U.S. patent application number 11/565382 was filed with the patent office on 2007-11-15 for compact high temperature heat exchanger, such as a recuperator.
This patent application is currently assigned to MODINE MANUFACTURING COMPANY. Invention is credited to Jeroen Valensa, Mark G. Voss.
Application Number | 20070261837 11/565382 |
Document ID | / |
Family ID | 38310095 |
Filed Date | 2007-11-15 |
United States Patent
Application |
20070261837 |
Kind Code |
A1 |
Valensa; Jeroen ; et
al. |
November 15, 2007 |
COMPACT HIGH TEMPERATURE HEAT EXCHANGER, SUCH AS A RECUPERATOR
Abstract
A heat exchanger for transferring heat energy between a first
working fluid and a second working fluid. The heat exchanger can
include a first sheet contoured to define a plurality of first fins
and having an upper end and a lower end, a second sheet contoured
to define a plurality of second fins and being positioned between
the upper end of the first sheet and the lower end of the first
sheet, and a housing formed from a third sheet and at least
partially enclosing the first sheet and the second sheet.
Inventors: |
Valensa; Jeroen; (Muskego,
WI) ; Voss; Mark G.; (Franksville, WI) |
Correspondence
Address: |
MICHAEL BEST & FRIEDRICH LLP
100 E WISCONSIN AVENUE
Suite 3300
MILWAUKEE
WI
53202
US
|
Assignee: |
MODINE MANUFACTURING
COMPANY
1500 DeKoven Avenue
Racine
WI
53403-2552
|
Family ID: |
38310095 |
Appl. No.: |
11/565382 |
Filed: |
November 30, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60741537 |
Dec 1, 2005 |
|
|
|
Current U.S.
Class: |
165/185 ;
29/890.039 |
Current CPC
Class: |
F28D 9/0025 20130101;
Y10T 29/49366 20150115; F28D 21/0003 20130101; F28F 2220/00
20130101; F28F 3/025 20130101 |
Class at
Publication: |
165/185 ;
029/890.039 |
International
Class: |
F28F 3/02 20060101
F28F003/02 |
Claims
1. A heat exchanger for transferring heat energy between a first
working fluid and a second working fluid, the heat exchanger
comprising: a pair of first fins formed from a single sheet and at
least partially defining a flow path for the first working fluid;
and a second fin positioned between the pair of first fins and at
least partially defining a flow path for the second working fluid,
the flow path of the first working fluid being separated from the
flow path of the second working fluid.
2. The heat exchanger of claim 1, wherein a flow direction of the
first working fluid through the heat exchanger is substantially
counter to a flow direction of the second working fluid.
3. The heat exchanger of claim 1, wherein the second fin is formed
from a corrugated sheet.
4. The heat exchanger of claim 3, wherein the pair of first fins
are corrugations formed along the sheet.
5. The heat exchanger of claim 1, wherein an end of the second fin
is secured to one of the pair of first fins and an other end of the
second fin is secured to an other of the pair of first fins.
6. The heat exchanger of claim 1, wherein a pair of second fins are
positioned along the flow path of the second working fluid, the
second fin being one of the pair of second fins.
7. The heat exchanger of claim 6, wherein the pair of second fins
are formed from a single sheet.
8. The heat exchanger of claim 7, wherein the pair of second fins
are corrugations formed along the sheet.
9. The heat exchanger of claim 7, wherein the pair of first fins
have an upper end and a lower end, and wherein the second sheet is
positioned between the upper end of the pair of fins and the lower
end of the pair of first fins.
10. The heat exchanger of claim 1, wherein the pair of first fins
are formed from a first corrugated sheet, wherein the second fin is
formed from a second corrugated sheet, and wherein a housing is
formed from a third sheet, the housing at least partially enclosing
the first sheet and the second sheet.
