COOLING SYSTEM

• US 20200132345A1
• Filed: 10/30/2018
• Published: 04/30/2020
• Est. Priority Date: 10/30/2018
• Status: Active Grant

• Current Assignee: Heatcraft Refrigeration Products LLC (Lennox International Incorporated)
• Original Assignee: Heatcraft Refrigeration Products LLC (Lennox International Incorporated)
• Inventors: Sun, Xi, Zha, Shitong
• Granted Patent: US 11,193,699 B2
• Time in Patent Office: Days
• CPC Class Codes: F25B 1/10 with multi-stage compression with cascade operation F25B7/00
• CPC Class Codes: F25B 2341/0012 Ejectors with the cooled primary flow at high pressure
• CPC Class Codes: F25B 2341/0016 Ejectors for creating an oil recirculation
• CPC Class Codes: F25B 2400/23 Separators
• CPC Class Codes: F25B 31/004 oil recirculating arrangements
• CPC Class Codes: F25B 43/02 for separating lubricants from the refrigerant
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25B 5/02 arranged in parallel
• CPC Class Codes: F25B 9/08 using ejectors F25B9/10 takes precedence

Abstract

An apparatus includes a high side heat exchanger, a flash tank, a first load, a first oil separator, and a first compressor. The high side heat exchanger removes heat from a refrigerant. The flash tank stores the refrigerant. The first load uses the refrigerant to cool a first space proximate the first load. During a first mode of operation, the first oil separator separates an oil from the refrigerant from the first load and directs the refrigerant to an ejector. The ejector directs the refrigerant from the high side heat exchanger and the refrigerant form the first oil separator to the flash tank. The flash tank directs the refrigerant from the first oil separator to the first compressor. The first compressor compresses the refrigerant from the flash tank. During a second mode of operation, the first oil separator directs the oil separated from the refrigerant to the first compressor.

Claims

1. An apparatus comprising:

a high side heat exchanger configured to remove heat from a refrigerant;

a flash tank configured to store the refrigerant from the high side heat exchanger;

a first load configured to use the refrigerant from the flash tank to cool a first space proximate the first load;

a first oil separator; and

a first compressor;

during a first mode of operation;

the first oil separator configured to;

separate an oil from the refrigerant from the first load;

direct the refrigerant to an ejector, the ejector configured to direct the refrigerant from the high side heat exchanger and the refrigerant form the first oil separator to the flash tank;

the flash tank configured to direct the refrigerant from the first oil separator to the first compressor; and

the first compressor configured to compress the refrigerant from the flash tank; and

during a second mode of operation, the first oil separator configured to direct the oil separated from the refrigerant to the first compressor.

2. The apparatus of claim 1, wherein the first oil separator is configured to direct the oil separated from the refrigerant to a suction header during the second mode of operation, the suction header configured to direct the oil to the first compressor.

3. The apparatus of claim 1, wherein the first oil separator is configured to direct the oil separated from the refrigerant to an oil reservoir during the second mode of operation, the oil reservoir configured to direct the refrigerant to the first compressor.

4. The apparatus of claim 3, further comprising a second oil separator configured to separate an oil from the refrigerant from the first compressor and to direct the oil separated from the refrigerant from the first compressor to the oil reservoir.

5. The apparatus of claim 1, further comprising a second oil separator configured to separate an oil from the refrigerant from the first compressor.

6. The apparatus of claim 1, further comprising:

a second load configured to use the refrigerant from the flash tank to cool a second space proximate the second load; and

a second compressor configured to compress the refrigerant from the second load, the first compressor further configured to compress the refrigerant from the second compressor.

7. The apparatus of claim 1, further comprising a valve configured to prevent the oil separated from the refrigerant from flowing to the first oil separator during the second mode of operation.

8. A method comprising:

removing, by a high side heat exchanger, heat from a refrigerant;

storing, by a flash tank, the refrigerant from the high side heat exchanger;

using, by a first load, the refrigerant from the flash tank to cool a first space proximate the first load;

during a first mode of operation;

separating, by an oil separator, an oil from the refrigerant from the first load;

directing, by the oil separator, the refrigerant to an ejector;

directing, by the ejector, the refrigerant from the high side heat exchanger and the refrigerant form the first oil separator to the flash tank;

directing, by the flash tank, the refrigerant from the first oil separator to the first compressor; and

compressing, by the first compressor, the refrigerant from the flash tank; and

during a second mode of operation, directing, by the first oil separator, the oil separated from the refrigerant to the first compressor.

9. The method of claim 8, further comprising:

directing, by the first oil separator, the oil separated from the refrigerant to a suction header during the second mode of operation; and

directing, by the suction header, the oil to the first compressor.

10. The method of claim 8, further comprising:

directing, by the first oil separator, the oil separated from the refrigerant to an oil reservoir during the second mode of operation; and

directing, by the oil reservoir, the refrigerant to the first compressor.

11. The method of claim 10, further comprising:

separating, by a second oil separator, an oil from the refrigerant from the first compressor; and

directing, by the second oil separator, the oil separated from the refrigerant from the first compressor to the oil reservoir.

12. The method of claim 8, further comprising separating, by a second oil separator, an oil from the refrigerant from the first compressor.

13. The method of claim 8, further comprising:

using, by a second load, the refrigerant from the flash tank to cool a second space proximate the second load;

compressing, by a second compressor, the refrigerant from the second load; and

compressing, by the first compressor, the refrigerant from the second compressor.

14. The method of claim 8, further comprising preventing, by a valve, the oil separated from the refrigerant from flowing to the first oil separator during the second mode of operation.

15. A system comprising:

a high side heat exchanger configured to remove heat from a refrigerant;

a flash tank configured to store the refrigerant from the high side heat exchanger;

a first load configured to use the refrigerant from the flash tank to cool a first space proximate the first load;

a second load configured to use the refrigerant from the flash tank to cool a second space proximate the second load;

a first oil separator;

a first compressor; and

a second compressor configured to compress the refrigerant from the second load;

during a first mode of operation;

the first oil separator configured to;

separate an oil from the refrigerant from the first load;

direct the refrigerant to an ejector, the ejector configured to direct the refrigerant from the high side heat exchanger and the refrigerant form the first oil separator to the flash tank;

the flash tank configured to direct the refrigerant from the first oil separator to the first compressor; and

the first compressor configured to compress the refrigerant from the flash tank and the refrigerant from the second compressor; and

during a second mode of operation, the first oil separator configured to direct the oil separated from the refrigerant to the first compressor.

16. The system of claim 15, wherein the first oil separator is configured to direct the oil separated from the refrigerant to a suction header during the second mode of operation, the suction header configured to direct the oil to the first compressor.

17. The system of claim 15, wherein the first oil separator is configured to direct the oil separated from the refrigerant to an oil reservoir during the second mode of operation, the oil reservoir configured to direct the refrigerant to the first compressor.

18. The system of claim 17, further comprising a second oil separator configured to separate an oil from the refrigerant from the first compressor and to direct the oil separated from the refrigerant from the first compressor to the oil reservoir.

19. The system of claim 15, further comprising a second oil separator configured to separate an oil from the refrigerant from the first compressor.

20. The system of claim 15, further comprising a valve configured to prevent the oil separated from the refrigerant from flowing to the first oil separator during the second mode of operation.