Adaptability enhancement of mini-channel cold plate for cylindrical battery module under various ambient temperatures

Adaptability enhancement of battery thermal management system (BTMS) to various ambient temperatures is important to ensure operation safety of electrical vehicles considering the intensification of greenhouse effect. However, for BTMS based on mini-channel cold plate, corresponding researches are rare and existing knowledge is insufficient to provide effective guidance for the design of BTMS adaptable to various temperature conditions. In this work, systematically numerical investigations are performed to compare cooling performances of mini-channel cold plate under various ambient temperatures ranging from 25 °C to 45 °C. Thorough analyses are provided to clarify the underlying temperature evolution mechanisms of the cylindrical battery module during the discharge process in terms of both temperature rise and temperature uniformity. Significant peaks are witnessed in the time-dependent curves of maximum temperature difference at high ambient temperatures. Thus, extended studies are carried out to elucidate the influences of coolant inlet temperature, ambient convection coefficient and coolant flow rate on the intensity and duration time of the maximum temperature difference peak. Based on the results, a feasible strategy combining gradient-reduced coolant inlet temperature with appropriately decreased flow rate is proposed to realize satisfactory temperature uniformity for the BTMS working at extreme high ambient temperature (above 40 °C).