U.S. patent application number 15/365215 was filed with the patent office on 2018-05-31 for configurable cooling assembly and cooling method.
The applicant listed for this patent is The Boeing Company. Invention is credited to Daniel A. Charles, Alex X. Zhu.
Application Number | 20180147800 15/365215 |
Document ID | / |
Family ID | 60191228 |
Filed Date | 2018-05-31 |
United States Patent
Application |
20180147800 |
Kind Code |
A1 |
Zhu; Alex X. ; et
al. |
May 31, 2018 |
Configurable Cooling Assembly and Cooling Method
Abstract
An assembly of thermally conductive cooling blocks is configured
to be placed against a composite skin between a heating blanket
used to thermally cure a composite repair patch and a structure
formed of a heat sensitive material. The cooling block assembly
conducts heat away from the skin to prevent overheating of the heat
sensitive material.
Inventors: |
Zhu; Alex X.; (Charleston,
SC) ; Charles; Daniel A.; (St. Louis, MO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Boeing Company |
Chicago |
IL |
US |
|
|
Family ID: |
60191228 |
Appl. No.: |
15/365215 |
Filed: |
November 30, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29L 2031/3076 20130101;
B29C 35/16 20130101; B29K 2101/10 20130101; B29C 73/12 20130101;
B29C 73/34 20130101; B29K 2105/253 20130101; B32B 27/00 20130101;
B32B 2605/18 20130101; B32B 2309/02 20130101; B29L 2009/00
20130101; B32B 37/06 20130101; B32B 2398/10 20130101; B29C 73/24
20130101; B29K 2105/246 20130101; B29C 65/242 20130101; B32B
2305/77 20130101; F28F 7/02 20130101 |
International
Class: |
B29C 73/12 20060101
B29C073/12; F28F 7/02 20060101 F28F007/02; B32B 27/00 20060101
B32B027/00; B32B 37/06 20060101 B32B037/06; B29C 65/24 20060101
B29C065/24 |
Claims
1. Apparatus for cooling a structure, comprising: an assembly of
configurable, thermally conductive cooling blocks configured to be
placed against a surface of the structure and fit within a
predetermined volume of space adjacent the structure.
2. The apparatus of claim 1, wherein the assembly includes a
plurality of the cooling blocks arranged in a three-dimensional
array.
3. The apparatus of claim 1, wherein each of the cooling blocks is
formed from one of: copper, and aluminum.
4. The apparatus of claim 1, wherein the cooling blocks include
releasable connections coupling the cooling blocks together, and
allowing the cooling blocks to be reconfigured.
5. The apparatus of claim 1, wherein at least certain of the
cooling blocks include at least one through-hole allowing passage
of air therethrough.
6. The apparatus of claim 1, wherein the assembly includes a
plurality of the cooling blocks arranged in a row and having
through-holes therein aligned to form an air passageway through the
cooling blocks in the row.
7. The apparatus of claim 6, including a fan configured to force
air through the air passageway.
8. Apparatus for preventing overheating of heat sensitive materials
near a repair patch being thermally cured on a composite skin by a
heat source, comprising: an assembly of thermally conductive
cooling blocks configured to be placed against the composite skin
for conducting heat away from the composite skin between the heat
sensitive material and the heat source.
9. The apparatus of claim 8, wherein the cooling blocks are formed
of one of: copper, and aluminum.
10. The apparatus of claim 8, wherein each of the cooling blocks is
cube shaped.
11. The apparatus of claim 8, wherein the cooling blocks are
arranged in a three-dimensional array.
12. The apparatus of claim 8, wherein the cooling blocks include
interconnections coupling the cooling blocks together.
13. The apparatus of claim 12, wherein the interconnections are
releasable to allow the shape of the assembly of the cooling blocks
to be reconfigured.
14. The apparatus of claim 12, wherein the interconnections include
one of: ways and gibs formed in each of the cooling blocks, pins
between the cooling blocks, snap fit fasteners, magnets, and a
conductive adhesive between the cooling blocks.
