U.S. patent application number 13/851939 was filed with the patent office on 2013-10-03 for heat pipe with grid wick structure having rhombuses.
This patent application is currently assigned to FOXCONN TECHNOLOGY CO., LTD.. The applicant listed for this patent is FOXCONN TECHNOLOGY CO., LTD., FURUI PRECISE COMPONENT (KUNSHAN) CO., LTD.. Invention is credited to SHENG-LIANG DAI, YU-LIANG LO, JIA-HONG WU.
Application Number | 20130255921 13/851939 |
Document ID | / |
Family ID | 49233313 |
Filed Date | 2013-10-03 |
United States Patent
Application |
20130255921 |
Kind Code |
A1 |
DAI; SHENG-LIANG ; et
al. |
October 3, 2013 |
HEAT PIPE WITH GRID WICK STRUCTURE HAVING RHOMBUSES
Abstract
An exemplary heat pipe includes a tube, an evaporation section
and a condenser section located at two opposite ends of the tube, a
grid wick structure received in the tube and abutting an inner wall
of the tube, and a working fluid sealed in the tube. The grid wick
structure includes a plurality of rhombuses. Each rhombus includes
two opposite first included angles, one of the first included
angles is at a point of the rhombus nearest one of the ends of the
tube, the other first included angle is at a point of the rhombus
nearest the other end of the tube. Each first included angle is
smaller than 90 degrees.
Inventors: |
DAI; SHENG-LIANG; (Kunshan,
CN) ; LO; YU-LIANG; (New Taipei, TW) ; WU;
JIA-HONG; (New Taipei, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FURUI PRECISE COMPONENT (KUNSHAN) CO., LTD.
FOXCONN TECHNOLOGY CO., LTD. |
Kunshan
New Taipei |
|
CN
TW |
|
|
Assignee: |
FOXCONN TECHNOLOGY CO.,
LTD.
New Taipei
TW
FURUI PRECISE COMPONENT (KUNSHAN) CO., LTD.
Kunshan
CN
|
Family ID: |
49233313 |
Appl. No.: |
13/851939 |
Filed: |
March 27, 2013 |
Current U.S.
Class: |
165/104.26 |
Current CPC
Class: |
F28D 15/04 20130101;
F28D 15/046 20130101; F28D 15/0233 20130101 |
Class at
Publication: |
165/104.26 |
International
Class: |
F28D 15/04 20060101
F28D015/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 3, 2012 |
CN |
201210095718.4 |
Claims
1. A heat pipe, comprising: a tube, the tube having an evaporation
section and a condenser section located at two opposite ends
thereof; a grid wick structure received in the tube and abutting an
inner wall of the tube, the grid wick structure comprising a
plurality of rhombuses, each rhombus comprising two first included
angles opposite to each other, one of the first included angles
being at a point of the rhombus nearest one of the ends of the
tube, the other first included angle being at a point of the
rhombus nearest the other end of the tube, each first included
angle being smaller than 90 degrees; and a working fluid sealed in
the tube.
2. The heat pipe of claim 1, wherein each rhombus further comprises
two second included angles opposite to each other, a length of an
imaginary line interconnecting vertexes of the two first included
angles being larger than that of an imaginary line interconnecting
vertexes of the two second included angles.
3. The heat pipe of claim 2, further comprising another grid wick
structure with squares, wherein the another grid wick structure
with squares and the grid wick structure with rhombuses are stacked
one on the other.
4. The heat pipe of claim 3, wherein one of the sidelines of the
each square overlaps the imaginary line interconnecting the two
second included angles of a corresponding one of the rhombuses.
5. The heat pipe of claim 1, wherein an imaginary line
interconnecting the two first included angles of each rhombus is
substantially parallel to a longitudinal direction of the tube from
the evaporation section to the condenser section.
6. The heat pipe of claim 1, wherein the wick structure is formed
by weaving wires, and a diameter of each of the wires is in a range
of from 0.03 millimeters to 0.05 millimeters.
7. The heat pipe of claim 1, wherein the first angle is smaller
than 45 degrees.
8. The heat pipe of claim 1, wherein the heat pipe is a flat heat
pipe, and a thickness of the tube from one flat side of the heat
pipe to the other flat side of the heat pipe is smaller than 1.5
millimeters.
9. The heat pipe of claim 1, wherein a length of the sideline of
each rhombus is in the range of from 0.10 millimeters to 0.25
millimeters.
