US20090139696A1

US20090139696A1 - Flat heat pipe with multi-passage sintered capillary structure

Info

Publication number: US20090139696A1
Application number: US11/949,684
Authority: US
Inventors: Ming-Cyuan Shih; Sin-Wei He
Original assignee: Forcecon Technology Co Ltd
Current assignee: Forcecon Technology Co Ltd
Priority date: 2007-12-03
Filing date: 2007-12-03
Publication date: 2009-06-04

Abstract

The flat heat pipe with multi-passage sintered capillary structure includes a flat pipe, which is a hollow pipe with a flat cross section and two sealed ends. Two flat surfaces and two lateral parts are defined. The flat pipe forms a heating section and a cooling section. A hollow chase is formed within the flat pipe. The sintered capillary structure is prefabricated into the hollow chase and is provided with at least two coupling sides for mating with two flat surfaces of the flat pipe. At least two flow passages are formed at intervals onto a preset location of the sintered capillary structure and arranged along the extension direction of the flat pipe.

Description

CROSS-REFERENCE TO RELATED U.S. APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT

Not applicable.

REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates generally to a heat pipe, and more particularly to an innovative heat pipe with a multi-passage sintered capillary structure.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
With continuous improvement in the performance of computers, heat-radiating components of higher performance are required. So, the development of the heat pipe in heat-radiating components is of paramount significance.
In a heat pipe structure, the working fluid is guided rapidly by capillary structure from the cooling end to the heating end. On the other hand, a hollow passage is used to quickly guide vaporized working fluid from the heating end to the cooling end. Thus, the key to this technology is the capillary structure and flow passage.
Currently, the capillary structure in a heat pipe is generally divided into a wire mesh, a powder sintered body and a groove. As for the wire mesh, the complicated manufacturing process requires processing the wire mesh into rolls and then plugging the wire mesh into the heat pipe, thus leading to higher manufacturing costs. Moreover, a gap exists between the wire mesh and heat pipe, so the heat flow in the passage may be blocked at the bending section, leading to degraded heat-insulating performance. The typical powder sintered body faces the same disadvantages as those for the aforementioned wire mesh. The powder sintered bodies are regularly distributed onto the inner wall of heat pipe to define a single passage. However, it is found that the single-passage space or capillary structure (powder sintered body) cannot help to improve the heat-radiating efficiency.
Thus, to overcome the aforementioned problems of the prior art, it would be an advancement in the art to provide an improved structure that can significantly improve efficacy.
Therefore, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products.

BRIEF SUMMARY OF THE INVENTION

The sintered capillary structure is prefabricated into a hollow chase of the flat pipe, so the objects to be sintered are placed into the flat pipe. Some core materials are combined to form a flat heat pipe with the multiple-passage sintered capillary structure, presenting simple manufacturing and cost-effectiveness.
Based on the structural feature that the sintered capillary structure is provided with at least two coupling sides for mating with two flat surfaces of the flat pipe, an excellent heat transfer effect could be achieved between the sintered capillary structure and flat pipe. The flat pipe could be supported more stably by the sintered capillary structure. Moreover, when the flat pipe is bent, the sintered capillary structure could bend accordingly to ensure smooth flow in the passage. Any flat surface of the flat pipe could contact the heat-radiating object for heat transfer, thus improving the flexibility of installation and preventing error of installation with improved applicability.
Based on the feature that the sintered capillary structure is provided at least with two flow passages, the vaporization space of the flow passage and guide area could be expanded to improve greatly the heat transfer and radiation effect of the flat heat pipe.
As a space is shaped between the sintered capillary structure and one end of the cooling section, the flow passage is provided with connecting space at the end. Thus, when the working fluid in flow passage is vaporized at different rates, the connecting space W2 could assist in achieving uniform temperature and improving the heat-radiation efficiency.
Although the 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.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows a perspective view of the preferred embodiment of the present invention.

FIG. 2 shows a sectional view of the preferred embodiment of the present invention.

FIG. 3 shows a sectional view of a first application of the flow passage configuration of the present invention.

FIG. 4 shows a sectional view of a second application of the flow passage configuration of the present invention.

FIG. 5 shows a sectional view of the flow passage configuration of the present invention.

FIG. 6 shows a sectional view of the application of the flow passage configuration of the present invention.

FIG. 7 shows a sectional view of the application of the flow passage of the present invention.

FIG. 8 shows another sectional view of the application of the flow passage of the present invention which is provided with a mesh body.

FIG. 9 shows a sectional view of the application of the inner wall of the hollow chase of the present invention which is provided with a groove.

