U.S. patent application number 14/304020 was filed with the patent office on 2015-12-17 for heat exchanger designs using variable geometries and configurations.
This patent application is currently assigned to HONEYWELL INTERNATIONAL INC.. The applicant listed for this patent is HONEYWELL INTERNATIONAL INC.. Invention is credited to Jorge D. Alvarez, Douglas Michael Czaplicki, Karl Fleer, Donald G. Godfrey, Mark C. Morris.
Application Number | 20150361922 14/304020 |
Document ID | / |
Family ID | 54835764 |
Filed Date | 2015-12-17 |
United States Patent
Application |
20150361922 |
Kind Code |
A1 |
Alvarez; Jorge D. ; et
al. |
December 17, 2015 |
HEAT EXCHANGER DESIGNS USING VARIABLE GEOMETRIES AND
CONFIGURATIONS
Abstract
A heat exchanger may include at least one fluid passageway
adjacent a heat transfer plate and a plurality of heat transfer
elements positioned in the at least one fluid passageway and joined
with the heat transfer plate. The heat transfer elements may be
positioned with first spacings therebetween at an inlet end of the
at least one fluid passageway. The heat transfer elements may be
positioned with second spacings therebetween at an outlet end of
the at least one fluid passageway. The first spacings may be
smaller than the second spacings.
Inventors: |
Alvarez; Jorge D.; (Buena
Park, CA) ; Czaplicki; Douglas Michael; (Culver City,
CA) ; Fleer; Karl; (San Pedro, CA) ; Morris;
Mark C.; (Phoenix, AZ) ; Godfrey; Donald G.;
(Phoenix, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HONEYWELL INTERNATIONAL INC. |
MORRISTOWN |
NJ |
US |
|
|
Assignee: |
HONEYWELL INTERNATIONAL
INC.
MORRISTOWN
NJ
|
Family ID: |
54835764 |
Appl. No.: |
14/304020 |
Filed: |
June 13, 2014 |
Current U.S.
Class: |
165/185 |
Current CPC
Class: |
F28D 9/0081 20130101;
F28F 2215/04 20130101; B33Y 80/00 20141201; F05D 2260/213 20130101;
F02C 7/185 20130101; F04D 29/582 20130101; F04D 27/009 20130101;
F05D 2260/2214 20130101; F28D 9/02 20130101; Y02T 50/60 20130101;
F28D 2021/0021 20130101; F02C 7/047 20130101; F28F 9/0268 20130101;
F01D 25/02 20130101; Y02T 50/675 20130101 |
International
Class: |
F02K 3/115 20060101
F02K003/115 |
Claims
1. A heat exchanger comprising: at least one fluid passageway
adjacent a heat transfer plate; and a plurality of heat transfer
elements positioned in the at least one fluid passageway and joined
with the heat transfer plate, the heat transfer elements being
positioned with first spacings therebetween at an inlet end of the
at least one fluid passageway, the heat transfer elements being
positioned with second spacings therebetween at an outlet end of
the at least one fluid passageway, and the first spacings being
smaller than the second spacings.
2. The heat exchanger of claim 1 wherein intermediate heat transfer
elements are interposed between the inlet end and the outlet end
and are positioned with varying spacings therebetween, said varying
spacings progressively increasing in the direction of inlet end to
outlet end of the at least one fluid passageway.
3. The heat exchanger of claim 1 wherein all of the heat transfer
elements are fins oriented orthogonally to the heat transfer
plate.
4. The heat exchanger of claim 3: wherein the fins have a first
thickness at the inlet end of the at least one fluid passageway;
wherein the fins have a second thickness at the outlet end of the
at least one fluid passageway; and wherein the first thickness is
greater than the second thickness.
5. The heat exchanger of claim 3: wherein the heat transfer plate
varies in thickness between the inlet end and the outlet end of the
at least one fluid passageway; and wherein the at least one fluid
passageway varies in height between the inlet end and the outlet
end of the fluid passageway.
6. The heat exchanger of claim 3 wherein fillets are present at
joining locations of the fins and the at least one heat transfer
plate.
7. The heat exchanger of claim 6: wherein the fillets have a first
radius at the joining locations of the fins at the inlet end of the
heat transfer plate; wherein the fillets have a second radius at
the joining locations of the fins at the outlet end of the heat
transfer plate; and wherein the first radius is greater than the
second radius.
