U.S. patent application number 12/221705 was filed with the patent office on 2009-07-09 for louvered air center for compact heat exchanger.
Invention is credited to Lin-Jie Huang.
Application Number | 20090173479 12/221705 |
Document ID | / |
Family ID | 40843649 |
Filed Date | 2009-07-09 |
United States Patent
Application |
20090173479 |
Kind Code |
A1 |
Huang; Lin-Jie |
July 9, 2009 |
Louvered air center for compact heat exchanger
Abstract
A louvered fin of a heat exchanger assembly includes a louvered
portion having a plurality of first louvers each extending along a
first louver centerline as well as a plurality of second louvers
each extending along a second louver centerline. Each set of louver
centerlines are parallel to one another and disposed side by side
along a respective axis extending transversely to the centerlines.
The first louvers are disposed at a first angle and the second
louvers are disposed at a second angle relative to the respective
axes. The two axes extend parallel to one another and are spaced
from one another in a length direction transverse to the
centerlines and the axes.
Inventors: |
Huang; Lin-Jie; (East
Amherst, NY) |
Correspondence
Address: |
DELPHI TECHNOLOGIES, INC.
M/C 480-410-202, PO BOX 5052
TROY
MI
48007
US
|
Family ID: |
40843649 |
Appl. No.: |
12/221705 |
Filed: |
August 6, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61020048 |
Jan 9, 2008 |
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Current U.S.
Class: |
165/152 |
Current CPC
Class: |
F28D 1/0535 20130101;
F28F 1/128 20130101 |
Class at
Publication: |
165/152 |
International
Class: |
F28D 1/00 20060101
F28D001/00 |
Claims
1. A heat exchanger assembly for dissipating heat comprising: a
plurality of tubes each extending between ends in a length
direction and between sides in a width direction transverse to said
length direction and parallel to and spaced from one another in a
height direction transverse to said length direction and said width
direction for transferring heat from a refrigerant flowing through
said tubes; a plurality of fins each being zigzagged back and forth
between adjacent ones of said tubes in said height direction and
disposed along said length direction between said ends of said
tubes to define an air channel extending between said sides in said
width direction for receiving heat from said tubes; each of said
fins defining at least one louvered portion to divert some of the
air flowing through each of said air channels through said fin and
into an adjacent one of said air channels; said louvered portion
having a plurality of first louvers each extending in said height
direction along a first louver centerline; said first louver
centerlines being parallel to one another and disposed side by side
along a first axis extending in said transverse width direction;
said first louvers disposed at a first angle relative to said
transverse width direction; said louvered portion having a
plurality of second louvers each extending in said height direction
along a second louver centerline; said second louver centerlines
being parallel to one another and disposed side by side along a
second axis extending in said transverse width direction; said
second louvers disposed at a second angle relative to said
transverse width direction; and said second axis extending parallel
to said first axis and spaced from said first axis in said length
direction.
2. The assembly as set forth in claim 1 wherein each of said second
louver centerlines are spaced from corresponding ones of said first
louver centerlines in said length direction by a first distance and
are offset from corresponding ones of said first louver centerlines
in said width direction by a second distance.
3. The assembly as set forth in claim 2 wherein said length
direction is perpendicular to said height direction and said width
direction is perpendicular to said height direction and said length
direction.
4. The assembly as set forth in claim 3 wherein said first distance
and said second distance and said first angle are interrelated
according to a first relationship defined as tan - 1 ( a b )
.noteq. .theta. 1 . ##EQU00001##
5. The assembly as set forth in claim 4 wherein said first distance
and said second distance and said first angle are interrelated
according to a second relationship defined as tan - 1 ( a b ) <
.theta. 1 ##EQU00002## and said first angle and said second angle
are interrelated according to a third relationship defined as
.theta..sub.1<.theta..sub.2.
6. The assembly as set forth in claim 2 wherein said first angle is
equal to said second angle.
7. The assembly as set forth in claim 2 wherein said first angle is
different than said second angle.
8. The assembly as set forth in claim 2 wherein said first louver
centerlines of said first louvers each are spaced equidistant from
one another and second louvers are each spaced equidistant from one
another.
9. The assembly as set forth in claim 7 wherein a difference
between said first angle and said second angle is in a range of 0
to 50% of said first angle.
10. The assembly as set forth in claim 2 wherein said louvered
portion has a plurality of third louvers each extending in said
height direction along a third louver centerline.
