U.S. patent application number 14/994504 was filed with the patent office on 2017-07-13 for heat exchangers.
The applicant listed for this patent is Hamilton Sundstrand Corporation. Invention is credited to Michael K. Ikeda, Ram Ranjan, Brian St. Rock, Joseph Turney, Thomas M. Yun.
Application Number | 20170198976 14/994504 |
Document ID | / |
Family ID | 57708457 |
Filed Date | 2017-07-13 |
United States Patent
Application |
20170198976 |
Kind Code |
A1 |
Turney; Joseph ; et
al. |
July 13, 2017 |
HEAT EXCHANGERS
Abstract
A heat exchanger includes a body and a plurality of elliptical
flow channels defined in the body, the elliptical flow channels
defining an elliptical cross-sectional flow area, and a plurality
of non-elliptical flow channels defined in the body and
interspersed between the elliptical flow channels, the
non-elliptical flow channels having a non-elliptical
cross-sectional flow area.
Inventors: |
Turney; Joseph; (Amston,
CT) ; Ikeda; Michael K.; (West Hartford, CT) ;
St. Rock; Brian; (Andover, CT) ; Ranjan; Ram;
(West Hartford, CT) ; Yun; Thomas M.;
(Glastonbury, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hamilton Sundstrand Corporation |
Charlotte |
NC |
US |
|
|
Family ID: |
57708457 |
Appl. No.: |
14/994504 |
Filed: |
January 13, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28D 7/0066 20130101;
F28F 7/02 20130101 |
International
Class: |
F28D 7/00 20060101
F28D007/00 |
Claims
1. A heat exchanger, comprising: a body; and a plurality of
elliptical flow channels defined in the body, the elliptical flow
channels defining an elliptical cross-sectional flow area; and a
plurality of non-elliptical flow channels defined in the body and
interspersed between the elliptical flow channels, the
non-elliptical flow channels having a non-elliptical
cross-sectional flow area.
2. The heat exchanger of claim 1, wherein at least one of the
plurality of elliptical flow channels includes a circular
cross-sectional flow area.
3. The heat exchanger of claim 1, wherein at least one of the
plurality of non-elliptical flow channels includes a cross-shaped
or rounded-cross shaped cross-sectional flow area.
4. The heat exchanger of claim 1, wherein at least one of the
plurality of non-elliptical flow channels includes a rectilinear
shaped cross-sectional flow area.
5. The heat exchanger of claim 4, wherein the rectilinear shaped
cross-sectional area includes a hexagonal shape.
6. The heat exchanger of claim 1, wherein the elliptical flow
channels and the non-elliptical flow channels are uniformly defined
in the body such that the elliptical flow channels and
non-elliptical flow channels form an evenly spaced pattern.
7. The heat exchanger of claim 1, wherein the elliptical flow
channels are configured allow a hot flow to travel through the body
in a first direction.
8. The heat exchanger of claim 7, wherein the non-elliptical flow
channels are configured to allow a cold flow to travel through the
body in a second direction.
9. The heat exchanger of claim 8, wherein the first and second
directions are opposite.
10. A method of exchanging heat from a hot flow to a cold flow,
comprising: flowing the hot flow through a plurality of elliptical
flow channels defined in a body of a heat exchanger, the elliptical
flow channels defining an elliptical cross-sectional flow area; and
flowing the cold flow through a plurality of non-elliptical flow
channels defined in the body and interspersed between the
elliptical flow channels, the non-elliptical flow channels having a
non-elliptical cross-sectional flow area.
11. The method of claim 10, wherein flowing the hot flow through
the elliptical channels includes flowing the hot flow in a first
direction, wherein flowing the cold flow through the non-elliptical
channels includes flowing the cold flow in a second direction,
wherein the first direction and second direction are opposite.
Description
BACKGROUND
[0001] 1. Field
[0002] The present disclosure relates to heat exchangers, more
specifically to more thermally efficient heat exchangers.
[0003] 2. Description of Related Art
[0004] Heat exchangers are can be critical to the functionality of
numerous systems (e.g., aircraft systems, engines, environmental
control systems). Traditional heat exchangers include a plate fin
construction, with tube shell and plate-type heat exchangers having
niche applications. Traditional plate fin designs impose multiple
design constraints that inhibit performance, increase size and
weight, suffer structural reliability issues, are unable to meet
certain high temperature applications, and limit system integration
opportunities.
[0005] Such conventional methods and systems have generally been
considered satisfactory for their intended purpose. However, there
is still a need in the art for improved heat exchangers. The
present disclosure provides a solution for this need.
