Study of a novel thermal management system using double-layer liquid-cooled plate-coupled PCM under high-rate discharge

An excellent thermal management system (TMS) provides robust guarantee for power batteries operating under high-rate discharge conditions. Specifically designed for cylindrical battery packs, we propose a novel TMS combining phase change material (PCM) with a double-layer cold plate. To enhance the overall performance of the composite thermal management system, the performance parameters of the system are optimized and their effects are compared. Initially, the thermal performance of PCM with different thicknesses was compared, revealing that optimal comprehensive performance was achieved with a PCM thickness of 3 mm, resulting in a temperature difference of 1.52 °C. As the depth of the cold plate and the coolant flow rate increased, the temperature difference showed a tendency of decreasing and then increasing. Furthermore, the choice of PCM and coolant inlet temperature significantly influenced system performance. In particular, the use of RT31 as the phase change material with an inlet temperature of 15 °C was able to control the average temperature of the module at 34.75 °C, and the temperature difference only increased to 2.25 °C. Conversely, by using an inlet temperature of 30 °C was able to reduce the temperature difference to 1.26 °C with a liquid phase fraction of 0.96. Our findings demonstrate that the novel double-layer cold plate can effectively dissipate the heat stored in the PCM, and the designed composite system exhibits superior heat dissipation performance and temperature uniformity.