Air-cooled ammonia refrigeration systems and methods

Patent metadata

Field	Value
Publication number	US-11466905-B2
Application number	US-202016858835-A
Country	US
Kind code	B2
Filing date	Apr 27, 2020
Priority date	Jul 15, 2016
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

In some embodiments, an air-cooled ammonia refrigeration system comprises: an air-cooled condenser comprising a heat exchanger and at least one axial fan; an evaporator coupled to the air-cooled condenser; a subcooler positioned between the air-cooled condenser and the evaporator; a compressor coupled to the evaporator; an oil cooler coupled to the compressor; a water system coupled to the air-cooled condenser, the water system comprising a water source, a water pump, and a plurality of spray nozzles positioned below the air-cooled condenser; and a control circuit coupled to the air-cooled condenser and the water system, the control circuit configured to pulse atomized water through the plurality of spray nozzles to a surface of the air-cooled condenser when a head pressure of the air-cooled condenser is higher than a predetermined value.

First claim

What is claimed is:

1. A system for controlling head pressure of an air-cooled condenser, the system comprising:
an air-cooled condenser configured to condense vaporous ammonia to form liquid ammonia;
a water system coupled to the air-cooled condenser, the water system comprising a water source, a water pump, and a plurality of spray nozzles; and
a control circuit coupled to the air-cooled condenser and the water system, the control circuit configured to:
determine a head pressure of the air-cooled condenser; and
when the head pressure of the air-cooled condenser is higher than a predetermined value, provide atomized water through the plurality of spray nozzles to a surface of the air-cooled condenser such that the water evaporates upon contact with the surface of the air-cooled condenser.

2. The system of claim 1 , wherein none of the water provided to the surface of the air-cooled condenser accumulates as wastewater.

3. The system of claim 1 , wherein the control circuit pulses the water through the plurality of spray nozzles to the surface of the air-cooled condenser.

4. The system of claim 1 , wherein the air-cooled condenser comprises a finned tube heat exchanger and at least one fan.

5. The system of claim 4 , wherein the finned tube heat exchanger has a tube diameter of at least about 0.5 inches and a fin density of at least about 12 fins per inch.

6. The system of claim 1 , wherein a plurality of legs is configured to elevate the air-cooled condenser at least about 13 feet above a roof surface.

7. The system of claim 1 , wherein a plurality of legs is configured to elevate the air-cooled condenser at least about 25 feet above a ground surface.

8. A method of controlling head pressure of an air-cooled condenser, the method comprising:
providing an air-cooled condenser configured to condense vaporous ammonia to form liquid ammonia;
providing a water system coupled to the air-cooled condenser, the water system comprising a water source, a water pump, and a plurality of spray nozzles;
determining, using a control circuit, a head pressure of the air-cooled condenser; and
when the head pressure of the air-cooled condenser is higher than a predetermined value, providing, using the control circuit, atomized water through the plurality of spray nozzles to a surface of the air-cooled condenser such that the water evaporates upon contact with the surface of the air-cooled condenser.

9. The method of claim 8 , wherein none of the water provided to the surface of the air-cooled condenser accumulates as wastewater.

10. The method of claim 8 , wherein the water is pulsed through the plurality of spray nozzles to the surface of the air-cooled condenser.

11. The method of claim 8 , wherein the air-cooled condenser comprises a finned tube heat exchanger and at least one fan.

12. The method of claim 11 , wherein the finned tube heat exchanger has a tube diameter of at least about 0.5 inches and a fin density of at least about 12 fins per inch.

13. The method of claim 8 , wherein a plurality of legs is configured to elevate the air-cooled condenser at least about 13 feet above a roof surface.

14. The method of claim 8 , wherein a plurality of legs is configured to elevate the air-cooled condenser at least about 25 feet above a ground surface.

15. A system for controlling head pressure of an air-cooled condenser, the system comprising:
an air-cooled condenser comprising a finned tube heat exchanger and at least one fan, the air-cooled condenser configured to condense vaporous ammonia to form liquid ammonia;
a water system coupled to the air-cooled condenser, the water system comprising a water source, a water pump, and a plurality of spray nozzles positioned adjacent the air-cooled condenser; and
a control circuit coupled to the air-cooled condenser and the water system, the control circuit configured to spray atomized water through the plurality of spray nozzles to a surface of the air-cooled condenser when a head pressure of the air-cooled condenser is higher than a predetermined value, wherein the water evaporates upon contact with the surface of the air-cooled condenser.

16. The system of claim 15 , wherein none of the water provided to the surface of the air-cooled condenser accumulates as wastewater.

17. The system of claim 15 , wherein the control circuit pulses the water through the plurality of spray nozzles to the surface of the air-cooled condenser.

18. The system of claim 15 , wherein the finned tube heat exchanger has a tube diameter of at least about 0.5 inches and a fin density of at least about 12 fins per inch.

19. The system of claim 15 , wherein a plurality of legs is configured to elevate the air-cooled condenser at least about 13 feet above a roof surface.

20. The system of claim 15 , wherein a plurality of legs is configured to elevate the air-cooled condenser at least about 25 feet above a ground surface.

Assignees

• Walmart Apollo Llc

Inventors

• Baker Steven Kent
• Braz Marcos Rente

Classifications

• F25B15/04 Primary

  the refrigerant being ammonia evaporated from aqueous solution {(F25B15/025 takes precedence)} · CPC title

• F25B39/00

  Evaporators; Condensers · CPC title

• F28D5/00

  Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, using the cooling effect of natural or forced evaporation · CPC title

• Y02B30/62

  Absorption based systems · CPC title

• F25B37/00

  Absorbers; Adsorbers (boiler-absorbers F25B35/00) · CPC title