15. The apparatus of claim 8, wherein at least certain of the
cooling blocks include at least one through-hole therein allowing
air to pass therethrough.
16. A method of managing the temperature of heat sensitive
materials located near a repair patch being thermally cured on a
composite skin using a heating blanket, comprising: configuring an
assembly of thermally conductive cooling blocks to fit within a
space between the heating blanket and the heat sensitive material;
and installing the assembly of thermally conductive cooling blocks
against the skin within the space.
17. The method of claim 16, wherein the configuring includes:
placing the cooling blocks in an arrangement of rows and columns,
and holding the cooling blocks in the arrangement.
18. The method of claim 16, wherein the configuring includes
forming through-holes in at least certain of the cooling blocks
allowing air to pass therethrough.
19. The method of claim 18, including drawing heat away from the
cooling blocks by forcing air through the through-holes.
20. The method of claim 16, further comprising: disassembling the
assembly of the cooling blocks; and reassembling the cooling blocks
in another configuration.
Description
BACKGROUND INFORMATION
1. Field
[0001] The present disclosure generally relates to systems and
methods for cooling structures, and deals more particularly with an
array of configurable cooling blocks for conducting heat away from
a structure.
2. Background
[0002] It is sometimes necessary to protect heat sensitive
structures against overheating. For example, in order to carry out
an in-situ repair of a composite structure such as a composite
aircraft skin, a heating blanket is used to thermally cure a
composite repair patch placed on area of the skin requiring repair.
In some cases, the skin repair area is located close to heat
sensitive materials (HSM) such as an underlying peened titanium or
aluminum stiffener.
[0003] Depending on the difficulty of the application, shot bags
that act as heat sinks, chilled air and/or fans can be used to cool
the skin between the edge of the heating blanket and the HSM, in
order to prevent overheating of the HSM. In other applications,
however, the distance between the edge of the heating blanket and
the HSM may be relatively small, for example on the order of a few
inches, limiting the effectiveness of cooling fans. The challenge
of preventing overheating of HSMs is made more difficult by
complicated structural geometries and repair areas that are
hard-to-reach.
SUMMARY
[0004] The disclosure relates in general to cooling of structures
to prevent overheating of HSMs, and more specifically to a
configurable cooling assembly for use in conducting heat away from
HSMs in the proximity of a bonded repair.
[0005] According to one aspect, apparatus is provided for cooling a
structure, comprising an assembly of configurable, thermally
conductive cooling blocks. The cooling blocks are configured to be
placed against a surface of the structure and fit within a
predetermined volume of space adjacent to the structure.
[0006] According to another aspect, an apparatus is provided for
preventing overheating of heat sensitive materials near a repair
patch being thermally cured on a composite skin by a heat source.
The apparatus comprises an assembly of thermally conductive cooling
blocks configured to be placed against the composite skin for
conducting heat away from the composite skin between the heat
sensitive material and the heat source.
[0007] According to still another aspect, a method is provided of
managing the temperature of heat sensitive materials located near a
repair patch being thermally cured on a composite skin using a
heating blanket. The method comprises configuring an assembly of
thermally conductive cooling blocks to fit within a space between
the heat blanket and the heat sensitive material, and installing
the assembly of thermally conductive cooling blocks against the
skin within the space.
[0008] One of the advantages of the cooling assembly is that it is
simple, passive, may be installed in tight spaces and is readily
configurable to suit unusual or complex geometries of a structure
requiring cooling. Another advantage of the cooling assembly is
that it is reusable and can be reconfigured to achieve different
heat sink shapes and levels of cooling required in different
applications. A further advantage of the cooling assembly is that
it avoids the need for interrupting thermal curing of a composite
patch when there is a risk of overheating of the adjacent HSMs.
