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Efficiency thermoelectrics utilizing convective heat flow

Imported: 24 Feb '17 | Published: 06 Jan '04

Lon E. Bell

USPTO - Utility Patents

Abstract

An improved efficiency thermoelectric system is disclosed wherein convection is actively facilitated through a thermoelectric array. Thermoelectrics are commonly used for cooling and heating applications. Thermal power is convected through a thermoelectric array toward at least one side of the thermoelectric array, which leads to increased efficiency. Several different configurations are disclosed to provide convective thermal power transport, using a convective medium. In addition, a control system is disclosed which responds to one or more inputs to make adjustments to the thermoelectric system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B depict a conventional thermoelectric device;

FIG. 2 depicts a conventional thermoelectric device in a conventional fluid heating or cooling application;

FIG. 3 depicts a conventional thermoelectric element for use in cooling a material or component;

FIG. 4 depicts an efficiency measure of various thermoelectric materials;

FIG. 5 illustrates a generalized conditions diagram of conventional thermoelectric devices;

FIG. 6 illustrates a generalized block diagram of a thermoelectric system;

FIGS. 7A and 7B depict an embodiment of a conventional thermoelectric system;

FIGS. 8A and 8B depict an embodiment of a thermoelectric system employing convective heat transport in accordance with the present invention;

FIGS. 9A and 9B depict another embodiment of a thermoelectric system in accordance with the present invention using a liquid thermoelectric material for convective heat transport;

FIG. 10 depicts a detailed illustration of a portion of the TE element array showing a tubular TE element;

FIG. 11 depicts a detailed illustration of a portion of the TE element array showing a tubular TE element with a heat transfer feature;

FIGS. 12A and 12B depict a detailed illustration of a portion of the TE element array showing a TE element composed of nested concentric tubes;

FIG. 13 depicts a detailed illustration of a portion of the TE element array showing convection along the length of the TE elements;

FIGS. 14A and 14B depict a detailed illustration of a portion of the TE element array showing convection along the length of the TE elements with additional mixing created by a heat transfer feature;

FIGS. 15A and 15B depict a detailed illustration of a portion of the TE element array showing a TE element with a honeycomb structure;

FIGS. 16 A and

16B depict another embodiment of a thermoelectric system in accordance with the present invention using a solid material as the convective heat transfer medium;

FIG. 17 depicts an existing device used to both heat and cool that can be improved in its efficiency by convective heat transfer in accordance with the present invention; and

FIG. 18 depicts an embodiment with convective heat transfer of an improvement of the device of FIG. 17 in accordance with the present invention.

FIG. 19 illustrates a control system for use with thermoelectric systems of the present invention.

FIGS. 20A-20D illustrate several variations of thermoelectric elements configured in a manner to vary their thermal and electrical characteristics.

Claims

1. A thermoelectric system comprising:

2. The thermoelectric system of claim 1, wherein the at least one convective medium flows through at least some of the thermoelectric elements.

3. The thermoelectric system of claim 2, wherein at least some of the thermoelectric elements are permeable.

4. The thermoelectric system of claim 3, wherein at least some of the thermoelectric elements are porous.

5. The Thermoelectric system of claim 2, wherein at least some of the thermoelectric elements are tubular.

6. The Thermoelectric system of claim 2, wherein at least some of the thermoelectric elements are a honeycomb structure.

7. The thermoelectric system of claim 2, wherein the convective medium flows through at least some of the thermoelectric elements in a single general direction.

8. The thermoelectric system of claim 7, wherein the convective medium flows generally from between the first and the second sides toward the first side or toward the second side.

9. The thermoelectric system of claim 2, wherein the convective medium flows generally from the first side to the second side.

10. The thermoelectric system of claim 2, wherein the convective medium flows generally from the second side to the first side.

11. The thermoelectric system of claim 2, wherein the convective medium flows through at least some of the thermoelectric elements in at least two general directions.

12. The thermoelectric system of claim 11, wherein the convective medium flows generally from between the first side and the second side toward the first side and toward the second side.

13. The thermoelectric system of claim 1, wherein the array is configured such that the convective medium flows along at least some of the thermoelectric elements.

