U.S. patent application number 11/292253 was filed with the patent office on 2006-09-21 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 | 20060207751 11/292253 |
Document ID | / |
Family ID | 37009097 |
Filed Date | 2006-09-21 |
United States Patent
Application |
20060207751 |
Kind Code |
A1 |
Hong; Chu-Wan ; et
al. |
September 21, 2006 |
Heat pipe
Abstract
A heat pipe includes a hollow tube, a working medium filled in
the tube, and a wick structure disposed in and contacting with the
tube. The wick structure is formed by weaving first wires and
second wires together. The second wires each have two opposite
major surfaces. A portion of one of the two major surfaces contacts
with an interior wall of the tube.
Inventors: |
Hong; Chu-Wan; (Tu-Cheng,
TW) ; Cheng; Ching-Tai; (Tu-Cheng, TW) ; Wu;
Jung-Yuan; (Tu-Cheng, TW) ; Lo; Chang-Ting;
(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: |
37009097 |
Appl. No.: |
11/292253 |
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 |
Mar 18, 2005 |
TW |
94108403 |
Claims
1. A heat pipe comprising: a hollow tube; a working medium filled
in the tube; and a wick structure disposed in and contacting with
the tube, the wick structure comprising a plurality of first and
second wires woven together, the wick structure contacting an
interior wall of the tube mainly by the second wires, and the first
wires and the second wires having different cross sections.
2. The heat pipe as described in claim 1, wherein the second wires
are more flexible than the first wires.
3. The heat pipe as described in claim 2, wherein each of the first
wires has a cross section which is one of round, square, and
I-shaped.
4. The heat pipe as described in claim 3, wherein each of the
second wires has a stripe-like configuration.
5. The heat pipe as described in claim 1, wherein the first wires
and second wires are made of different materials, respectively.
6. The heat pipe as described in claim 5, wherein the first wires
and second wires are made of different metals.
7. The heat pipe as described in claim 1, wherein the first wires
extend along an axial direction of the tube while the second wires
extend along a circumferential direction of the tube.
8. The heat pipe as described in claim 1, wherein the second wires
each have two opposite major surfaces, one of the two opposite
major surfaces contacting with the interior wall of the tube.
9. The heat pipe as described in claim 1, wherein the wires are
made of at least one of copper, aluminum, and stainless steel.
10. A heat pipe comprising: a tube; a wick structure rolled and
inserted into the tube, the wick structure having first wires and
second wires woven together, the first wires extending along an
axial direction of the tube while the second wires extending along
a circumferential direction of the tube, the second wires each
being made of a stripe having two major surfaces alternately
contacting the first wires, a portion of one of the two major
surfaces of the second wires contacting an interior wall of the
tube.
11. The heat pipe of claim 10, wherein the first wires each have a
round cross section.
12. The heat pipe of claim 10, wherein the first wires each have a
substantially square cross section.
13. The heat pipe of claim 10, wherein the first wires each have an
I-shaped cross section.
14. The heat pipe of claim 10, wherein the second wires are more
flexible than the first wire.
15. The heat pipe of claim 10, wherein the wires are made of
metal.
16. The heat pipe of claim 10, wherein the first and second wires
are made of different metals, respectively.
17. A heat pipe comprising: a tube made of metal; a wick structure
attached on an interior wall of the tube and having first metal
wires and second metal wires woven together, wherein the first
metal wires extend along an axial direction of the tube and the
second metal wires extend along a circumferential direction of the
tube, wherein the second metal wires are more flexible than the
first metal wires.
18. The heat pipe of claim 17, wherein the second metal wires each
have a rectangular cross section with two major surface, a portion
of one of the two major surface being in contact with the interior
wall of the heat pipe.
19. The heat pipe of claim 18, wherein the first metal wires each
have a round cross section.
20. The heat pipe of claim 18, wherein the first metal wires each
have an I-shaped cross section.
Description
TECHNICAL FIELD
[0001] The present invention relates to a heat pipe, and more
specifically to a heat pipe having a better heat exchange
capability by increasing contacting areas between a wick structure
and an interior wall of the heat pipe.
