Vapor chamber heat flux rectifier and thermal switch

Patent metadata

Field	Value
Publication number	US-10066876-B2
Application number	US-201615261063-A
Country	US
Kind code	B2
Filing date	Sep 9, 2016
Priority date	Sep 9, 2016
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

Embodiments of an evaporator chamber heat flux rectifier and thermal switch are provided. Some embodiments include an evaporator layer with a first thermally conductive surface, a wicking structure for facilitating evaporation of a fluid in the vapor chamber heat flux rectifier, and a condenser layer that includes a second thermally conductive surface. Some embodiments include a middle layer, where when heat is applied to the first thermally conductive surface, the vapor chamber heat flux rectifier operates as a thermal conductor. Some embodiments that operate as a thermal switch include a non-condensable gas reservoir that is coupled to the condenser layer. The non-condensable gas reservoir may store a non-condensable gas when a threshold heat flux is applied to the evaporator layer. The non-condensable gas provides thermal insulation between the evaporator layer and the condenser layer when the threshold heat flux is not applied to the evaporator layer.

First claim

What is claimed is:

1. A vapor chamber heat flux rectifier comprising:
an evaporator layer that includes a first thermally conductive surface and an evaporator wicking structure for facilitating evaporation of a fluid in the vapor chamber heat flux rectifier;
a condenser layer that includes a second thermally conductive surface and a condenser wicking structure for facilitating condensation of the fluid in the vapor chamber heat flux rectifier; and
a middle layer that includes a coupling wicking structure that is coupled to the evaporator wicking structure, wherein when heat is applied to the first thermally conductive surface, the vapor chamber heat flux rectifier operates as a thermal conductor, wherein when heat is applied to the second thermally conductive surface, the middle layer thermally decouples the evaporator layer and the condenser layer, thereby causing the vapor chamber heat flux rectifier to operate as a thermal insulator.

2. The vapor chamber heat flux rectifier of claim 1 , further comprising a solid pillar for connecting the evaporator layer with the condenser layer.

3. The vapor chamber heat flux rectifier of claim 1 , wherein the condenser wicking structure comprises at least one of the following: a grooved coarse wicking structure and a coarse wick with high porosity and high thermal conductivity.

4. The vapor chamber heat flux rectifier of claim 1 , further comprising a sealing material, wherein the sealing material includes a low thermal conductivity.

5. The vapor chamber heat flux rectifier of claim 1 , wherein the coupling wicking structure is not coupled to the condenser layer in a first state, and wherein in response to a threshold heat flux being applied to the evaporator layer, the coupling wicking structure expands to couple with the condenser layer, thereby creating a condensation path for the fluid to reach to the evaporator layer.

6. The vapor chamber heat flux rectifier of claim 1 , wherein the coupling wicking structure comprises a flexible piece and a supporting piece with a large coefficient of thermal expansion relative to the flexible piece, wherein the coupling wicking structure is not coupled to the condenser layer in a first state, and wherein in response to a threshold heat flux being applied to the evaporator layer, the supporting piece expands, causing the coupling wicking structure to couple with the condenser wicking structure, thereby creating a condensation path for the fluid to reach the evaporator layer.

7. The vapor chamber heat flux rectifier of claim 1 , further comprising a non-condensable gas reservoir that is coupled to the condenser layer to operate as a thermal switch, wherein the non-condensable gas reservoir stores a non-condensable gas when a threshold heat flux is applied to the evaporator layer and wherein the non-condensable gas provides thermal insulation between the evaporator layer and the condenser layer when the threshold heat flux is not applied to the evaporator layer.

8. The vapor chamber heat flux rectifier of claim 1 , further comprising a non-condensable gas and operating as a thermal switch, wherein in response to receiving a threshold heat flux, saturation pressure of the fluid exceeds the ambient pressure within the vapor chamber heat flux rectifier and liquid within the vapor chamber heat flux rectifier boils, thereby transferring heat from the evaporator layer to the condenser layer and then out of the vapor chamber heat flux rectifier.

