U.S. patent application number 15/672428 was filed with the patent office on 2018-02-15 for heat exchanger device.
The applicant listed for this patent is HS Marston Aerospace Limited. Invention is credited to Berwyn POLLARD.
Application Number | 20180045469 15/672428 |
Document ID | / |
Family ID | 60989384 |
Filed Date | 2018-02-15 |
United States Patent
Application |
20180045469 |
Kind Code |
A1 |
POLLARD; Berwyn |
February 15, 2018 |
HEAT EXCHANGER DEVICE
Abstract
A multilayer heat exchanger device a frame constructed of
multiple laminate layers that are bonded together. The device has a
first fluid inlet manifold and a first fluid outlet manifold for
connection to a supply and a return for the first fluid, the first
fluid inlet manifold and the first fluid outlet manifold extending
through the laminate layers of the frame; a second fluid inlet
manifold and a second fluid outlet manifold for connection to a
supply and a return for the second fluid, the second fluid inlet
manifold and the second fluid outlet manifold extending through the
laminate layers of the frame.
Inventors: |
POLLARD; Berwyn;
(Wolverhampton, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HS Marston Aerospace Limited |
Wolverhampton |
|
GB |
|
|
Family ID: |
60989384 |
Appl. No.: |
15/672428 |
Filed: |
August 9, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28D 2021/0021 20130101;
F28F 9/0221 20130101; F28F 9/001 20130101; F28D 9/02 20130101; F28D
9/0075 20130101 |
International
Class: |
F28D 9/00 20060101
F28D009/00; F28F 9/00 20060101 F28F009/00; F28F 9/02 20060101
F28F009/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 10, 2016 |
GB |
1613732.5 |
Claims
1. A multilayer heat exchanger device for heat exchange between at
least a first fluid and a second fluid, the device comprising: a
frame constructed of multiple laminate layers that are bonded
together; a first fluid inlet manifold and a first fluid outlet
manifold for connection to a supply and a return for the first
fluid, the first fluid inlet manifold and the first fluid outlet
manifold extending through the laminate layers of the frame; a
second fluid inlet manifold and a second fluid outlet manifold for
connection to a supply and a return for the second fluid, the
second fluid inlet manifold and the second fluid outlet manifold
extending through the laminate layers of the frame; a plurality of
first fluid flow paths for flow of the first fluid from the first
fluid inlet manifold to the first fluid outlet manifold; a
plurality of second fluid flow paths for flow of the second fluid
from the second fluid inlet manifold to the second fluid outlet
manifold; and a heat transfer region where the first fluid path and
the second fluid path are in heat exchange relationship such that,
in use, heat will be exchanged between the first fluid and the
second fluid; wherein the multiple laminate layers comprise
multiple first layers and multiple second layers in a repeating
arrangement; wherein each of the first layers includes a first
fluid flow path that passes through a cavity, the cavity being
located at the heat exchanger region and being for receiving heat
exchanger finstock, the cavity opening into the first fluid inlet
manifold and the first fluid outlet manifold and being closed to
the second fluid inlet manifold and the second fluid outlet
manifold; and wherein each of the second layers includes a second
fluid flow path that passes through a cavity, the cavity being
located at the heat exchanger region and being for receiving heat
exchanger finstock, the cavity opening into the second fluid inlet
manifold and the second fluid outlet manifold and being closed to
the first fluid inlet manifold and the first fluid outlet
manifold.
2. A multilayer heat exchanger device as claimed in claim 1,
wherein the inlet and outlet manifolds each pass through the layers
of the frame, which hence form all of or a part of the
manifolds.
3. A multilayer heat exchanger device as claimed in claim 1,
wherein the manifolds are located about the outside of the heat
exchange region, and hence about the outside of the cavities in the
layers, with each at a side of the cavities and the number of sides
of the cavities corresponding to the number of manifolds.
4. A multilayer heat exchanger device as claimed in claim 1,
wherein the cavities of the layers are open to the relevant inlet
and outlet manifolds via openings extending through the depth of
the layer and across the width of the manifold, and the cavities of
the layers are closed to the other inlet and outlet manifolds by
having no opening adjacent those manifolds.
5. A multilayer heat exchanger device as claimed in claim 1,
wherein the fluid flow paths for the different fluids are separated
by parting sheets.
