U.S. patent application number 13/045676 was filed with the patent office on 2012-09-13 for heat pipe having a composite wick structure and method for making the same.
This patent application is currently assigned to Kunshan Jue-Chung Electronics Co.. Invention is credited to Yu-Po HUANG.
Application Number | 20120227934 13/045676 |
Document ID | / |
Family ID | 46794456 |
Filed Date | 2012-09-13 |
United States Patent
Application |
20120227934 |
Kind Code |
A1 |
HUANG; Yu-Po |
September 13, 2012 |
HEAT PIPE HAVING A COMPOSITE WICK STRUCTURE AND METHOD FOR MAKING
THE SAME
Abstract
A heat pipe having a composite wick structure includes a first
pipe, a second pipe, a third wick structure, a working fluid, an
evaporating section, a condensing section and a transferring
section. The inner wall of the first pipe is provided with a first
wick structure. The evaporating section is formed on one side of
the first pipe. The condensing section is formed on the other side
of the first pipe. The transferring section is formed in the first
pipe between the evaporating section and the condensing section.
The second pipe is received in the first pipe and located in the
transferring section. The outer wall of the second pipe is provided
with a second wick structure. The third wick structure is provided
between the first wick structure and the second wick structure. The
working fluid is filled in the first pipe. By this structure, the
condensed working fluid in the first pipe can quickly flow from the
condensing section through the transferring section back to the
evaporating section. The present invention also provides a method
for making such a heat pipe.
Inventors: |
HUANG; Yu-Po; (Kunshan City,
CN) |
Assignee: |
Kunshan Jue-Chung Electronics
Co.
|
Family ID: |
46794456 |
Appl. No.: |
13/045676 |
Filed: |
March 11, 2011 |
Current U.S.
Class: |
165/104.26 ;
29/890.032 |
Current CPC
Class: |
F28D 15/0275 20130101;
Y10T 29/49353 20150115; B21D 41/045 20130101; B21D 53/06 20130101;
F28D 15/046 20130101 |
Class at
Publication: |
165/104.26 ;
29/890.032 |
International
Class: |
F28D 15/04 20060101
F28D015/04; B21D 53/02 20060101 B21D053/02 |
Claims
1. A heat pipe having a composite wick structure, including: a
first pipe provided with a first wick structure on its inner wall;
an evaporating section formed on one side of the first pipe; a
condensing section formed on the other side of the first pipe away
from the evaporating section; a transferring section formed in the
first pipe between the evaporating section and the condensing
section; a second pipe received in the first pipe and located in
the transferring section, an outer wall of the second pipe being
provided with a second wick structure; a third wick structure
provided between the first wick structure and the second wick
structure; and a working fluid filled in the first pipe.
2. The heat pipe having a composite wick structure according to
claim 1, wherein the first wick structure is constituted of a
plurality of grooves formed on the inner wall of the first
pipe.
3. The heat pipe having a composite wick structure according to
claim 2, wherein the second wick structure is constituted of a
plurality of grooves formed on the outer wall of the second
pipe.
4. The heat pipe having a composite wick structure according to
claim 3, wherein the grooves of the first pipe are aligned with the
grooves of the second pipe respectively.
5. The heat pipe having a composite wick structure according to
claim 3, wherein the grooves of the first pipe are staggered with
respect to the grooves of the second pipe respectively.
6. The heat pipe having a composite wick structure according to
claim 1, wherein the second wick structure is made of sintered
metal powder.
7. The heat pipe having a composite wick structure according to
claim 1, wherein the second wick structure is made of metallic
woven meshes.
8. The heat pipe having a composite wick structure according to
claim 1, wherein the third wick structure is made of sintered metal
powder.
9. The heat pipe having a composite wick structure according to
claim 1, wherein the third wick structure is made of metallic woven
meshes.
10. The heat pipe having a composite wick structure according to
claim 1, wherein the third wick structure is made of a bundle of
fibers.
11. The heat pipe having a composite wick structure according to
claim 1, wherein an inner wall surface of the second pipe is a
smooth surface.
12. The heat pipe having a composite wick structure according to
claim 1, wherein a solid body is formed in the evaporating section,
the solid body is constituted of the first wick structure and the
third wick structure.
13. The heat pipe having a composite wick structure according to
claim 1, wherein a hollow body is formed in the condensing section,
the hollow body is constituted of the first wick structure and the
third wick structure.
14. The heat pipe having a composite wick structure according to
claim 1, wherein the interior of the condensing section has the
first wick structure.
