The air heating system in the passenger compartment is not capable of providing the required temperature regime. At ambient temperatures exceeding 23°C, it must be cooled to create comfortable conditions for the driver and passengers. Air conditioning systems are used to solve this problem. The air conditioning system scheme is shown in the picture:
Picture: Air conditioning system in the car:
1 – Compressor; 2 – electrical clutch; 3 – capacitor; 4 – auxiliary fan; 5.7 – pressure sensor; 6 – receiver-dryer; 8 – temperature switch; 9 – thermal sensor; 10 – condensate tray; 11 – evaporator; 12 – evaporator fan; 13 – fan switch; 14 – pressure reducing valve
The system is filled with refrigerant, which, depending on temperature and pressure, can change from gaseous to liquid and vice versa. The refrigerant is the gas used to fill the system. Until recently, R12 freon was the refrigerant for car air conditioners. After the publication of the theory of the destruction of the ozone layer of the earth’s atmosphere by refrigerant fluorocarbons contained in the refrigerant R12, its use was reduced.
Modern air conditioning systems use R134a freon (tetrafluoroethane), which is considered “environmentally friendly”. This refrigerant belongs to the class of hydrofluorocarbons (HFC), does not contain chlorine and is not very harmful, but its efficiency is 10-15% lower than R12, and it is more fluid. However, car air conditioners using R134a require a higher operating pressure to operate effectively. The use of the refrigerant R134a has led to the complication of air conditioning systems. It should be noted that the new and old refrigerants are incompatible, since the compressor oils charged with them are incompatible.