Note: Descriptions are shown in the official language in which they were submitted.
CA 02520238 2005-09-19
Flanged Connection for Heat Exchanger
Field of the Invention
[0001] The present invention relates to a connection for an inlet or outlet of
a
heat exchanger, and more particularly to a flanged connection for an inlet or
outlet
of a heat exchanger.
Background of the Invention
[0002] Low profile heat exchangers typically use inlet and outlet fittings
that
are attached to openings in the top plate of the heat exchanger. The inlet and
outlet fittings are often elbow-type fittings: A disadvantage with this type
of fitting
is that it creates a pressure drop thereby reducing heat exchanger
performance.
Another disadvantage is that the fittings are often machined from aluminum.
This
type of fitting is costly to manufacture and must be secured to the heat
exchanger,
for example using brazing, which introduces an additional manufacturing step
thereby increasing the cost and complexity of manufacturing the heat
exchanger.
[0003] Stacked plate type heat exchangers are comprised of a number of
plates forming integral header tanks. This type of heat exchanger typically
uses
inlet and outlet fittings that are attached to one end of each tank. In
conventional
designs, the location of inlet and outlet fittings may impose restrictions on
the use
and design of this type of heat exchanger. Further, the installation of inlet
and
outlet fittings may require additional manufacturing steps that may be costly
and
time consuming.
[0004] Accordingly, there is a need for an inlet or outlet connection for a
heat
exchanger which is robust, efficient and economic to manufacture.
Summary
[0005] The present invention provides a flanged connection for an inlet or
outlet of a heat exchanger, for example a low profile heat exchanger or
stacked
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plate type heat exchanger. According to one example of the present invention,
there is provided a heat exchanger having a plate pair including first and
second
plates each having an outward depression extending to a peripheral edge
thereof,
the first and second plates defining a fluid channel therebetween and secured
to
one another with the outward depressions defining a flow opening in
communication with the fluid channel. The first plate includes an integral
semi-
annular first plate flange portion formed about a periphery of the first plate
outward
depression at a peripheral edge of the first plate and the second plate
includes an
integral semi-annular second plate flange portion formed about a periphery of
the
second plate outward depression at a peripheral edge of the second plate, the
semi-annular first and second plate flange portions collectively providing an
outer
flange extending substantially around a periphery of the flow opening. The
heat
exchanger includes a tubular fitting with a first end and an outer surface
having an
annular flange thereon spaced apart from the first end, the tubular fitting
being
secured to the plate pair with the first end received within the flow opening
and the
annular flange abutting against the outer flange.
[0006] According to another example embodiment, there is provided a heat
exchanger with a pair of substantially planar first and second plates each
having a
peripheral edge portion surrounding a central portion, the plates being
sealably
joined about the peripheral edge portions thereof and defining a fluid channel
between the central portions thereof, the first and second plates each
including an
outward depression extending to an edge thereof, the outward depressions
cooperating to form a flow opening communicating with the fluid channel and
extending through the peripheral edge portions of the first and second plates.
The
first plate includes a semi-annular first plate flange portion formed about a
periphery of the first plate outward depression at the peripheral edge portion
of the
first plate and the second plate including a semi-annular second plate flange
portion
formed about a periphery of the second plate outward depression at the
peripheral
edge portion of the second plate, the first plate flange portion and second
plate
flange portion jointly forming an outer flange extending substantially around
a
periphery of the flow opening, the outer flange having a substantially planar
surface
facing away from the flow opening. The heat exchanger also includes a tubular
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fitting having a body portion with a first end and an annular flange on an
outer
surface of the body portion spaced apart from the first end, the tubular
fitting being
secured to the plate pair with the first end received within the flow opening
and the
annular flange abutting against the substantially planar surface of the outer
flange.
[0007] According to a further example, there is provided a method for forming
a heat exchanger, including: providing a pair of substantially planar plates;
forming
in each of the plates an outward depression extending to a peripheral edge
thereof
from a location spaced inward from the peripheral edge thereof; forming a semi-
annular flange portion on each of the plates about a periphery of the outward
depression at the peripheral edge of the plate; arranging the plates together
to
define a fluid channel therebetween with the outward depressions defining a
flow
opening in communication with the fluid channel and with the semi-annular
flange
portions collectively forming an outer flange substantially about a periphery
of the
flow opening; providing a tubular fitting with a first end and an outer
surface having
an annular flange thereon spaced apart from the first end , and inserting the
first
end within the flow opening until the annular flange abuts against the outer
flange;
and securing the plates and the tubular fitting together.
