U.S. patent application number 11/309745 was filed with the patent office on 2008-03-27 for pulsating heat pipe with flexible artery mesh.
This patent application is currently assigned to FOXCONN TECHNOLOGY CO., LTD.. Invention is credited to CHANG-SHEN CHANG, JUEI-KHAI LIU, HSIEN-SHENG PEI, CHAO-HAO WANG.
Application Number | 20080073066 11/309745 |
Document ID | / |
Family ID | 39223679 |
Filed Date | 2008-03-27 |
United States Patent
Application |
20080073066 |
Kind Code |
A1 |
CHANG; CHANG-SHEN ; et
al. |
March 27, 2008 |
PULSATING HEAT PIPE WITH FLEXIBLE ARTERY MESH
Abstract
A pulsating heat pipe (10) includes an elongate capillary tube
(11), a working fluid (15) disposed within the elongate tube and an
artery mesh (13) disposed in the elongate tube. The capillary tube
includes a plurality of heat receiving portions (112) located on a
first predetermined part of the elongate tube, and a plurality of
heat radiating portions (114) located on a second predetermined
part of the elongate tube. The heat receiving and heat radiating
portions are alternatively disposed on the elongate tube. The
working fluid is propelled to flow between the heat receiving and
heat radiating portions via a first channel (132) defined in the
artery mesh and a second channel (133) defined between the artery
mesh and the elongate tube.
Inventors: |
CHANG; CHANG-SHEN;
(Tu-Cheng, TW) ; LIU; JUEI-KHAI; (Tu-Cheng,
TW) ; WANG; CHAO-HAO; (Tu-Cheng, TW) ; PEI;
HSIEN-SHENG; (Tu-Cheng, TW) |
Correspondence
Address: |
PCE INDUSTRY, INC.;ATT. CHENG-JU CHIANG JEFFREY T. KNAPP
458 E. LAMBERT ROAD
FULLERTON
CA
92835
US
|
Assignee: |
FOXCONN TECHNOLOGY CO.,
LTD.
Taipei Hsien
TW
|
Family ID: |
39223679 |
Appl. No.: |
11/309745 |
Filed: |
September 21, 2006 |
Current U.S.
Class: |
165/104.26 ;
165/104.21 |
Current CPC
Class: |
F28D 15/046 20130101;
F28D 15/0266 20130101; F28D 15/0233 20130101 |
Class at
Publication: |
165/104.26 ;
165/104.21 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
Claims
1. A pulsating heat pipe comprising: an elongate capillary tube
comprising a plurality of heat receiving portions located on a
first predetermined part of the elongate tube, and a plurality of
heat radiating portions located on a second predetermined part of
the elongate tube, the heat receiving and heat radiating portions
being alternatively disposed on the elongate tube; a working fluid
disposed within the elongate tube; and an artery mesh disposed in
the elongate tube, the working fluid being propelled to flow
between the heat receiving and heat radiating portions via a first
channel defined in the artery mesh and a second channel defined
between the artery mesh and the elongate tube.
2. The pulsating heat pipe of claim 1, wherein the artery mesh has
an adjacent portion contacting with an inner wall of the capillary
tube, and a distant portion spaced at a distance from the inner
wall of the capillary tube.
3. The pulsating heat pipe of claim 1, wherein the elongate
capillary tube is hand-shaped in profile and has two terminals
hermetically connected with each other to form a close looped flow
passage of the working fluid.
4. The pulsating heat pipe of claim 1, wherein the artery mesh is
an elongate hollow tube formed by weaving a plurality of metal
wires.
5. The pulsating heat pipe of claim 4, wherein the metal wires are
selected from a group consisting of copper wires and stainless
steel wires.
6. The pulsating heat pipe of claim 1, wherein the artery mesh
comprises a plurality of spaced segments disposed in the entire
elongate capillary tube.
7. The pulsating heat pipe of claim 1, wherein the elongate
capillary tube is made of deformable metallic materials.
8. The pulsating heat pipe of claim 1, wherein the working fluid
comprises a plurality of liquid segments and vapor bubbles
alternately distributed along the elongate capillary tube.
