U.S. patent application number 13/101180 was filed with the patent office on 2012-11-08 for flat-type heat pipe and wick structure thereof.
This patent application is currently assigned to CELSIA TECHNOLOGIES TAIWAN, I. Invention is credited to Chieh-Ping Chen, Te-Hsuan Chin, George Anthony Meyer, IV, Chien-Hung Sun.
Application Number | 20120279687 13/101180 |
Document ID | / |
Family ID | 47089453 |
Filed Date | 2012-11-08 |
United States Patent
Application |
20120279687 |
Kind Code |
A1 |
Meyer, IV; George Anthony ;
et al. |
November 8, 2012 |
FLAT-TYPE HEAT PIPE AND WICK STRUCTURE THEREOF
Abstract
The present invention provides a flat-type heat pipe and a wick
structure thereof. The flat-type heat pipe has a flat tube. The
wick structure is arranged inside the flat tube along an axial line
of the flat tube. The wick structure comprises a first wick portion
and two second wick portions connected on both sides of the first
wick portion. The thickness of the first wick portion is larger
than that of the second wick portion. The first wick portion abuts
against an upper inner wall of the flat tube. An air channel is
formed between each of the second wick portions and the upper inner
wall of the flat tube. The wick structure supports the inner wall
of the flat-type heat pipe without providing additional supporting
structure, so that the heat pipe can be made more compact.
Inventors: |
Meyer, IV; George Anthony;
(Morgan Hill, CA) ; Sun; Chien-Hung; (Zhongli
City, TW) ; Chen; Chieh-Ping; (Zhongli City, TW)
; Chin; Te-Hsuan; (Zhongli, TW) |
Assignee: |
CELSIA TECHNOLOGIES TAIWAN,
I
|
Family ID: |
47089453 |
Appl. No.: |
13/101180 |
Filed: |
May 5, 2011 |
Current U.S.
Class: |
165/104.26 |
Current CPC
Class: |
F28D 15/046
20130101 |
Class at
Publication: |
165/104.26 |
International
Class: |
F28D 15/04 20060101
F28D015/04 |
Claims
1. A flat-type heat pipe, configured to perform heat exchange with
a heat source and including: a flat tube having a lower surface
brought into thermal contact with the heat source; a working fluid
filled in the flat tube; and a wick structure arranged inside the
flat tube along an axial line of the flat tube, the wick structure
comprising a first wick portion and two second wick portions
connected on both sides of the first wick portion, the thickness of
the first wick portion being larger than that of the second wick
portion, the first wick portion abutting against an upper inner
wall of the flat tube, an air channel being formed between each of
the second wick portions and the upper inner wall of the flat
tube.
2. The flat-type heat pipe according to claim 1, wherein the wick
structure is made of sintered metal powder, the first wick portion
and the two second wick portions are connected to a lower inner
wall of the flat tube.
3. The flat-type heat pipe according to claim 2, wherein the width
of the first wick portion covers a region on both sides of a
central axial line of the flat tube to support the region on both
sides of the central axial line of the flat tube, the width of the
first wick portion is larger than the width of the second wick
portion.
4. The flat-type heat pipe according to claim 3, wherein the width
of the wick structure is equal to that of the heat source.
5. A wick structure of a flat-type heat pipe, the flat-type heat
pipe having a flat tube, the wick structure being arranged inside
the flat tube along an axial line of the flat tube, characterized
in that: the wick structure comprises a first wick portion and two
second wick portions connected on both sides of the first wick
portion, the thickness of the first wick portion is larger than
that of the second wick portion, the first wick portion abut
against an upper inner wall of the flat tube, an air channel is
formed between each of the second wick portions and the upper inner
wall of the flat tube.
6. The wick structure of a flat-type heat pipe according to claim
5, wherein a lower surface of the flat tube is brought into thermal
contact with a heat source, the wick structure is made of sintered
metal powder, the first wick portion and the two second wick
portions are connected to a lower inner wall of the flat tube.
