U.S. patent application number 11/810944 was filed with the patent office on 2008-12-11 for flat tube heat exchanger.
Invention is credited to Joseph Durdel, Kevin Gurley, James Siemer, Michael Warkins.
Application Number | 20080302518 11/810944 |
Document ID | / |
Family ID | 40094783 |
Filed Date | 2008-12-11 |
United States Patent
Application |
20080302518 |
Kind Code |
A1 |
Durdel; Joseph ; et
al. |
December 11, 2008 |
Flat tube heat exchanger
Abstract
A flat tube heat exchanger is provided including a first flat
side and a second flat side opposite the first flat side joined
together by two opposing sides. At least one internal partition
defines a flow duct within the interior of the heat exchanger. A
bend is provided in the plane substantially defined by the first
flat side.
Inventors: |
Durdel; Joseph; (Sigel,
IL) ; Gurley; Kevin; (Effingham, IL) ; Siemer;
James; (Effingham, IL) ; Warkins; Michael;
(Vernon Hills, IL) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE;NBC Tower
Suite 3600, 455 N. Cityfront Plaza Drive
Chicago
IL
60611-5599
US
|
Family ID: |
40094783 |
Appl. No.: |
11/810944 |
Filed: |
June 7, 2007 |
Current U.S.
Class: |
165/148 |
Current CPC
Class: |
F28F 1/025 20130101;
F28D 1/0478 20130101; F28F 1/22 20130101; F28F 1/32 20130101; F28D
1/0473 20130101; F28F 1/022 20130101; F25B 39/00 20130101 |
Class at
Publication: |
165/148 |
International
Class: |
F28D 1/00 20060101
F28D001/00 |
Claims
1. A one piece flat tube heat exchanger comprising: a first flat
side and a second flat side opposite the first flat side, the first
flat side and the second flat side joined together by two opposing
sides, at least one internal partition to define a flow duct
interconnecting the first flat side and the second flat side, the
flat tube heat exchanger having a bend in a plane substantially
defined by the first flat side whereby a flat tube heat exchanger
is formed with the bend portion formed substantially coplanar with
the first flat side.
2. The flat tube heat exchanger of claim 1 wherein the two opposing
sides are rounded.
3. The flat tube heat exchanger of claim 1 wherein the flat tube
heat exchanger has a serpentine pattern.
4. The flat tube heat exchanger of claim 1 wherein the bend forms a
U-shape.
5. The flat tube heat exchanger of claim 1 wherein the flat tube
heat exchanger has a helical pattern.
6. The flat tube heat exchanger of claim 1 wherein the flat tube
heat exchanger has a layered pattern.
7. The flat tube heat exchanger of claim 6 wherein the flat tube
heat exchanger has a layered pattern that is generally
symmetric.
8. The flat tube heat exchanger of claim 1 wherein the flat tube
heat exchanger further comprises another bend in a plane defined by
at least one of the two opposing sides.
9. The flat tube heat exchanger of claim 8 wherein the flat tube
heat exchanger further comprises a plurality of fins.
10. A flat tube heat exchanger, comprising: a single one piece
element including a first flat side and a second opposed flat side
joined together by two opposing sides, at least one internal
partition to define a flow duct, the flat tube heat exchanger
having a width axis defined by the first flat side and the second
flat side and a height axis defined by the two opposing sides, the
flat tube heat exchanger having a U-shaped bend extending
substantially around the height axis.
11. The flat tube heat exchanger of claim 10 wherein the two
opposing sides are rounded.
12. The flat tube heat exchanger of claim 10 wherein the flat tube
heat exchanger has a serpentine pattern.
13. The flat tube heat exchanger of claim 10 wherein the flat tube
heat exchanger has a helical pattern.
14. The flat tube heat exchanger of claim 10 wherein the flat tube
heat exchanger has a layered pattern.
15. The flat tube heat exchanger of claim 14 wherein the flat tube
heat exchanger has a layered pattern that is generally
symmetric.
16. The flat tube heat exchanger of claim 10 wherein the flat tube
heat exchanger further comprises another bend extending around the
width axis.
17. The flat tube heat exchanger of claim 16 wherein the flat tube
heat exchanger further comprises a plurality of fins.
18. The flat tube heat exchanger of claim 10 wherein the flat tube
heat exchanger is formed.
19. A refrigerator, comprising: a flat tube heat exchanger tube
formed as a one piece element including a first flat side and a
second opposed flat side joined together by two opposing sides, at
least one internal partition to define a flow duct, the flat tube
heat exchanger having a U-shaped bend in the plane substantially
defined by the first flat side.
