US20050022979A1

US20050022979A1 - Apparatus for heat dissipation and dissipation fluid therein

Info

Publication number: US20050022979A1
Application number: US10/869,947
Authority: US
Inventors: Chei-Chiang Chen; Hsin-Tang Chien
Original assignee: Chei-Chiang Chen
Current assignee: CHEI-CHIANG CHEN; CHEI CHIANG CHEN
Priority date: 2002-12-09
Filing date: 2004-06-18
Publication date: 2005-02-03
Also published as: TW593954B; TW200409895A

Abstract

An apparatus for heat dissipation is disclosed, which has a sealed container having a closed cavity; and a dissipation fluid comprising plural nanoparticles and a solvent. The dissipation fluid is set in and is able to flow through said sealed closed cavity of said container. A dissipation fluid used in the apparatus illustrated above is also disclosed.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to an apparatus for heat dissipation and heat dissipation fluid thereof, more particularly, to an apparatus for heat dissipation by nanoparticles and heat dissipation fluid containing nanoparticles.
2. Description of Related Art
It is known that electronic devices always generate some heats as they are operating in a standard condition. If the heat generates by the electronic devices or the surrounding environments cannot be dissipated effectively, most of the electronic devices will function abnormally. In most cases, at least a heat dissipating element is employed to keep the temperature of the electronic device well controlled and further prevent the possibility of unwanted interruptions owing to overheat of the electronic device.
Currently, there are various types of techniques or heat dissipating elements for preventing overheat of electronic devices internally or externally. For example, conventional heat pipes with capillaries are widely used for dissipating heat from electronic devices effectively. However, some drawbacks of these kinds of heat pipes are still need to be overcome with.
For instance, when heat pipes with capillaries are heated, bubbles are generated within the fluid inside the heat pipes. In most cases, the induced bubbles aggregate on the inside surface of the heat pipe. These aggregated bubbles will increase the thermal resistance to heat dissipation and also reduce the heat transfer efficiency of the heat pipe, these types of problems are amplified especially when the size of the bubbles are large. Obviously the efficiency of heat transfer decreases with increase in the amount of large bubbles, since the fluid and the particles flowing inside the heat pipes used for heat exchanging are blocked by the induced bubbles. Therefore, it is desirable to provide an improved heat dissipation apparatus to mitigate and/or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

