MAGNETOCALORIC MODULE FOR MAGNETIC REFRIGERATION APPARATUS
A magnetocaloric module for a magnetic refrigeration apparatus includes: a bed having an inner surface; a magnetocaloric material filled in the bed; and an insulating layer formed over the inner surface, isolating the magnetocaloric material from the bed. With the use of the insulating layer, thermal conduction between the magnetocaloric material and the bed can be reduced and Galvanic corrosion which may occur to the bed can be prevented. Also, a temperature gradient of the magnetocaloric module may be further extended.
1. Field of the Invention
The present invention relates to magnetic refrigeration techniques, and in particularly to a magnetocaloric module for a magnetic refrigeration apparatus.
2. Description of the Related Art
At present, almost all refrigeration technologies applied in an environment of room temperature, which is closely associated with the daily lives of humans, for example, a refrigerator, a freezing chamber, a room heating/cooling system, and the like, mostly employ a gas compression/expansion cycle. However, the refrigeration technologies based on the gas compression/expansion cycle have a serious problem of environmental destruction due to specific freon gas discharged into the environment. Further, as to an alternative freon gas, its adverse affects on the environment are also of concern.
Thus, expectations have been raised for magnetic refrigeration technologies using a magnetocaloric effect as one of the environmentally conscious and effective refrigeration technology. Accordingly, the speed of research and development for magnetic refrigeration technologies for room temperature environments have been accelerated.
A conventional magnetic refrigeration apparatus is disclosed in U. S. Pat. App. Pub. No. 2010/0058775. As shown in
The magnetic refrigeration apparatus shown in
During operation of the magnetic refrigeration apparatus shown in
Thereafter, the permanent magnet 14 is moved from the position confronting the AMR bed 10, and the magnetic field applied to the magnetic material 12 is removed. The magnetic material 12 absorbs heat by removing the magnetic field. Accordingly, the liquid refrigerant is circulated by the operations of the refrigerant pump 50 and the switching means 40 in a direction from the AMR bed 10 to the low temperature side heat exchanging unit 21. A cooler temperature is transported to the low temperature side heat exchanging unit 21 by the liquid refrigerant cooled by the heat absorption of the magnetic material 12.
A temperature gradient is formed in the magnetic material 12 in the AMR bed 10 by repeating the application and removal of the magnetic field to and from the magnetic material 12 in the AMR bed 10 by repeating the movement of the permanent magnet 14. Then, the low temperature side heat exchanging unit 21 is continuously cooled by moving the liquid refrigerant in synchronization with the application and the removal of the magnetic field.
However, due to physical connections between the magnetic material 12 and the AMR bed 10, and different metal materials of the magnetic material 12 and the AMR bed 10, thermal dissipation and Galvanic corrosion may be caused to the AMR beds 10, thereby affecting thermal and physical reliabilities of the magnetic refrigeration apparatus comprising the AMR bed 10.
BRIEF SUMMARY OF THE INVENTIONAccordingly, a magnetocaloric module for a magnetic refrigeration apparatus with reduced thermal dissipation and Galvanic corrosion is provided.
An exemplary magnetocaloric module for a magnetic refrigeration apparatus comprises a bed having an inner surface; a magnetocaloric material filled in the bed; and an insulating layer formed over the inner surface, isolating the magnetocaloric material from the bed. With the use of the insulating layer, thermal conduction between the magnetocaloric material and the bed can be reduced and Galvanic corrosion which may occur to the bed can be prevented. Also, a temperature gradient of the magnetocaloric module may be further extended.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
In
In the magnetocaloric module A shown in
In
In
In
In
In
In the various embodiments as disclosed in
Note that for all embodiments mentioned above, additives for enhancing performance could be added into the fluid pathway (e.g. a fluid pathway between the two ends 150 and 160 of the bed 100), such as a dispersant, an anti-corrosion agent, an antifreeze agent, or a drag-reduction agent. The dispersant (or dispersing agent, or plasticizer, or super-plasticizer as Wikipedia™ disclosed) is either a non-surface active polymer or a surface-active substance added to a suspension, usually a colloid, to improve the separation of particles and to prevent settling or clumping. Dispersants consist normally of one or more surfactants, but may also be gases. The anti-corrosion agent (or corrosion inhibitor) is used for preventing magnetocaloric material (particles) from corrosion or erosion after cycles of fluid passing thereby. The antifreeze agent (or anti-frozen agent) is used to prevent the working fluid from freezing in some cooling processes. The drag-reduction agent (or flow improver as Wikipedia™ disclosed) is a long chain polymer chemical that is used in crude oil, refined products or non-potable water pipelines. It is injected in small amounts (parts per million) and is used to reduce the frictional pressure which drops along the pipeline's length.