7. The wick structure of a flat-type heat pipe according to claim
6, wherein the width of the first wick portion covers a region on
both sides of a central axial line of the flat tube to support the
region on both sides of the central axial line of the flat tube,
the width of the first wick portion is larger than the width of the
second wick portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a heat pipe, in particular
to a flat-type heat pipe and a wick structure thereof.
[0003] 2. Description of Prior Art
[0004] With the advancement of science and technology, electronic
products and electronic elements are made more and more compact.
Thus, heat pipes associated with these compact electronic products
and electronic elements have to be made compact accordingly.
According to the existing level in this art, a heat pipe whose
thickness is smaller than 2 mm is referred to as a "super-thin heat
pipe", and a heat pipe whose thickness is larger than 2 mm is
referred to as a "thin heat pipe".
[0005] However, according to the existing level in this art, the
manufacture of thin heat pipes and super-thin heat pipes encounters
problems as follows. Since the thin heat pipe or the super-thin
heat pipe has a flat tube, the thickness of the flat tube is
required to be small enough to manufacture a standard thin heat
pipe or super-thin heat pipe. Thus, if a supporting structure is
provided in the flat tube, the thickness of the supporting
structure may inevitably increase the thickness of the thin heat
pipe or the super-thin heat pipe, so that the thin heat pipe or the
super-thin heat pipe cannot be made compact sufficiently. On the
other hand, if the interior of the flat tube is not provided with a
supporting structure, the strength of the flat tube is insufficient
and may be recessed due to the external atmospheric pressure.
[0006] Therefore, it is an important issue for the present Inventor
to solve the above-mentioned problems.
SUMMARY OF THE INVENTION
[0007] The present invention is to provide a flat-type heat pipe,
in which a wick structure is provided to support inner walls of the
flat-type heat pipe. By this wick structure, it is unnecessary to
provide an additional supporting structure, so that the flat-type
heat pipe can be made more compact.
[0008] The present invention is to provide a flat-type heat pipe,
in which a wick structure is provided. The wick structure can be
manufactured easily and provide a path for allowing vapor-phase and
liquid-phase working fluid to flow therein smoothly, thereby
generating a good effect on heat conduction and liquid reflow.
[0009] The present invention provides a flat-type heat pipe,
configured to perform heat exchange with a heat source and
including:
[0010] a flat tube having a lower surface brought into thermal
contact with the heat source;
[0011] a working fluid filled in the flat tube; and
[0012] a wick structure arranged inside the flat tube along an
axial line of the flat tube, the wick structure comprising a first
wick portion and two second wick portions connected on both sides
of the first wick portion, the thickness of the first wick portion
being larger than that of the second wick portion, the first wick
portion abutting against an upper inner wall of the flat tube, an
air channel being formed between each of the second wick portions
and the upper inner wall of the flat tube.
[0013] The present invention is to provide a wick structure of a
flat-type heat pipe, which is configured to support the inner walls
of the flat-type heat pipe. By this structure, it is unnecessary to
provide an additional supporting structure, so that the flat-type
heat pipe can be made more compact.
[0014] The present invention is to provide a wick structure of a
flat-type heat pipe, which can be manufactured easily and provide a
path for allowing vapor-phase and liquid-phase working fluid to
flow therein smoothly, thereby generating a good effect on heat
conduction and liquid reflow.
[0015] The present invention provides a wick structure of a
flat-type heat pipe, the flat-type heat pipe having a flat tube,
the wick structure being arranged inside the flat tube along an
axial line of the flat tube, characterized in that:
[0016] The wick structure comprises a first wick portion and two
second wick portions connected on both sides of the first wick
portion, the thickness of the first wick portion is larger than
that of the second wick portion, the first wick portion abuts
against an upper inner wall of the flat tube, an air channel is
formed between each of the second wick portions and the upper inner
wall of the flat tube.
[0017] In comparison with prior art, the present invention has
advantageous features as follows.
