U.S. patent application number 14/349164 was filed with the patent office on 2014-09-04 for solar heat exchange panel.
The applicant listed for this patent is LRM Industries International, Inc.. Invention is credited to Dale E. Polk, JR..
Application Number | 20140246011 14/349164 |
Document ID | / |
Family ID | 48044372 |
Filed Date | 2014-09-04 |
United States Patent
Application |
20140246011 |
Kind Code |
A1 |
Polk, JR.; Dale E. |
September 4, 2014 |
Solar Heat Exchange Panel
Abstract
A solar heat exchange panel that includes a lower plate and an
upper plate that together define an interior volume containing a
flowing heat transfer fluid. The upper plate includes a plurality
of upward extensions and downward extensions that cover the top
surface of the solar heat transfer panel and are configured to
capture solar radiant energy. The lower plate plate includes a
plurality of upwardly extending hollow lower plate extensions. The
lower plate extensions are aligned with the bottom portions of each
upward extension of the upper plate and almost touching. Each of
the downward extensions form the upper plate extend down and are
joined to the base of the lower plate. In operation, a heat
transfer fluid introduced into an inlet on one end of the solar
heat transfer panel passes through the defined interior volume and
is intimately contacted with the solar heated surfaces extending
down into the solar heat transfer panel from the upper plate. A
substantially infrared transparent plate across the top surface of
the solar heat transfer panel creates a top interior space that
encloses a path of flowing air which is simultaneously heated along
with the enclosed heat transfer fluid in the lower interior
space.
Inventors: |
Polk, JR.; Dale E.;
(Titusville, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LRM Industries International, Inc. |
Rockledge |
FL |
US |
|
|
Family ID: |
48044372 |
Appl. No.: |
14/349164 |
Filed: |
October 2, 2012 |
PCT Filed: |
October 2, 2012 |
PCT NO: |
PCT/US2012/058461 |
371 Date: |
April 2, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61542382 |
Oct 3, 2011 |
|
|
|
Current U.S.
Class: |
126/674 |
Current CPC
Class: |
Y02E 10/44 20130101;
F24S 10/50 20180501; F24S 10/55 20180501; F24S 10/20 20180501; F24S
10/502 20180501; F24S 10/504 20180501 |
Class at
Publication: |
126/674 |
International
Class: |
F24J 2/04 20060101
F24J002/04; F24J 2/22 20060101 F24J002/22; F24J 2/20 20060101
F24J002/20 |
Claims
1. A solar heat exchange panel (10) comprising: a. a lower plate
(320) and an upper plate (310) that together define a lower
interior volume containing a flowing heat transfer fluid; b. said
upper plate (310) comprising: i. a plurality of upward dimples (50)
and downward pockets (60) that cover a top surface of the solar
heat transfer panel and are configured to capture solar radiant
energy; c. said lower plate (320) plate comprising: i. a plurality
of upwardly extending hollow lower plate extensions (330); d.
wherein the lower plate extensions (330) are aligned with the
center bottom portions of each dimple (50) of the upper plate and
almost touching; and e. wherein the downward pockets (60) from the
upper plate (310) extend down and are joined to the base of the
lower plate (320); and f. wherein a substantially infrared
transparent plate across the top surface of the solar heat transfer
panel encloses a top interior space that provides a path of flowing
air which is simultaneously heated along with the enclosed heat
transfer fluid in the lower interior space.
2. The solar heat exchange panel of claim 1 further comprising a
sidewall structure (25) that surrounds said heat exchange panel and
the top of said sidewall structure has a shelf structure (40) to
accept the substantially infrared transparent plate that encloses
the top interior space.
3. The solar heat exchange panel of claim 2 wherein said sidewall
structure has at least one valley (20) to allow the insertion of
interconnecting air flow pipes (130) that connect adjacent solar
heat exchange panels into a network.
