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

Automobile air conditioners are generally composed of compressors, electrically controlled clutches, condensers, evaporators, expansion valves, liquid storage dryers, pipelines, condensing fans, vacuum solenoid valves, idlers and control systems. The automobile air conditioner is divided into high pressure pipeline and low pressure pipeline. High pressure side includes compressor output side, high pressure pipeline, condenser, liquid storage dryer and liquid pipeline; The low pressure side includes evaporator, accumulator, return line, compressor input side and compressor oil pool.

Liquid receiver dryer 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, which replenishes the refrigerant for the extra space for leaking refrigerant. On the other hand, like the air filter, it filters out impurities in the refrigerant. A certain amount of silica gel material is also installed in the liquid storage dryer to absorb water.

Condenser and evaporator - although they are called differently, they are similar in structure. They are all devices that are filled with metal sheets for heat dissipation on a row of curved pipes to realize the heat exchange between the outside air and the materials in the pipes. Condensation of the condenser refers to the condensation of refrigerant in the pipe from gas to liquid. Its principle is similar to the radiator tank of the engine (the difference is only that the water in the tank is always liquid), so it is often installed in the front of the car to enjoy the cool wind from the front together with the tank. In a word, where the condenser is cool, it can be cooled and condensed. The evaporator is the opposite of the condenser. It is the place where the refrigerant changes from a liquid state to a gaseous state (i.e. evaporation) to absorb heat.