U.S. patent application number 12/755557 was filed with the patent office on 2010-12-16 for heat exchanger having micro-channels.
This patent application is currently assigned to AGENCY FOR DEFENSE DEVELOPMENT. Invention is credited to Sang Wook Jin, Jin Shik Lim, Seong Ki Min, Kwang Yoon Oh, Geun Hong Park, Young June Yoo.
Application Number | 20100314088 12/755557 |
Document ID | / |
Family ID | 41810250 |
Filed Date | 2010-12-16 |
United States Patent
Application |
20100314088 |
Kind Code |
A1 |
Yoo; Young June ; et
al. |
December 16, 2010 |
HEAT EXCHANGER HAVING MICRO-CHANNELS
Abstract
Disclosed is a heat exchanger configured by laminating layers
having micro-channels by adapting a micromachining, wherein the
micro-channels having uniform length and cross section are
constructed within a heat exchanger body in a curved outer shape,
thereby minimizing deviation for each channel and improving heat
transfer efficiency.
Inventors: |
Yoo; Young June; (Daejeon,
KR) ; Lim; Jin Shik; (Daejeon, KR) ; Min;
Seong Ki; (Daejeon, KR) ; Park; Geun Hong;
(Daejeon, KR) ; Jin; Sang Wook; (Yuseong-Gu,
KR) ; Oh; Kwang Yoon; (Gyeongsangnam-Do, KR) |
Correspondence
Address: |
Vierra Magen Marcus & DeNiro LLP
575 Market Street, Suite 2500
San Francisco
CA
94105
US
|
Assignee: |
AGENCY FOR DEFENSE
DEVELOPMENT
Daejeon
KR
|
Family ID: |
41810250 |
Appl. No.: |
12/755557 |
Filed: |
April 7, 2010 |
Current U.S.
Class: |
165/170 |
Current CPC
Class: |
F28F 2260/02 20130101;
F28F 3/048 20130101; F28F 13/06 20130101; F28D 9/0062 20130101 |
Class at
Publication: |
165/170 |
International
Class: |
F28F 3/00 20060101
F28F003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 11, 2009 |
KR |
10-2009-0051898 |
Claims
1. A heat exchanger having micro-channels comprising: a heat
exchanger body having a plurality of layers laminated, each layer
having a plurality of micro-channels; a high temperature fluid
inlet body and a low temperature fluid outlet body detachably
connected to one end portion of the heat exchanger body; and a low
temperature fluid inlet body and a high temperature fluid outlet
body detachable connected to another end portion of the heat
exchanger body, wherein both side surfaces defining a width of the
heat exchanger body have a first curvature profile and a second
curvature profile in parallel to the first curvature profile.
2. The heat exchanger of claim 1, wherein the heat exchanger body
comprises: a hot side layer having a plurality of first
micro-channels in parallel to one another, high temperature fluid
flowing within the plurality of first micro-channels; and a cold
side layer having a plurality of second micro-channels in parallel
to one another, low temperature fluid flowing within the plurality
of second micro-channels.
3. The heat exchanger of claim 2, wherein the first and second
micro-channels respectively comprise n micro-channels, n.gtoreq.2,
wherein i.sup.th (i=natural number) channel of the channels may
include an inlet portion having a length X.sub.i, a curved portion
having a length W.sub.i and an outlet portion having a length
Y.sub.i, wherein X.sub.i, Y.sub.i and W.sub.i are constructed to
meet the following equation. X.sub.i+Y.sub.i+W.sub.i=Constant
4. The heat exchanger of claim 3, wherein a width between one
curved portion and another curved portion adjacent thereto, among
the curved portions, is constantly maintained in a lengthwise
direction.
5. The heat exchanger of claim 4, wherein the curved portion is
configured in a wavy form.
Description
CROSS-REFERENCE TO A RELATED APPLICATION
[0001] This application claims the benefit of and right of priority
to Korean Application No. 10-2009-0051898, filed on Jun. 11, 2009,
the contents of which is incorporated by reference herein in its
entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a heat exchanger having
micro-channels formed by micromachining.
BACKGROUND OF THE INVENTION
[0003] Heat exchangers employed for special use are used in high
temperature and high pressure environments, unlike typical heat
exchangers, or required to be compact and durable in order to meet
constraint conditions, such as weight, space and the like.
[0004] Gas-to-gas heat exchange needs a greater heat transfer area
for the same heat exchange due to a low overall heat transfer
coefficient, which causes difficulty in adapting the same to cases
having constraint conditions of weight and space.