4. The solar heat exchange panel of claim 2 wherein said sidewall
structure has inlet (30) and exit (35) pipes that are used to
connect the heat transfer fluids from lower interior volumes to
adjacent solar heat exchange panels into a network.
5. The solar heat exchange panel of claim 1 wherein the deepest
center portion of each dimple (50) on the upper plate is molded to
the top of each extension (330) from lower plate (320).
6. The solar heat exchange panel of claim 2 wherein at least one
indentation (450) is present in the sidewall structure to break the
flow patterns of heat transfer fluid in the lower interior
volume.
7. The solar heat exchange panel of claim 2 wherein an additional
insulated box or panel is placed around the bottom base of the
solar heat transfer panel.
8. A solar heat exchange panel system in which a series of solar
heat exchange panels as described in claim 4 are interconnected so
that both the air in the top interior space and the heat transfer
fluid in the lower interior space can flow from panel to panel.
Description
PRIORITY
[0001] This application claims the priority of U.S. provisional
application 61/542,382 by the same inventor filed Oct. 3, 2011.
FIELD OF THE INVENTION
[0002] The invention described herein generally relates to a solar
heat transfer panel and more particularly to a lightweight and
easily manufactured polymer or polymer composite panel which can be
flexibly combined in various configurations to heat both liquid
fluids and air simultaneously.
BACKGROUND OF THE INVENTION
[0003] Solar heat exchange panels typically include a plurality of
channels through which a fluid, such as a heat exchange fluid
(e.g., water) is passed. Typically, a heat exchange panel is
oriented so as to expose the exterior surfaces of the channels to a
source of thermal energy, such as radiant heat (e.g., the sun). The
channels are heated by exposure to the heat source, and thermal
energy is transferred to the fluid passing through the interior of
the channels. The heated fluid may be used directly or indirectly,
e.g., to heat another fluid, such as air or water, in which case
the heated fluid is typically described as a heat exchange
fluid.
[0004] The cost and difficulty of manufacture has been a limiting
factor to acceptance of many of these systems. Especially those
made of metals. A number of plastic based systems have been
proposed in an attempt to lower both the cost and the weight of the
systems, particularly because of a desire to place many of these
systems on rooftops. The use of plastic materials have then
introduced issues of strength and rigidity.
[0005] In addition many of these systems have been limited to
either liquid (e.g. water) or gas (e.g. air) systems.
[0006] Attempts have been made to improve the efficiency of solar
heat exchange panels by increasing the surface area of the exterior
channel surfaces that are exposed to radiant energy. For example,
solar heat exchange panels having V-shaped or triangular shaped
exterior channel surfaces have been disclosed. See for example,
U.S. Pat. Nos. 4,290,413; 4,243,020; and 4,171,694.
[0007] U.S. application Ser. No. 13/144,254 describes a heat
exchange panel comprising an upper and lower plate with a series of
extensions between them defining a hollow interior space used to
pass a fluid through. It provides a panel that can be used for
solar heating but is relatively difficult to manufacture and does
not provide a top surface that effectively captures enough solar
energy.
[0008] It would be desirable to develop a new solar heat exchange
panels having improved efficiencies. In particular, it would be
desirable that such newly developed heat exchange panels provide a
favorable balance and coupling of factors including light weight,
optimum thermal transfer, optimum heat exchange fluid through-put,
minimum panel dimensions, the ability to heat both fluids and
gases, and the ability to easily connect multiple arrays of the
panels for various applications. In addition, it would be further
desirable that such newly developed heat exchange panels lend
themselves to relative ease of manufacture, assembly and use.
