How to maintain the chiller in winter?

In summer, many factories run chillers 24 hours a day, which is very efficient. But in winter, many factories in some areas do not need chillers for cooling. When the chiller is shut down, the chiller must be maintained. If the life of the chiller can be extended by many years, how to maintain the chiller in winter?
Ⅰ Clean
1. Turn off the water source of the chiller, and clean the unit components and the water in the pipes to prevent the unit components from being corroded by water or the temperature is too low to frost the copper pipe after the shutdown.
At the same time, unscrew the drain nut under the water pump to drain the remaining water in the water pump to prevent the water system from freezing due to the low ambient temperature, causing the evaporator to burst and crack. It may cause refrigerant leakage or damage to the impeller of the pump.
2. Clean the fan of the air-cooled chiller and keep it clean, which can be blown with an air gun.
3. Whether there are impurities in the evaporator water tank, and clean it.
4. Check the use of lubricating oil through data records, and change lubricating oil regularly according to standards to maintain good lubrication.
5. The cooling water pipe of the water chiller must be insulated, not only to prevent serious loss of cooling capacity, but also to prevent condensation on the outside of the pipe.
Ⅱ Maintenance
1. Keep the refrigerant and oil clean and free of moisture to avoid moisture pollution. After any part of the cooling system is repaired, it is necessary to vacuum to remove moisture before restarting work.
2. Keep the inlet filter of the chiller clean. Regular inspections are required, especially the suction channel of the compressor may have welding slag and pipeline corrosion. Too much dirt on the suction filter will cause the filter to rupture and particles will leak into the compressor.
3. Keep the oil filter clean. If the pressure drop increases, it means that there is dirt, and you need to stop the machine to clean or replace the oil filter. Long-term operation of the compressor under high pressure drop will cause oil consumption and early damage to the compressor oil and bearings.
4. Avoid blockage of the freezer compressor by liquid refrigerant. Ensure that there is sufficient overheating and a suitable suction accumulator to avoid injecting liquid refrigerant into the compressor. Liquid refrigerant will shorten the life of the compressor, and under extreme conditions will cause the compressor to be completely damaged.
5. Long-term shutdown to protect the compressor. When shutting down without stopping for a long time, the compressor should be evacuated to low pressure, and then filled with nitrogen or oil.
6. As long as the compressor has obvious vibration level, noise or performance changes at any time, preventive maintenance inspections should be carried out.