11. The assembly as set forth in claim 10 wherein said third louver
centerlines extend parallel to and spaced equidistant from one
another and said third louvers are angled at a third angle relative
to said transverse width direction; each of said third louvers
being disposed side by side along and perpendicular to a third axis
extending parallel to and spaced from said second axis in said
length direction.
12. The assembly as set forth in claim 11 wherein each of said
third louver centerlines are spaced from corresponding ones of said
second louver centerlines in said length direction by said first
distance and are offset from corresponding ones of said second
louver centerlines in said width direction by said second
distance.
13. The assembly as set forth in claim 12 wherein said angles are
equal to one another.
14. A heat exchanger assembly for dissipating heat comprising: a
plurality of tubes each extending between ends in a length
direction and between sides in a width direction and parallel to
and spaced from one another in a height direction for transferring
heat from a refrigerant flowing through said tubes; a plurality of
fins each being zigzagged back and forth between adjacent ones of
said tubes in a height direction transverse to said length
direction and disposed along said length direction between said
ends of said tubes to define air channels in said width direction
transverse to said length direction and height direction for
receiving heat from said tubes; each of said fins defining at least
one louvered portion to divert some of the air flowing through each
of said channels through said fin and into an adjacent one of said
air channels; each louvered portion having a plurality of first
louvers each extending in said height direction along a first
louver centerline; said first louver centerlines being parallel to
and spaced equidistant from one another and disposed at a first
angle relative to said transverse width direction; said first
louver centerlines being disposed side by side along and
perpendicular to a first axis extending transversely to said tubes
in said width direction; said louvered portion having a plurality
of second louvers each extending in said height direction along a
second louver centerline; said second louver centerlines being
parallel to and spaced equidistant from one another and angled at a
second angle relative to said transverse width direction; said
second louver centerlines being disposed side by side along and
perpendicular to a second axis extending parallel to said first
axis and spaced from said first axis in said length direction; said
louvered portion having a plurality of third louvers each extending
in said height direction along a third louver centerline; said
third louver centerlines being parallel to and spaced equidistant
from one another and angled at a third angle relative to said
transverse width direction; said third louvers each being disposed
side by side along and perpendicular to a third axis extending
parallel to and spaced from said second axis in said length
direction; each of said second louver centerlines being spaced from
corresponding ones of said first louver centerlines in said length
direction by a first distance and being offset from corresponding
ones of said first louver centerlines in a width direction by a
second distance; each of said third louver centerlines being spaced
from corresponding ones of said second louver centerlines in said
length direction by said first distance and being offset from
corresponding ones of said second louver centerlines in a width
direction by said second distance; said first distance and said
second distance and said first angle being interrelated according
to a first relationship defined as tan - 1 ( b a ) .noteq. .theta.
1 ; ##EQU00003## and said angles being equal to one another.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] A heat exchanger assembly for dissipating heat and more
specifically, a heat exchanger assembly having fins.
[0003] 2. Description of the Prior Art
[0004] A heat exchanger assembly generally includes a plurality of
tubes each extending parallel to and spaced from one another for
transferring heat from a refrigerant flowing through the tubes. A
plurality of undulating fins zigzag back and forth between adjacent
ones of the tubes to define air channels.
[0005] Each one of the fins typically define at least one louvered
portion which has a plurality of louvers each extending parallel to
one another and disposed along a single axis, referred to as the
louvered air center. Generally, if included the louvers of a second
louvered portion are also disposed along the same single axis. The
louvers are angled relative to the fin surface such that the
louvers divert some of the air flowing through each of the air
channels through the fin and into adjacent air channels.
[0006] Louvered air center performance is critical to the heat
transfer rate of compact heat exchangers, such as radiator,
heaters, condensers, and evaporators. A typical louvered air center
includes a plurality of louvered portions on each fin, e.g., a
leading margin, a turn-around margin, and a trailing margin. The
actual airflow path in the air center can be theoretically divided
into two different flow paths, louver flow and channel flow.
Channel flow is defined as the flow along the air channels. Louver
flow is defined as the flow between the louvers into adjacent air
channels. The greater the percentage of air flowing between the
louvers as louver flow, the greater the heat transfer and airflow
efficiency.
