Method and apparatus for latent heat extraction

• US 5,228,302 A
• Filed: 06/19/1992
• Issued: 07/20/1993
• Est. Priority Date: 11/12/1991
• Status: Expired due to Term

• Current Assignee: Kenneth L. Eiermann
• Original Assignee: Kenneth L. Eiermann
• Inventors: Eiermann, Kenneth L.
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US07/901,504
• Time in Patent Office: 396 Days
• Field of Search: 62/90, 62/176.5, 62/173, 62/238.6
• US Class Current: 62/90
• CPC Class Codes: F24F 11/00 Control or safety arrangements
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/84 using valves
• CPC Class Codes: F24F 11/85 using variable-flow pumps
• CPC Class Codes: F24F 12/00 Use of energy recovery systems in air conditioning, ventilation or screening with both heat and humidity transfer between supplied and exhausted air F24F3/147
• CPC Class Codes: F24F 2005/0025 using heat exchange fluid storage tanks
• CPC Class Codes: F24F 2011/0002 for admittance of outside air
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2110/20 Humidity
• CPC Class Codes: F24F 2203/021 Compression cycle
• CPC Class Codes: F24F 2221/183 combined with a hot-water boiler
• CPC Class Codes: F24F 2221/54 Heating and cooling, simultaneously or alternatively
• CPC Class Codes: F24F 2221/56 Cooling being a secondary aspect
• CPC Class Codes: F24F 3/00 Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems room units F24F1/00
• CPC Class Codes: F24F 3/153 with subsequent heating, i.e. with the air, given the required humidity in the central station, passing a heating element to achieve the required temperature
• CPC Class Codes: F25B 29/003 of the compression type system

Abstract

A method and apparatus for improved latent heat extraction combines a run-around coil system with a condenser heat recovery system to enhance the moisture removing capability of a conventional vapor compression air conditioning unit. The run-around coil system exchanges energy between the return and supply air flows of the air conditioning unit. Energy recovered in the condenser heat recovery system is selectively combined with the run-around system energy extracted from the return air flow to reheat the supply air stream for downstream humidity control. A control system regulates the relative proportions of the extracted return air flow energy and recovered heat energy delivered to the reheat coil for efficient control over moisture in the supply air flow. Auxiliary energy in the form of electric heat energy is further added to the recovered heat energy for additional reheat use.

Claims

1. A moisture control apparatus for use with a fluid compression air conditioning system having a compressor for compressing a compressible fluid, and a cooling coil where the compressible fluid decompresses absorbing thermal energy from a return air flow as a cooled supply air flow, the moisture control apparatus comprising:

a working fluid;

precooling coil means in said return air flow for exchanging thermal energy between the return air flow and the working fluid;

reheat coil means in said supply air flow for exchanging thermal energy between the return air flow and the working fluid;

heat exchange means for exchanging thermal energy between the compressible fluid and the working fluid;

fluid conduit means for containedly directing the working fluid through a series arrangement of said precooling coil means, said heat exchange means, and said reheat coil means;

fluid pump means for motivating a flow of the working fluid through said series arrangement; and

,

regulating means for regulating said working fluid flow through said precooling and reheat coil.

2. A moisture control apparatus according to claim 1 wherein said regulating means comprises a control valve connected to said fluid conduit means in said series arrangement.

3. A moisture control apparatus according to claim 2 further comprising bypass conduit means, connected to said control valve in parallel with said heat exchange means and in parallel with a series combination of said precooling coil means and said reheat coil means, for selectively circulating a first portion of the working fluid as a bypass flow through said series combination of said precooling coil means and said reheat coil means.

4. A moisture control apparatus according to claim 3 wherein said control valve comprises a first input port connected to said fluid conduit means for receiving a first flow of said working fluid from said heat exchange means, a second input port connected to said bypass conduit means for receiving said bypass flow of said working fluid from said precooling coil means, an output port connected to said fluid conduit means for selectively exhausting said first and bypass flows from said control valve to said reheat coil means, and valving means for selectively metering said first and bypass flows through said control valve as a metered flow.

5. A moisture control apparatus according to claim 4 wherein said fluid pump means comprises a variable speed drive fluid pump.

6. A moisture control apparatus according to claim 5 further comprising thermal energy storage means connected to said fluid conduit means and operatively associated with said working fluid and said heat exchange means for recovering and storing thermal energy from said compressible fluid and selectively delivering the stored thermal energy to said working fluid.

7. An apparatus for use with an air conditioning system having a cooling coil disposed between a return air flow upstream of said coil and a supply air flow downstream of said coil, the apparatus comprising:

first exchange means in said return air flow for communicating thermal energy from the return air flow to a thermal energy storage medium;

second exchange means in said supply air flow for communicating thermal energy to the supply air flow from said thermal energy storage medium;

a tank storing a first volume of said thermal energy storage medium;

means for heating the thermal energy storage medium stored in said tank; and

,

means for communicating a flow of said thermal energy storage medium successively through each of said first exchange means, said second exchange means and said tank.

