Evaporative cooling enhanced cold storage system

• US 5,056,588 A
• Filed: 12/28/1990
• Issued: 10/15/1991
• Est. Priority Date: 12/28/1990
• Status: Expired due to Term

• Current Assignee: Instatherm Company
• Original Assignee: Instatherm Company
• Inventors: Carr, Peter
• Primary Examiner(s): DAVIS JR, ALBERT
• Application Number:
  US07/635,301
• Time in Patent Office: 291 Days
• Field of Search: 165/10, 165/18, 165/42, 165/104.11, 62/430, 62/91, 62/92, 62/93, 62/406
• US Class Current: 165/10
• CPC Class Codes: B60H 1/3202 using evaporation, i.e. not including a compressor, e.g. involving fuel or water evaporation B60H1/3235 takes precedence; in general F25B19/00, F25D7/00
• CPC Class Codes: F24F 2006/146 using pressurised water for spraying
• CPC Class Codes: F24F 3/14 by humidification; by dehumidification
• CPC Class Codes: F24F 5/0035 using evaporation
• CPC Class Codes: Y02B 30/54 Free-cooling systems

Abstract

The invention provides an evaporatively enhanced cold storage system wherein a warm air stream is cooled and the cooled air stream is thereafter passed into contact with a cold storage unit. Moisture is added to the cooled air stream prior to or during contact of the cooled air stream with the cold storage unit to effect enhanced cooling of the cold storage unit due to evaporation of all or a portion of the added moisture. Preferably at least a portion of the added moisture comprises water condensed during the cooling of the warm air stream.

Claims

1. An air conditioning and cold storage process comprising the steps:

(a) cooling a warm air stream;

(b) passing the cooled air stream, in the presence of added moisture, in indirect heat exchange contact with a cold storage medium, the cold storage medium being at a temperature which is the same as or greater than the temperature of the cooled air stream to thereby vaporize at least a portion of the added moisture and effect enhanced cooling of the cold storage medium; and

(c) recovering a cooled air stream comprising vaporized moisture from indirect heat exchange contact with the cold storage medium and passing the cooled air stream comprising vaporized moisture to an air conditioned enclosure.

2. The process of claim 1 wherein the cold storage medium comprises water and a liquified gas capable of forming a gas hydrate.

3. The process of claim 2 wherein the water and gas are provided within a plurality of sealed containers and further comprising at least one mechanical device positioned for free movement within each of said containers.

4. The process of claim 2 wherein the cold storage medium additionally comprises an emulsifier for enhancing mixing of the liquified gas and water.

5. The process of claim 1 further comprising the steps;

collecting water condensed by cooling of the warm air stream in step (a), and thereafter adding at least a portion of the collected, condensed water to the cooled air stream prior to or during indirect heat exchange contact of the cooled air stream with the cold storage medium to provide said added moisture.

6. The process of claim 5 additionally comprising the steps of providing a separate reservoir of water and adding at least a portion of the water from the separate source to the cooled air stream prior to or during indirect heat exchange contact of the cooled air stream with the cold storage medium.

7. The process of claim 5 additionally comprising the step of heating at least a portion of the cooled air stream provided in step (a) prior to passing the cooled air stream into indirect heat exchange contact with the cold storage medium and prior to the addition of the collected, condensed water to the cooled air stream.

8. The process of claim 5 wherein the cold storage medium is provided as an array of a plurality of sealed containers containing a water and a gas capable of forming a gas hydrate.

9. The process of claim 5 wherein the cold storage medium is contained within a plurality of groups of individually sealed containers with the groups being disposed in a series arrangement, each group of individually sealed containers containing a hydrate forming gas which is different from the hydrate forming gas in at least one of the other groups of the containers and such that the hydrate forming transition temperature is not uniform among the groups.

10. The process of either of claim 8 wherein at least one movable device is provided within each of the individually sealed containers.

11. The process of claim 5 wherein at least a portion of the collected, condensed water is added to the cooled air stream by spraying the water into the cooled air stream prior to indirect heat exchange contact of the cooled air stream with the cold storage medium.

12. The process of claim 5 wherein at least a portion of the collected condensed water is added to the cooled air stream during indirect heat exchange contact of the cooled air stream with the cold storage medium.

13. The process of claim 1 wherein all or a portion of the cooled air stream comprising vaporized moisture recovered in step (c) is recirculated at least once through steps (a) and (b) prior to being passed to the air conditioned enclosure.

14. An air conditioning process comprising the steps:

(a) cooling a warm air stream sufficiently to condense water out of the air stream and provide a cooled air stream;

(b) collecting at least a portion of the condensate water condensed from cooling of the warm air stream;

(c) passing the cooled air stream into contact with a unit containing a hydrate forming gas cold storage medium, the unit being at a temperature which is the same as or greater than the temperature of the cooled air stream; and

(d) adding at least a portion of the collected condensate water to the cooled air stream prior to or during contact of the cooled air stream with the unit containing the hydrate forming gas cold storage medium.

15. The process of claim 14 additionally including the step of recovering the cooled air stream contacted with the unit containing the hydrate forming gas cold storage medium and passing the recovered cooled air stream into an air conditioned enclosure.

