U.S. patent application number 12/579411 was filed with the patent office on 2011-04-21 for support structure for flat-plate heat pipe.
This patent application is currently assigned to ASIA VITAL COMPONENTS CO., LTD.. Invention is credited to Hsiuwei Yang.
Application Number | 20110088873 12/579411 |
Document ID | / |
Family ID | 43878402 |
Filed Date | 2011-04-21 |
United States Patent
Application |
20110088873 |
Kind Code |
A1 |
Yang; Hsiuwei |
April 21, 2011 |
SUPPORT STRUCTURE FOR FLAT-PLATE HEAT PIPE
Abstract
A support structure for flat-plate heat pipe, including a main
body and a fitting body. The fitting body has at least one open
side and a first side section connected with the open side. The
first side section has a capillary structure formed on a periphery
of the first side section. The first side section and the open side
together define a space for fixedly fitting the main body therein.
By means of the capillary structure of the first side section of
the fitting body, the circulating rate of a working fluid flowing
within the flat-plate heat pipe is increased to achieve better heat
dissipation effect and better thermal uniformity.
Inventors: |
Yang; Hsiuwei; (Sinjhuang
City, TW) |
Assignee: |
ASIA VITAL COMPONENTS CO.,
LTD.
Sinjhuang City
TW
|
Family ID: |
43878402 |
Appl. No.: |
12/579411 |
Filed: |
October 15, 2009 |
Current U.S.
Class: |
165/104.26 ;
165/178 |
Current CPC
Class: |
F28D 15/0233 20130101;
F28D 15/046 20130101 |
Class at
Publication: |
165/104.26 ;
165/178 |
International
Class: |
F28D 15/02 20060101
F28D015/02; F28F 9/013 20060101 F28F009/013 |
Claims
1. A support structure for flat-plate heat pipe, comprising: a main
body; and a fitting body having at least one open side and a first
side section connected with the open side, the first side section
having a capillary structure formed on a periphery of the first
side section, the first side section and the open side together
defining a space for fixedly fitting the main body therein.
2. The support structure for flat-plate heat pipe as claimed in
claim 1, wherein the capillary structure is a porous structure in
the form of metal spring, metal mesh or sintered metal powder.
3. The support structure for flat-plate heat pipe as claimed in
claim 1, wherein the periphery of the first side section is
directly formed with channel-shaped or porous capillary
structure.
4. The support structure for flat-plate heat pipe as claimed in
claim 1, wherein the fitting body has the form of a cylindrical
body, a rectangular block or a cubic body.
5. The support structure for flat-plate heat pipe as claimed in
claim 1, wherein the main body is made of a material with high
thermal conductivity.
6. The support structure for flat-plate heat pipe as claimed in
claim 1, wherein the main body is connected to a cover body in
abutment therewith, the cover body including a first flat plate and
a second flat plate corresponding to the first flat plate, the
first and second flat plates defining therebetween a chamber in
which the main body is received and in which a working fluid is
filled.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a flat-plate heat pipe, and
more particularly to an improved support structure for flat-plate
heat pipe including a main body and a fitting body in which the
main body is fitted. The fitting body has a first side formed with
a capillary structure. By means of the capillary structure of the
first side section of the fitting body, the circulating rate of a
working fluid flowing within the flat-plate heat pipe is increased
to achieve better heat dissipation effect and better thermal
uniformity.
BACKGROUND OF THE INVENTION
[0002] Following the rapid progress of industrial technique, there
is a trend in electronic products of miniaturized volume, light
weight, low power consumption, high performance and high
efficiency. Therefore, the working rate of the electronic products
is enhanced and the number of electronic components per unit volume
is increased. During continuous promotion of the performances of
electronic products, the issue of heat dissipation has become more
and more critical. Due to different performances of different
electronic components, the thermal flux is non-uniformly
distributed over the surfaces of the heat-generating electronic
components. Therefore, the so-called "hot spot" will be formed on
the surfaces due to local overheating. The reliability and lifetime
of the electronic components are closely related to the operation
temperature thereof, especially the peripheral components of
compact notebook computers with limited volume. To solve the heat
dissipation problem, various flat-plate heat pipes have been
developed.
