Heat exchange enhancement

• US 20070230183A1
• Filed: 03/31/2006
• Published: 10/04/2007
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Hong Kong Applied Science And Technology Research Institute Co., Ltd.
• Original Assignee: Hong Kong Applied Science And Technology Research Institute Co., Ltd.
• Inventors: Shuy, Geoffrey
• Granted Patent: US 7,440,280 B2
• Time in Patent Office: Days
• US Class Current: 362/294
• CPC Class Codes: F21K 9/20 Light sources comprising attachment means
• CPC Class Codes: F21V 29/51 using condensation or evaporation of a fluid, e.g. heat pipes
• CPC Class Codes: F21V 29/677 the fans being used for discharging
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 29/89 Metals
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F28D 15/0233 the conduits having a particular shape, e.g. non-circular cross-section, annular F28D15/0241, F28D15/0266 take precedence
• CPC Class Codes: F28D 15/0275 Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 7/20009 using a gaseous coolant in electronic enclosures in cabinets of standardized dimensions H05K7/20536; in server cabinets H05K7/20709; in vehicle electronic casings H05K7/20845; in power control electronics H05K7/2089; in displays H05K7/20954
• CPC Class Codes: H05K 7/20154 Heat dissipaters coupled to components

Abstract

A heat exchange structure includes a plurality of elongated air ducts. The heat exchange structure has an exterior heat exchange surface and interior heat exchange surfaces, the interior surfaces being in the elongated air ducts. The heat exchange structure includes a plurality of heat generators that are distributed on the exterior heat exchange surface along an elongated direction of the air ducts, in which air flowing in the air duct is heated successively by heat from the heat generators, and air flow in the air duct is enhanced by buoyancy of heated air.

Claims

1. An apparatus comprising:

a heat exchange structure comprising a plurality of elongated air ducts, the heat exchange structure having an exterior heat exchange surface and interior heat exchange surfaces, the interior surfaces being in the elongated air ducts; and

a plurality of heat generators that are distributed on the exterior heat exchange surface along an elongated direction of the air ducts, such that in operation of the heat generators, air flowing in the air duct is heated successively by heat from the heat generators, the air flow in the air duct being enhanced by buoyancy of heated air.

2. The apparatus of claim 1 wherein the heat generators comprise electronic devices.

3. The apparatus of claim 2 wherein the electronic devices comprise light sources.

4. The apparatus of claim 2, further comprising signal lines that are attached to the exterior heat exchange surface, the electronic devices being attached to the signal lines.

5. The apparatus of claim 1 wherein the heat exchange structure comprises a metal structural section, heat flowing from the exterior heat exchange surface to the interior heat exchange surfaces through the metal structural section.

6. The apparatus of claim 1 wherein the heat exchange structure comprises a structural section and a thin layer of ceramic material attached to a surface of the structural section, the thin layer of material having a thickness less than 100 microns.

7. The apparatus of claim 6 wherein the thin layer of ceramic material comprises a first sub-layer that is substantially impermeable to air molecules and a second sub-layer that is at least partially permeable to air molecules.

8. The apparatus of claim 1, further comprising a fan to enhance air flow in the air ducts.

9. An apparatus for dissipating heat from electronic components, comprising:

a heat exchange structure comprising an elongated air duct and an interior heat exchange surface being in the air duct; and

signal lines coupled to an exterior heat exchange surface of the heat exchange structure, the signal lines defining locations for attaching the electronic components, the locations being disposed along an elongated direction of the air duct,

the heat exchange structure designed and configured to transfer heat from the electronic components through the exterior and interior heat exchange surfaces to air flowing in the air duct such that the air flowing in the air duct is heated successively by heat from the electronic components disposed along the elongated direction of the air duct, the air flow in the air duct being enhanced by buoyancy of heated air.

10. The apparatus of claim 9, further comprising the electronic components.

11. The apparatus of claim 9 wherein the heat exchange structure comprises a composite substrate that comprises a substrate and a thin layer of ceramic material attached to the substrate, the thin layer of ceramic material having a thickness less than 100 microns.

12. The apparatus of claim 9, further comprising a fan to enhance air flow in the air ducts.

13. A vehicle lamp comprising:

a heat exchange structure comprising a plurality of elongated air ducts, the air ducts comprising heat exchange surfaces configured to exchange thermal energy with air flowing in the air ducts; and

light emitting diodes that are distributed along an elongated direction of the air ducts, the light emitting diodes configured to transfer heat to the heat exchange surfaces in the air ducts to successively heat air as the air flows through the air ducts and enhance air flow in the air ducts by buoyancy of heated air;

wherein the vehicle lamp is configured to dissipate thermal energy generated by the light emitting diodes to the air flowing in the air ducts.

14. The vehicle lamp of claim 13 wherein the heat exchange structure comprises a structural section and a thin layer of ceramic material attached to the structural section, the thin layer of ceramic material having a thickness less than 100 μ

m.

15. The vehicle lamp of claim 13, further comprising an enclosure to form a water-tight chamber that encloses the light sources.

16. The vehicle lamp of claim 13, further comprising two water-tight chambers connected by a passage, one of the chambers enclosing the light sources and the other of the chambers enclosing electronic components to control the light sources, the passage allowing signal lines to pass, the signal lines connecting the light sources to the electronic components.