BACKGROUND
[0002] In nowadays, heat pipes are always used in a heat
dissipating apparatus for dissipating heat generated by high
frequency electronic components. Each of the heat pipes includes an
evaporator section adjacent to the electronic components and a
condenser section apart from the electronic components. In the heat
dissipating apparatus, the heat pipes are usually received in holes
disposed in a group of spaced cooling fins with the evaporator
sections and the condenser sections of the heat pipes separately
positioned at two ends of the group of the cooling fins, for
conducting heat from the electronic components to the fins apart
from the electronic components. A dissipating fan is mounted to the
cooling fins for generating airflows facing to spaces formed
between two adjacent cooling fins to take away the heat conducted
to the cooling fins from the electronic components.
[0003] In working procession of the heat dissipating apparatus, a
tube of each heat pipe absorbs heat generated by the electronic
components and conducts the heat to a wick structure contacted with
an inner surface of the tube. At the evaporator section of the heat
pipe, a working fluid filled in the heat pipe absorbs heat from the
wick structure and the tube for evaporating itself to a steam. This
increases a vapor pressure in a region of the evaporator section of
the heat pipe and causes the steam to flow through a vapor space of
the heat pipe toward the condenser section. Since the condenser
section of the heat pipe being cooled by the cooling fins located
thereat, the steam condenses in the condenser section by giving up
the heat absorbed by the working fluid at the evaporator section,
thereby changing the steam to a liquid. The liquid returns to the
evaporator section by capillary action of the wick structure. With
the heat generated by the electronic components being absorbed by
the working fluid at the evaporator section of the heat pipe, and
the heat being given away by the evaporated working fluid at the
condenser section of the heat pipe, a circulation of the working
fluid are formed in the heat pipe. The heat generated by the
electronic components is continuously taken away by the working
fluid of the heat pipe during the circulation.
[0004] In this heat dissipating procession, the heat of the wick
structure absorbed from the inner surface of the tube of the heat
pipe acts an important influence of the heat transferring between
the tube and the working fluid, and further influences the
evaporating velocity of the working fluid and the heat transfer
capability of the heat pipe. The additional mesh type wick
structure is woven by a plurality of wires, the cross sectional of
the wire is a circle. This makes a contacting area of the circular
wire and the inner surface of the heat pipe to be a line. The
linear contacting between the circular wire of the wick structure
and the inner surface of the tube reduces the heat conducting
capability of the heat pipe. So how to increase the contacting area
of the wick structure and the inner surface of the heat pipe is a
problem we want to solve.
SUMMARY OF THE INVENTION
[0005] According to a preferred embodiment of the present
invention, a heat pipe includes a hollow tube, a working medium
filled in the tube, and a wick structure disposed in and contacting
with the tube. The wick structure is formed by weaving a plurality
of first and second wires. The second wires each have two opposite
major surfaces. One of the two major surface contacts with an
interior wall of the tube, whereby the wick structure has a large
surface in contacting with the tube. Accordingly, heat transfer
capability of the heat pipe is improved.
[0006] Other advantages and novel features of the present invention
will become more apparent from the following detailed description
of preferred embodiment when taken in conjunction with the
accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of a heat pipe according to a
preferred embodiment of the present invention, wherein some
portions of the heat pipe are cut away to show an internal
structure thereof;
[0008] FIG. 2 is a perspective view of a wick structure of the heat
pipe of FIG. 1 in an unrolled condition;
[0009] FIG. 3 is an enlarged view of a circled portion of FIG. 2
indicated by III;
[0010] FIG. 4 is an enlarged perspective view of a portion of a
wick structure in an unrolled condition according to another
embodiment of the present invention; and
[0011] FIG. 5 is a view similar to FIG. 4, showing a wick structure
according to a third embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0012] Referring to FIG. 1, a heat pipe 10 according to a first
embodiment of the present invention includes a hollow tube 12, a
wick structure 14 disposed in and contacting with an interior wall
of the tube 12, and a working medium (not shown) filled in the tube
12.
[0013] The tube 12 is made of a material having a good heat
conductivity, so that the tube 12 can transfer a heat absorbed from
a heat generating component (not shown) to the wick structure 14
and the working medium filled in the tube 12 rapidly. In this
embodiment, the tube 12 is made of copper.