8. The heat exchanger of claim 1: wherein the at least one transfer
plate has a first thickness at the inlet end of the fluid
passageway and has a second thickness at the outlet end of the
fluid passageway; and wherein the first thickness of the heat
transfer plate is greater than the second thickness of the heat
transfer plate.
9. Apparatus for cooling bleed air extracted from an aircraft
engine comprising: at least one fluid passageway adjacent a heat
transfer plate; a plurality of fins positioned in the at least one
fluid passageway and joined with the heat transfer plate; and at
least one de-icing channel formed in the at least one fluid
passageway, wherein none of the fins are present in the at least
one de-icing passageway, wherein the at least one de-icing channel
extends from an inlet end to an outlet end of the at least one
fluid passageway, and wherein a length of the at least one de-icing
channel is greater than a length of the at least one fluid
passageway.
10. The apparatus of claim 9: wherein fillets are present at
joining locations of the fins and the at least one heat transfer
plate; wherein the fillets have a first radius at the joining
locations of the fins at an inlet end of the heat transfer plate;
wherein the fillets have a second radius at the joining locations
of the fins at an outlet end of the heat transfer plate; and
wherein the first radius is greater than the second radius.
11. The apparatus of claim 9 wherein the at least one de-icing
passageway has a serpentine configuration
12. The apparatus of claim 9 wherein the heat transfer plate
comprises a flow channeling segment and a main heat transfer
segment.
13. The apparatus of claim 12 wherein curved fins are joined to the
flow channeling segment.
14. The apparatus of claim 9 further comprising: a plurality of the
fluid passageways each fluidly isolated from one another by a one
of the heat transfer plates so that first fluid passageways are
interposed between second fluid passageways and so that adjacent
ones of the first and second fluid passageways are thermally
coupled to one another ; wherein the fins are oriented parallel to
fluid flow in a first direction within the first fluid passageways;
wherein the fins are oriented parallel to fluid flow in a second
direction within the second fluid passageways; and wherein the
fluid flow in the first direction is orthogonal to the fluid flow
in the second direction.
15. The apparatus of claim 14 wherein each of the first fluid
passageways contains at least one of the de-icing passageways.
16. The apparatus of claim 14 wherein fillets are present at
joining locations of the fins and the heat transfer plates.
17. A method for cooling bleed air comprising the steps: passing
bleed air through first fluid passageways of a heat exchanger, the
second fluid passageways being thermally coupled with the first
fluid passageways; and passing ambient air through second fluid
passageways of the heat exchanger; wherein the step of passing
bleed air through the first fluid passageways comprises, a) passing
bleed air around first fins having a first thickness at an inlet
end of the first fluid passageways so the first fins absorb heat at
a maximum temperature differential of the heat exchanger, and b)
passing bleed air around second fins having a second thickness,
less than the first thickness, at an outlet end of the first fluid
passageways so that the second fins produce less bleed air pressure
drop than the first fins.
18. The method of claim 17 further comprising the step of passing
the bleed air around curved fins at the inlet end of the first
fluid passageways to channel bleed air flow through the heat
exchanger.
19. The method of claim 17 further comprising passing bleed air
through de-icing channels within the first fluid passageways along
paths that are longer than the first fluid passageways.
20. The method of claim 19 wherein the step of passing bleed air
through de-icing channels comprises passing the bleed air along
serpentine paths.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to heat exchangers
and, more specifically, to heat exchangers employed in applications
that involve high temperature differentials and high pressures.
[0002] Heat exchangers employed in high temperature applications
may be subject to various stresses which may cause damage and
ultimately failure. For example, high stress heat exchangers may be
employed in aircraft to cool bleed air from an engine compressor.
In these circumstances, bleed air may emerge from an engine at
temperatures in excess of 1000.degree. F. The bleed air may enter a
heat exchanger for cooling with ambient air so that the bleed air
may be safely utilized in an aircraft environmental control system
(ECS). At a typical cruise altitude of an aircraft, ambient air may
have a temperature as low as negative 60.degree. F. Thus, various
elements of such a heat exchanger may be exposed to an operating
temperature differential of almost 1100.degree. F.