10. A heat pipe, comprising: a tube, the tube having an evaporation
section and a condenser section located at two opposite ends
thereof, the tube defining a longitudinal direction thereof from
the evaporation section to the condenser section; a grid wick
structure received in the tube and abutting an inner wall of the
tube, the grid wick structure being in the form of woven yarn
comprising a first group of lines of yarn each oriented along a
first direction and a second group of lines of yarn each oriented
along a second direction different from the first direction, each
two adjacent lines of the yarn oriented along the first direction
and two corresponding adjacent lines of the yarn oriented along the
second direction cooperatively defining a rhombus, the rhombus
comprising two first included angles opposite to each other, an
imaginary diagonal line interconnecting vertexes of the rhombus
having the two first included angles being substantially parallel
to the longitudinal direction of the tube, each first included
angle being smaller than 90 degrees; and a working fluid sealed in
the tube.
11. The heat pipe of claim 10, wherein each rhombus further
comprises two second included angles opposite to each other, a
length of an imaginary interconnecting the vertexes of the two
first included angles being larger than that of an imaginary
diagonal line interconnecting vertexes of the two second included
angles.
12. The heat pipe of claim 11, further comprising another grid wick
structure with squares, wherein the another grid wick structure
with squares and the grid wick structure with rhombuses are stacked
one on the other.
13. The heat pipe of claim 12, wherein one of the sidelines of each
square overlaps the imaginary line interconnecting the two second
included angles of a corresponding one of the rhombuses.
14. The heat pipe of claim 10, wherein an imaginary line
interconnecting the two first included angles of each rhombus is
substantially parallel to a longitudinal direction of the tube from
the evaporation section to the condenser section.
15. The heat pipe of claim 10, wherein the wick structure is formed
by weaving wires, and a diameter of each of the wires is in a range
of from 0.03 millimeters to 0.05 millimeters.
16. The heat pipe of claim 10, wherein the first included angle is
smaller than 45 degrees.
17. The heat pipe of claim 10, wherein the heat pipe is a flat heat
pipe, and a thickness of the tube from one flat side of the heat
pipe to the other flat side of the heat pipe is smaller than 1.5
millimeters.
18. The heat pipe of claim 10, wherein a length of the sideline of
each rhombus is in the range of from 0.10 millimeters to 0.25
millimeters.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The disclosure relates to heat pipes, and more particularly
to a heat pipe having a grid wick structure made up of
rhombuses.
[0003] 2. Description of the Related Art
[0004] With the continuing development of electronics technology,
many electronic components are nowadays made in a small size but
with a high operating frequency capability. When such electronic
components operate inside a device, a lot of heat is generated and
is required to be dissipated. In order to cool the electronic
components, one or more heat dissipation devices are provided in
the device. Generally, the heat dissipation devices include heat
pipes as heat transferring components.
[0005] A typical heat pipe includes a tube, a mesh wick structure
received in the tube, and a working fluid sealed in the tube. The
wick structure is generally attached on an entire inner wall of the
tube, and thus has the shape of an elongated cylinder. The mesh of
the wick structure is usually comprised of perpendicularly
interlocked strands, with one group of the strands having each
strand aligned along a horizontal direction and another group of
the strands having each strand aligned along a vertical direction.
A wicking efficiency of the wick structure for conducting the
working fluid along the vertical direction is prone to be low. In
some applications, the heat pipe with such a wick structure can not
properly satisfy the requirement of transferring a high amount of
heat from the electronic component(s).
[0006] Therefore, it is desirable to provide a heat pipe with a
wick structure which can solve or at least mitigate the
above-described problems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Many aspects of the disclosure can be better understood with
reference to the drawings. The components in the drawings are not
necessarily drawn to scale, the emphasis instead being placed upon
clearly illustrating the principles of the present heat pipe.
Moreover, in the drawings, all the views are schematic, and like
reference numerals designate corresponding parts throughout the
views.
[0008] FIG. 1 is an abbreviated, plan view of a heat pipe in
accordance with an exemplary embodiment of the disclosure.
[0009] FIG. 2 is an enlarged, cross sectional view of the heat pipe
of FIG. 1, taken along line II-II thereof.
[0010] FIG. 3 is a cross sectional view of part of the heat pipe of
FIG. 2, taken along line III-III thereof, and showing a grid wick
structure having rhombuses.
[0011] FIG. 4 is essentially an enlarged view of two rhombuses of
the grid wick structure of FIG. 3, indicating flow paths of a
working fluid flowing along the grid wick structure.
[0012] FIG. 5 is a cross sectional view of a heat pipe in
accordance with another exemplary embodiment of the disclosure.
[0013] FIG. 6 is an enlarged view of a circled portion VI of the
heat pipe of FIG. 5.
[0014] FIG. 7 is an abbreviated, plan view of a grid wick structure
having a grid with squares, used in the heat pipe of FIG. 5.
[0015] FIG. 8 is essentially an enlarged view of one rhombus of a
grid wick structure having a grid with rhombuses, also used in the
heat pipe of FIG. 5, indicating flow paths of a working fluid
flowing along the grid wick structure.