9. The pulsating heat pipe of claim 1 further comprising a filling
tube for filling and supplying the working fluid into the elongate
capillary tube.
10. The pulsating heat pipe of claim 1 further comprising at least
one pressure sensitive check valve disposed in a circulation
passage of the working fluid for limiting flowing direction of the
working fluid.
11. A pulsating heat pipe comprising: an elongate tube; working
fluid received in the elongate tube and comprising liquid segments
and vapor bubbles distributed between the liquid segments; and an
artery mesh received in the elongate tube, wherein a first channel
for movement of the working fluid in the pulsating heat pipe is
defined between an outer wall of the artery mesh and the an inner
wall of the elongate tube, and a second channel for movement of the
working fluid in the pulsating heat pipe is defined in the artery
mesh.
12. The pulsating heat pipe of claim 11, wherein the artery mesh
has an adjacent side abutting against the inner wall of the
elongate tube.
13. The pulsating heat pipe of claim 12, wherein the elongate tube
is made of one of aluminum and copper.
14. The pulsating heat pipe of claim 12, wherein the artery mesh is
formed by weaving metal wires.
15. The pulsating heat pipe of claim 14, wherein the artery mesh is
formed by weaving stainless steel wires.
16. The pulsating heat pipe of claim 14, wherein the artery mesh is
formed by weaving copper wires.
17. The pulsating heat pipe of claim 14, wherein the artery mesh is
formed by weaving a plurality of fiber together.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to a pulsating heat
pipe for transfer or dissipation of heat from heat-generating
components, and more particularly to a pulsating heat pipe with
flexible artery mesh disposed therein for improving heat
dissipation for the heat-generating components.
DESCRIPTION OF RELATED ART
[0002] Pulsing heat pipes have excellent heat transfer performance
due to their low thermal resistance, and are therefore an effective
means for transfer or dissipation of heat from heat-generating
components such as central processing units (CPUs) of
computers.
[0003] A pulsating heat pipe is usually an elongate capillary tube
containing therein a working fluid, which is employed to carry,
under phase transitions between liquid state and vapor state,
thermal energy from one section of the pulsating heat pipe
(typically referring to as the "heating section") to another
section thereof (typically referring to as the "cooling section").
In the pulsating heat pipe, there is no wick structure inside the
capillary tube. The working fluid is drawn back to the heating
section after it is condensed at the cooling section under a
capillary force generated by the capillary tube and a difference of
vapor pressure between the two sections of the pulsating heat pipe.
This decreases the thermal resistance thereof and therefore
prevents the pulsating heat pipe from dry-out at a higher
temperature.
[0004] However, there is no additional wick structure disposed in
the capillary tube. The pulsating heat pipe is operated under the
capillary force generated by the capillary tube. The capillary
force is weak in conquering gravity of the working fluid.
Therefore, during start up of the pulsating heat pipe, the working
fluid at the heating section needs to be heated to vaporize an
enough inflating force to conquer gravity of the working fluid so
that the vaporized working fluid thereat is driven towards the
cooling section. Thus, the pulsating heat pipe has troubles to be
operated in lower temperature.
[0005] Therefore, it is desirable to provide a pulsating heat pipe
which has better gravity conquest capability and easily to be
operated under a lower temperature.
SUMMARY OF THE INVENTION
[0006] The present invention relates to a pulsating heat pipe for
removing heat from heat-generating components. The pulsating heat
pipe includes an elongate capillary tube, a working fluid disposed
within the elongate tube and an artery mesh disposed in the
elongate tube. The capillary tube includes a plurality of heat
receiving portions located on a first predetermined part of the
elongate tube, and a plurality of heat radiating portions located
on a second predetermined part of the elongate tube. The heat
receiving and heat radiating portions are alternatively disposed on
the elongate tube. The working fluid is propelled to flow between
the heat receiving and heat radiating portions via a first channel
defined in the artery mesh and a second channel defined between the
artery mesh and the elongate tube.