11. The heat exchanger of claim 10, wherein the first sheet and the
third sheet substantially enclose the flow path for the first
working fluid, and wherein the first sheet, the second sheet, and
the third sheet together at least partially enclose the flow path
for the second working fluid.
12. The heat exchanger of claim 10, wherein the second sheet is
nested in the first sheet between the pair of first fins.
13. A heat exchanger for transferring heat energy between a first
working fluid and a second working fluid, the heat exchanger
comprising: a first corrugated sheet having a pair of peaks and
separating a flow path for the first working fluid from a flow path
for the second working fluid; and a second corrugated sheet
positioned between the pair of peaks of the first corrugated
sheet.
14. The heat exchanger of claim 13, wherein a flow direction of the
first working fluid along the flow path is substantially counter to
a flow direction of the second working fluid along the flow
path.
15. The heat exchanger of claim 13, wherein the second sheet has a
pair of peaks, and wherein the pair of peaks of the second sheet
are secured to one of the pair of peaks of the first sheet.
16. The heat exchanger of claim 13, wherein a side of the second
sheet is secured to one of the pair of peaks of the first sheet and
an other side of the second sheet is secured to an other of the
pair of peaks of the first sheet.
17. The heat exchanger of claim 13, wherein the first sheet has a
lower end, wherein the pair of peaks of the first sheet provide an
upper end, and wherein the second sheet is positioned between the
upper end and the lower end of the first sheet.
18. The heat exchanger of claim 13, wherein a housing is formed
from a third sheet, the housing at least partially enclosing the
first sheet and the second sheet.
19. The heat exchanger of claim 18, wherein the first sheet and the
third sheet substantially enclose the flow path for the first
working fluid, and wherein the first sheet, the second sheet, and
the third sheet together at least partially enclose the flow path
for the second working fluid.
20. The heat exchanger of claim 13, wherein the second sheet is
nested in the first sheet between the pair of peaks of the first
sheet.
21. A method of assembling a heat exchanger, the method comprising
the acts of: corrugating a first sheet to define a pair of peaks
and to at least partially define a flow path for a first working
fluid and a flow path for a second working fluid; corrugating a
second sheet; and nesting the second sheet in the first sheet
between the pair of peaks and along the flow path for the second
working fluid.
22. The method of claim 21, wherein nesting the second sheet
between the pair of peaks includes securing an end of the second
sheet to one of the pair of the peaks of the first sheet and
securing an other end of the second sheet to an other of the pair
of peaks of the first sheet.
23. The method of claim 21, further comprising securing a third
sheet to the peaks of the first sheet to at least partially enclose
the first flow path.
24. The method of claim 23, wherein securing the third sheet to the
peaks of the first sheet includes at least partially enclosing the
second flow path between the peaks of the first sheet and the third
sheet.
25. The method of claim 21, wherein corrugating the first sheet
includes defining a second pair of peaks, and further comprising
corrugating a third sheet and nesting the third sheet in the first
sheet between the second pair of peaks.
26. The method of claim 21, wherein nesting the second sheet
between the pair of peaks includes positioning the second sheet
between an upper end of the first sheet and a lower end of the
first sheet.
27. A heat exchanger for transferring heat energy between a first
working fluid and a second working fluid, the heat exchanger
comprising: a first sheet contoured to define a plurality of first
fins and having an upper end and a lower end; a second sheet
contoured to define a plurality of second fins and being positioned
between the upper end of the first sheet and the lower end of the
first sheet; and a housing formed from a third sheet and at least
partially enclosing the first sheet and the second sheet.
28. The heat exchanger of claim 27, wherein the housing defines an
inlet and an outlet for a Mow path for the first working fluid and
defines an inlet and an outlet for a flow path for the second
working fluid.
29. The heat exchanger of claim 28, wherein the second sheet is
positioned along the flow path of the second working fluid.
30. The heat exchanger of claim 28, wherein a flow direction of the
first working fluid is substantially counter to a flow direction of
the second working fluid.
