U.S. patent application number 12/385756 was filed with the patent office on 2009-12-03 for heat exchanger.
This patent application is currently assigned to KOREA ATOMIC ENERGY RESEARCH INSTITUTE. Invention is credited to Jae-Eun Cha, Dong-Eok Kim, Moo-Hwan Kim, Seong-O Kim.
Application Number | 20090294113 12/385756 |
Document ID | / |
Family ID | 41378342 |
Filed Date | 2009-12-03 |
United States Patent
Application |
20090294113 |
Kind Code |
A1 |
Cha; Jae-Eun ; et
al. |
December 3, 2009 |
Heat exchanger
Abstract
Disclosed is a heat exchanger. The heat exchanger includes a
plurality of plates superimposed on one another, and a plurality of
heat transfer fins formed on the plurality of plates, and shaped
into an airfoil, wherein a channel of a fluid between the
superimposed plates is formed to perform a heat exchange.
Inventors: |
Cha; Jae-Eun; (Seo-gu,
KR) ; Kim; Seong-O; (Yuseong-gu, KR) ; Kim;
Dong-Eok; (Pohang-si, KR) ; Kim; Moo-Hwan;
(Pohang-si, KR) |
Correspondence
Address: |
THE NATH LAW GROUP
112 South West Street
Alexandria
VA
22314
US
|
Assignee: |
KOREA ATOMIC ENERGY RESEARCH
INSTITUTE
DAEJEON
KR
KOREA HYDRO & NUCLEAR POWER CO., LTD.
SEOUL
KR
|
Family ID: |
41378342 |
Appl. No.: |
12/385756 |
Filed: |
April 17, 2009 |
Current U.S.
Class: |
165/185 |
Current CPC
Class: |
F28D 9/0037 20130101;
F28F 2250/02 20130101; F28F 3/048 20130101; F28F 13/06
20130101 |
Class at
Publication: |
165/185 |
International
Class: |
F28F 3/00 20060101
F28F003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 3, 2008 |
KR |
10-2008-0051931 |
Claims
1. A heat exchanger, comprising: a plurality of plates superimposed
on one another; and a plurality of heat transfer fins formed on the
plurality of plates, and shaped into an airfoil, wherein a channel
of a fluid between the superimposed plates is formed to perform a
heat exchange.
2. The heat exchanger of claim 1, wherein the airfoil is
symmetrical with respect to a chord line of the heat transfer
fins.
3. The heat exchanger of claim 2, wherein the chord line of the
plurality of heat transfer fins is positioned on a straight line
being parallel with a flowing direction of the fluid.
4. The heat exchanger of claim 3, wherein the plurality of heat
transfer fins forms a fin column included on a single straight line
being parallel with the flowing direction of the fluid, a plurality
of fin columns being formed.
5. The heat exchanger of claim 4, wherein a leading edge of the
heat transfer fin included in the single fin column and another
leading edge of another fin column adjacent to the single fin
column are disposed on different straight lines each being
perpendicular to the flowing direction of the fluid.
6. The heat exchanger of claim 1, wherein the plurality of plates
are combined with each other in a diffusion bonding.
7. The heat exchanger of claim 1, wherein chord lines of the
plurality of heat transfer fins disposed on different plates being
adjacent to each other are disposed at a predetermined angle.
8. The heat exchanger of claim 1, wherein the heat transfer fins
disposed on different plates being adjacent to each other are
disposed in an opposite direction to each other.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent
Application No. 10-2008-0051931, filed on Jun. 3, 2008, in the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to a heat exchanger, and more
particularly, to a heat exchanger in which a channel type is
changed into a fin structure to increase a heat transfer area, and
the fin is formed into an airfoil shape to minimize a pressure drop
due to the fin structure, thereby increasing a heat flowing
performance.