6. A multilayer heat exchanger device as claimed in claim 5,
wherein the parting sheets are integrated with the layers.
7. A multilayer heat exchanger device as claimed in claim 5,
wherein the parting sheets are separate from both the layers and
the finstock.
8. A multilayer heat exchanger device as claimed in claim 1,
comprising finstock in the cavities, the finstock being separate to
the layers and held within the cavity of each layer.
9. A multilayer heat exchanger device as claimed in claim 8,
wherein the finstock has been formed by etching, stamping,
moulding, punching and/or cutting, such as laser cutting, EBM
cutting or EB cutting.
10. A multilayer heat exchanger device as claimed in claim 8,
wherein the manufacturing technique used for the finstock is
different to that used for the layers of the frame and/or the
finstock is manufactured from a different material than the
material(s) of the layers.
11. A multilayer heat exchanger device as claimed in claim 1,
wherein the frame layers are layers of a laminate structure that
provides all of or the majority of the structural strength for the
heat exchanger device.
12. A multilayer heat exchanger device as claimed in claim 1,
wherein the finstock is not exposed to structural loads.
13. A multilayer heat exchanger device as claimed in claim 1,
wherein the layers are be bonded together by brazing, diffusion
bonding, welding or adhesives.
14. A multilayer heat exchanger device as claimed in claim 1,
wherein there is no mechanical interconnection of the layers aside
from the bonding between the layers.
15. A multilayer heat exchanger device as claimed in claim 1,
wherein the layers are formed by etching, stamping, moulding,
punching, cutting, laser cutting, electron beam machining (EBM)
cutting or electron beam (EB) cutting.
16. A multilayer heat exchanger device as claimed in claim 1,
wherein the thickness of the each of the layers is less 5 mm,
optionally less than 1 mm.
17. A multilayer heat exchanger device as claimed in claim 1,
wherein the heat exchanger device includes at least 40 layers.
18. An aircraft including a multilayer heat exchanger device as
claimed in claim 1.
19. A method for manufacturing a multilayer heat exchanger device
for heat exchange between at least a first fluid and a second
fluid, the device comprising: a frame constructed of multiple
laminate layers; a first fluid inlet manifold and a first fluid
outlet manifold for connection to a supply and a return for the
first fluid, the first fluid inlet manifold and the first fluid
outlet manifold extending through the laminate layers of the frame;
a second fluid inlet manifold and a second fluid outlet manifold
for connection to a supply and a return for the second fluid, the
second fluid inlet manifold and the second fluid outlet manifold
extending through the laminate layers of the frame; a plurality of
first fluid flow paths for flow of the first fluid from the first
fluid inlet manifold to the first fluid outlet manifold; a
plurality of second fluid flow paths for flow of the second fluid
from the second fluid inlet manifold to the second fluid outlet
manifold; and a heat transfer region where the first fluid path and
the second fluid path are in heat exchange relationship such that,
in use, heat will be exchanged between the first fluid and the
second fluid; the method comprising: assembling the frame from the
multiple laminate layers using multiple first layers and multiple
second layers in a repeating arrangement; wherein each of the first
layers includes a first fluid flow path that passes through a
cavity located at the heat exchanger region, the cavity opening
into the first fluid inlet manifold and the first fluid outlet
manifold and being closed to the second fluid inlet manifold and
the second fluid outlet manifold; and wherein each of the second
layers includes a second fluid flow path that passes through a
cavity located at the heat exchanger region, the cavity opening
into the second fluid inlet manifold and the second fluid outlet
manifold and being closed to the first fluid inlet manifold and the
first fluid outlet manifold; wherein the assembling includes
inserting finstock in each of the cavities and bonding the multiple
laminate layers together to form the frame.
20. A method as claimed in claim 19, comprising providing features
of the heat exchanger device as claimed in claim 1.
Description
FOREIGN PRIORITY
[0001] This application claims priority to Great Britain Patent
Application No. 1613732.5 filed Aug. 10, 2016, the entire contents
of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The disclosure relates to a heat exchanger device and to a
method for manufacturing a heat exchanger device. In an example
implementation the heat exchanger device is for aerospace use.