15. A method for making a heat pipe having a composite wick
structure, including steps of: a) providing a first pipe having a
first wick structure, narrowing and sealing one end of the first
pipe; b) providing a second pipe having a second wick structure,
inserting the second pipe into the first pipe to form a filling
space between the first wick structure and the second wick
structure; c) providing a third wick structure, filling the third
wick structure into the filling space; d) providing a heating
apparatus for heating the first wick structure, the second wick
structure and the third wick structure to form a composite wick
structure; e) providing a working fluid, filling the working fluid
into the first pipe; and f) providing a degassing and soldering
apparatus for degassing and sealing the first pipe.
16. The method according to claim 15, wherein the first wick
structure is formed of a plurality of grooves on an inner wall of
the first pipe.
17. The method according to claim 16, wherein the second wick
structure is constituted of a plurality of grooves on an outer wall
of the second pipe.
18. The method according to claim 17, wherein the grooves of the
first pipe are aligned with the grooves of the second pipe
respectively.
19. The method according to claim 17, wherein the grooves of the
first pipe are staggered with respect to the grooves of the second
pipe respectively.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a heat pipe, in particular
to a heat pipe having a composite wick structure and a method for
making the same.
[0003] 2. Description of Prior Art
[0004] A heat-pipe type heat sink constituted of heat pipes and a
heat-dissipating fin set can solve the problem relating to heat
dissipation of a processor which generates more and more amount of
heat recently. Thus, such a heat-pipe type heat sink has already
replaced a conventional heat sink constituted of heat-dissipating
fins and a fan. However, the existing heat pipes still have
problems with regard to its heat-conducting rate and the slow
reflow of an internal working fluid. Therefore, it is an important
issue for the present Inventor to solve the above-mentioned
problems.
[0005] The conventional heat pipe includes a metallic pipe, a wick
structure and a working fluid.
[0006] The metallic pipe has a sealed chamber. The wick structure
is provided on inner walls of the metallic pipe. The working fluid
is filled in the sealed chamber of the metallic pipe. An air
channel is formed inside the wick structure. The wick structure
serves as a liquid reflow channel. By this arrangement, the
conventional heat pipe is obtained.
[0007] The conventional heat pipe transfers the heat by means of
the liquid-vapor phase transition of the working fluid, however,
the wick structure in the conventional heat pipe is formed as only
one layer. Thus, the reflow rate of the working fluid is restricted
by the one-layer wick structure. Further, since the vapor-flowing
direction is opposite to the liquid-reflowing direction, and the
air channel is arranged adjacent to the liquid channel, the
vapor-flowing rate and the liquid-reflowing rate may be negatively
affected due to the interference occurred in an adjoining area
between the air channel and the liquid channel. As a result, the
heat-conducting performance of the conventional heat pipe cannot be
enhanced further.
SUMMARY OF THE INVENTION
[0008] The present invention is to provide a heat pipe having a
composite wick structure and a method for making the same. With a
multi-layer composite wick structure in a transferring section of
the heat pipe, the working fluid condensed in the condensing
section of the heat pipe can quickly flow through the transferring
section back to the evaporating section.
[0009] The present invention provides a heat pipe having a
composite wick structure, including a first pipe, a second pipe, a
third wick structure, a working fluid, an evaporating section, a
condensing section and a transferring section. A first wick
structure is provided on inner walls of the first pipe. The
evaporating section is formed on one side of the first pipe. The
condensing section is formed on the other side of the first pipe
away from the evaporating section. The transferring section is
provided in the first pipe between the evaporating section and the
condensing section. The second pipe is received in the first pipe
and located in the transferring section. A second wick structure is
formed on outer walls of the second pipe. The third wick structure
is provided between the first wick structure and the second wick
structure. The working fluid is filled in the first pipe.
[0010] The present invention provides a method for making a heat
pipe having a composite wick structure, including steps of:
[0011] a) providing a first pipe having a first wick structure,
narrowing and sealing one end of the first pipe;
[0012] b) providing a second pipe having a second wick structure,
inserting the second pipe into the first pipe to form a filling
space between the first wick structure and the second wick
structure;
[0013] c) providing a third wick structure, filling the third wick
structure into the filling space;
[0014] d) providing a heating apparatus for heating the first wick
structure, the second wick structure and the third wick structure
to form a composite wick structure;
[0015] e) providing a working fluid, filling the working fluid into
the first pipe; and
[0016] f) providing a degassing and soldering apparatus for
degassing and sealing the first pipe.
