Heat Pump Technology Application
In actual use, electric vehicles have a high demand for heating energy consumption in winter. From a thermodynamic point of view, the COP of PTC heating is always less than 1, which makes the power consumption of PTC heating high and the energy utilization rate is low, which seriously restricts electric vehicles. mileage. The heat pump technology uses the vapor compression cycle to utilize low-grade heat in the environment, and the theoretical COP during heating is greater than 1. Therefore, using a heat pump system instead of PTC can increase the cruising range of electric vehicles under heating conditions. With the further improvement of the capacity and power of the power battery, the thermal load during the operation of the power battery is also gradually increasing.
The traditional air cooling structure cannot meet the temperature control requirements of the power battery. Therefore, liquid cooling has become the main method of battery temperature control. Moreover, since the comfortable temperature required by the human body is similar to the temperature at which the power battery works normally, the cooling requirements of the passenger compartment and the power battery can be met by connecting heat exchangers in parallel in the passenger compartment heat pump system. The heat of the power battery is indirectly taken away by the heat exchanger and the secondary cooling, and the integration degree of the thermal management system of the electric vehicle has been improved. Although the degree of integration has been improved, the thermal management system at this stage only simply integrates the cooling of the battery and the passenger compartment, and the waste heat of the battery and motor has not been effectively utilized.