BACKGROUND
[0003] Heat exchangers for transfer of heat between different
fluids are very widely used and exist in various forms. Typically
heat exchangers are arranged for flow of a primary fluid and a
secondary fluid with heat being transferred between the two fluids
as they flow through the device. Multi-stream heat exchangers for
exchanging heat between more than two fluids also exist in the
prior art. Some heat exchangers have a layered structure with a
large number of parallel flow paths between plates that separate
the flow paths. There may be 50-200 plates, or more, in this type
of heat exchanger, typically with alternating hot/cold fluid flow
paths either side of each plate.
[0004] US 2013/048261 discloses a laminate heat exchanger device
with multiple laminate layers formed with corrugations to promote
heat transfer. The laminates are stacked together and joined by
brazing, diffusion bonding and/or welding along the adjacent
surfaces of each pair of adjacent laminates. Jiggling features
outside of the heat exchanging area are used during assembly to
ensure that the various layers are aligned with each other. After
the stack of laminate layers has been formed then manifold
structures are attached to the outside of the stack for guiding
flow of fluids into and out of the stack. For example, in the case
of a two fluid system where heat is transferred between a primary
fluid and secondary fluid then the manifolds would include a
primary fluid inlet manifold, primary fluid outlet manifold, a
secondary fluid inlet manifold and a secondary fluid outlet
manifold. Thus, the heat exchanger device may be used for heat
exchange with at least two fluids. Further manifolds could be added
to allow for multi-stream arrangements with more than two
fluids.
[0005] U.S. Pat. No. 6,427,764 discloses a layered heat exchanger
where a frame has an integrated flow path for pressurised air,
which exchanges heat with exhaust gases that flow through the heat
exchanger via slots opening across each layer. The heat exchanger
is formed as a plate fin arrangement where a frame is formed from
the layers with corrugated flow guide plates between them, with the
corrugated flow guide plates promoting parallel flow of the air and
exhaust in opposite directions.
SUMMARY
[0006] Viewed from a first aspect, the invention provides a
multilayer heat exchanger device for heat exchange between at least
a first fluid and a second fluid, the device comprising: a frame
constructed of multiple laminate layers that are bonded together; a
first fluid inlet manifold and a first fluid outlet manifold for
connection to a supply and a return for the first fluid, the first
fluid inlet manifold and the first fluid outlet manifold extending
through the laminate layers of the frame; a second fluid inlet
manifold and a second fluid outlet manifold for connection to a
supply and a return for the second fluid, the second fluid inlet
manifold and the second fluid outlet manifold extending through the
laminate layers of the frame; a plurality of first fluid flow paths
for flow of the first fluid from the first fluid inlet manifold to
the first fluid outlet manifold; a plurality of second fluid flow
paths for flow of the second fluid from the second fluid inlet
manifold to the second fluid outlet manifold; and a heat transfer
region where the first fluid path and the second fluid path are in
heat exchange relationship such that, in use, heat will be
exchanged between the first fluid and the second fluid; wherein the
multiple laminate layers comprise multiple first layers and
multiple second layers in a repeating arrangement; wherein each of
the first layers includes a first fluid flow path that passes
through a cavity, the cavity being located at the heat exchanger
region and being for receiving heat exchanger finstock, the cavity
opening into the first fluid inlet manifold and the first fluid
outlet manifold and being closed to the second fluid inlet manifold
and the second fluid outlet manifold; and wherein each of the
second layers includes a second fluid flow path that passes through
a cavity, the cavity being located at the heat exchanger region and
being for receiving heat exchanger finstock, the cavity opening
into the second fluid inlet manifold and the second fluid outlet
manifold and being closed to the first fluid inlet manifold and the
first fluid outlet manifold.
[0007] This arrangement uses a layered frame structure with
integrated manifolds for all of the fluid flow paths within the
heat exchanger, whilst also allowing finstock of any required type
to be held between the layers. Thus, the invention provides a
hybrid arrangement that can combine the advantages of laminated
type finstock, such as the complicated shapes available from
layering etched layers to form the finstock, without the
disadvantages that arise in relation to the attachment of manifolds
to the exterior of laminated finstock. The layers of the heat
exchanger frame are bonded together and as discussed below this may
provide the structural strength for the heat exchanger, with there
hence being no significant mechanical load on the finstock. This
means that the finstock can advantageously have a material and
construction that is optimised for maximum heat transfer, rather
than needing to have structural properties as is the case in some
prior art devices. The finstock could optionally be bonded to the
frame layers, but this is not required and in some examples the
finstock is simply held captive by the geometry of the cavity
formed within the frame layers. The latter feature removes further
constraints on the material and construction of the finstock, since
it no longer needs to be capable of being joined to the material of
the frame.
