Experimental investigation of parametric sensitivity analysis on direct-cooling thermal management systems for battery packs

With the rapid development of electric vehicles and energy storage systems, efficient thermal management of lithium-ion batteries has become crucial. This study presents a systematic experimental investigation on a refrigerant-based direct-cooling battery thermal management system, focusing on the interdependence between control parameters and performance indicators. A comprehensive experimental platform was established to examine the effects of compressor frequency, expansion valve opening, and condenser fan speed on multiple performance metrics including energy efficiency, cooling capacity, temperature distribution, and system stability time consumption. Through multi-dimensional sensitivity analysis, the complex relationships between control variables and system indicators were revealed, providing guidance for optimizing control strategies. Under optimal operating conditions, the system achieved a calculated COP (COP_cal)of 8.4, a cooling capacity of 4.04 kW, a maximum temperature difference of 4.0 °C, and reaching stability within 220 s. The findings contribute to a deeper understanding of parameter interdependencies and to the development of efficient control schemes for direct-cooling battery thermal management systems.