Optimization of battery thermal management system under low temperature conditions
Due to the unsustainability of traditional energy sources and the increasing environmental pollution, governments and automobile manufacturers in various countries have accelerated the transformation to new energy vehicles, focusing on promoting the development of electric vehicles mainly driven by pure electricity. As the market share of electric vehicles continues to increase, power batteries and intelligent control are becoming the technological development trend of electric vehicles. No better solution was found. Different from traditional gasoline vehicles, electric vehicles cannot use waste heat to heat the cabin and battery pack. Therefore, in electric vehicles, all heating activities need to be completed through heating and energy sources. Therefore, how to improve the utilization of the remaining energy of the vehicle becomes an electric A major issue with automotive thermal management systems.
The electric vehicle thermal management system regulates the temperature of each part of the vehicle by managing the heat flow, mainly including the temperature control of the vehicle motor, battery and cockpit. The battery system and the cockpit need to consider two-way adjustment of cold and heat, while the motor system only needs to consider heat dissipation. Most of the early thermal management systems of electric vehicles were air-cooled heat dissipation systems. This type of thermal management system took the temperature adjustment of the cockpit as the main design goal of the system, and rarely considered the temperature control of the motor and battery, wasting the power of the three-electric system during operation. heat generated in. As the power of the motor and battery increases, the air-cooled heat dissipation system can no longer meet the basic thermal management needs of the vehicle, and the thermal management system has entered the era of liquid cooling. The liquid cooling system not only improves the heat dissipation efficiency, but also increases the battery insulation system. By controlling the valve body, the liquid cooling system can not only actively control the direction of heat, but also make full use of the energy inside the vehicle.
The heating of the battery and the cockpit is mainly divided into three heating methods: temperature coefficient (PTC) thermistor heating, electric heating film heating and heat pump heating. Due to the chemical characteristics of the power battery of electric vehicles, there will be problems such as cold car power loss, short cruising range, and reduced charging power under low temperature conditions. In order to ensure that electric vehicles can achieve suitable working conditions under various extreme conditions, To meet the needs of use, the battery thermal management system needs to be improved and optimized for low temperature conditions.