SUMMARY OF THE INVENTION
[0009] These needs are met by providing a solar heat exchange panel
(10) that includes a lower plate (320) and an upper plate (310)
that together define an interior volume containing a flowing heat
transfer fluid. The upper plate (310) includes a plurality of
upward extensions (50), herein referred to as dimples, and downward
extensions (60), herein referred to as pockets, that cover the top
surface of the solar heat transfer panel and are configured to
capture solar radiant energy. The lower plate (320) plate includes
a plurality of upwardly extending hollow lower plate extensions
(330). The lower plate extensions (330) are aligned with the center
bottom portions of each upward extension (50) of the upper plate
and almost touching. Each of the downward extensions (60) from the
upper plate (310) extend down and are joined to the base of the
lower plate (320). In operation, a heat transfer fluid introduced
into an inlet (30) on one end of the solar heat transfer panel
passes through the defined interior volume and is intimately
contacted with the solar heated surfaces extending down into the
solar heat transfer panel from the upper plate. A substantially
infrared transparent plate across the top surface of the solar heat
transfer panel creates a top interior space that encloses a path of
flowing air which is simultaneously heated along with the enclosed
heat transfer fluid in the lower interior space.
[0010] In another aspect the solar heat transfer panel is molded in
such a way that in such a way that the upwardly extending hollow
lower plate extensions (330) are molded to join or knit to the
center bottom portions of each upward extension (50) of the upper
plate.
[0011] The features that characterize the solar heat transfer panel
are described in this disclosure. The operating advantages and the
capabilities obtained by its use will be more fully understood from
the following detailed description and accompanying drawings in
which preferred (though non-limiting) embodiments are illustrated
and described.
[0012] As used herein and in the claims, terms of orientation and
position, such as, "upper", "lower", "top", "bottom", "exterior",
"interior" and similar terms, are used to describe the invention as
oriented and depicted in the drawings. Unless otherwise indicated,
the use of such terms is not intended to represent a limitation
upon the scope of the invention, in that the invention may adopt
alternative positions and orientations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a representative perspective top view of a solar
heat exchange panel.
[0014] FIG. 2 is a representative perspective view of a series of
the solar heat exchange panel of FIG. 1 configured for both liquid
and gas communication between panels.
[0015] FIG. 3 is a representative perspective view of a cross
section of the heat exchange panel of FIG. 1.
[0016] FIG. 4 is another perspective view of a cross section of the
heat exchange panel of FIG. 1.
[0017] FIG. 5 is another perspective view of a cross section of the
heat exchange panel of FIG. 1.
[0018] FIG. 6 is another perspective view of a cross section of the
heat exchange panel of FIG. 1.
[0019] FIG. 7 is a perspective view of a cross section of an
embodiment the heat exchange panel of FIG. 1.
[0020] FIG. 8 is a representative perspective bottom view of a
solar heat exchange panel.
[0021] FIG. 9 illustrates a stimulation of the flow patterns
achieved in the design illustrated in FIGS. 1-8.
[0022] In FIGS. 1 through 9, like reference numerals designate the
same components and structural features, unless otherwise
indicated.
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIGS. 1 and 2 are perspective views that exhibit a single
solar heat exchange panel 10 and a system of connected solar heat
exchange panels 100 connected into a network. Beginning with FIG. 1
a perspective view of a solar heat exchange panel is shown as the
numeral 10. The view is looking down on the top surface of the
solar panel, which would receive the solar radiation. On each end
of the solar heat exchange panel is an inlet 30 and an exit 35 for
the transfer of a heat exchange fluid into and out of the interior
volume of the panel. The interior arrangement and volume of the
solar heat exchange panel will be shown in subsequent drawings. The
heat exchange fluid would commonly be water but could be other
suitable fluids. The interior top surface of the solar heat
transfer panel consists of a repeated series of deep pockets 60 and
raised dimples 50 that make up an upper plate of the solar heat
transfer panel. That upper plate and a lower plate to be described
in subsequent drawings enclose the interior volume of the panel.
Solar heat exchange panel 10 is surrounded by a sidewall structure
25 and the top of that structure has a shelf structure 40
substantially encircling the top of the solar panel. Shelf 40 can
accept a flat infrared transparent plate (not shown) that would
cover the top portion of the solar heat transfer panel, creating an
enclosed volume between the interior top surface of the solar heat
transfer panel and the infrared transparent plate. This enclosed
volume can be used for heating air which can then flow from panel
to panel through interconnecting pipes 130.
