U.S. patent application number 11/292258 was filed with the patent office on 2006-07-20 for heat pipe.
This patent application is currently assigned to Foxconn Technology CO., LTD.. Invention is credited to Ching-Tai Cheng, Chu-Wan Hong, Chang-Ting Lo, Jung-Yuan Wu.
Application Number | 20060157229 11/292258 |
Document ID | / |
Family ID | 36682683 |
Filed Date | 2006-07-20 |
United States Patent
Application |
20060157229 |
Kind Code |
A1 |
Hong; Chu-Wan ; et
al. |
July 20, 2006 |
Heat pipe
Abstract
A heat pipe (10) includes a pipe body (30) filled with working
fluid, a screen mesh (50) located in the pipe body, a porous
support member (70) supporting the screen mesh to contact with an
inner wall (32) of the pipe body.
Inventors: |
Hong; Chu-Wan; (Tu-Cheng,
TW) ; Cheng; Ching-Tai; (Tu-Cheng, TW) ; Lo;
Chang-Ting; (Tu-Cheng, TW) ; Wu; Jung-Yuan;
(Tu-Cheng, TW) |
Correspondence
Address: |
MORRIS MANNING & MARTIN LLP
1600 ATLANTA FINANCIAL CENTER
3343 PEACHTREE ROAD, NE
ATLANTA
GA
30326-1044
US
|
Assignee: |
Foxconn Technology CO.,
LTD.
Tu-Cheng City
TW
|
Family ID: |
36682683 |
Appl. No.: |
11/292258 |
Filed: |
December 1, 2005 |
Current U.S.
Class: |
165/104.26 |
Current CPC
Class: |
F28D 15/046
20130101 |
Class at
Publication: |
165/104.26 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 14, 2005 |
TW |
94101106 |
Claims
1. A heat pipe comprising: a hollow pipe body having an inner wall;
a mesh structure located in the pipe body, and a porous support
member supporting the mesh structure to contact with the inner wall
of the pipe body.
2. The cooling device as claimed in claim 1, wherein the support
member is disposed in a central portion of the pipe body, the mesh
structure is sandwiched between the pipe body and the support
member.
3. The cooling device as claimed in claim 1, wherein the support
member is column shaped and extends along an axial direction of the
pipe body.
4. The cooling device as claimed in claim 3, wherein support member
extends continuously along the axial direction of the pipe
body.
5. The cooling device as claimed in claim 4, wherein support member
extends discretely along the axial direction of the pipe body, and
comprises several sections and a space is defined between two
neighboring sections.
6. The cooling device as claimed in claim 1, wherein the support
member is hollow and defined a through hole in a central portion
thereof.
7. The cooling device as claimed in claim 1, wherein the support
member is solid.
8. The cooling device as claimed in claim 1, wherein the support
member is made of one of metal foam and porous polymer
material.
9. The cooling device as claimed in claim 8, wherein the metal foam
is selected from following material: copper, aluminum, magnesium,
nickel.
10. The cooling device as claimed in claim 8, wherein the porous
polymer material is polyethylene.
11. The cooling device as claimed in claim 1, wherein a volume
ratio of pores of the support member is larger than 50%.
12. A heat pipe comprising: a hollow pipe body having an inner
wall; a mesh structure disposed on the inner wall of the pipe body,
and a column shaped support member disposed in a central portion of
the pipe body to support the mesh structure to contact with the
inner wall of the pipe body, the support member having pores
therein for passage of vapor.
13. The cooling device as claimed in claim 12, wherein support
member is made of one of metal foam and porous polymer
material.
14. The cooling device as claimed in claim 13, wherein a volume
ratio of pores of the support member is larger than 50%.
15. The cooling device as claimed in claim 14, wherein the support
member is hollow and defined a through hole therein.
16. The cooling device as claimed in claim 14, wherein the support
member extends discretely along an axial direction of the pipe
body, and comprises several sections and a space is defined between
two neighboring sections.
17. A heat pipe comprising: a hollow pipe body having an inner
wall; a mesh structure received in the hollow pipe body; and a
support member made of metal foam received in the hollow pipe body
and pressing the mesh structure against the inner wall of the pipe
body.