[0003] In conventional heat exchangers, various elements are joined
together with welded or brazed joints. These joints are subjected
to thermal stresses when they are exposed to temperature
differentials. The joints may also be subjected to stresses when
air or fluid is introduced into the heat exchanger at high
pressure. Collectively these stresses may cause fatigue-induced
failure of the joints. Such failures may cause leakage in the heat
exchanger and ultimately may shorten overall life-span of the heat
exchanger.
[0004] It has been found that tubular type heat exchangers, as
compared to plate-fin type heat exchangers, may have a higher
tolerance for operating in conditions that produce high pressure
and high temperature differentials. On the other hand, tubular type
heat exchangers are typically more costly to manufacture and
typically have a higher weight than their fin type
counterparts.
[0005] In some aircraft applications, heat exchangers may be
subject to ice formation when an aircraft is allowed to remain idle
at ground level in a cold environment. Ice may form on closely
spaced fins as water vapor condenses after cessation of airflow
through the heat exchanger. When the aircraft is re-started,
operation of the heat exchangers must be delayed until the heat
exchanger is de-iced.
[0006] As can be seen, there is a need for heat exchangers that
have a high tolerance for operating under conditions that involve
high temperature differentials and/.or high pressures. Moreover
there is a need for a plate-fin type heat exchanger that may meet
or exceed capabilities of a tubular-type heat exchanger. Further
still, there is a need for a heat exchanger that may be rapidly
de-iced when employed in an aircraft
SUMMARY OF THE INVENTION
[0007] In one aspect of the present invention, a heat exchanger may
comprise: at least one fluid passageway adjacent a heat transfer
plate; and a plurality of heat transfer elements positioned in the
at least one fluid passageway and joined with the heat transfer
plate, the heat transfer elements being positioned with first
spacings therebetween at an inlet end of the at least one fluid
passageway, the heat transfer elements being positioned with second
spacings therebetween at an outlet end of the at least one fluid
passageway, and the first spacings being smaller than the second
spacings.
[0008] In another aspect of the present invention, apparatus for
cooling bleed air extracted from an aircraft engine may comprise:
at least one fluid passageway adjacent a heat transfer plate; a
plurality of fins positioned in the at least one fluid passageway
and joined with the heat transfer plate; and at least one de-icing
channel formed in the at least one fluid passageway, wherein none
of the fins are present in the at least one de-icing passageway,
wherein the at least one de-icing channel extends from an inlet end
to an outlet end of the at least one fluid passageway, and wherein
a length of the at least one de-icing channel is greater than a
length of the at least one fluid passageway.
[0009] In still another aspect of the present invention, a method
for cooling bleed air may comprise the steps: passing bleed air
through first fluid passageways of a heat exchanger, the second
fluid passageways being thermally coupled with the first fluid
passageways; and passing ambient air through second fluid
passageways of the heat exchanger, wherein the step of passing
bleed air through the first fluid passageways may comprise, a)
passing bleed air around first fins having a first thickness at an
inlet end of the first fluid passageways so the first fins absorb
heat at a maximum temperature differential of the heat exchanger,
and b) passing bleed air around second fins having a second
thickness, less than the first thickness, at an outlet end of the
first fluid passageways so that the second fins produce less bleed
air pressure drop than the first fins.
[0010] These and other features, aspects and advantages of the
present invention will become better understood with reference to
the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a simplified exploded view of a heat exchanger in
accordance with an embodiment of the invention;
[0012] FIG. 2 is a partial cross sectional view of a small-radius
filleted joining location of a heat transfer fin in accordance with
an embodiment of the invention;
[0013] FIG. 3 is a partial cross sectional view of a large-radius
filleted joining location of a heat transfer fin in accordance with
a second embodiment of the invention;
[0014] FIG. 4 is a partial cross sectional view of an
intermediate-radius filleted joining location of a heat transfer
fin in accordance with an embodiment of the invention;
[0015] FIG. 5 is simplified plan view of a heat transfer plate and
fins in accordance with an embodiment of the invention;
[0016] FIG. 6 is a partial cross-sectional view of a
variable-height fluid passageway of a heat exchanger in accordance
with an exemplary embodiment of the invention;
[0017] FIG. 7 is simplified plan view of a heat transfer plate and
fins in accordance with a second embodiment of the invention;
[0018] FIG. 8 is simplified plan view of a heat transfer plate and
fins in accordance with a third embodiment of the invention;
[0019] FIG. 9 is a perspective view of a heat transfer plate and
de-icing channel in accordance with an embodiment of the invention;
and
[0020] FIG. 10 is a flow chart of a method for cooling bleed air in
accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The following detailed description is of the best currently
contemplated modes of carrying out the invention. The description
is not to be taken in a limiting sense, but is made merely for the
purpose of illustrating the general principles of the invention,
since the scope of the invention is best defined by the appended
claims.