[0008] A multilayer heat exchanger device of the type set out in
the first aspect has many layers with multiple fluid flow paths
being arranged for heat exchange with adjacent fluid flow paths.
The fluid flow paths may all be in parallel planes, and may have
parallel flow paths with the same or different directions of flow,
such as opposite flow directions or cross-flow. Thus, the layers
may be generally planar in order that adjacent layers enclose a
fluid flow path with the principle flow direction being parallel
with the planes of the adjacent layers. A typical heat exchanger
device has primary and secondary fluids flowing in parallel layers
in different directions, which maximises the temperature
differential between the fluids and thus gives the greatest rate of
heat transfer.
[0009] The inlet and outlet manifolds each pass through the layers
of the frame. The assembly of layers may hence form all of or a
part of the manifolds, for example via a sequence of aligned
throughholes in each layer. Thus, each layer may have a through
hole for each manifold. In some examples the manifolds are located
about the outside of the heat exchange region, and hence about the
outside of the cavities in the layers. Each manifold may be at a
side of the cavity with the number of sides corresponding to the
number of manifolds. For example, in the case of only two fluids
then there are four manifolds in total and these manifolds may be
placed about four sides of the cavities, for example about four
sides of a rectangular area such as a square. In that case the
first fluid inlet and outlet may be at two opposite sides and the
second fluid inlet and outlet may be at the other two opposite
sides. The fluid flow paths may pass straight across the cavities
in a cross-flow heat exchanger arrangement. Finstock may be
provided in the cavities as discussed in further detail below in
order to improve the heat transfer.
[0010] The manifolds may also provide jiggling features for use in
assembly of the layers of the frame, or alternatively/additionally
the layers may have separate jiggling features formed therein. The
layers may also include throughholes for housing additional
components of the heat exchanger device, such as valves, pumps,
sensors and so on. In one example the layers have throughholes that
align to form a valve housing when the layers are stacked
together.
[0011] Whilst the use of two fluids in a heat exchanger is most
commonplace, heat exchanger device such as that of the first aspect
may be multistream heat exchangers with heat exchange between more
than two fluids, for example three, or four, or more than four
fluids. In that case the heat exchanger device may be provided with
additional manifolds and fluid flow paths and thus there may be
further layer types such as multiple third layers in addition to
the multiple first layers and second layers.
[0012] The cavities of the layers may be open to the relevant inlet
and outlet manifolds via openings extending through the depth of
the layer and across the width of the manifold, which may hence
form a slotted opening between the cavity and the manifold. The
cavities of the layers may be closed to the other inlet and outlet
manifolds by having no opening adjacent those manifolds, for
example by the use of enclosure bars extending across the width of
those manifolds. In the case of a two fluid heat exchanger device
such one using the four sided arrangement described above then in
the first layers the openings are along the two sides of the
cavities that face the first fluid inlet manifold and first fluid
outlet manifold whereas enclosure bars are along the two sides of
the cavities that face the second fluid inlet manifold and second
fluid outlet manifold, and in the second layers the openings are
along the two sides of the cavities that face the second fluid
inlet manifold and second fluid outlet manifold whereas enclosure
bars are along the two sides of the cavities that face the first
fluid inlet manifold and first fluid outlet manifold.
[0013] If a rectangular shape is used for the cavities then the
heat exchanger region may extend over a cuboid volume with the
manifolds formed outside of this cuboid region. The openings from
the first layer cavities into the first fluid inlet manifold and
first fluid outlet manifold may take the form a sequence of slotted
gaps of the first layers in between the enclosure bars of the
second layers, and openings from the second layer cavities into the
second fluid inlet manifold and second fluid outlet manifold may
take the form of a sequence of slotted gaps of the second layers in
between the enclosure bars of the first layers.
[0014] The repeating arrangement for the layers may consist of an
alternating sequence of each layer, for example alternating first
and second layers where there are two layer types, or a repeated
sequence of first layer, second layer and then third layer. More
complicated layering arrangements may also be used, for example
where one layer is present in pairs, such as by having one first
layer, the two second layers, then another first layer and so on.
