Analysis and Research of Compound Refrigeration based on Logic Control Battery

Abstract

In order to ensure the safety and stability of the power battery, the design of refrigeration system is very important. Firstly, a battery model based on logic control and lumped heat parameters was established to determine the real-time and accurate state of battery heat generation, heat transfer, radiation heat dissipation and battery temperature. The feasibility of the simulation model is verified by the experimental results. Secondly, the refrigeration system of battery air cooling and liquid cooling is established, and a new composite cooling system is proposed and built. By changing the wind speed and flow rate, the variation of the cooling effect of air cooling and liquid cooling with the medium flow rate was analyzed. The results show that, in a certain range, the larger the flow rate, the more obvious the cooling effect of the cooling method, and the flow rate is positively correlated with the cooling effect. In order to compare the cooling effect of the new composite cooling system, the temperature rise curves, temperature difference curves and energy consumption of different cooling methods were analyzed under the discharge rates of 4C and 8C.he results show that when the system tends to be stable, the total energy consumption of liquid cooling and mixed cooling is almost the same, and the energy consumption of air cooling is the largest. According to the analysis of the maximum equilibrium temperature difference inside the battery unit when the temperature is stable, the temperature difference of the composite cooling method is the smallest, about 1℃. Moreover, by analyzing the fluctuation range of battery pack temperature when it is stable, the fluctuation of composite refrigeration is the smallest, only 2℃. In conclusion, the hybrid refrigeration system based on logic control has good cooling performance.