DETAILED DESCRIPTION
[0016] Referring to FIG. 1 through FIG. 3, a heat pipe 100 in
accordance with an exemplary embodiment is shown. The heat pipe 100
includes a tube 10, a grid wick structure 20 received in the tube
10, and a working fluid 30 (see FIG. 4) sealed in tube 10. The heat
pipe 100 includes an evaporation section 11 and a condenser section
12 located at two opposite ends of the tube 10. In this embodiment,
the heat pipe 100 is a flat heat pipe.
[0017] The tube 10 is made of material with good heat
conductibility, such as copper. The tube 10 is hollow and flat, and
the tube 10 is formed by deforming (i.e. flattening) a circular
tube. The tube 10 includes a top plate 13, a bottom plate 14, and
two side plates 15. The top plate 13 is parallel with the bottom
plate 14. The two side plates 15 are arc-shaped, and respectively
interconnect the top plate 13 and the bottom plate 14. A thickness
of the tube 10, i.e., a distance between a topmost extremity of the
top plate 13 and a bottommost extremity of the bottom plate 14, is
smaller than 1.5 millimeters (mm).
[0018] The grid wick structure 20 abuts an inner wall of the tube
10. In the illustrated embodiment, the grid wick structure 20 is in
contact with the inner wall of the tube 10. The grid wick structure
20 extends from the evaporation section 11 to the condenser section
12. The grid wick structure 20 is formed by weaving (or meshing)
linear material (e.g. strands or yarn) such as copper wire,
stainless steel wire, fiber, and so on. Preferably, the grid wick
structure 20 in this embodiment is formed by weaving wires, with
each wire having a diameter in the range of from about 0.03 mm to
about 0.05 mm.
[0019] Referring to FIGS. 3-4, the grid wick structure 20 includes
a multiplicity of rhombuses 21. The rhombuses 21 provide capillary
force to drive the working fluid 30 to flow from the condenser
section 12 back to the evaporation section 11. The rhombuses 21 are
all identical to each other. Each rhombus 21 includes four
equilateral sidelines 213, and the rhombuses 21 are arranged
uniformly from the evaporation section 11 to the condenser section
12. The sidelines 213 of the rhombuses 21 correspond to the linear
material (e.g. wires) that make up the grid wick structure 20.
[0020] Specifically, a length of the sideline 213 of each rhombus
21 is in the range of from about 0.10 mm to about 0.25 mm. Each
rhombus 21 includes two first angles 211 opposite to each other and
two second angles 212 opposite to each other. Each first angle 211
is smaller than 90 degrees, and a diagonal line (not shown)
interconnecting vertexes of the two first angles 211 is
substantially parallel to a longitudinal direction of the tube 10
from the evaporation section 11 to the condenser section 12.
Correspondingly, each second angle 212 is larger than 90 degrees
and smaller than 180 degrees. A length of the line interconnecting
the vertexes of the two first angles 211 is larger than that of a
diagonal line (see FIG. 8) interconnecting vertexes of the two
second angles 212.
[0021] In this embodiment, the two first angles 211 are smaller
than 45 degrees, and the two second angles 212 are larger than 135
degrees. Correspondingly, a flow path of the working fluid 30
travelling from the condenser section 12 back to the evaporation
section 11 is restricted to be in an optimal range. In particular,
a flow resistance of the working fluid 30 moving along directions
parallel to the line interconnecting the vertexes of the two second
angles 212 is restricted to be in a lowest range. This helps
prevent backflow from occurring.
[0022] When the heat pipe 100 works, the evaporation section 11 of
the tube 10 contacts a heat source. The working fluid 30 absorbs
heat from the evaporation section 11, becomes vaporized, flows to
the condenser section 12 and thereby conveys the heat to the
condenser section 12, and releases the heat at the condenser
section 12 and thereby becomes liquefied. The grid wick structure
20 provides capillary force to drive the liquefied working fluid 30
at the condenser section 12 to flow back to the evaporation section
11 along the sidelines 213 of the rhombuses 21. In this way, the
working fluid 30 moves in the tube 10 in a circulatory manner to
transfer heat generated by operation of one or more electronic
components from the evaporation section 11 to the condenser section
12 of the heat pipe 100. In this embodiment, the working fluid 30
is material with a low boiling point, such as water, methanol,
alcohol, and so on.
[0023] Referring to FIG. 4, this illustrates how the rhombuses 21
of the grid wick structure 20 are advantageous. When the working
fluid 30 flows along two consecutive sidelines 213 of any of the
rhombuses 21, the total length of the path traversed is shorter
than that of two consecutive sidelines of a corresponding square
(shown in dashed lines in FIG. 4 for illustration). That is, the
liquefied working fluid 30 flows along a relatively short path.
