Ice thermal storage coil systems and methods

• US 6,101,821 A
• Filed: 05/21/1999
• Issued: 08/15/2000
• Est. Priority Date: 05/22/1998
• Status: Expired due to Term

• Current Assignee: Evapco Incorporated
• Original Assignee: Evapco International, Inc.
• Inventors: Cates, Robert E.
• Primary Examiner(s): Tapolcai, William E.
• Application Number:
  US09/316,404
• Time in Patent Office: 452 Days
• Field of Search: 62/59, 62/515, 62/139, 165/150, 165/151, 165/163
• US Class Current: 62/139
• CPC Class Codes: F25D 16/00 Devices using a combination of a cooling mode associated with refrigerating machinery with a cooling mode not associated with refrigerating machinery
• CPC Class Codes: F25D 3/005 combined with heat exchangers
• CPC Class Codes: F28D 20/021 the latent heat storage material and the heat-exchanging means being enclosed in one container F28D20/023 - F28D20/028 take precedence
• CPC Class Codes: F28D 7/08 the conduits being otherwise bent, e.g. in a serpentine or zig-zag F28D7/10 takes precedenceF28D7/0016 and F28D7/0033 take precedence
• CPC Class Codes: F28D 7/082 with serpentine or zig-zag configuration
• CPC Class Codes: F28D 7/085 in the form of parallel conduits coupled by bent portions
• CPC Class Codes: Y02E 60/14 Thermal energy storage

Abstract

The present invention is directed toward an ice-on-coil (IOC) thermal storage coil system and method utilizing "deep-tank" technology and dimensional relationship of coil height to coil width wherein the coil serpentine'"'"'s height (vertical tube dimension) is greater than the width (the horizontal dimension), and wherein all manifold and header joints are above, or just below the water surface of the tank, easily visible and accessible for maintenance, assembly, leak-checking or repair. Another aspect of the present ice-on-coil (IOC) thermal storage coil system and method is that, in some embodiments, the ice-coil tubes are never horizontal anywhere in the full coil height, but instead vertical tubes or "near-horizontal" sloped tubes are utilized which slope in an upward direction to facilitate air removal during filling of the coil with the coolant mixture.

Claims

1. A thermal storage coil apparatus for installation in an ice-on-coil thermal storage tank for transporting a refrigerant through said tank and on which ice cylinders are formed from water in the tank, comprising:

a serpentine tubular coil having an inlet end, an outlet end, and vertically spaced rows of elongate straight run sections adjoined by U-shaped curved portions at each end of each of said straight run sections, said coil having a height in a vertical direction greater than its width and length in a horizontal direction; and

a supply header connected with said inlet end for providing refrigerant to said coil and a return header connected at said outlet end for withdrawing refrigerant from said coil, wherein said coil height in a vertical direction is at least twice its width in a horizontal direction and said supply header and said return header are disposed at an upper end of said coil.

2. The thermal storage coil according to claim 1, wherein

said coil is formed of a single length of tubing bent to form said elongate straight run sections and U-shaped curved portions.

3. The thermal storage coil according to claim 1, wherein

said coil elongate straight run sections between said U-shaped portions are disposed at an angle relative to a horizontal axis sufficient to facilitate removal of air therefrom during filling said coil with the refrigerant.

4. A thermal storage coil apparatus for installation in an ice-on-coil thermal storage tank for transporting a refrigerant through said tank and on which ice cylinders are formed from water in the tank, comprising:

a serpentine tubular coil having an inlet end, an outlet end, and vertically spaced rows of elongate straight run sections adjoined by U-shaped curved portions at each end of each of said straight run sections, said coil having a height in a vertical direction greater than its width and length in a horizontal direction;

a supply header connected with said inlet end for providing refrigerant to said coil and a return header connected at said outlet end for withdrawing refrigerant from said coil,

wherein said coil has a supply section formed of a first plurality of rows of said elongate straight run sections and U-shaped curved portions extending downwardly from said inlet end with a U-shaped bend at a lowermost end thereof; and

a return section extending upwardly from said U-shaped bend formed of a second plurality of rows of said elongate straight run sections and U-shaped curved portions and terminating at said outlet end;

said supply section and said return section disposed in parallel spaced apart vertical planes with said U-shaped bend at said lowermost end extending between said parallel spaced vertical planes.

