Heat Pump Air Conditioner For Electric Vehicles
It is well known that winter range is one of the biggest pain points of electric vehicles. Data shows that PTC (thermistor) heating commonly used in electric vehicles can reduce the winter cruising range of electric vehicles by about half. To solve this problem, automotive engineers invented a black technology for electric vehicles - heat pump air conditioning. Facts have proved that heat pump air conditioning is an effective solution to solve the winter cruising range of electric vehicles! Tests have shown that using a heat pump air conditioner for heating in winter can reduce energy consumption by up to 60% compared to using PTC heating, and increase the cruising range in winter by up to about 25%!
What is a heat pump air conditioner? What is the difference between heat pump air conditioners and traditional fuel vehicle air conditioners?
The basic principle of refrigeration of traditional fuel vehicle air conditioners is to use a compressor to convert low-pressure gas refrigerant into high-pressure gas refrigerant. After releasing heat through the condenser, it becomes high-pressure liquid refrigerant, and then passes through the expansion valve and becomes low-pressure liquid refrigerant. The heat absorbed in the evaporator turns into low-pressure gaseous refrigerant and returns to the compressor, and the local low temperature caused by the heat absorbed by the evaporator blows cold air into the passenger compartment through the blower. A simple summary is one sentence, using the principle of evaporation and heat absorption to create local low temperature areas and blow them into the passenger compartment. The basic principle of heating is more simple and crude. The engine coolant is introduced into the air-conditioning heater core, and then the hot air is blown into the passenger compartment through the blower.
In fact, heat pumps are not a new thing. Products with similar principles have very mature applications in the home market. The typical representative is the air-source water heater that has emerged in recent years. The four words "energy saving and environmental protection" are always prominently written on the promotional slogans. Its energy saving The principle is to use a small amount of electrical energy to obtain a large amount of thermal energy from the air.
Since the heat pump system is in the heating mode, the outside heat exchanger is used as an evaporator and needs to absorb heat from the outside environment. When the outside temperature is low, or when the temperature of the outside heat exchanger is close to the outside ambient temperature, the outside heat exchanger is used as an evaporator. The heat exchanger cannot effectively absorb heat from the external environment, causing the system to be unable to continue operating. In addition, when the temperature outside the car is low, if the air contains a lot of moisture, the moisture in the air will frost on the surface of the outside heat exchanger, and the frosted outside heat exchanger can no longer benefit from the external environment. The ground absorbs heat, causing the heat pump air conditioner to be unable to continue to provide heating function. Therefore, general heat pump systems cannot work properly below -10°C. Therefore, the mainstream technical solution of car companies is still to use heat pumps and PTC heating together. When the ambient temperature is too low and the heat pump cannot work, PTC is started as a backup heat source. However, with the continuous breakthroughs in low-temperature heat pump technology below -20°C, PTC heating It is an inevitable trend that air conditioners will be gradually replaced by heat pump air conditioners!
