The structure of a central air-conditioning system is shown in Figure 5-1. According to its working principle, it can be divided into four parts: refrigeration unit, cooling water tower, external heat exchange system and cooling fan. The functions of each part are as follows:
Figure 5-1 Structure of a central air-conditioning system
1. chiller pump 2. fan coil 3. expansion tank 4. cooling water tower 5. cooling pump 6. condenser 7. evaporator
(1) chiller unit
used to dehumidify the circulating water going to each room by heat exchange inside the unit to become "chilled water".
(2) Cooling water tower
Used to receive water with heat from cooling pumps, which is cooled to provide cooling water for the chilled water unit.
(3) External heat exchange system
The external heat exchange system consists of chilled water circulation system and cooling water circulation system. Among them, the function of the chilled water circulation system is to send the chilled water out of the chiller unit through the chiller pump into the chilled pipeline, and carry out heat exchange in each room, so that the temperature in the room will drop; the function of the cooling water circulation system is to send the cooling water through the heat exchange by the cooling pump into the water tower, and then send it back to the chiller unit by cooling the humidity and cooling the water tower, and then send it back to the chiller unit, and then continuously circulate to take away the heat released in the chiller unit. The heat released in the freezing unit is taken away.
(4) cooling fan
Cooling fan indoor fan and cooling tower fan two kinds: indoor fan installed in the room need to cool down, used by the chilled water cooled by the cold air blown into the room, accelerate the flow of air in the room, so that the room to cool down faster and more uniform temperature; Cooling tower fan is used to enter the cooling tower of the cooling water to cool through the fan to generate the wind speed, the heat will be emitted. Wind flow rate, the heat will be emitted to the atmosphere, so that the water temperature into the tower is rapidly reduced.