5. The thermal storage coil according to claim 4, wherein

said rows of elongate straight run sections of said supply section and said return section are offset and spaced apart a distance to form ice cylinders of predetermined diameter on adjacent straight run sections that are nested in a pattern to maximize ice build and minimize ice void areas.

6. The thermal storage coil according to claim 4, wherein

said coil has a pair of said supply sections disposed in a first vertical plane and a pair of said return sections disposed in a second vertical plane parallel to said first vertical plane;

each of said supply sections having an inlet end connected with said supply header and a U-shaped bend at a lowermost end;

each of said return sections extending upwardly from a respective said U-shaped compound bend and having an outlet end connected with said return header; and

each said U-shaped bend at said lowermost end extending between said first and second parallel spaced vertical planes.

7. The thermal storage coil according to claim 4, wherein said U-shaped bend at said lowermost end is a compound U-shaped bend curved about a horizontal axis and a vertical axis.

8. The thermal storage coil according to claim 4, wherein

said supply section and said return section are both formed of a single length of tubing bent to form said elongate straight run sections, said U-shaped curved portions, and said U-shaped bend at said lowermost portion.

9. A thermal storage coil apparatus for installation in an ice-on-coil thermal storage tank for transporting a refrigerant through said tank and on which ice cylinders are formed from water in the tank, comprising:

a serpentine tubular coil having an inlet end, an outlet end, and vertically spaced rows of elongate straight run sections adjoined by U-shaped curved portions at each end of each of said straight run sections, said coil having a height in a vertical direction greater than its width and length in a horizontal direction;

a supply header connected with said inlet end for providing refrigerant to said coil and a return header connected at said outlet end for withdrawing refrigerant from said coil; and

an enclosed box-like lower header having an inner chamber; and

said coil has a supply section formed of a first plurality of rows of said elongate straight run sections and U-shaped curved portions extending downwardly from said inlet end with a lowermost straight run section of said supply section having an open end in fluid communication with a lower portion of said lower header inner chamber;

said coil has a return section formed of a second plurality of rows of said elongate straight run sections and U-shaped curved portions with a lowermost straight run section of said return section having an open end in fluid communication with an upper portion of said lower header inner chamber, said return section extending upwardly from said lower header and terminating at said outlet end; and

said supply section and said return section disposed in parallel spaced apart vertical planes with said lower header extending between said parallel spaced vertical planes, wherein

said supply section and said return section are commonly joined with said inner chamber and said refrigerant and entrained fluids are conducted downwardly from said supply header through said coil supply section into said inner chamber and are transported upwardly through said coil return section and outwardly through said return header.

10. A thermal storage coil apparatus for installation in an ice-on-coil thermal storage tank for transporting a refrigerant through said tank and on which ice cylinders are formed from water in the tank, comprising:

a tubular coil formed of a plurality of vertical elongate U-shaped tubular members each having a straight supply leg with an inlet end at an upper end and a parallel laterally spaced return leg with an outlet end at an upper end, each of said supply and return legs adjoined by a U-shaped curved portion at a bottom end thereof and said coil having a height in a vertical direction greater than its width and length in a horizontal direction; and

a supply header connected with said inlet ends for providing refrigerant to said coil and a return header connected with said outlet ends for withdrawing refrigerant from said coil, wherein said coil height in a vertical direction is at least twice its width in a horizontal direction and said supply header and said return header are disposed at an upper end of said coil.

11. The thermal storage coil according to claim 10, wherein

said supply legs and said return legs are offset and spaced apart a distance to form ice cylinders of predetermined diameter on adjacent legs that are nested in a pattern to maximize ice build and minimize ice void areas.