[0007] For a given distance between two groups of louvers, i.e.,
the width of each air channel formed by the zigzagging fin, smaller
louver widths result in a thinner thermal boundary layer which
increases heat transfer for the assembly. On the other hand, the
smaller louver widths also result in a larger gap between two
adjacent groups of louvers, i.e., a larger air channel width, which
results in a higher percentage of channel flow and therefore lower
heat transfer performance. Accordingly, in the current heat
exchanger fin designs, there is an optimum louver width for a given
air channel width wherein performance cannot be further
improved.
[0008] Although the prior heat exchanger assemblies are sufficient
for their intended purposes, there is a continuing need for more
efficient and improved assemblies.
SUMMARY OF THE INVENTION
[0009] The invention includes a louvered portion having a plurality
of first louvers each extending in a height direction along a first
louver centerline as well as a plurality of second louvers each
extending in the height direction along a second louver centerline.
The first louver centerlines are parallel to one another and
disposed side by side along a first axis extending in a width
direction transverse to the height direction and the second louver
centerlines are parallel to one another and disposed side by side
along a second axis extending in the transverse width direction.
The first louvers are disposed at a first angle and the second
louvers are disposed at a second angle relative to the transverse
width direction. The second axis extends parallel to said first
axis and spaced from said first axis in a length direction
transverse to the height direction and the width direction.
[0010] The invention reduces the thermal boundary layer of each
louver which improves performance while simultaneously reducing the
amount of channel flow which also improves performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Other advantages of the present invention will be readily
appreciated, as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings wherein:
[0012] FIG. 1 is a perspective view of a heat exchanger assembly
illustrating two fins each having a plurality of louvered
portions;
[0013] FIG. 2 is an enlarged view of a fin of FIG. 1 illustrating
the first and second louvers of one louvered portion;
[0014] FIG. 3 is a schematic view showing a cross-section of an
alternative embodiment of the fins of FIG. 1 illustrating parallel
first and second louvers;
[0015] FIG. 3A is an enlarged view of area 3A in FIG. 3;
[0016] FIG. 4 is a schematic view showing a cross-section of an
alternative embodiment of the fins of FIG. 1;
[0017] FIG. 5 is a schematic view showing a cross-section of an
alternative embodiment of the fins of FIG. 1 illustrating parallel
first, second, and third louvers;
[0018] FIG. 5A is an enlarged view of area 5A in FIG. 5;
[0019] FIG. 6 is a schematic view showing a cross-section of an
alternative embodiment of the fins of FIG. 1 illustrating
non-parallel first and second louvers;
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0020] Referring to the Figures, wherein like numerals indicate
corresponding parts throughout the several views, a heat exchanger
assembly for dissipating heat is generally shown. As shown in FIG.
1, a plurality of tubes 20 each extend between ends in a length
direction A.sub.L and between sides in a width direction A.sub.W
transverse to the length direction A.sub.L for transferring heat
from a refrigerant flowing through the tubes 20. The tubes 20 are
parallel to one another and spaced from one another in a height
direction A.sub.H transverse to the length direction A.sub.L and
the width direction A.sub.W. The length direction A.sub.L is
perpendicular to the height direction A.sub.H and the width
direction A.sub.W is perpendicular to the height direction A.sub.H
and the length direction A.sub.L.
[0021] A plurality of fins 22 each are zigzagged back and forth in
the height direction A.sub.H between adjacent ones of the tubes 20
for receiving heat from the tubes 20. The fins 22 are disposed
along the length direction A.sub.L between the ends of the tubes 20
to define an air channel 24. The air channels 24 extend between the
sides of the tubes 20 in the width direction A.sub.W.
[0022] Each one of the fins 22 define at least one louvered portion
26 to divert some of the air flowing through each of the air
channels 24, through the fin 22 and into an adjacent one of the air
channels 24.
[0023] As shown in FIG. 2, the louvered portion 26 has a plurality
of first louvers 28 each extending in the height direction A.sub.H
along a first louver centerline CL.sub.1. The first louver
centerlines CL.sub.1 are parallel to one another and are disposed
side by side along a first axis A.sub.1. The first axis A.sub.1
extends in the transverse width direction A.sub.W. The first
louvers 28 are parallel to one another and are all disposed at a
first angle .theta..sub.1 relative to the transverse width
direction A.sub.W.
[0024] The louvered portion 26 also has a plurality of second
louvers 30 each extending in the height direction A.sub.H along a
second louver centerline CL.sub.2. Similarly, the second louver
centerlines CL.sub.2 are parallel to one another and disposed side
by side along a second axis A.sub.2 extending in the transverse
width direction A.sub.W. The second louvers 30 are also parallel to
one another and are all disposed at a second angle .theta..sub.2
relative to the transverse width direction A.sub.W.