SUMMARY
[0006] A heat exchanger includes a body and a plurality of
elliptical flow channels defined in the body, the elliptical flow
channels defining an elliptical cross-sectional flow area, and a
plurality of non-elliptical flow channels defined in the body and
interspersed between the elliptical flow channels, the
non-elliptical flow channels having a non-elliptical
cross-sectional flow area.
[0007] At least one of the plurality of elliptical flow channels
can include a circular cross-sectional flow area. At least one of
the plurality of non-elliptical flow channels can include a
cross-shaped or rounded-cross shaped cross-sectional flow area.
[0008] In certain embodiments, at least one of the plurality of
non-elliptical flow channels can include a rectilinear shaped
cross-sectional flow area. For example, the rectilinear shaped
cross-sectional area can include a hexagonal shape.
[0009] The elliptical flow channels and the non-elliptical flow
channels can be uniformly defined in the body such that the
elliptical flow channels and non-elliptical flow channels form an
evenly spaced pattern. Any other suitable pattern is contemplated
herein.
[0010] In certain embodiments, the elliptical flow channels can be
configured to allow a hot flow to travel through the body in a
first direction. The non-elliptical flow channels can be configured
to allow a cold flow to travel through the body in a second
direction. In certain embodiments, the first and second directions
are opposite.
[0011] A method of exchanging heat from a hot flow to a cold flow
includes flowing the hot flow through a plurality of elliptical
flow channels defined in a body of a heat exchanger, the elliptical
flow channels defining an elliptical cross-sectional flow area, and
flowing the cold flow through a plurality of non-elliptical flow
channels defined in the body and interspersed between the
elliptical flow channels, the non-elliptical flow channels having a
non-elliptical cross-sectional flow area. In certain embodiments,
flowing the hot flow through the elliptical channels can include
flowing the hot flow in a first direction, wherein flowing the cold
flow through the non-elliptical channels can include flowing the
cold flow in a second direction, and the first direction and second
direction can be opposite.
[0012] These and other features of the systems and methods of the
subject disclosure will become more readily apparent to those
skilled in the art from the following detailed description taken in
conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] So that those skilled in the art to which the subject
disclosure appertains will readily understand how to make and use
the devices and methods of the subject disclosure without undue
experimentation, embodiments thereof will be described in detail
herein below with reference to certain figures, wherein:
[0014] FIG. 1 is a cross-sectional view of an embodiment of a heat
exchanger in accordance with this disclosure; and
[0015] FIG. 2 is a partial cross-sectional view of another
embodiment of a heat exchange in accordance with this
disclosure.
DETAILED DESCRIPTION
[0016] Reference will now be made to the drawings wherein like
reference numerals identify similar structural features or aspects
of the subject disclosure. For purposes of explanation and
illustration, and not limitation, an illustrative view of an
embodiment of a heat exchanger in accordance with the disclosure is
shown in FIG. 1 and is designated generally by reference character
100. Other embodiments and/or aspects of this disclosure are shown
in FIG. 2. The systems and methods described herein can be used to
reduce weight and/or increase performance of heat transfer
systems.
[0017] Referring to FIG. 1, a heat exchanger 100 includes a body
101 and a plurality of elliptical flow channels 103 defined in the
body 101. The elliptical flow channels 103 define an elliptical
cross-sectional flow area. The heat exchanger 100 includes a
plurality of non-elliptical flow channels 105 defined in the body
101. As shown, the non-elliptical flow channels 105 are
interspersed between the elliptical flow channels 103 and define a
non-elliptical cross-sectional flow area.
[0018] At least one of the plurality of elliptical flow channels
103 can include a circular cross-sectional flow area. As shown,
each elliptical flow channel 103 can be circular throughout the
heat exchanger 100, however, it is contemplated that the
cross-sectional shape and/or size can vary from channel to channel,
as a function of width, and/or along one or more flow directions.
For example, the diameter /shape of elliptical flow channel 103
and/or the size/shape of the non-elliptical flow channel 105 can
become smaller along a flow direction. Any other suitable variance
of the elliptical flow channels 103 is contemplated herein.
[0019] As shown in the embodiment of FIG. 1, at least one of the
plurality of non-elliptical flow channels 105 can include a
cross-shaped or rounded-cross shaped cross-sectional flow area.
Such shapes can reduce the amount of material that forms the body
101 and improve thermal transfer efficiency by increasing primary
heat transfer surface area (e.g., the surfaces where heat transfers
through the thickness of the material of the body 101) and
decreasing secondary heat transfer surface area (surfaces where
heat must travel along a length of material of the body 101). For
example, as shown, the free form rounded-cross shape can be
utilized to maintain a constant wall thickness throughout the heat
exchanger 100.