[0008] Other aspects and features of the present invention will become
apparent to those ordinarily skilled in the art upon review of the following
description of specific embodiments of the invention in conjunction with the
accompanying figures.
Brief Descriution of the Drawin4s
[0009] Reference will now be made to the accompanying drawings which
show, by way of example, embodiments of the present invention, and in which:
[0010] Figure 1 is a perspective view of one embodiment of a low profile heat
exchanger according to the present invention;
[0011] Figure 2 is a perspective exploded view of one embodiment of a flanged
connection according to the present invention;
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[0012] Figure 3 is a sectional exploded view showing the flanged connection of
Figure 2 and a tubular fitting for insertion therein;
[0013] Figure 4 is a sectional view showing the flanged connection of Figure 3
having the tubular fitting inserted therein;
[0014] Figure 5 is an end view of the flanged connection of Figure 3 taken in
the direction indicated by the arrow 5;
[0015] Figure 6 is an end view of the flanged connection of Figure 4 taken in
the direction indicated by the arrow 6 showing the tubular fitting secured to
the
flanged connection;
[0016] Figure 7 is an end view of one embodiment of a stacked plate heat
exchanger according to the present invention; and
[0017] Figure 8 is front view of the heat exchanger of Figure 7.
[0018] Similar references are used in different figures to denote similar
components.
Detailed Description of the Drawingis
[0019] Reference is first made to Figure 1, which shows an example of a low
profile heat exchanger 10 to which example embodiments may be applied. The
heat exchanger 10 includes a substantially planar first or upper plate 42 and
substantially planar second or lower plate 44 defining an internal fluid flow
channel
therebetween. In the shown embodiment, the fluid flow channel (illustrated by
dashed line 12 in Figure 1) is defined by cooperating serpentine grooves 22
formed
in the upper and lower plates 42 and 44. The fluid flow channel 12 extends
between
fluid flow openings 58, 60 that are located at a peripheral edge of the heat
exchanger 10 and which function as a fluid inlet and a fluid outlet to the
fluid flow
channel 12 for a heat exchanger fluid. Although shown as serpentine in the
Figures, the fluid flow channel 12 defined by the plates 42, 44 may take other
configurations - for example, among other things, the fluid flow channel could
be a
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rectangular chamber having internal flow circuiting baffles or turbulizing
structures.
Although not shown, in some embodiments an air side fin plate having a
plurality of
spaced apart fins may be attached to an external surface of the first and/or
second
plates 42, 44.
[0020] As shown in Figure 2 to 4, a tubular fitting 70 is secured to each of
the
flow openings 58, 60 to enable inlet and outlet tubing to be connected to the
heat
exchanger 10. The connection of the tubular fitting 70 to flow openings 58, 60
will
now be described in greater detail. As seen in Figures 1 to 4, the lower plate
44 is
formed with spaced apart bosses or outward depressions 50 located at an edge
thereof. The outward depressions 50 extend from opposite ends of groove 22 to
the
edge of the lower plate 44.The upper plate 42 is formed with corresponding
spaced
apart outward depressions 46 located at an edge thereof. The outward
depressions
46 extend from opposite ends of groove 22 to the edge of the upper plate 42.
The
upper and lower plates 42, 44 are secured to each other, typically along the
peripheral edges thereof. In embodiments such as that shown as Figure 1,
central
portions of the plates 42, 44 that border the grooves 22 are also secured
together.
The outward depressions 46 of the upper plate 42 are aligned with the outward
depressions 50 of the lower plate 44 such that when the plates are secured,
the
outward depressions 46 and 50 define the spaced apart fluid openings 58, 60,
which communicate with opposite ends of the flow channel 22. In example
embodiments, the contoured plates 42, 44 are formed though stamping or roll-
forming of braze-clad metal, however the plates could alternatively be formed
using
other methods and/or out of other materials, such as plastic or composite
materials.
