U.S. patent application number 10/118970 was filed with the patent office on 2003-10-16 for micro-loop heat pipe.
This patent application is currently assigned to MEMFUEL INTERNATIONAL CORPORATION. Invention is credited to Wu, Wen-Kuang.
Application Number | 20030192669 10/118970 |
Document ID | / |
Family ID | 28789892 |
Filed Date | 2003-10-16 |
United States Patent
Application |
20030192669 |
Kind Code |
A1 |
Wu, Wen-Kuang |
October 16, 2003 |
Micro-loop heat pipe
Abstract
A MICRO-LOOP HEAT PIPE, under the condition of no additional
acting-force, removes the waste heat from the devices needed
heat-dissipation to the well heat-dissipating circumstance by
flexible contact. The MICRO-LOOP HEAT PIPE comprising: at least a
flexible metal film, which forms a closed space in which fluid may
circulate, and has a heat-absorbing zone and a heat-dissipating
zone that both are connected by flow path; at least a wick
structure by metal net, which is a flexible structure arranged in
the heat-absorbing zone, and in which the transferred-into heat may
be conducted uniformly; and a working fluid, may be filled into the
flexible metal film, absorbs heat in the heat-absorbing zone,
vaporizes into gas state, and generates a pressure source that may
make the working fluid circulate inside the flexible metal film;
the gasified working fluid may be cooled (or heat-dissipated) in
the heat-dissipating zone and changed back to liquid state.
Inventors: |
Wu, Wen-Kuang; (YangMei
Town, TW) |
Correspondence
Address: |
DOUGHERTY & TROXELL
SUITE 1404
5205 LEESBURG PIKE
FALLS CHURCH
VA
22041
US
|
Assignee: |
MEMFUEL INTERNATIONAL
CORPORATION
|
Family ID: |
28789892 |
Appl. No.: |
10/118970 |
Filed: |
April 10, 2002 |
Current U.S.
Class: |
165/46 ;
165/104.26 |
Current CPC
Class: |
F28D 2015/0225 20130101;
F28D 15/0241 20130101; F28D 15/0266 20130101 |
Class at
Publication: |
165/46 ;
165/104.26 |
International
Class: |
F28F 007/00; F28D
015/00 |
Claims
What is claimed is:
1. A MICRO-LOOP HEAT PIPE, under the condition of no additional
acting-force, removes the waste heat from the devices needed
heat-dissipation to the well heat-dissipating circumstance by
flexible contact, the MICRO-LOOP HEAT PIPE comprising: at least a
flexible metal film, which forms a closed space in which fluids may
circulate, and has a heat-absorbing zone and a heat-dissipating
zone that both are connected by flow path; at least a wick
structure by metal net, which is a flexible structure arranged in
the heat-absorbing zone, and in which the transferred-into heat may
be conducted uniformly; and, a working fluid, may be filled into
the flexible metal film, absorbs heat in the heat-absorbing zone,
vaporizes into gas state, and generates a pressure source that may
make the working fluid circulate inside the flexible metal film;
the gasified working fluid may be cooled (or heat-dissipated) in
the heat-dissipating zone and changed back to liquid state.
2. The MICRO-LOOP HEAT PIPE of the claim 1, wherein the
heat-dissipating zone of the flexible metal film has a structure of
"S" shape that is applied for elongating the flow path of the
working fluid within the heat-dissipating zone for enhancing the
efficiency of heat-dissipation.
3. The MICRO-LOOP HEAT PIPE of the claim 1, wherein the material of
the flexible metal film is a material of high heat-conductance and
at least one of silver, copper, and aluminum, etc.
4. The MICRO-LOOP HEAT PIPE of the claim 1, wherein the material of
the metal net structure is a material of high heat-conductance and
at least one of silver, copper, and aluminum, etc.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a MICRO-LOOP HEAT PIPE,
under the condition of no additional acting-force, removes the
waste heat from the devices needed heat-dissipation to the well
heat-dissipating circumstance by flexible contact.
BACKGROUND OF THE INVENTION
[0002] In the developing trends of lightness, thinness, shortness,
and smallness for hi-tech products, the solution for the problem of
heat dissipation becomes more and more important.