[0003] FIG. 1 shows a conventional flat-plate heat pipe composed of
a first copper plate 10 and a second copper plate 11 corresponding
to the first copper plate 10. The first copper plate 10 is
connected with the second copper plate 11 to define a chamber 12 in
which a working fluid (such as water or a liquid) is filled. The
opposite surfaces of the first and second copper plates 10, 11 are
formed with capillary structures 13 enclosing the chamber 12 as
inner wall faces thereof. The capillary structures mainly serve to:
1. reduce thermal flux of the wall faces through liquid membrane
effect; 2. increase boiling core and enlarge evaporation area; and
3. contact with the wall faces to hinder the vapor membrane from
growing. Due to gravity and capillarity, the working fluid is
distributed over the capillary structures 13 in the chamber 12,
(that is, the capillary structures of the first and second copper
plates 10, 11).
[0004] A back surface of the first copper plate 10 distal from the
chamber 12 is in contact with an end face of a heat-generating
component such as a CPU. In this case, the first copper plate 10 is
the so-called evaporating end or heated end for conducting the heat
generated by the heat-generating component to the second copper
plate 11, which is the so-called condensing end to dissipate the
heat. When the heat-generating component generates heat, the first
copper plate 10 absorbs the heat and the working fluid flowing
through the capillary structures 13 is heated to evaporate into
vapor. Thereafter, the vapor quickly flows to the colder portion,
(that is, the second copper plate 11). After the vapor reaches the
second copper plate 11, the vapor will release the latent heat and
change into liquid. The liquid then flows back to the first copper
plate 10 due to the capillary attraction of the capillary
structures 13 of the second copper plate 11 to complete a working
cycle for dissipating the heat. However, there are some problems
with the above structure. That is, the working fluid flowing
through the capillary structures 13 of the first copper plate 10
can be hardly smoothly phase-changed. The problems are as follows:
1. The transformation rate of the working fluid between two phases
is increased with the increment of the transferred heat. However,
the capillary structures have low porosity and low infiltration
rate so that the backflow resistance is increased. In this case, it
is hard to provide sufficient working fluid to go back the
evaporating end. As a result, the heated end of the heat pipe may
dry out to lead to poor heating uniformity and poor heat
dissipation effect. 2. The thermal flux will continuously rise to
result in that the vapor pressure on the liquid level become
greater than the pressure in the liquid. Under such circumstance,
vapor bubbles will be produced in the capillary structures. The
bubbles not only will hinder the working fluid from flowing back,
but also will create a vapor membrane between the heat conduction
face and the capillary structures of the heat pipe with very high
thermal resistance. Due to the vapor membrane, the working fluid
can hardly smoothly phase-change to carry the heat away from the
evaporating end. As a result, the heat will continuously accumulate
at the heated end. In this case, the heated end of the heat pipe
will dry out to lead to poor heating uniformity and poor heat
dissipation effect.
[0005] Please now refer to FIG. 2, which shows a heat pipe vapor
chamber disclosed in Taiwanese Patent No. 443714. Multiple bosses
21 are disposed on the upper plate 20 of the vapor chamber 2. A
capillary structure 23 is disposed on the lower plate 22 in
abutment with the bosses 21 of the upper plate 20 for supporting
the same. The capillary structure 23 serves to guide the condensed
liquid to flow back. The bosses 21 are free from any capillary
structure and are only used to provide support effect. Therefore,
the liquid is simply guided by the capillary structure 23 of the
lower plate 22 to flow back. As a result, the circulating rate of
the fluid is low and the heat dissipation effect is poor.
[0006] According to the aforesaid, the prior art has the following
defects: [0007] 1. The heat dissipation effect is poor. [0008] 2.
The heating uniformity is poor. [0009] 3. The circulating rate of
the fluid is poor.
SUMMARY OF THE INVENTION
[0010] A primary object of the present invention is to provide an
improved support structure for flat-plate heat pipe including a
main body and at least one fitting body. The fitting body has at
least one open side and a first side section connected with the
open side. The first side section has a capillary structure formed
on a periphery of the first side section. The first side section
and the open side together define a space for fixedly fitting the
main body therein. By means of the capillary structure of the first
side section of the fitting body, the circulating rate of a working
fluid flowing within the flat-plate heat pipe is increased to
achieve better heat dissipation effect and better thermal
uniformity.