31. The heat exchanger of claim 27, wherein the second sheet is
nested in the first sheet between two of the plurality of first
fins.
32. The heat exchanger of claim 27, wherein the plurality of first
fins are corrugations formed along the first sheet.
33. The heat exchanger of claim 27, wherein a side of the first
sheet is secured to one of the plurality of first fins and an other
side of the second sheet is secured to an other of the plurality of
first fins.
34. The heat exchanger of claim 27, wherein the plurality of second
fins are corrugations formed along the second sheet.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 [U.S.C. .sctn. 119
to U.S. Provisional Patent Application No. 60/741,537, filed on
Dec. 1, 2005, the contents of which is fully incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to heat exchangers, and more
specifically to heat exchangers (e.g., recuperators, exhaust gas
waste heat recovery systems, and the like) that can be compact
and/or can operate at high temperatures.
SUMMARY
[0003] Compact recuperators can be used in a number of
applications, such as, for example, in microturbines and high
temperature fuel cells. In these and other applications, system
efficiency can be optimized by heating a low temperature incoming
air stream to a temperature closer to a desired process operating
temperature via the transfer of thermal energy from a high
temperature waste stream of exhaust gas or air. The recuperator can
be a heat exchanger which allows for the efficient transfer of heat
energy from the hot stream to the cold stream while maintaining
isolation of the two streams.
[0004] In operation, compact recuperatores can be exposed to
operating temperatures above 750.degree. C. at a hot end, and to
near-ambient temperatures (i.e., less than 100.degree. C.) at a
cold end. The combination of high temperatures and large
temperature gradients with thin section materials has led to the
use of materials that exhibit high-temperature strength and
corrosion resistance at elevated temperatures, such as high nickel
content alloys. Such materials are relatively expensive, which
increases the demand for recuperator designs that minimize the
amount of material required to attain the desired heat transfer
capability. At the same time, the recuperator designs often
minimize the thermal stress induced by temperature gradients
throughout the device.
[0005] In some embodiments, the invention provides a heat exchanger
for transferring heat energy between a first working fluid and a
second working fluid. The heat exchanger can include a pair of
first fins formed from a single sheet and at least partially
defining a flow path for the first working fluid and a second fin
positioned between the pair of first fins and at least partially
defining a flow path for the second working fluid. The flow path of
the first working fluid can be separated from the flow path of the
second working fluid.
[0006] In other embodiments, the present invention provides a heat
exchanger including a first corrugated sheet having a pair of peaks
and separating a flow path for the first working fluid from a flow
path for the second working fluid, and a second corrugated sheet
positioned between the pair of peaks of the first corrugated
sheet.
[0007] In still other embodiments, the invention provides a heat
exchanger including a first sheet contoured to define a plurality
of first fins and having an upper end and a lower end, a second
sheet contoured to define a plurality of second fins and being
positioned between the upper end of the first sheet and the lower
end of the first sheet, and a housing formed from a third sheet and
at least partially enclosing the first sheet and the second
sheet.
[0008] The present invention also provides a method of assembling a
heat exchanger, including the acts of corrugating a first sheet to
define a pair of peaks and to at least partially define a flow path
for a first working fluid and a flow path for a second working
fluid, corrugating a second sheet, and nesting the second sheet in
the first sheet between the pair of peaks and along the flow path
for the second working fluid.
[0009] Other aspects of the invention will become apparent by
consideration of the detailed description and accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a partially exploded, perspective view of a
portion of a heat exchanger according to some embodiments of the
present invention;
[0011] FIG. 2 is a partially broken, perspective view of the heat
exchanger shown in FIG. 1;
[0012] FIG. 3 is a partially exploded, perspective view of the heat
exchanger shown in FIGS. 1 and 2 and including a housing;
[0013] FIG. 4 is a perspective view of the heat exchanger shown in
FIGS. 1-3; and
[0014] FIG. 5 is an end view of the heat exchanger shown in FIGS.
