U.S. patent application number 15/836968 was filed with the patent office on 2018-06-21 for heat exchanger.
The applicant listed for this patent is HS Marston Aerospace Limited. Invention is credited to Neil BASINI.
Application Number | 20180172361 15/836968 |
Document ID | / |
Family ID | 57570746 |
Filed Date | 2018-06-21 |
United States Patent
Application |
20180172361 |
Kind Code |
A1 |
BASINI; Neil |
June 21, 2018 |
HEAT EXCHANGER
Abstract
A heat exchanger comprises a conduit with an interior surface
which defines a first flow passage. A first plurality of fins
project inwardly from the interior surface of the conduit. The
first plurality of fins are angled relative to a longitudinal axis
(X) of the conduit so as to form helical flowpaths for fluid
flowing through the first flow passage. A second flow passage
disposed outwardly of the interior surface and radially outwardly
of the first plurality of fins.
Inventors: |
BASINI; Neil;
(Wolverhampton, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HS Marston Aerospace Limited |
Wolverhampton |
|
GB |
|
|
Family ID: |
57570746 |
Appl. No.: |
15/836968 |
Filed: |
December 11, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28F 2250/08 20130101;
F28F 2250/10 20130101; F28F 1/36 20130101; F28F 1/40 20130101; F28D
7/0008 20130101; F28F 1/32 20130101; F28F 1/003 20130101; F28D 7/10
20130101; F28F 2215/04 20130101 |
International
Class: |
F28F 1/32 20060101
F28F001/32; F28F 1/36 20060101 F28F001/36 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 16, 2016 |
EP |
16275174.7 |
Claims
1. A heat exchanger comprising: a conduit with an interior surface,
wherein the interior surface defines a first flow passage; a first
plurality of fins projecting inwardly from the interior surface of
the conduit, wherein the plurality of fins are angled relative to a
longitudinal axis (X) of the conduit so as to form helical
flowpaths for fluid flowing through the first flow passage; and a
second flow passage disposed outwardly of the interior surface and
radially outwardly of the plurality of fins.
2. The heat exchanger of claim 1, wherein the first plurality of
fins are straight along their length.
3. The heat exchanger of claim 1, wherein the first plurality of
fins are at least partially curved along their length.
4. The heat exchanger of claim 1, wherein the first plurality of
fins are corrugated along their length.
5. The heat exchanger of claim 1, wherein the first plurality of
fins are distributed circumferentially around the interior surface
of the conduit.
6. The heat exchanger of claim 1, wherein the first plurality of
fins are distributed circumferentially around less than 50% of the
interior surface of the conduit.
7. The heat exchanger of claim 1, wherein the second flow passage
extends around less than 50% of the circumference of the
conduit.
8. The heat exchanger of claim 1, wherein the conduit further
comprises an exterior surface, and wherein the second flow passage
is disposed between the interior surface and exterior surface of
the conduit.
9. The heat exchanger of claim 1, wherein a second plurality of
fins project into the second flow passage, wherein, optionally, the
second plurality of fins are aligned with and/or are extensions of
said first plurality of fins.
10. The heat exchanger of claim 1, wherein the conduit
cross-section has a maximum diameter of less than 200 mm.
11. The heat exchanger of claim 1, wherein the conduit further
comprises an outlet, and wherein an angle formed between the first
plurality of fins and the longitudinal axis (X) of the conduit is
between 10.degree. and 45.degree., optionally wherein the angle
formed is between 10.degree. and 20.degree..
12. A system comprising: a heat exchanger that includes: a conduit
with an interior surface, wherein the interior surface defines a
first flow passage; a first plurality of fins projecting inwardly
from the interior surface of the conduit, wherein the plurality of
fins are angled relative to a longitudinal axis (X) of the conduit
so as to form helical flowpaths for fluid flowing through the first
flow passage; and a second flow passage disposed outwardly of the
interior surface and radially outwardly of the plurality of fins;
and a matrix with an inlet disposed downstream of the first flow
passage to receive the flow from the first flow passage.
13. The system of claim 12, wherein the matrix is one of a heat
exchanger matrix or an ozone converter matrix.