[0005] A printed circuit heat exchanger (PCHE), as a type of
micro-channel heat exchanger, is made by alternately bonding
different plates, having channels formed through etching, with
interposing a separating plate therebetween. The PCHE has several
advantages of forming millimeter-sized channels and having a large
heat transfer area, compared to a usage space, by providing a large
heat transfer area with allowing free flow of liquid as well as
gas. Also, the PCHE has advantage of configuring a heat exchanger
profitable for high temperature and high pressure usage
environments. Improvement of a micro electro mechanical system
(MEMS) field allows the PCHE to be fabricated in various forms by
utilizing a variety of micromachining.
[0006] The PCHE having a compact size and high performance is
applied to various fields, namely, energy technologies relating to
energy-associated industries and the like as well information
technologies relating to computers, semiconductors and the like. In
addition, the PCHE has a great ripple effect not only on
petrochemical plants needing micro-channel heat exchangers but also
on other industries, such as fuel cell reactors, waste heat
recovery facilities, refrigeration and air-conditioning industries
of CO2 heat pumps, water heaters and the like.
[0007] For a typical heat exchanger, when heat transfer is
increased, pressure drop is simultaneously increased. However, by a
design of the form of a micro-channel heat exchanger, the large
amount of heat transfer can be generated with maintaining a small
amount of pressure drop.
[0008] However, in case of a rectangular heat exchanger designed by
the related art, since the shape and outline of flow channels are
simple, it is relatively easy to design the shape of the flow
channels, but usually difficult to meet a spatial condition within
a device for mounting the heat exchanger therein. In particular, if
an overall outline has a curvature, the design of flow channels
having the same flow length becomes more difficult.
SUMMARY OF THE INVENTION
[0009] Therefore, in order to obviate such problems of the related
art, an object of the present invention is to provide a heat
exchanger capable of implementing high performance by designing
micro-channels having the same flow length when an outer appearance
thereof has a curvature.
[0010] To achieve this and other advantages and in accordance with
the purpose of the present invention, as embodied and broadly
described herein, there is provided a heat exchanger having
micro-channels including a heat exchanger body having a plurality
of layers laminated, each layer having a plurality of
micro-channels, a high temperature fluid inlet body and a low
temperature fluid outlet body detachably connected to one end
portion of the heat exchanger body, and a low temperature fluid
inlet body and a high temperature fluid outlet body detachable
connected to another end portion of the heat exchanger body,
wherein both side surfaces defining a width of the heat exchanger
body have a first curvature profile and a second curvature profile
in parallel to the first curvature profile.
[0011] As one example of the present invention, the heat exchanger
body may include a hot side layer having a plurality of first
micro-channels in parallel to one another, high temperature fluid
flowing within the plurality of first micro-channels, and a cold
side layer having a plurality of second micro-channels in parallel
to one another, low temperature fluid flowing within the plurality
of second micro-channels.
[0012] As one example of the present invention, the micro-channels
may comprise n micro-channels (n.gtoreq.2), and ith (i=natural
number) channel of the channels may include an inlet portion having
a length Xi, a curved portion having a length Wi and an outlet
portion having a length Yi, wherein Xi, Yi and Wi may be
constructed to meet the following equation.
Xi+Yi+Wi=Constant
[0013] As one example of the present invention, a width between one
curved portion and another curved portion adjacent thereto, among
the curved portions, may be constantly maintained in a lengthwise
direction.
[0014] As one example of the present invention, the curved portion
may be configured in a wavy form.
[0015] According to the heat exchanger relating to the present
invention, micro-channels can be formed in a heat exchanger body
having a curved outer shape, thereby remarkably improving heat
exchange efficiency as compared to a heat exchanger according to
the related art.
[0016] According to one example of the present invention, wavy
micro-channels may be employed in the heat exchanger body having
the curved outer shape such that a total length and a cross section
of each micro-channel are the same, thereby minimizing deviation
for each channel.
[0017] Also, the heat exchanger having the curved outer shape and
excellent heat transfer performance can be easily installed even at
a place where it is difficult to install a linear type heat
exchanger of the related art, thereby improving the
installation.
[0018] The foregoing and other objects, features, aspects and
advantages of the present invention will become more apparent from
the following detailed description of the present invention when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and together with the description serve to explain
the principles of the invention.
[0020] FIG. 1 is a perspective view showing one example of a
micro-channel heat exchanger in accordance with the present
invention.
[0021] FIG. 2 is a disassembled perspective view showing a low
temperature fluid inlet body and a high temperature fluid outlet
body being disassembled from the heat exchanger body of FIG. 1;
[0022] FIG. 3 is a disassembled perspective view showing a unit
module configuring the heat exchanger body.
[0023] FIG. 4 is a planar view showing a schematic shape of each
micro-channel.
[0024] FIG. 5 is a planar view of micro-channels having gently
curved flow channels, as one example according to the present
invention.
