Variable temperature magneto-caloric thermal diode assembly

Patent metadata

Field	Value
Publication number	US-10557649-B2
Application number	US-201815955843-A
Country	US
Kind code	B2
Filing date	Apr 18, 2018
Priority date	Apr 18, 2018
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

A magneto-caloric thermal diode assembly includes a magneto-caloric cylinder with a plurality of magneto-caloric stages. Each of the plurality of magneto-caloric stages has a respective Currie temperature. The magneto-caloric cylinder has a length along an axial direction. The plurality of magneto-caloric stages is distributed along the length of the magneto-caloric cylinder. A plurality of thermal stages also has a length along the axial direction. The length of the plurality of thermal stages is less than the length of the magneto-caloric cylinder. The magneto-caloric cylinder is received within the plurality of thermal stages such that the magneto-caloric cylinder is movable along the axial direction relative to the plurality of thermal stages.

First claim

What is claimed is:

1. A magneto-caloric thermal diode assembly, comprising:
a magneto-caloric cylinder comprising a plurality of magneto-caloric stages, each of the plurality of magneto-caloric stages having a respective Currie temperature, the magneto-caloric cylinder having a length along an axial direction, the plurality of magneto-caloric stages distributed along the length of the magneto-caloric cylinder; and
a plurality of thermal stages stacked along the axial direction between a cold side and a hot side, each of the plurality of thermal stages comprises a plurality of magnets and a non-magnetic ring, the plurality of magnets distributed along a circumferential direction within the non-magnetic ring in each of the plurality of thermal stages, the plurality of thermal stages having a length along the axial direction, the length of the plurality of thermal stages being less than the length of the magneto-caloric cylinder;
wherein the plurality of thermal stages and the magneto-caloric cylinder are configured for relative rotation between the plurality of thermal stages and the magneto-caloric cylinder, and
wherein the magneto-caloric cylinder is received within the plurality of thermal stages such that the magneto-caloric cylinder is movable along the axial direction relative to the plurality of thermal stages.

2. The magneto-caloric thermal diode assembly of claim 1 , wherein:
a cold side thermal stage of the plurality of thermal stages is positioned at the cold side;
a hot side thermal stage of the plurality of thermal stages is positioned at the hot side;
each of the plurality of thermal stages between the cold side thermal stage and the hot side thermal stage is positioned between a respective pair of the plurality of thermal stages along the axial direction;
one of the respective pair of the plurality of thermal stages is positioned closer to the cold side along the axial direction;
the other of the respective pair of the plurality of thermal stages is positioned closer to the hot side along the axial direction;
the plurality of magnets of each of the plurality of thermal stages between the cold side thermal stage and the hot side thermal stage is spaced from the non-magnetic ring of the one of the respective pair of the plurality of thermal stages along the axial direction; and
the plurality of magnets of each of the plurality of thermal stages between the cold side thermal stage and the hot side thermal stage is in conductive thermal contact with the non-magnetic ring of the other of the respective pair of the plurality of thermal stages.

3. The magneto-caloric thermal diode assembly of claim 2 , wherein the plurality of magnets of each of the plurality of thermal stages between the cold side thermal stage and the hot side thermal stage is spaced from the non-magnetic ring of the one of the respective pair of the plurality of thermal stages along the axial direction by insulation.

4. The magneto-caloric thermal diode assembly of claim 1 , further comprising a heat exchanger positioned at the cold side.

5. The magneto-caloric thermal diode assembly of claim 1 , wherein the plurality of magnets is spaced from the non-magnetic ring along the radial direction and the circumferential direction within each of the plurality of thermal stages.

6. The magneto-caloric thermal diode assembly of claim 5 , wherein each of the plurality of thermal stages further comprises insulation positioned between the plurality of magnets and the non-magnetic ring along the radial direction and the circumferential direction.