14. A method of operating the heat exchanger of claim 1, the method
comprising the steps of: providing a first fluid flow to an inlet
of the first flow passage, and a second fluid flow to an inlet of
the second flow passage; swirling the fluid flow in the helical
flowpaths in the first flow passage; and exchanging heat between
the first fluid flow and the second fluid flow.
15. A method of operating the system of claim 12, the method
comprising the steps of: providing a first fluid flow to an inlet
of the first flow passage, and a second fluid flow to an inlet of
the second flow passage; swirling the fluid flow in the helical
flowpaths in the first flow passage; exchanging heat between the
first fluid flow and the second fluid flow; and admitting the first
fluid flow into the inlet of the matrix.
Description
FOREIGN PRIORITY
[0001] This application claims priority to European Patent
Application No. 16275174.7 filed Dec. 16, 2016, the entire contents
of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a heat exchanger.
BACKGROUND
[0003] It is well-known in the art of fluid control to use a matrix
or lattice within a component to maximise a contact area for
interacting with a fluid flow. Increasing the contact area by using
a matrix improves, for example, the rate of heat exchange or
chemical reaction between the fluid flow and the component.
[0004] Components using a matrix typically comprise a conduit for
providing fluid flow to an inlet of the matrix. Typically, the
conduit cross-sectional area is less than that of the matrix inlet.
The matrix and the conduit are sized such that a flow from the
conduit can disperse throughout the entire matrix volume to
maximise the contact area. As such, providing a relatively wide
conduit with a slow fluid flow allows the flow to disperse
evenly.
[0005] However, some applications may require a narrow conduit.
This can result in a faster-moving fluid flow that does not
disperse fully across the matrix volume. This, in turn, can result
in a reduced efficiency and/or increased wear of the matrix.
[0006] Additionally, in fluid control applications using a matrix
as described above, there may be a need to impart or remove heat
from the fluid.
SUMMARY
[0007] According to an exemplary embodiment of the present
disclosure, there is provided a heat exchanger comprising a conduit
with an interior surface. The interior surface defines a first flow
passage. A first plurality of fins projects inwardly from the
interior surface of the conduit. The first plurality of fins are
angled relative to a longitudinal axis of the conduit so as to form
helical flowpaths for fluid flowing through the first flow passage.
A second flow passage is disposed outwardly of the interior surface
and radially outwardly of the first plurality of fins.
[0008] The fins may be straight along their length.
[0009] Alternatively, the fins may be at least partially curved.
The fins may be curved along their entire length, or the fins may
be straight at an inlet to the conduit and gradually curve to be
angled at the exit to the conduit.
[0010] Alternatively, the fins may be corrugated.
[0011] The first plurality of fins may be distributed around the
entire circumference of the interior surface of the conduit.
[0012] Alternatively, the fins may be distributed around less than
50% of the circumference of the interior surface of the conduit,
for example around 25% of the circumference of the interior surface
of the conduit.
[0013] The second flow passage may extend around the entire
circumference of the conduit. Alternatively the second flow passage
may extend around less than 50% of the circumference of the
conduit.
[0014] The second flow passage may be circumferentially coterminous
with the fins.
[0015] The conduit may further comprise an exterior surface,
wherein the second flow passage is disposed between the interior
surface and exterior surface of the conduit.
[0016] The conduit may comprise a second plurality of fins which
project into the second flow passage.
[0017] The second plurality of fins may be aligned with the first
plurality of fins. The second plurality of fins may be extensions
of the first plurality of fins.
[0018] The conduit cross-section may have a maximum diameter of
less than 200 mm. In certain embodiments, the conduit may have a
diameter of between 50 mm and 150 mm.
[0019] The conduit may further comprise an outlet, wherein an angle
formed between the fins and the longitudinal axis of the conduit at
the outlet is between 10.degree. and 45.degree., for example
between 10.degree. and 20.degree..
[0020] The heat exchanger cross-section may be annular.
[0021] The heat exchanger may be an air-liquid heat exchanger.
[0022] The plurality of fins may project less than 50% of the
radial distance between the interior surface and a centre of the
conduit, for example between 25% and 50% of the radius of the
conduit.