20. The refrigerator of claim 19 wherein the bend forms a U-shape.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of heat
exchangers. More specifically, the present invention relates to a
flat tube heat exchanger having a bend in the plane of a flat side
of the tube.
BACKGROUND OF THE INVENTION
[0002] Heat exchanger coils have been used for many years in
various refrigeration systems. Heat exchanger coils have
traditionally been formed with round tubing. The coils can be
configured in variety of shapes to suit the needs of a particular
application. One example of the use of such heat exchanger coils is
in refrigerators or reach-in coolers for presenting food and/or
beverages items to customers while maintaining the food and/or
beverage items in a refrigerated environment. Such reach-in coolers
can include a shelf on which food items are stored. In one
conventional practice, a heat exchanger coil of round tubing is
connected to the bottom of the shelf/plate on which the
food/beverage items are stored. A suitable refrigerant is passed
through the heat exchanger to act as a heat exchange medium. The
refrigerant in the heat exchange coil absorbs heat from the shelf
and causes the refrigerant to evaporate as it passes through the
heat exchanger. As a result, the temperature of the shelf is
reduced, thereby keeping the items placed on the top surface
thereof at a reduced temperature.
[0003] Heat exchanger coils having a flat tube configuration have
also been formed for particular applications. Flat tube heat
exchanger coils have been formed with two opposing flat sides and
two interconnecting sides. In order to form a heat exchanger
structure, a bend was placed in a plane defined by the
interconnecting sides. It was understood that the bend would have
to be formed in this manner because the material forming the tube
would fracture if the bend was placed in a plane formed by the
opposing flat sides.
[0004] Improvements have been sought in many heat exchangers which
decrease the amount of necessary refrigerant materials. Also,
improvements have been sought which would increase the heat
transfer surface area of the heat exchanger coil in order to
increase the efficiency of the system. As a result, there is a need
for an improved heat exchanger tubing that assists in increasing
the efficiency of the system while not adding undesirable features
such as air restriction and excess material.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a flat tube heat
exchanger tube that has improved efficiencies over heat exchanger
tubes of the past. The present invention provides a flat tube heat
exchanger that increases the heat transfer surface area while
minimizing the internal cross-section of the tube, thereby
minimizing the use of refrigerant within the heat exchanger tube.
The flat tube heat exchanger of the present invention forms a novel
shape offering improved air flow capabilities over the heat
exchanger and a larger primary heat transfer surface for improved
efficiency. The present invention also provides for an increased
usable primary surface area, reduced secondary surface requirement,
reduced air restriction, fewer braze joints, and reduced thermal
resistance.
[0006] The present invention provides in one aspect, a flat tube
heat exchanger including a first flat side and a second flat side
opposite the first flat side joined together by two opposing sides.
At least one internal partition defines a flow duct within the
interior of the heat exchanger. A bend is provided in the plane
substantially defined by the first flat side.
[0007] The present invention provides, in another aspect, a flat
tube heat exchanger formed from a single one piece element having a
first flat side and a second flat side opposite the first flat side
and joined together by two opposing sides. At least one internal
partition is provided to define a flow duct. The first flat side
and second flat side define a width axis. The two opposing sides
define a height axis. The flat tube heat exchanger has a U-shaped
bend extending substantially around the height axis.
[0008] The present invention, together with attendant objects and
advantages, will be best understood with reference to the detailed
description below in connection with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an illustration of a bottom perspective view of a
flat tube heat exchanger connected to a plate according to an
embodiment of the invention;
[0010] FIG. 2 is a bottom view of the flat tube heat exchanger and
plate of FIG. 1;
[0011] FIG. 3 is a perspective view of the flat tube heat exchanger
of FIGS. 1 and 2 without the plate;
[0012] FIG. 4 is a cross-sectional view of the flat tube heat
exchanger of FIG. 1;
[0013] FIG. 5 is an illustration of a flat tube heat exchanger in
accordance with a second embodiment of the present invention in the
form of a helix;
[0014] FIG. 6 is an illustration of a flat tube heat exchanger in
accordance with a third embodiment of the present invention in a
layered form;
[0015] FIG. 7 is an illustration of a flat tube heat exchanger with
a fin set in accordance with a fourth embodiment of the present
invention;
[0016] FIG. 8 is an illustration of a flat tube heat exchanger with
a fin set in accordance with a fourth embodiment of the present
invention with offset tubes;
[0017] FIG. 9 is an enlarged view of a portion of the flat tube
heat exchanger of FIG. 8 illustrating the offset tubes; and
[0018] FIG. 10 is an illustration of a refrigerator with the flat
tube heat exchanger of FIG. 6 mounted therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The present invention is directed to a flat tube heat
exchanger useful in many different environments where heat transfer
is necessary, such as refrigeration systems, radiators, oil
coolers, air coolers, condensers, evaporators and heat sinks. For
example, while the drawing of the embodiment of the present
invention illustrates the use of an embodiment of the flat tube
heat exchanger in a refrigeration environment, the present
invention can be used in other types of heat transfer, such as air
to liquid, air to air, liquid to liquid, or liquid to air. The flat
tube heat exchanger of the present invention can take a wide
variety of shapes and sizes beyond the specific embodiment
illustrated in the present invention. Further, the heat transfer
may take place in either direction depending upon the
application.
