BACKGROUND
[0001] Heat exchangers are used to transfer heat between fluids in various technological
areas. Typical heat exchangers include a stack of plates with fluid passing between
them. In many heat exchangers, the layers alternate between hot and cold, and stacks
of 50 or more layers are used to efficiently transfer heat. These stacked layers maximize
the so-called "first surface" surface area, which is the surface area of the plates
across which heat may conductively pass.
[0002] In some heat exchangers, pins, fins, posts, or ridges are employed to increase the
surface area through which heat is transferred. Protrusions from the first surface,
such as pins, fins, and posts, form so-called "second surfaces". Second surfaces are
often generated by etching a relatively thick plate, while leaving the second surface
protrusions un-etched. These second surfaces not only facilitate heat transfer between
the first surface and the fluid, but also may be used to reinforce the stack and maintain
a desired distance between adjacent heat exchange plates in the stack.
[0003] Another type of heat exchange plate defines ridges, as opposed to protrusions. This
type of heat exchange plate is advantageous because it may be stamped out of a single
piece of material, without requiring etching, reducing cost and complexity. One commonly
used ridge pattern is a herringbone pattern, in which a large number of nested V-shaped
ridges are stamped into the plate. The Vs of alternating plates are typically oriented
in opposite directions. Thus, any two adjacent plates will touch each other at each
location where the ridges of the bottom plate are at a peak and the ridges of the
top plate are at a trough. These locations approximate a grid of contact points, which
results in good reinforcement of the stack. The plates are kept at a desired distance
from one another by brazing each adjacent pair of plates at the grid of contact points.
[0004] As heat exchangers have been incorporated into aerospace technology, size and weight
have become greater concerns. Thus, heat exchanger plates have generally become thinner,
more lightweight, and more compact. Aerospace heat exchangers are often exposed to
high temperature differential, high flow rate and high pressure working fluids. These
goals must be accomplished without sacrificing heat exchange performance or structural
integrity of the heat exchanger. One problem introduced by the thinning of the heat
exchanger plates is that the corners of the heat exchangers may not have sufficient
structural integrity, and may bow outwards. Such bowing is undesirable for many reasons,
such as the potential for intermixing of the working fluids or other failures related
to rupture of the heat exchange plates at the corners.
SUMMARY
[0005] A heat exchanger is disclosed. The plates of the heat exchanger have structures thereon
at each of the fluid bypass apertures, fluid ingress apertures, and fluid egress apertures.
A heat exchanger plate has a heat transfer portion with a plurality of ribs arranged
in a rib pattern. The heat exchanger also has a fluid ingress structure arranged near
a first corner of the heat exchanger plate. The structure has a first open fluid aperture
defined in the heat exchanger plate, and a first platform arranged between the first
open fluid aperture and the first corner, wherein the first platform is connected
to a rib of the rib pattern. A fluid bypass structure near a second corner, the structure
including a closed fluid aperture defined in the heat exchanger plate, a second platform
completely surrounding the closed fluid aperture, and a first corner rib arranged
between the second platform and the second corner, wherein the first corner rib is
connected to a rib of the rib pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006]
Fig. 1 is an exploded view of two heat exchanger plates in stacked configuration.
Fig. 2a is a plan view of the fluid ingress structure of a heat exchanger plate.
Fig. 2b is a plan view of the fluid bypass structure of a heat exchanger plate.
DETAILED DESCRIPTION
[0007] The heat exchanger plates described herein prevent corner deformation of the heat
exchanger plates. Bypass apertures in the heat exchanger plate are reinforced with
a corner rib, which is tied into the main herringbone pattern of the heat exchange
plate. Ingress/egress apertures are also supported, first by moving the corner platform
inwardly towards the apertures, and second by tying the corner platform into the main
herringbone pattern of the heat exchanger plate. All of these changes combine to reduce
the size of unsupported corner tangencies.
[0008] Fig. 1 is an exploded view of two heat exchanger plates in stacked configuration.