8. The apparatus according to claim 7 wherein said means for heating comprises an electric heating element for selectively heating said first volume of said thermal energy storage medium in said tank responsive to an energy management lock out signal received by the apparatus.

9. The apparatus according to claim 7 wherein said means for communicating comprises a conduit serially connecting said first exchange means, said second exchange means and said tank in a closed loop.

10. The apparatus according to claim 9 further comprising means for motivating a first flow of said thermal energy storage medium through said serially connected first and second exchange means.

11. The apparatus according to claim 10 wherein said motivating means comprises a fluid pump means for pumping said thermal energy storage medium in said conduit as said first flow.

12. The apparatus according to claim 11 wherein said conduit comprises a bypass path in parallel with i) said tank and ii) said serially connected first and second exchange means, the bypass path communicating a bypass flow of said thermal energy storage medium therethrough.

13. The apparatus according to claim 12 further comprising regulating means for regulating said first and bypass flows of said thermal energy storage medium.

14. The apparatus according to claim 13 wherein said regulating means comprises a valve means connecting said conduit and said bypass path for selectively metering said first flow and said bypass flow in selective proportions.

15. The apparatus according to claim 14 wherein said valve means comprises a first input port connected to said conduit for receiving a second flow of said thermal energy storage means from said tank, a second input port connected to said bypass path for receiving said bypass flow of said thermal energy storage medium, and, an output port connected to said conduit for selectively exhausting said second and bypass flows from said valve means to said second exchange means as said first flow.

16. The apparatus according to claim 15 wherein said fluid pump means comprises a variable speed drive fluid pump.

17. The apparatus according to claim 15 wherein said heating means comprises an electric heating element for heating said first volume of said thermal energy storage medium in said tank.

18. The apparatus according to claim 15 wherein said electric heating element comprises means for selectively heating the thermal energy storage medium stored in said tank responsive to an energy management lock out signal received by the apparatus.

19. The apparatus according to claim 15 wherein said means for heating comprises a waste heat recovery means for exchanging thermal energy between a compressible fluid of said air conditioning system and the thermal energy storage medium.

20. A moisture control apparatus for use with an air conditioning system having a cooling coil receiving a return air flow and absorbing thermal energy therefrom as a supply air flow, the apparatus comprising:

first means for exchanging thermal energy between the return air flow and a working fluid;

second means for exchanging thermal energy between the working fluid and the supply air flow;

means for introducing thermal energy into said working fluid from an energy source other than from said return air flow;

first fluid conduit means for containedly directing said working fluid flow through a series arrangement of said first means, said thermal energy introducing means and said second means as a first fluid flow; and

,

means for flowing said working fluid through said first fluid conduit means as said first fluid flow.

21. The moisture control apparatus according to claim 20 wherein said first means comprises a precooling coil in said return air flow for exchanging thermal energy from said return air flow to said working fluid and said second means comprises a reheat coil in said supply air flow for exchanging thermal energy from said working fluid to said supply air flow.

22. The moisture control apparatus according to claim 20 wherein said thermal energy introducing means comprises an electric heating means for introducing thermal energy into said working fluid from an electric energy source.

23. The moisture control apparatus according to claim 20 wherein said thermal energy introducing means comprises an electric heating means for selectively introducing thermal energy into said working fluid responsive to an energy management signal received by the apparatus.

24. The moisture control apparatus according to claim 20 said thermal energy introducing means comprises a gas heating means for introducing thermal energy into said working fluid from a combustible gas energy source.

25. The moisture control apparatus according to claim 20 wherein said thermal energy introducing means comprises heat exchange means for introducing thermal energy into said working fluid from waste energy given off by a compressible fluid of said air conditioning system.

26. The moisture control apparatus according to claim 20 wherein said fluid flowing means comprising fluid pump means for motivating a first flow of said working fluid through said first means, said second means and said thermal energy introducing means.

27. The moisture control apparatus according to claim 20 further comprising means for regulating said working fluid flow through said first means, said second means and said thermal energy introducing means.

28. The moisture control apparatus according to claim 20 further comprising second fluid conduit means connected to said first fluid conduit means and in parallel with said thermal energy introducing means and in parallel with a series combination of said first means and said second means, for containedly directing a bypass fluid flow through said series combination of said first means and said second means for bypassing said thermal energy introducing means.

29. The moisture control apparatus according to claim 28 further comprising means for throttling at least one of said first fluid flow and said bypass fluid flow through said first fluid conduit means and said bypass conduit means respectively.

30. The moisture control apparatus according to claim 29 wherein said throttling means comprises valve means for selectively metering at least one of said first fluid flow and said bypass fluid flow through said first conduit means and said bypass conduit means respectively.

