10.11.6 The principle of the air conditioning system
Thus, in case if you are hot, on the control panel inside the passenger compartment you can press the appropriate button. At that time the clutch connects the pulley to the compressor shaft - and the air conditioner will start. The compressor compresses gaseous freon (refrigerant), which is why it is very hot, and pumps it through a pipeline into a condenser, where the compressed freon is cooled. Additional electric fan facilitates its operation. Upon cooling, the compressed freon condenses and flows out of the condenser already in a liquid form. After that, the liquid freon flows through the receiver-dryer. Here the refrigerant is filtered from the wear products of the compressor and water.
Note
Receiver-dryer has one more important function – it is damping the pulsations of refrigerant.
After cleaning and equalizing the pressure, the freon flows towards the passenger compartment, where the expansion valve is located. While passing through the expansion valve and getting into the evaporator, the freon turns into a gaseous state (boils), while strongly cooling. Cold freon cools the evaporator, and the fan blows the cold air from the evaporator into the passenger compartment. After passing through the evaporator, the still cold enough freon enters the compressor again. The circle is now closed.
Note
The part of the hoses that are situated between the compressor and the expansion valve is called the pressure head, or high pressure line. It can always be identified by hot thin metal tubes. The part from the evaporator to the compressor is called the return line, or the low pressure line. It consists of thick tubes and is cold to the touch. In case if during operation of the compressor pressure inside the pressure line fluctuates from 7 to 15 atm (in emergency cases even up to 30), the pressure inside the return line does not exceed 1-2 atm. When the air conditioner is turned off, the pressure in both lines is equalized and is about 5 atm.
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