FIG. 10 shows a schematic view of another application of the sintered capillary structure of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of a preferred embodiment of the present invention with reference to the accompanying drawings.
FIGS. 1-2 depict preferred embodiments of a flat heat pipe with multi-passage sintered capillary structure. The embodiments are only provided for explanatory purposes with respect to the patent claims.
The flat heat pipe comprises a flat pipe 10, which is a hollow pipe with a flat cross section and two sealed ends, defining two flat surfaces 11 and two lateral parts 12. The flat pipe 10 comprises a heating section 13 and a cooling section 14. A hollow chase 15 is formed within the flat pipe. The heating section 13 can be located at the end or middle section of the flat pipe 10, and the cooling section 14 at one or two ends of the flat pipe 10.
A sintered capillary structure 20 is made of metal powder or grains. The sintered capillary structure 20 is prefabricated into a hollow chase 15 of the flat pipe 10 and is provided at least with two coupling sides 21 for mating with two flat surfaces 11 of the flat pipe 10.
At least two flow passages 30 are formed at intervals onto preset locations of the sintered capillary structure 20 and arranged along the extension direction of flat pipe 10.
Referring to FIG. 2, the circumference of sintered capillary structure 20 is filled into the inner wall of hollow chase 15 of the flat pipe 10.
FIG. 2 depicts a structural pattern with two flow passages 30, wherein the flow passages 30 are formed within the sintered capillary structure 20. FIG. 3 depicts the application view of a plurality of flow passage 30. In the preferred embodiment, the flat surface 11 of the flat pipe 10 is expanded so that the flat pipe 10 is used as a soaking plate for heat-radiation of LED lamps.
Said flow passage 30 is also formed between the sintered capillary structure 20 and lateral part 12 and/or flat surface 11 of the flat pipe 10. Referring to FIG. 4, the sintered capillary structure 20 only allows two coupling sides 21 to be fixed with two flat surfaces 11 of the flat pipe 10. No sintered capillary structure 20 is arranged onto the inner wall of two lateral parts 12 of the flat pipe 10. The flow passage 30 is also formed between two sides of the sintered capillary structure 20 and inner wall of two lateral parts 12 of the flat pipe 10. FIG. 5 depicts the change of structural pattern in FIG. 4, wherein the sintered capillary structure 20 is additionally provided with a flow passage 30.
Referring to FIG. 6, the flow passage 30 in the sintered capillary structure 20 is also offset at flat surface 11 of the flat pipe 10.
Referring to FIG. 7, the flow passage 30 is designed with other cross sections (e.g. diamond-shaped cross section).
Referring to FIG. 8, the flow passage 30 is provided with a mesh body 40 (e.g. metal mesh grid) or porous components.
Referring to FIG. 9, grooves 50 are formed on the inner wall of hollow chase 15 of the flat pipe 10, so that the coupling area of sintered capillary structure 20 and hollow chase 15 could be further expanded to provide a more stable state of sintered capillary structure 20, and also to improve the heat transfer efficiency between the flat pipe 10 and sintered capillary structure 20.
The flat heat pipe of the present invention is shown in FIGS. 1 and 2. As the flat pipe 10 is provided with two flat surfaces 11 and the sintered capillary structure 20 is provided with two coupling sides 21, any flat surface 11 of the flat pipe 10 contacts the heat-radiating object (e.g. CPU) for heat transfer, thus improving the flexibility of installation. When the flat surface 11 absorbs heat energy, the heat energy will be directly transferred to the sintered capillary structure 20 for vaporization of working fluid. Next, the heat energy is guided via flow passage 30 to the cooling section 14 of the flat pipe 10, then the cooled working fluid will be transferred back to the heating section 13 through the sintered capillary structure 20.
Referring to FIG. 10, the flat pipe 10 is in a semi-finished state, wherein one end of the heating section 13 is closed, and one end of the cooling section 14 is opened. The internal flow passage 30 permits forming of sintered capillary structure 20 through the core rods 60 arranged alternatively. A structural pattern with a spacing W is shaped between the sintered capillary structure 20 and one end of the cooling section 14, so that the flow passages 30 are provided with connecting space W2 at the end. Thus, when the working fluid in flow passages 30 is vaporized at different rates since various regions of the flat pipe 10 are heated to different extent, the connecting space W2 could assist in achieving uniform temperature and improving the heat-radiation efficiency.

Claims

1. A flat heat pipe with multi-passage sintered capillary structure, comprising:

a flat pipe, being hollow and having a flat cross section and two sealed ends, defining two flat surfaces and two lateral parts, said flat pipe having a heating section and a cooling section, and a hollow chase formed therein;

a sintered capillary structure, being prefabricated into a hollow chase of said flat pipe, said sintered capillary structure being provided with at least two coupling sides mated with said two flat surfaces of said flat pipe; and

at least two flow passages, formed at intervals onto a preset location of said sintered capillary structure and arranged along an extension direction of said flat pipe.

2. The flat heat pipe defined in claim 1, wherein the circumference of sintered capillary structure is filled into the inner wall of hollow chase of the flat pipe.

3. The flat heat pipe defined in claim 1, wherein said flow passages are formed within said sintered capillary structure.

4. The flat heat pipe defined in claim 1, wherein said flow passages are formed between said sintered capillary structure and a flat surface of said flat pipe.

5. The flat heat pipe defined in claim 1, wherein said flow passage is provided with a mesh body or porous components.

6. The flat heat pipe defined in claim 1, wherein said flat piper further comprises grooves formed on an inner wall of said hollow chase of said flat pipe.

7. The flat heat pipe defined in claim 1, further comprising:

a space shaped between said sintered capillary structure and one end of the cooling section, said flow passage being provided with a connecting space at an end thereof.