U.S. patent application number 11/848052 was filed with the patent office on 2009-03-05 for heat exchanger having an internal bypass.
Invention is credited to Catherine R. Braun.
Application Number | 20090056909 11/848052 |
Document ID | / |
Family ID | 40405589 |
Filed Date | 2009-03-05 |
United States Patent
Application |
20090056909 |
Kind Code |
A1 |
Braun; Catherine R. |
March 5, 2009 |
HEAT EXCHANGER HAVING AN INTERNAL BYPASS
Abstract
The present invention provides an exhaust recirculation cooler
for transferring heat between engine exhaust and a coolant. The
cooler can include a housing having a first end and a second end
spaced from the first end, a heat transfer region extending through
the housing and including a plurality of tubes positioned along a
flow path for the coolant, and an internal bypass extending through
the housing between the first end and the second end adjacent to
the heat transfer region. Together, at least one of the plurality
of tubes and the internal bypass provide an exhaust flow path
through the cooler.
Inventors: |
Braun; Catherine R.;
(Milwaukee, WI) |
Correspondence
Address: |
MICHAEL BEST & FRIEDRICH LLP
100 E WISCONSIN AVENUE, Suite 3300
MILWAUKEE
WI
53202
US
|
Family ID: |
40405589 |
Appl. No.: |
11/848052 |
Filed: |
August 30, 2007 |
Current U.S.
Class: |
165/54 ; 165/103;
165/283 |
Current CPC
Class: |
F02M 26/32 20160201;
F02M 26/25 20160201; F28F 27/02 20130101; F28D 7/1684 20130101;
F28F 2250/06 20130101 |
Class at
Publication: |
165/54 ; 165/103;
165/283 |
International
Class: |
F28F 27/02 20060101
F28F027/02; F28F 9/00 20060101 F28F009/00 |
Claims
1. An exhaust recirculation cooler for transferring heat between
engine exhaust and a coolant, the heat exchanger comprising: a
housing having a first end and a second end spaced from the first
end; a heat transfer region extending through the housing and
including a plurality of tubes positioned along a flow path for the
coolant; and an internal bypass extending through the housing
between the first end and the second end adjacent to the heat
transfer region, together, at least one of the plurality of tubes
and the internal bypass providing an exhaust flow path through the
cooler.
2. The exhaust recirculation cooler of claim 1, wherein the coolant
is directed across a wall of the bypass.
3. The exhaust recirculation cooler of claim 1, wherein the exhaust
flow path is a first exhaust flow path, and further comprising a
second exhaust flow path extending through an other of the
plurality of tubes, and a valve located adjacent to the second end
of the housing and being moveable relative to the housing to
selectively direct the exhaust through the first and second exhaust
flow paths.
4. The exhaust recirculation cooler of claim 1, further comprising
a header secured to an end of the plurality of tubes and defining
an inlet to the heat transfer region, an outlet to the heat
transfer region and one of an inlet and an outlet to the
bypass.
5. The exhaust recirculation cooler of claim 1, wherein the exhaust
flow path includes two passes extending through the housing between
the first and second ends in counter flow directions.
6. The exhaust recirculation cooler of claim 1, wherein the exhaust
flow path is a first exhaust flow path, and further comprising a
second exhaust flow path extending through an other of the
plurality of tubes, and a valve located adjacent to an outlet of
the bypass and being moveable relative to the housing to
selectively direct the exhaust from the first exhaust flow path
through the second exhaust flow path and away from the cooler.
7. An exhaust recirculation cooler comprising: a housing having a
first end and a second end spaced from the first end and at least
partially enclosing a heat transfer region; a primary exhaust flow
path including two passes extending through the housing between the
first and second ends in counter flow directions, at least a
portion of the primary exhaust flow path having heat-transfer
augmentations and extending through the heat transfer region
wherein heat is transferred from exhaust traveling through the
primary exhaust flow path to a coolant flow path; and a secondary
exhaust flow path extending through the housing between the first
end and the second end and being substantially free from heat
transfer augmentations.
8. The exhaust recirculation cooler of claim 7, wherein the heat
transfer region includes a plurality of tubes, and further
comprising an internal bypass extending through the housing between
the first end and the second end adjacent to the heat transfer
region.