[0017] The present invention has the following advantageous
effects. The first pipe and the second pipe are arranged to
separate an air channel from a liquid channel in the transferring
section. The liquid-phase working fluid and the vapor-phase working
fluid can be transferred quickly without any interference, thereby
increasing the heat-conducting performance of the heat pipe.
BRIEF DESCRIPTION OF DRAWING
[0018] FIG. 1 is an assembled cross-sectional view of a heat pipe
of the present invention;
[0019] FIG. 2 is an assembled view showing that a second pipe is
inserted into a first pipe according to the present invention;
[0020] FIG. 3 is a cross-sectional view of a condensing section
taken along the line 3-3 in FIG. 1;
[0021] FIG. 4 is a cross-sectional view of a transferring section
taken along the line 4-4 in FIG. 1;
[0022] FIG. 5 is a cross-sectional view of an evaporating section
taken along the line 5-5 in FIG. 1;
[0023] FIG. 6 is an assembled view showing that the heat pipe of
the present invention is applied to an electronic heat-generating
element;
[0024] FIG. 7 is an assembled cross-sectional view showing the heat
pipe of another embodiment of the present invention;
[0025] FIG. 8 is a flow chart showing the method for making the
heat pipe of the present invention;
[0026] FIG. 9 is an assembled cross-sectional view showing the heat
pipe of a further embodiment of the present invention; and
[0027] FIG. 10 is an assembled cross-sectional view showing the
heat pipe of a still further embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The detailed description and technical contents of the
present invention will become apparent with the following detailed
description accompanied with related drawings. It is noteworthy to
point out that the drawings is provided for the illustration
purpose only, but not intended for limiting the scope of the
present invention.
[0029] Please refer to FIGS. 1 to 5. The present invention provides
a heat pipe having a composite wick structure. The heat pipe 1
includes a first pipe 10, a second pipe 20, a third wick structure
30 and a working fluid 40.
[0030] Please refer to FIG. 2 first. The first pipe 10 is made of
metal having good thermal conductivity, such as copper. The inner
walls of the first pipe 10 are provided with a plurality of grooves
11 arranged at intervals in parallel to an axial line of the first
pipe 10. Each of the grooves 11 is configured to extend through the
front and rear ends of the first pipe 10. These grooves 11 form the
first wick structure 12 of the present embodiment, but it is not
limited thereto.
[0031] The second pipe 20 is also made of metal having good thermal
conductivity, such as copper. Outer walls of the second pipe 20 are
provided with a plurality of grooves 21 arranged at intervals in
parallel to an axial line of the second pipe 20. Each of the
grooves 21 is configured to extend through the front and rear ends
of the second pipe 20. These grooves 21 form the second wick
structure 22 of the present embodiment, but it is not limited
thereto. On the other hand, the inner wall surface of the second
pipe is a smooth surface 23. The length and diameter of the second
pipe 20 are both smaller than those of the first pipe 10, so that
the second pipe 20 can be received in a middle portion of the first
pipe 10. The grooves 21 of the second pipe 20 may be aligned with
the grooves 11 of the first pipe 10 respectively as shown in FIG.
4. Alternatively, the grooves 21 of the second pipe 20 may be
staggered with respect to the grooves 11 of the first pipe 10
respectively as shown in FIG. 10. The second wick structure 22 may
be made of sintered metal powder or metallic woven meshes (not
shown).
[0032] The third wick structure 30 of the present embodiment is
made of sintered metal powder, but it is not limited thereto. The
third wick structure 30 is filled in the first pipe 10, and a
portion of the third wick structure 30 is located between the first
wick structure 12 and the second wick structure 22. By this
arrangement, the second pipe 20 can be firmly supported and
position in the first pipe 10.
[0033] The working fluid 40 may be pure water, which is filled in
the first pipe 10. After the interior of the first pipe 10 is
degassed to become vacuum, the first pipe 10 is sealed to obtain a
desired heat pipe 1.
[0034] According to the thermal contact location in practice use,
the heat pipe 1 can be divided into an evaporating section 100, a
condensing section 101 and a transferring section 102 as shown in
FIG. 1. The evaporating section 100 is brought into thermal contact
with a heat source 6 as shown in FIG. 6. The condensing section 101
is brought into thermal contact with a heat-dissipating fin set 7
as shown in FIG. 6 and is located away from the evaporating section
100. The transferring section 102 is located between the
evaporating section 100 and the condensing section 101. In the
present embodiment, the second pipe 20 is located in the
transferring section 102 of the heat pipe 1. In the transferring
section 102, the first wick structure 12, the second wick structure
22 and the third wick structure 30 constitute a three-layer
composite wick structure.