[0024] At selected locations around the sidewall structure 25 there
are small valleys 20 that allow the insertion of the
interconnecting pipes 130. As shown in FIG. 2 the air flow pipes
130 are used to connect panels 110 and 120 as well as panels 120
and 125. For configurations in which no interconnecting air pipe is
needed a suitable plug 150 is inserted in valleys 20. In a similar
manner inlet 30 and exit 35 are used to flow the heat transfer
liquid fluids from panel 110 to panel 120. As can be seen an
important aspect of the solar heat transfer panels is the ability
to simultaneously heat both air and a liquid fluid simultaneously
in the same system. These air and liquid flows can flow
concurrently or counter currently from panel to panel.
[0025] In FIG. 3, shown as the numeral 300 is a perspective view of
the panel of FIG. 1, this time shown in a cross section to show the
interior structure of the solar heat transfer panel. The cross
section is cut through the center of a row of the dimple structures
50. The solar heat transfer panel is shown to have an upper plate
310 and a lower plate 320. The lower surface surface of upper plate
310 and the upper surface of lower plate 320 bound an interior
volume of the solar heat transfer panel through which the liquid
heat transfer fluid flows as it enters one end of the panel at
inlet 30 and exits at the other end at outlet 35. Lower plate 320
has a continuing series of extensions appearing as "hills" 330
extending up from the lowest plane of lower plate 320, each one
extending up to and very near the bottom of the dimples 50
immediately above them.
[0026] This is further exhibited in FIG. 4, in a side view
represented by the numeral 400 showing how each of the lower plate
extensions 330 extend up almost to the bottom trough of each of the
upper plate dimples 50. This design choice ensures turbulent flow
and mixing of the heat transfer fluid as it passes through the
solar heat transfer panel.
[0027] FIG. 5, shown generally as the numeral 500 is the same cross
sectional view as FIGS. 3 and 4 but from a different angle and
shows the interior volume bounded by the upper surface of lower
plate 320 and the lower surface of plate 310. Also shown here is
how the lower portion 355 of the deep pockets 60 extend all the way
down to the upper surface of lower plate 320 and are molded to that
upper surface of plate 320 to increase the strength and stiffness
of the solar heat transfer panel. In addition those deep pockets
represent a way of capturing many of the incident solar rays deep
into the space of the solar heat transfer panel as rays that enter
are reflected deeper into the pockets rather than reflecting back
into space. These deep pockets then extend well down into the
interior volume occupied by the flowing heat transfer fluid.
Similarly the dimple structures 50 have a curvature that captures
much more of the radiant energy, and effectively transfers it into
the interior fluids. Thus the alternating deep pocket/dimple
configuration provides improved energy capture from the radiant
solar energy, effectively transfers it deep into the panel, and
provides increased turbulent flow of the heat transfer fluids which
provides improved heat transfer from the upper plate into the
contained fluids.
[0028] In FIG. 6 the same solar heat transfer panel as shown in
FIGS. 3,4, and 5 is shown but with the cross section being taken
through a row of the deep pockets to show the interior volume in a
different way. The deep pockets 60 are now seen more directly and
in particular their contact 420 with the bottom plate 320 at 420.
The deep pockets are thus molded to the bottom plate 320 at
multiple position across the solar heat transfer panel during the
molding process to improve the strength and stiffness of the
resultant solar heat transfer panel.
[0029] FIG. 7 is the same view as FIG. 5 but showing another
embodiment in which the panel is molded in such as way that the
deepest center portion of each dimple 50 on the upper plate is
molded to the top of each extension 330 from lower plate 320. This
embodiment provides stiffness and strength to the solar heat
transfer panel. The joined portions 55 are shown. The stiffer
design allows thinner upper and lower plates and therefore improved
heat transfer internally to the heat transfer fluids.
