Oil separator and refrigeration cycle apparatus

Patent metadata

Field	Value
Publication number	US-11460227-B2
Application number	US-201716763123-A
Country	US
Kind code	B2
Filing date	Nov 15, 2017
Priority date	Nov 15, 2017
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

An oil separator has a filter portion in a differential pressure generation mechanism configured to collect, by a differential pressure, lubricating oil that is in a form of mist included in high-pressure refrigerant that flows in a first pipe that is connected to a discharge port of a compressor and allows the collected lubricating oil to move downstream along an internal wall of the first pipe.

First claim

The invention claimed is:

1. An oil separator, comprising:
a first pipe connected to a discharge port of a compressor;
a second pipe connected to a suction port of the compressor;
a differential pressure generation mechanism that has
a third pipe that connects the first pipe and the second pipe with each other and
a filter portion located at a distal end of the third pipe at which the third pipe is connected to the first pipe,
the differential pressure generation mechanism being configured to generate a differential pressure between a pressure of high-pressure refrigerant that flows in the first pipe and a pressure of low-pressure refrigerant that flows in the second pipe; and

an oil return mechanism that has
an oil return port opened and formed at the first pipe and disposed downstream of a connection position at which the third pipe is connected to the first pipe and
a portion of an oil return circuit that connects the first pipe and the second pipe with each other via the oil return port,
the oil return mechanism being configured to return, via the oil return port and the oil return circuit, lubricating oil included in the high-pressure refrigerant from the first pipe to the second pipe,

the filter portion in the differential pressure generation mechanism being configured to collect, by the differential pressure, the lubricating oil that is in a form of mist included in the high-pressure refrigerant, and
the first pipe allowing the collected lubricating oil to move downstream along an internal wall of the first pipe.

2. The oil separator of claim 1 , wherein
an outflow pipe positioned downstream in the first pipe is vertically located, and
a pipe diameter of the outflow pipe and a pipe diameter of an inflow pipe positioned upstream in the first pipe are set in such a manner that a flow rate in the outflow pipe is less than or equal to a zero penetration flow rate for the lubricating oil.

3. The oil separator of claim 1 , wherein
the first pipe is a U-shaped pipe or an L-shaped pipe.

4. The oil separator of claim 3 , wherein
when the first pipe is the U-shaped pipe, the oil return port is located lowermost in the first pipe.

5. The oil separator of claim 1 , wherein
the filter portion is a demister.

6. The oil separator of claim 1 , wherein
a flow rectifier is located in the first pipe and upstream of the differential pressure generation mechanism.

7. The oil separator of claim 6 , wherein
the flow rectifier is a strainer.

8. A refrigeration cycle apparatus
in which the oil separator of claim 1 is located downstream of the compressor.

9. The refrigeration cycle apparatus of claim 8 , further comprising:
a flow control valve that is located in the third pipe of the oil separator and has an opening degree that is adjustable; and
a controller configured to control the opening degree of the flow control valve, wherein
the controller is configured to set the opening degree of the flow control valve to be smaller than a reference value, in an operation mode in which the differential pressure between a pressure of refrigerant close to the discharge port of the compressor and a pressure of refrigerant close to the suction port of the compressor is smaller than a reference value.

10. The refrigeration cycle apparatus of claim 8 , further comprising:
an oil return valve that is located in the oil return circuit of the oil separator and has an opening degree that is adjustable; and
a controller configured to control the opening degree of the oil return valve, wherein
the controller is configured to set the opening degree of the oil return valve to be greater than a reference value, in an operation mode in which a frequency of the compressor increases.

Assignees

• Mitsubishi Electric Corp

Inventors

• Kato Shun
• Ishiyama Hiroki
• Shimazu yusuke
• Ito Daisuke

Classifications

• F25B31/004 Primary

  oil recirculating arrangements · CPC title

• F25B39/02

  Evaporators · CPC title

• F25B43/02

  for separating lubricants from the refrigerant · CPC title

• F25B49/02

  for compression type machines, plants or systems · CPC title

• F25B43/003

  Filters · CPC title