9. The exhaust recirculation cooler of claim 8, wherein the primary
exhaust flow path extends through at least one of the plurality of
tubes.
10. The exhaust recirculation cooler of claim 8, wherein the
coolant flow path is directed across a wall of the bypass.
11. The heat exhaust recirculation cooler of claim 7, further
comprising a heat exchanger core including a plurality of tubes
supported in the housing and extending through the heat transfer
region, the primary exhaust flow path extending through at least
one of the plurality of tubes, and wherein the secondary exhaust
flow path extends through an other of the plurality of tubes.
12. The heat exhaust recirculation cooler of claim 7, further
comprising a header supported at one end of the housing and at
least partially defining an inlet to each of the primary and
secondary exhaust flow paths.
13. The exhaust recirculation cooler of claim 7, further comprising
a valve located adjacent to the second end of the housing and being
moveable relative to the housing to selectively direct the exhaust
through the primary and secondary exhaust flow paths.
14. The exhaust recirculation cooler of claim 7, further comprising
a header secured to one of the first end and the second end of the
housing and defining an inlet to the primary exhaust flow path, an
outlet to the primary exhaust flow path, and one of an inlet and an
outlet to the secondary exhaust flow path.
15. A method of operating an exhaust recirculation cooler including
a housing at least partially defining a heat transfer region, the
method comprising the act of: directing engine exhaust through the
housing between first and second ends of the housing around the
heat transfer region and back through the heat transfer region.
16. The method of claim 15, further comprising moving a valve
relative to the housing to adjust the exhaust flow through the
housing.
17. The method of claim 16, wherein moving the valve includes
moving the valve from a first position, in which the valve directs
the engine exhaust from a bypass extending through the housing
between the second end and the first end into the heat transfer
region, and a second position, in which the valve directs the
engine exhaust from the bypass away from the heat transfer
region.
18. The method of claim 15, wherein the heat exchanger includes a
header supported in the housing, and wherein directing the engine
exhaust through the housing includes directing the exhaust through
an inlet of an exhaust flow path defined in the header and
directing the engine exhaust through an outlet of the exhaust flow
path defined in the header.
19. The method of claim 15, wherein directing the engine exhaust
around the heat transfer region includes directing the exhaust
through an internal bypass extending through the housing.
20. The method of claim 19, wherein the heat exchanger includes a
header supported in the housing, and wherein directing the engine
exhaust through the internal bypass includes directing the engine
exhaust through an outlet of the internal bypass defined in the
header and through an inlet of an exhaust flow path defined in the
header.
21. The method of claim 15, wherein directing the engine exhaust
through the housing includes directing the engine through two
passes extending through the housing between the first and second
ends in counter flow directions.
22. A method of operating an exhaust recirculation cooler including
a housing having a first end and a second end and at least
partially defining a heat transfer region, the method comprising
the acts of: directing engine exhaust along two passes through the
heat transfer region in counter flow directions; transferring heat
from the engine exhaust traveling through the heat transfer region
to coolant traveling through the heat transfer region; and
directing engine exhaust from the first end of the housing toward
the second end of the housing through an internal bypass in the
housing and around the heat transfer region.
23. The method of claim 22, further comprising moving a valve
relative to the housing to adjust the flow of engine exhaust
through the housing.
24. The method of claim 23, wherein moving the valve includes
moving the valve from a first position, in which the valve directs
the engine exhaust from the bypass into the heat transfer region,
and a second position, in which the valve directs the engine
exhaust from the bypass away from the heat transfer region.
25. The method of claim 24, wherein the heat exchanger includes a
header supported in the housing, and wherein directing the engine
exhaust through the internal bypass includes directing the engine
exhaust through an outlet of the internal bypass defined in the
header and through an inlet of an exhaust flow path defined in the
header.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to heat exchangers and, more
particularly, to an exhaust gas waste heat recovery system and a
method of operating the same.