This can be useful to allow for a greater flow volume and/or lower
pressure drop for one fluid compared to another. Another way to
vary the flow volume and/or pressure drop is for the first layers
to have a different thickness than the second layers.
[0015] The layers include cavities for holding finstock, with the
cavities being part of, or optionally the entirety of, the fluid
flow paths from the inlet manifold to the outlet manifold. The
fluid flow paths for the different fluids are separated and this
may be done via parting sheets between the fluid flow paths. The
parting sheets may be integrated with the layers or alternatively
they may be integrated with the finstock and received in the cavity
along with the finstock. In a further alternative the parting
sheets may be separate from both the layers and the finstock. For
example they may be separate sheets that are fitted to the layers
along with the finstock. In the examples where the parting sheets
are not integrated with the layers then they may be bonded to the
layers, for example by brazing, diffusion bonding or adhesive.
[0016] The device may include finstock in the cavities. In
particular there may be finstock that is separate to the layers,
the finstock being held within the cavity of each layer. The
finstock may be bonded to the layer, for example by brazing,
diffusion bonding, welding or adhesive. This means that the
finstock is securely fixed to the cavity and can increase the ease
of handling of the layers with the finstock prior to assembly of
the frame. However it can be an advantage for ease of manufacture
of the device if the finstock is held within the cavity without
bonding, for example it may be held securely by closed sides of the
cavity and/or by tabs or lips at the open side of the cavity. In
that instance the finstock and layers can be assembled very quickly
by laying the various parts upon on another, optionally with the
addition of separate parting sheets. In addition, since the
finstock is not bonded to the layers then differences in thermal
expansion of the finstock and the layers can be more readily
accommodated without the generation of excessive stresses in the
material of the finstock and/or layers of the frame.
[0017] The finstock may be formed by etching, stamping, moulding,
punching and/or cutting, such as laser cutting, electron beam
machining (EBM) cutting or electron beam (EB) cutting. The
manufacturing technique used for the finstock can be different to
that used for the layers of the frame. The finstock may include
fins such as pin fins or any other known type of heat exchanger
fins.
[0018] The frame layers are layers of a laminate structure that
advantageously provides both guidance of fluid flows as well as
structural strength. The laminated structure of the frame may
provide the majority of the structural strength for the heat
exchanger device, and the finstock may not be exposed to structural
loads. The layers may be bonded together by any suitable technique
taking account of the material of the layers and the operating
conditions of the heat exchanger device. For example the layers may
be bonded by brazing, diffusion bonding, welding or adhesives. In
example embodiments there is no mechanical interconnection of the
layers, i.e. there are no mechanical joins that clamp the layers or
otherwise hold them together. One embodiment uses brazing to join
the layers with each layer being provided with a suitable braze
sheet prior to assembly along with the finstock, and the stack of
layers being heated whilst being held together in order to form the
brazed connections between the layers and complete the laminate
structure of the frame.
[0019] The layers may be formed by etching, stamping, moulding,
punching and/or cutting, such as laser cutting, EBM cutting or EB
cutting. In some examples etching is used, optionally in
conjunction with other techniques. Etching allows for accurate
formation of shim type layers with low thicknesses and no unwanted
deformation to the layers from the manufacturing process. This can
provide a way to make a heat exchanger device with a high number of
thin layers, which has advantages in relation to the heat transfer
between the fluid flow paths, since a larger number of first and
second fluid flow paths can be provided in a heat exchanger device
of given size.
[0020] The thickness of the each of the layers may be less than 5
mm, optionally less than 1 mm. The heat exchanger device with a
hybrid construction as described herein has particular advantages
for laminated arrangements having many layers with low
thickness.
[0021] As noted above, the use of separate finstock provides
advantages in relation to the flexibility of choice of material and
form for the finstock. Any fin arrangement may be used with this
being selected with consideration of the heat exchange that is
required, for example the nature of the fluid and the temperature
of the fluid. The finstock may be manufactured from a different
material than the layer and/or from a different material to the
parting sheet. Different finstock may be used for each of the
different types of layers, and thus there may be a first type of
finstock held in the cavities of the first layers and a second type
of finstock held within the cavities of the second layers, as well
as optionally third and further types of finstocks for multistream
heat exchangers.