[0020] A first embodiment of the flat tube heat exchanger 10 of the
present invention is illustrated in FIGS. 1-4. With reference to
FIG. 1, a bottom perspective view of a flat tube heat exchanger 10
connected to a plate 12 is illustrated. The plate 12 can act as a
shelf in a refrigerator or reach-in cooler for the storage of
food/beverage items. The flat tube heat exchanger 10 operates in a
conventional manner to cool the plate 12 with a suitable
refrigerant being passed through the flat tube heat exchanger 10.
The refrigerant in the flat tube heat exchanger 10 absorbs heat
from the plate 12 and causes the refrigerant to evaporate as it
passes through the flat tube heat exchanger 10. As a result, the
temperature of the plate 12 is reduced thereby keeping the items
placed on the top surface thereof at a reduced temperature.
[0021] The plate 12 includes a top surface (not shown), a bottom
surface 14, and sides 16. The flat tube heat exchanger tube 10 is
attached to the bottom of the plate 12 using conventional
attachment elements such as a very high bonding double sided tape,
an adhesive or other known conventional fastening mechanism.
[0022] The flat tube heat exchanger 10 is illustrated in a
serpentine embodiment as best illustrated in FIG. 3. Two opposing
connections 20, 22 provide an inlet and outlet for the refrigerant
material. As illustrated in FIG. 4, the flat tube heat exchanger 10
includes a first flat side 26 and an opposing second flat side 28.
The first flat side 26 and second flat side 28 are interconnected
by the opposing sides 30, 32. As shown in FIG. 4, the flat tube
heat exchanger 10 is longer on the first and second flat sides 26,
28 (the width) than on the opposing sides 30, 32 (the height). This
configuration increases the primary surface area relative to the
cross-sectional area of the tube, thereby providing improved heat
transfer. In addition, this configuration minimizes the profile of
the tube allowing it to be used in smaller areas. While it should
be recognized the opposing sides 30, 32 are rounded, they may also
take other shapes such as forming flat sides.
[0023] A series of internal partitions 40 are provided between the
first flat side 26 and the second flat side 28. The flow ducts 42
form a passageway for refrigerant or other heat transfer medium
through the flat tube heat exchanger 10. The present embodiment
illustrates the use of eleven flow ducts 42. However, it should be
recognized that the number of flow ducts may be selected to suit
the needs of a particular application. The internal partitions 40
provide additional strength to the flat tube heat exchanger 10 and
assist in the heat transfer function.
[0024] With reference to FIG. 3, the flat tube heat exchanger 10
includes eleven U-shaped return bends 50 that form the serpentine
shape. The bends 50 are formed in a plane defined by the first flat
side 26. The bends 50 are also formed around the height axis
defined by the opposing sides 30, 32. It should be recognized that
more than or fewer than eleven U-shaped return bends may be
implemented to suit the needs of a particular application. The
bends 50 can also be formed with an angle greater than or less than
180 degrees.
[0025] The flat tube heat exchanger 10 can be formed having a width
in the range of 0.375 to 3 inches and with a tube thickness in the
range of 0.062 to 0.5 inches. The wall thickness may depend on the
material used to form the tube and the particular application. The
flat tube heat exchanger 10 may be formed in a number of various
lengths and widths and out of a number of various known materials,
e.g., aluminum, as necessary to suit needs of the particular
application.
[0026] The flat tube heat exchanger 10 is formed using a
conventional serpentine type bender. The machine is equipped with
tooling to support and minimize deformation of the manufactured
tube bends, in order to retain it in a flat configuration. In
particular, the flat tube heat exchanger is formed by crushing the
tube into a radius formed block to maintain a consistent flow of
material throughout the bend. Crushing compression is applied by a
follow block formed to hold and shape the material flat and
parallel to the heat exchanger. The tube is fully enclosed by the
inside radius block and the follow-up block to maintain the overall
tube dimensions and shape. The flat tube heat exchanger 10 is
formed by bending the tube while simultaneously supporting the
sides and radii.
