The Structural Optimization Design and Temperature Uniformity Promotion of Battery Energy Storage Station Using Liquid-Air Combined Cooling Method

Thermal management of liquid-cooled battery energy storage stations (BESSs) is becoming a hot research topic. At present, a liquid cooling plate in the heat management system is primarily located at the bottom of batteries. However, The battery temperature uniformity deteriorates owing to the poor heat transfer at the battery bottom, which affects the service life of the battery. Thus, this study proposes a battery liquid flow inter-wall heat transfer structure by CFD modeling. Under the 2P frequency modulation condition, the results of simulation showed that the maximum temperatures difference and average temperature of the battery cluster were 6.5 and 300.8 K at the end of the discharge period, respectively. In order to further improve the uniformity of temperature distribution in the battery cluster system, a liquid-air combined thermal management system was designed based on the battery liquid flow inter-wall heat transfer structure. Four kinds of liquid-air structures a, b, c and d are proposed. In the optimal structure d, at the end of the discharge period, the maximum temperature difference of the battery cluster was 1.3 K, which exhibited an effective improvement of 80.2% compared with that of the liquid flow inter-wall heat transfer structure. The proposed liquid-air combined thermal management system effectively restrains the unacceptable heat transfer at the heat transfer terminal and deterioration of single battery temperature; in addition, it can extend the battery cycle life and helps improve the use economy of BESSs.