[0030] FIG. 8, shown generally as numeral 800 is a perspective view
of the bottom side of the solar heat transfer panel--that is the
side on the opposite side that receives the solar rays. The deep
areas 430 are the undersides of the extensions or `hills" 330 shown
in for example FIGS. 4 and FIG. 7. Indentations 450 in the
sidewalls 25 are molded into the design to break the flow patterns
in the lower interior volume and insure that the flow of the heat
transfer fluid through the panel does not short circuit around the
outside but instead maintains a well mixed flow through the portion
of the panel interior that maximizes heat transfer to the fluid
from the deep pocket surfaces 355 of FIG. 5.
[0031] The plastic materials of these solar heat transfer panels
are molded thin to minimize weight and improve conductive heat
transfer. For very high operating temperatures the bottom side of
the solar heat transfer panel, as shown in FIG. 8, may lose too
much heat to the environment. For that possibility an additional
insulated box or panel (not shown) could be placed around the
bottom base of the solar heat transfer panel. This insulated "box"
could be manufactured of any suitable insulating material. An
example could be a box of suitably thick Styrofoam, but other
insulating materials are possible.
[0032] In use it is desirable to achieve a good turbulent flow of
the heat transfer fluid through the interior of the solar heat
transfer panel to maximize efficiency. In the design process a
finite element flow simulation was used to evaluate different
configurations. The flow analysis for the solar heat transfer panel
shown in FIGS. 1-8 is shown in FIG. 9. The flow pattern is very
efficient and shows the importance of the indentations 450, without
which the flow exhibits a highly by-passed behavior with most of
the fluid flowing around the outside walls of the panel. The
indentations 450 create a structures within the lower interior
volume that force the heat transfer fluid to follow a tortuous path
through the lower interior volume in each panel.
[0033] In operation of the solar heat exchange panel, a heat
exchange fluid enters into inlet 30, and follows a tortuous path
through the lower interior space and experiences turbulent flow
around the downward solar heated extensions 355 (FIG. 5) from the
upper plate and the upward extensions 330 (FIG. 3) of the lower
plate, transferring the collected radiant heat from the solar side
of the solar heat transfer panel into the fluid, which eventually
exits at 35.
[0034] In other embodiments of the solar heat transfer panel shown,
the shape of the upper portion of the lower plate extensions 330 is
not limited to the ones shown, but could be selected from more
rectangular shapes or from truncated pyramidal shapes having an
upper truncated surface. The upper truncated surface would define
the upper transverse surface of the upper portion of the lower
plate extension. Similarly the shape of the lower portion of the
upper plate extensions 355 is not limited to the ones shown, but
could be selected from more rectangular shapes or from truncated
pyramidal shapes having an upper truncated surface. The upper
truncated surface would define the upper transverse surface of the
upper portion of the lower plate extension. The inventive concept
in the solar heat transfer panel is not limited to the shapes shown
in FIGS. 1-8.
[0035] As described earlier the solar heat exchange panel may
optionally further include a plate (not shown) that covers the open
top defined by the sidewall structure. The plate is typically
substantially transparent to infrared radiation, and may rest on
and optionally be fixedly attached to the upper terminus of the
sidewall structure. The term "substantially infrared transparent"
and similar terms means the plate allows a major amount (e.g., at
least 50 percent) of the incident infrared radiation to pass
therethrough and into the interior sidewall structure space. The
substantially infrared transparent plate may optionally be fixedly
attached across the top of sidewalls 25 by for example: adhesives
(not shown); fasteners (not shown) extending through the plate and
into the sidewall structure; and/or snap fittings (not shown). The
plate substantially encloses the interior sidewall structure
space.
[0036] In a further embodiment of the present invention, the
sidewall structure includes a shelf 40 upon which the infrared
transparent plate is placed. With the shelf embodiment, the height
of the sidewall structure is greater than the maximum height of the
plurality of upper plate dimples 50.