1-4.
DETAILED DESCRIPTION
[0015] 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," and "having" and variations thereof herein is meant
to encompass the items listed thereafter and equivalents thereof as
well as additional items.
[0016] 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.
[0017] 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.
[0018] FIGS. 1-5 illustrate a heat exchanger 10 (e.g., a
recuperator) for use in a microturbine, and/or a high-temperature
fuel cell. In other embodiments, the heat exchanger 10 can be
included in a vehicle having an internal combustion engine and can
operate as an exhaust gas waste heat recovery system, or
alternatively, as a portion of an exhaust gas waste heat recovery
system. In yet other embodiments, the heat exchanger 10 can be
included and/or used with oxide fuel cell-based auxiliary power
units installed in vehicles (e.g., recreational vehicles,
commercial or industrial vehicles, and the like). In still other
embodiments, the heat exchanger 10 can be used in other
applications (e.g., non-vehicular applications), such as, for
example, in electronics cooling, industrial equipment, building
heating and air-conditioning, and the like.
[0019] In some embodiments, the heat exchanger 10 can provide high
heat transfer effectiveness with minimal size and weight, a
low-cost construction due to a minimization of scrap material,
easily accessible joints and connection points for simplified
repair and location of leaks and other failures during or after
manufacture, and/or a thermally unconstrained design. In other
embodiments, the heat exchanger 10 can include one or more
additional features or advantages not specified herein.
[0020] In the illustrated embodiment of FIGS. 1-5, the heat
exchanger 10 transfers heat energy from a high temperature first
working fluid (e.g., exhaust gas, water, CO.sub.2, an organic
refrigerant, R12, R245fa, air, and the like) to a lower temperature
second working fluid (e.g., exhaust gas, water, CO.sub.2, an
organic refrigerant, R12, R245fa, air, and the like).
[0021] As shown in FIGS. 1-5, the heat exchanger 10 can include a
core 60 having a first sheet or separator sheet 12 and a number of
second sheets 16. In the illustrated embodiment of FIG. 2, the core
60 includes twenty-one second sheets 16 and a single first sheet
12. In other embodiments, the core 60 can include two or more first
sheets 12 and one, two, three, or more second sheets 16.
[0022] In the illustrated embodiment of FIGS. 1-5, the first sheet
12 is contoured and includes a number of fins, peaks, or
corrugations 22 and a number of channels 14 positioned between the
peaks 22. In addition, each of the second sheets 16 is contoured
and includes a number of fins, peaks, or corrugations 26 and a
number of channels 28.
[0023] In the illustrated embodiment, each of the peaks 22 of the
first sheet 12 and each of the peaks 26 of the second sheets 16 has
a substantially rounded end, and each of the channels 14 of the
first sheet 12 and each of the channels 28 of the second sheets 16
and has a similarly rounded cross section. In other embodiments,
the peaks 22 and/or channels 14 of the first sheet 12 and/or the
peaks 26 and the channels 28 of the second sheets 16 can be
pointed, squared, or irregularly shaped. In yet other embodiments,
the first sheet 12 and/or the second sheets 16 can have a
substantially saw-tooth shape. In still other embodiments, adjacent
peaks 22 and/or channels 14 of the first sheet 12 and/or adjacent
peaks 26 and/or channels 28 of the second sheets 16 can have
different shapes.
[0024] In some embodiments, the peaks 22 and channels 14 can be
formed by folding or corrugating the first sheet 12, and the peaks
26 and the channels 28 can be formed by folding or corrugating the
second sheets 16. In other embodiments, the first sheet 12 and/or
the second sheets 16 can be cast or molded in a desired shape.