[0009] The features, functions, and advantages can be achieved
independently in various embodiments of the present disclosure or
may be combined in yet other embodiments in which further details
can be seen with reference to the following description and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The novel features believed characteristic of the
illustrative embodiments are set forth in the appended claims. The
illustrative embodiments, however, as well as a preferred mode of
use, further objectives and advantages thereof, will best be
understood by reference to the following detailed description of an
illustrative embodiment of the present disclosure when read in
conjunction with the accompanying drawings, wherein:
[0011] FIG. 1 is an illustration of a diagrammatic cross-sectional
view of a composite skin in which an HSM is located near an area of
skin requiring repair.
[0012] FIG. 2 is an illustration similar to FIG. 1 but showing
installation of a configurable cooling block assembly.
[0013] FIG. 3 is an illustration of a sectional view taken along
the line 3-3 in FIG. 2, wherein one of the cooling blocks is broken
away in section to reveal an internal through-hole.
[0014] FIG. 4 is an illustration of a perspective view of one of
the cooling blocks forming part of the configurable cooling block
assembly.
[0015] FIG. 5 is an illustration of a fragmentary side view of one
row of the cooling blocks shown in FIGS. 2 and 3, wherein the
blocks are broken away in section to reveal a continuous air
passageway through the row.
[0016] FIG. 6 is an illustration of an end view of several of the
cooling blocks, showing one form of interconnection between the
cooling blocks.
[0017] FIG. 7 is an illustration of an end view of several cooling
blocks, showing another form of interconnection between the cooling
blocks.
[0018] FIG. 8 is an illustration of an end view of several cooling
blocks, showing a further form of interconnection between the
cooling blocks.
[0019] FIG. 9 is an illustration of an end view of several the
cooling blocks held against an underlying composite skin by the
force of gravity.
[0020] FIG. 10 is an illustration of the area designated as "FIG.
10" in FIG. 9.
[0021] FIG. 11 is an illustration of a fragmentary, perspective
view showing use of the cooling blocks during repair of a composite
skin curved in two dimensions.
[0022] FIG. 12 is an illustration of an end view of two of the
cooling blocks supported on an underlying contoured skin
surface.
[0023] FIG. 13 is an illustration of the area designated as "FIG.
13" in FIG. 12.
[0024] FIG. 14 is an illustration of a flow diagram of a method for
cooling a structure that includes HSMs.
[0025] FIG. 15 is an illustration of a flow diagram of aircraft
production and service methodology.
[0026] FIG. 16 is an illustration of a block diagram of an
aircraft.
DETAILED DESCRIPTION
[0027] FIG. 1 illustrates a composite laminate structure such as a
composite aircraft skin 20 having an area 22 (hereinafter "repair
area") requiring in-situ repair or rework in order to correct an
out-of-specification condition such as impact damage. Although not
shown in the Figures, the repair is carried out using a cured or
uncured composite laminate patch that is bonded to the skin 20
using a bonding adhesive. A curing assembly (not shown) that
includes a heating blanket 28, is used to thermally cure the
bonding adhesive and/or the repair patch, which is typically
comprised of a fiber reinforced, thermoset or a thermoplastic
laminate. The curing assembly may also include a vacuum bag (not
shown) that is used to compact the repair patch during the cure
process.
[0028] The repair area 22 is located near a heat sensitive material
(HSM) 24 which, in the illustrated example, comprises a structural
stiffener 24a having a cap 26 which is bonded or otherwise fixed to
the surface 20a of the skin 20. A minimal amount of space 34 is
present between the edge 28a of the heating blanket 28 and the HSM
24. The stiffener 24a may comprise a HSM 24 such as, for example
and without limitation, a peened titanium or aluminum which may be
impacted if heated above a certain temperature. The temperature at
which the HSM 24 is impacted is less than the cure temperature (in
the case of a thermoset patch) or consolidation temperature (in the
case of a thermoplastic patch) of the repair patch. For convenience
in the remaining description "cure temperature" refers to the cure
temperature of a composite laminate repair patch formed of a
thermosetting polymer resin, a thermoplastic polymer resin, hybrid
material systems containing both thermosets and thermoplastics, and
bonding adhesives used to bond such patches to an underlying
structure such as the skin 20. Peened titanium stiffener 24a may be
impacted when exposed to temperatures exceeding 200.degree. F.
whereas the heating blanket 28 may generate temperatures well in
excess of 200.degree. F., for example 300-350.degree. F. for a
thermoset repair patch. During thermal curing of the repair patch,
thermal energy generated by the heating blanket 28 is transferred
both by conduction 30 through the skin 20 and radiation 32 to the
stiffener 24a, thereby raising the temperature of the HSM 24.
