At present, there are two main heating systems for new energy vehicles: electric heating and oil heating.
Regarding the application of heat pump technology, although it has been widely used in some fields such as air source heat pumps, there are still some problems in the application of heat pump technology in the field of automotive air conditioning.
The principle of a heat pump is to use a reverse Carnot cycle, utilizing the closed-loop circulation of refrigerant, to release the heat energy absorbed by the outdoor unit through the indoor unit, achieving the transportation from low temperature to high temperature. This technology is widely used in winter heating of cold and warm air conditioning. However, the heating of finished air conditioners requires the addition of electric auxiliary heating, as the low evaporation temperature of outdoor units at low temperatures can easily cause frost on the surface of the evaporator, affecting the heating effect.
At a temperature of 5 ℃, the operation of the heat pump is not stable enough, and the problem of frosting is difficult to solve. Even below 0 ℃, the fins of the outdoor unit are frosted and burnt, reducing the heating capacity. Therefore, the efficiency of heat pump technology performs poorly in high cold and high humidity environments. Although the thermal efficiency (COP) can reach 300%, in practical use, the efficiency will significantly decrease due to low temperatures. Therefore, heat pump air conditioning has not yet been widely used in the automotive industry.