses a research gap, as PCMs' advantages in batteries and electronics are well-known, but their application in PEMFCs remained relatively unexplored. Hence, using the ChtMultiRegionFoam solver from OpenFOAM, two heat transfer aspects in PEMFCs are studied. The first examines PEMFC cooling under normal conditions, combining liquid cooling with a hybrid Nano-composite phase change material (HNCPCM). The results indicate the HNCPCM cools the PEMFC for 11 min before reaching saturation, after which liquid cooling starts. Moreover, with HNCPCM, the PEMFC's thermal efficiency and temperature uniformity enhance by 7.04 % and 39.76 %, respectively. Therefore, the HNCPCM contributes to cooling as the temperature and voltage fluctuate under real conditions. The second aspect evaluates PCM and insulation to maintain the PEMFC stack's operating temperature range (OTR) during downtime. Using 4 mm PCM and 11 mm insulation, the stack stays within the OTR for nearly 4 h, extending the OTR duration by 49.2 %. Consequently, the waste energy stored by PCM ensures the stack remains within the OTR, averting performance degradation upon restart.