[0025] The first sheet 12 and/or the second sheets 16 can be
manufactured from one or more materials suitable for operation in a
high-temperature heat exchanger. In some embodiments, the first
sheet 12 and the second sheets 16 can be manufactured from a high
nickel content alloy. In some embodiments, the first sheet 12 and
the second sheets 16 can be manufactured from materials having
substantially the same or substantially similar coefficients of
thermal expansion. In other embodiments, the first sheet 12 and/or
the second sheets 16 can be manufactured from other materials
(e.g., aluminum, iron, and other metals, composite material, and
the like).
[0026] As shown in FIGS. 1-5, the second sheets 16 can be
positioned in channels 1]4 of the first sheet 12 between upper and
lower ends of the peaks 22 of the first sheet 12. In some
embodiments, the second sheets 16 can be positioned in the channels
14 between alternating pairs of peaks 22 of the first sheet 12. In
other embodiments, the second sheets 16 can be positioned at
regular or irregular intervals between pairs of peaks 22 of the
first sheet 12.
[0027] In the illustrated embodiment of FIGS. 1-5, the second
sheets 16 are thinner than the first sheet 12. In other
embodiments, each of the second sheets 16 can have a different
thickness. Alternatively or in addition, one or more of the second
sheets 16 can have a thickness that is greater than or
substantially equal to the thickness of the first sheet 12,
depending upon the flow characteristics (e.g., flow rate,
temperature, pressure, etc.) of the first working fluid and/or the
second working fluid, the particular first working fluid selected,
the mass flow rate of the first working fluid through the heat
exchanger 10, the particular second working fluid selected, the
mass flow rate of the second working fluid through the heat
exchanger I 0, and the like.
[0028] In some embodiments, surface convolutions can be formed
along the inner or outer surface of one or more of the second
sheets 16. In some such embodiments, the surface convolutions can
include louvers, offset lances, bumps, channels, recesses, ribs,
etc. In other embodiments, surface convolutions can be formed along
the inner or outer surfaces of the first sheet 12. In these
embodiments, the surface convolutions can increase the rigidity or
strength of the core 60, improve the rate of heat transfer between
the first working fluid and the second working fluid, and/or
improve the efficiency of the heat exchanger 10. By improving the
efficiency of the heat exchanger 10, the inclusion of such surface
convolutions can also or alternatively ensure effective operation
of the heat exchanger 10 while minimizing the amount of material
required to manufacture the heat exchanger 10.
[0029] As shown in FIGS. 1 and 2, the first sheet 12 and the second
sheets 16 can be sized such that the corrugation height h of the
second sheets 16 is substantially similar to the space d between
adjacent peaks 22 of the first sheet 12 (i.e., the width of the
channels 14 of the first sheet 12). In this manner, the second
sheets 16 can be securely nested between adjacent peaks 22 of the
first sheet 12.
[0030] In some embodiments, such as the illustrated embodiment of
FIGS. 1-5, the width W of the first sheet 12 can be greater than
the width w of the second sheets 16 such that an unfinned section
20, 21 is located on either side of each second sheet 16 within
each channel 14 of the first sheet 12. In other embodiments, the
width W of the first sheet 12 can be less than or substantially
equal to the width w of one or more of the second sheets 16 such
that no unfinned sections are located along one or more of the
channels 14 of the first sheet 12. In these embodiments, the second
sheets 16 can provide structural support and rigidity to the core
60. In embodiments in which the pressure of one of the first
working fluid and the second working fluid is significantly greater
than the pressure of the other of the first working fluid and the
second working fluid, the additional structural support and
rigidity provided by the second sheets 16 can prevent or reduce
wear or damage to the core 60. In other embodiments, unfinned
sections 20, 21 are located at only one end of one or more of the
channels 14 of the first sheet 12.
[0031] In some embodiments, one or more of the second sheets 16 can
be secured to the first sheet 12 between adjacent peaks 22 of the
first sheet 12. In some such embodiments, the peaks 26 of the
second sheets 16 are connected (e.g., welded, soldered, brazed,
etc.) to the first sheet 12. In other embodiments, the second
sheets 16 can be supported in the channels 14 for movement relative
to the first sheet 12, or alternatively, the second sheets 16 can
be connected to the first sheet 12 in another manner, such as, for
example, by an interference fit, adhesive or cohesive bonding
material, fasteners, etc.
