Introduce these three parts of central air conditioning, the more detailed the better (the picture can be enlarged)

These drawings are divided into two types: external machines and internal machines. The one on the left is the external machine, and the one on the right is the internal machine.

External machine: including compressor, condenser, capillary (or expansion valve), gas-liquid separator and filter. There is also a high-voltage 220v or 380V distribution system, as well as control circuits, temperature and pressure sensors.

The compressor compresses the refrigerant gas and does work on it, which increases the internal energy and pressure of the refrigerant. Generally 70- 100, pressure 15bar-20bar.

The condenser cools the refrigerant gas with high temperature and high pressure, and the cooling medium is outdoor air. At this time, the pressure and temperature of the refrigerant gas will be reduced, and most of the refrigerant will be liquefied.

Cut-off mechanism of capillary expansion valve: The liquid refrigerant passes through the cut-off mechanism to the back end, and the process pressure suddenly drops. Under this pressure, the boiling point of the refrigerant liquid is lower than the refrigerant temperature at this time, and the refrigerant begins to evaporate, which needs to absorb a lot of heat. This evaporation process takes place inside the machine.

Dryer: Absorbs the water in the system. If there is water in the system, the harm is very great. You can know the harm according to my answer to this question/question/182413331.html.

Gas-liquid separator: installed on the pipeline of refrigerant returning to compressor. The refrigerant liquid stone that has not completely evaporated in the internal machine cannot enter the compressor and the liquid cannot be compressed. If it enters, the compressor will be very dangerous. So this device is set to prevent liquid from entering the compressor, and the refrigerant entering the compressor from here also has the function of cooling the compressor. Note that the pressure here is about 4-5bar, while the pressure at the compressor outlet is above 15bar, and this pressure difference is the driving force of copper refrigerant circulation.

Internal machine: it can also be called fan coil unit. It is mainly composed of fan (generally centrifugal fan) and coil. The coil is a copper tube or aluminum tube with many fins (copper or aluminum). The refrigerant liquid flows in the tube, and the air outside the tube exchanges heat with the refrigerant through the fins, and the power is given by the fan. At the same time, there is a water receiving tray just below the coil of the internal machine, which is used to collect the condensed water and discharge it outdoors.

Square indoor unit is a ceiling fan coil unit, which is suitable for rooms with ceilings.

The rectangular indoor unit is a side-blown fan coil unit, which is suitable for rooms without ceiling. Generally, it is directly above the entrance of the room, with air intake at the lower part and cold air at the side.

These two things are no longer called parts. It can be called refrigeration (heating) unit and fan coil unit.