[0020] Referring to FIG. 2, in certain embodiments, at least one of
the plurality of non-elliptical flow channels 205 of heat exchanger
200 can be defined by the body 201 to include a rectilinear shaped
cross-sectional flow area. For example, the rectilinear shaped
cross-sectional flow area can include a hexagonal shape.
[0021] Referring again to FIG. 1, the elliptical flow channels 103
and the non-elliptical flow channels 105 can be uniformly defined
in the body 101 such that the elliptical flow channels 103 and
non-elliptical flow channels 105 form an evenly spaced pattern
(e.g., as in a checkerboard). Any other suitable pattern is
contemplated herein.
[0022] In certain embodiments, the elliptical flow channels 105 can
be configured to allow a hot flow to travel through the body 101 in
a first direction. For example, the elliptical flow channels 103
can converge at one or more ends of the heat exchanger 100 to form
a header to receive a hot flow (e.g., a hot coolant). Similarly,
the non-elliptical flow channels 105 can be configured to allow a
cold flow to travel through the body 101 in a second direction. In
certain embodiments, the first and second directions can be
opposite each other to provide a counter flow, however, the same
flow direction for hot and cold flow is contemplated herein.
[0023] In certain embodiments, the heat exchanger can be
monolithically formed using additive manufacturing. It is
contemplated that embodiments of the heat exchanger 100 can be
manufactured in any other suitable manner (e.g., casting, milling).
The heat exchanger 100 can include the structure as shown as at
least part of a core of the heat exchanger 100, with any suitable
header attached thereto or formed thereon.
[0024] In accordance with at least one aspect of this disclosure, a
method of exchanging heat from a hot flow to a cold flow can
include flowing the hot flow through a plurality of elliptical flow
channels 103 as described above. The method also includes flowing
the cold flow through a plurality of non-elliptical flow channels
as described above. In certain embodiments, flowing the hot flow
through the elliptical channels can include flowing the hot flow in
a first direction, and flowing the cold flow through the
non-elliptical channels can include flowing the cold flow in a
second direction. As described above, the first direction and
second direction can be opposite.
[0025] Embodiments described above allow maximization of primary
surface area for heat exchange while allowing flexibility to
increase or decrease the ratio of hot side to cold side flow area.
Changing the relative amount of flow area on each side of the heat
exchanger can allow full utilization of a pressure drop available
on each side. For example, the procedure by which the relative
amount of flow area on each side is changed can involve changing
the channel dimensions along the flow direction of the
channels.
[0026] Further, when high pressures are present, the shape of the
channels can be critical to achieving a low stress structure with a
low mass (e.g., small wall thickness). Ellipses (e.g., circles) are
particularly well suited to contain high pressures of hot side flow
since such shapes eliminate or reduce bending moments on the body
101. However, using elliptical channels (e.g., circles) for both
the high and low pressure side is unnecessary and results in
significant wasted space due to packing inefficiency resulting in
larger and heavier heat exchangers. As described above, combining
elliptical (e.g., circular) channels 103 for the high pressure
(e.g., hot side) flow with non-elliptical (e.g.,
polygonal/rectilinear/freeform) channels 105 for the lower pressure
flow (e.g., in a checkerboard like pattern) can result in more
efficient space utilization and reduction of material.
[0027] Embodiments utilizing counter flow (e.g., as opposed to
cross flow or) can provide improved performance by enabling
improved balancing of the hot and cold side heat transfer and
pressure drop, as well as increasing the heat exchanger
effectiveness for a given overall heat transfer area. Counter flow
can reduce the temperature differential across the heat exchanger
planform since the cold side outlet is aligned with the hot side
inlet, and vice versa.
[0028] Embodiments of this disclosure also have significant
structural benefits that enable higher temperature and higher
pressure operation over traditional devices. For example,
embodiments as described above can allow heat transfer area and
structural support to inlet and outlet headers. The above described
features can be used to address transient thermal stress issues
since the temperature response of the header and the core can be
matched more closely than in a traditional open header.
[0029] The methods and systems of the present disclosure, as
described above and shown in the drawings, provide for heat
exchangers with superior properties including reduced weight and/or
increased efficiency. While the apparatus and methods of the
subject disclosure have been shown and described with reference to
embodiments, those skilled in the art will readily appreciate that
changes and/or modifications may be made thereto without departing
from the spirit and scope of the subject disclosure.
* * * * *