[0032] As shown in FIGS. 1-5, the heat exchanger 10 can also or
alternatively include a housing or enclosure 50. In some
embodiments, the housing 50 can be formed from a third sheet 30,
which can be wrapped around two or three sides of the core 60.
Alternatively or in addition, the third sheet 30 can include tabs
32, which can be bent or shaped to extend across one or more of the
channels 14 (e.g., the upwardly opening channels 14 shown in FIG.
5) of the first sheet 12. As shown in FIGS. 1-5, the tabs 32 can
extend across opposite ends of alternating channels 14 of the first
sheet 12. In other embodiments, the tabs 32 can extend across one
or both ends of adjacent channels 14. In some embodiments having
tabs 32, the tabs 32 can be secured (e.g., welded, soldered,
brazed, etc.) to the first sheet 12 to seal or substantially seal
the ends of the channels 14. In other embodiments, the tabs 32 can
be connected to the first sheet 12 in another manner, such as, for
example, by an interference fit, adhesive or cohesive bonding
material, fasteners, etc.
[0033] In some embodiments, such as the illustrated embodiment of
FIGS. 1-5, a surface 36 of the third sheet 30 can be secured to the
peaks 22 of the first sheet 12. Alternatively or in addition, ends
of the third sheet 30 can define flanges 40, which can extend
outwardly across side walls 42 of the core 60. In the illustrated
embodiment of FIGS. 1-5, the flanges 40 extend across front and
rear peaks 22 of the first sheet 12 so that the third sheet 30 at
least partially encloses the core 60.
[0034] In some embodiments, such as the illustrated embodiment of
FIGS. 1-5, the heat exchanger 10 can include a first flow path
(represented by arrows 62 in FIG. 4) for the first working fluid
and a second flow path (represented by arrows 64 in FIG. 3) for the
second working fluid. In the illustrated embodiment of FIGS. 1-5,
the heat exchanger 10 is configured as a single-pass heat exchanger
with the first working fluid traveling along the first flow path 62
through at least one of a number of channels 14 (i.e., the
downwardly opening channels 14 shown in FIGS. 1-5) defined by the
first sheet 12 and with the second working fluid traveling along
the second flow path 64 through at least one of a number of other
channels 14 (i.e., the upwardly opening channels 14 shown in FIGS.
1-5) defined by the first sheet 12. In these embodiments, the first
sheet 12 can separate the first and second flow paths 62, 64 and
can prevent mixing of the first and second working fluids.
[0035] In other embodiments, the heat exchanger 10 can be
configured as a multi-pass heat exchanger with the first working
fluid traveling in a first pass through one or more of the channels
14 and then traveling in a second pass through one or more
different channels 14 in a direction opposite to the flow direction
of the first working fluid in the first pass. In these embodiments,
the second working fluid can travel along the second flow path 64
through at least one of a number of other channels 14.
[0036] In yet other embodiments, the heat exchanger 10 can be
configured as a multi-pass heat exchanger with the second working
fluid traveling in a first pass through one or more of the channels
14 and then traveling in a second pass through one or more
different channels 14 in a direction opposite to the flow direction
of the second working fluid in the first pass. In these
embodiments, the first working fluid can travel along the first
flow path 62 through at least one of a number of other channels
14.
[0037] In still other embodiments, the heat exchanger 10 can be
configured as a multi-pass heat exchanger wherein the first working
fluid makes more than two consecutive passes through the heat
exchanger 10. In other embodiments, the heat exchanger 10 can be
configured as a multi-pass heat exchanger wherein the second
working fluid makes more than two consecutive passes through the
heat exchanger 10.