[0027] FIG. 5 is an illustration of a flat tube heat exchanger 120
in accordance with a second embodiment of the present invention.
The flat tube heat exchanger 120 is formed in the shape of a helix.
Return bends 121 are formed substantially in a plane defined by at
least one of the opposing flat sides 122, 124. The flat tube heat
exchanger 120 is formed in essentially the same manner as flat tube
heat exchanger 10 of FIGS. 1-4, with the exception that during the
formation process, all bends are formed in the same direction. In
addition, the flat tube heat exchanger 120 functions generally in
the same way as the flat tube heat exchanger 10 of FIGS. 1-4 with
the exception of the helix shape offering unique air flow
characteristics that may be useful in certain applications. The
flat tube heat exchanger 120 may be formed with a right hand or
left hand rotation. The cross section of the spiral may take forms
as known by those of ordinary skill in the art such as rectangular,
round, oval, or other known shapes. In addition, the density of the
helix shape may be altered to suit particular applications.
[0028] FIG. 6 is an illustration of a flat tube heat exchanger 150
in accordance with a third embodiment of the present invention. The
flat tube heat exchanger 150 is formed in the shape of a layered
symmetrical pattern. Return bends 151 are formed substantially in a
plane defined by the opposing flat sides 152, 154. The flat tube
heat exchanger 150 has a layered shape that is a combination of the
serpentine and helical shape to create a multi-plane serpentine.
The layers 160, 162, 164, 166, 168 may be formed in an aligned or
staggered configuration. The flat tube heat exchanger 150 is formed
in essentially the same manner as flat tube heat exchanger 10 of
FIGS. 1-4, with the exception that during the formation process
layers are introduced. In addition, the flat tube heat exchanger
150 functions generally in the same way as the flat tube heat
exchanger 10 of FIGS. 1-4, with the exception of the overlay shape
offering unique air flow characteristics that may be useful in
certain applications.
[0029] FIG. 7 is an illustration of a flat tube heat exchanger 200
with a fin set 202 in accordance with a fourth embodiment of the
present invention. The flat tube heat exchanger 200 is formed with
return bends 204 formed substantially in a plane defined by at
least one of the opposing flat sides 208, 210 or around the height
axis. Return bends 220 are formed in a plane defined by the
opposing sides 230, 232 or around the width axis. The flat tube
heat exchanger 200 is formed in essentially the same manner as the
flat tube heat exchanger 10 of FIGS. 1-4, with the exception that
during the formation process, existing technology of returns 220 is
used in combination with the new technology 204. In addition, the
fin set 202 is also attached thereto. In addition, the flat tube
heat exchanger 200 functions generally in the same way as the flat
tube heat exchanger 10 of FIGS. 1-4, with the exception of the
shape and fin set 202 offering unique air flow characteristics that
may be useful in certain applications. It should be recognized that
the present invention may be used with or without fins.
[0030] FIGS. 8-9 are an illustration of a flat tube heat exchanger
250 with a fin set 252 in accordance with a fifth embodiment of the
present invention. The flat tube heat exchanger 250 has essentially
the same configuration of FIG. 7, with the exception of having
offset return bends 254. The flat tube heat exchanger 250 is formed
in essentially the same manner as flat tube heat exchanger 200 of
FIG. 7, with the exception that during the formation process, a
secondary process is used to offset the tubes. In addition, the
flat tube heat exchanger 250 functions generally in the same way as
the flat tube heat exchanger 200 of FIG. 7, with the exception of
the shape and fin set 252 offering unique air flow characteristics
that may be useful in certain applications.
[0031] FIG. 10 is an illustration of refrigerator 300 with the flat
tube heat exchanger 150 of FIG. 6 mounted therein and with the rear
interior surface of the refrigerator removed. A door 302 and
shelves 304 are illustrated. The flat tube heat exchanger 150
operates as explained herein to provide improved efficiencies over
a conventional heat exchanger.
[0032] The embodiments described above and shown herein are
illustrative and not restrictive. The scope of the invention is
indicated by the claims rather than by the foregoing description
and attached drawings. The invention may be embodied in other
specific forms without departing from the spirit of the invention.
For example, the overall configuration of the flat tube heat
exchanger of the present invention may be designed and configured
in a manner other than as specifically illustrated in the figures.
In addition, the present invention may be used with or without
fins. Accordingly, these and any other changes which come within
the scope of the claims are intended to be embraced herein.
* * * * *