7. The magneto-caloric thermal diode assembly of claim 1 , wherein the non-magnetic ring is an aluminum ring.

8. The magneto-caloric thermal diode assembly of claim 1 , wherein the plurality of magnets are uniformly spaced apart along the circumferential direction within the non-magnetic ring in each of the plurality of thermal stages.

9. The magneto-caloric thermal diode assembly of claim 8 , wherein each of the plurality of thermal stages comprises no less than ten magnets.

10. The magneto-caloric thermal diode assembly of claim 1 , wherein the plurality of thermal stages and the magneto-caloric cylinder are configured for relative rotation about an axis that is parallel to the axial direction.

11. The magneto-caloric thermal diode assembly of claim 1 , wherein the plurality of magnets and the non-magnetic ring of each of the plurality of thermal stages collectively define a cylindrical slot, the magneto-caloric cylinder positioned within the cylindrical slot.

12. The magneto-caloric thermal diode assembly of claim 11 , wherein the cylindrical slot has a width along a radial direction, the magneto-caloric cylinder having a thickness along the radial direction within the cylindrical slot, the width of the cylindrical slot being about one hundredth of an inch greater than the thickness of the magneto-caloric cylinder.

13. The magneto-caloric thermal diode assembly of claim 1 , wherein plurality of thermal stages comprises no less than eight thermal stages.

14. The magneto-caloric thermal diode assembly of claim 1 , wherein:
a cold side thermal stage of the plurality of thermal stages is positioned at the cold side;
a hot side thermal stage of the plurality of thermal stages is positioned at the hot side; and
the length of the hot side thermal stage is less than the length of the cold side thermal stage.

15. The magneto-caloric thermal diode assembly of claim 1 , wherein the respective Currie temperature of each of the plurality of magneto-caloric stages is selected such that a total Currie temperature span of the plurality of magneto-caloric stages is about eighty degrees Celsius along the length of the magneto-caloric cylinder.

16. The magneto-caloric thermal diode assembly of claim 15 , wherein only a portion of the magneto-caloric cylinder is received within the plurality of thermal stages such that an operating Currie temperature span of the plurality of magneto-caloric stages is about fifty degrees Celsius.

17. The magneto-caloric thermal diode assembly of claim 1 , wherein a minimum Currie temperature of the plurality of magneto-caloric stages is about negative thirty degrees Celsius, and a maximum Currie temperature of the plurality of magneto-caloric stages is about thirty-five degrees Celsius.

18. The magneto-caloric thermal diode assembly of claim 1 , further comprising a controller in operative communication with a linear actuator and a temperature sensor, the linear actuator coupled to the magneto-caloric cylinder, the linear actuator operable to move the magneto-caloric cylinder along the axial direction relative to the plurality of thermal stages, the controller configured to operate the linear actuator in response to a temperature measurement from the temperature sensor.

19. A magneto-caloric thermal diode assembly, comprising:
a magneto-caloric cylinder comprising a plurality of magneto-caloric stages, each of the plurality of magneto-caloric stages having a respective Currie temperature, the magneto-caloric cylinder having a length along an axial direction, the plurality of magneto-caloric stages distributed along the length of the magneto-caloric cylinder; and
a plurality of thermal stages stacked along the axial direction between a cold side and a hot side, each of the plurality of thermal stages comprises a plurality of non-magnetic blocks and a magnetic ring, the plurality of non-magnetic blocks distributed along a circumferential direction within the magnetic ring in each of the plurality of thermal sta

Assignees

• Haier Us Appliance Solutions Inc

Inventors

• Schroeder Michael Goodman

Classifications

• F25D11/02

  with cooling compartments at different temperatures · CPC title

• F28D9/0012

  the apparatus having an annular form · CPC title

• F28D7/106

  consisting of two coaxial conduits or modules of two coaxial conduits · CPC title

• H01F1/012

  adapted for magnetic entropy change by magnetocaloric effect, e.g. used as magnetic refrigerating material (refrigeration systems using magnetic effects F25B21/00) · CPC title

• F25B2321/0022

  with a rotating or otherwise moving magnet · CPC title