SUMMARY
[0002] In some embodiments, the present invention provides an
exhaust recirculation cooler for transferring heat between engine
exhaust and a coolant. The cooler can include a housing having a
first end and a second end spaced from the first end, a heat
transfer region extending through the housing and including a
plurality of tubes positioned along a flow path for the coolant,
and an internal bypass extending through the housing between the
first end and the second end adjacent to the heat transfer region.
Together, at least one of the plurality of tubes and the internal
bypass can provide an exhaust flow path through the cooler.
[0003] The present invention also provides an exhaust recirculation
cooler including a housing having a first end and a second end
spaced from the first end and at least partially enclosing a heat
transfer region, and a primary exhaust flow path including two
passes extending through the housing between the first and second
ends in counter flow directions. At least a portion of the primary
exhaust flow path can have heat-transfer augmentations and can
extend through the heat transfer region wherein heat is transferred
from exhaust traveling through the primary exhaust flow path to a
coolant flow path. The cooler can also include a secondary exhaust
flow path extending through the housing between the first end and
the second end and being substantially free from heat transfer
augmentations.
[0004] In addition, the present invention provides a method of
operating an exhaust recirculation cooler including a housing at
least partially defining a heat transfer region. The method can
include the act of directing engine exhaust through the housing
between first and second ends of the housing around the heat
transfer region and back through the heat transfer region.
[0005] The present invention also provides a method of operating an
exhaust recirculation cooler including a housing having a first end
and a second end and at least partially defining a heat transfer
region. The method can include the acts of directing engine exhaust
along two passes through the heat transfer region in counter flow
directions, transferring heat from the engine exhaust traveling
through the heat transfer region to coolant traveling through the
heat transfer region, and directing engine exhaust from the first
end of the housing toward the second end of the housing through an
internal bypass in the housing and around the heat transfer
region.
[0006] Other aspects of the invention will become apparent by
consideration of the detailed description and accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of a heat exchanger according
to some embodiments of the present invention.
[0008] FIG. 2 is another perspective view of the heat exchanger
shown in FIG. 1 with a collection tank removed.
[0009] FIG. 3 is an exploded perspective view of the heat exchanger
shown in FIG. 1.
[0010] FIG. 4 is an end view of the heat exchanger shown in FIG. 1
with a collection tank removed.
[0011] FIG. 5 is a cross-sectional view of the heat exchanger shown
in FIG. 1.
[0012] FIG. 6 is another cross-sectional view of the heat exchanger
shown in FIG. 1.
[0013] FIG. 7 is yet another cross-sectional view of the heat
exchanger shown in FIG. 1.
[0014] FIG. 8 is a perspective end view of the heat exchanger shown
in FIG. 1 with a valve in a second position.
[0015] FIG. 9 is a perspective end view of the heat exchanger shown
in FIG. 1 with the valve in a first position.
[0016] FIG. 10 is an end view of a portion of a heat exchanger
according to an alternative embodiment of the present
invention.
[0017] FIG. 11 is an exploded perspective view of the heat
exchanger shown in FIG. 10.
[0018] FIG. 12 is a cross-sectional view of the heat exchanger
shown in FIG. 10.
[0019] FIG. 13 is another cross-sectional view of the heat
exchanger shown in FIG. 10.
[0020] FIG. 14 is yet another cross-sectional view of the heat
exchanger shown in FIG. 10.
DETAILED DESCRIPTION
[0021] Before any embodiments of the invention are explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangement
of components set forth in the following description or illustrated
in the following drawings. The invention is capable of other
embodiments and of being practiced or of being carried out in
various ways. Also, it is to be understood that the phraseology and
terminology used herein is for the purpose of description and
should not be regarded as limiting. The use of "including,"
"comprising," or "having" and variations thereof herein is meant to
encompass the items listed thereafter and equivalents thereof as
well as additional items.
[0022] Unless specified or limited otherwise, the terms "mounted,"
"connected," "supported," and "coupled" and variations thereof are
used broadly and encompass both direct and indirect mountings,
connections, supports, and couplings. Further, "connected" and
"coupled" are not restricted to physical or mechanical connections
or couplings.