Heat exchanger plate pair 8 includes upper heat exchange plate 10a and lower heat
exchange plate 10b, which are included as part of a much larger stack of heat exchanger
plates (not shown in this view). For example, heat exchanger plate pair 8 may be a
part of a heat exchanger stack having more than 50 heat exchange plates similar to
upper heat exchange plate 10a and lower heat exchange plate 10b. Often, these plates
will be arranged in alternating fashion; for example, a complete heat exchanger stack
could be constructed by stacking copies of heat exchanger plate pair 8 one on top
of the other to reach the desired stack height, and adding appropriate end caps (not
shown) on the top and bottom of the stack.
[0009] Upper heat exchange plate 10a includes upper plate herringbone ridge pattern 12a,
fluid ingress structure 14a, fluid egress structure 16a, and fluid bypass structures
18a. Lower heat exchange plate 10b includes lower plate herringbone ridge pattern
12b, fluid ingress structure 14b, fluid egress structure 16b, and fluid bypass structures
18b.
[0010] In the embodiment shown in Fig. 1, upper heat exchange plate 10a is a stamped metal
plate. By selecting a desired stamp or pattern, various contours may be impressed
into upper heat exchange plate 10a. In aerospace applications, heat exchange plates,
such as upper heat exchange plate 10a, are thinner than those used in industrial heat
exchange applications. As shown in Fig. 1, upper heat exchange plate 10a includes
upper plate herringbone rib pattern 12a, which includes a group of V-shaped ribs,
the point of each V facing towards the right-hand side of the page.
[0011] Upper heat exchange plate 10a defines four structures for handling fluids incident
thereon. Fluid ingress structure 14a is one of a series of structures that transmits
and selectively admits a fluid to cavities between select pairs of adjacent heat exchange
plates. Fluid egress structure 16a is one of a series of structures that takes up
fluid admitted to the cavities between those select pairs of adjacent heat exchange
plates by fluid ingress structure 14a. Hot fluid provided at fluid ingress structure
14a is communicated via the cavity formed between the select pairs of adjacent heat
exchange plates (such as upper heat exchange plate 10a and lower heat exchange plate
10b) and exits via fluid egress structure 16a. Fluid bypass structures 18a are capable
of transferring a second fluid, but prevents the second fluid from being admitted
to the same cavities that receive the first fluid. Fluid passing through fluid bypass
structures 18a may be in fluid communication with fluid ingress and egress structures
in other plates within a stack containing upper heat exchange plate 10a. In one embodiment,
the first fluid is a hot fluid and the second fluid is a relatively cold fluid.
[0012] Lower heat exchange plate 10b also defines four structures for handling fluids incident
thereon. Fluid ingress structure 14b is one of a series of structures that transmits
and selectively admits a second, relatively colder fluid to cavities defined between
a second select set of pairs of adjacent heat exchange plates. Fluid egress structure
16b is one of a series of structures that transmits the second, relatively cold fluid,
and takes up fluid admitted to the cavities between pairs of adjacent heat exchange
plates by fluid ingress structure 14b. Relatively colder fluid provided at fluid ingress
structure 14b is communicated via the cavities formed between the second select pair
of adjacent heat exchange plates, and exits via fluid egress structure 16b. Fluid
bypass structures 18b are capable of transferring the first, relatively hot fluid.
Fluid passing through fluid bypass structures 18b may be in fluid communication with
fluid ingress and egress structures in other plates within a stack containing lower
heat exchange plate 10b. For example, hot fluid passing through fluid bypass structures
18b may be in fluid communication with fluid ingress structure 14a and fluid egress
structure 16a.
[0013] In operation, lower heat exchange plate 10b is in contact with upper heat exchange
plate 10a to define a cavity therebetween. Often, lower heat exchange plate 10b and
upper heat exchange plate 10a are brazed together. Due to the opposite directions
of upper plate herringbone pattern 12a and lower plate herringbone pattern 12b, the
points of contact, at which brazing may occur, approximates a grid. Around these braze
contact points, a first fluid (e.g. a cool fluid) may flow unconstructed from fluid
ingress structure 14b to fluid egress structure 16b. Likewise, the flow of hot fluid
admitted by fluid ingress structure 14a is constrained to a cavity defined by a surface
of upper heat exchange plate 10a and a face of an adjacent heat exchange plate (not
shown) arranged thereon. Hot fluid that is routed through this cavity may exit via
fluid egress structure 16a.