[0003] In the prior arts, the desktop computer is arranged with a
fan in the CPU by applying air to cool it. However, in a limited
space, above problem needs another structure to solve the problem
of insufficient room for arranging a fan. For example, the heat
dissipation of CPU of laptop computer, due to the limitation of
space, is different from the fan arranged in the CPU of the desktop
computer. In the prior arts for CPU's heat-dissipation of laptop
computer, an application of heat-dissipating tube is used. One end
of the heat-dissipating tube is a heat-absorbing end that absorbs
the waste heat of the CPU. Another end is a heat-dissipating end,
of which height is higher than the absorbing end. A working fluid
of low boiling point is contained in the heat-dissipating tube. The
working fluid is heated and become gas state by the
heat-dissipating end of the heat-dissipating tube receiving the
dissipated heat from the CPU. The gasified working fluid then
floats up to the other cooling end of the heat-dissipating tube.
The cooling end is usually arranged in the back portion of the LCD
where the ventilation is good, or it is arranged on the machine
shell. The gasified working fluid is cooled therein and changed
from gas state back to liquid state. The liquidized working fluid
is then flowed back to the heat-absorbing end by the operation of
gravity and completes a heat-fluid circulation. By this manner of
heat-fluid circulation, the CPU's heat is continuously dissipated
out to the atmosphere.
[0004] In above-described structure, although it is simple, but a
working fluid of two phases (i.e. liquid state and gas state)
co-existing simultaneously in a tube body becomes a liquid-gas
mixture that makes the volume of filled liquid become an important
factor. Since it is impossible to control the behavior between the
phases of liquid and gas, so the most quantity of removable heat is
around 20.about.25 W.
[0005] For another heat-dissipating device in the prior arts, it is
a closed metal structure containing working fluid. A circulating
path is formed inside the heat-dissipating device, and which
includes a heat-absorbing zone and a heat-dissipating zone.
Wherein, the heat-absorbing zone is arranged with a wick
manufactured by the method of powder metallurgy. Furthermore, the
function of the wick is to increase the heat-absorbing area of the
heat-absorbing zone. The working fluid absorbs heat in the
heat-absorbing zone, and then inflates into gas state. The working
fluid of liquid state is pushed toward the heat-absorbing zone by
the pressure. The working fluid of gas state is cooled in the
heat-dissipating zone, and then condensed into liquid state. And,
again the working fluid of liquid state is pushed by the pressure
toward the heat-absorbing zone and a heat-fluid circulation is
generated.
[0006] However, since the wick is made by the method of powder
metallurgy, so it is impossible to control the behavior of the flow
field inside the wick and to make a mass production. Furthermore,
the wick made by the method of powder metallurgy has no
flexibility. Therefore, the entire system is formed by the
traditional method of pipe welding, so the manufacturing cost is
very high.
SUMMARY OF THE INVENTION
[0007] The main object of the present invention is to provide a
MICRO-LOOP HEAT PIPE, of which metal net structure may be designed
and manufactured as a wick by the connection technology of micro
electric mechanic system (MEMS). It is also possible to make mass
production and control the flow field behavior inside the wick. The
wick is flexible and its geometric size is variable. The entire
system is also a flexible structure and it is formed by the
connection technology of the micro electric mechanic system (MEMS).
The elements or devices required by the flexible contact may
increase the efficiency of heat transfer, increase the reliability
of manufacture, and reduce the cost of manufacture.
[0008] In order to fulfill above-mentioned objects, a MICRO-LOOP
HEAT PIPE has been invented. Under the condition of no additional
acting-force, it may remove the waste heat from the devices needed
heat-dissipation to the well heat-dissipating circumstance by
flexible contact. The MICRO-LOOP HEAT PIPE comprising: at least a
flexible metal film, at least a wick structure by metal net, and a
working fluid.
[0009] The flexible metal film forms a closed space in which fluids
may circulate, and has a heat-absorbing zone and a heat-dissipating
zone that both are connected by flow path.
[0010] The metal net structure is a flexible structure arranged in
the heat-absorbing zone, and in which the transferred-into heat may
be conducted uniformly. And,
[0011] The working fluid, may be filled into the flexible metal
film, absorbs heat in the heat-absorbing zone, vaporizes into gas
state, and generates a pressure source that may make the working
fluid circulate inside the flexible metal film. The gasified
working fluid may be cooled (or heat-dissipated) in the
heat-dissipating zone and changed back to liquid state.
[0012] In order to more clearly describe the operation principle of
the MICRO-LOOP HEAT PIPE proposed in the present invention,
detailed description in cooperation with corresponding drawings are
presented as following.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is an illustration of action principle of the
MICRO-LOOP HEAT PIPE of the present invention.
