Performance Investigation of PCM/Pin Fin Coupled Battery Thermal Management System

Abstract

The low thermal conductivity of phase-change materials (PCMs) hampers the commercialization of PCM cooling battery thermal management systems. Further reduction of the thermal resistance between the PCM and batteries is still a challenging problem. In this study, a PCM / pin fin design is proposed. ANSYS Fluent was used to construct the model of PCM / pin fin design. The SIMPLE algorithm and the second-order upwind scheme were used to solve the momentum and energy equations. Compared with the traditional pure PCM and PCM/plate fin designs, the maximum temperature of the battery (T max ) was lower for the PCM/pin fin design because the heat transport from the batteries to the PCM was enhanced owing to the pin fin with a larger heat-transfer area. T max for the pure PCM configuration reached 55.76°C after discharge, exceeding the upper-limit temperature of 55°C. In contrast, for the PCM/pin fin design, T max was only 53.44°C. This indicates that the PCM/pin fin design effectively alleviates the heat accumulation of the battery and successfully maintains the battery temperature within a safe range. The effects of PCM thickness and fin section area on thermal behavior were investigated. It was found that the decrease of fin cross-sectional area can significantly reduce T max . When the fin cross-sectional area is 1 mm 2 , the T max is only 51.07°C. In addition to control T max under 55°C, the minimum PCM thicknesses were 3.71, 2.89, and 2.38 mm for pure PCM, PCM/plate fin, and PCM/pin fin, respectively. Thus, compared with the other designs, in the PCM/pin fin design, fewer materials are required, the weight of the modules is reduced, and the energy density is improved.