17. An MR-16 lamp comprising:

a light source comprising at least one light emitting diode (LED) module, each LED module comprising

a heat exchange structure comprising a plurality of elongated air ducts, the air ducts comprising heat exchange surfaces configured to exchange thermal energy with air flowing in the air ducts; and

light emitting diodes that are distributed along an elongated direction of the air ducts, the light emitting diodes configured to transfer heat to the heat exchange surfaces in the air ducts to successively heat air as the air flows through the air ducts and enhance air flow in the air ducts by buoyancy of heated air;

wherein each LED module is configured to dissipate thermal energy generated by the light emitting diodes to the air flowing in the air ducts.

18. The MR-16 lamp of claim 17 wherein the at least one LED module comprise two or more LED modules that are arranged such that the light emitting diodes of different LED modules face substantially the same direction.

19. The MR-16 lamp of claim 17 wherein the at least one LED module comprise two or more LED modules that are arranged such that the light emitting diodes of different LED modules face different directions.

20. The MR-16 lamp of claim 17 wherein the heat exchange structure comprises a structural section and a thin layer of ceramic material attached to the structural section, the thin layer of ceramic material having a thickness less than 100 μ

m.

21. A wall wash lamp comprising:

a heat exchange structure comprising a plurality of elongated air ducts, the air ducts comprising heat exchange surfaces configured to exchange thermal energy with air flowing in the air ducts; and

light emitting diodes that are distributed along an elongated direction of the air ducts, the light emitting diodes configured to transfer heat to the heat exchange surfaces in the air ducts and successively heat air as the air flows in the air ducts and enhance air flow in the air ducts by buoyancy of heated air;

wherein the wall wash lamp is configured to dissipate thermal energy generated by the light emitting diodes to the air flowing in the air ducts.

22. The wall wash lamp of claim 21 wherein the heat exchange structure comprises a structural section and a thin layer of ceramic material attached to the structural section, the thin layer of ceramic material having a thickness less than 100 μ

m.

23. The wall wash lamp of claim 21, further comprising a water-tight chamber enclosing the light emitting diodes.

24. The wall wash lamp of claim 21, further comprising two water-tight chambers connected by a passage, one of the chambers enclosing the light sources and the other of the chambers enclosing electronic components to control the light sources, the passage allowing signal lines to pass, the signal lines connecting the light sources to the electronic components.

25. A method comprising:

transferring thermal energy from a plurality of heat generators to multiple locations of an interior heat exchange surface of a heat exchange structure, the interior heat exchange surface being in an air duct of the heat exchange structure, the heat generators being coupled to an exterior heat exchange surface of the heat exchange structure and disposed along an elongated direction of the air duct; and

heating air in the air duct successively by transferring thermal energy from the multiple locations of the interior heat exchange surface to the air as the air flows through the air duct, enhancing air flow in the air duct by buoyancy of heated air.

26. The method of claim 25 wherein transferring thermal energy from the heat generators to the interior heat exchange surface comprises transferring thermal energy through a wall separating the exterior heat exchange surface and the interior heat exchange surface, the wall having a thickness less than 5 mm.

27. The method of claim 25, further comprising enhancing air flow in the air duct by using a fan.

28. The method of claim 25 wherein transferring heat from the heat generators to the multiple locations comprises transferring heat from electronic devices to the multiple locations.

29. A method comprising:

transferring thermal energy from a heat generator to a heat pipe;

transferring thermal energy from different portions of the heat pipe to a heat exchange structure that comprises a plurality of elongated air ducts, the different portions of the heat pipe aligned along an elongated direction of the air ducts; and

heating the air in the air ducts successively by transferring thermal energy from the different portions of the heat pipe to the air flowing in the air ducts, enhancing air flow in the air ducts by buoyancy of heated air.

30. The method of claim 29, further comprising enhancing air flow in the air ducts by using a fan.

31. A method comprising:

mounting an array of heat generators on an exterior heat exchange surface of a heat exchange structure, the heat exchange structure comprising elongated air ducts, the array of heat generators comprising groups of heat generators, each group having heat generators mounted along an elongated direction of the air ducts,

the heat exchange structure comprising interior heat exchange surfaces being in the elongated air ducts, the interior heat exchange surfaces configured to successively heat air in the air ducts by transferring heat from the array of heat generators to the air flowing in the air ducts and enhancing air flow in the air ducts due to buoyancy of heated air.

32. The method of claim 31 in which mounting the array of heat generators comprises mounting an array of light sources.

33. A method of operating a light source that comprises a plurality of light emitting devices, the method comprising:

providing electric power to the plurality of light emitting devices;

transferring thermal energy from the light emitting devices to multiple locations of an exterior heat exchange surface of a heat exchange structure, the heat exchange structure comprising an elongated air duct and an interior heat exchange surface being in the air duct;

transferring thermal energy from the multiple locations on the exterior heat exchange surface to multiple locations on the interior heat exchange surface through a wall separating the interior and exterior heat exchange surfaces; and

successively heating air in the air duct by transferring thermal energy from the multiple locations on the second heat exchange surfaces to air flowing in the air ducts, enhancing air flow in the air duct by buoyancy of heated air.

34. The method of claim 33, further comprising using a fan to enhance air flow in the air duct.