U.S. patent application number 09/992312 was filed with the patent office on 2003-05-22 for multi-edge folded louvered fin for heat exchanger.
Invention is credited to Young, Darryl Leigh.
Application Number | 20030094267 09/992312 |
Document ID | / |
Family ID | 25538175 |
Filed Date | 2003-05-22 |
United States Patent
Application |
20030094267 |
Kind Code |
A1 |
Young, Darryl Leigh |
May 22, 2003 |
Multi-edge folded louvered fin for heat exchanger
Abstract
A multi-edge folded louvered fin for a heat exchanger includes a
blank extending longitudinally having a longitudinal axis and
folded in a serpentine configuration having top and bottom base
portions and a fin body extending between adjacent ones of said top
and bottom base portions. The multi-edge folded louvered fin also
includes a plurality of louvers for each fin body extending
outwardly at a first predetermined angle relative to a direction of
air flow entering the heat exchanger. Each of the louvers has a
leading edge and a trailing edge being offset longitudinally
relative to each other. The multi-edge folded louvered fin includes
the fin body being disposed at a second predetermined angle
relative to the direction of air flow entering the heat exchanger.
The multi-edge folded louvered fin further includes the first
predetermined angle opposing the second predetermined angle.
Inventors: |
Young, Darryl Leigh;
(Belleville, MI) |
Correspondence
Address: |
Daniel H. Bliss
Bliss McGlynn & Nolan, P.C.
Suite 600
2075 West Big Beaver Road
Troy
MI
48084
US
|
Family ID: |
25538175 |
Appl. No.: |
09/992312 |
Filed: |
November 19, 2001 |
Current U.S.
Class: |
165/152 ;
165/181 |
Current CPC
Class: |
F28F 1/128 20130101 |
Class at
Publication: |
165/152 ;
165/181 |
International
Class: |
F28D 001/02; F28F
001/20 |
Claims
What is claimed is:
1. A multi-edge folded louvered fin for a heat exchanger
comprising: a blank extending longitudinally having a longitudinal
axis and folded in a serpentine configuration having top and bottom
base portions and a fin body extending between adjacent ones of
said top and bottom base portions; a plurality of louvers for each
said fin body extending outwardly at a first predetermined angle
relative to a direction of air flow entering the heat exchanger,
each of said louvers having a leading edge and a trailing edge
being longitudinally offset with respect to each other; said fin
body being disposed at a second predetermined angle relative to the
direction of air flow entering the heat exchanger; and said first
predetermined angle opposing said second predetermined angle.
2. A multi-edge folded louvered fin as set forth in claim 1 wherein
said blank is generally planar and rectangular in shape.
3. A multi-edge folded louvered fin as set forth in claim 1 wherein
said fin body includes a plurality of apertures extending
therethrough, one of said apertures being disposed between an
adjacent pair of said louvers for air to flow therebetween.
4. A multi-edge folded louvered fin as set forth in claim 1 wherein
said first predetermined angle is from five degrees to fifteen
degrees.
5. A multi-edge folded louvered fin as set forth in claim 1 wherein
said second predetermined angle is from five degrees to fifteen
degrees.
6. A multi-edge folded louvered fin as set forth in claim 1 wherein
said blank is folded in corrugations.
7. A multi-edge folded louvered fin as set forth in claim 1 wherein
said fin is integral, unitary, and formed as one-piece.
8. A multi-edge folded louvered fin for a heat exchanger
comprising: a blank extending longitudinally having a longitudinal
axis and folded in a serpentine configuration having top and bottom
base portions and a fin body extending between adjacent ones of
said top and bottom base portions; a plurality of louvers for each
said fin body extending outwardly at a first predetermined angle
relative to a direction of air flow entering the heat exchanger,
each of said louvers extending in a direction parallel to the
longitudinal axis and being spaced laterally and having a leading
edge and a trailing edge being longitudinally offset with respect
to each other; said fin body being disposed at a second
predetermined angle relative to the direction of air flow entering
the heat exchanger; and said first predetermined angle opposing
said second predetermined angle.