14. The thermoelectric system of claim 13, wherein the convective medium flows along at least some of the thermoelectric elements in a single general direction.

15. The thermoelectric system of claim 14, wherein the convective medium flows generally from between the first side and the second side toward the first side or toward the second side.

16. The thermoelectric system of claim 13, wherein the convective medium flows generally from the first side to the second side.

17. The thermoelectric system of claim 13, wherein the convective medium flows generally from the second side to the first side.

18. The thermoelectric system of claim 13, wherein the convective medium flows along at least some of the thermoelectric elements in at least two general directions.

19. The thermoelectric system of claim 18, wherein the convective medium flows generally from between the first side and the second side toward the first side and toward the second side.

20. The thermoelectric system of claim 13, wherein at least some of the thermoelectric elements form concentric tubes with the convective medium flow between the concentric tubes.

21. The thermoelectric system of claim 20, wherein the tubes concentrically alternate between p-type thermoelectric material and n-type thermoelectric material.

22. The thermoelectric system of claim 20, wherein a first set of concentric tubes are of the same first type of thermoelectric material, and a second set of concentric tubes are of the same second type of thermoelectric material.

23. The thermoelectric system of claim 1, wherein at least part of the convective medium is thermoelectric material, said convective medium thermoelectric material also forming at least some of the thermoelectric elements.

24. The thermoelectric system of claim 1, wherein at least part of the convective medium is thermoelectric material, said convective medium thermoelectric material forming a first portion of at least some of the thermoelectric elements, and a solid thermoelectric material forming a second portion of the same thermoelectric elements.

25. The thermoelectric system of claim 24, wherein the solid thermoelectric material is tubular, and the convective medium thermoelectric material flows through the solid tubular thermoelectric material, the combination forming the at least some thermoelectric elements.

26. The thermoelectric system of claim 1, wherein at least part of the convective medium is a fluid.

27. The thermoelectric system of claim 26, wherein at least a portion of the convective medium is air.

28. The thermoelectric system of claim 1, wherein at least part of the convective medium is a solid.

29. The thermoelectric system of claim 1, wherein at least part of the convective medium is a mixture of fluid and solid.

30. The thermoelectric system of claim 1, wherein a first plurality of the thermoelectric elements are configured for convective heat transport of a first type and a second plurality of the thermoelectric elements are configured for convective heat transport of a second type.

31. The thermoelectric system of claim 30, wherein the first plurality are thermoelectric elements of a first conductivity type and the second plurality are thermoelectric elements of a second conductivity type.

32. The thermoelectric system of claim 1, wherein at least some of the thermoelectric elements do not utilize convection.

33. The thermoelectric system of claim 32, wherein the thermoelectric elements that do not utilize convection are of a first conductivity type and wherein the thermoelectric elements that utilize convection are of a second conductivity type.

34. The thermoelectric system of claim 1, wherein at least a portion of the array comprises at least one heat transfer feature that improves heat transfer between at least some of the convective medium and at least some of the thermoelectric elements.

35. The thermoelectric system of claim 34, wherein at least some of the thermoelectric elements are tubular, and wherein the heat transfer feature is inside at least some of the tubular thermoelectric elements.

36. The thermoelectric system of claim 34, wherein the heat transfer feature is between at least some of the thermoelectric elements.

37. The thermoelectric system of claim 34 wherein the heat transfer feature is a convective medium flow disturbing feature.

38. The thermoelectric system of claim 1, wherein the system is used for cooling.

39. The thermoelectric system of claim 1, wherein the system is used for heating.

40. The thermoelectric system of claim 1, wherein the system is used for both cooling and heating.

41. A method of improving efficiency in a thermoelectric system having a plurality of thermoelectric elements forming a thermoelectric array having at least one first side and at least one second side exhibiting a temperature gradient between them during operation of the thermoelectric array, the method comprising the step of actively convecting heat through at least a portion of the array in a generally steady-state manner.

42. The method of claim 41, wherein the step of convecting heat comprises flowing at least one convective medium through at least a portion of the thermoelectric array.