[0014] Heat exchanger pair 8 is part of a larger heat exchanger that transfers heat between
two fluids without intermixing those fluids. Thus, it is desirable to have the relatively
cold fluid pass to heat exchange plates adjacent to upper heat exchange plate 10a,
without mixing with fluid from fluid ingress structure 14a. Thus, fluid bypass structures
18a are included to allow relatively colder fluid to pass by upper heat exchange plate
10a to one or more other heat exchange plates, such as lower heat exchange plate 10b.
Likewise, it is desirable to have the relatively hot fluid pass to heat exchange plates
adjacent to lower heat exchange plate 10b, without mixing with fluid from fluid ingress
structure 14b. Fluid bypass structures 18b are included to allow relatively hot fluid
to pass by lower heat exchange plate 10b to one or more other heat exchange plates,
such as upper heat exchange plate 10a.
[0015] The embodiment shown in Fig. 1 has structural enhancements on fluid ingress structure
14a, fluid egress structure 16a, and fluid bypass structures 18a. These structural
enhancements, which will be described in more detail with respect to Fig. 2, prevent
deformation and/or failure of the heat exchanger, in particular at the corners of
the plates, which is more prone to failure than most other parts of the heat exchanger.
[0016] Fig. 2a shows fluid ingress structure 14b of Fig. 1. Fluid ingress structure 14b
includes ingress aperture 20, ingress platform 22, and ingress corner space 24.
[0017] Lower heat exchange plate 10b is used to transfer heat between relatively hot and
cold fluids. Thus, as referred to with respect to Figs. 2a-2b, lower heat exchange
plate 10b defines the lower boundary of a first cavity, between lower heat exchange
plate 10b and upper heat exchange plate 10a, as well as a second cavity, between lower
heat exchange plate 10b and another heat exchange plate (not shown) positioned underneath
lower heat exchange plate 10b with respect to the orientation shown in Fig. 1. Lower
heat exchange plate 10b also has edges 11b, which are the portions of lower heat exchange
plate 10b which do not define any part of the cavities referred to previously, at
the top and left with respect to the orientation shown in Fig. 2a. Edges 11b may have
any variety of structures to prevent fluid from escaping the stack of heat exchange
plates, none of which are shown.
[0018] Ingress aperture 20 is positioned nearby one of the corners of lower heat exchange
plate 10b. Ingress aperture 20 is an aperture defined by heat exchange plate 10b,
and fluid passing through ingress aperture 20 is in fluid communication with a series
of other ingress apertures in other plates of the heat exchange stack, as well as
a series of fluid bypass structures. Ingress platform 22 is a long rib that extends
to at least partially surround ingress aperture 20, and connects to ribs of lower
plate herringbone pattern 12b at each of its ends. Ingress platform 22 may have different
dimensions than the ribs of lower plate herringbone pattern 12b. For example, ingress
platform 22 may be wider than the ribs of lower plate herringbone pattern 12b, and,
as shown, may be curved to follow the contours of ingress aperture 20 and/or edge
11b of lower heat exchange plate 10b.
[0019] Ingress corner space 24 is defined between edge 11b of lower heat exchange plate
10b and ingress platform 22. Ingress platform 22 is located approximately halfway
between ingress aperture 20 and edge 11b of lower heat exchanger plate 10b, such that
the distance from ingress aperture 20 to ingress platform 22 is approximately equal
to the distance from ingress platform 22 to edge 11b of lower heat exchange plate
10b. In alternative embodiments, the ratio of these two distances may be between 0.5
and 2.0.