9. A multi-edge folded louvered fin as set forth in claim 8 wherein
said blank is generally planar and rectangular in shape.
10. A multi-edge folded louvered fin as set forth in claim 8
wherein said first predetermined angle is from positive five
degrees to positive fifteen degrees.
11. A multi-edge folded louvered fin as set forth in claim 8
wherein said second predetermined angle is from negative five
degrees to negative fifteen degrees.
12. A multi-edge folded louvered fin as set forth in claim 8
wherein said blank is folded in corrugations.
13. A multi-edge folded louvered fin as set forth in claim 8
wherein said fin is integral, unitary, and formed as one-piece.
14. A multi-edge folded louvered fin as set forth in claim 8
wherein said blank is made of a metal material.
15. A heat exchanger comprising: a plurality of tubes; a plurality
of multi-edge folded louvered fins disposed between each of said
tubes; and each of said multi-edge folded louvered fins comprising
a blank extending longitudinally having a longitudinal axis and
folded in a serpentine configuration having top and bottom base
portions and a fin body extending between adjacent ones of said top
and bottom base portions, a plurality of louvers for each said fin
body extending outwardly at a first predetermined angle relative to
a direction of air flow entering the heat exchanger, each of said
louvers having a leading edge and a trailing edge being
longitudinally offset with respect to each other, said fin body
being disposed at a second predetermined angle relative to the
direction of air flow entering the heat exchanger, and said first
predetermined angle opposing said second predetermined angle.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to heat exchangers
for motor vehicles and, more specifically, to a multi-edge folded
louvered fin for a heat exchanger in a motor vehicle.
[0003] 2. Description of the Related Art
[0004] It is known to provide a louvered fin for use in a heat
exchanger such as an evaporator in a motor vehicle. An example of
such a louvered fin is disclosed in U.S. Pat. No. 5,501,270 to
Young et al. In that patent, the louvered fin typically includes a
generally planar base having a longitudinal axis generally
perpendicular to the direction of air flow entering the heat
exchanger and a transverse axis generally parallel to the direction
of air flow. The axes define a main plane disposed at a
predetermined angle relative to the direction of air flow entering
the heat exchanger. The louvered fin also has a plurality of
apertures for receiving tubes therethrough and a plurality of
louvers disposed on the base extending generally parallel to the
longitudinal axis of the base. The predetermined angle can be
between 140 and 175 degrees to the direction of air flow entering
the heat exchanger. However, the louvers are placed at a zero
degree (0.degree.) angle of attack relative to the air flow.
[0005] Another known fin for a heat exchanger such as an evaporator
is disclosed in U.S. Pat. No. 5,505,257 to Goetz, Jr. In this
patent, a corrugated fin strip for a heat exchanger has interfacing
parallelogram shaped fin panels joined by successive parallel
crests, all fin panels having the same parallelogram shape selected
in accordance with a desired configuration of the heat exchanger.
In one embodiment, the parallel crests extend obliquely between the
longitudinal edges of a rectilinear metal strip from which the fin
strip is formed, and are adapted to be alternatively attached to
the flat face of a heat exchanger tube in oblique relation to
parallel sides of the tube, thereby defining an air flow direction
oblique to the length thereof. However, the fin lacks louvers for
turning the air flow to maximize heat transfer.
[0006] Another known fin for a heat exchanger such as a condenser
is disclosed in U.S. Pat. No. 6,247,527 to Paulman. In this patent,
an improved fin array is an elongated one-piece fin member having
top and bottom base portions with fin sets extending between
adjacent top and bottom base portions. The top and bottom base
portions are generally flat for bonding to the heat exchanger
tubes. Each fin set includes a plurality of individual fins
extending generally perpendicular to a longitudinal length of the
fin member and having side edges that are longitudinally offset
with respect to each other. The offset fin edges provide increased
air flow over the individual fins. However, this fin does not
maximize heat transfer relative to pressure loss.