[0021] In an example embodiment, flow openings 58, 60 have a substantially
circular cross-section at the edge of the heat exchanger 10, and as indicated
in
Figures 2-4, a circular outer flange 61 extends substantially about the
periphery of
each flow opening 58, 60, providing a substantially planar bonding surface
around
the periphery of each flow opening 58, 60. In the embodiment of Figures 2-4,
each
circular flange 61 is formed by half flange portions 62 and 66 (e.g. semi-
annular or
semi-circular flange portions) that are integrally formed with the first and
second
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plates 42, 44 at the edges thereof about the periphery of outward depressions
46,
50. When the upper and lower plates 42 and 44 are secured to each other, the
half
flange portions 62, 66 form annular flanges 61 extending around an edge of the
openings 58, 60. Although the flow openings 58 and 60 and annular flanges 61
are
shown as circular in the figures, such openings and the surrounding annular
flanges
may be non-circular in alternative configurations. For example, the flow
openings
58, 60 could be elliptical or oval, or have multiple sides such as hexagonal
or
pentagonal, for example, and the surrounding flanges 61 have a corresponding
configuration. Thus, the annular flange 61 is not restricted to a "circular"
configuration but can take other configurations as required to surround the
corresponding opening 58, 60. In the shown embodiment, the half flange
portions
62, 66 include trailing edges 69; however in other embodiments the trailing
edges
69 may not be present. The semi-annular flange portions 62 and 66 are, in some
example embodiments, formed from portions of the plates 42 and 44 that have
been bent outwards so that the flange portions 62 and 66 are substantially
perpendicular to the remainder of the plates 42, 44, respectively.
[0022] Tubular fittings 70 are partially received in and secured within the
openings 58, 60. Each tubular fitting 70 includes a body 72 having an outer
surface
74. A first annular ring or flange 76 extends around the outer surface 74. The
first
annular flange 76 is inset from a first end 82 of the tubular fitting 70 and
extends
radially outward therefrom. The body 72 includes an inner portion 83, adjacent
the
first end 82 and an outer portion 84. The inner portion 83 is disposed within
the
opening 58, 60, with the first annular flange 76 abutting against the outer
flange
61. The tubular fitting 70 may be brazed or otherwise secured such that a
sealed
connection between the first annular flange 76 and flange 61 is formed about
the
circumference of opening 58, 60.
[0023] As shown in Figure 5 and 6, the flange 61 provides a flat annulus 67
for securely mounting the tubular fittings 70. When a tubular fitting 70 is
received
in the openings 58, 60, its outer flange 76 abuts the flange 61 in the area
defined
by the flat annulus 67 and may, in some applications, allow a reduction in or
elimination of the problems associated with braze voids. In an example
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embodiment, the outer flange 61 has a larger outer diameter than fitting
flange 76
such that flange 61 extends further radially outward than flange 76. In other
example embodiments, flange 61 is less than or the same size as flange 76.
[0024] Referring again to Figure 3, a further annular flange 86 spaced apart
from first flange 76 is provided around the outer surface 74 of the body 72 in
the
outer portion 84 of the tubular fitting 70. The further flange 86 acts as a
barb or
nipple to allow hoses, tubing, or other flexible conduit, such as fuel or
coolant lines,
to be attached to the tubular fitting 70 for the delivery/removal of fluid
to/from the
heat exchanger 10. A hose (not shown) may be slipped over the flange 86 and
secured thereto using a hose clamp (not shown) or other suitable fastener.
[0025] In the shown embodiment, openings 58, 60 are generally circular and
the body 72 of the tubular fitting 70 is generally cylindrical. In some
embodiment,
the body 72 has an outer diameter substantially the same as the diameter of
the
openings 58, 60. The openings 58, 60 may in some embodiments be non-circular,
such as elliptical or oval or multi-sided for example, with the body 72 having
a
corresponding mating shape.
[0026] The outer portion 84 of the tubular fittings 70 may be implemented in
a variety of ways depending on the type of connections that are contemplated
for a
particular application. For example, in some embodiments rather than having a
flange 86 for connecting to a hose, the tubular fitting 70 may include an
internally
threaded surface adapted to receive an externally threaded connector, plug or
conduit. Thus, a threaded connector or plug with a temperature sensor or other
measuring device therein could be threaded into the fitting 70 for measurement
of
a desired characteristic of the fluid flowing within the heat exchanger. In
other
embodiments, the tubular fitting 70 may have an externally threaded portion to
receive an internally threaded connector, plug or conduit. In other
embodiments,
the outer portion 84 the tubular fitting 70 has a reduced diameter internal
cylindrical surface for receiving an insert with a friction fit.
Alternatively, outer
portion 84 may have a grove for a crimp connection. A quick connect
configuration
could also be provided on outer portion 84.
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[0027] In some embodiments, the upper and lower plates 42, 44 are secured
to each other using brazing, and the tubular fitting 70 is secured with its
flange 76
against the flange 61 using brazing. However, in other embodiments welding,
thermal adhesive or other suitable means may be used.