[0035] Please refer to FIG. 6. The heat pipe 1 of the present
invention can be combined with the heat-dissipating fin set 7 for
dissipating the heat generated by an electronic heat-generating
source 6 (such as a processing chip) on a mother board. The
evaporating section 100 of the heat pipe 1 is adhered to a
heat-generating surface of the electronic heat-generating source 6,
so that the heat generated by the electronic heat-generating source
6 can be absorbed by the evaporating section 100. As a result, the
liquid-phase working fluid 40 in the evaporating section 100 is
heated to become a vapor-phase working fluid 40. The vapor-phase
working fluid 40 flows through the second pipe 20 in the
transferring section 102. The smooth surface 23 inside the second
pipe 20 has a smaller flow resistance, so that the vapor-phase
working liquid 40 can pass through the second pipe 20 quickly and
then arrive the condensing section 101 in the first pipe 10. With
the heat-dissipating fin set 7 connected to the condensing section
101, the latent heat of the vapor-phase working fluid 40 can be
released and dissipated to the outside, whereby the vapor-phase
working fluid 40 is condensed into a liquid-phase working fluid 40.
The working fluid 40 condensed in the condensing section 101 flows
back to the transferring section 102 by means of a capillary force
generated by the first wick structure 12 and the third wick
structure 30. Then, the condensed working fluid 40 flows from the
transferring section 102 back to the evaporating section 100 by
means of a larger capillary force generated by the composite wick
structure constituted of the first wick structure 12, the second
wick structure 22 and the third wick structure 30. In this way, the
working fluid 40 can be continuously circulated in the heat pipe
1.
[0036] Please refer to FIG. 7. In addition to the above embodiment,
the present invention can be carried out in another aspect, in
which only the first wick structure 12 is formed in the condensing
section 101 of the heat pipe V. Due to its small thermal
resistance, the first wick structure 12 can accelerate the flowing
rate of the working fluid 40 in the heat pipe V.
[0037] Please refer to FIGS. 1 and 8. The present invention
provides a method for making a heat pipe having a composite wick
structure, which includes steps of:
[0038] a) providing a first pipe 10 having a first wick structure
12, narrowing and sealing one end of the first pipe 10;
[0039] b) providing a second pipe 20 having a second wick structure
22, inserting the second pipe 20 into the first pipe 10 to form a
filling space between the first wick structure 12 and the second
wick structure 22;
[0040] c) providing a third wick structure 30, filling the third
wick structure 30 into the filling space;
[0041] d) providing a heating apparatus for heating the first wick
structure 12, the second wick structure 22 and the third wick
structure 30 to form a composite wick structure;
[0042] e) providing a working fluid 40, filling the working fluid
40 into the first pipe 10; and
[0043] f) providing a degassing and soldering apparatus for
degassing and sealing the first pipe 10.
[0044] More specifically, in the present embodiment, if the third
wick structure 30 is made of sintered metal powder, a core rod (not
shown) has to be inserted into the second pipe 20 first. Then, as
shown in FIG. 2, the second pipe 20 together with the core rod are
inserted into the first pipe 10, thereby forming a filling space
between the first wick structure 12 and the second wick structure
22. Thereafter, metal powder is filled in the filling space. Then,
a heating apparatus (not shown) is used to sinter the metal powder
to form a composite wick structure constituted of the first wick
structure 12, the second wick structure 22 and the third wick
structure 30 made of sintered metal powder.
[0045] As shown in FIG. 5, in the evaporating section 100, a solid
body is formed by the first wick structure 12 constituted of the
grooves 11 and the third wick structure 30 made by sintered metal
powder. As shown in FIG. 3, in the condensing section 101, a hollow
body is formed by the first wick structure 12 constituted of the
grooves 11 and the third wick structure 30 made of sintered metal
powder.
[0046] Please refer to FIGS. 9 and 10. In addition to the above
embodiment, the third wick structure 30 of the present invention
may be made by metallic woven meshes shown in FIG. 9 or a bundle of
fibers shown in FIG. 10.
[0047] Although the present invention has been described with
reference to the foregoing preferred embodiments, it will be
understood that the invention is not limited to the details
thereof. Various equivalent variations and modifications can still
occur to those skilled in this art in view of the teachings of the
present invention. Thus, all such variations and equivalent
modifications are also embraced within the scope of the invention
as defined in the appended claims.
* * * * *