18. The heat pipe of claim 17, wherein the support member is
continuously extended in the pipe body.
19. The heat pipe of claim 17, wherein the support member is
discrete in the pipe body.
20. The heat pipe of claim 17, wherein the support member is
hollow.
Description
TECHNICAL FIELD
[0001] The present invention relates to a heat pipe, and especially
to a support member for providing a support force to press the mesh
structure tightly against an inner wall of a pipe body of the heat
pipe.
BACKGROUND
[0002] As electronic industry continues to advance, electronic
components such as central processing units (CPUs), are made to
provide faster operational speeds and greater functional
capabilities. When a CPU operates at a high speed, its temperature
frequently increases greatly. It is desirable to dissipate the heat
generated by the CPU quickly.
[0003] To solve this problem of heat generated by the CPU, a
cooling device is often used to be mounted on top of the CPU to
dissipate heat generated thereby. It is well known that heat
absorbed by fluid having a phase change is ten times more than that
the fluid does not have a phase change; thus, the heat transfer
efficiency by phase change of fluid is better than other
mechanisms, such as heat conduction or heat convection. Thus, a
heat pipe has been developed.
[0004] The heat pipe has a hollow pipe body receiving working fluid
therein and a wick structure disposed on an inner wall of the pipe
body. During operation of the heat pipe, the working fluid absorbs
the heat generated by the CPU or other electronic device and
evaporates. Then the vapor moves to a condensing section of the
heat pipe to dissipate the heat thereof, whereby the vapor is
cooled and condensed at the condensing section. The condensed
working fluid returns to the evaporating section. The above process
is repeated and heat is continuously transferred from the
evaporating section into the condensing section.
[0005] In general, movement of the working fluid from the
condensing section to the evaporating section depends on capillary
action of the wick structure. Usually the wick structure has the
following four configurations: sintered powder, grooved, fiber and
screen mesh. For the thickness and porous size of the screen mesh
can be easily changed, the screen mesh is widely used in the heat
pipe.
[0006] Conventionally, the wick structure of screen mesh of the
heat pipe is tightly stuck to the inner wall of the pipe body by a
sintering process. The sintering process will soften the screen
mesh; thus, the screen mesh consequently cannot provide sufficient
support to allow the wick structure of screen mesh to adhere
tightly to the inner wall of the pipe body. This in turn adversely
affects the capillary action of the heat pipe as well as the
function thereof.
[0007] For the foregoing reasons, therefore, there is a need in the
art for a heat pipe which overcomes the above-mentioned
problems.
SUMMARY
[0008] According to a preferred embodiment of the present
invention, a heat pipe comprises a hollow pipe body for retaining a
working fluid therein, a mesh structure located in the pipe body,
and a porous support member received in the pipe body and
supporting the mesh structure to contact with an inner wall of the
pipe body. The porous support member is made of metal foam and
continuously extends in the pipe body.
[0009] Other objects, advantages and novel features of the present
invention will be drawn from the following detailed description of
a preferred embodiment of the present invention with attached
drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a longitudinally cross-sectional view of a heat
pipe in accordance with a preferred embodiment of the present
invention;
[0011] FIG. 2 is a transversely cross-sectional view of the heat
pipe of FIG. 1;
[0012] FIG. 3 is longitudinally cross-sectional view of a heat pipe
in accordance with a second embodiment of the present
invention;
[0013] FIG. 4 is a longitudinally cross-sectional view of a heat
pipe in accordance with a third embodiment of the present
invention; and
[0014] FIG. 5 is a transversely cross-sectional view of the heat
pipe of FIG. 4.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] Referring to FIGS. 1-2, a heat pipe 10 according to a
preferred embodiment of the present invention comprises a hollow
pipe body 30, a screen mesh 50 and a support member 70 for
supporting the screen mesh 50 received in the pipe body 30. The
heat pipe 10 is divided into an evaporating section, an adiabatic
section and a condensing section along an axial direction of the
heat pipe 10. The adiabatic section is located between the
evaporating and condensing sections.