[0029] Referring now to FIG. 2-4, an assembly 36 of thermally
conductive cooling blocks 38 (hereinafter "cooling block assembly",
arranged in a three-dimensional array, is placed against the
surface 20a of the skin 20. As will be discussed below in more
detail, the cooling block assembly 36 is used to manage the
temperature of the HSM 24. The cooling block assembly 36 is
configured to fit within the space 34 (FIG. 1) between the edge of
the heating blanket 28 and the cap 26 of the stiffener 24a. In the
illustrated example, the cooling block assembly 36 comprises a
three-dimensional array of individual cooling blocks 38, arranged
in five layers on an underlying support 39 that holds the cooling
block assembly 36 against the skin surface 20a. In the Figures, the
support 39 comprises a flat plate driven upwardly by a jack or
similar force applicator, forcing the assembly 36 of cooling blocks
38 against the skin surface 20a. However, a variety of other means
of supporting the cooling blocks 38 and forcing them against the
skin surface 20a are possible, such as straps, scaffolding, etc.
While five layers 44 of cooling blocks 38 are illustrated in FIGS.
2 and 3, more than five layers 44 or as few as one layer 44 may be
suitable, depending upon the application. Also, while the layers 44
of cooling blocks 38 are shown as staggered relative to each other
in FIGS. 2 and 3 to increase the exposed surface area of the
assembly, they may be vertically aligned so as to form rows and
columns.
[0030] The cooling block assembly 36 manages the temperature of the
HSM 24 by acting as a heat sink, conducting a portion 46 of the
heat out of the skin away from the HSM 24, such that only a
residual portion 48 of the heat conducted through the skin 20
reaches the HSM 24. The amount of heat that is conducted away from
the skin 20 by the cooling block assembly 36 will depend on a
number of factors, including but not limited to the number of
cooling blocks 38 in contact with the surface 20a of the skin 20,
the thermal conductivity of the cooling blocks 38, the collective
mass of the cooling blocks 38 and the surface area of the cooling
blocks 38 that is exposed to the surrounding environment. In
addition to reducing the heat conducted through the skin to the HSM
24, the cooling block assembly 36 also absorbs heat that is
radiated 32 by the heating blanket 28, which would otherwise impact
the HSM 24.
[0031] As best seen in FIG. 4, each of the cooling blocks 38 is in
the shape of a cube, having a height H, width W, and length L
dimensions that are equal. In other examples, however, these
dimensions may be unequal. For example, each of the cooling blocks
38 maybe elongate, wherein its length L is considerably greater
than either its height H or width W. Further, while the illustrated
cooling block 38 is a shape that has flat sides which maximize the
surface contact between the cooling blocks 38, other shapes are
possible. For example, the cooling blocks 38 may be rectangular,
cylindrical or pyramidal in shape, to name only a few
possibilities. The surfaces of the cooling blocks 38 should have
smooth surfaces with minimal porosity in order to maximize heat
transfer between the interfacial boundaries of adjacent blocks 38.
The cooling blocks 38 are formed of a material that is relatively
high in thermal conductivity and is easily machined, such as,
without limitation, copper or aluminum, or an alloy of these two or
other thermally conductive materials. The thermal conductivity of
the cooling blocks 38 should be sufficient to result in minimal
residual heat conduction 48 to the HSM 24.