[0023] Also, it is to be understood that phraseology and
terminology used herein with reference to device or element
orientation (such as, for example, terms like "central," "upper,"
"lower," "front," "rear," and the like) are only used to simplify
description of the present invention, and do not alone indicate or
imply that the device or element referred to must have a particular
orientation. In addition, terms such as "first," "second," and
"third" are used herein for purposes of description and are not
intended to indicate or imply relative importance or
significance.
[0024] FIGS. 1-9 illustrate a heat exchanger 10 according to some
embodiments of the present invention. In some embodiments,
including the illustrated embodiment of FIGS. 1-9, the heat
exchanger 10 can operate as an exhaust gas recirculation cooler
(EGRC) and can be operated with the exhaust system of a vehicle. In
other embodiments, the heat exchanger 10 can be used in other
(e.g., non-vehicular) applications, such as, for example, in
electronics cooling, industrial equipment, building heating and
air-conditioning, and the like. In addition, it should be
appreciated that the heat exchanger 10 of the present invention can
take many forms, utilize a wide range of materials, and can be
incorporated into various other systems.
[0025] As shown in FIGS. 1-3 and 5-9, the heat exchanger 10 can
include a housing 12 having a first end 14 and a second end 16. The
housing 12 can also include an inlet 20 for receiving a first
working fluid (e.g., water, engine coolant, CO.sub.2, an organic
refrigerant, R12, R245fa, air, and the like) and an outlet 22 for
dispensing the first working fluid. In the illustrated embodiment
of FIGS. 1-9, the inlet 20 can be positioned adjacent to the second
end 16 of the housing 12 and the outlet 22 can be positioned
adjacent to the first end 14 of the housing 12 such that the first
working fluid travels along a flow path (represented by arrows 24
in FIGS. 1-7) through the length of the housing 12 between the
first and second ends 14, 16 or through substantially the entire
length of the housing 12. In other embodiments the inlet 20 and
outlet 22 can have other locations along the housing 12 and the
flow path 24 of the first working fluid can extend through other
portions of the housing 12, or alternatively, through the housing
12 in a different manner.
[0026] In some embodiments such as the illustrated embodiment of
FIGS. 1-9, the heat exchanger 10 can include a first collection
tank 28 secured to the first end 14 of the housing 12 and a second
collection tank 30 secured to the second end 16 of the housing 12.
As shown in FIG. 3, the first collection tank 20 can include an
inlet opening 32 and the second collection tank 30 can include
first and second outlet openings 34, 36.
[0027] The heat exchanger 10 can also or alternatively include a
first header 40 positioned between the first end 14 of the housing
12 and the first collection tank 28 and a second header 42
positioned between the second end 16 of the housing 12 and the
second collection tank 30. In some such embodiments, the first
header 40 can at least partially enclose a fluid reservoir of the
first collection tank 28 and the second header 42 can at least
partially enclose a fluid reservoir of the second collection tank
30. In other embodiments, the heat exchanger 10 can include a
single header 40 and/or a single collection tank 28 located at one
of the first and second ends 14, 16 or at another location on the
heat exchanger 10.
[0028] In some embodiments, the first and second headers 40, 42 can
be substantially similarly configured and can be substantially
similarly sized. For example, in the illustrated embodiment of
FIGS. 1-9, the first and second headers 40, 42 are substantially
interchangeable. In other embodiments, the first and second headers
40, 42 can be differently sized and/or differently configured.
[0029] As shown in FIGS. 2-9, the heat exchanger 10 can also
include a heat exchanger core 52 including a stack of tubes 56. In
the illustrated embodiment, the heat exchanger core 52 includes two
rows of seven tubes 56. In other embodiments, the heat exchanger
core 52 can include two, three, four, five, six, or more tubes 56
arranged in one, two, three, or more adjacent rows. In still other
embodiments, the heat exchanger core 52 can include a bundle of
tubes 56, or alternatively, a ring or spiral arrangement of
substantially parallel tubes 56. As shown in FIGS. 2-9, opposite
ends of the tubes 56 are secured to the first and second headers
40, 42.