[0020] Fluid passing through ingress aperture 20 also passes through the cavity defined
by lower heat exchange plate 10b and upper heat exchange plate 10a, as described previously
with respect to Fig. 1. Fluid that enters the cavity between lower heat exchange plate
10b and upper heat exchange plate 10a first passes through ingress aperture 20, then
flows across lower plate herringbone pattern 12b before being taken up by fluid egress
structure 16b (Fig. 1).
[0021] The proximity of ingress platform 22 to ingress aperture 20 minimizes the amount
of space on either side of ingress platform 22 that is unsupported by a rib and/or
platform. Additionally, tying inlet platform 22 to lower plate herringbone pattern
12b adds structural support to inlet platform 22. These structures in the orientation
illustrated in Fig. 2a give the corners of lower plate 10b substantial support to
oppose deformation.
[0022] A similar configuration is present at fluid egress structure 16b. Those skilled in
the art will readily appreciate that the same modifications may be made at fluid egress
structure 16b, including the positioning of an egress platform between an egress aperture
and edge 11b of lower heat exchange plate 10b to minimize the extent of unsupported
space, as well as tying such egress platform to lower plate herringbone pattern 12b.
The same benefits accrue at the corner adjacent fluid egress structure 16b due to
these modifications.
[0023] Fig. 2b is a plan view of fluid bypass structure 18b of lower heat exchange plate
10b, illustrating bypass aperture 26, bypass platform 28, and bypass rib 30.
[0024] Bypass aperture 26 is positioned near a corner of edge 11b of lower heat exchange
plate 10b. Bypass platform 28 completely surrounds bypass aperture 26. Bypass platform
28 is configured to prevent fluid communication between fluid flowing within bypass
aperture 26 and the cavity defined by lower heat exchange plate 10b and upper heat
exchange plate 10a, as described in more detail with respect to Fig. 1. As shown in
Fig. 1, bypass platform 28 is a raised pedestal that sits in contact with the bottom
surface of fluid ingress structure 14a. Thus, hot fluid may be routed to fluid ingress
structure 14a of Fig. 1, passing through lower heat exchange plate 10b without intermixing
with the cold fluid that passes through the cavity defined by lower heat exchange
plate 10b and upper heat exchange plate 10a.
[0025] Bypass rib 30 is positioned between edge 11b of lower heat exchange plate 10b and
bypass platform 28. Bypass rib 30 is unlike the ribs of lower plate herringbone pattern
12b in that it has a curved shape and follows the contours of bypass platform 28 and/or
edge 11b of lower heat exchange plate 10b. Bypass rib 30 is connected at each of its
ends to a rib that is a part of lower plate herringbone pattern 12b. Bypass rib bisects
the region between bypass platform 28 and a corner of edge 11b. In doing so, the corner
area gains significant structural support, and is less likely to suffer from deformation
and/or failure due to the pressure and temperature of the fluids incident thereon.
[0026] Analogous features are present at each additional bypass structure in the heat exchange
stack, including the second fluid bypass structure 18a as shown in Fig. 1, as well
as fluid bypass structures 18a of upper heat exchange plate 10a, as shown in Fig.
1.
Discussion of Possible Embodiments
[0027] A heat exchanger plate includes a heat transfer portion having a plurality of ribs
arranged in a rib pattern. It further includes a fluid ingress structure arranged
near a first corner of the heat exchanger plate. That structure includes a first open
fluid aperture defined in the heat exchanger plate and a first platform arranged between
the first open fluid aperture and the first corner, wherein the first platform is
connected to a rib of the rib pattern. The heat exchanger has a fluid bypass structure
near a second corner. That structure includes a closed fluid aperture defined in the
heat exchanger plate, a second platform completely surrounding the closed fluid aperture,
and a first corner rib arranged between the second platform and the second corner,
wherein the first corner rib is connected to a rib of the rib pattern.
