Screw chiller is widely used in many industries such as rubber and plastic, equipment cooling, chemical reaction, high frequency heating, paper making and food.When we start the screw chiller, we should pay attention to the need to operate the chiller with the correct steps:
1. Confirm whether the state of each valve in the screw chiller meets the boot requirements.
2. Supply power to the electrical control device of the unit, and turn on the power switch to make the power control indicator light on.
3. Start the cooling water pump, cooling tower fan (if it is an air-cooled screw chiller, please turn on the fan) and refrigerated circulating water pump, and you should see the operation indicator light of the three.
4. Check whether the lubricating oil temperature reaches 30℃. If it is less than 30℃, the electric heater should be opened for heating, and the oil pump can be started at the same time, so that the temperature of the lubricating oil cycle is evenly increased.
5. After the oil pump starts running, put the energy regulation control valve in the load reduction position and confirm that the slide valve is in the zero position.
6. Adjust the oil pressure regulating valve. Make the oil pressure reach 0.5 ~ 0.6MPa.
7. Turn on the power supply of the compressor, start the control switch, and open the suction valve of the compressor. After a delay, the compressor starts to run.
8. Close the solenoid valve control circuit in the liquid supply pipeline and start the solenoid valve. Liquid refrigerant is supplied to the evaporator, the energy regulator is placed in the loading position, and the load is increased step by step over time. At the same time, observe the suction pressure, and adjust the expansion valve to stabilize the suction pressure between 0.36 MPa and 0.56MPa.
9. After the compressor runs, when the lubricating oil temperature reaches 45℃, disconnect the power supply of the electric heater, and open the inlet and outlet valves of the cooling water of the oil cooler at the same time, so that the oil temperature can be controlled within the range of 40 ~ 55℃ during the operation of the compressor.
10. If the cooling water temperature is low, the fan of the cooling tower can be closed temporarily.
11. Open the fuel injection valve 1/2 to 1 turn, and make the suction bar and the unit's outlet valve in fully open position.
12. Adjust the energy regulator to 100% position, and adjust the expansion valve to keep the suction superheat above 6℃
Inspection of screw chiller during start-up operation. After the unit is started and put into operation, attention should be paid to the following inspection to ensure the safe operation of the unit.
(1) Whether the sound and vibration of the compressor are normal during operation.
The exhaust pressure of the compressor is below 1.55mpa, and the exhaust temperature is below 100℃.
③ When the compressor is in full load operation, whether the suction pressure value is in the range of 0.36 ~ 0.56mpa.
The oil temperature of lubricating oil is below 60℃, the oil pressure is higher than the exhaust pressure 0.15 ~ O.3MPa, and the oil level is normal.
⑤ The sound and vibration of the refrigerant water pump, cooling water pump, cooling tower fan during operation, the outlet pressure of the pump, water temperature and other indicators are within the range of normal working parameters.
⑥ Screw chiller compressor operation process, the motor running current is within the specified range. If the current is too large, it should be adjusted to load reduction operation, to prevent the motor from burning due to the running current is too large.
If abnormal conditions are found, it should be immediately shut down, find out the cause, troubleshooting, and then restart the unit. Must not take the screw chiller with the problem to run, so as not to cause a major accident.