[0038] As shown in FIGS. 1-5, the first and second flow paths 62,
64 can be counter-directional. In other embodiments, the first and
second flow paths 62, 64 can be substantially parallel.
[0039] In embodiments such as the illustrated embodiment of FIGS.
1-5 having a first flow path 62 and a second flow path 64, the
housing 50 can define a first inlet 41 and a first outlet 43 for
the first flow path 62. As shown in FIGS. 1-5, the housing 50 can
also or alternatively define a second inlet 44 for the second flow
path 64 and a second outlet 45 for the second flow path 64.
[0040] In the illustrated embodiment of FIGS. 1-5, connectors 56,
58 are secured to the housing 50 around the second inlet 44 and the
second outlet 45, respectively. In some embodiments, the housing 50
can also include connectors located adjacent to the first inlet 41
and/or the first outlet 43 to prevent the first or second working
fluids from bypassing the core 60 or a portion of the core 60. In
some embodiments, the connectors 56, 58 provide the only points of
contact between the core 60 and the housing 50, thereby minimizing
or preventing unwanted heat transfer and ensuring that the core 60
remains thermally unconstrained. In addition, in some embodiments,
the housing 50 and/or the core 60 can include insulation and/or
refractory material to further minimize and/or prevent unwanted
heat transfer.
[0041] As shown in FIGS. 1-5, during operation of the heat
exchanger 10, the first working fluid can travel along the first
flow path 62 through the first inlet 41 into an inlet of one or
more of the channels 14 (i.e., one or more of the downwardly
opening channels 14 shown in FIGS. 1-5) adjacent to the first side
52 of the first sheet 12, through the second sheet 16 positioned in
the channel(s) 14, and out through the first outlet 43 adjacent to
the second side 54 of the first sheet 12.
[0042] As also shown in FIGS. 1-5, the second working fluid can
travel along the second flow path 64 through the second inlet 44
into one or more of the channels 14 (i.e., one or more of the
upwardly opening channels 14 shown in FIGS. 1-5), a first unfinned
section 20 of the channel(s) 14, the second sheet 16 positioned in
the channel(s) 14, the second unfinned section 21 of the channel(s)
14, and out the second outlet 45.
[0043] In the illustrated embodiment of FIGS. 1-5, the temperature
of the first working fluid at the first inlet 41 is greater than
the temperature of the second working fluid at the second inlet 44,
and heat energy is transferred from the first working fluid to the
second working fluid. Because the first flow path 62 is
substantially linear, impingement of the flow of the first working
fluid through the core 60 can be minimized.
[0044] During assembly, the first sheet 12 and one or more second
sheets 16 are contoured. The second sheets 16 are then inserted
into the channels 14 defined between the peaks 22 formed by the
first sheet 12. The third sheet 30 is then fitted around the first
sheet 12 to at least partially enclose the first sheet 12 and the
second sheets 16. In some embodiments, the second sheets 16 and the
third sheet 30 can be secured to the first sheet 12 in a single
operation (e.g., welded, soldered, brazed, etc.). In some such
embodiments, the tabs 32 can also or alternatively be secured to
the ends 52, 54 of the first sheet 12 during the same
operation.
[0045] In embodiments, such as the illustrated embodiment, in which
the core 60 is formed from a single first sheet 12 and one or more
second sheets 16 and in which the housing 50 is formed from a third
sheet 30, material usage can be minimized. In some such
embodiments, little or no scrap is generated during manufacture of
the heat exchanger 10.
[0046] In the illustrated embodiment of FIGS. 1-5, the only
connection points required to prevent cross-leakage between the
first flow path 62 and the second flow path 64 are located between
the edges of the tabs 32 and the contoured surface of the first
sheet 12. In some such embodiments, these connection points are
readily accessible during the manufacture of the heat exchanger 10,
thereby simplifying the identification and maintenance of leaks in
the heat exchanger 10.
[0047] Various features and advantages of the invention are set
forth in the following claims.
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