[0011] A further object of the present invention is to provide the
above support structure for flat-plate heat pipe, which further
includes a cover body connected with the main body. The cover body
includes a first flat plate and a second flat plate in parallel to
the first flat plate. The first and second flat plates define
therebetween a chamber in which the main body is received and in
which a working fluid is filled.
[0012] The main body has a top section, a second side section and a
bottom section opposite to the top section. The top section and the
bottom section respectively abut against the first and second flat
plates. The fitting bodies are stacked and fitted around the main
body. By means of the capillary structure of the first side section
of the fitting body, the circulating rate of a working fluid
flowing within the flat-plate heat pipe is increased to achieve
better heat dissipation effect and better thermal uniformity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The structure and the technical means adopted by the present
invention to achieve the above and other objects can be best
understood by referring to the following detailed description of
the preferred embodiments and the accompanying drawings,
wherein:
[0014] FIG. 1 is a sectional view of a conventional flat-plate heat
pipe;
[0015] FIG. 2 is a sectional view of a conventional heat pipe vapor
chamber;
[0016] FIG. 3 is a perspective view of the fitting body of a first
embodiment of the present invention;
[0017] FIG. 4 is a perspective exploded view of the first
embodiment of the present invention;
[0018] FIG. 5 is a sectional assembled view of the first embodiment
of the present invention;
[0019] FIG. 6 is a perspective view of the fitting bodies of a
second embodiment of the present invention, in which the fitting
bodies are stacked;
[0020] FIG. 7 is a perspective exploded view of the second
embodiment of the present invention; and
[0021] FIG. 8 is a sectional assembled view of the second
embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Please refer to FIGS. 3, 4 and 5. According to a first
embodiment, the support structure for flat-plate heat pipe of the
present invention includes a main body 3 and a fitting body 4. The
fitting body 4 has at least one open side 41 and a first side
section 42 connected with the open side 41. The first side section
42 has a capillary structure 421 formed on a periphery of the first
side section 42. The capillary structure 421 can be a porous
structure in the form of metal spring, metal mesh or sintered metal
powder. The capillary structure 421 has flow-guiding ability and
provides multiple backflow channels. Accordingly, the capillary
structure 421 serves to guide the fluid to quickly flow from the
colder portion back to the heated portion so as to enhance fluid
circulating rate and increase flow amount and prevent the fluid
flowing within the heated portion from drying out. Alternatively,
the periphery of the first side section 42 can be directly formed
with channel-shaped or porous capillary structure 421 for enhancing
attraction, evaporation, condensing and circulating effect.
[0023] The first side section 42 and the open side 41 together
define a space 43 in communication with the open side 41. The main
body 3 can be fixedly fitted into the space 43.
[0024] The fitting body 4 is a hollow body in the form of a
cylindrical body, a rectangular block or a cubic body. In this
embodiment, the fitting body 4 is, but not limited to, a hollow
cylindrical body. in practice, the hollow fitting body has a
configuration adapted to that of the main body. The hollow fitting
body has a first end 411 and a second end 412 extending from the
first end 411. The first and second ends 411, 412 define
therebetween the open side 41.
[0025] Please now refer to FIGS. 3, 4, 5, 6 and 7. The main body 3
is made of a material with high thermal conductivity, such as
copper, silver, aluminum or an alloy thereof. The main body 3
serves to quickly transfer (or conduct) heat from a
high-temperature portion, that is, the heated portion to a
low-temperature portion, that is, the colder portion to dissipate
the heat so as to achieve good thermal uniformity and good heat
dissipation effect. The main body 3 has a top section 31, a bottom
section 32 and a second side section 33. The top section 31 and the
bottom section 32 are respectively flush with the first end 411 and
the second end 412 of the hollow fitting body. In other words, the
main body 3 is fitted in the hollow fitting body with the top
section 31 and the bottom section 32 of the main body 3
respectively flush with the first end 411 and the second end 412 of
the hollow fitting body. In addition, inner side of the first side
section 42 encloses and attaches to a circumference of the second
side section 33.
