Heating generation model and heat dissipation performance of the power battery in electric vehicle

The thermal coupling models were established on the positive plate collector, the negative plate collector and the battery plate, which based on the Bernardi heat generation rate model of a single battery. The heat transfer model of battery group was founded as well. In the natural ventilation environment, the heat generation characteristics of a single battery LiFePO₄ was simulated by using Fluent software. The performances of heat generation and dissipation of battery group were simulated under the condition of forced air convection cooling. The effect of air-outlet position on battery temperature was analyzed. The effect on battery temperature was analyzed based on air-outlet position. In different discharge ratio, the battery temperature was calculated. The calculated results show that the pole ear temperature is higher than polar balde, and the postive ear temperature is greater than negative ear at the end of constant current discharging; The thermal performance of battery could meet the demands of the safe operating temperature in forced cooling conditions; The air-outlet position directly affests the air velocity profile and battery temperature field; The below air-outlet contributes to improve the consistency in thermal state. The error in calculating and testing result is less than 5% at the feature points, which could meet the needs in engineering.