16. The process of claim 14 additionally comprising the steps of providing a source of water separate from the collected condensate water and adding the water from the separate source to the cooled air stream prior to or during contact of the cooled air stream with the unit containing the hydrate forming gas cold storage medium.

17. The process of claim 14 wherein the unit containing the hydrate forming gas cold storage medium is provided in the form of a plurality of individually sealed containers containing water and the hydrate forming gas.

18. The process of claim 17 additionally comprising at least one movable device positioned within each of the individually sealed containers.

19. The process of claim 14 wherein the hydrate forming gas cold storage medium additionally includes at least one emulsifying agent.

20. The process of claim 14 additionally comprising the step of recovering the cooled air stream contacted with the unit containing the hydrate forming gas cold storage medium and recirculating at least a portion of the cooled air stream to step (a).

21. An air conditioning and cold storage system comprising:

(a) air conditioning means cooling a warm air stream;

(b) cold storage means disposed downstream of the air conditioning means arranged for heat exchange contact with the cooled air stream;

(c) moisturizing means adapted and arranged for increasing the moisture content of the cooled air stream prior to or during heat exchange contact of the cooled air stream with the cold storage means; and

(d) recovery and supply means for recovering cooled air having an increased moisture content from contact with the cold storage means and for supplying the cooled air having increased moisture content to an air conditioned enclosure.

22. The system of claim 21 further comprising condensate collecting means for collecting water condensed by the air conditioning means and supply means for supplying at least a portion of the water collected by the condensate collection means to the moisturizing means.

23. The system of claim 21 wherein the supply means comprises an insulated supply line connected to the moisturizing means and a pump for pumping condensate through the insulated supply line to the moisturizing means.

24. The system of claim 21 wherein the cold storage means comprises a plurality of individually sealed containers containing water and a gas capable of forming a gas hydrate with the water.

25. The system of claim 24 further comprising movable means positioned within each of the containers for providing mechanical movement within the containers.

26. The system of claim 24 wherein the water and gas in the containers additionally comprises an emulsifying agent.

27. The system of claim 21 additionally comprising a recirculation means for recirculating all or a portion of the cooled air having increased moisture content recovered in step (d) to the air conditioning means.

28. The system of claim 21 further comprising a second water supply means connected to the moisturizing means for supplying water to the moisturizing means.

29. An air conditioning and cold storage system comprising:

(a) an air duct;

(b) an air conditioning means comprising a cooling coil positioned within the air duct for providing a cooled air stream through the air duct;

(c) cold storage means disposed in the air duct downstream of the cooling coil and arranged for heat exchange contact with the cooled air stream from the cooling coil; and

(d) a spray nozzle connected to a water supply source, the spray nozzle being disposed in the air duct and positioned to spray water onto the cold storage means.

30. The system of claim 29 wherein the cold storage means comprises a plurality of individually sealed containers containing a cold storage medium.

31. The system of claim 29 further comprising condensate collecting means for collecting moisture condensate condensed by the cooling coil in the air duct, the condensate collecting means constituting all or a portion of the water supply connected to the spray nozzle disposed in the air duct.

32. The system of claim 31 wherein the cold storage medium is a cold storage phase change medium.

33. The system of claim 32 wherein the cold storage medium comprises water and a gas capable of forming a gas hydrate with the water.

34. The system of claim 33 wherein the cold storage medium additionally comprises an emulsifying agent.

35. The system of claim 33 wherein the individually sealed containers comprise a movable means positioned within each of the containers for providing mechanical movement within the sealed container.

40. The system of claim 35 wherein the cold storage means comprises a plurality of groups of individually sealed containers, each of the containers containing water and a gas capable of forming a gas hydrate with the water and with the containers of each group having a hydrate forming gas which is different from the hydrate forming gas in at least one of the other groups of containers such that the hydrate forming transition temperature is not uniform among the groups.

36. A vehicle air conditioning and cold storage system comprising:

(a) an air duct including a fan for advancing air therethrough;

(b) air conditioning means including a cooling coil in the duct for cooling the air as it advances through the duct;

(c) condensate collecting means connected to the cooling coil for collecting moisture condensate from the cooling coil;

(d) a heating means positioned within the duct downstream of the cooling coil operable for heating all or a portion of the air flowing through the duct;

(e) cold storage means disposed in the duct downstream of the heating means and arranged for heat exchange contact with air flowing through the duct, the cold storage means including a gas hydrate cold storage medium; and

(f) moisturizing means disposed within the duct downstream of the heating means and upstream of or adjacent the cold storage means, the moisturizing means being connected to the condensate collecting means and adapted to add all or a portion of the condensate collected by the condensate collecting means to air flowing through the duct.

37. The system of claim 36 wherein the cold storage means comprises a plurality of individually sealed containers, each of the containers containing water and a gas capable of forming a gas hydrate with the water.

38. The system of claim 37 wherein each of the sealed containers additionally includes a movable means positioned inside of the container.

39. The system of claim 37 wherein each of the containers additionally contain an emulsifying agent.