[0004] 2. Description of the Related Art
[0005] In the Republic of Korea, with an economical and social
change due to a switchover to a highly industrialized society,
energy consumption and emission of greenhouse gases such as carbon
dioxide have been rapidly increased. Currently, advanced countries
have strongly requested that the Republic of Korea, that is, one of
Organisation for Economic Co-operation and Development (OECD)
members and a front-runner in developing countries, reduce
greenhouse gas emission. Accordingly, there arises a need for
actively attempting a method of reducing the greenhouse gas
emission. A heat exchanger having a concept of a heat transfer
device such as a condenser, an evaporator, a radiator, and the like
may be utilized in various fields such as industry, transportation,
households, and the like. In France, a huge amount of energy is
consumed whereby in one year about 80% to 90% of primary energy has
been circulated through a heat exchanger. Accordingly, when
increasing efficiency of the heat exchanger, consumed energy may be
significantly reduced, and at the same time generation of carbon
dioxide may be reduced.
[0006] Therefore, there arises a need for an intensive heat
exchanger that reduces an overall volume of the heat exchanger
while maintaining a required heat flowing performance. A method of
increasing convective heat transfer to promote heat transfer of the
heat exchanger may be roughly classified into a passive method and
an active method. The active method in which a pulsation is applied
to a working fluid or an additive is applied to a fluid may be
effective in all flowing areas, however, may be restrictively used
because separate equipment is additionally needed, and energy
requiring for driving the separate equipment is required to be
supplied.
[0007] Conversely, the passive method may be an ordinary method of
increasing efficiency through a slight change in an existing design
such as manipulation of a heat transfer surface. In the most
general method of operating a fluid channel and the heat transfer
surface, and using a fin, an offset fin, a louvered fin, a serrated
fin, and the like have been used, and also a technique in which a
rib is attached on the heat transfer surface or the heat exchanger
surface formed into a groove or corrugate shape is used to promote
generation of turbulence has been introduced.
[0008] A conventional heat exchanger will be herein briefly
described. FIG. 1 is a perspective view illustrating heat transfer
members of the conventional heat exchanger, which are superimposed
for heat exchange.
[0009] As illustrated in FIG. 1, the conventional heat exchanger is
formed such that a plurality of metal plate-heat exchange members
10 are superimposed on one another to be combined with each other,
and fluid channels 11 are formed between the plurality of metal
plate-heat exchange members 10.
[0010] In the conventional heat exchanger, the fluid channels
shaped into a zigzag shape are formed on the metal plate-heat
exchange members 10 to increase a heat transfer area, and a heat
exchange is performed between two heat exchange fluids of a high
temperature side and a low temperature side between the metal
plate-heat exchange members 10.
[0011] In this instance, to maintain a heat flowing performance and
reduce a volume, a size of the fluid channels 11 for heat exchange
is reduced to be about 1 mm, and the fluid channels 11 are disposed
in a zigzag type to thereby enable a heat transfer to be
performed.
[0012] However, the conventional heat exchanger has problems which
will be described in detail as below.
[0013] First, a pressure drop may significantly increase within the
heat exchanger due to a reduction in the size of the fluid
channel.
[0014] Second, a channel through which a heat exchange fluid flows
may be lengthened due to the zigzag shape, and a pressure drop of
the heat exchange fluid may increase due to a vortex flow generated
in a curved part made for mixing the fluid.
[0015] Third, an energy loss may occur due to the above-mentioned
pressure drop, the vortex, and a swirl.
[0016] Fourth, a power of a pump may increase when replenishing the
pressure drop, and an installation cost or operation cost may
increase as a result.
SUMMARY
[0017] An aspect of the present invention provides a heat exchanger
that may prevent a pressure drop while increasing a thermal
efficiency regardless of a size of a channel.
[0018] An aspect of the present invention provides a heat exchanger
that may change a disposition of a heat transfer fin to prevent a
pressure drop of a fluid.
[0019] An aspect of the present invention provides a heat exchanger
that may minimize an energy loss.
[0020] An aspect to the present invention provides a heat exchanger
that may minimize a pressure drop, and enable a heat exchange fluid
to flow using relatively less power of a pump, thereby reducing an
installation cost and operation cost.
