System simulation on refrigerant-based battery thermal management technology for electric vehicles

Progress in the higher requirements for battery thermal management system (BTMS), a new refrigerant-based BTMS of electric vehicles (EVs) is proposed and analyzed, especially designed for high ambient temperature and high speed dynamic conditions. Based on the vehicle system framework, the thermal response, energy efficiency and irreversibility of the system are discussed hereunder. As indicate by the results, the average temperature of battery module and temperature difference between cells are effectively controlled. In addition, energy analysis is performed under different conditions, including energetic coefficient of performance (COPen) and exergetic coefficient of performance (COPex). The intensification of driving conditions has a negative impact on both COPen and COPex, while the increase of ambient temperature reduces COPen and promotes COPex. Further, the effects of BTMS on the air conditioning (AC), and their consequences are explored. Through a cabin-prioritized control strategy and a series-connected system configuration, this paper aims to improve the system performance and make progresses on the whole vehicle thermal management system.