Refrigerating system and oil return control method and device thereof

Abstract

The invention discloses a refrigerating system and an oil return control method and device thereof. The oil return control method comprises the following steps that the oil level of an oil storage device is acquired; whether the oil level is smaller than a preset oil level or not and whether the state lasts for a first preset time or not are judged; if the oil level is smaller than the preset oillevel and the state lasts for the first preset time, the current energy adjustment state of the refrigerating system is acquired; and oil return energy adjustment control is carried out over the refrigerating system according to the current energy adjustment state. According to the oil return control method, it can be guaranteed that oil return can be achieved on the system well under the severe condition, and the problem of system oil leaking caused by long-time severe loaded operation is avoided.

Description

technical field [0001] The invention relates to the technical field of refrigeration systems, in particular to an oil return control method for a refrigeration system, an oil return control device for a refrigeration system, and a refrigeration system. Background technique [0002] For variable frequency screw and variable frequency centrifugal units, the lubricating oil that lubricates the mechanical moving parts of the compressor will inevitably be mixed into the refrigerant circulation system along with the seal leakage. The conventional oil return control method is to inject excess lubricating oil in the refrigerant back to the system oil tank or compressor oil pool through the ejector. [0003] However, when the system can be adjusted low, there will be insufficient refrigerant flow, so that part of the lubricating oil adheres to the low-pressure heat exchange pipeline and cannot be brought back to the system oil tank or compressor oil pool; when the system can be adjus...

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Problems solved by technology

[0003] However, when the system can be adjusted lower, there will be insufficient refrigerant flow, so that part of the lubricating oil adheres to the low-pressure heat exchange pipeline and cannot be brought back to the system oil tank or compressor oil pool; when the system can be adjusted higher , the lubricating oil in the refrigerant circulation system will increase with the increase of the refrigerant discharge rate, so that the oil return volume of the oil return system of the whole machine is less than the oil discharge volume

Running under the above two harsh working conditions for a long time will cause oil leakage over time

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