What are the effects of poor oil return of the screw chiller?

The screw chiller has poor oil return, which will cause a large amount of lubricating oil to stay in the evaporator pipe. When the oil film increases by 0.1mm, it will directly affect the cooling of the system. This will cause the lubricating oil in the system to accumulate more and more, causing a vicious circle, increasing operating costs and reducing operating reliability. Under normal circumstances, it is permissible for the oil and gas mixture to circulate in the system if the refrigerant gas flow rate is less than 1%.