Hanbell screw compressor oil replacement operation specification

Maintenance and operation instructions for the refrigerating oil of the screw refrigerant compressor of Hanbell

1. The role of lubricating oil:

   1) A dynamic seal is formed between the screw and the compression chamber and the male and female screws to reduce the leakage of refrigerant from the high pressure side to the low pressure side during the compression process.  

2) Cool the compressed refrigerant, the oil is injected into the compressor, absorb the heat generated by the refrigerant gas in the compression process, and reduce the exhaust temperature.  

3) An oil film is formed between the bearing and the screw to support the rotor and provide lubrication.  

4) Transmit the pressure difference force, drive the capacity adjustment system, adjust the position of the capacity adjustment slider through the action of the compressor's loading and unloading solenoid valve, and realize the compressor capacity adjustment control.  

5) Reduce running noise  

Note: The lubricating oil inside the compressor is the key to maintaining the normal operation of the compressor. Common lubricating oil problems include:  

  1) The mixing of foreign matter can cause lubricating oil pollution and block the oil filter.  

2) The effect of high temperature causes lubricant deterioration and loss of lubricating function. 

  3) System water pollution, acidification and erosion of motors.  

2. Compressor refrigerating oil detection and replacement:   

For system manufacturers, the inspection and replacement cycle of compressor refrigerating oil is related to the process control of its production process. If the cleanliness of the evaporator and condenser of the system and the system pipeline are better controlled, relatively speaking, less pollutants enter the compressor, and the inspection and maintenance cycle can be relatively longer.  

One. Main monitoring indicators:   

1) PH value index:   

The acidification of the lubricating oil will directly affect the life of the compressor motor, so the acidity of the lubricating oil should be checked regularly. Generally, the acidity of lubricating oil is lower than PH6 and must be replaced. If the acidity cannot be checked, the filter drier of the system should be replaced regularly to keep the dryness of the system in a normal state. 

  2) Pollution degree index: If the pollutants in 100ml of refrigerating oil exceed 5mg, it is recommended to replace the refrigerating oil. 

  3) Water content: more than 100ppm, the refrigerating oil needs to be replaced.  

two. Replacement cycle:   

Generally, the lubricating oil must be checked or replaced every 10,000 hours of operation. After the first operation, it is recommended to replace the lubricating oil and clean the oil filter every 2500 hours. Residues due to system assembly will accumulate in the compressor after the official operation. Therefore, the lubricating oil should be changed every 2500 hours (or 3 months), and then periodically according to the cleanliness of the system. If the cleanliness of the system is good, it can be replaced every 10,000 hours (or every year). 

  If the compressor discharge temperature is maintained at a high temperature for a long time, the deterioration of the lubricating oil will progress quickly, and the chemical properties of the lubricating oil must be checked regularly (every 2 months), and replaced if it fails. If it is not possible to check regularly, you can follow the recommendations below.  

    Operating exhaust temperature (℃) 





Above 105℃  

Replacement time (hours)  






   Replacement time (number of months of operation)  






Note: The operating period is calculated based on 16 hours of operation per day      

3. Refrigerating oil replacement operation method:   

One. Replace the refrigerating oil without internal cleaning:   

The compressor performs a pumping action to recover the system refrigerant to the condenser side (note that the minimum suction pressure of the pumping action is not less than 0.5Kg/cm2G), remove the refrigerant in the compressor, and retain a little internal pressure as the power source. The refrigerant oil is discharged from the oil drain valve of the compressor. The position of the compressor oil drain angle valve is shown in the figure (1) below. After the freezing oil is drained, you can use this   

 ※Note: The installation position of the flange (cover) of the cleaning hole is the same as that of the oil level switch flange (cover), and the oil level switch flange is an optional component. ※          Oil level switch flange (cover)  

Clean hole flange (cover)  

Drain angle valve  

Oil filter  


   Diagram (1)  

Low pressure side angle valve  

Oil filter connector  

High pressure side angle valve  

Diagram (two)  

The angle valve is closed. At this time, the suction force of the vacuum pump can be used to draw new refrigerating oil from the drain valve into the compressor through the conduit. After reaching the standard oil volume, the drain valve is closed and the vacuum is continued to the standard requirements. Oil change operation. This can prevent the system from leaking air and causing difficulties in subsequent operations. The contact point of the vacuum pump is recommended to choose a high (low) pressure side angle valve (as shown in Diagram 2) or other relatively high points to prevent the pumping of refrigerant oil from damaging the vacuum pump.  

two. Change the refrigerating oil and clean the inside:   

The action of draining the oil is as mentioned above. After the refrigerating oil is drained and the pressure inside and outside the compressor is balanced, loosen the flange bolts with an Allen wrench, and remove the oil filter joint and the clear hole flange (or oil level switch flange) After that, remove the contaminants in the compressor oil tank, and check whether the oil filter mesh is damaged, and blow off the oil sludge, contaminants, etc., or replace the new oil filter, pay attention to when replacing it. The filter interface nut should be tightened to make a good seal to prevent internal leakage; the inner gasket of the oil filter joint must be replaced to prevent internal leakage; other flange gaskets are also recommended to be updated.      

4. Precautions:

1. Different brands of refrigerating oil must not be mixed, especially mineral oil and synthetic ester oil must not be mixed.  

2. If you change a different brand of refrigerating oil, be careful to remove the original refrigerating oil remaining in the system.  

3. Some oils have hygroscopic properties, so do not expose the refrigerated oil to the air for a long time. During installation, shorten the exposure time as much as possible, and do a good job of vacuuming.  

4. If the system has experienced a compressor motor burnout failure, pay special attention to removing the acidic substances remaining in the system when replacing the new machine, and check the acidity of the refrigerating oil after 72 hours of commissioning operation. It is recommended to replace the refrigerating oil and the dry filter to reduce The possibility of acid etching. After running for a month or so, check again or change the refrigerating oil.  

5. If there has been a water ingress accident in the system, special attention should be paid to removing the water. In addition to replacing the refrigerating oil, special attention should be paid to detecting the acidity of the oil, and replacing the new oil and the filter drier in time.