[0037] The substantially infrared transparent plate of the solar
heat exchange panel, allows infrared radiation to enter the
interior sidewall structure space, and be absorbed at least in part
by the exterior surfaces of upper plate dimples 50, the deep
pockets 60, and other exterior surfaces of upper plate 310, such
that a substantial part of the heat energy is transferred to a heat
exchange fluid flowing through the interior passages. In addition,
the infrared transparent plate prevents foreign materials (e.g.,
precipitation, leaves and bird droppings) from entering interior
sidewall structure space and fouling the exterior surfaces of the
upper plate extensions. The infrared transparent plate itself can
be easily cleaned. The infrared transparent plate also allows a
gas, such as air, to be retained within interior sidewall structure
space and heated by the incident infrared radiation, thus resulting
in convective transfer of heat energy from the heated entrapped gas
to/through the upper plate 310 and into the heat exchange fluid
flowing through the interior passages of the solar heat transfer
panel.
[0038] In addition the capacity to heat the air within the interior
sidewall structure can be used to pass air through the solar heat
transfer panel simultaneously with an interior heat transfer fluid,
making the solar heat transfer panel into a dual purpose heater
that can, for example, simultaneously heat water and air.
[0039] The infrared transparent plate covering the open top and
enclosing the interior sidewall structure space of the sidewall
structure may be fabricated from any suitable infrared transparent
material, such as glass and/or plastics, such as thermoset plastic
materials and/or thermoplastic materials (e.g., thermoplastic
polycarbonate). Typically, the infrared transparent plate is rigid
and substantially self-supporting.
[0040] The heat exchange panel of the present invention, and the
various components may each be independently fabricated from any
suitable material or combinations of materials. Materials from
which the heat exchange panel of the present invention, and the
various components thereof, may be fabricated, include but are not
limited to, metals (e.g., ferrous metals, titanium, copper and/or
aluminum), cellulose based materials, such as wood, ceramics,
glass, and/or plastics (e.g., thermoplastic materials and/or
thermoset plastic materials).
[0041] In a preferred embodiment that leads to lighter weight and
ease of manufacture the solar heat exchange panel can be
manufactured from polymer or polymer composite materials in a
molding operation, using either thermoplastic or thermoset
polymers. The molded plastic components of the heat exchange panel
of the present invention may be prepared by a number of molding
methods, including, but not limited to, blow molding, injection
molding, reaction injection molding, compression molding and sheet
thermoforming.
[0042] In a further embodiment of the solar heat transfer panel the
top surface (solar facing) of the panel can be coated by "selective
surfaces" or selective absorbers. These surfaces take advantage of
the differing wavelengths of incident solar radiation and the
emissive radiation from the absorbing surface. Different
combinations of materials are often used. Example selective
surfaces include copper with a layer of back cupric oxide, steel
plated with gold, silicon, and silicon dioxide, and black chromium
nickel plated copper.
[0043] As used in this description, the term "thermoset polymers"
and similar terms, such as "thermosetting or thermosetable
polymers" means plastic materials having or that form a three
dimensional crosslinked network resulting from the formation of
covalent bonds between chemically reactive groups, e.g., active
hydrogen groups and free isocyanate groups, or between unsaturated
groups. Thermoset plastic materials from which the various
components of the solar heat exchange panel may be fabricated
include for example crosslinked polyurethanes, crosslinked
polyepoxides, crosslinked polyesters (such as sheet molding
compound compositions) and crosslinked polyunsaturated polymers.
The use of thermosetting plastic materials typically involves
reaction injection molding. Reaction injection molding typically
involves injecting separately, and preferably simultaneously, into
a mold, for example: (i) an active hydrogen functional component
(e.g., a polyol and/or polyamine); and (ii) an isocyanate
functional component (e.g., a diisocyanate such as toluene
diisocyanate, and/or dimers and trimers of a diisocyanate such as
toluene diisocyanate). The filled mold may optionally be heated to
ensure and/or hasten complete reaction of the injected
components.