[0025] The second axis A.sub.2 extends parallel to the first axis
A.sub.1 and is spaced from the first axis A.sub.1 in the length
direction A.sub.L, as best shown in FIGS. 3-6.
[0026] As best shown in FIGS. 3 and 4, each one of the second
louver centerlines CL.sub.2 is spaced from a corresponding one of
the first louver centerlines CL.sub.1 in the length direction
A.sub.L by a first distance a. Each one of the second louver
centerlines CL.sub.2 is also offset from the corresponding one of
the first louver centerlines CL.sub.1 in the width direction
A.sub.W by a second distance b.
[0027] The first distance a, the second distance b, and the first
angle .theta..sub.1 are interrelated according to a first
relationship defined as tan.sup.-1(a/b).noteq..sub.1. FIGS. 3 and 5
illustrate an embodiment wherein the
tan.sup.-(a/b)>.theta..sub.1. FIGS. 4 and 6 illustrate an
embodiment wherein the tan.sup.-1(a/b)<.theta..sub.1.
[0028] In one embodiment shown in FIG. 4, the first distance a, the
second distance b, and the first angle .theta..sub.1 are
interrelated according to a second relationship defined as
tan.sup.-1(a/b)<.theta..sub.1 and the first angle .theta..sub.1
and the second angle .theta..sub.2 are interrelated according to a
third relationship defined as .theta..sub.1<.theta..sub.2.
[0029] The first angle .theta..sub.1 may be equal to the second
angle .theta..sub.2, as shown in FIGS. 2-5. Alternatively, the
first angle .theta..sub.1 may be different than the second angle
.theta..sub.2, as shown in FIG. 6. If the first angle .theta..sub.1
is different than the second angle .theta..sub.2, as shown in FIG.
6, the difference between the first angle .theta..sub.1 and the
second angle .theta..sub.2 is preferably in the range of 0 to 50%
of the first angle .theta..sub.1.
[0030] The first louver centerlines CL.sub.1 of the first louvers
28 are each spaced equidistant from one another. Similarly, the
second louvers 30 are each spaced equidistant from one another.
[0031] In one embodiment shown in FIG. 5, the louvered portion 26
has a plurality of third louvers 32 each extending in the height
direction A.sub.H along a third louver centerline CL.sub.3. The
third louver centerlines CL.sub.3 extend parallel to one another
and are spaced equidistant from one another. The third louvers 32
are parallel to one another and are all angled at a third angle
.theta..sub.3 relative to the transverse width direction A.sub.W.
Each of the third louvers 32 are disposed side by side along and
perpendicular to a third axis A.sub.3. The third axis A.sub.3
extends parallel to and spaced from the second axis A.sub.2 in the
length direction A.sub.L.
[0032] Each one of the third louver centerlines CL.sub.3 is spaced
from a corresponding one of the second louver centerlines CL.sub.2
in the length direction A.sub.L by the first distance a. Each one
of the third louver centerlines CL.sub.3 is also offset from the
corresponding one of the second louver centerlines CL.sub.2 in the
width direction A.sub.W by the second distance b.
[0033] Each of the third louver centerlines CL.sub.3 are offset
from corresponding ones of the second louver centerlines CL.sub.2
in the width direction A.sub.W by the first distance a and are
spaced from corresponding ones of the second louver centerlines
CL.sub.2 in the length direction A.sub.L by the second distance b.
The angles (.theta..sub.1, .theta..sub.2, .theta..sub.3) may all be
equal to one another, as shown in FIG. 5 or alternatively may be
different (not shown).
[0034] In operation, air flowing through the air channels 24 is
diverted through the louvered portions 26 of the zigzagging fin 22
and into adjacent air channels 24. Because the invention requires
multiple rows of louvers 28, 30, 32 for each louvered portion 26,
the width of each louver may be reduced, reducing the thermal
boundary layer and increasing heat transfer, without reducing the
gap in the length direction A.sub.L between two parallel louvered
portions 26, i.e., without reducing the width of the air channels
24. Accordingly, the invention surpasses the heat transfer of prior
assemblies by decreasing louver width below that of the optimum
width of the prior assemblies while maintaining the same air
channel 24 width.
[0035] While the invention has been described with reference to an
exemplary embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing form the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
* * * * *