Power battery heat management system and method for electric vehicle

Abstract

The invention discloses a power battery heat management system and method for an electric vehicle, and belongs to the technical field of power battery heat management. When the temperature of a powerbattery is higher than a first threshold value, a first cooling circuit is connected, a cold medium gets to a condenser and then gets to a refrigeration exchanger through a compressor to conduct heatexchange with refrigerant, so that the cooled refrigerant enters the power battery for heat exchange, and it is achieved that the power battery is cooled in a high-temperature environment; when the temperature of the power battery is higher than a second threshold value and lower than the first threshold value, a second cooling circuit is connected, the refrigerant enters the power battery for heat exchange after being cooled by a cooler, and it is achieved that the power battery is subjected to liquid cooling at a general environment temperature; when the temperature of the power battery is lower than a third threshold value, a heating membrane is started, the power battery is heated up through heating of the heating membrane, and it is achieved that the power battery is heated in a low-temperature environment.

Description

technical field [0001] The invention relates to the technical field of thermal management of power batteries, in particular to a thermal management system and method for a power battery of an electric vehicle. Background technique [0002] With the acceleration of social and economic development, the demand for energy is increasing, and the application of new energy technologies in various fields is getting louder and louder. Currently in the automotive industry, technicians have developed electric vehicles powered by electricity. Among them, as the energy storage device and power source of electric vehicles, the power battery is a key component of electric vehicles, and its performance directly affects the performance of electric vehicles, such as power, driving range, driving performance, safety, etc. The electrochemical reaction and internal resistance in the power battery are very sensitive to temperature changes, which can easily affect the capacity, mileage, service l...

AI Technical Summary

Problems solved by technology

[0005] On the one hand, the convective heat transfer coefficient between the air and the surface of the power battery is low, while the heat conduction path inside the power battery is long, the thermal resistance is large, and the heat dissipation effect is poor, and the front end of the power battery can preferentially contact the low-temperature air, so its cooling effect Obviously, the cooling effect of the rear end is poor due to the small amount of low-temperature air or the high temperature of the air, which causes a large temperature difference inside the power battery, especially when the power battery is discharged at high power. Accumulated, the temperature difference gradually increases, which will easily lead to thermal runaway of the power battery and seriously affect the service life of the power battery;

Images