[0028] The flanged connection described above may be used to provide any
number of the inlets and/or outlets of a heat exchanger. Further, although the
inlet
and outlet connections in the shown embodiments are located on a common side
of
the heat exchanger 10, it will be appreciated that a different arrangement or
configuration of the inlet and outlet connections are possible, and that the
connections may be located on any edge of the heat exchanger 10. For example,
in
some embodiments the connections may be located on opposite sides of the heat
exchanger or on adjacent corners. In some embodiments, only one of the inlet
or
outlet fitting may use the presently described connection.
[0029] Although the flanged connection has been described above in
combination with a low profile heat exchanger formed from a single pair of
plates,
the flanged connection could also be applied to a stacked-plate type of heat
exchanger. For example, with references to Figures land 8, an example
embodiment of a multiple stacked plate heat exchanger 100 will be described.
The
heat exchanger 100 comprises a plurality of stacked heat exchanger plate pairs
102
each defining an internal flow channel and having raised or enlarged portions
at the
opposite ends thereof to form inlet and outlet header tanks 104, 106
respectively.
Each plate pair 102 is formed of a pair of facing dished plate members 105
fixed
along their peripheral edges and provided with enlarged portions 108, 110 at
the
opposite ends of the heat exchanger having openings (not shown) therein. The
enlarged portions 108, 110 combine to form the inlet and outlet header tanks
104,
106 respectively. The openings in the enlarged portions 108, 110 are axially
aligned to provide a vertical flow passage through the header tanks. The plate
pairs
102 may be spaced apart to form air side inter-plate passages 112 and fins 114
may be located in such passages.
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[0030] Included among the plate pairs 102 is a plate pair 120 (shown as the
top plate pair in the illustrated example) that includes upper and lower
plates 142
and 144 respectively. The upper plate 142 is formed with spaced apart
enlarged,
outward depressions 146, 148 located at an edge thereof. The lower plate 144
is
formed with corresponding spaced apart enlarged, outward depressions 150, 152
located at an edge thereof. The outward depressions 146, 148 of the upper
plate
142 are aligned with the outward depressions150, 152 of the lower plate 144
such
that when the plates 142, 144 are secured, the upper plate depressions 146 and
148 define with lower plate depressions 150 and 152, respectively, spaced
apart
fluid flow openings 154, 160 that communicate with an internal flow channel
through plate 120 and, respectively, with the header tanks 104, 106.
[0031] Half flange portions 162 and 164 (e.g. semi-circular flange members)
integrally formed with the upper plate 142 are provided around the edges of
outward depressions 146, 148 of the upper plate 142. Half flange portions 166
and
168 (e.g. semi-circular flange members) integrally formed with the lower plate
144
are provided around the edges of outward depressions 150, 152 of the lower
plate
144. When the upper and lower plates 142 and 144 are secured to each other,
the
half flange portions 162, 164, 166, 168 form annular flanges 161, 163
extending
around an edge of the openings 154, 160. Thus, the flow openings of plate pair
120
have a similar configuration to the flow openings of the plate pair of Figures
1-4.
Tubular fittings 70 are secured within the openings 154, 160 with fitting
annular
flange 76 in abutting relation against the flanges 161, 163 in the manner
described
above in respect of the plate pairs of Figures 1-4. In addition to being used
on the
top or bottom plate pair in a stacked plate pair, the flanged connection could
also
be applied to plate pairs within the stack, as illustrated by connections 170
in
Figures 7 and 8.
[0032] Heat exchangers require fluid inlets and outlets for allowing fluid to
enter and exit the internal fluid flow passage(s). Embodiments of the present
invention provide a connection and connector for heat exchanger inlets and
outlets
that may be used in many types of heat exchanger designs, including low
profile or
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single plate type heat exchangers and multiple plate or stacked plate type
heat
exchangers.
[0033] In some example embodiments, the integration of the inlet and outlet
fittings into the edge area of the plates of the heat exchanger, simplifies
the
manufacturing process end lowers cost. Further, the flange connections of the
present invention, depending on the particular embodiment and application, may
reduce fluid pressure drop and increase heat exchanger performance as a result
of
the eliminating of 90° bends or elbows at the inlet and outlets. The
provision of a
flat annulus around the inlet/outlet openings provide a securing surface for
the
inlet/outlet fittings.
[0034] The presently discussed embodiments are considered to be illustrative
and not restrictive, the scope of the invention being indicated by the
appended
claims rather than the foregoing description, and all changes which come
within the
meaning and range of equivalency of the claims are therefore intended to be
embraced therein.
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