Cooling system

Patent metadata

Field	Value
Publication number	US-11035599-B2
Application number	US-201916460585-A
Country	US
Kind code	B2
Filing date	Jul 2, 2019
Priority date	Jul 2, 2019
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

An apparatus includes a flash tank that stores a refrigerant, a first load that uses the refrigerant to cool a first space, second and third loads, first and second compressors, and a valve. During a first mode of operation: the second load uses the refrigerant to cool a second space, the third load uses the refrigerant to cool a third space, the second compressor compresses the refrigerant from the second and third loads, and the first compressor compresses the refrigerant from the first load and the second compressor. During a second mode of operation: the second compressor compresses the refrigerant from the second load and directs the compressed refrigerant to the third load to defrost the third load and the valve prevents the refrigerant at the third load from flowing to the flash tank until a pressure of the refrigerant at the third load exceeds a threshold.

First claim

What is claimed is:

1. An apparatus comprising:
a high side heat exchanger configured to remove heat from a refrigerant;
a flash tank configured to store the refrigerant;
a first load configured to use the refrigerant from the flash tank to cool a first space proximate the first load;
a second load;
a third load;
a first compressor;
a second compressor; and
a valve,
during a first mode of operation:
the second load is configured to use the refrigerant from the flash tank to cool a second space proximate the second load;
the third load is configured to use the refrigerant from the flash tank to cool a third space proximate the third load;
the second compressor configured to compress the refrigerant from the second load and the third load; and
the first compressor configured to compress the refrigerant from the first load and the second compressor, and

during a second mode of operation:
the second compressor configured to compress the refrigerant from the second load and to direct the compressed refrigerant to the third load to defrost the third load; and
the valve configured to prevent the refrigerant at the third load from flowing to the flash tank until a pressure of the refrigerant at the third load exceeds a threshold.

2. The apparatus of claim 1 , wherein, during the second mode of operation, the refrigerant at the third load condenses.

3. The apparatus of claim 2 , wherein, during the second mode of operation, the flash tank is further configured to direct a liquid portion of the refrigerant from the third load to at least one of the first load and the second load.

4. The apparatus of claim 2 , wherein, during the second mode of operation, the flash tank is further configured to direct a vapor portion of the refrigerant from the third load to the first compressor.

5. The apparatus of claim 1 , wherein the valve is configured to direct a flash gas from the flash tank to the first compressor.

6. The apparatus of claim 1 , wherein, during the second mode of operation, the refrigerant from the third load is directed through the valve before the refrigerant reaches the flash tank.

7. The apparatus of claim 1 , wherein, during the second mode of operation, the second load is further configured to use the refrigerant from the flash tank to cool the second space.

8. A method comprising:
removing, by a high side heat exchanger, heat from a refrigerant;
storing, by a flash tank, the refrigerant;
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:
using, by a second load, refrigerant from the flash tank to cool a second space proximate the second load;
using, by a third load, the refrigerant from the flash tank to cool a third space proximate the third load;
compressing, by a second compressor, the refrigerant from the second load and the third load; and
compressing, by a first compressor, the refrigerant from the first load and the second compressor, and

during a second mode of operation:
compressing, by the second compressor, the refrigerant from the second load;
directing, by the second compressor, the compressed refrigerant to the third load to defrost the third load; and
preventing, by a valve, the refrigerant at the third load from flowing to the flash tank until a pressure of the refrigerant at the third load exceeds a threshold.

9. The method of claim 8 , wherein, during the second mode of operation, the refrigerant at the third load condenses.

10. The method of claim 9 , further comprising, during the second mode of operation, directing, by the flash tank, a liquid portion of the refrigerant from the third load to at least one of the first load and the second load.

11. The method of claim 9 , further comprising, during the second mode of operation, directing, by the flash tank, a vapor portion of the refrigerant from the third load to the first compressor.

12. The method of claim 8 , further comprising directing, by the valve, a flash gas from the flash tank to the first compressor.

13. The method of claim 8 , wherein, during the second mode of operation, the refrigerant from the third load is directed through the valve before the refrigerant reaches the flash tank.

14. The method of claim 8 , further comprising, during the second mode of operation, using, by the second load, the refrigerant from the flash tank to cool the second space.

15. A system comprising:
a flash tank configured to store a refrigerant;
a first load configured to use the refrigerant from the flash tank to cool a first space proximate the first load;
a second load;
a third load;
a first compressor;
a second compressor; and
a valve,
during a first mode of operation:
the second load is configured to use the refrigerant from the flash tank to cool a second space proximate the second load;
the third load is configured to use the refrigerant from the flash tank to cool a third space proximate the third load;
the second compressor configured to compress the refrigerant from the second load and the third load; and
the first compressor configured to compress the refrigerant from the first load and the second compressor, and

during a second mode of operation:
the second compressor configured to compress the refrigerant from the second load and to direct the compressed refrigerant to the third load to defrost the third load; and
the valve configured to prevent the refrigerant at the third load from flowing to the flash tank until a pressure of the refrigerant at the third load exceeds a threshold.

16. The system of claim 15 , wherein, during the second mode of operation, the refrigerant at the third load condenses.

17. The system of claim 16 , wherein, during the second mode of operation, the flash tank is further configured to direct a liquid portion of the refrigerant from the third load to at least one of the first load and the second load.

18. The system of claim 16 , wherein, during the second mode of operation, the flash tank is further configured to direct a vapor portion of the refrigerant from the third load to the first compressor.

19. The system of claim 15 , wherein the valve is configured to direct a flash gas from the flash tank to the first compressor.

20. The system of claim 15 , wherein, during the second mode of operation, the refrigerant from the third load is directed through the valve before the refrigerant reaches the flash tank.

Assignees

• Heatcraft Refrigeration Products Llc

Inventors

• Hollister Michael
• Zha Shitong

Classifications

• F25B1/10 Primary

  with multi-stage compression (with cascade operation F25B7/00) · CPC title

• F25B47/02 Primary

  Defrosting cycles · CPC title

• F25B47/022

  hot gas defrosting · CPC title

• F25B5/02

  arranged in parallel · CPC title

• F25B2700/11

  Sensor to detect if defrost is necessary · CPC title