[0016] The pipe body 30 is made of high heat conductivity material
such as copper or aluminum. A working fluid (not shown) is filled
in the hollow pipe body 30. The working fluid is water, alcohol or
other material having a low boiling point. Thus, the working fluid
can easily evaporate to vapor when it receives heat at the
evaporating section of the heat pipe 10. The heat pipe 10 is
vacuumed, and two ends thereof are sealed.
[0017] The screen mesh 50 is disposed on an inner wall 32 of the
pipe body 30. An outer diameter of the screen mesh 50 is
approximately the same as an inner diameter of the pipe body 30.
The screen mesh 50 is made of stainless steel, copper etc., which
can coexist with the working fluid. A plurality of pores is defined
in the screen mesh 50 for providing a capillary action to the
working fluid.
[0018] The support member 70 is received in a central portion of
the pipe body 30. Thus the screen mesh 50 is sandwiched between the
inner wall 32 of the pipe body 30 and the support member 70. The
support member 70 has a column shape. The support member 70 extends
continuously along an axial direction of the pipe body 30, and has
approximately the same length as the screen mesh 50. The support
member 70 is solid. The support member 70 has an outer diameter
substantially the same as an inner diameter of the screen mesh 50.
The support member 70 provides sufficient support to press the
screen mesh 50 tightly against the inner wall 32 of the pipe body
30 so that the screen mesh 50 can have an intimate contact with the
inner wall 32 of the pipe body 30.
[0019] The support member 70 is made of metal foam wherein the
metal can be copper, aluminum, magnesium, nickel etc.. A plurality
of pores is defined in the support member 70 for reducing the
resistance regarding the flowing of the vapor from the evaporating
section to the condensing section of the heat pipe 10. Also the
support member 70 can be made of other material having pores, for
example polyethylene or other porous polymer material. For reducing
the resistance of the flowing of the vapor, the volume ratio of the
pores of the support member 70 should be more than 50%.
[0020] During operation of the heat pipe 10, when the working fluid
saturated in the screen mesh 50 in the evaporating section of the
heat pipe 10 evaporates to vapor due to heat absorbed from a heat
source such as a CPU, vapor moves toward the condensing section of
the heat pipe 10 due to the difference of vapor pressure to perform
heat transport, and then cools and condenses in the condensing
section to perform heat dissipation. In this case, the condensed
working fluid enters the screen mesh 50 in the condensing section
and then returns to the evaporating section due to the difference
of capillary pressure between the condensing and evaporating
sections. Such a process is repeated so that heat is continuously
transferred from the evaporating section into the condensing
section.
[0021] Since the screen mesh 50 is tightly attached to the inner
wall 32 of the pipe body 30 by the support member 70, the capillary
action of the screen mesh 50 is improved, which in turn improves
the efficiency of the heat pipe 10.
[0022] Referring to FIG. 3, it illustrates an alternative
embodiment of the present invention. Except for the support member
72, other parts of the heat pipe 10 in accordance with this second
embodiment have substantially the same configuration with the heat
pipe 10 of the previous first preferred embodiment. According to
this second embodiment, along the axial direction of the heat pipe
10, the support member 72 is discrete. The support member 72
comprises several sections. A space 90 is defined between two
neighboring sections. The heat pipe 10 according to this embodiment
can be more easily bent to have a complicated shape, such as a
U-like shape or an S-like shape. The support member 72 with a
discrete configuration can reduce the resistance for the flowing of
the vapor from the evaporating section to the condensing section of
the heat pipe 10.
[0023] FIGS. 4-5 show a third embodiment of the present invention,
the difference between the third embodiment and the previous two
embodiments is that the support member 74 of this third embodiment
is hollow. A through hole 80 is defined in a central portion of the
support member 74. Thus, the third embodiment can further reduce
the flowing resistance of the vapor. Then the vapor can easily move
from the evaporating section toward the condensing section.
[0024] It is understood that the invention may be embodied in other
forms without departing from the spirit thereof. Thus, the present
example and embodiment is to be considered in all respects as
illustrative and not restrictive, and the invention is not to be
limited to the details given herein.
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