[0044] As used in this description, the term "thermoplastic
polymer" and similar terms, means a polymer material that has a
softening or melting point, and is substantially free of a three
dimensional crosslinked network resulting from the formation of
covalent bonds between chemically reactive groups (e.g., active
hydrogen groups and free isocyanate groups) of separate polymer
chains and/or crosslinking agents. Examples of thermoplastic
materials from which the various components of the solar heat
exchange panel may be fabricated include, but are not limited to,
thermoplastic polyurethane, thermoplastic polyurea, thermoplastic
polyimide, thermoplastic polyamide, thermoplastic polyamideimide,
thermoplastic polyester, thermoplastic polycarbonate, thermoplastic
polysulfone, thermoplastic polyketone, thermoplastic polyolefins,
thermoplastic (meth)acrylates, thermoplastic
acrylonitrile-butadiene-styrene, thermoplastic
styrene-acrylonitrile, thermoplastic
acrylonitrile-stryrene-acrylate and combinations.
[0045] In an embodiment of the present invention, the thermoplastic
material from which each of the various components of the heat
exchange panel may be fabricated is independently selected from
thermoplastic polyolefins. As used herein and in the claims, the
term "polyolefin" and similar terms, such as "polyalkylene" and
"thermoplastic polyolefin", means polyolefin homopolymers,
polyolefin copolymers, homogeneous polyolefins and/or heterogeneous
polyolefins. For purposes of illustration, examples of a polyolefin
copolymer include those prepared from ethylene and one or more
C.sub.3-C.sub.12 alpha-olefins, such as 1-butene, 1-hexene and/or
1-octene.
[0046] The plastic materials of the various components of the solar
heat exchange panel may in each case independently and optionally
include a reinforcing material selected, for example, from glass
fibers, glass beads, carbon fibers, metal flakes, metal fibers,
polyamide fibers (e.g., KEVLAR polyamide fibers), cellulosic
fibers, nanoparticulate clays, talc and mixtures thereof. If
present, the reinforcing material is typically present in a
reinforcing amount, e.g., in an amount of from 5 percent by weight
to 60 or 70 percent by weight, based on the total weight of the
component (i.e., the sum of the weight of the plastic material and
the reinforcing material).
[0047] Fibers are typically present in the plastic components of
the heat exchange panel in amounts independently from 5 to 70
percent by weight, 10 to 60 percent by weight, or 30 to 50 percent
by weight (e.g., 40 percent by weight), based on the total weight
of the plastic component (i.e., the weight of the plastic material,
the fiber and any additives). Accordingly, the plastic components
of the heat exchange panel may each independently include fibers in
amounts of from 5 to 70 percent by weight, 10 to 60 percent by
weight, or 30 to 50 percent by weight (e.g., 40 percent by weight),
based on the total weight of the particular component.
[0048] The fibers may have a wide range of diameters. Typically,
the fibers have diameters of from 1 to 20 micrometers, or more
typically from 1 to 9 micrometers. Generally, each fiber comprises
a bundle of individual filaments (or monofilaments). Typically,
each fiber is composed of a bundle of 10,000 to 20,000 individual
filaments.
[0049] In addition or alternatively to reinforcing material(s), the
plastic components of the solar heat exchange panel may in each
case independently and optionally further include one or more
additives. Additives that may be present in the plastic components
include, but are not limited to, antioxidants, colorants, e.g.,
pigments and/or dyes, mold release agents, fillers, e.g., calcium
carbonate, ultraviolet light absorbers, fire retardants and
mixtures thereof. Additives may be present in the plastic material
of each plastic component in functionally sufficient amounts, e.g.,
in amounts independently from 0.1 percent by weight to 10 percent
by weight, based on the total weight of the particular plastic
component.