[0030] The heat exchanger core 54 can also include a number of
baffles 58 (e.g., six in the illustrated embodiment of FIGS. 1-9)
spaced between the first and second ends 44, 46 of the housing 12
for supporting the tubes 56 and for maintaining a desired spacing
between each of the tubes 56. The baffles 58 can also or
alternatively define or partially define the flow path 24 of the
first working fluid. For example, in the illustrated embodiment of
FIGS. 5-7, the flow path 24 of the first working fluid can extend
between the inlet and outlet 20, 22 and between the baffles 58 such
that the flow path 24 for the first working fluid follows a
serpentine path through the heat exchanger core 54 and such that
the first working fluid travels across and between the exterior
surfaces of all or substantially all of the tubes 56 of the heat
exchanger core 54. The flow path 24 for the first working fluid can
also or alternatively extend across and between the exterior
surfaces of the tubes 56 of the internal bypass 66 so that all or
substantially all of the tubes 56 of the heat exchanger core 54
experience the same or similar temperature fluctuations and so that
the thermal expansion of each of the tubes 56 is substantially the
same as the adjacent tubes 56.
[0031] As shown in FIGS. 2 and 4-9, the heat exchanger core 54 can
also or alternatively include a heat transfer region 60. The heat
transfer region 60 can include one or more of the tubes 56, and
each of the tubes 56 in the heat transfer region 60 can include
surface augmentations 62 for increasing heat transfer between the
first working fluid traveling along the first flow path 24 and a
second working fluid (e.g., exhaust gas, water, engine coolant,
CO.sub.2, an organic refrigerant, R12, R245fa, air, and the like)
traveling along a second flow path (represented by arrows 64 in
FIGS. 5-7). In the illustrated embodiment of FIGS. 2 and 4-9, the
surface augmentations 62 are corrugated fins extending through the
interior of each of the tubes 56 of the heat transfer region 60. In
other embodiments, the tubes 56 of the heat transfer region 60 can
also or alternatively include other surface augmentations, such as
for example, protrusions, recesses, tubulators, etc. located along
interior and/or exterior surfaces of the tubes 56 of the heat
transfer region 60.
[0032] In some embodiments, such as the illustrated embodiments of
FIGS. 1-9, the heat exchanger core 54 can also include an internal
bypass 66 extending through at least one of the tubes 56 (e.g.,
three tubes 56 in the embodiment of FIGS. 1-9) and extending
through the housing 12 between the first and second headers 40, 42
adjacent to the heat transfer region 60. As shown in FIGS. 2-6, the
tubes 56 of the bypass 66 are substantially smooth and are free
from heat transfer augmentations and provide a passthrough for the
second working fluid such that the second working fluid can bypass
the heat transfer region 60.
[0033] The tube or tubes 56 of the bypass 66 can also or
alternatively be positioned along the flow path 24 of the first
working fluid. In some embodiments, the tube or tubes 56 of the
bypass 66 can be at least partially insulated and/or can have a
thicker outer wall than the tube or tubes 56 of the heat exchange
region 60 to prevent and/or reduce the transfer of heat between the
first working fluid traveling along the first flow path 24 and the
second working fluid traveling through the bypass 66 along the
second flow path 64. Alternatively or in addition, the bypass 66
can be configured such that the second working fluid travels at a
greater velocity through the tube or tubes 56 of the bypass 66 than
the tubes 56 of the heat transfer region 60. For example, as shown
in FIGS. 1-9, the bypass 66 includes three tubes 56 and the first
pass through the heat transfer region 60 includes seven
substantially similarly sized tubes 56. In this manner, while heat
transfer can occur between the second working fluid traveling
through the tubes 56 of the bypass 66 and the first working fluid
traveling across the tubes 56 of the bypass 66, significantly more
heat transfer can occur between the second working fluid traveling
through the heat transfer region 60 and the first working fluid
traveling across the tubes 56 of the heat transfer region 60.
[0034] The heat exchanger 10 can also include a valve 70 supported
adjacent to a flow-directing wall 74 downstream from the second
header 42 for controlling the flow of the second working fluid. In
some embodiments such as the illustrated embodiment of FIGS. 1-9,
the valve 70 can be supported in the second collection tank 30
along the flow path 64 for the second working fluid and can be
moveable between a first position (shown in FIG. 9), in which the
valve 70 directs the second working fluid from the bypass 66 along
a first or primary pathway 64A of the second flow path 64 into the
heat transfer region 60, and a second position (shown in FIG. 8),
in which the valve 70 directs the second working fluid out of the
second collection tank 30 and away from the heat exchanger 10 along
a second or secondary pathway 64B of the second flow path 64.