31. The moisture control apparatus according to claim 30 wherein said first means comprises a precooling coil in said return air flow for exchanging thermal energy from said return air flow to said working fluid and said second means comprises a reheat coil in said supply air flow for exchanging thermal energy from said working fluid to said supply air flow.

32. The moisture control apparatus according to claim 30 wherein said thermal energy introducing means comprises an electric heating means for selectively introducing thermal energy into said working fluid from an electric energy source responsive to an energy management lock out signal received by the apparatus.

33. The moisture control apparatus according to claim 30 wherein said thermal energy introducing means comprises a gas heating means for introducing thermal energy into said working fluid form a combustible gas energy source.

34. The moisture control apparatus according to claim 30 wherein said thermal energy introducing means comprises heat exchange means for introducing thermal energy into said working fluid from waste energy given off by a compressible fluid of said air conditioning system.

35. The moisture control apparatus according to claim 30 wherein said working fluid flowing means comprises fluid pump means for motivating said first fluid and said bypass fluid flow.

36. A method of moisture control for use with a fluid compression air conditioning system having a compressor for compressing a compressible fluid, and a cooling coil where the compressible fluid decompresses absorbing thermal energy from a return air flow as a cooled supply air flow, the method comprising the steps of:

providing a working fluid;

exchanging thermal energy between the return air flow and the working fluid using a precooling coil in said return air flow;

exchanging thermal energy between the working fluid and the supply air flow using a reheat coil in said supply air flow;

exchanging thermal energy between the compressible fluid and the working fluid using a heat exchanger;

motivating a flow of the working fluid through said precooling coil, said reheat coil, and said heat exchanger by containedly directing the working fluid through a series arrangement of said precooling coil, said heat exchanger, and said reheat coil using a fluid conduit; and

,

regulating said working fluid flow through said precooling and reheat coils.

37. The method according to claim 36 wherein said regulating step includes the step of regulating said working fluid using a control valve connected to said fluid conduit in said series arrangement.

38. The method according to claim 37 further comprising the steps of:

providing a bypass conduit connected to said control valve in parallel with said heat exchanger and in parallel with a series combination of said precooling coil and said reheat coil; and

,

selectively circulating a first portion of the working fluid as a bypass flow through said bypass conduit and said series combination of said precooling coil and said reheat coil.

39. The method according to claim 38 further comprising the steps of:

receiving a first flow of said working fluid from said heat exchanger into a first input port of said control valve connected to said fluid conduit;

receiving said bypass flow of said working fluid from said precooling coil into a second input port of said control valve connected to said bypass conduit;

selectively exhausting said first and bypass flows from said control valve to said reheat coil through an output port of said control valve connected to said fluid conduit; and

,

selectively metering said first and bypass flows through said control valve as a metered flow.

40. The method according to claim 39 wherein the motivating step includes motivating said working fluid flow using a variable speed drive fluid pump.

41. The method according to claim 40 further comprising the step of:

recovering thermal energy from said compressible fluid of said fluid compression air conditioning system;

storing the recovered thermal energy in a thermal energy storage device connected to said fluid conduit and operatively associated with said working fluid and said heat exchanger;

selectively delivering the stored thermal energy to said working fluid.

42. A method of moisture control for use with an air conditioning system having a cooling coil disposed between a return air flow upstream of said coil and a supply air flow downstream of said coil, the method comprising the steps of:

providing a thermal energy storage medium;

communicating thermal energy from the return air flow to said thermal energy storage medium using a first exchange means in said return air flow;

communicating thermal energy to the supply air flow from said thermal energy storage medium using a second exchange means in said supply air flow;

storing a first volume of said thermal energy storage medium in a tank;

heating the stored first volume of thermal energy storage medium; and

,

communicating a flow of said thermal energy storage medium through said first exchange means, said second exchange means and said tank.

43. A method according to claim 42 wherein the heating step includes selectively heating said first volume of said thermal energy storage medium in said tank responsive to an energy management lock out signal received by the apparatus.

44. A method according to claim 42 wherein the thermal energy storage medium flow communicating step includes communicating said thermal energy storage medium flow through a conduit serially connecting said first exchange means, said second exchange means and said tank in a closed loop.

45. A method according to claim 44 further comprising the step of motivating a first flow of said thermal energy storage medium through said serially connected first and second exchange means.

46. A method according to claim 45 wherein said motivating step includes pumping said thermal energy storage medium in said conduit as said first flow using a fluid pump.

47. A method according to claim 46 further comprising the steps of:

providing a bypass conduit path in parallel with i) said tank and ii) said serially connected first and second exchange means; and

,

communicating a bypass flow of said thermal energy storage medium through the bypass conduit path.