[0007] Although the above fins have worked for a heat exchanger, it
is desirable to provide a louvered fin for a heat exchanger that
maximizes heat transfer relative to pressure loss. It is also
desirable to provide a multi-edge folded fin for a heat exchanger
that has a minimum drop in airside pressure for increased heat
transfer. Therefore, there is a need in the art to provide a
multi-edge folded louvered fin for a heat exchanger that
outperforms conventional louvered fins in both heat transfer and
air pressure drop.
SUMMARY OF THE INVENTION
[0008] Accordingly, the present invention is a multi-edge louvered
fin for a heat exchanger including a blank extending longitudinally
having a longitudinal axis and folded in a serpentine configuration
having top and bottom base portions and a fin body extending
between adjacent ones of said top and bottom base portions. The
multi-edge folded louvered fin also includes a plurality of louvers
for each fin body extending outwardly at a first predetermined
angle relative to a direction of air flow entering the heat
exchanger. Each of the louvers has a leading edge and a trailing
edge being offset longitudinally relative to each other. The
multi-edge folded louvered fin includes the fin body being disposed
at a second predetermined angle relative to the direction of air
flow entering the heat exchanger. The multi-edge folded louvered
fin further includes the first predetermined angle opposing the
second predetermined angle.
[0009] One advantage of the present invention is that a multi-edge
folded louvered fin for a heat exchanger such as an evaporator is
provided for a motor vehicle. Another advantage of the present
invention is that the multi-edge folded louvered fin has a small
angle on the fin body and an opposing angle on the louvers to
maximize heat transfer relative to pressure loss. Yet another
advantage of the present invention is that the multi-edge folded
louvered is provided for a heat exchanger that has a minimum drop
in airside pressure for increased heat transfer.
[0010] Other features and advantages of the present invention will
be readily appreciated, as the same becomes better understood,
after reading the subsequent description taken in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a multi-edge folded louvered
fin, according to the present invention, illustrated in operational
relationship with a heat exchanger.
[0012] FIG. 2 is a perspective view of a blank gathered into
finished geometry for the multi-edge folded louvered fin of FIG. 1
illustrating folds thereof.
[0013] FIG. 3 is a top view of the multi-edge folded louvered fin
of FIG. 1.
[0014] FIG. 4 is a sectional view taken along line 4-4 of FIG.
3.
[0015] FIG. 5 is an enlarged side view of the multi-edge folded
louvered fin of FIG. 1.
[0016] FIG. 6 is a sectional view taken along line 6-6 of FIG.
5.
[0017] FIG. 7 is an enlarged view of a portion in circle 7 of the
multi-edge folded louvered fin of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0018] Referring to the drawings and in particular FIG. 1, one
embodiment of a heat exchanger 10, such as an evaporator, is shown
for a motor vehicle (not shown). The heat exchanger 10 includes a
plurality of generally parallel-elongated tubes 12 and a header 14
connected to each end of the tubes 12. The heat exchanger 10
includes a fluid inlet 16 for conducting cooling fluid into the
heat exchanger 10 formed in one of the headers 14 and a fluid
outlet 18 for directing fluid out of the heat exchanger 10 formed
in the other header 14. The heat exchanger 10 also includes a
plurality of spacers or multi-edge folded louvered fins, generally
indicated at 20 and according to the present invention, attached an
exterior of each of the tubes 12. The multi-edge folded louvered
fins 20 are disposed between each of the tubes 12. The multi-edge
folded louvered fins 20 serve as a means for conducting heat away
from the tubes 12 while providing additional surface area for
convective heat transfer by air flowing over the heat exchanger 10.
It should be appreciated that, except for the multi-edge folded
louvered fins 20, the heat exchanger 10 is conventional and known
in the art. It should also be appreciated that the multi-edge
folded louvered fins 20 could be used for heat exchangers in other
applications besides motor vehicles.