[0028] The heat exchanger plate may also include a fluid egress aperture structure near
a third corner. That structure includes a second open fluid aperture defined in the
heat exchanger plate, and a third platform arranged between the second open fluid
aperture and the third corner, wherein the third platform is connected to at least
one rib of the rib pattern. The heat exchanger plate may also include a second fluid
bypass structure near a fourth corner. That structure includes a second closed fluid
aperture defined in the heat exchanger plate, a fourth platform completely surrounding
the second closed fluid aperture, and a second corner rib arranged between the fourth
platform and the fourth corner, wherein the second corner rib is connected to at least
one rib of the rib pattern. The heat exchanger plate may also have a second platform
that is configured to cooperate with an adjacent component to prevent fluid flow between
the closed fluid aperture and the heat transfer portion. The heat exchanger plate
may be a hot fluid plate and the adjacent component may be a cold fluid plate. The
first platform may be connected to a first rib of the rib pattern and the corner rib
may be connected to a second rib of the rib pattern. The rib pattern may be a herringbone
pattern. The distance between the fluid ingress aperture and the first platform may
be less than the distance between the second platform and the closed fluid aperture.
The first platform may be connected to at least two ribs of the rib pattern. The corner
rib may be connected to at least two ribs of the rib pattern. The first platform may
be connected to a first rib of the rib pattern, the third platform connected to a
second rib of the rib pattern, the first corner rib connected to a third rib of the
rib pattern, and the second corner rib connected to a fourth rib of the rib pattern.
The second platform may be connected to a rib of the rib pattern. The fourth platform
may be connected to a rib of the rib pattern.
[0029] A heat exchange system includes a first heat exchange plate. The first heat exchange
plate includes a first heat exchange portion including a plurality of ribs arranged
in a first rib pattern. It also includes a hot fluid ingress aperture defined by the
first heat exchange plate. The heat exchange plate includes a hot fluid egress aperture
defined by the first heat exchange plate, a first platform circumscribing a first
closed fluid aperture, and a second platform circumscribing a second closed fluid
aperture. The first heat exchange plate has a first corner rib arranged between the
first platform and a first corner of the first heat exchange plate that is closest
to the first platform, and a second corner rib arranged between the second platform
and a second corner of the first heat exchange plate that is closes to the second
platform. The heat exchange system also has a second heat exchange plate arranged
adjacent to the first heat exchange plate. The second heat exchange plate has a second
heat exchange portion including a plurality of ribs arranged in a second rib pattern.
The second heat exchange plate has a cold fluid ingress aperture arranged adjacent
to the first closed fluid apertures of the first heat exchange plate, and a cold fluid
egress aperture arranged adjacent to the second closed fluid apertures of the first
heat exchange plate.
[0030] The heat exchange system described above may also have a first platform that is connected
to a first rib of the first rib pattern and the second platform is connected to a
second rib of the first rib pattern. The first rib pattern and the second rib pattern
may both be herringbone patterns. The first corner rib may be connected to a third
rib of the first rib pattern and the second corner rib may be connected to a fourth
rib of the first rib pattern. The first heat exchange plate and the second heat exchange
plate may define a cavity therebetween. The heat exchange system may also include
a plurality of cavities defined by a plurality of additional heat exchange plates.
The first set of the plurality of cavities may be configured to route hot fluid and
a second set of the plurality of cavities may be configured to route cold fluid.
[0031] While the invention has been described with reference to an exemplary embodiment(s),
it will be understood by those skilled in the art that various changes may be made
and equivalents may be substituted for elements thereof without departing from the
scope of the invention. In addition, many modifications may be made to adapt a particular
situation or material to the teachings of the invention without departing from the
essential scope thereof. Therefore, it is intended that the invention not be limited
to the particular embodiment(s) disclosed, but that the invention will include all
embodiments falling within the scope of the appended claims.