[0023] The fins may be evenly distributed on the interior surface
of the conduit.
[0024] In a further exemplary embodiment of the disclosure, a
system comprises the heat exchanger as described above. A matrix
with an inlet is disposed downstream of the first flow passage to
receive the flow from the first flow passage.
[0025] The matrix may be one of a heat exchanger matrix or an ozone
converter matrix.
[0026] The heat exchanger or system may be part of an aircraft
environmental control system.
[0027] In a further exemplary embodiment of the disclosure, a
method of operating the heat exchanger as described above comprises
the steps of providing a first fluid flow to an inlet of the first
flow passage, and a second fluid flow to an inlet of the second
flow passage, swirling the fluid flow in the helical flowpaths in
the first flow passage, and exchanging heat between the first fluid
flow and the second fluid flow.
[0028] In a further exemplary embodiment of the disclosure, a
method of operating the system as described above comprises the
steps of providing a first fluid flow to an inlet of the first flow
passage, and a second fluid flow to an inlet of the second flow
passage, swirling the fluid flow in the helical flowpaths in the
first flow passage, exchanging heat between the first fluid flow
and the second fluid flow, and admitting the first fluid flow into
the inlet of the matrix.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIGS. 1 to 3 show sectional views of heat exchangers in
accordance with this disclosure.
[0030] FIGS. 4A and 5A show oblique views of arrangements of the
conduit of the heat exchanger of FIG. 1.
[0031] FIGS. 4B and 5B show plan views of the conduits of FIGS. 4A
and 5A along lines 1-1 and 2-2 respectively.
[0032] FIGS. 4C and 5C show partial, enlarged views of the conduits
of FIGS. 4A and 5A respectively.
[0033] FIG. 6 shows an oblique view of a swirled flow dispersing
from a conduit into a downstream matrix inlet.
[0034] FIG. 7 shows an axial view of the swirled flow of FIG.
6.
DETAILED DESCRIPTION
[0035] FIG. 1 shows an example heat exchanger in accordance with
this disclosure. The heat exchanger comprises a conduit 16. In this
embodiment the conduit 16 is annular, and comprises an interior
surface 18 and an exterior surface 20. The conduit 16 has a
longitudinal axis X. A first flow passage 22 is defined by an
interior surface 18 of the conduit 16. A second flow passage 24 is
formed radially outwardly of the interior surface 18. In this
embodiment, the second flow passage 24 extends around less than 50%
of the circumference of the conduit 16, for example between 25% and
30% of the circumference. In this example, the second flow passage
24 is disposed between the interior surface 18 and the exterior
surface 20. In other examples, the second flow passage 24 may be
disposed outwardly of the exterior surface 20 and formed by a
separate member suitably attached to the conduit 16.
[0036] Heat exchange fins 26 project from the interior surface 18
into the first flow passage 22. The fins 26 are distributed around
the circumference of the conduit 16, extending inwardly from the
portion of the conduit 16 where the second flow passage 24 is
disposed. Hence, the fins 26 also extend around less than 50% of
the circumference of the conduit 16. In the example shown, the fins
26 extend less than 50% of the distance between the interior
surface 18 and the centre of the conduit 16. For example, the fins
may extend inwardly between 25 and 50% of the conduit radius.
[0037] Heat is exchanged between the first flow passage 22 and the
second flow passage 24 through the fins 26. Hence, substantial heat
exchange only occurs in the portion of the conduit 16 in which the
fins 26 and the second flow passage 24 are disposed.
[0038] FIG. 2 shows another exemplary heat exchanger. In this
example, both the fins 26 and the second flow passage 24 extend
around the entire circumference of the conduit 16. Hence, heat
exchange occurs around the entire circumference of the conduit
16.
[0039] FIG. 3 shows another exemplary heat exchanger. In this
example, second flow passage 24 extends around less than 50% of the
conduit 16. The heat exchanger comprises both heat exchange fins
26, which are disposed around the portion of the conduit 16 where
the second flow passage 24 is present, and non-exchange fins 28,
which are distributed around the remaining portion of the
circumference of the conduit 16. Heat exchange only occurs in the
portion of the conduit 16 where the second flow passage 24 is
disposed. The non-exchange fins 28 largely only act to guide flow
(as will be discussed below).