[0018] The wick structure of the present invention comprises a
first wick portion and two second wick portions connected on both
sides of the first wick portion. The thickness of the first wick
portion is larger than that of the second wick portion. The first
wick portion abuts against an upper inner wall of the flat tube.
Thus, the first wick portion is configured to support the upper
inner wall of the flat tube. As a result, it is unnecessary to
provide another additional supporting structure in the flat tube,
so that the flat-type heat pipe can be made more compact. Since the
inner walls of the flat tube are supported by the first wick
portion, the flat tube will not be recessed due to the external
atmospheric pressure.
[0019] Further, since the wick structure of the present invention
comprises a first wick portion and two second wick portions
connected on both sides of the first wick portion, the wick
structure of the present invention is configured to expand
laterally from the axial line of the flat tube with a larger area.
As a result, more working fluid exists in the expanded wick
structure to absorb the heat of the heat source for evaporation. On
the other hand, more liquid-phase working fluid flows back by means
of the expanded wick structure, thereby generating a larger
heat-conducting efficiency.
[0020] Further, according to the present invention, an air channel
is formed between each of the second wick portions and the upper
inner wall of the flat tube. The vapor-phase working fluid can
quickly flow toward the other end of the heat pipe away from the
heat source via the air channels and the smooth inner walls of the
flat tube, thereby generating a rapid heat-conducting effect.
BRIEF DESCRIPTION OF DRAWING
[0021] FIG. 1 is a perspective view of the present invention;
[0022] FIG. 2 is a side cross-sectional view of the present
invention before being pressed flat; and
[0023] FIG. 3 is a side cross-sectional view of the present
invention after being pressed flat.
DETAILED DESCRIPTION OF THE INVENTION
[0024] 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.
[0025] Please refer to FIGS. 1 to 3. The present invention provides
a wick structure of a flat-type heat pipe. The flat-type heat pipe
1 has a flat tube 10. The wick structure 20 is arranged inside the
flat tube 10 along an axial line of the flat tube 10. The wick
structure 20 is made by sintered metal powder.
[0026] The manufacturing procedure of the present invention will be
described as follows.
[0027] First, a circular tube 10a is provided, which has smooth
inner walls. Then, a core rod (not shown) is inserted into the
circular tube 10a. The outer diameter of the core rod is smaller
than the inner diameter of the circular tube 10a. The profile of
the upper portion of the core rod corresponds to the profile of the
inner wall of the circular tube 10a. The profile of the lower
portion of the core rod forms three edges, so that a gap can be
formed between the core rod and the inner wall of the circular tube
10a. Metal powder is filled into the gap between the inner wall of
the circular tube 10a and the core rod, thereby forming a
construction shown in FIG. 2. The profile of the lower portion of
the core rod makes the metal powder to be shaped as a first wick
portion 21 and two second wick portions 22 connected on both sides
of the first wick portion 21. It can be seen from FIG. 2 that, the
thickness and width of the first wick portion 21 are larger than
those of the second wick portion 22. The width of the first wick
portion 21 covers a region on both sides of the axial portion of
the flat tube 10 and is almost one half of the width of the flat
tube 10. In other words, the first wick portion 21 supports the
region on both sides of the axial portion of the flat tube 10.
[0028] Next, the circular tube 10a filled with the core rod and the
metal powder is sintered to form a porous wick structure 20. Then,
the core rod is drawn out of the circular tube 10a. When the wick
structure 20 is still plastic, a pressing die (not shown) is used
to press the circular tube 10a, so that the circular tube 10a shown
in FIG. 2 is pressed to become a flat tube 10 shown in FIG. 3.