[0007] 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
[0008] Many aspects of the present invention can be better
understood with reference to the following 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 invention. Moreover, in the drawings, like reference
numerals designate corresponding parts throughout the several
views:
[0009] FIG. 1 is a pulsating heat pipe in accordance with a
preferred embodiment of the present invention;
[0010] FIG. 2 is an enlarged view of a circled portion II of the
pulsating heat pipe of FIG. 1 ;
[0011] FIG. 3 is an enlarged transverse cross-sectional view of the
pulsating heat pipe of FIG. 1, taken along line III-III
thereof;
[0012] FIG. 4 is a front view of a mesh of the pulsating heat pipe
of FIG. 1;
[0013] FIG. 5 a transverse cross-sectional view of the mesh of FIG.
4, taken along line V-V thereof; and
[0014] FIG. 6 is a pulsating heat pipe in accordance with another
embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] FIG. 1 illustrates a pulsating heat pipe 10 in accordance
with a preferred embodiment of the present invention. The pulsating
heat pipe 10 includes a serpentine, elongate capillary tube 11, a
flexible interwoven artery mesh 13 disposed within the elongate
capillary tube 11, and a predetermined quantity of condensable
bi-phase working fluid 15 (FIG. 2) filled in the elongate capillary
tube 11 and the artery mesh 13.
[0016] The elongate capillary tube 11 is made of deformable
metallic materials, such as copper or aluminum, so it can be bent
into a required shape by a suitable bending machine (not shown).
Alternatively, the elongate capillary tube 11 may be made of other
deformable materials such as polymer or macro-molecular material.
The elongate capillary tube 11 is bent into a hand-like shape,
having a plurality of heat receiving and heat radiating portions
112, 114 formed on predetermined parts thereof, and a plurality of
adiabatic portions 116 formed between the heat receiving and heat
radiating portions 112, 114. The heat receiving portions 112 are
alternately arranged with the heat radiating portions 114. It is
noted that the heat receiving portions 112 are disposed in a
heating region H and the heat radiating portions 114 are disposed
in a cooling region C. The heating region H is located at
fingertips of the hand, while the cooling region C is located near
a wrist of the hand. Terminal ends (not labeled) of the metallic
elongate capillary tube 11 are hermetically connected with each
other to form a close looped flow passage of the working fluid 15.
Alternatively, shown in FIG. 6, the terminal ends of the elongate
capillary tube 11 may be heretically sealed and separated from each
other to form an un-looped flow passage of the working fluid 15. In
addition, a filling tube 17 is formed at the cooling region C of
the elongate capillary tube 11 for filling and supplying the
working fluid 15 into the elongate capillary tube 11.
[0017] Referring to FIGS. 2 to 5, the artery mesh 13 is an elongate
hollow tube, which is attached to an inner wall of the elongate
capillary tube 11 and extends along the entire length of the
capillary tube 11. Alternatively, the elongate artery mesh 13 may
be divided into a plurality of spaced segments (shown in FIG. 6),
which are equidistantly disposed in the elongate capillary tube 11.
Further alternatively, the spaced segments may also be not
equidistant from each other in some parts of the elongate capillary
tube 11. The artery mesh 13 is formed by weaving a plurality of
metal wires 131 (FIG. 4), such as copper, or stainless steel wires
together. Alternatively, the artery mesh 13 can be formed by
weaving a plurality of non-metal threads such as fiber together. A
first channel 132 is defined in an inner space of the artery mesh
13, whilst a second channel 133 is defined between an outer wall of
the artery mesh 13 and the inner wall of the elongate capillary
tube 11. Both first and second channels 132, 133 are for passages
of vaporized working fluid 15. A plurality of pores (not shown) is
formed in a peripheral wall of the artery mesh 13, which provides a
first strong circulation propelling force (capillary action) to the
working fluid 15 and communicates the first channel 132 with the
second channel 133. The artery mesh 13 has a ring-like transverse
cross section, a diameter of which is smaller than a diameter of
the elongate capillary tube 11. The artery mesh 13 has a linear
contact with the inner wall of the elongate capillary tube 11
thereby defining an adjacent portion 134 contacting with the inner
wall of the elongate capillary tube 11 and a distal portion 135
spaced a distance from the inner wall of the elongate capillary
tube 11 along a radial direction of the pulsating heat pipe 10. In
the present pulsating heat pipe 10, the artery mesh 13 may be
loosely inserted into the elongate capillary tube 11 with some
portions thereof separating from the inner wall of the elongate
capillary tube 11.