[0035] During operation, the heat exchanger 10 can transfer heat
from the second working fluid to the first working fluid.
Alternatively, while reference is made herein to transferring heat
between two working fluids, in some embodiments of the present
invention, the heat exchanger 10 can operate to transfer heat
between three or more fluids. In other embodiments, the heat
exchanger 10 can operate as a recuperator and can transfer heat
from a high temperature location of a heating circuit to a low
temperature location of the same heating circuit. In some such
embodiments, the heat exchanger 10 can transfer heat from a working
fluid traveling through a first portion of the heat transfer
circuit to the same working fluid traveling through a second
portion of the heat transfer circuit.
[0036] With reference to FIG. 5, during normal operation, the
second working fluid traveling along the second flow path 64 enters
the first collection tank 28 through the inlet opening 32, travels
through the first header 40, and through the bypass 66 around the
heat transfer region 60 before entering the second collection tank
30 through the second header 42. In this manner, the second working
fluid can travel in a first pass through the heat exchanger core 52
along the second flow path 64.
[0037] Once the second working fluid is downstream from the second
header 42 and/or once the second working fluid enters the second
collection tank 30, the valve 70 selectively directs the second
working fluid into the heat transfer region 60 or away from the
heat exchanger 10. More specifically, when the valve 70 is moved
toward the second position (shown in FIG. 8), the valve 70 and the
wall 74 prevent the second working fluid from entering the heat
transfer region 60 through the second header 42 and direct the
second working fluid outwardly through the first outlet opening 34
in the second collection tank 30 and along the secondary pathway
64B.
[0038] When the valve 70 is moved toward the first position (shown
in FIG. 9), the valve 70 and the wall 74 prevent the second working
fluid from exiting the heat exchanger 10 by sealing the first
outlet opening 34 in the second collection tank 30 and direct the
second working fluid back through the second header 42 and into the
heat transfer region 60 along the primary pathway 64A. As shown in
FIG. 6, the second working fluid then travels along a second pass
through the heat exchanger core 52 along the flow path 64 before
passing through the first header 40 and entering the first
collection tank 28.
[0039] With reference to FIG. 7, from the first collection tank 28,
the second working fluid travels around a flow-directing wall 76
before passing back through the first header 40, reentering the
heat transfer region 60, and traveling along a third pass through
the heat exchanger core 52. As the second working fluid travels
along both passes of the flow path 64 through the heat transfer
region 60, heat is transferred from the second working fluid to the
first working fluid traveling along the flow path 24 through the
housing 12. The cooled second working fluid then continues along
the second flow path 64 through the second header 42 and out of the
second collection tank 30 through the second outlet opening 36.
[0040] In the illustrated embodiment of FIGS. 1-9, the heat
transfer region 60 has a U-shape such that the second working fluid
travels through the heat exchange region 60 along two substantially
parallel counter-flow passes (i.e., through a first pass between
the second header 42 and the first header 40 and back through a
second pass between the first header 40 and the second header 42).
In addition, the heat exchange core 52 of the illustrated
embodiment of FIGS. 1-9 is configured such that the second working
fluid traveling along the flow path 64 travels through the heat
exchanger core 52 along a first pass (i.e., through the bypass 66)
before traveling along the two additional passes (i.e., through the
two passes of the heat exchange region 60) of the heat exchange
core 52. In other embodiments, the heat transfer region 60 and the
heat exchange core 52 can have other shapes and configurations.
[0041] FIGS. 10-14 illustrate an alternate embodiment of a heat
exchanger 110 according to the present invention. The heat
exchanger 110 shown in FIGS. 10-14 is similar in many ways to the
illustrated embodiments of FIGS. 1-9 described above. Accordingly,
with the exception of mutually inconsistent features and elements
between the embodiment of FIGS. 10-14 and the embodiments of FIGS.