[0021] According to an aspect of the present invention, there is
provided a heat exchanger, including: a plurality of plates
superimposed on one another; and a plurality of heat transfer fins
formed on the plurality of plates, and shaped into an airfoil,
wherein a channel of a fluid between the superimposed plates is
formed to perform a heat exchange.
[0022] In this instance, the airfoil may be symmetrical with
respect to a chord line of the heat transfer fins, and the chord
line of the plurality of heat transfer fins may be positioned on a
straight line being parallel with a flowing direction of the
fluid.
[0023] Also, the plurality of heat transfer fins may form a fin
column included on a single straight line being parallel with the
flowing direction of the fluid. In this instance, a plurality of
fin columns may be formed.
[0024] Also, a leading edge of the heat transfer fin included in
the single fin column and another leading edge of another fin
column adjacent to the single fin column may be disposed on
different straight lines each being perpendicular to the flowing
direction of the fluid.
[0025] Also, the plurality of plates may be combined with each
other in a diffusion bonding.
[0026] Also, chord lines of the plurality of heat transfer fins
disposed on different plates being adjacent to each other may be
disposed at a predetermined angle, and the heat transfer fins
disposed on different plates being adjacent to each other may be
disposed in an opposite direction to each other.
[0027] Additional aspects, features, and/or advantages of the
invention will be set forth in part in the description which
follows and, in part, will be apparent from the description, or may
be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] These and/or other aspects, features, and advantages of the
invention will become apparent and more readily appreciated from
the following description of exemplary embodiments, taken in
conjunction with the accompanying drawings of which:
[0029] FIG. 1 is a perspective view illustrating heat transfer
members of a conventional heat exchanger, which are superimposed
for heat exchange;
[0030] FIG. 2 is a perspective view illustrating a heat exchanger
according to example embodiments of the present invention;
[0031] FIG. 3 is an exploded perspective view illustrating a
plurality of plates of a heat exchanger according to example
embodiments of the present invention;
[0032] FIG. 4 is a perspective view illustrating a plate of FIG.
3;
[0033] FIG. 5 illustrates a general airfoil;
[0034] FIG. 6 illustrates a heat transfer fin according to example
embodiments of the present invention;
[0035] FIG. 7 illustrates a disposition of heat transfer fins
according to example embodiments of the present invention;
[0036] FIG. 8 illustrates a heat exchanger including a heat
transfer fin shaped into an airfoil of a case 1;
[0037] FIG. 9 illustrates a heat exchanger including a heat
transfer fin shaped into an airfoil of a case 2;
[0038] FIG. 10 illustrates a heat exchanger including a heat
transfer fin shaped into an airfoil of a case 3; and
[0039] FIG. 11 illustrates an analysis result of three-dimensional
numerical values of a heat transfer and a pressure drop with
respect to a conventional printed circuit heat exchanger and a heat
exchanger with heat transfer fins according to example embodiments
of the present invention.
DETAILED DESCRIPTION
[0040] Reference will now be made in detail to exemplary
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings, wherein like reference
numerals refer to the like elements throughout. Exemplary
embodiments are described below to explain the present invention by
referring to the figures.
[0041] FIG. 2 is a perspective view illustrating a heat exchanger
according to example embodiments of the present invention, FIG. 3
is an exploded perspective view illustrating a plurality of plates
200 of a heat exchanger according to example embodiments of the
present invention, and FIG. 4 is a perspective view illustrating a
plate of FIG. 3.
[0042] The heat exchanger includes a housing 100 receiving the
plurality of plates 200 therein, a header portion 105 disposed on
both sides of the housing 100, inflow pipes 111 and 121 of a heat
exchange fluid, and outflow pipes 112 and 122 of the heat exchange
fluid. In this instance, the plurality of plates 200 includes a
heat transfer fin 210 formed thereon.