[0032] Depending on the application, certain cooling blocks 38 may
have one or more through-holes 40 therein, each of which has a
suitable diameter. In the illustrated example, the top or first
layer 44 of cooling blocks 38 in contact with the skin 20 do not
have any through-holes 40, while the cooling blocks 38 in the
second and third layers 44 each have a single through-hole 40, and
the cooling blocks 38 in the fourth and fifth layers 44 each have
four through-holes 40. The through-holes 40 increase the exposed
surface area of the cooling blocks 38 and therefore increase the
amount of heat that is radiated away from the cooling blocks 38 to
the surrounding environment. In applications where the space 34
(FIG. 1) between the edge 28a of the heating blanket 28 and the HSM
24 is relatively small, it may be desirable to use cooling blocks
38 closest to the skin 20 that do not have through-holes 40 because
the absence of through-holes 40 increases the thermal mass of those
cooling blocks 38, allowing them to conduct heat away from the skin
20 more quickly.
[0033] Referring now also to FIG. 5, in one example, the cooling
blocks 38 are arranged such that the through-holes 40 are aligned
to form continuous air passageways through the cooling block
assembly 36, allowing passive convection cooling. Optionally,
active cooling may be achieved by employing a fan 52 or other
forced air source to force air 50 through the passageways 42. The
air 50 flowing through the passageways 42 draws heat away from the
cooling block assembly 36, thereby enhancing its ability to cool
the skin 20 and reduce elevation of the temperature of the HSM 24
caused by the heating blanket 28.
[0034] Depending on the application, it may be necessary or
desirable to releasably connect the cooling blocks 38 together,
either by releasable mechanical interconnections, adherents or
other means. FIG. 6 illustrates one arrangement for mechanically
interconnecting the cooling blocks 38 using interlocking gibs 54
and ways 56 which allow the cooling blocks 38 to be slidably
assembled with each other. FIG. 7 illustrates another arrangement
in which each of the cooling blocks 38 includes one or more
recessed magnets 58. The magnets 58 in adjacent cooling blocks 38
are aligned with and attract each other, holding the cooling blocks
38 together in the assembly 36 by magnetic forces. FIG. 8
illustrates a further arrangement in which pins or releasable snap
fit fasteners 60, such as, without limitation, ball and socket
connections are used to interconnect the cooling blocks 38. In some
applications the fasteners 60 may comprise simple pins. A variety
of other techniques can be used to hold the cooling blocks 38
together as an assembly 36, including but not limited to thermally
conductive adhesives.
[0035] FIGS. 9 and 10 illustrate another example in which an
assembly 36 of cooling blocks 38 (only three of which are shown in
the Figures) are held against a composite skin 20 using the force
of gravity G. In order to locate and position layers of the cooling
blocks 38 relative to each other, the bottom 38a of each of the
cooling blocks 38 is provided with one or more raised locating
balls 64 that are received within corresponding indexing recesses
62 in the top surfaces 38b of an underlying cooling block 38.
[0036] The cooling block assembly 36 may be used to conduct heat
away from a curved or contoured composite skin 20. For example,
referring to FIGS. 11-13, one or more layers 44 of cooling blocks
38 are arranged on top of a composite skin 20, positioned within a
space 34 between the edge 28a of a heating blanket 28, and an
underlying stiffener 24a formed of a HSM 24. The composite skin 20
is curved in two dimensions, and the cooling block assembly 36
substantially conforms to the contour of the skin 20. Referring
particularly to FIGS. 12 and 13, the bottom 38a of each cooling
block 38 is substantially flat, and thus forms a slight gap 68
(FIG. 13) between the cooling block 38 and the skin surface
20a.