12. A thermal storage coil apparatus for installation in an ice-on-coil thermal storage tank for transporting a refrigerant through said tank and on which ice cylinders are formed from water in the tank, comprising:

a tubular coil formed of a plurality of vertical elongate U-shaped tubular members each having a straight supply leg with an inlet end at an upper end and a parallel laterally spaced return leg with an outlet end at an upper end, each of said supply and return legs adjoined by a U-shaped curved portion at a bottom end thereof and said coil having a height in a vertical direction greater than its width and length in a horizontal direction; and

a supply header connected with said inlet ends for providing refrigerant to said coil, and a return header connected with said outlet ends for withdrawing refrigerant from said coil, wherein said plurality of vertical elongate U-shaped tubular members comprise an outer U-shaped tubular member having a straight supply leg with an inlet end at an upper end and a parallel laterally spaced straight return leg with an outlet end at an upper end adjoined by a wide U-shaped curved portion at a bottom end thereof; and

a plurality of inner said vertical elongate U-shaped tubular members having successively smaller U-shaped curved portions at a bottom end thereof nested between said supply leg and return leg of said outer U-shaped tubular member with all of said supply legs and return legs in generally parallel laterally spaced relation.

13. The thermal storage coil according to claim 12, wherein

said coil has a plurality of sets of said outer U-shaped tubular member and nested said inner U-shaped tubular members disposed in generally parallel spaced vertical planes;

and

each of said inlet ends connected with said supply header and each of said outlet ends connected with said return header.

14. The thermal storage coil according to claim 13, wherein

said straight supply legs and said return legs are offset and spaced apart a distance to form ice cylinders of predetermined diameter on adjacent legs that are nested in a pattern to maximize ice build and minimize ice void areas.

15. An ice-on-coil thermal storage system, comprising:

a generally rectangular ice tank suitable for containing water and having a bottom wall and opposed side walls;

a serpentine tubular coil having an inlet end, an outlet end, and vertically spaced rows of elongate straight run sections adjoined by U-shaped curved portions at each end of each of said straight run sections disposed in said tank for transporting a refrigerant through said tank and for forming ice cylinders thereon from water in said tank, said coil having a height in a vertical direction greater than its width and length in a horizontal direction; and

a supply header connected with said inlet end for providing refrigerant to said coil and a return header connected at said outlet end for withdrawing refrigerant from said coil, wherein said coil height in a vertical direction is at least twice its width in a horizontal direction and said supply header and said return header are disposed at an upper end of said coil.

16. The ice-on-coil thermal storage system according to claim 15, wherein

said coil straight run sections and U-shaped curved portions are submerged in water contained in said tank and said supply header and said return header are disposed above the water surface.

17. The ice-on-coil thermal storage system according to claim 15, wherein

said coil straight run sections and U-shaped curved portions are submerged in water contained in said tank and said supply header and said return header are just below the water surface.

18. The ice-on-coil thermal storage system according to claim 15, wherein

said supply header and said return header are disposed at a height relative to said tank bottom wall so as to be submerged just below the surface of water in said tank during periods of a fully ice-built condition and to be exposed above the water surface during periods of a fully ice-melted condition.

19. The ice-on-coil thermal storage system according to claim 15, wherein

said coil elongate straight run sections between said U-shaped portions are disposed at an angle relative to a horizontal axis sufficient to facilitate removal of air therefrom during filling said coil with the refrigerant.

20. An ice-on-coil thermal storage system, comprising:

a generally rectangular ice tank suitable for containing water and having a bottom wall and opposed side walls;

a serpentine tubular coil having an inlet end, an outlet end, and vertically spaced rows of elongate straight run sections adjoined by U-shaped curved portions at each end of each of said straight run sections disposed in said tank for transporting a refrigerant through said tank and for forming ice cylinders thereon from water in said tank said coil having a height in a vertical direction greater than its width and length in a horizontal direction; and

a supply header connected with said inlet end for providing refrigerant to said coil and a return header connected at said outlet end for withdrawing refrigerant from said coil, wherein

said coil has a supply section formed of a first plurality of rows of said elongate straight run sections and U-shaped curved portions extending downwardly from said inlet end with a U-shaped bend at a lowermost end thereof; and

a return section extending upwardly from said U-shaped bend formed of a second plurality of rows of said elongate straight run sections and U-shaped curved portions and terminating at said outlet end;

said supply section and said return section disposed in parallel spaced apart vertical planes with said U-shaped bend at said lowermost end extending between said parallel spaced vertical planes.