[0022] The heat exchanger device may be for use with any required
combination of fluids, such as liquid-liquid, liquid-gas or gas-gas
heat exchange. Advantageously, by providing a laminated layered
frame arrangement it becomes possible to easily handle a range of
fluid types, temperatures and pressures. The geometry of the frame
layers and/or the material(s) of the frame layers can be selected
to suit the fluid characteristics, and the material can differ from
the material of the heat exchanger finstock held by the frame.
There is no need for a direct fluid-tight connection between the
finstock and the frame, which further increases the degree of
freedom in selection of materials. The proposed hybrid arrangement
hence gives a wider range of possible applications. The heat
exchanger may use air for heating or cooling of another fluid. In
some examples the heat exchanger is for aerospace use and the
invention thus extends to an aircraft including the heat exchanger
device. In context of aerospace use the fluids could include two or
more of: atmospheric air, cabin air, engine oil, generator oil,
coolant, fuel and so on.
[0023] The material of the finstock and/or of the layers may be
selected bearing in mind the intended use of the device and
limitations arising from the temperatures and fluids involved in
the use of the device. In particular, in some cases the material
may be selected to withstand high or low temperatures, or to be
resistant to potentially chemically reactive fluids such as fuel or
coolant. The finstock and/or the layers may comprise aluminium and
may be an aluminium alloy. Alternatively stainless steels or copper
based materials may be used. It will be appreciated that metals
such as aluminium can be readily etched, and that they provide a
high conductance of heat. Non-metallic materials may also be
possible, such as ceramic or plastic materials. As noted above the
construction of the proposed device means that differing materials
may be used for the finstock compared to for the layers. It is also
possible to use different materials for the layers and/or finstock
associated with the first fluid compared to the material used for
the layers and/or finstock associated with the second fluid.
Similarly, if third and optionally further fluids are used then the
materials that are used could be different again.
[0024] The heat exchanger device is a multilayer structure with
many layers, generally arranged in a repeating pattern in respect
to the flow of fluids. There may for example be at least 40 layers,
optionally at least 60 layers and in some cases 100 or more layers.
The size and flow capacity of the heat exchanger device increases
with the addition of more layers, which adds more flow paths, and
thus layers may be added as required to provide the necessary
performance. The thickness of the heat exchanger device as a whole
is set by the layer thickness and the number of layers.
[0025] Viewed from a second aspect, the invention provides a method
for manufacturing a multilayer heat exchanger device for heat
exchange between at least a first fluid and a second fluid, the
device comprising: a frame constructed of multiple laminate layers;
a first fluid inlet manifold and a first fluid outlet manifold for
connection to a supply and a return for the first fluid, the first
fluid inlet manifold and the first fluid outlet manifold extending
through the laminate layers of the frame; a second fluid inlet
manifold and a second fluid outlet manifold for connection to a
supply and a return for the second fluid, the second fluid inlet
manifold and the second fluid outlet manifold extending through the
laminate layers of the frame; a plurality of first fluid flow paths
for flow of the first fluid from the first fluid inlet manifold to
the first fluid outlet manifold; a plurality of second fluid flow
paths for flow of the second fluid from the second fluid inlet
manifold to the second fluid outlet manifold; and a heat transfer
region where the first fluid path and the second fluid path are in
heat exchange relationship such that, in use, heat will be
exchanged between the first fluid and the second fluid; the method
comprising: assembling the frame from the multiple laminate layers
using multiple first layers and multiple second layers in a
repeating arrangement; wherein each of the first layers includes a
first fluid flow path that passes through a cavity located at the
heat exchanger region, the cavity opening into the first fluid
inlet manifold and the first fluid outlet manifold and being closed
to the second fluid inlet manifold and the second fluid outlet
manifold; and wherein each of the second layers includes a second
fluid flow path that passes through a cavity located at the heat
exchanger region, the cavity opening into the second fluid inlet
manifold and the second fluid outlet manifold and being closed to
the first fluid inlet manifold and the first fluid outlet manifold;
wherein the assembling includes inserting finstock in each of the
cavities and bonding the multiple laminate layers together to form
the frame.