[0022] Various inventive features are described below that can each
be used independently of one another or in combination with other
features.
[0023] The present invention generally provides heat exchangers in
which heat transfer elements may be constructed with varying shapes
and spacings to facilitate heat exchange between fluids at high
temperature differentials with minimal thermal and pressure induced
stress. More particularly, the present invention provides fin type
heat exchangers wherein fins may be connected to plates with
filleted connections. Further still, the present invention may
provide heat exchangers that may be rapidly de-iced.
[0024] Referring now to FIG. 1, there is shown a simplified
exploded view of a portion of an exemplary embodiment of a heat
exchanger 100. The heat exchanger 100 may include a first fluid
passageway 102 and a second fluid passageway 104. By way of
example, the first fluid passageway 102 may allow for passage of
bleed air from an aircraft engine (not shown) and the second fluid
passageway 104 may allow for passage of ambient air in which the
aircraft (not shown) may be operating. The fluid passageways 102
and 104 may be separated from another with heat transfer plates
106. The first fluid passageway 102 may have an input end 108 and
an output end 110. The second fluid passageway 104 may have an
input end 112 and an output end 114. Each of the heat transfer
plates 106 may have a plurality of heat transfer elements or fins
116 connected and oriented orthogonally to the heat transfer plates
106.
[0025] Referring now to FIGS. 2, 3 and 4, it may be seen that the
fins 116 may be connected to their respective ones of the heat
transfer plates 105 with filleted connections. Construction of the
plates 106 and the fins 116 may be performed by employing an
additive layer fabrication system such as that described in US
Published Patent Application 20130236299, dated Sep. 13, 2013,
which application is incorporated by reference herein.
[0026] It may be noted that a large-radius fillet 118 may be
employed at connections between the fins 116 and the plates 106 at
the inlet end 108 of the fluid passageway 102. Even though the
large-radius fillets 118 may increase a pressure drop in incoming
bleed air, the large-radius fillets 118 may provide
counterbalancing advantages. Temperature differential and a
potential for thermal stress is at its highest at the inlet end
114. A large fillet radius may have the desirable effect of
offsetting or minimizing thermal stress.
[0027] It may also noted that small-radius fillets 120 may be
employed at connections between the fins 116 and the plates 106 at
or near the outlet end 110 of the fluid passageway 102. As compared
to the inlet end 108, temperature differentials are lower at the
outlet end of the fluid passageway 102. Consequently, thermal
stresses may be lower and the small-radius fillets 120 may have
less of a pressure-drop inducing effect.
[0028] At positions intermediate between the inlet end 108 and the
outlet end 110 of the fluid passageway, the fins 116 may be
connected with intermediate radius fillets 112 such as those
illustrated in FIG. 4. Here again, the radius of the fillets 122
may be selected to achieve a desirable balance between stress
reduction and induced pressure drop.
[0029] Referring now to FIG. 5, there is shown a simplified view of
a pattern of fin placement on one of the heat transfer plates 106.
In the exemplary embodiment of FIG. 5, it may be seen that the fins
116 located at or near the inlet end 108 may be spaced apart from
one another by a distance D1. In comparison, the fins 116 located
at or near the outlet end 110 may be spaced apart from one another
by a larger distance D2. The fins 116 may be arranged in successive
rows, for example rows 130, 132, 134, 136 and 138. Spacing between
the fins 116 may progressively increase within each successive row.
For example, fin spacing in row 132 may be greater than fin spacing
in row 130. Similarly, fin spacing in row 134 may be greater than
fin spacing in row 132. In other words, fin spacing may
progressively increase in the direction of fluid flow from the
inlet end 108 to the outlet end 110. While FIG. 5 may illustrate
five exemplary rows, it should be noted that any number of rows may
be placed between the inlet end 108 and the outlet end 110.