[0043] In the heat exchanger, the heat exchange fluid enters the
inflow pipes 111 and 121 by a pump (not shown), a heat transfer is
performed by means of the plurality of plates 200 and the heat
transfer fin 210, and the heat exchange fluid flows out from the
outflow pipes 112 and 122. Here, the heat exchange fluid may be
preferably supercritical carbon dioxide, however the present
invention is not limited thereto.
[0044] A plurality of plates 200 are provided, and superimposed on
one another as illustrated in FIG. 3. In this instance, the
plurality of plates 200 may be made of a stainless steel plate or a
metal material being several millimeters thick, and combined with
each other using a diffusion bonding scheme.
[0045] Specifically, due to a principle in that atoms are moved in
a bonding surface between the plurality of plates 200 by means of a
high pressure generated by an exerted external power to thereby
enable the bonding between the plurality of plates to be performed,
the plurality of plates 200 are combined with each other, and
easily used due to its relatively high tolerance to a high
temperature and high pressure.
[0046] A plurality of heat transfer fins 210 are formed on the
plurality of plates 200, and shaped into an airfoil. Also, the heat
transfer fin 210is protrusively formed on the plurality of plates
200, and thereby a channel between the plurality of plates 200 is
formed, when the plurality of plates 200 are combined with each
other. The channel is disposed to enable the heat exchange fluid to
flow in other parts of the plate other than the heat transfer fin
210, so that a heat transfer is performed through the plurality of
plates 200 and the heat transfer fin 210 to thereby enable a heat
exchange to be preformed. Specifically, a channel (A) is formed by
means of the plurality of plates 200 and the heat transfer fin 210,
and the heat exchange fluid is guided to flow along the channel
A.
[0047] In this instance, another heat transfer fin 210 formed on
another plate being adjacent to the plurality of plates 200 is
disposed in a different direction. That is, the heat exchange
fluids interposing the plurality of plates 200 are required to flow
in different directions from each other, and a more effective heat
exchange is performed as a result. However, the heat transfer fin
210 is required to be disposed in a direction capable of minimizing
a pressure drop with respect to flowing of the heat exchange fluid.
Accordingly, preferably, a leading edge 217 (see FIG. 5) of the
heat transfer fin 210 is disposed to correspond to a flowing
direction of the heat exchange fluid, and a chord line 215 (see
FIG. 5) of the heat transfer fin 210 is arranged in an identical
direction to the flowing direction of the heat exchange fluid.
[0048] According to the present example embodiment, the leading
edge 217 of the heat transfer fin 210 on a plate and another
leading edge of the heat transfer fin on another plate adjacent to
the plate are disposed in opposite directions with a difference of
180 degrees. Specifically, when the heat exchange fluids
interposing the single plate flow in opposite directions, the heat
transfer fin 210 may be disposed along the flowing direction of the
heat exchange fluid.
[0049] According to the present example embodiment, the heat
exchange fluids interposing the single plate flow in opposite
directions with the difference of 180 degrees, however the present
invention is not limited thereto. For example, the flowing
directions of the heat exchange fluids may be provided at a
predetermined angle with respect to the plate, and the heat
transfer fin 210 may be disposed to correspond to the flowing
direction.
[0050] In this instance, the airfoil may be shaped into a
cross-sectional area of a wing, and used in academically defining
any cross-sectional area such as a wing, an aileron, an elevator,
and a rudder of an aircraft. The airfoil may need aerodynamic
effects to lift a heaver than air aircraft, that is, the airfoil
may need a great upward force and a less reaction. To increase the
upward force, the airfoil may be formed into a streamline having a
round upper surface and a sharp tip, however, according to the
present invention, the heat transfer fin 210 may be formed into the
airfoil shape capable of reducing the reaction without generation
of the upward force.
[0051] Here, the heat transfer fin 210 shaped into the airfoil will
be described in detail with reference to FIGS. 5 to 6.
[0052] FIG. 6 illustrates a heat transfer fin according to example
embodiments of the present invention, and FIG. 7 illustrates a
disposition of heat transfer fins according to example embodiments
of the present invention.