1. A heat exchanger plate (10b), comprising:
a heat transfer portion having a plurality of ribs arranged in a rib pattern (12b);
a fluid ingress structure (14b) arranged near a first corner of the heat exchanger
plate (106), the fluid ingress structure (14b) comprising:
a first open fluid aperture (20) defined in the heat exchanger plate (10b); and
a first platform (22) arranged between the first open fluid aperture (20) and the
first corner, wherein the first platform (22) is connected to the rib pattern (12b);
and
a fluid bypass structure (18b) near a second corner, the fluid bypass structure (18b)
comprising:
a closed fluid aperture (26) defined in the heat exchanger plate (10b);
a second platform (28) completely surrounding the closed fluid aperture (26); and
a first corner rib (30) arranged between the second platform (28) and the second corner,
wherein the first corner rib (30) is connected the rib pattern (12b).
2. The heat exchanger plate (10b) of claim 1, wherein:
a first distance is defined between an edge of the first corner and the first platform
(22); and
a second distance is defined between the first platform (22) and the first open fluid
aperture (20); and
a ratio of the first distance to the second distance is between 0.5 and 2.0, and optionally
approximately 1.
3. The heat exchanger plate (10b) of claim 1 or 2, and further comprising a fluid egress
structure (14b) near a third corner, the fluid egress structure (14b) comprising:
a second open fluid aperture defined in the heat exchanger plate (10b); and
a third platform arranged between the second open fluid aperture and the third corner,
wherein the third platform is connected to the rib pattern (12b).
4. The heat exchanger plate (10b) of claim 3, further comprising a second fluid bypass
structure (18) near a fourth corner, the second fluid bypass structure (18) comprising:
a second closed fluid aperture defined in the heat exchanger plate (10);
a fourth platform completely surrounding the second closed fluid aperture; and
a second corner rib arranged between the fourth platform and the fourth corner, wherein
the second corner rib is connected to the rib pattern (12).
5. The heat exchanger plate (10b) of claim 4, wherein:
the first platform (22) is connected to a first rib of the rib pattern (12b);
the third platform is connected to a second rib of the rib pattern (12b);
the first corner rib (30) is connected to a third rib of the rib pattern (12b); and
the second corner rib is connected to a fourth rib of the rib pattern (12b).
6. The heat exchanger plate (10b) of any preceding claim, wherein the second platform
(28) is configured to cooperate with an adjacent component to prevent fluid flow between
the closed fluid aperture (26) and the heat transfer portion.
7. The heat exchanger plate (10b) of any preceding claim, wherein the first platform
(22) is connected to:
a first rib of the rib pattern (12b) and the first corner rib (30) is connected to
a second rib of the rib pattern; and/or
at least two ribs of the rib pattern (12).
8. The heat exchanger plate (10b) of any preceding claim, wherein a distance between
the fluid ingress open fluid aperture (20) and the first platform (22) is less than
a distance between the second platform (28) and the closed fluid aperture (26).
9. The heat exchanger plate (10b) of any preceding claim, wherein the second platform
(28) is connected to the rib pattern (12b).
10. A heat exchange system (8) comprising a plurality of heat exchange plates (10b) of
any preceding claims.
11. The heat exchange system (8) of claim 10, wherein the first platform (22) and the
second platform (28) of each of the plurality of heat exchange plates (10b) are connected
to the rib pattern (12b).
12. The heat exchange system (8) of claim 10 or 11, wherein adjacent panels of the plurality
of heat exchange plates (10b) define cavities therebetween.
13. The heat exchange system (8) of claim 12, wherein the fluid ingress structures (14b)
of the plurality of heat exchange plates (10b) are capable of selectively admitting
the hot fluid to the first subset of cavities and the fluid egress structures (18b)
of the plurality of heat exchange plates (10b) are capable of selectively taking up
the hot fluid from the first subset of cavities.
14. The heat exchange system (8) of claim 12 or 13, and further comprising:
a first subset of the cavities are configured to route a hot fluid; and
a second subset of the cavities are configured to route a relatively cooler fluid.
15. The heat exchange system (8) of claim 14, wherein the fluid ingress structures (14b)
of the plurality of heat exchanger plates (10b) are capable of selectively admitting
the cooler fluid to the second subset of cavities and the fluid egress structures
(18b) of the plurality of heat exchanger plates (10b) are capable of selectively taking
up the cooler fluid from the second subset of cavities.