[0025] FIG. 6 is a diagram showing a process of constructing a wavy
flow channel, as one example according to the present
invention.
[0026] FIG. 7 is a planar view of micro-channels according to the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Description will now be given in detail of the present
invention, with reference to the accompanying drawings.
[0028] FIG. 1 is a perspective view showing one example of a
micro-channel heat exchanger in accordance with the present
invention. As shown in FIG. 1, a heat exchanger may include a heat
exchanger body 10 having a curved shape, a high temperature fluid
inlet body 20 and a low temperature fluid outlet body 50 detachably
connected to one end portion of the heat exchanger body 10, and a
low temperature fluid inlet body 40 and a high temperature fluid
outlet body 30 attached onto another end portion of the heat
exchanger body 10.
[0029] One side surface 60A of both side surfaces 60A and 60B (see
FIG. 2), which define a width of the heat exchanger body 10 may
have a first curvature profile, and another side surface 60B may
have a second curvature profile in parallel to the first curvature
profile. The first curvature profile and the second curvature
profile may possibly be arcuately formed. Alternatively, they can
be formed in a shape of an oval or a parabola or a combination
thereof.
[0030] A high temperature fluid inlet pipe 21 may be disposed at an
end of the high temperature fluid inlet body 20. High temperature
fluid introduced into the singular high temperature fluid inlet
pipe 21 is diffused into each micro-channel by the high temperature
fluid inlet body 20 and flows within the heat exchanger body 10 so
as to exchange heat with low temperature fluid. Such heat-exchanged
fluid are all combined at the high temperature fluid outlet body 30
so as to be discharged via a high temperature fluid outlet pipe 31.
Similar to this, a low temperature fluid inlet pipe 41 may be
disposed at an end of the low temperature fluid inlet body 40. Low
temperature fluid introduced into the singular low temperature
fluid inlet pipe 41 is diffused into micro-channels, which are
different from the high temperature side micro channels, by the low
temperature fluid inlet body 40, and flows within the
heat-exchanger body 10 so as to exchange heat with high temperature
fluid. Such heat-exchanged fluid are all combined at the low
temperature fluid outlet body 50 so as to be discharged via a low
temperature fluid outlet pipe 51.
[0031] FIG. 2 is a disassembled perspective view showing a low
temperature inlet body and a high temperature outlet body being
disassembled from the heat exchanger body of FIG. 1, and FIG. 3 is
a disassembled perspective view showing a unit module configuring
the heat exchanger body.
[0032] Referring to FIGS. 2 and 3, the heat exchanger body 10 may
have a structure in which a plurality of layers each having
micro-channels are laminated.
[0033] A unit module 10' may include a hot side layer 12, a cold
side layer 13 and a separating plate 11. The hot side layer 12 may
be provided with a plurality of first micro-channels in which high
temperature fluid flows, and the cold side layer 13 may be provided
with a plurality of second micro-channels 13a in which low
temperature fluid flows.
[0034] When viewed in a planar view, the hot side layer 12 and the
cold side layer 13 forming the unit module 10' may commonly include
end portion surfaces 61A, 61B, 61C and 61D in addition to the side
surfaces 60A and 60B as aforesaid. The end portion surfaces 61A,
61B, 61C and 61D may be formed in a symmetrical shape with respect
to a central arc so as to allow attachment of the high temperature
fluid inlet body 20, the low temperature fluid inlet body 50, the
high temperature fluid outlet body 30 and the low temperature fluid
outlet body 40 all having the same size.
[0035] The hot side layer 12 and the cold side layer 13 may be
bonded to each other by interposing the separating plate 11
therebetween, thereby sealing the first micro-channel 12a and the
second micro-channel 13a, respectively. Thus, high temperature
fluid flowing within the first micro-channels 12a can exchange heat
with low temperature fluid of the second micro-channels 13a via the
separating plate 11.
[0036] The micro-channel exchanger 1 employs a method for uniformly
fixing an amount of pressure drop for distributing uniform fluid
into each channel. That is, a flow channel length of the heat
exchanger, which may be an important factor for determining
efficiency of the heat exchanger is required to be equally set for
all flow channels, in order to prevent decrease of the efficiency
due to deviation of fluid introduced into each channel. If each
micro-channel has a different length, fluid is excessively supplied
into a short micro-channel, which may fatally affect the overall
efficiency of the heat exchanger. Also, for fixing a constant
amount of pressure drop, the flow channel within each micro-channel
is fabricated to have the same flow length and shape. In the
meantime, in case of employing wavy micro-channels other than
linear micro-channels, heat transfer and the pressure drop can be
increased. However, it has been known that heat transfer as
compared to pressure drop is the most effective at an angle of
approximately 30.degree. based upon a proceeding direction of the
micro-channel.