[0053] As illustrated in FIG. 5, the airfoil includes the leading
edge 217, a trailing edge 218 the chord line 215, a lower camber
213, an upper camber 212, and an average camber line 211.
[0054] The chord line 215 may designate a straight line connecting
the leading edge 217 and the trailing edge 218, the lower camber
213 may designate a distance from the chord line 215 to a lower
surface, and the upper camber 212 may designate a distance from the
chord line 215 to an upper surface.
[0055] In this instance, the average camber line may designate a
center line of a thickness, that is, an average line between the
upper camber 212 and the lower camber 213. A front end of the
average camber line 211 may designate the leading edge 217 and a
rear end thereof may designate the trailing edge 218.
[0056] In general, the airfoil may be expressed in a naming method
such as NACA XXXX, wherein NACA designates a National Advisory
Committee for Aeronautics-series airfoil, a first numeral of X is a
value in which a size of a maximum average camber is expressed
using a percentage of the chord, a second numeral of X is a value
in which a location of the maximum average camber is expressed
using a percentage of tens of the chord, and third and fourth
numerals of XX are values in which a size of a maximum thickness
216 is expressed using a percentage of the chord.
[0057] In this instance, the shape of the airfoil of the heat
transfer fin 210 may be preferably symmetrical with respect to the
chord line 215. More specifically, when the upper camber 212 and
lower camber 213 of the airfoil are the same, the airfoil may be
referred to as a symmetrical airfoil. In the symmetrical airfoil
having the same upper camber 212 and lower camber 213, the average
camber line may be the same as the chord line. Specifically, only a
concept of the maximum thickness 216 may exist without concepts of
the camber and maximum average camber. Thus, the symmetrical
airfoil may be expressed as NACA 00XX, which is referred to as NACA
00-series, and an NACA 00-series airfoil may designate the
symmetrical airfoil as a result. For example, NACA 0009 and NACA
0012 as the symmetrical airfoil may respectively express an airfoil
with a maximum thickness of 9% of the chord, and an airfoil with a
maximum thickness of 12% of the chord.
[0058] Here, a direction and disposition of the heat transfer fin
210 will be described in detail with reference to FIG. 7. FIG. 7
illustrates a disposition of a heat transfer fin according to
example embodiments of the present invention.
[0059] The chord line 215 of the heat transfer fin 210 is disposed
on a straight line being parallel with a flowing direction (D) of
the heat exchange fluid. That is, the heat transfer fin 210 is
disposed in a direction capable of minimizing a resistance with
respect to the flowing of the heat exchange fluid. As a result, a
heat exchange is effectively performed by means of the heat
exchange fluid, and a pressure drop is minimized.
[0060] Also, the heat transfer fin 210 may form a plurality of fin
columns 250 disposed in a row with respect to the flowing direction
of the heat exchange fluid. In this instance, the heat transfer fin
210 included in the fin column 250 is disposed on a straight line
being parallel with the flowing direction of the heat exchange
fluid.
[0061] In this instance, the leading edge 217 of the heat transfer
fin 210 included in the single fin column 250 and another leading
edge of another heat transfer fin 210 included in another fin
column 250 adjacent to the single fin column 250 may be disposed on
straight lines B or C different from each other each being
perpendicular to the flowing direction (D) of the heat exchange
fluid. Specifically, leading edges of other heat transfer fins
being adjacent to and parallel with the heat transfer fin 210 may
be disposed on different straight lines being perpendicular to the
flowing direction of the heat exchange fluid, thereby minimizing a
pressure drop of the heat exchange fluid and effectively performing
a heat exchange.
[0062] Here, the pressure drop and the heat transfer rate may be
adjusted according to a number of the heat transfer fins 210 and a
disposition density of the heat transfer fins 210, which will be
described in detail with reference to FIGS. 8 to 10.