[0019] Referring to FIGS. 2 through 7, the multi-edge folded
louvered fin 20 starts as a blank 22. The blank 22 is generally
planar and rectangular shape. The blank 22 extends longitudinally
having a longitudinal axis. The blank 22 is made of a metal
material commonly aluminum or copper. The blank 22 is folded in a
serpentine pattern of alternating top and bottom base portions 24
and 26, respectively. A plurality of fin bodies 28 is formed in the
blank 22 extending between and connecting adjacent ones of the top
and bottom base portions 24 and 26. The term "fin body or fin
bodies" as used herein is defined by a centerline through a bank or
set of louvers 30 to be described. The fin bodies 28 are disposed
at a predetermined angle to be described relative to a direction of
air flow entering the heat exchanger 10. Each of the fin bodies 28
includes a plurality of louvers 30 extending outwardly. Each louver
30 is positioned at a predetermined louver angle of approximately
positive five degrees (5.degree.) to approximately positive fifteen
degrees (15.degree.) relative to the airflow while each fin body 28
is positioned at a predetermined fin body angle of approximately
negative five degrees (5.degree.) to approximately negative fifteen
degrees (15.degree.) relative to the airflow. The louvers 30 are
generally planar and rectangular in shape. The louvers 30 extend
longitudinally or generally parallel to a longitudinal axis of the
blank 22. The louvers 30 are cut or lanced and bent out of the
blank 22 to form apertures 32 for air to flow therebetween. The
louvers 30 are spaced laterally at a relatively small or
predetermined louver pitch such as 0.8 millimeters (mm) to 1.0 mm
to enhance heat transfer. It should be appreciated that the
included angle between the louver 30 and fin body 28 is
approximately ten degrees (10.degree.) to approximately thirty
degrees (30.degree.). It should also be appreciated that the
louvers 30 enhance heat transfer performance. It should further be
appreciated that the top and bottom base portions 24 and 26 are
brazed to the tubes 12.
[0020] Referring to FIGS. 2 and 5, each of the louvers 30 has a
leading edge 34 and a trailing edge 36 longitudinally offset with
respect to the leading edges 34 and trailing edges 36 of all of the
other louvers 30 in a fin body 28. The offset positioning of the
louvers 30 maximizes heat transfer of the louvers 30 with the
ambient air because the offset leading and trailing edges 34 and 36
provide maximum exposure to the air and the louvers 30 do not block
air with respect to each other. It should be appreciated that for
maximum heat transfer efficiency the louvers 30 should not be
parallel to the on-coming air stream.
[0021] As illustrated in FIG. 4, each of the louvers 30 on each of
the fin bodies 28 is disposed at a predetermined angle, .PHI., of
between approximately five (+5.degree.) to approximately fifteen
positive degrees (+15.degree.) relative to the direction of the air
flow A or oncoming air stream entering a front face of the heat
exchanger 10. In addition, each fin body 28 is disposed at an angle
.theta. of between approximately five (-5.degree.) to approximately
fifteen negative degrees (-15.degree.) relative to the direction of
the air flow A or oncoming air stream entering a front face of the
heat exchanger 10. It should be appreciated that the included angle
between the louver 30 and fin body 28 is approximately ten degrees
(10.degree.) to approximately thirty degrees (30.degree.). It
should also be appreciated that by placing the fin bodies 28 at an
angle to the oncoming air stream results in low pressure losses and
air flow passes between each of the louvers 30 very easily,
increasing the number of louvers 30 contacted by the air stream,
thereby increasing the overall effectiveness of the heat exchanger
10 while decreasing the pressure building across the heat exchanger
10. It should further be appreciated that the angle of the louvers
30 opposes the angle on the fin bodies 28, thereby maximizing heat
transfer relative to pressure loss.
[0022] The multi-edge folded louvered fin 20 is formed as a
monolithic structure being integral, unitary, and one-piece. The
multi-edge folded louvered fin 20 is formed by a conventional roll
forming process as disclosed in U.S. Pat. No. 6,247,527, the
disclosure of which is hereby incorporated by reference to form the
blank 22 into a corrugated or folded style of a typical louvered
fin as illustrated in FIG. 2.
[0023] The present invention has been described in an illustrative
manner. It is to be understood that the terminology, which has been
used, is intended to be in the nature of words of description
rather than of limitation.
[0024] Many modifications and variations of the present invention
are possible in light of the above teachings. Therefore, within the
scope of the appended claims, the present invention may be
practiced other than as specifically described.
* * * * *