Cooling device

1. A cooling device comprising:

a magnetocaloric unit disposed between a heat sink and a heat load, wherein the magnetocaloric unit includes a recess formed in a surface of the magnetocaloric unit that faces the heat load;

an electromagnet operably connected with the magnetocaloric unit;

at least one refrigerant storage included in the magnetocaloric unit; and

a first device at least partially disposed in the recess and disposed between the magnetocaloric unit and the heat load, wherein the first device is configured to selectively couple or decouple the surface of the magnetocaloric unit that faces the heat load directly to or from a surface of the heat load that faces the magnetocaloric unit such that the surface of the magnetocaloric unit that faces the heat load selectively contacts the surface of the heat load that faces the magnetocaloric unit,

wherein the magnetocaloric unit is cooled down by using an evaporation heat of a refrigerant in the refrigerant storage.

2. The cooling device of claim 1 , wherein the electromagnet is configured to apply a magnetic field to the magnetocaloric unit and to heat the magnetocaloric unit up to a boiling point of the refrigerant.

3. The cooling device of claim 1 , wherein the first device comprises at least one first switch.

4. The cooling device of claim 3 , further comprising:

at least one second switch disposed between the magnetocaloric unit and the heat sink.

5. The cooling device of claim 3 , wherein the at least one first switch comprises a thermostat switch.

6. The cooling device of claim 4 , wherein the magnetocaloric unit further includes at least one recess formed in a surface of the magnetocaloric unit that faces the heat sink and wherein the at least one second switch is at least partially disposed in the at least one recess formed in the surface of the magnetocaloric unit that faces the heat sink.

7. The cooling device of claim 6 , wherein the magnetocaloric unit further includes at least one switch holder configured to hold the at least one second switch in the at least one recess formed in the surface of the magnetocaloric unit that faces the heat sink.

8. The cooling device of claim 1 , wherein the refrigerant includes perfluorocarbon (PFC).

9. The cooling device of claim 8 , wherein a boiling point of the refrigerant ranges from about 30° C. to about 60° C. at about 1 atm.

10. The cooling device of claim 8 , wherein the magnetocaloric unit includes at least one of Gadolinium (Gd) and MnFe (P, As) alloys.

11. The cooling device of claim 8 , wherein the magnetocaloric unit has at least one embossed pattern on at least one surface facing the heat load and/or the heat sink.

12. A magnetocaloric device comprising:

a magnetocaloric material that includes a recess formed in a surface of the magnetocaloric material that faces a heat load;

a first device at least partially disposed in the recess and disposed between the magnetocaloric material and the heat load, wherein the first device is configured to selectively couple or decouple the surface of the magnetocaloric material that faces the heat load directly to or from a surface of the heat load that faces the magnetocaloric material such that the surface of the magnetocaloric material that faces the heat load selectively contacts the surface of the heat load that faces the magnetocaloric material; and

at least one refrigerant storage including a refrigerant, the at least one refrigerant storage surrounded by the magnetocaloric material.

13. The magnetocaloric device of claim 12 , wherein the at least one refrigerant storage has at least one of tube shape, hexahedron shape and cylinder shape.

14. The magnetocaloric device of claim 12 , wherein the magnetocaloric unit has at least one embossed pattern on at least one surface thereof.

15. The magnetocaloric device of claim 12 , wherein the refrigerant includes perfluorocarbon (PFC).

16. The magnetocaloric device of claim 15 , wherein a boiling point of the refrigerant ranges from about 30° C. to about 60° C. at about 1 atm.

17. A method for controlling a cooling device in which a magnetocaloric unit is placed between a heat sink and a heat load, the method comprising:

absorbing heat in the heat load by the magnetocaloric unit;

isolating the magnetocaloric unit from the heat load by at least one first device at least partially disposed in a recess formed in a surface of the magnetocaloric unit that faces the heat load, including operating the at least one first device to selectively decouple the surface of the magnetocaloric unit that faces the heat load from contact with a surface of the heat load that faces the magnetocaloric unit;

applying a magnetic field to the magnetocaloric unit; and

cooling down the magnetocaloric unit by an evaporation heat of a refrigerant in at least one refrigerant storage included in the magnetocaloric unit.

18. The method of claim 17 , further comprising:

making at least a portion of the magnetocaloric unit in contact with the heat sink by at least one second switch disposed between the magnetocaloric unit and the heat sink at a first temperature of the magnetocaloric unit.

19. The method of claim 17 , wherein the refrigerant includes perfluorocarbon (PFC).

20. The method of claim 17 , further comprising:

maintaining the isolating if a temperature of the magnetocaloric unit is higher than a second temperature.