[0040] With reference to FIGS. 4A-C, there is shown an embodiment
of a heat exchanger consistent with FIG. 1. The embodiment of FIG.
1 is used only as an example, and the features described below
could similarly be present in any of the examples of FIG. 2 or
3.
[0041] FIG. 4A shows an oblique view of the heat exchanger of FIG.
1. The conduit 16 has an inlet 30 and an outlet 32, and is
generally of the form as discussed above in relation to FIGS.
1-3.
[0042] The fins 26 are angled relative to a longitudinal axis X of
the conduit 16 in order to direct and swirl the flow in the first
flow passage 22. The fins 26 form helical flowpaths 27 therebetween
in order to direct the flow. The flow in the first flow passage 22
is imparted with an angular momentum in order to `spin` outward
from the outlet 32 of the conduit 16 to an inlet of a downstream
matrix (not shown). By this mechanism, the flow is more evenly
distributed across an inlet of the matrix, particularly at the
points of the matrix inlet furthest from the centre of the outlet
32 of the conduit 16. Such an arrangement is illustrated
schematically in FIGS. 6 and 7, which show a swirled fluid flow
from a conduit 2 entering a matrix 4. The flow from the conduit 2
is imparted with an angular momentum by the fins of the heat
exchanger. By this mechanism, the flow is dispersed downstream to
an inlet 6 of the matrix 4.
[0043] The matrix could be for the purpose of heat exchange or
facilitating a chemical reaction. It is envisaged that the matrix
could form part of a heat exchanger or ozone converter for an
environmental control system of an aircraft.
[0044] As can be seen in FIGS. 4A-C, the fins 26 are straight along
their length. The fins 26 form an angle with the longitudinal axis
X at the outlet 32 of the conduit 30. This angle may be between
10.degree. and 45.degree.. In some examples, the angle may be
between 10.degree. and 20.degree..
[0045] FIGS. 5A-C show an exemplary heat exchanger. The heat
exchanger is similar to that of FIGS. 4A-C, but in this example
fins 26 are curved along their length. The fins 26 are straight at
the inlet 30 of the conduit 16, and curve to be angled at the
outlet 32. Again, the fins 26 form an angle with the longitudinal
axis X of the conduit 16 at the outlet 32. The angle may be the
same as that discussed in the above "straight-fin" embodiment.
[0046] In an example not shown in the figures, the fins 26 could be
corrugated along their length to provide increased heat-transfer
interaction with the flow in the first flow passage 22. The fins
would further be arranged to form a helical flowpath 27 in order to
swirl the flow, as discussed above.
[0047] Although not shown, non-exchange fins 28 could have the form
of either of the heat exchange fins 26 of FIG. 4A or 5A. These
non-exchange fins 28 would also serve to swirl the flow through the
first flow passage 22 as discussed above in relation to the heat
exchange fins 26.
[0048] In further embodiments, a second set of fins 25 may project
into the second flow passage 24. This would provide increased
interaction with the fluid flow in the second flow passage 24 to
improve heat exchange with a fluid therein. The second set of fins
25 may be aligned with the heat exchange fins 26, or be an
extension of the heat exchange fins 26 through the interior surface
18 of the conduit 16. Such an embodiment is illustrated
schematically by dotted lines in FIGS. 4C and 5C.
[0049] In an arrangement not shown, the fins of the second set of
fins 25 may be circumferentially offset from the first set of fins
26. For example, they may be positioned circumferentially between
the first fins.
[0050] In accordance with the present disclosure, therefore,
heat-exchanger fins can be arranged on the interior surface of a
conduit which supplies a fluid to a matrix. The fins are angled to
form a helical flowpath and thereby as a flow swirler. Hence, the
conduit can swirl flow for a downstream matrix and provide for
heat-exchange.
[0051] Although the figures and the accompanying description
describe particular embodiments and examples, it is to be
understood that the scope of this disclosure is not to be limited
to such specific embodiments, and is, instead, to be determined by
the following claims.
* * * * *