Modern air conditioning system consists of refrigeration system, heating system, ventilation and air purification device and control system.

1. Ventilation system: its function is to ensure indoor ventilation when the car is running, that is, to continuously flush fresh air into the car room and drive out dust, carbon dioxide and harmful gases from the engine. In cold winter, the fresh air should also be heated to ensure that the indoor temperature is appropriate.

2. Heating system: its function is to heat the air inside the car or the fresh air entering the car from the outside to achieve the purpose of heating and dehumidification.

3. Refrigeration system: its function is to reduce the temperature inside the vehicle when the ambient temperature outside the vehicle is high, so that passengers feel cool and comfortable.

4. Air purification system: its function is to filter the introduced air, constantly remove the dirty gas in the car room, and keep the air in the car clean.

5. Control system: the control system is mainly composed of electrical components, vacuum pipelines and operating mechanisms. On the one hand, it is used to control the temperature and pressure of the refrigeration and heating system, on the other hand, it is used to control the temperature, air volume and flow direction of the air in the car room, so as to improve the functions of the air conditioning system.

Automotive air conditioners are generally composed of compressors, electronic clutches, condensers, evaporators, expansionvalves, receiverdriers, pipes, condensing fans, vacuumsolenoid valves, idlers and control systems. Automotive air conditioning is divided into high-pressure pipeline and low-pressure pipeline. The high-pressure side includes the compressor output side, high-pressure pipeline, condenser, receiver dryer and liquid pipeline; The low-pressure side includes evaporator, accumulator, return pipeline, compressor input side and compressor oil pool.

Receiver drier is actually a device for storing refrigerant and absorbing refrigerant moisture and impurities. On the one hand, it is equivalent to the fuel tank of a car, replenishing refrigerant for the extra space of leaking refrigerant. On the other hand, it is like an air filter, filtering out impurities in the refrigerant. A certain amount of silica gel material is also installed in the receiver dryer to absorb water.

Condenser and evaporator -- although they are called differently, their structures are similar. They are all devices that cover a row of curved pipes with metal sheets for heat dissipation, so as to realize the heat exchange between the outside air and the substances in the pipes. Condensation of the condenser refers to the condensation of the refrigerant in its pipe from the gaseous state to the liquid state. Its principle is similar to that of the cooling water tank of the engine (the difference is that the water in the water tank is always liquid), so it is often installed in the front of the car, together with the water tank, to enjoy the cool wind from the front. In short, where the condenser is cool, so that it can dissipate heat and condense. The evaporator is just the opposite of the condenser. It is the place where the refrigerant changes from liquid state to gaseous state (i.e. evaporation) to absorb heat.