In this article, I would like to describe the device of the car air conditioner and to draw the attention of readers to the mechanism of its functioning.
Any complex unit used in automotive technology requires constant care, and air conditioning is no exception to this rule. Rather, on the contrary, attention to this expensive part should be proportional to the losses incurred by the owner if, God forbid, something happens with the “konde”. In order to better understand the needs of this unit, let's recall the device of an automobile air conditioner and the principles of its operation.
The air cooling system inside the car works exactly according to the same principle as a regular refrigerator in your kitchen. In a closed, sealed system filled with freon, refrigeration oil is dissolved. The task of the oil is to lubricate the compressor and the entire system.
The device of the air conditioner for each automaker is its own. But fundamentally, these designs are practically no different.
What happens when you press the start button of the cooling system? When you turn on a working air conditioner, the electromagnetic clutch is turned on , and the pressure disk with a characteristic metallic sound is magnetized to the pulley through which the timing belt passes (when the air conditioner is off, the pulley spins idle). The compressor starts to run. Its task is to compress freon, which is now in a gaseous state. In the process of compression, freon is heated, and then liquid and hot freon flows through the tube into a condenser, or, as it is also called, a radiator. This name is quite acceptable, since gas heated up and compressed to a liquid state is cooled precisely in this design.
It helps the fan to give heat better and faster, and in the event that the machine is still moving, an oncoming air stream is additionally connected to the cooling process.
When the cooling cycle is completed, the liquid freon still under pressure at the outlet of the radiator enters the receiver-dryer. Here it is cleaned of dirt and compressor work products before being fed back into the system. Some manufacturers think of an air conditioner device better than others. They add a peephole into the receiver's design, looking into which, you can visually evaluate the filling of the system. Unfortunately, this feature is available on a limited number of machines, and the vast majority of manufacturers do not introduce such a simple and useful option into an air conditioning device.
But we were distracted, it's time to continue moving along with the stream of freon. After cleaning in a dehumidifier, it moves to the car interior, where it performs the work for which it is intended - cooling the car interior. Passing through a thermostatic expansion valve (TRV), which is installed on the end of the tube going to the cabin evaporator, freon in a state of steam at the boiling point leaves the evaporator. If the steam temperature is too high, the expansion valve closes; if it is too low, it opens. Thus, it performs the function of a thermostatic throttle, changing the cross section of the tube outlet to such values that the temperature of freon at the outlet of the evaporator will be optimal. In the process of evaporation, turning into a gaseous state, the working fluid is very cooled and reaches sub-zero temperatures, this cold is blown off from the evaporator by the interior fan. Then, passing through the evaporator, cold freon enters the compressor, and the cycle starts again.
The part of the system that goes from the compressor to the expansion valve is the pressure line. The tubes there are thin and hot during the operation of the air conditioner. The return line runs from the evaporator to the compressor; its tubes are usually thicker and cooler to the touch. During operation, the pressure in the pressure line is up to 15 atmospheres. In the reverse - 1-2 atmospheres. In a state of rest, it is balanced and amounts to 5 atmospheres both there and there.
I hope that you carefully read this material, and the air conditioning device has become much clearer for you.