Experimental study on the thermal management performance of a power battery module with a pulsating heat pipe under different thermal management strategies

Given the power battery module for electric vehicle kinetic energy system in a high-temperature environment and large rate discharge process, there are thermal safety risks such as battery easy overheating and temperature uneven, this paper takes 23Ah LFP power battery module as the research object to build the system. The system uses TiO2 nanofluid pulsating heat pipe (TiO2-CLPHP) and cooling fan as heat conduction and heat dissipation components and conducts thermal monitoring of power battery modules through a thermocouple built into the power battery. The thermal management strategy of optimal thermal efficiency and optimal thermal management strategy of energy consumption proposed in this paper is used to solve the thermal management problem of power battery modules. On this basis, the performance tests of the power battery module thermal management system with optimal thermal efficiency and optimal energy consumption were carried out under different thermal management performance testing conditions, and the energy consumption and economy of the power battery module thermal management system under the two thermal management strategies were quantitatively analyzed. The test results show that compared with the pure power battery module without any thermal management technical measures, the maximum temperature of the thermal management system of the TiO2-CLPHP power battery module under the optimal thermal management strategy is reduced by 10.3℃ and the maximum cooling efficiency is up to 75.00%. In the dynamic test condition, the TiO2-CLPHP power battery module thermal management system implemented the optimal thermal management strategy of thermal efficiency, and the maximum temperature rise of the power battery was 9.7℃, 7.3℃, 7.5℃, and the maximum temperature difference of the battery was not more than 3.5℃ and 2.5℃, respectively. And when optimal thermal management, whose goal is to have a small critical temperature rise strategy by operating energy consumption, is adopted. The maximum temperature rises are 10.5℃, 8.5℃ and 6.9℃, respectively, with the maximum battery temperature difference not exceeding 3.6℃ and 3.5℃. Compared with the thermal management strategy with optimal thermal efficiency, this not only ensures the thermal management efficiency but also reduces the energy consumption index of the system (that is, it has less thermal management energy consumption). In addition, under different ambient temperatures, compared with the optimal thermal management strategy for thermal efficiency, the TiO2-CLPHP power battery module thermal management system implements the optimal thermal management strategy for energy consumption with a smaller temperature rise critical value, and the energy consumption index of the system can be reduced by up to 60.58%. This indicates that for the TiO2-CLPHP power battery module thermal management system, the proposed energy consumption optimal thermal management strategy with a small critical value can effectively take into account both thermal management efficiency and thermal management energy consumption, which is the most ideal thermal management strategy for power battery modules.