The chiller refrigeration system consists of four basic parts: compressor, condenser, throttle, and evaporator. The four major parts are connected in a certain order by copper pipes to form a closed system, and a certain amount of refrigerant is filled in the system.

The compressor sucks in low-temperature and low-pressure Freon gas from the evaporator and compresses it into high-temperature and high-pressure Freon gas. Then it flows through the thermal expansion valve and is throttled into a low-temperature and low-pressure Freon liquid two-phase object. Then the low-temperature and low-pressure Freon liquid absorbs heat from the indoor air in the evaporator, such as compression, condensation, throttling, evaporation, and repeated cycles.

1. Chiller

This is the "cooling source" of the central air conditioner. The circulating water leading to each room is "internally exchanged" by the chiller and cooled down into "cooling water".

2. External heat exchange system

It is composed of freezing pump and chilled water pipeline. The chilled water flowing out from the chiller is pressurized by the refrigeration pump and sent to the chilled water pipeline, where heat exchange occurs in each room, taking away the room's heat and causing the room's temperature to drop.

The cooling water circulation system consists of cooling pumps, water pipes, and towers. The chiller performs heat exchange and releases a large amount of heat while cooling the water temperature. This heat is absorbed by the cooling water, causing the temperature of the cooling water to rise. The cooling pump presses the heated cooling water into the cooling tower, allowing it to exchange heat with the atmosphere in the cooling tower, and then the cooled cooling water is returned to the chiller.

3. Indoor cooling fan

Installed in a room that needs to be cooled, it is used to blow air cooled by chilled water into the room to accelerate the heat exchange.

4. Start-up and operation of chiller

Check each compressor's oil level and temperature: the oil level is between 1/3 and 2/3; the oil temperature must be between 50℃ and 60℃, and the heater must be hot to touch. Check the main power supply voltage and current: the power supply voltage is within the range of 340V ~ 440V; the three-phase voltage unbalance value is

Start the chilled and cooling water pump: After the circulation of the two water systems is established, adjust the opening of the inlet and outlet valves of the evaporator and condenser.

Check the chilled water supply temperature to determine the appropriate set value. If not, it can be changed.

Pre-start checks:

1. Check the tightness of the electrical connectors (main circuit, control circuit), and heat the oil tank for at least 24 hours so that the temperature of the oil tank cannot be lower than 38 degrees.

2. Check the status of each unit's valve, water pump, pressure gauge, thermometer, filter, etc..

3. Check the condition of the end of the unit.

4. Check the condition of the cooling tower.

5. Turn on the chilled water pump and cooling water pump of the water system separately to check whether the water system is operating normally to ensure that no gas is entrained and that the pressure drop of the inlet and outlet water of the water system is within the required range.

5. Monitoring and adjustment of chiller operation

For chillers, the following conditions should be paid attention to during operation:

1. The temperature and pressure of the evaporator chilled water inlet and outlet.

2. The temperature and pressure of the condenser cooling water inlet and outlet.

3. The pressure and temperature of the refrigerant in the evaporator.

4. The pressure and temperature of the refrigerant in the condenser.

5. Current and voltage of the main motor.

6. Lubricating oil pressure and temperature.

7. Is the compressor unit running smoothly, and are there any abnormal noises?

8. Are there any leaks in the valves of the unit?

9. Whether the joints with each water pipe are tight.