9. A vapor chamber heat flux rectifier comprising:
an evaporator layer that includes a first thermally conductive surface and an evaporator wicking structure for facilitating evaporation of a fluid in the vapor chamber heat flux rectifier;
a condenser layer that includes a second thermally conductive surface and a condenser wicking structure for facilitating condensation of the fluid in the vapor chamber heat flux rectifier;
a middle layer that includes a coupling wicking structure that is coupled to the evaporator wicking structure; and
non-condensable gas in the vapor chamber heat flux rectifier, wherein in response to receiving a threshold heat flux, a saturation pressure of the fluid exceeds an ambient pressure within the vapor chamber heat flux rectifier and fluid boiling facilitates transferring of heat from the evaporator layer to the condenser layer and out of the vapor chamber heat flux rectifier, thus operating as a thermal conductor, and wherein if an amount of heat that is lower than the threshold heat flux is applied to the vapor chamber heat flux rectifier, the vapor chamber heat flux rectifier operates as a thermal insulator.

10. The vapor chamber heat flux rectifier of claim 9 , further comprising a solid pillar for connecting the evaporator layer with the condenser layer.

11. The vapor chamber heat flux rectifier of claim 10 , wherein the condenser wicking structure comprises at least one of the following: a grooved coarse wicking structure and a thin coarse wick with high porosity and high thermal conductivity.

12. The vapor chamber heat flux rectifier of claim 9 , further comprising a sealing material, wherein the sealing material includes a low thermal conductivity.

13. The vapor chamber heat flux rectifier of claim 9 , wherein the coupling wicking structure is not coupled to the condenser layer in a first state, and wherein in response to the threshold heat flux being applied to the evaporator layer, the coupling wicking structure expands to couple with the condenser layer, thereby creating a condensation path for the fluid to reach to the evaporator layer.

14. The vapor chamber heat flux rectifier of claim 9 , wherein the coupling wicking structure comprises a flexible piece and a supporting piece with a large coefficient of thermal expansion relative to the flexible piece, wherein the coupling wicking structure is not coupled to the condenser layer in a first state, and wherein in response to the threshold heat flux being applied to the evaporator layer, the supporting piece expands, causing the coupling wicking structure to couple with the condenser wicking structure, thereby creating a condensation path for the fluid to reach the evaporator layer.

15. The vapor chamber heat flux rectifier of claim 9 , further comprising a non-condensable gas reservoir that is coupled to the condenser layer to operate as a thermal switch, wherein the non-condensable gas reservoir stores the non-condensable gas when the threshold heat flux is applied to the evaporator layer and wherein the non-condensable gas provides thermal insulation between the evaporator layer and the condenser layer when the amount of heat is lower than the threshold heat flux.

16. A vapor chamber heat flux rectifier comprising:
an evaporator layer that includes a first thermally conductive surface and an evaporator wicking structure for facilitating evaporation of a fluid in the vapor chamber heat flux rectifier;
a condenser layer that includes a second thermally conductive surface and a condenser wicking structure for facilitating condensation of the fluid in the vapor chamber heat flux rectifier; and
a middle layer that includes a coupling wicking structure that is coupled to the evaporator wicking structure but not to the condenser wicking structure until a threshold heat flux is applied to the evaporator layer, wherein when the threshold heat flux is applied to the first thermally conductive surface, the coupling wicking structure couples with the condenser wicking structure to provide a condensation path for the fluid, thereby operating a thermal conductor, wherein when heat is applied to the vapor chamber heat

Assignees

• Toyota Eng & Mfg North America
• Univ Leland Stanford Junior

Inventors

• Zhou Feng
• Dede Ercan M
• Asheghi Mehdi
• Palko James W
• Goodson Kenneth E

Classifications

• H10W40/73

  for cooling by change of state · CPC title

• F28D15/046

  characterised by the material or the construction of the capillary structure · CPC title

• F28F2225/04

  for conduits · CPC title

• F28F2270/00

  Thermal insulation; Thermal decoupling · CPC title

• F28F2013/008

  Variable conductance materials; Thermal switches · CPC title