[0029] It should be further noted that the present inventor has
taken practical demands into consideration. More specifically, a
lower surface 11 of the flat tube 10 is brought into thermal
contact with a heat source (not shown). Thus, as shown in FIG. 2,
the metal powder is filled in the lower portion (rather than the
upper portion) of the circular tube 10a, and then the metal powder
is set by the core rod. After the circular tube 10a shown in FIG. 2
is pressed to form the flat tube 10 shown in FIG. 3, the upper
inner wall of the circular tube 10a is compressed, so that the
upper inner wall 12 of the flat tube 10 abuts against the first
wick portion 12 and is supported thereby. At this time, the second
wick portion 21 is subjected to a deformation and adhered to the
lower inner wall 13 of the flat tube 10, thereby expanding
laterally. Due to the specific profile of the core rod, the
thickness and width of the second wick portion 22 are smaller than
those of the first wick portion 21. Even though the upper inner
wall 12 of the flat tube 10 has abut against the first wick portion
21, a distance still exists between the upper inner wall 12 of the
flat tube 10 and the second wick portion 22, thereby forming an air
channel 30.
[0030] The operating principle and advantages of the present
invention will be described as follows.
[0031] Please refer to FIGS. 1 and 3. At one end of the flat tube
10, the lower surface 11 of the flat tube 10 is brought into
thermal contact with a heat source (not shown). The end of the flat
tube 10 contacting the heat source is referred to as a
heat-absorbing end, and the other end of the flat tube 10 away from
the heat source is referred to as a heat-releasing end. Since the
lower surface 11 of the flat tube 10 is brought into thermal
contact with the heat source and the wick structure 20 is arranged
on the lower inner wall 13 of the flat tube 10, the working fluid
(not shown) in the wick structure 20 can sufficiently absorb the
heat of the heat source for evaporation.
[0032] The vapor-phase working fluid has a small density, so that
it will float in the air channel 30 formed between the second wick
portion 22 and the upper inner wall 12 of the flat tube 10. Since
the inner walls of the flat tube 10 are smooth, the vapor-phase
working fluid can rapidly flow from the heat-absorbing end toward
the heat-releasing end. The vapor-phase working fluid reaching the
heat-releasing end condenses to become liquid-phase working fluid.
The liquid-phase working fluid naturally descends due to gravity
force to flow into the wick structure 20. Since the wick structure
20 is arranged on the lower inner wall 13 of the flat tube 10, the
liquid-phase working fluid can rapidly flow back to the
heat-absorbing end along the expanded wick structure 20, thereby
generating an excellent effect on heat conduction and liquid
reflow. In this way, the dry-out phenomenon of the heat-absorbing
end can be avoided. That is to say, since the wick structure 20 of
the present invention comprises a first wick portion 21 and two
second wick portions 22 connected on both sides of the first wick
portion 21, the wick structure 20 of the present invention is
configured to expand laterally from the axial line of the flat tube
10 with a larger area. As a result, more working fluid exists in
the expanded wick structure 20 to absorb the heat of the heat
source for evaporation. On the other hand, more liquid-phase
working fluid flows back by means of the expanded wick structure
20, thereby generating a larger heat-conducting efficiency.
[0033] The wick structure 20 of the present invention comprises a
first wick portion 21 and two second wick portions 22 connected on
both sides of the first wick portion 21. The thickness and width of
the first wick portion 21 are larger than those of the second wick
portion 22. The first wick portion 21 abuts against the upper inner
wall 12 of the flat tube 10. Thus, the first wick portion 21 is
configured to support the upper inner wall 12 of the flat tube 10.
As a result, it is unnecessary to provide another additional
supporting structure in the flat tube 10, so that the flat-type
heat pipe 1 can be made more compact. Since the inner walls of the
flat tube 10 are supported by the first wick portion 21, the flat
tube 10 will not be recessed due to the external atmospheric
pressure.
[0034] It should be further noted that, preferably, the width of
the wick structure 20 corresponds to the width of the heat source.
For example, if the width of the heat source is 10 mm, the width of
the wick structure 20 may be 10 mm, so that the width of the wick
structure 20 can be completely used for heat conduction. Thus, if
the width of the flat tube 10 is 25 mm, the wick structure 20 is
substantially located in the region near the axial line of the flat
tube 10.
[0035] Although the present invention has been described with
reference to the foregoing preferred embodiment, 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.
* * * * *