43. The method of claim 42, wherein the step of flowing comprises flowing at least some of the convective medium through at least some of the thermoelectric elements.

44. The method of claim 43, wherein at least some of the thermoelectric elements are permeable.

45. The method of claim 44, wherein at least some of the thermoelectric elements are porous.

46. The method of claim 43, wherein at least some of the thermoelectric elements are tubular.

47. The method of claim 43, wherein at least some of the thermoelectric elements are a honeycomb structure.

48. The method of claim 42, wherein the step of flowing comprises flowing the convective medium generally from the first side to the second side.

49. The method of claim 42, wherein the step of flowing comprises flowing the convective medium generally from between the first side and the second side toward the first side or toward the second side.

50. The method of claim 42, wherein the step of flowing comprises flowing the convective medium in at least two general directions.

51. The method of claim 50, wherein the step of flowing comprises flowing the convective medium generally from between the first side and the second side toward the first side and toward the second side.

52. The method of claim 51, wherein the step of flowing comprises flowing at least some of the convective medium through at least some of the thermoelectric elements.

53. The method of claim 51, wherein the step of flowing comprises flowing at least some of the convective medium along at least some of the thermoelectric elements.

54. The method of claim 43, wherein at least some of the thermoelectric elements form concentric tubes, the step of flowing comprising flowing at least some of the convective medium between the concentric tubes.

55. The method of claim 42, wherein thermoelectric material comprises at least a portion of the convective medium, further comprising the step of forming at least some of the thermoelectric elements with said convective medium.

56. The method of claim 42, wherein a thermoelectric material comprises at least a portion of the convective medium, further comprising the step of forming a first portion of at least some of the thermoelectric elements with said convective material.

57. The method of claim 56, further comprising the step of flowing the convective medium thermoelectric material through other thermoelectric material in a hollow form, the combination of the flowing convective medium thermoelectric material and the thermoelectric material in a hollow form forming the at least some thermoelectric elements.

58. The method of claim 42, wherein at least a portion of the convective medium is a fluid.

59. The method of claim 58, wherein at least a portion of the convective medium is air.

60. The method of claim 42, wherein at least a portion of the convective medium is a solid.

61. The method of claim 42, wherein at least a portion of the convective medium is a mixture of fluid and solid.

62. The method of claim 42, wherein the step of actively convecting heat comprises convecting heat through a first portion of the array in a first manner and through a second portion of the array in a second manner.

63. The method of claim 62, wherein the first portion of the array comprises a plurality of thermoelectric elements of a first conductivity type and the second portion of the array comprises a plurality are thermoelectric elements of a second conductivity type.

64. The method of claim 41, wherein at least some of the thermoelectric elements do not utilize convection.

65. The method of claim 64, wherein the thermoelectric elements that do not utilize convection are of a first conductivity type and wherein the thermoelectric elements that utilize convection are of a second conductivity type.

66. The method of claim 41, wherein the thermoelectric array is used for cooling.

67. The method of claim 41, wherein the thermoelectric array is used for heating.

68. The method of claim 41, wherein the thermoelectric array is used for both cooling and heating.

69. A thermoelectric system comprising:

70. The thermoelectric system of claim 69, wherein the at least one characteristic impacts the convective heat transport, and wherein the adjustment improves efficiency by adjusting the characteristic.

71. The thermoelectric system of claim 69, wherein the control system varies movement of at least some of the convective medium in response to said input.

72. The thermoelectric system of claim 69, wherein the control system varies at least the current through at least some of the thermoelectric elements.

73. The thermoelectric system of claim 69, wherein the at least one input comprises at least one external sensor.

74. The thermoelectric system of claim 69, wherein the at least one input comprises at least one sensor internal to the thermoelectric array.

75. The thermoelectric system of claim 69, wherein the at least one input comprises at least one sensor internal to the thermoelectric array, at least one external sensor and at least one user selectable input.

76. The thermoelectric system of claim 69, wherein the at least one input is a user selectable input.

77. The thermoelectric system of claim 69, wherein at least one controller operates in accordance with at least one algorithm responsive to the at least one input to control the at least one output.