Furthermore, because the second angle 212 is larger than 90
degrees, when the working fluid 30 travels from one trailing
sideline 213 to the adjacent leading sideline 213 of any of the
rhombuses 21, the working fluid 30 need only negotiate a gentler
bend compared to that of two consecutive sidelines of a
corresponding square (shown in dashed lines in FIG. 4). In
particular, in the grid wick structure 20, the bend requiring
negotiation corresponds to the obtuse second angle 212, which
represents a gentler angle compared with the right-angle bend of
the corresponding square. For these reasons, the working fluid 30
sealed in the tube 10 can circulate quickly with low resistance and
minimal or no backflow.
[0024] Referring to FIG. 5 through FIG. 8, a heat pipe 200 in
accordance with another exemplary embodiment is shown. The
difference between the heat pipe 200 and the heat pipe 100 is that
the heat pipe 200 includes a grid wick structure 201 with squares
22 and another grid wick structure 202 with rhombuses 23. The two
grid wick structures 201, 202 are stacked one on the other. The
squares 22 partly coincide with the rhombuses 23, such that the
squares and rhombuses 22, 23 support each other. Each square 22
includes four equal sidelines 223. Preferably, in this embodiment,
each rhombus 23 corresponds in size to two squares 22. One of the
sidelines 223 of each square 22 overlaps with the line
interconnecting the two second angles 212 of a corresponding one of
the rhombus 23. The intersection point of the two sidelines 213 at
each second angle 212 of each rhombus 23 coincides with the
intersection point of two corresponding sidelines 223 of each of
four corresponding squares 22. The intersection point of the two
sidelines 213 at each first angle 211 of each rhombus 23 coincides
with the center point of a sideline 223 of each of two
corresponding squares 22.
[0025] Referring to FIG. 8, the working fluid 30 travelling from
position A to position B is taken as an example to show the
difference between the functioning of the grid wick structure 201
and the grid wick structure 202, and the benefit of providing both
the grid wick structures 201, 202 stacked together. FIG. 8 and the
following description also serve to illustrate differences between
the functioning of both heat pipes 100, 200 and the above-described
traditional heat pipe.
[0026] In the traditional square 22 alone, when the working fluid
30 travels from position A to position B, the working fluid 30 must
traverse two 90-degree bends along three corresponding sidelines
223 of the square 22. The total length of the path traveled is the
length of two sidelines 223. In contrast, with the heat pipe 200
having the squares 22 stacked with the rhombuses 23, part of the
flow path of the working fluid 30 can be along one of the sidelines
213 of the rhombus 21 to reach position B. Thus the total length of
the path traveled from position A to position B is shorter. In this
way, for the heat pipe 200, the flow path of the working fluid 30
from the condenser section 12 to the evaporation section 11 is
shortened.
[0027] In addition, because the rhombuses 23 and the squares 22 are
stacked together in the manner described above such that the
squares 22 partly coincide with the rhombuses 23 and the squares
and rhombuses 22, 23 support each other, the working fluid 30
conduct heats evenly along the tube 10. As a result, a heat
transfer evenness of the heat pipe 200 is stable, and a heat
transfer efficiency of the heat pipe 200 is improved.
[0028] All in all, one grid wick structure 20, 202 with rhombuses
21, 23 is received in the heat pipe 100, 200, respectively. When
the working fluid 30 flows along two consecutive sidelines 213 of
any of the rhombuses 21, 23, the total length of the path traversed
is shorter than that of two consecutive sidelines of a
corresponding square (shown in dashed lines in FIG. 4). The
liquefied working fluid 30 flows from the condenser section 12 to
the evaporation section 11 along a path that is as much as, or even
more than, 19% shorter than that of a conventional heat pipe.
[0029] Because the first angle 211 is smaller than 90 degrees and
the second angle 212 is greater than 90 degrees, when the working
fluid 30 flows between the two consecutive sidelines 213 of any of
the rhombuses 21, 23, the working fluid 30 only needs to negotiate
the gentle angle between the two consecutive sidelines 213. Thus
the working fluid 30 can travel easily and evenly from the
condenser section 12 to the evaporation section 11. In addition,
the flow resistance of the working fluid 30 moving along directions
parallel to the line interconnecting the vertexes of the two second
angles 212 of each rhombus 21, 23 is restricted to be in a lowest
range. This helps prevent backflow from occurring.
[0030] It is to be understood that the above-described embodiments
are intended to be illustrative rather than limiting. Variations
may be made to the embodiments without departing from the spirit of
the disclosure. The above-described embodiments illustrate the
scope of the disclosure but do not restrict the scope of the
disclosure.
* * * * *