The object of the present invention is to provide an apparatus for heat dissipation and more particularly to an apparatus which can reduce the flow-blockage effect of the induced bubbles and increase the efficiency of heat transfer by the assistance of fluent flowing of tiny nanoparticles in a closed or sealed container.
Other object of the present invention is to provide a dissipation fluid for dissipating heat to reduce the flow-blockage effect of induced bubbles and increase the efficiency of heat transfer by the assistance of fluent flowing of tiny nanoparticles in a closed or sealed container.
Since the size of the nanoparticles is microscopic, the nanoparticles can flow fluently inside a sealed heat pipe with capillaries within. Theoretically, the flowing nanoparticles can even burst or disturb part of the induced bubbles through collision, thereby further reduce in the number of the induced bubbles. Moreover, the nanoparticles can also increase the capillary effect because of their small size.
To achieve the object, the apparatus for heat dissipation of the present invention includes: a sealed container having a closed cavity; and a dissipation fluid comprising plural nanoparticles and a solvent; wherein said dissipation fluid is located in and is able to flow in said sealed closed cavity of said container.
The dissipation fluid of the present invention is also disclosed. The dissipation fluid for dissipating heat in a container having a closed cavity, includes: a solvent; and plural nanoparticles dispersed in said solvent; wherein said dissipation fluid is located in and is able to flow in said sealed closed cavity of said container.
The sealed or closed containers of the present invention can be any conventional sealed or closed containers. Preferably, the sealed or closed container of the present invention is a heat pipe with capillary within. The solvent of the present invention can be any conventional solvent for heat transfer. Preferably, the solvents used for dissipating heat of the present invention are water or liquids.
The fluid of the present invention can be any fluid containing nanoparticles and conventional heat dissipating solvents. The concentration of the nanoparticles is not limited. Preferably, the concentration of the nanoparticles of the dissipating fluid of the present invention ranges from 0.001% to 10%. The nanoparticles of the present invention can be any conventional thermal conductive nanoparticles. Preferably, the nanoparticles of the present invention are metal nanoparticles or metal oxide nanoparticles. Most preferably, the nanoparticles of the present invention are gold, silver, copper, platinum, aluminum, titanium oxide, iron oxide, or fullerenes. The diameter of the nanoparticles can be any length that the nanoparticles can flow fluently and won't be blockade by the induced bubbles. Hence, even though bubbles are generated on the surface of the container, the nanoparticles can still flow through fluently because they are relatively small compare to the size that of the bubbles. The diameter of the nanoparticles of the present invention is preferably between 1 nm to 500 nm. The dissipation fluid of the present invention can optionally further includes other additives to increase the thermal efficiency or functions of the dissipation fluid Preferably, a dispersant is included in the dissipation fluid of the present invention which prevents the aggregation of the nanoparticles. The dispersant can be any conventional dispersant. Preferably, the dispersant of the present invention is tetraethylamine or salts thereof. The form of the sealed container is not limited. Preferably, the form of the container of the present invention is in a pipe shape. The sealed container of the present invention can be any conventional container but not limited to a heat pipe. Moreover, the position for subjecting heat source on the container of the present invention is not limited. The position is preferred to be the position on any end of the container or on the center part of the container. Of course, the portion for dissipating heat or transferring heat out of the container of the present invention is not limited. The portion for dissipating heat or transferring heat out of the container of the present invention is preferred to be on one end of the container or on the center part of the container.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an example of the application of the heat pipe of the present invention.
FIG. 2 is a cross-section view of the heat pipe of the present invention.
FIG. 3 is a prospective view of one of the embodiment of the heat pipe of the present invention.
FIG. 4 is a prospective view of the bottom-plate of the mounting-base illustrated above.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIG. 1, there is shown an example of application of the heat pipes of the present invention. Two of the heat pipes 1 (or sealed containers) are located between and connects to a heat source 6 and a heat-dissipation fin 7. When one end of either heat pipe is subjected to heating, the fluid inside the heat pipe will be evaporated and transfers into vapour or gas. The evaporated gas or vapour further flow to the other end of the heat pipe and condense on the inside surface of the heat pipe 1 to dissipate heat carried from the evaporating end close to the heat source 6. The condensed liquid then flow back to the evaporated end (i.e. the end close to the heat source 6) through capillary effect. Hence, a cycle for heat transferring can be achieved inside the space or cavity of the heat pipe.
Please refer to FIG. 2. A cross-sectional view of a heat pipe is shown in FIG. 2. The cavity (or space) of the sealed container (i.e. heat pipe 1) is filled with a dissipation fluid 2 containing a solvent, a dispersant (not shown in FIG. 2) and multiple nanoparticles 3. In the present embodiment, the homogeneously distributed nanoparticles 3 can flow with the dissipation fluid 2 in the cavity of the heat pipe 1. In the present embodiment, the solvent is water and the dispersant is tetraethamine. The dispersant here is used for preventing aggregation of the nanoparticles and can keep the nanoparticles flow fluently. The concentration of nanoparticles 3 of the present embodiment is 1%. The nanoparticles used in the present embodiment are gold nanoparticles and the average diameter of the nanoparticles of the present embodiment is less than 17 nm. However, the diameter of the nanoparticles suitable for the apparatus of the present invention is not limited to 17 nm. Preferably, the adequate diameter of the nanoparticles of the present invention ranges from 1 nm to 500 nm. The solvent of the dissipation fluid of the present invention is not limited to be water. Other liquid for dissipating heat can be used for the solvent of the present invention. The nanoparticles of the present invention can be any conventional thermal conductive nanoparticles. Preferably, the nanoparticles of the present invention are metal nanoparticles or metal oxide nanoparticles. Most preferably, the nanoparticles of the present invention are made of gold, silver, copper, platinum, aluminum, titanium oxide, iron oxide, or fullerenes.
On the other hand, when bubbles are induced in the inside surface of the heat pipe by heat, the nanoparticles 3 can flow around the border of the bubbles or flow through the interspace between the bubbles. Hence, the bubbles won't block the flow of the nanoparticles. The nanoparticles can even burst part of the induced bubbles as the disturbance flow rate of the nanoparticles increased to a threshold rate and therefore increase the efficiency of heat transfer of heat pipes. Moreover, the surface of the nanoparticles will generate additional bubbles to increase the disturbance flow rate, and, of course, increase the efficiency of heat transfer again. Furthermore, the nanoparticles in the heat pipes also increase the capillary effect of heat pipe. This also helps the improvement of the efficiency of heat transfer.
Please refer to FIG. 3 and FIG. 4. FIG. 3 shows a mounting-base 4 (for laser diodes) for dissipating heat generated by laser diodes 41. The laser diode 41 is mounted on the top of the mounting-base 4. Combining a bottom-plate and a top-cover together through sealing makes the mounting-base. The inside structure of the bottom-plate 5 can be seen in FIG. 4. According to FIG. 4, several linear grooves 52 and semi-circle cavities 53 are formed in side the surface of a circular space 52 of the bottom-plate 5. The linear grooves 51 and the semi-circle cavities 51 are arranged radically in the circular space 52. The semi-circle cavities 53 are arranged on both ends of the linear grooves 51. The circular space 52, the semi-circle cavities 53 and the linear grooves 51 will form a closed cavity and function as heat pipes to confine the flow of the dissipation solvent and the nanoparticles when the bottom-plate 5 and the top-cover is combined and sealed. The assembled mounting-base can function as an effective heat-dissipation apparatus for carrying heat away from the laser diode and achieve the various functions illustrated above. The form of the sealed container is not limited. Preferably, the form of the container of the present invention is in a pipe shape. The sealed container of the present invention can be any conventional container but not limited to a heat pipe. Moreover, the position for subjecting heat source on the container of the present invention is not limited. The position is preferred to be the position on any end of the container or on the center part of the container. Of course, the portion for dissipating heat or transferring heat out of the container of the present invention is not limited. The portion for dissipating heat or carrying out heat on the container of the present invention is preferred to be on one end of the container or on the center part of the container.
Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.