[0063] FIG. 8 illustrates a heat exchanger including a heat
transfer fin shaped into an airfoil of a case 1, FIG. 9 illustrates
a heat exchanger including a heat transfer fin shaped into an
airfoil of a case 2, FIG. 10 illustrates a heat exchanger including
a heat transfer fin shaped into an airfoil of a case 3, and FIG. 11
illustrates an analysis result of three-dimensional numerical
values of a heat transfer and a pressure drop with respect to a
conventional printed circuit heat exchanger and a heat exchanger
with heat transfer fins according to example embodiments of the
present invention.
[0064] In the case 1 of FIG. 8, the leading edge 217 of the heat
transfer fin 210 included in a fin column 250 is disposed on a
straight line on which a trailing edge of a heat transfer fin
included in a fin column 251 adjacent to the fin column 250 is
located.
[0065] In the case 2 of FIG. 9, the leading edge 217 of the heat
transfer fin 210 included in a fin column 250 is disposed on a
straight line through which a point of 1/2 of the chord line 215 of
a heat transfer fin 210 included in a fin column 251 adjacent to
the fin column 250 passes.
[0066] In the case 3 of FIG. 10, the leading edge 217 of the heat
transfer fin 210 included in a fin column 250 is disposed on a
straight line through which a point of 1/3 of the chord line 215 of
a heat transfer fin 210 included in a fin column 251 adjacent to
the fin column 250, starting from the leading edge of the heat
transfer fin 210, passes.
[0067] Specifically, in FIG. 8 to FIG. 10, the disposition density
of the heat transfer pin 210 becomes denser. That is, locations of
leading edges of the heat transfer fins 210 included in different
fin columns are adjusted to change a degree of density of the heat
transfer fin 210, and Table 1 below shows an obtained analysis
result of the heat exchanger as a result. For reference, according
to the present invention, three plates are superimposed on one
another.
TABLE-US-00001 TABLE 1 classification Pressure drop Heat transfer
rate Note Case 1 262.5 Pa 92.36 Case 2 425 Pa 95.88 Case 3 635 Pa
101.22 PCHE 8924 Pa 100.39 Conventional printed circuit heat
exchanger
[0068] As shown in Table 1, in the heat exchangers including the
heat transfer fin 210 shaped into the airfoils of the cases 1 and
2, the pressure drop is significantly reduced and a total heat
transfer rate is relatively low in comparison with that in the
conventional printed circuit heat exchanger. The heat exchanger
including the heat transfer fin 210 shaped into the airfoil of the
case 3 shows nearly the same heat transfer amount as that in the
conventional printed circuit heat exchanger, and also shows a low
pressure drop corresponding to 1/14 of the pressure drop in the
conventional printed circuit heat exchanger.
[0069] That is, the degree of density of the heat transfer fin 210
may be adjusted to enable the heat exchanger to control the
pressure drop while maintaining the heat transfer amount.
[0070] As described above, according to the present invention,
there is provided a heat exchanger that may change a channel type
into a fin structure to increase a thermal efficiency regardless of
a size of a channel, and may include a fin shaped into an airfoil
to prevent a pressure drop.
[0071] According to the present invention, there is provided a heat
exchanger that may change a direction or shape of a heat transfer
fin to correspond to a channel of a fluid, thereby preventing a
pressure drop of the fluid.
[0072] According to the present invention, there is provided a heat
exchanger that may reduce occurrence of a pressure drop, a vortex
flow, and a turning flow in a channel of a fluid, thereby
minimizing an energy loss.
[0073] According to the present invention, there is provided a heat
exchanger that may minimize a pressure drop, thereby enabling a
heat exchange fluid to flow using relatively less pump power, and
reducing an installation cost and operation cost as a result.
[0074] According to the present invention, there is provided a heat
exchanger that may control a pressure drop while maintaining a heat
transfer amount through a simple change in a disposition of a heat
transfer fin.
[0075] Although a few exemplary embodiments of the present
invention have been shown and described, the present invention is
not limited to the described exemplary embodiments. Instead, it
would be appreciated by those skilled in the art that changes may
be made to these exemplary embodiments without departing from the
principles and spirit of the invention, the scope of which is
defined by the claims and their equivalents.
* * * * *