[0050] Alternatively, the molded plastic components (e.g., the
lower and upper plates) of the heat exchange panel of the present
invention may be prepared by a sheetless thermoforming process, in
which a heated sheet of thermoplastic material is formed (e.g.,
from an extruder coupled to a sheet die) and then vacuum drawn over
the internal surfaces of a mold portion, while the extruded sheet
is still thermoformable (and before it cools to a
non-thermoformable temperature). After cooling to a
non-thermoformable temperature, the molded article (e.g., in the
form of the lower plate or upper plate) is removed from the mold
portion, and typically subjected to post-molding operations, such
as joining the molded lower plate and molded upper plate together.
The heat exchange panel and the various components thereof may be
prepared by the sheetless thermoforming processes as described, for
example, in U.S. Pat. Nos. 7,955,550 and 7,842,225.
[0051] In one embodiment, the lower plate is a substantially
unitary lower plate molded from a first plastic material, and the
upper plate is a substantially unitary upper plate molded from a
second plastic material, in which the first and the second plastic
materials are each independently selected from thermoplastic
materials, thermoset plastic materials and combinations thereof, as
discussed previously herein. Further to this embodiment, the upper
plate is substantially transparent to infrared radiation, the lower
plate is substantially optically opaque, and the interior surface
of the lower plate absorbs infrared radiation.
[0052] The heat exchange panel of the present invention may have
any suitable shape and dimensions. For example, the heat exchange
panel may have a generally circular or oval shape, a polygonal
shape (e.g., triangular, rectangular, pentagonal, hexagonal,
heptagonal, octagonal shapes, etc.), an irregular shape (e.g., so
as to fit around another structure, such as a structural beam or
chimney), or any combination thereof. More generally, the heat
exchange panel may be a substantially flat heat exchange panel (as
depicted in the drawings), or a non-flat (e.g., arcuate) heat
exchange panel (not depicted). A non-flat heat exchange panel may,
for example, be used to fittingly and securely rest over the apex
of a gabled roof structure.
[0053] The heat exchange panel of the present invention may be used
to absorb thermal energy from any suitable source of thermal
energy, such as: a source of radiant thermal energy (e.g., infrared
radiation from the sun); or a source of convective thermal energy,
such as a fluid heat sink or source (e.g., a pool of heated liquid,
such as water, or stream of heated gas, such as air). In the case
of a source of radiant thermal energy, the heat exchange panel is
typically oriented so as to expose the exterior surfaces of the
upper plate and the upper plate extensions to the source of radiant
thermal energy, such as the sun. The radiant thermal energy is
transferred primarily through the upper plate extensions (and to a
lesser extent also through the exterior surfaces of the upper
plate), and into the fluid (e.g., a heat exchange fluid) passing
through the upper plate extension passages and underlying channels.
The heated fluid upon exiting the heat exchange panel may be used
directly (e.g., in the case of a shower), or indirectly, e.g., to
heat another fluid, such as water or air, in which case the fluid
may be described as a heat exchange fluid. When used to absorb
radiant thermal energy from the sun, the heat exchange panel may be
described as a solar heat exchange panel.
[0054] Alternatively, the heat exchange panel of the present
invention may itself be used as a source of thermal energy. For
example, a separately heated fluid may be passed through the
interior volume of the heat exchange panel, resulting in thermal
energy being transferred out of (rather than into) the upper plate
extensions and into a separate medium, such as a gas (e.g., air) or
a liquid (e.g., water). The separately heated fluid may be heated
in and provided by one or more separate heat exchange panels
according to the present invention that are set up so as to absorb
thermal energy from another source of thermal energy (e.g., the
sun), and which are in fluid communication with the heat exchange
panel that is itself acting as a source of thermal energy.
[0055] The present invention has been described with reference to
specific details of particular embodiments thereof. It is not
intended that such details be regarded as limitations upon the
scope of the invention except insofar as and to the extent that
they are included in the accompanying claims.
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