Claims

1. An apparatus for heat dissipation, comprising:

a sealed container having a closed cavity; and

a dissipation fluid comprising plural nanoparticles and a solvent;

wherein said dissipation fluid is located in and is able to flow through said sealed closed cavity of said container.

2. The apparatus as claimed in claim 1, wherein said dissipation fluid further comprises at least a dispersant for preventing aggregation of said nanoparticles.

3. The apparatus as claimed in claim 2, wherein said dispersant is tetraethylamine or salts thereof.

4. The apparatus as claimed in claim 1, wherein the concentration of said nanoparticles ranges between 0.001% to 10%.

5. The apparatus as claimed in claim 1, wherein the diameter of said naoparticle ranges between 1 nm to 500 nm.

6. The apparatus as claimed in claim 1, wherein said solvent is water.

7. The apparatus as claimed in claim 1, wherein said nanoparticles are metallic nanoparticles.

8. The apparatus as claimed in claim 7, wherein said metallic nanoparticles are gold nanoparticles.

9. The apparatus as claimed in claim 1, wherein said sealed container is a micro-heat pipe.

10. A dissipation fluid for dissipating heat in a container having a closed cavity, comprising:

a solvent; and

plural nanoparticles dispersed in said solvent;

11. The dissipation fluid as claimed in claim 10, further comprising at least a dispersant for preventing aggregation of said nanoparticles.

12. The dissipation fluid as claimed in claim 11, wherein said dispersant is tetraethylamine or salts thereof.

13. The dissipation fluid as claimed in claim 10, wherein the concentration of said nanoparticle ranges between 0.001% to 10%.

14. The dissipation fluid as claimed in claim 10, wherein the diameter of said naoparticle ranges between 1 nm to 500 nm.

15. The dissipation fluid as claimed in claim 10, wherein said solvent is water.

16. The dissipation fluid as claimed in claim 10, wherein said nanoparticles are metallic nanoparticles.

17. The dissipation fluid as claimed in claim 16, wherein said metallic nanoparticles are gold nanoparticles.

18. The dissipation fluid as claimed in claim 10, wherein said sealed container is a micro-heat pipe.