21. The ice-on-coil thermal storage system according to claim 20, wherein

said rows of elongate straight run sections of said supply section and said return section are offset and spaced apart a distance to form ice cylinders of predetermined diameter on adjacent straight run sections that are nested in a pattern to maximize ice build and minimize ice void areas.

22. An ice-on-coil thermal storage system, comprising:

a generally rectangular ice tank suitable for containing water and having a bottom wall and opposed side walls;

a tubular coil disposed in said tank for transporting a refrigerant through said tank and for forming ice cylinders thereon from water in said tank, said coil formed of a plurality of vertical elongate U-shaped tubular members each having a straight supply leg with an inlet end at an upper end and a parallel laterally spaced return leg with an outlet end at an upper end, each of said supply and return legs adjoined by a U-shaped curved portion at a bottom end thereof and said coil having a height in a vertical direction greater than its width and length in a horizontal direction; and

a supply header connected with said inlet ends for providing refrigerant to said coil and a return header connected with said outlet ends for withdrawing refrigerant from said coil, wherein said coil height in a vertical direction is at least twice its width in a horizontal direction and said supply header and said return header are disposed at an upper end of said coil.

23. The ice-on-coil thermal storage system according to claim 22, wherein

said supply header and said return header are dispposed at a height relative to said tank bottom wall so as to be submerged just below the surface of water in said tank during periods of a fully ice-built condition and to be exposed above the water surface during periods of a fully ice-melted condition.

24. The ice-on-coil thermal storage system according to claim 22, wherein

said supply legs and said return legs are offset and spaced apart a distance to form ice cylinders of predetermined diameter on adjacent legs that are nested in a pattern to maximize ice build and minimize ice void areas.

26. The ice-on-coil thermal storage system according to claim 22, wherein

said coil has a plurality of sets of said outer U-shaped tubular member and nested saidinner U-shaped tubular members disposed in generally parallel spaced vertical planes;

and

each of said inlet ends connected with said supply header and each of said outlet ends connected with said return header.

27. An ice-on-coil thermal storage system according to claim 26, wherein

said straight supply legs and said return legs are offset and spaced apart a distance to form ice cylinders of predetermined diameter on adjacent legs that are nested in a pattern to maximize ice build and minimize ice void areas.

25. An ice-on-coil thermal storage system comprising:

a generally rectangular ice tank suitable for containing water and having a bottom wall and opposed side walls;

a tubular coil disposed in said tank for transporting a refrigerant through said tank and for forming ice cylinders thereon from water in said tank, said coil formed of a plurality of vertical elongate U-shaped tubular members each having a straight supply leg with an inlet end at an upper end and a parallel laterally spaced return log with an outlet end at an upper end, each of said supply and return legs adjoined by a U-shaped curved portion at a bottom end thereof and said coil having a height in a vertical direction greater than its width and length in a horizontal direction; and

a supply header connected with said inlet ends for providing refrigerant to said coil and a return connected with said outlet ends for withdrawing refrigerant from said coil, wherein

said plurality of vertical elongate U-shaped tubular members comprise an outer U-shaped tubular member having a straight supply leg with an inlet end at an upper end and a parallel laterally spaced straight return leg with an outlet end at an upper end adjoined by a wide U-shaped curved portion at a bottom end thereof; and

a plurality of inner said vertical elongate U-shaped tubular members having successively smaller U-shaped curved portions at a bottom end thereof nested between said supply leg and retrun leg of said outer U-shaped tubular member with all of said supply legs and return legs in generally parallel laterally spaced relation.