[0026] Then, the main body 3 is connected to a cover body 5 in
abutment therewith. The cover body 5 is made of a material with
high thermal conductivity, such as copper, silver, aluminum or an
alloy thereof. The cover body 5 includes a first flat plate 51 and
a second flat plate 52 corresponding to the first flat plate 51. A
back end face of the first flat plate 51 distal from the second
flat plate 52 contacts with and attaches to a heat-generating
component such as a CPU (not shown). The back end face of the first
flat plate 51 that contacts with the heat-generating component is
the above-mentioned heated portion (or referred to as an
evaporating end). The second flat plate 52 is the above-mentioned
colder portion (or referred to as a condensing end).
[0027] The first and second flat plates 51, 52 define therebetween
a chamber 53 in which the hollow fitting body and the main body 3
fitted therein are received and in which a certain amount of
working fluid is filled. In this embodiment, the working fluid is,
but not limited to, water. In practice, the working fluid can be
any kind of evaporable fluid such as pure water, inorganic
compound, alcohol, ketone, liquid metal, coolant, organic compound
or a mixture thereof. The main body 3 is disposed in the chamber 53
also for locating and supporting the first and second flat plates
51, 52. The hollow fitting body is fitted around the main body 3 to
increase the contact area (or support area) between the first and
second flat plates 51, 52. Therefore, the strength of the
flat-plate heat pipe is enhanced and the assembling process is
facilitated to lower cost.
[0028] The capillary structure 531 is disposed on inner surface of
the chamber 53. That is, the capillary structure 531 is disposed on
the opposite end faces (the inner surface of the chamber 53) of the
first and second flat plates 51, 52. The working fluid is
distributed over the capillary structure 531 of the first and
second flat plates 51, 52.
[0029] When the heat-generating component generates heat, the
working fluid in the capillary structure 531 of the first flat
plate 51 (the evaporating end) absorbs the heat and phase-changes
from liquid phase working fluid 55 into vapor phase working fluid
56. The vapor phase working fluid 56 will quickly flow across the
chamber 53 to the second flat plate 52 (the condensing end). Also,
part of the heat absorbed by the first flat plate 51 is quickly
conducted through the main body 3 to the second flat plate 52 to
dissipate the heat. After the vapor phase working fluid 56 reaches
the second flat plate 52, the working fluid releases a great amount
of latent heat to further phase-change into the liquid phase
working fluid 55. At this time, the capillary structure 531 of the
second flat plate 52 transfers the liquid phase working fluid 55
back to the first flat plate 51 by means of capillary attraction.
In the meantime, the capillary structure 421 of the first side
section 42 also provides capillary attraction to transfer the
liquid phase working fluid 55 back to the first flat plate 51 in
another path to enhance circulating rate of the working fluid.
Accordingly, the heat is continuously carried away in the cycles to
achieve better thermal uniformity and better heat dissipation
effect.
[0030] FIGS. 6 to 8 show a second embodiment of the present
invention, in which several fitting bodies 4 are stacked and fitted
around the main body 3. To speak more specifically, the fitting
bodies 4 are sequentially fitted around the main body 3 with the
total of the heights of the fitting bodies 4 equal to the height of
the main body 3. In this case, the fitting bodies 4 and the main
body 3 fitted therein are arranged between the first and second
flat plates 51, 52 in abutment therewith. In this embodiment, the
number of the fitting bodies 4 is, but not limited to, three.
Alternatively, there can be four, five, six or more fitting bodies
in accordance with the height of the main body 3. That is, the
number of the fitting bodies 4 is determined by the actual height
of the main body 3.
[0031] According to the aforesaid, the support structure for
flat-plate heat pipe of the present invention has the following
advantages: [0032] 1. The present invention has better heat
dissipation effect. [0033] 2. The present invention has better
thermal uniformity. [0034] 3. The circulating rate of the working
fluid is enhanced and the flow amount is increased. [0035] 4. The
strength is enhanced and the support (contact) area is
enlarged.
[0036] The present invention has been described with some preferred
embodiments thereof and it is understood that many changes and
modifications in the described embodiments can be carried out
without departing from the scope and the spirit of the invention
that is intended to be limited only by the appended claims.
* * * * *