Heat-absorbing device with phase-change material

Patent metadata

Field	Value
Publication number	US-9291406-B2
Application number	US-201213984955-A
Country	US
Kind code	B2
Filing date	Feb 9, 2012
Priority date	Feb 11, 2011
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A heat absorbing device including a structure including plural individual cells delimited by an envelope made of a material that has good thermal conductivity and includes at least one phase-change material, the cells being stacked on top of one another from an end surface so that the structure extends in a direction of thermal flux, the flux being made up of two notable periodic thermal events, the structure including two different sizes of cells. The sizes of the cells are determined as a function of frequency of the thermal events of the thermal flux and a distribution of a number of cells of each size is determined as a function of amplitudes of each event.

First claim

The invention claimed is:

1. A heat absorbing device comprising a structure comprising:
a plurality of individual cells, each cell being delimited by an envelope made of a material that has good thermal conductivity and includes at least one phase-change material;
a first end surface configured to be in contact with a surface emitting a thermal flux to be absorbed, the thermal flux being made up of at least two thermal events of different amplitudes and different frequencies, the cells being stacked on top of one another from the first end surface so that the structure extends at least in a direction of the thermal flux, the cells being in contact with each other by their envelope;
at least one first size of cell and one second size of cell, a quantity of phase-change material in each cell being proportional to its size;
wherein the first size of cell is determined as a function of frequency of the first event and the second size of cell is determined as a function of frequency of the second event;
wherein a distribution between a number of cells of first size and a number of cells of second size is determined as a function of amplitudes of the first and second events; and
wherein the first size of cell and the second size of cell increase when the frequency of the first event and the frequency of the second event respectively reduce, and wherein the number of cells of first size and the number of cells of second size increase when the amplitude of the first event and the amplitude of the second event respectively increase.

2. A heat absorbing device according to claim 1 , wherein the frequency of the second event is less than that of the first event, the second size of cell is greater than the first size of cell, and wherein the cells of first size are situated on a side of the first end surface.

3. A heat absorbing device according to claim 1 , wherein the size of the cells increases in the direction of the thermal flux from the first end surface.

4. A heat absorbing device according to claim 1 , wherein the cells are interconnected to enable passage of the materials with change of phase from one cell to a next.

5. A heat absorbing device according to claim 4 , wherein the cells are interconnected in the direction of the thermal flux.

6. A heat absorbing device according to claim 1 , comprising at least one favoured heat conduction path extending from the first end surface in the direction of the thermal flux between the cells.

7. A heat absorbing device according to claim 6 , comprising plural favoured conduction paths distributed regularly in the structure.

8. A heat absorbing device according to claim 6 , wherein a size of the at least one favoured conduction path represents from 20% to 100% of the size of the cell.

9. A heat absorbing device according to claim 6 , wherein the at least one favoured conduction path is formed by a portion of heat conducting material situated between the cells and extending in the direction of the thermal flux.

10. A heat absorbing device according to claim 9 , wherein the portion of heat conducting material is of a same material as that of walls of the cells.

11. A heat absorbing device according to claim 10 , wherein the portion of heat conducting material and the envelopes of the cells in contact with the portion are all in one piece.

12. A heat absorbing device according to claim 1 , further comprising an extracting device of latent heat stored in the phase-change material.

13. A heat absorbing device according to claim 12 , wherein the extracting device comprises at least one channel between the cells in which a coolant circulates.

14. A heat absorbing device according to claim 13 , wherein circulation of the coolant is controlled as a function of occurrence of a thermal event.

15. A heat absorbing device according to claim 1 , further comprising a thermal insulator for insulating lateral edges of stacked cells.

16. A heat absorbing device according to claim 1 , the at least one phase-change material implemented having a phase change temperature between 50° C. and 350° C.

17. A heat absorbing device according to claim 1 , comprising three sizes of cells of parallelepiped shape, the cells of each size being arranged in a layer, the cells being interconnected between each layer.

18. A method of forming a heat absorbing device according to claim 1 configured to absorb a thermal flux of period emitted by a heat source, comprising:
a) calculating from a function representative of the thermal flux of period of a limited development of order n of periodic functions, each corresponding to an individual heat source of frequency;
b) selecting periodic functions of which the sum of the amplitudes is greater than a given percentage of the maximum amplitude of the thermal flux;
c) determining the size of the cells as a function of the frequencies of the selected functions, the size of the cells increasing when the frequency of the selected functions decreases;
d) determining the distribution of the number of cells of each size as a function of the amplitude of the selected functions, the number of cells of each size increasing when the amplitude of the selected functions increases;
e) forming a device provided with cells of which the size and the number correspond to those determined during c) and d).

19. A method according to claim 18 , the given percentage being between 60% to 98%.

Assignees

• Gavillet Jerome
• Commissariat à l'énergie atomique et aux énergies alternatives

Inventors

• Gavillet Jerome

Classifications

• H10W40/73 Primary

  for cooling by change of state · CPC title

• F28D20/021

  the latent heat storage material and the heat-exchanging means being enclosed in one container (F28D20/023 - F28D20/028 take precedence) · CPC title

• F28D20/023 Primary

  the latent heat storage material being enclosed in granular particles or dispersed in a porous, fibrous or cellular structure · CPC title

• H01L2924/00

  Electricity · mapped topic

• B23P15/26

  heat exchangers {or the like (making heat exchangers by methods covered by other subclasses B21D53/02)} · CPC title