48. A method according to claim 47 further comprising the step of selectively regulating at least one of said first and bypass flows of said thermal energy storage medium.

49. A method according to claim 48 wherein said selectively regulating step includes the step of selectively metering said first flow and said bypass flow in selective proportions using a valve connecting said conduit and said bypass path.

50. A method according to claim 49 further comprising the steps of:

receiving a second flow of said thermal energy storage means from said tank at a first input port of said valve connected to said conduit;

receiving said bypass flow of said thermal energy storage medium at a second input port of said valve connected to said bypass path;

selectively exhausting said second and bypass flows from an output port of said valve to said second exchange means as said first flow.

51. A method according to claim 50 wherein said motivating step includes pumping said thermal energy storage medium in said conduit as said first flow using a variable speed drive fluid pump.

52. A method according to claim 50 wherein said heating step includes heating the stored first volume of thermal energy storage medium using an electric heating element in said tank.

53. A method according to claim 50 wherein said heating step includes selectively heating the thermal energy storage medium stored in said tank responsive to an energy management lock out signal received by the apparatus.

54. A method according to claim 50 wherein said heating step includes:

recovering energy in a waste heat recovery device exchanging thermal energy between a compressible fluid of said air conditioning system and the thermal energy storage medium; and

,

heating the stored first volume of thermal energy storage medium using the recovered energy.

55. A method of moisture control for use with an air conditioning system having a cooling coil receiving a return air flow and absorbing thermal energy therefrom as a supply air flow, the method comprising the steps of:

exchanging thermal energy between the return air flow and a working fluid using a first heat exchanger;

exchanging thermal energy between the working fluid and the supply air flow using a second heat exchanger;

introducing thermal energy into said working fluid from an energy source other than from said return air flow using a thermal energy introducing device;

containedly directing said working fluid flow through a series arrangement of said first means, said thermal energy introducing means and said second means as a first fluid flow using a first fluid conduit; and

,

flowing said working fluid through said first fluid conduit as said first fluid flow.

56. The moisture control method according to claim 55 wherein:

said exchanging step using said first heat exchanger includes exchanging thermal energy from said return air flow to said working fluid using a precooling coil in said return air flow; and

,

said exchanging step using said second heat exchanger includes exchanging thermal energy from said working fluid to said supply air flow using a reheat coil in said supply air flow.

57. The moisture control method according to claim 55 wherein said thermal energy introducing step includes introducing thermal energy into said working fluid from an electric energy source.

58. The moisture control method according to claim 55 wherein said thermal energy introducing step includes selectively introducing thermal energy into said working fluid responsive to an energy management signal received by the apparatus.

59. The moisture control method according to claim 55 wherein said thermal energy introducing step includes introducing thermal energy into said working fluid from a combustible gas energy source.

60. The moisture control method according to claim 55 wherein said thermal energy introducing step includes introducing thermal energy into said working fluid from recovered waste energy given off by a compressible fluid of said air conditioning system.

61. The moisture control method according to claim 55 wherein said flowing step includes motivating a first flow of said working fluid through said first heat exchanger, said second heat exchanger and said thermal energy introducing device using a fluid pump.

62. The moisture control method according to claim 55 further comprising the step of regulating said working fluid flow through said first heat exchanger, said second heat exchanger and said thermal energy introducing device.

63. The moisture control method according to claim 55 further comprising the step of containedly directing a bypass fluid flow through a second fluid conduit connected to said first fluid conduit in parallel with said thermal energy introducing device and also in parallel with a series combination of said first heat exchanger and said second heat exchanger.

64. The moisture control method according to claim 63 further comprising the step of throttling at least one of said first fluid flow and said bypass fluid flow through said first fluid conduit and said bypass conduit respectively.

65. The moisture control method according to claim 64 wherein said throttling step includes selectively metering at least one of said first fluid flow and said bypass fluid flow through said first conduit and said bypass conduit respectively.

66. The moisture control method according to claim 65 wherein:

said exchanging step using said first heat exchanger includes exchanging thermal energy from said return air flow to said working fluid using a precooling coil in said return air flow; and

,

said exchanging step using said second heat exchanger includes exchanging thermal energy from said working fluid to said supply air flow using a reheat coil in said supply air flow.

67. The moisture control method according to claim 65 wherein said thermal energy introducing step includes introducing thermal energy into said working fluid from an electric energy source.

68. The moisture control method according to claim 65 wherein said thermal energy introducing step includes introducing thermal energy into said working fluid from a combustible gas energy source.

69. The moisture control method according to claim 65 wherein said thermal energy introducing step includes introducing thermal energy into said working fluid from recovered waste energy given off by a compressible fluid of said air conditioning system.

70. The moisture control method according to claim 65 wherein said flowing step includes motivating a first flow of said working fluid through said first heat exchanger, said second heat exchanger and said thermal energy introducing device using a fluid pump.