[0018] Particularly referring to FIG. 1, the working fluid 15 is
filled in the artery mesh 13 and the elongate capillary tube 11.
The working fluid 15 is usually selected from a liquid such as
water, methanol, or alcohol, which has a low boiling point and is
compatible with the artery mesh 13. Thus, the working fluid 15 can
easily evaporate to vapor when it receives heat at the heating
region H of the pulsating heat pipe 10. The elongate capillary tube
11 of the pulsating heat pipe 10 is evacuated and hermetically
sealed after the working fluid 15 is injected into the elongate
capillary tube 11 and fills the capillary tube 11 and the artery
mesh 13. Before operation, capillary effect causes the working
fluid 15 to form as piece-wise liquid segments 151 distributed
along the elongate capillary tube 11, and vapor bubbles 152 existed
between the liquid segments 151. During operation, the heating
region H is heated to vaporize the working fluid 15 which generates
a vapor pressure thereat, whilst the cooling region C is cooled to
condense the vaporized working fluid 15 which generates a negative
vapor pressure (attracting force) thereat. Mutual actions between
the vapor pressure and the attracting force cooperatively cause the
liquid segments 151 and the vapor bubbles 152 to pulsate in and
finally generate a second strong circulation propelling force to
propel the working fluid 15 to circulate in the capillary tube
11.
[0019] In addition, one or a plurality of pressure sensitive
small-sized check valves 19 (shown in FIG. 6) may be disposed in
the circulation passage of the working fluid 15 for limiting
flowing direction of the working fluid 15. Mutual distances between
the check valves 19 are balanced. It is noted that as the number of
the check valves 19 increases, the circulation of the working fluid
15 becomes strong and fast.
[0020] In operation, the heat receiving portions 112 generate the
vapor pressure due to the vaporization of the working fluid 15
thereat and the heat radiating portions 114 generate the attracting
force due to the condensation of the vapor. The artery mesh 13, and
the vapor pressure and attracting force generate the respective
first and second strong propelling actions toward a predetermined
circulation direction for the working fluid 15 and its vapor. These
mutual actions cause the working fluid 15 and its vapor to continue
circulation at a high speed in the looped elongate capillary tube
11. The circulating working fluid 15 is vaporized by an amount of
heat supplied at the heat receiving portions 112 to form the vapor.
The amount of heat is absorbed as a latent heat in the
vaporization, and the vapor streams in the first channel 132 of the
artery mesh 13 and the second channel 133 between the artery mesh
13 and the looped elongate capillary tube 11. When the stream of
vapor reaches the heat radiating portions 114, the stream of vapor
is cooled and liquefied to the working fluid 15. During the
liquefication, the vapor supplies the amount of heat for the heat
radiating portions 114 as the latent heat in condensation to
radiate heat externally. In this way, the working fluid 15
circulates within the looped elongate capillary tube 11 and the
artery mesh 13 and repeats the vaporization and condensation, i.e.,
the heat reception and the heat radiation.
[0021] In the pulsating heat pipe 10, the first propelling action,
i.e., the capillary action generated by the artery mesh 13 helps to
conquer the gravity of and propel the working fluid 15 to circulate
in the elongate capillary tube 11, so that the required start up
pressure generated by heating the heating region H of the pulsating
heat pipe 10 is decreased. The required start up temperature of the
pulsating heat pipe 10 is accordingly decreased, which results in
the pulsating heat pipe 10 being easy to be operated under a lower
temperature. In addition, the artery mesh 13 helps to prevent the
working fluid 15 from accumulating in some portions of the elongate
capillary tube 11, which further decreases the required start up
pressure of the pulsating heat pipe 10. Therefore, the pulsating
heat pipe 10 is capable of being used for dissipating heat
generated by heat sensitive electronic components.
[0022] 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.
* * * * *