[0037] Therefore, the embodiment illustrates that, in order to
obtain high efficiency of a heat exchanger having a curved outer
shape, each micro-channel within the heat exchanger body 10 in the
curved outer shape can be implemented in a wavy shape so as to
constantly maintain the total length of each micro-channel.
[0038] FIG. 4 is a planar view showing a schematic shape of each
micro-channel.
[0039] That is, as one approach for constantly maintaining the
length of each micro-channel, the shape of each micro-channel of
the heat exchanger body, the micro-channel being divided into an
inlet portion, an outlet portion and an intermediate flow channel
portion, may be formed such that the sum of the inlet portion
length (X.sub.1, . . . , X.sub.i, . . . , X.sub.n) and the outlet
portion length (Y.sub.1, . . . , Y.sub.i, . . . , Y.sub.n) is
constant and the lengths (W.sub.1, . . . , W.sub.i, . . . ,
W.sub.n) of the intermediate flow channels are the same, thereby
constantly maintaining the entire length of the micro-channel.
X.sub.i+Y.sub.i+W.sub.i=Constant [Equation 1]
[0040] Here, if a cross section of the micro-channel is different
for each micro-channel in a lengthwise direction, the heat transfer
efficiency may be lowered in spite of the same flow length,
accordingly, it is also preferable to equally maintain the cross
section of each micro-channel.
[0041] In order to increase the efficiency of the heat exchanger,
when designing the channels of the heat exchanger plates to have
the wavy form by adapting a simple parallel option method,
overlapping of the channels may be caused.
[0042] FIG. 5 is an example according to the present invention,
which is a planar view of a micro-channel 15 having gently curved
intermediate flow channels 15a. For the micro-channel 15 shown in
FIG. 5, the overlap between the intermediate flow channels 15a may
not occur, and the total length of each micro-channel 15 is
constant.
[0043] FIG. 6 is an example according to the present invention,
which shows a process of making a wavy intermediate flow
channel.
[0044] As shown in FIG. 6(a), a curved shape to implement is
determined and a first virtual line 71 for the shape is drawn.
[0045] As shown in FIG. 6(b), a second virtual line 74 having the
same shape as that of the first virtual line 71 is drawn with a
desired interval M based upon a centerline 72.
[0046] Then, vertical virtual lines 75 are drawn with a constant
interval W based upon the centerline 72.
[0047] As shown in FIG. 6(c), intersections between the vertical
virtual lines 75 drawn with the constant interval W and the first
and second virtual lines 71 and 74 drawn with the interval M
therebetween are connected.
[0048] As shown in FIG. 6(d), if the edges of the intersections are
processed to be curved, a wavy centerline 77 in a wavy form is
completed. Another centerline having the same shape as the first
centerline 77 is drawn with an interval therebetween as far as a
width of the wavy form, thus to complete one wavy intermediate flow
channel.
[0049] The thusly-constructed micro-channels are shown in FIG. 7.
That is, FIG. 7 is a planar view of the micro-channels according to
the present invention, which shows that micro-channels 16a having
the wavy curved intermediate flow channels can be obtained. As
compared to the linear intermediate flow channel as the example of
the related art, the wavy micro-channel 16a can remarkably improve
the performance of the heat exchanger. In addition, as compared to
the micro-channel having a gently curved portion shown in FIG. 5,
the wavy micro-channel 16a can improve the performance of the heat
exchanger.
[0050] As such, the wavy form ensuring excellent heat transfer as
compared to pressure drop is applied to the heat exchanger body 10
having two curved edges (sides), thereby reducing the sizes of the
curvature profiles of the heat exchanger body 10 and varying
proceeding angles of fluid within the wavy micro-channels according
to positions.
[0051] The constructions and methods of the foregoing embodiments
and advantages of the micro-channel are merely exemplary and are
not to be construed as limiting the present disclosure. The present
teachings can be readily applied to other types of apparatuses.
This description is intended to be illustrative, and not to limit
the scope of the claims. Many alternatives, modifications, and
variations will be apparent to those skilled in the art. The
features, structures, methods, and other characteristics of the
exemplary embodiments described herein may be combined in various
ways to obtain additional and/or alternative exemplary
embodiments.
[0052] As the present features may be embodied in several forms
without departing from the characteristics thereof, it should also
be understood that the above-described embodiments are not limited
by any of the details of the foregoing description, unless
otherwise specified, but rather should be construed broadly within
its scope as defined in the appended claims, and therefore all
changes and modifications that fall within the metes and bounds of
the claims, or equivalents of such metes and bounds are therefore
intended to be embraced by the appended claims.
* * * * *