1-9, reference is hereby made to the description above accompanying
the embodiments of FIGS. 1-9 for a more complete description of the
features and elements (and the alternatives to the features and
elements) of the embodiment of FIGS. 10-14. Features and elements
in the embodiment of FIGS. 10-14 corresponding to features and
elements in the embodiments of FIGS. 1-9 are numbered in the 100
series.
[0042] In the illustrated embodiment of FIGS. 10-14, the heat
exchanger 110 includes an inlet 120 positioned adjacent to the
second end 116 of the housing 112 for receiving a first working
fluid and an outlet 122 positioned adjacent to the first end 114 of
the housing 112 for dispensing the first working fluid. During
operation, the first working fluid travels along a flow path
(represented by arrows 124 in FIGS. 11-14) through the length of
the housing 112 between the first and second ends 114, 116 and
between the baffles 158.
[0043] As shown in FIGS. 10-14, the heat exchanger 110 can include
a collection tank 128 secured to the first end 114 of the housing
112 and a mounting flange 143 secured to the second end 116 of the
housing 112. The heat exchanger 110 can also or alternatively
include a first header 140 positioned between the first end 114 of
the housing 112 and the collection tank 128 and a second header 142
positioned between the second end 116 of the housing 112 and the
mounting flange 143. As shown in FIGS. 10-14, the mounting flange
143 can define first, second, and third openings 144, 146, 148.
[0044] While reference is made herein to an embodiment in which a
collection tank 128 is secured to one end (i.e., the first end 114)
of the housing 112 and a mounting flange 143 is secured to an
opposite end (i.e., the second end 116) of the housing 112, in
other embodiments, mounting flanges 143 can be secured to both the
first and second ends 114, 116 of the housing 112, or
alternatively, a collection tank 128 can be secured to the second
end 116 of the housing 112 and a mounting flange 143 can be secured
to the first end 114 of the housing 112. As shown in FIGS. 10 and
12-14, a valve 170 can be supported adjacent to a flow-directing
wall 174 downstream from the mounting flange 143 for controlling
the flow of the second working fluid.
[0045] With reference to FIG. 12, during normal operation, the
second working fluid traveling along the second flow path 164
enters the collection tank 128 through the inlet opening 132, and
travels through the first header 140 and through the bypass 166
around the heat transfer region 160 before passing through the
first opening 144 in the mounting flange 143. In this manner, the
second working fluid can travel in a first pass through the heat
exchanger core 152 along the second flow path 164.
[0046] Once the second working fluid is downstream from the second
header 142 and/or the mounting flange 143, the valve 170
selectively directs the second working fluid into the heat transfer
region 160 or away from the heat exchanger 110. More specifically,
when the valve 170 is moved toward a second position, the valve 170
and the wall 174 prevent the second working fluid from entering the
heat transfer region 160 through the second opening 146 in the
mounting flange 143 and direct the second working fluid outwardly
away from the heat exchanger 110 and along the secondary pathway
(not shown).
[0047] When the valve 170 is moved toward the first position, the
valve 170 and the wall 174 prevent the second working fluid from
exiting the heat exchanger 110 and direct the second working fluid
toward the second opening 146 in the mounting flange 143 and into
the heat transfer region 160 along the primary pathway 164A. As
shown in FIG. 13, the second working fluid then travels along a
second pass through the heat exchanger core 152 along the flow path
164 before entering the collection tank 128.
[0048] With reference to FIGS. 13 and 14, from the collection tank
128, the second working fluid travels around a flow-directing wall
176 before reentering the heat transfer region 160 and traveling
along a third pass through the heat exchanger core 152. As the
second working fluid travels through both passes along the flow
path 164 through the heat transfer region 160, heat is transferred
from the second working fluid to the first working fluid traveling
through the housing 112 along the first flow path 124. The second
working fluid then continues along the second flow path 164 through
the third opening 148 in the second header 142 and away from the
heat exchanger 110.
[0049] The embodiments described above and illustrated in the
figures are presented by way of example only and are not intended
as a limitation upon the concepts and principles of the present
invention. As such, it will be appreciated by one having ordinary
skill in the art that various changes are possible.
* * * * *