Experimental Research on Direct Cooling Thermal ManagementSystem for Multi-Box Battery Packs

As the power density of lithium-ion batteries steadily advances and high-power fast charging technologies evolve, the design of battery thermal management systems has emerged as a pivotal and challenging area of research. This study introduces a direct cooling thermal management system for multi-box battery packs, utilizing roll-bond cold plates，and conducts experimental research on the system's performance under different operating conditions. The experimental results show that at a charging rate of 0.5 C and a compressor speed of 2400 r/min, the system's average Coefficient of Performance (COP) can reach 5.83, the cold plate's maximum dimensionless loss coefficient is 6.27%, and the maximum temperature difference between cold plates is 1.90 °C. Notably, the temperature difference between the plates escalates with an increase in compressor speed and the cold plate's thermal load, peaking at 3.99 °C during the tests. Concurrently, the system's COP exhibits a decreasing trend with the acceleration of the compressor, achieving a maximum of 7.41 throughout the duration of the experiments.