[0030] It may be seen that the fins 116 located at or near the
inlet end 108 may have a thickness T1. In comparison, the fins 106
located at or near the outlet end 110 may have a smaller thickness
T2. Thickness of the fins 116 may progressively decrease within
each successive row. For example, fin thickness in row 132 may be
less than fin thickness in row 130. Similarly, fin thickness in row
134 may be less than fin thickness in row 132. In other words, fin
thickness may progressively decrease in the direction of fluid flow
from the inlet end 108 to the outlet end 110.
[0031] Referring now to FIG. 6, it may be seen that in an exemplary
embodiment, the heat transfer plate 106 may have a varying
thickness along its length in the direction of fluid flow. The
plate 106 may be thickest at the inlet end 108 and thinnest at the
outlet end 110. Additionally, heights of the fins 116 may vary
progressively from row to row. Consequently the fluid passageways
102 and/or 104 may have a varying height along their respective
lengths.
[0032] Referring now to FIGS. 7 and 8, there are shown simplified
views of exemplary embodiments of a heat transfer plate 140. The
plate 140 may be non-rectilinear and may include a flow channeling
segment 142 and a main heat transfer segment 144. Within the
segment 144, fins 116 may be arranged in the configuration
discussed above with respect to FIG. 5. Within the flow channeling
segment 142, flow channeling fins 146 may be employed to
concentrate fluid flow. The flow channeling fins 146 may have
various configurations (e.g., curved fins, pin fins and/or offset
fins). Referring now to FIG. 9, an exemplary embodiment of a heat
transfer plate 150 may include a de-icing segment 152. A heat
transfer plate such as the one illustrated in FIG. 9 may be
particularly effective in aircraft applications. A fin type heat
exchanger may be subject to ice formation when an aircraft is
allowed to remain idle at ground level in a cold environment. Ice
may form on closely spaced fins as water vapor condenses after
cessation of airflow through the heat exchanger. When the aircraft
is re-started, operation of the heat exchangers must be delayed
until the heat exchanger is de-iced.
[0033] De-icing may be performed quickly when warm fluid passes
through the de-icing segment 152. The de-icing segment 152 may not
have any of the fins 116 or 146 connected thereto. Thus fluid, such
as air, may pass unimpeded through a de-icing channel 154 formed
between some of the fins 116 or 146 and the de-icing segment 152.
The de-icing segment 152 and the corresponding de-icing channel 154
may have a length that exceeds an overall length of the plate 150.
The de-icing channel may be constructed with various
configurations. In an exemplary embodiment of FIG. 9, the de-icing
channel 154 may be formed in a serpentine shape.
[0034] Advantageously, the serpentine shape facilitates de-icing
fluid flow into a substantial area of the heat transfer plate 150.
Thus the fins 116 and/or 146 may be quickly de-iced because a need
to laterally transfer heat from one fin to the next may be
minimized. In other words, the serpentine shaping of the de-icing
channel 154, as compared to a straight line shape, may result in a
reduction of lateral distance between the fins and the de-icing
channel 154.
[0035] It may seen, from FIGS. 6, 7, 8 and 9, that the heat
exchanger 100 may be constructed with various non-rectilinear
elements. This non-rectilinear shaping of elements may provide
advantageous operational features for the heat exchanger 100. As
discussed above, a wide range of element shapes may be provided
efficiently and cost-effectively by employing additive fabrication
methods.
[0036] Referring now to FIG. 10, a flow chart illustrates an
exemplary embodiment of a method 900 for cooling bleed air on an
aircraft. In a step 902, bleed air may be passed into first fluid
passageways of a heat exchanger (e.g., bleed air may be passed into
fluid passageways 102). In a step 904, the bleed air may be passed
around thick fins (e.g., the bleed air may pass around the fins 116
at the inlet end 108 of the first fluid passageway 102). In a step
906, the bleed air may be passed around thin fins (e.g., the bleed
air may pass around the fins 116 at the outlet end 110 of the first
fluid passageway 102). In a step 908 ambient air may be passed
through second fluid passageways (e.g., ambient air may be passed
through the fluid passageways 104). In a step 910 cooled bleed air
may be transferred to a conventional environmental control system
(ECS) of the aircraft.
[0037] It should be understood, of course, that the foregoing
relates to exemplary embodiments of the invention and that
modifications may be made without departing from the spirit and
scope of the invention as set forth in the following claims.
* * * * *