Refrigeration system and oil recovery method for the same

Patent metadata

Field	Value
Publication number	US-12072127-B2
Application number	US-202217834052-A
Country	US
Kind code	B2
Filing date	Jun 7, 2022
Priority date	Jun 17, 2021
Publication date	Aug 27, 2024
Grant date	Aug 27, 2024

Abstract

A refrigeration system includes a compressor, a condenser, a throttling device, and an evaporator, which are connected in sequence to form a cooling circuit, the refrigeration system further includes an oil recovery system which includes: an operation chamber, which includes a first port communicating with an oil-containing position in the refrigeration system through a first pipeline, and a second port communicating with a bearing chamber or a bearing lubrication pipeline of the compressor through a second pipeline; and a main piston in the operation chamber, the main piston reciprocating in the operation chamber to perform an extraction stroke and a discharge stroke; in the extraction stroke, an oil-containing refrigerant in the oil-containing position in the refrigeration system is extracted to the operation chamber; and in the discharge stroke, the oil-containing refrigerant in the operation chamber is delivered to the bearing chamber or the bearing lubrication pipeline of the compressor.

First claim

What is claimed is:

1. A refrigeration system, comprising: a compressor, a condenser, a throttling device, and an evaporator, all of which are connected in sequence to form a cooling circuit, wherein the refrigeration system further comprises an oil recovery system comprising:
an operation chamber, which comprises a first port communicating with an oil-containing position in the refrigeration system through a first pipeline, and a second port communicating with a bearing chamber or a bearing lubrication pipeline of the compressor through a second pipeline; and
a main piston in the operation chamber, the main piston reciprocating in the operation chamber to perform an extraction stroke and a discharge stroke; wherein in the extraction stroke, an oil-containing refrigerant in the oil-containing position in the refrigeration system is extracted to the operation chamber; and in the discharge stroke, the oil-containing refrigerant in the operation chamber is delivered to the bearing chamber or the bearing lubrication pipeline of the compressor;
wherein the main piston is connected to a first side of a control piston through a connecting rod, there is a first control chamber at the first side of the control piston, and a second control chamber at a second side of the control piston; the first control chamber and the second control chamber are alternatively connected to a first pressure fluid source and a second pressure fluid source, and there is a pressure difference between the first pressure fluid source and the second pressure fluid source, thereby driving the control piston to reciprocate together with the main piston to perform the extraction stroke and the discharge stroke;
wherein the first pressure fluid source is from the evaporator, and the second pressure fluid source is from the condenser.

2. The refrigeration system according to claim 1 ,
wherein a first one-way valve that only allows a fluid to flow from the oil-containing position to the first port is provided on the first pipeline or on an end cover at an end of the operation chamber, and a second one-way valve that only allows the fluid to flow from the second port to the bearing chamber or the bearing lubrication pipeline of the compressor is provided on the second pipeline or the end cover.

3. The refrigeration system according to claim 1 , wherein the oil-containing position in the refrigeration system is in an oil-collecting cavity inside the compressor or in the evaporator.

4. The refrigeration system according to claim 1 , wherein the main piston is driven by an electric actuator.

5. The refrigeration system according to claim 1 , wherein the first control chamber is located between a back side of the main piston and the first side of the control piston, and the control piston has a larger area of action than the main piston.

6. The refrigeration system according to claim 1 , wherein:
the evaporator is connected to the first control chamber through a first valve and is connected to the second control chamber through a second valve, and the condenser is connected to the first control chamber through a third valve and is connected to the second control chamber through a fourth valve; or
the evaporator is connected to the first control chamber and the second control chamber respectively through a first three-way valve, and the condenser is connected to the first control chamber and the second control chamber respectively through a second three-way valve; or
the evaporator, the condenser, the first control chamber and the second control chamber are connected through a four-way valve.

7. The refrigeration system according to claim 6 , wherein the refrigeration system further comprises:
a sensor, which is configured to sense a position of the control piston or the main piston; and
a controller in communication with the sensor, which is configured to operate at least one valve based on the position of the control piston or the main piston provided by the sensor so that the first control chamber and the second control chamber are alternatively connected to the first pressure fluid source and the second pressure fluid source.

8. A refrigeration system, comprising: a compressor, a condenser, a throttling device, and an evaporator, all of which are connected in sequence to form a cooling circuit, wherein the refrigeration system further comprises an oil recovery system comprising:
an operation chamber, which comprises a first port communicating with an oil-containing position in the refrigeration system through a first pipeline, and a second port communicating with a bearing chamber or a bearing lubrication pipeline of the compressor through a second pipeline; and
a main piston in the operation chamber, the main piston reciprocating in the operation chamber to perform an extraction stroke and a discharge stroke; wherein in the extraction stroke, an oil-containing refrigerant in the oil-containing position in the refrigeration system is extracted to the operation chamber; and in the discharge stroke, the oil-containing refrigerant in the operation chamber is delivered to the bearing chamber or the bearing lubrication pipeline of the compressor;
wherein the main piston is connected to a first side of a control piston through a connecting rod, there is a first control chamber at the first side of the control piston, and a second control chamber at a second side of the control piston; the first control chamber and the second control chamber are alternatively connected to a first pressure fluid source and a second pressure fluid source, and there is a pressure difference between the first pressure fluid source and the second pressure fluid source, thereby driving the control piston to reciprocate together with the main piston to perform the extraction stroke and the discharge stroke;
wherein the first control chamber is located between a back side of the main piston and the first side of the control piston, and the control piston has a larger area of action than the main piston;
wherein the oil recovery system further comprises an additional operation chamber, and the additional operation chamber comprises a first port communicating with the oil-containing position in the refrigeration system through a third pipeline, and a second port communicating with the bearing chamber or the bearing lubrication pipeline of the compressor through a fourth pipeline; and
an additional main piston in the additional operation chamber, wherein the additional main piston is connected to the second side of the control piston through a connecting rod, the second control chamber is located between a back side of the additional main piston and the second side of the control piston, and the control piston has a larger area of action than the additional main piston; when the main piston is performing the extraction stroke, the additional main piston performs the discharge stroke to deliver the oil-containing refrigerant from the additional operation chamber to the bearing chamber or the bearing lubrication pipeline of the compressor, and when the main piston is performing the discharge stroke, the additional main piston performs the extraction stroke to extract the oil-containing refrigerant in the oil-containing position in the refrigeration system to the additional operation chamber.

Assignees

• Carrier Corp

Inventors

• Guo Zhen
• Deng Kai
• Sishtla Vishnu
• Wu Yingqin
• Yu Lei

Classifications

• F25B2500/16

  Lubrication · CPC title

• F25B49/02

  for compression type machines, plants or systems · CPC title

• F25B31/004 Primary

  oil recirculating arrangements · CPC title

• F25B41/20

  Disposition of valves, e.g. of on-off valves or flow control valves (expansion valves F25B41/31) · CPC title

• F25B11/02

  as expanders (F25B9/06 takes precedence) · CPC title