[0026] This method allows for effective manufacture of the heat
exchanger device of the first aspect, and provides similar
advantages. The method may include providing any of the features of
the heat exchanger set out above.
[0027] The method may include forming all of or a part of the
manifolds during assembly of the layers, for example via aligning a
sequence of throughholes, with the throughholes being provided in
some layers or optionally in all layers. The arrangement of the
manifolds may be as discussed above.
[0028] The method may include using the manifold throughholes as
jiggling features, or alternatively using dedicated jiggling
feature for jiggling in order to align the layers of the frame
prior to bonding them together.
[0029] In some examples the method includes forming the layers, and
hence may comprise forming the each of the layers with the
throughholes and cavity. The cavities may be open to the relevant
inlet and outlet manifolds via openings extending through the depth
of the layer and across the width of the manifold, which may hence
form a slotted opening between the cavity and the manifold. The
cavities may be closed to the other inlet and outlet manifolds by
having no opening adjacent those manifolds, for example by forming
the cavity with enclosure bars extending across the width of those
manifolds. The layers and features of the layers such as the cavity
may be as described above. The layers may be formed by etching,
stamping, moulding, punching and/or cutting, such as laser cutting,
EBM cutting or EB cutting. In some examples etching is used,
optionally in conjunction with other techniques.
[0030] The layers may be bonded together by any suitable technique
taking account of the material of the layers and the operating
conditions of the heat exchanger device. For example the layers may
be bonded by brazing, diffusion bonding, welding or adhesives. In
example embodiments the method does not include using any
mechanical interconnection of the layers in the final frame, i.e.
there are no mechanical joins that clamp the layers or otherwise
hold them together. One embodiment uses brazing to join the layers
with each layer being provided with a suitable braze sheet prior to
assembly along with the finstock, and the stack of layers being
heated whilst being held together in order to form the brazed
connections between the layers and complete the laminate structure
of the frame.
[0031] The method includes assembling the frame with a repeating
arrangement for the layers. This may consist of an alternating
sequence of each layer, for example alternating first and second
layers where there are two layer types, or a repeated sequence of
first layer, second layer and then third layer. More complicated
layering arrangements may also be used, as discussed above.
[0032] The fluid flow paths for the different fluids are separated
and the method may include assembling the layers with parting
sheets between the fluid flow paths. As discussed above the parting
sheets may be integrated with the layers or alternatively they may
be integrated with the finstock and received in the cavity along
with the finstock, and in a further alternative the parting sheets
may be separate from both the layers and the finstock.
[0033] The finstock may be separate to the layers, the finstock
being held within the cavity of each layer. The finstock may be
bonded to the layer, for example by brazing, diffusion bonding,
welding or adhesive. Alternatively, the finstock may be held within
the cavity without bonding, for example it may be held securely by
closed sides of the cavity and/or by tabs or lips at the open side
of the cavity. In that instance the method may comprise layering
the finstock and layers upon on another without bonding them
together, optionally with the addition of separate parting
sheets.
[0034] The method may include forming the finstock, for example by
etching, stamping, moulding, punching and/or cutting, such as laser
cutting, EBM cutting or EB cutting. The manufacturing technique
used for the finstock can be different to that used for the layers
of the frame.
[0035] As noted above, the use of separate finstock provides
advantages in relation to the flexibility of choice of material and
form for the finstock. Different types of finstock may be used for
the different layers as discussed above. The method may include
selecting the geometry of the frame layers and/or the material(s)
of the frame layers to suit the characteristics of the fluid that
the heat exchanger device will be used with. The method may include
selecting the material of the finstock and/or of the layers bearing
in mind the intended use of the device and limitations arising from
the temperatures and fluids involved in the use of the device.
[0036] In some examples the heat exchanger is for aerospace use and
the invention thus extends to a method including installation of
the heat exchanger on an aircraft and/or the steps relating to
selecting the materials and so on may include selecting materials
for aerospace use.
BRIEF DESCRIPTION OF THE FIGURES
[0037] Preferred embodiments of the invention are described below
by way of example only and with reference to the accompanying
drawings, in which.
[0038] FIG. 1 shows a repeating cell of a layered heat exchanger
device; and
[0039] FIG. 2 shows an exploded view of the cell of FIG. 1.