[0014] The working medium is made of a fluid having a lower boiling
point, such as water, alcohol, kerosene, and paraffin. The tube 12
is vacuumed. The working medium filled in the tube 12 of the heat
pipe 10 can easily become vapor after absorbing heat from the tube
12. The vapor is capable of moving from an evaporator portion
toward a condenser portion of the tube 12. The vapor condenses into
liquid at the condenser portion. The liquid is drawn back to the
evaporator portion by capillary force of the wick structure 14 of
the heat pipe 10.
[0015] Also referring to FIGS. 2 and 3, the wick structure 14 is
formed by weaving a plurality of first wires 141 and a plurality of
second wires 142 together. The first wires 141 each have a rod
configuration while the second wires 142 each has a stripe
configuration. The first wires 141 each have a round cross section
and the second wires 142 each have a rectangular-shaped cross
section. The second wires 142 are more flexible than the first
wires 141. After rolled and inserted into the tube 12, the first
wires 141 extend along an axial direction of the tube 12, while the
second wires 142 extend along a circumferential direction of the
tube 12. Each second wire 142 has two opposite major surfaces 143,
144 contacting with the first wires 141 in an alternated manner.
After rolled and inserted into the tube 12, the wick structure 14
has an outer surface 145 contacting with the interior wall of the
tube 12. The outer surface 145 is constituted by a portion of a
corresponding one of the opposite major surfaces 143, 144 of each
second wire 142 not engaging with the first wires 141. Since the
major surfaces 143, 144 of the second wires 142 are planar, the
outer surface 145 of the wick structure 14 can have a larger area
in contacting with the interior wall of the tube 12 in comparison
with the prior art. This increases the heat transfer between the
interior wall of the tube 12 and the wick structure 14 of the heat
pipe 10, thereby improving the heat transfer capability of the heat
pipe 10.
[0016] Moreover, in the present invention, since the area of the
contacting surface between the tube 12 and the wick structure 14 is
increased, the heat absorbed by the tube 12 from the heat
generating component can be quickly transferred to the wick
structure 14 and then to the working medium. Accordingly, the
evaporation speed of the working medium is increased, and the heat
transfer capability of the heat pipe 10 with this wick structure 14
is improved.
[0017] Referring to FIGS. 4 and 5, wick structures 14', 14'' in
accordance with the second and third embodiments of the present
invention are shown. Except the difference regarding the cross
section of the first wires, the second and third embodiments are
substantially the same as the first embodiment. In the second
embodiment, the cross section of each of the first wires 141' is
changed to be substantially square. In the third embodiment, the
cross section of the first wires 141'' is changed to be I-shaped.
Alternatively, the cross section of the second wires 142 may be in
square, or I-shaped. This makes the first and second wires 141, 142
constituting the wick structure 14 have the same or two different
shapes of cross sections. The first wires 141 may extend along a
direction defining a sharp angle with the axial direction of the
tube 12, while the second wires 142 may extend along a direction
defining a sharp angle with the circumferential direction of the
tube 12. The second wires 142 may have the same flexibility with
the first wires 141. Thus, the first wires 141 may be in
ripple-like style and intersect with the second wires 142.
[0018] In the present invention, the first wires 141, 141', 141''
and the second wires 142 are made of metallic materials such as
copper, aluminum, nickel, and stainless steel, which have good heat
conductivity and strength. The wick structure 14, 14', 14'' may be
woven by wires of one material or two different materials.
[0019] In the preferred embodiments of the present invention, the
wick structure 14, 14', 14'' can have a better contact with the
interior wall of the tube 12 by inserting a supporting member into
the tube 12. The wick structures 14, 14', 14'' and the support
member can be further sintered to integrally connect with each
other.
[0020] It is to be understood, however, that even though numerous
characteristics and advantages of the present invention have been
set forth in the foregoing description, together with details of
the structure and function of the invention, the disclosure is
illustrative only, and changes may be made in detail, especially in
matters of shape, size, and arrangement of parts within the
principles of the invention to the full extent indicated by the
broad general meaning of the terms in which the appended claims are
expressed.
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