Simulation of battery simultaneous cooling based on the dual fluid medium system

Abstract

The battery thermal management system (BTMS) based on refrigerant cooling can cope with high battery heat production even in the case of high ambient temperature, but the economy is poor. A novel BTMS called dual flow medium system (DFMS) had been proposed in previous studies to improve the economy of refrigerant-based BTMS, including refrigerant and coolant in parallel for battery cooling. Based on a validated simulation system, this study presents and analyzes a new operation mode of the DFMS called simultaneous cooling, in which the refrigerant and coolant cool the battery simultaneously. First, the transient cooling process was studied under different ambient temperatures, compressor speeds, and coolant flow rates. The results show that simultaneous cooling can reduce the average battery temperature by 2.66 °C more than using only refrigerant for battery cooling, and the maximum temperature difference between batteries can reach 0.33 °C. Then different coolant flow control methods are proposed and compared under the premise of constant temperature mode. The results show that compared with only refrigerant cooling, the optimal coolant flow control method can reduce the maximum temperature difference between the batteries by 31.94 % but with an extra 2.24 % power consumption.