DETAILED DESCRIPTION
[0040] In an embodiment a heat exchanger device is assembled using
multiple cells as shown in FIG. 1 and FIG. 2. Each cell is made up
of a first layer 12 and a second layer 14. The heat exchanger
device would have many such cells and hence a repeated arrangement
of first layers 12 and second layers 14 in alternating sequence.
The first layer 12 is for a first fluid and the second layer 14 is
for a second fluid, with the heat exchanger device being for heat
exchange between the first and second fluids in a heat exchange
region.
[0041] The heat exchanger device includes finstock 16 in fluid flow
paths that pass through the heat exchange region. The first and
second layers 12, 14 include throughholes that are located about
the outside of the heat exchange region and align together to form
manifolds for connection to supply and return for the first fluid
and the second fluid. In this example there are four manifolds,
being a first fluid inlet manifold 18 and a first fluid outlet
manifold 20 for connection to a supply and a return for the first
fluid, along with a second fluid inlet manifold 22 and a second
fluid outlet manifold 24 for connection to a supply and a return
for the second fluid. It will be appreciated that the location of
the inlet and outlet manifolds could be reversed compare to how
they are shown in the Figures.
[0042] The first layer 12 has a cavity 26 that is open to the first
fluid inlet manifold 18 and the first fluid outlet manifold 20,
with enclosure bars 28 closing the cavity 26 from the second fluid
inlet manifold 22 and the second fluid outlet manifold 24. When the
device is assembled then finstock 16 is inserted into the cavity 26
of the first layer and the first fluid can flow through the
finstock 16 between the first fluid inlet manifold 18 and the first
fluid outlet manifold 20. The second layer 14 has a similar cavity
(not shown) that is open to the second fluid inlet manifold 22 and
the second fluid outlet manifold 24, with enclosure bars 28 closing
the cavity from the first fluid inlet manifold 18 and the first
fluid outlet manifold 20. Again, when the device is assembled then
finstock 16 is inserted into the cavity of the second layer and the
second fluid can flow through the finstock 16 between the second
fluid inlet manifold 22 and the second fluid outlet manifold 24. It
will be appreciated that with a stack of cells of the type shown in
FIG. 1 then when fluid connections for supply and return of the
first and second fluids are made with the manifolds 18, 20, 22, 24
then the first and second fluid will flow simultaneously through
many parallel paths, with heat being exchanged along the extent of
the stack of cells at the heat exchange region.
[0043] In this example the layers 12, 14 include integrated parting
sheets 26, which act to separate the fluid flow paths. The parting
sheets 26 could alternatively be separate parts, such as separate
sheets that are assembled with the layers 12, 14 along with the
finstock 16. The finstock 16 can be corrugated finstock 16 as shown
in the Figures, for example etched shim finstock. Other types of
finstock 16 could be used if required. The layers 12, 14 may be
manufactured by etching, which allows for relatively thin layers to
be formed. In addition to the throughholes used to form the
manifolds 18, 20, 22, 24 the layers 12, 14 further include jiggling
features 30 for use in alignment of the layers 12, 14 before they
are bonded together. The layers 12, 14 can also include other
features, such as holes 32 for forming valve housings or the
like.
[0044] Although the present disclosure has been described with
reference to particular embodiments, the skilled reader will
appreciate that modifications may be made that fall within the
scope of the disclosure as defined by the appended claims. For
example, there may be more than two fluids involved and thus there
may be a third layer for a third fluid and an alternative
configuration for all layers in order to allow for an additional
inlet and outlet manifold. In addition, many modifications may be
made to adapt a particular situation or material to the teachings
of the present disclosure without departing from the essential
scope thereof. Therefore, it is intended that the present
disclosure not be limited to the particular embodiment disclosed as
the best mode contemplated for carrying out this present
disclosure, but that the present disclosure will include all
embodiments falling within the scope of the claims.
[0045] The term "about" is intended to include the degree of error
associated with measurement of the particular quantity based upon
the equipment available at the time of filing the application.
[0046] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the present disclosure. As used herein, the singular forms "a",
"an" and "the" are intended to include the plural forms as well,
unless the context clearly indicates otherwise. It will be further
understood that the terms "comprises" and/or "comprising," when
used in this specification, specify the presence of stated
features, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other
features, integers, steps, operations, element components, and/or
groups thereof.
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