Whether the automobile air conditioning system can run normally or not is related to the comfort, economy and safety of the car owners. Air conditioning system is an important device to regulate the temperature and air in automobile. With the development of social economy and science and technology, automobile has become an indispensable part of our life. The ownership of automobile in our country is also increasing, and people's demand for comfort of automobile is also increasing. The comfortable interior environment of automobiles depends mainly on the air conditioning technology of automobiles. The development of automobile air conditioning technology is an important key to improve the comfort of automobiles. The automobile technology is developing continuously, and the automobile air conditioning technology is also developing continuously.

1. Structure of Automotive Air Conditioning System

Air conditioning and refrigeration systems in automobiles are generally driven by compressors, which can be divided into two types: independent and independent automobile air conditioning systems. Independent automobile air conditioning system, whose compressor is driven by a special sub-engine, will not be affected by the main engine. Independent automotive air conditioning system, whose compressor is driven by the drive belt of the main engine, will cause a certain degree of consumption of the power of the main engine in the working process, and the amount produced in the refrigeration process has a relationship with the change of the speed of the automobile, so it is a kind of variable refrigeration. System. Whether independent or non-independent, the air conditioning system of all automobiles includes expansion valve, compressor, evaporator, electrical control, liquid storage and condenser.

2. Working Principle of Automotive Air Conditioning System

Generally, the air conditioning system in automobiles has four aspects in normal work: the first is to compress. First, compressors need to inhale low-pressure and low-temperature refrigerant gases at the outlet of the evaporator, compress those gases into high-pressure and high-temperature gases, and then discharge them from the compressor. The second is the exothermic process after condensation. The high-pressure and high-temperature superheated refrigerant gas passes through the condenser, which reduces the temperature and pressure of the gas. When the temperature of the gas in the condenser reaches about 45 C, the original gas state of the refrigerant will change into liquid state, and a lot of heat will be released at the same time. The third is the expansion process of throttling. After the refrigerant with relatively high pressure and temperature is introduced into the expansion valve device, the volume will gradually increase, while the temperature and pressure will rapidly decrease, and then be removed from the expansion device in the form of fog. Fourth, the endothermic process of evaporation. The misty gas will be directly introduced into the evaporator from the expansion device. At this time, the boiling point of the refrigerant is much lower than the temperature in the evaporator. Therefore, the refrigerant will evaporate into gas. Then, when evaporating, a large amount of heat is absorbed from the surrounding area, and the temperature and pressure are lowered again, and then it is put into the compressor.