While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
Claims
1. A magnetocaloric module for a magnetic refrigeration apparatus, comprising:
- a bed having an inner surface;
- a magnetocaloric material filled in the bed; and
- an insulating layer formed over the inner surface, isolating the magnetocaloric material from the bed.
2. The magnetocaloric module as claimed in claim 1, wherein the insulating layer entirely covers the inner surface of the bed and the magnetocaloric material fails to contact the inner surface of the bed.
3. The magnetocaloric module as claimed in claim 2, wherein the insulating layer is a single layer.
4. The magnetocaloric module as claimed in claim 2, wherein the insulating layer is a composite layer comprising a first insulating sub-layer and a second insulating sub-layer, and the first insulating sub-layer and the second insulating sub-layer respectively covers a different portion of the inner surface of the bed.
5. The magnetocaloric module as claimed in claim 2, wherein the insulating layer is a composite layer comprising a first insulating layer and a second insulating layer, and the first insulating layer entirely covers the inner surface of the bed and the second insulating layer entirely covers a surface of the first insulating layer.
6. The magnetocaloric module as claimed in claim 1, wherein the insulating layer covers most of the inner surface of the bed and a portion of about 0-50% of the inner surface of the bed is exposed such that the magnetocaloric material partially contacts the inner surface of the bed.
7. The magnetocaloric module as claimed in claim 1, wherein the insulating layer covers most of the inner surface of the bed and a portion of about 10-45% of the inner surface of the bed is exposed such that the magnetocaloric material partially contacts the inner surface of the bed.
8. The magnetocaloric module as claimed in claim 6, wherein the insulating layer is a single layer.
9. The magnetocaloric module as claimed in claim 6, wherein the insulating layer is a composite layer comprising a first insulating sub-layer and a second insulating sub-layer, and one of the first insulating sub-layer and the second insulating sub-layer exposes the portion of the inner surface of the bed.
10. The magnetocaloric module as claimed in claim 6, wherein the insulating layer is a composite layer comprising a first insulating layer and a second insulating layer, and the first insulating layer partially covers the inner surface of the bed and the second insulating layer entirely covers a surface of the first insulating layer.
11. The magnetocaloric module as claimed in claim 1, wherein the bed comprises magnetic permeable materials.
12. The magnetocaloric module as claimed in claim 11, wherein the magnetic permeable materials comprise steels or irons.
13. The magnetocaloric module as claimed in claim 1, wherein the bed is formed with a shape selected from a group consisting of a rectangular shape, cylindrical shape, and polygonal shape.
14. The magnetocaloric module as claimed in claim 1, wherein the insulating layer comprise foamed materials, silica gel, rubber, or gas-filled foamed materials, or latexes.
15. The magnetocaloric module as claimed in claim 1, wherein the magnetocaloric material comprises FeRh, Gd5Si2Ge2, Gd5(Si1-xGex)4, RCo2, La(Fe13-xSix), MnAs1-xSbx, MnFe(P, As), MnFe(P, Si), Co(S1-xSex)2, NiMnSn, MnCoGeB, or R1-xMxMnO3, (where R=lanthanide, M=Ca, Sr and Ba).
16. The magnetocaloric module as claimed in claim 1, wherein the magnetocaloric material is formed in a configuration selected from a group consisting of a particle-like, mesh-like, flake-like, tube-like, rod-like, sheet-like and honeycomb-like configuration.
Type: Application
Filed: Feb 1, 2012
Publication Date: Aug 1, 2013
Inventors: Min-Chia Wang (Taoyuan Hsien), Sheng-Fan Hsieh (Taoyuan Hsien), Tiao-Yuan Wu (Taoyuan Hsien)
Application Number: 13/363,940
International Classification: F25B 21/00 (20060101);