[0037] Depending on the application, a thermally conductive liquid
shim 70 may be used to fill the gap 68 in order to prevent or
minimize reduction of the heat transferred from the skin 20 to the
cooling blocks 38. Depending on the degree of curvature of the skin
surface 20a, a relatively small, pie-shaped gap 66 may be formed
between the walls of adjacent ones of the cooling blocks 38. The
gaps 66 may be used to allow convective air currents to pass
through the cooling block assembly 36, optionally aided by a fan
(FIG. 5) that forces air through the gap 66. Alternatively, the
gaps 66 may be filled with the liquid shim 70. In some
applications, thermally conductive metal shims (not shown) may be
employed to fill either of the gaps 66, 68.
[0038] Embodiments of the disclosure may find use in a variety of
potential applications, particularly in the transportation
industry, including for example, aerospace, marine, automotive
applications and other application where heat sensitive materials
must be protected from overheating. Thus, referring now to FIGS. 15
and 16, embodiments of the disclosure may be used in the context of
an aircraft manufacturing and service method 84 as shown in FIG. 15
and an aircraft 86 as shown in FIG. 16. Aircraft applications of
the disclosed embodiments may include, for example, without
limitation, fuel and hydraulic systems that use tubes containing
pressurized fluids. During pre-production, exemplary method 84 may
include specification and design of the aircraft 86 and material
procurement 90. During production, component and subassembly
manufacturing 92 and system integration 94 of the aircraft 86 takes
place. Thereafter, the aircraft 86 may go through certification and
delivery 96 in order to be placed in service 98. While in service
by a customer, the aircraft 86 is scheduled for routine maintenance
and service 100, which may also include modification,
reconfiguration, refurbishment, and so on.
[0039] Each of the processes of method 84 may be performed or
carried out by a system integrator, a third party, and/or an
operator (e.g., a customer). For the purposes of this description,
a system integrator may include without limitation any number of
aircraft manufacturers and major-system subcontractors; a third
party may include without limitation any number of vendors,
subcontractors, and suppliers; and an operator may be an airline,
leasing company, military entity, service organization, and so
on.
[0040] As shown in FIG. 16 the aircraft 86 produced by exemplary
method 84 may include an airframe 102 with a plurality of systems
104 and an interior 106. The airframe 102 may include heat
sensitive materials that must be protected from overheating during
for example, thermal curing of composite repairs. Examples of
high-level systems 104 include one or more of a propulsion system
108, an electrical system 110, a hydraulic system 112 and an
environmental system 114. Any number of other systems may be
included. Although an aerospace example is shown, the principles of
the disclosure may be applied to other industries, such as the
marine and automotive industries.
[0041] Systems and methods embodied herein may be employed during
any one or more of the stages of the production and service method
84. For example, components or subassemblies corresponding to
production process 92 may be fabricated or manufactured in a manner
similar to components or subassemblies produced while the aircraft
86 is in service. Also, one or more apparatus embodiments, method
embodiments, or a combination thereof may be utilized during the
production stages 92 and 94, for example, by substantially
expediting assembly of or reducing the cost of an aircraft 86.
Similarly, one or more of apparatus embodiments, method
embodiments, or a combination thereof may be utilized while the
aircraft 86 is in service, for example and without limitation, to
maintenance and service 100.
[0042] As used herein, the phrase "at least one of", when used with
a list of items, means different combinations of one or more of the
listed items may be used and only one of each item in the list may
be needed. For example, "at least one of item A, item B, and item
C" may include, without limitation, item A, item A and item B, or
item B. This example also may include item A, item B, and item C or
item B and item C. The item may be a particular object, thing, or a
category. In other words, at least one of means any combination
items and number of items may be used from the list but not all of
the items in the list are required.
[0043] The description of the different illustrative embodiments
has been presented for purposes of illustration and description,
and is not intended to be exhaustive or limited to the embodiments
in the form disclosed. Many modifications and variations will be
apparent to those of ordinary skill in the art. Further, different
illustrative embodiments may provide different advantages as
compared to other illustrative embodiments. The embodiment or
embodiments selected are chosen and described in order to best
explain the principles of the embodiments, the practical
application, and to enable others of ordinary skill in the art to
understand the disclosure for various embodiments with various
modifications as are suited to the particular use contemplated.
* * * * *