U.S. patent application number 12/873253 was filed with the patent office on 2012-03-01 for heat pipe with composite wick structure.
This patent application is currently assigned to Kunshan Jue-Chung Electronics Co.. Invention is credited to Yu- Po Huang, Tung-Jung Kuo.
Application Number | 20120048517 12/873253 |
Document ID | / |
Family ID | 45695582 |
Filed Date | 2012-03-01 |
United States Patent
Application |
20120048517 |
Kind Code |
A1 |
Huang; Yu- Po ; et
al. |
March 1, 2012 |
HEAT PIPE WITH COMPOSITE WICK STRUCTURE
Abstract
The heat pipe of the invention includes a tube in which an
evaporating portion and a condensing portion are defined; a grooved
wick longitudinally and entirely disposed on an inner wall of the
tube and communicating the evaporating portion with the condensing
portion; a porous wick only disposed on the inner wall of the
evaporating portion and covering the grooved wick in the
evaporating portion; and a fiber wick in a shape of a strip, whose
one end connects the porous wick and whose the other end
longitudinally extends to the condensing portion.
Inventors: |
Huang; Yu- Po; (Kunshan
City, CN) ; Kuo; Tung-Jung; (Kunshan City,
CN) |
Assignee: |
Kunshan Jue-Chung Electronics
Co.,
|
Family ID: |
45695582 |
Appl. No.: |
12/873253 |
Filed: |
August 31, 2010 |
Current U.S.
Class: |
165/104.26 |
Current CPC
Class: |
F28D 15/0233 20130101;
F28D 15/046 20130101 |
Class at
Publication: |
165/104.26 |
International
Class: |
F28D 15/04 20060101
F28D015/04 |
Claims
1. A heat pipe with composite wick structure, comprising: a tube in
which an evaporating portion and a condensing portion are defined;
a grooved wick substantially longitudinally and entirely disposed
on an inner wall of the tube and communicating the evaporating
portion with the condensing portion; a porous wick only disposed on
the inner wall of the evaporating portion and covering the grooved
wick in the evaporating portion; and a fiber wick in a shape of a
strip, wherein one end of the fiber wick connects the porous wick
and the other end thereof longitudinally extends to the condensing
portion.
2. The heat pipe with composite wick structure of claim 1, wherein
the evaporating portion is located at one end of the tube.
3. The heat pipe with composite wick structure of claim 2, wherein
the condensing portion is located at the other end of the tube.
4. The heat pipe with composite wick structure of claim 1, wherein
the porous wick is sintered powder.
5. The heat pipe with composite wick structure of claim 4, wherein
one end of the fiber wick is sintered together with the porous
wick.
6. The heat pipe with composite wick structure of claim 1, wherein
one end of the fiber wick is sintered together with the porous
wick.
7. The heat pipe with composite wick structure of claim 1, wherein
the fiber wick is woven fiber.
8. The heat pipe with composite wick structure of claim 1, wherein
the fiber wick is woven metallic wires.
9. The heat pipe with composite wick structure of claim 1, wherein
the other end of the fiber wick is placed in the condensing portion
without fastening.
10. The heat pipe with composite wick structure of claim 1, wherein
the tube is flat in shape and the fiber wick in the condensing
portion is gripped by the tube.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The invention generally relates to heat transfer elements,
particularly to heat pipes.
[0003] 2. Related Art
[0004] A heat pipe is a heat transfer element which employing phase
transition to efficiently transfer heat between two solid
interfaces. Usually, an evaporating portion and a condensing
portion are separately defined at two ends of a heat pipe. At the
evaporating portion, a work fluid within the heat pipe turns into a
vapor by absorbing the heat. The vapor condenses back into a liquid
at the condensing portion, releasing the latent heat by a heat
sink. The liquid then returns to the evaporating portion through
either capillary action or gravity action where it evaporates once
more and repeats the cycle.
[0005] In practice, heat pipes are not always arranged in a
direction that the evaporating portion is downward. Sometimes a
heat pipe may be arranged reversely or obliquely. This tends to
make the work fluid which is in liquid phase and is flowing back
contained by gravity. In a traditional heat pipe, the wick
structure is placed on an inner wall of the pipe. Thus only a part
of wick structure can provide a capillary force to push the work
fluid when the heat pipe is slant. The efficiency of flowing back
of the work fluid is not good enough.