[0014] FIG. 2 is a cross-sectional view of A-A line in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention is mainly to provide a MICRO-LOOP HEAT
PIPE, of which metal net structure may be designed and manufactured
as a wick by the connection technology of micro electric mechanic
system (MEMS). It is also possible to make mass production and
control the flow field behavior inside the wick. The wick is
flexible and its geometric size is variable. The entire system is
also a flexible structure and it is formed by the connection
technology of the micro electric mechanic system (MEMS). The
elements or the devices required by the flexible contact may
increase the efficiency of heat transfer, increase the reliability
of manufacture, and reduce the cost of manufacture.
[0016] The action principle and structure of the invention are
described as following. Please refer to FIG. 1 and FIG. 2, which
show a MICRO-LOOP HEAT PIPE of the invention, under the condition
of no additional acting-force, removes the waste heat from the
devices needed heat-dissipation to the well heat-dissipating
circumstance by flexible contact. The MICRO-LOOP HEAT PIPE
includes: at least a flexible metal film 1, at least a wick
structure by metal net 2, and a working fluid 3. The flexible metal
film 1 forms a closed space in which fluids may circulate, and has
a heat-absorbing zone 11 and a heat-dissipating zone 12 that both
are connected by flow path 13.
[0017] The metal net structure 2 is a flexible structure arranged
in the heat-absorbing zone 11, and in which the transferred-into
heat may be conducted uniformly. Also, the metal net structure 2
may be firstly constructed as a flat plane net that is connected by
metal threads of same or different thread radius in the way of
diffusion bonding. Secondly, the flat plane net is connected
upwardly by the manner of diffusion bonding to be formed as a
three-dimensional net. And,
[0018] The working fluid 3, may be filled into the flexible metal
film 1 absorbs heat in the heat-absorbing zone 11, vaporizes into
gas state, and generates a pressure source that may make the
working fluid 3 circulate inside the flexible metal film 1. The
gasified working fluid 3 may be cooled (or heat-dissipated) in the
heat-dissipating zone 12 and changed back to liquid state. Wherein,
when the working fluid 3 is filled into the flexible metal net 1,
it can depend on the requirement of practical application and the
pressure cooperating with flow path 13 to replace different kind of
working fluid 3 in expectation to reach an optimal effect of
heat-dissipation.
[0019] Preferably, the heat-dissipating zone 12 of the flexible
metal film 1 has a structure of "S" shape that is applied for
elongating the flow path of the working fluid 3 within the
heat-dissipating zone 12 for enhancing the efficiency of
heat-dissipation.
[0020] The material for above-described metal net structure 2
(i.e., wick) is material of high heat conductance, such as silver,
copper, and aluminum, etc. The metal net structure 2 is made of
above-mentioned materials by the connection technique (i.e.,
diffusion bonding) of micro electric mechanic system (MEMS). The
entire metal net structure 2 may be designed according to the
requirements of different products. Several metal-net structures 2
of different meshes and thread radiuses may be connected together
to form a specific flow field, in which has a characteristic of
excellent partial heat-transfer to transfer the heat of the
heat-absorbing part of system into the entire metal net structure
2. This metal net structure 2 also has good property of containing
water. After the heat is transferred from outside into the metal
net structure 2 that is filled with fluid, since this design will
result redundant heat (i.e., higher temperature) that is partially
accumulated inside the meshes of the metal net structure 2, so it
will make the liquid inside the metal net structure 2 generate
partial gasification. The gasified fluid will flow outwardly from
the metal net structure 2, while the fluid in the metal net
structure 2 after being partially gasified will absorb the
condensed liquid fluid in the heat-dissipating zone 12 from outside
into the metal net structure 2 by the principle of capillary action
and under the condition of no additional acting-force.
[0021] The flexible metal film 1 of above description is a metal
film made of basic material that has high heat-conductance, such as
silver, copper, and aluminum, etc. The diameters of the micro flow
path inside the heat dissipation zone 12 are between hundreds
micro-meters to several micro-meters in order to facilitate both
the heat-dissipation and the capillary action.
[0022] In summarizing above description, the MICRO-LOOP HEAT PIPE
of the invention has applied the micro electric mechanic system
(MEMS) to design and manufacture out the key element--"wick"--that
is capable of mass production. The invention applies the
flexibility of the elements or devices needed heat-dissipation for
making flexible contact. The structure is adapted for all different
products and may be optimally designed and matched with practical
needs.
* * * * *