SUMMARY OF THE INVENTION
[0006] An object of the invention is to improve the efficiency of
flowing back of work fluid regardless of the direction of heat
pipe.
[0007] To accomplish the above object, the heat pipe of the
invention includes a tube in which an evaporating portion and a
condensing portion are defined; a grooved wick longitudinally and
entirely disposed on an inner wall of the tube and communicating
the evaporating portion with the condensing portion; a porous wick
only disposed on the inner wall of the evaporating portion and
covering the grooved wick in the evaporating portion; and a fiber
wick in a shape of a strip, whose one end connects the porous wick
and whose the other end longitudinally extends to the condensing
portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a longitudinal sectional view of the first
embodiment of the invention;
[0009] FIG. 2 is a cross-sectional view along line 2-2 in FIG.
1;
[0010] FIG. 3 is a cross-sectional view along line 3-3 in FIG.
1;
[0011] FIG. 4 is a partially sectional view of the first embodiment
of the invention;
[0012] FIG. 5 shows a typical application of the first embodiment
of the invention;
[0013] FIG. 6 is a cross-sectional view of the evaporating portion
of the second embodiment of the invention; and
[0014] FIG. 7 is a cross-sectional view of the condensing portion
of the second embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Please refer to FIGS. 1 and 4. The heat pipe of the
invention includes a tube 10, a grooved wick 11, a porous wick 12
and a fiber wick 13.
[0016] An evaporating portion 100 and a condensing portion 101 are
defined in the tube 10. In the shown embodiment, the evaporating
portion 100 and the condensing portion 101 are separately located
at two ends of the tube 10. Of course, there may be a plurality of
evaporating portions 100 or condensing portions 101. The grooved
wick 11 is longitudinally and entirely disposed on an inner wall of
the tube 10 and communicates the evaporating portion 100 and the
condensing portion 101. A work fluid (not shown) contained in the
tube 10 may flow back from the condensing portion 101 to the
evaporating portion 100 through the grooved wick 11.
[0017] The porous wick 12 is made of sintered powder. The porous
wick 12 is only disposed on the inner wall of the evaporating
portion 100 and covers the grooved wick 11 in the evaporating
portion 100.
[0018] Please refer to FIGS. 2 and 3. The fiber wick 13 is a strip
of woven fiber or metallic wires. One end 130 of the strip of fiber
wick 13 connects to the porous wick 12 as shown in FIG. 3. For
example, the end 130 is sintered together with the porous wick 12
when the porous wick 12 is being sintered. The other end 131 of the
fiber wick 13 longitudinally extends to the condensing portion 101
as shown in FIG. 2. In this embodiment, the end 131 of the fiber
wick 13 is just placed at the condensing portion 101 without any
fastening. Preferably, a cross-sectional area of the fiber wick 13
is about one eighth of that of the tube 10.
[0019] As shown in FIG. 5, the evaporating portion 100 is touched
by a heat source 2 and the condensing portion 101 is connected with
fins 3. When the heat source 2 is generating heat, the work fluid
in the porous wick 12 starts evaporating. The evaporated work fluid
will move to the condensing portion 101 because the porous wick 12
is only located in the evaporating portion 100. The evaporated work
fluid will further condense by releasing heat to the fins 3. Then
the condensed work fluid flows back the evaporating portion 100
through the grooved wick 11. If the heat pipe 1 is arranged in a
direction disadvantageous to the flowing back of the work fluid,
the distal end 131 of the fiber wick 13 will naturally pend because
of gravity. The pendent fiber wick 13 will reach and absorb the
condensed work fluid to transfer it back to the porous wick 12 in
the evaporating portion 100. The efficiency of heat transfer of the
heat pipe 1 can be increased.
[0020] Additionally, the tube 10 of the heat pipe 1 also can be
flat so as to make the fiber wick 13 in the condensing portion 101
gripped by the tube 10 as shown in FIG. 7. But the fiber wick 13 in
the evaporating portion 100 is pressed by the porous wick 12 and
not touched by the tube 10.
[0021] While the forgoing is directed to preferred embodiments of
the present invention, other and further embodiments of the
invention may be devised without departing from the basic scope
thereof. As such, the appropriate scope of the invention is to be
determined according to the claims.
* * * * *