Note: Descriptions are shown in the official language in which they were submitted.
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TITLE
Solar Air Heater Collector
BACKGROUND
[0001] Solar thermal collector uses the solar power directly to heat a
fluid in
view of heating partially or completely a building such as a commercial
building.
[0002] Solar hot water heat collectors include pipes having water therein
that
is heated in the collector by solar radiation. A network of pipes is
connected to the collector and extends throughout the building to heat
the building.
[0003] A drawback of such system is that it requires expensive and complex
equipment to transfer the heat from the collector to the building. Also,
such systems imply operational costs, maintenance, etc.
[0004] Solar air heater collectors are usually simpler in that they do
require
less expensive and less complicated equipments. However, they are
usually still relatively complex in constructions and are therefore costly
to manufacture.
[0005] The installation of many solar air heater collectors to get a more
powerful solar heating system usually requires a complex and
expensive duct work that make the overall system less efficient.
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SUMMARY
[0006] An object of illustrative embodiments herein is therefore to provide
an
improved solar air heater collector.
[0007] Another object of illustrative embodiments herein is to provide such
an improved solar air heater collector which is relatively simple in
construction.
[0008] A further object of illustrative embodiments herein is to provide a
solar
air heater collector that can be connected in series to create a large
solar air heater system made of one or many solar air heater
collectors. Such a solar air heater collector is easy and fast to install,
relatively less expensive and more efficient than current solar
collectors on the market.
[0009] More specifically, in accordance with a first illustrative
embodiment,
there is provided a solar air heater collector for mounting on or beside
a building having an interior, the solar air heater collector comprising:
[0010] a cover layer for transmitting solar radiation and for protecting
the
internal layers from adverse weather; the cover layer including a
transparent sheet with or without an anti-reflection layer made of a
material having a high transmission at wavelengths within the solar
spectrum;
[0011] an absorber layer for collecting solar radiation; the absorber layer
including a sheet coated with a material having a high absorbance at
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the wavelengths within the solar spectrum and a low emittance in
wavelengths corresponding to a black body spectrum; a heat transfer
layer for transferring the collected solar radiation absorbed by the
absorber layer to an air fluid; the heat transfer layer including a
corrugated metal sheet mounted between the absorber and back
layers thereto; the heat transfer layer keeping a space out between
the absorber layer and back layer and creating a plurality of parallel
air channels; each of the plurality of parallel air channels having first
and second ends in fluid communication with respectively the air
intake and air outlet for guiding the air there between; the heat
transfer layer being further for receiving heat from the absorber layer
and for using the heat for heating the air fluid circulating in the air
channels from the air intake to the air outlet;
[0012] a back layer including a flat metal sheet; the back layer being
fixed to
the back of the heat transfer layer for closing the plurality of parallel
air channels created by the heat transfer layer;
[0013] a frame layer including profiles for maintain the cover layer and
the
insulation layer together, for mounting the solar air heater collector,
for protecting the inside of the solar air heater collector from the
adverse weather and for creating first and second air ducts between
the back and insulation layers; the first air duct being defined by the
air intake and it is connectable to another solar air heater collector or
to the building by an air intake hole; the second duct is defined by the
air outlet and is connectable to another solar air heater collector or to
the building by an air outlet hole;
[0014] an insulation layer including a sheet of insulating material for
decreasing the heat losses by the back of the solar air heater collector,
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for closing the two air ducts created by the frame layer and the back
layer and for protecting the internal layers from adverse weather.
[0015] According to a more specific embodiment, the four (4) sides of the
absorber sheet are bent for creating a space out between the
absorber layer and the cover layer.
[0016] A solar air heater collector according to an embodiment of the
present
invention allows achieving high heat transfer efficiency between the
solar radiations and the air to heat.
[0017] The expression "building" is not to be limited herein in any way and
should be construed broadly so as to include any construction that
includes walls and a roof, together defining a closed volume.
[0018] Other objects, advantages and features of a solar air heater
collector
will become more apparent upon reading the following non restrictive
description of embodiments thereof, given by way of example only
with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0001] In the appended drawings:
[0019] Figure 1 is a perspective view of a solar air heater system made of
three (3) solar air heater collectors connected in series according to
an illustrative embodiment; the collectors being illustrated mounted to
the exterior wall of a building, such as a commercial building;
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Figure 2 is an isolated perspective view of the three (3) solar collectors
from
Figure 1; the collectors being shown without theirs cover and absorber
layers;
[0020] Figure 3 is an exploded perspective of the cover, absorber, heat
transfer, back, frame and insulation layers of the collectors from
Figure 1; and
[0021] Figures 4 and 5 are respectively front and side cross sectional view
of
the cover, absorber, heat transfer, back, frame, and insulation layers
of the collectors from Figure 1, illustrating the assembly of the six
layers.
DETAILED DESCRIPTION
[0022] In the following description, similar features in the drawings have
been
given similar reference numerals, and in order not to weigh down the
figures, some elements are not referred to in some figures if they were
already identified in a precedent figure.
[0023] The use of the word "a" or "an" when used in conjunction with the
term
"comprising" in the claims and/or the specification may mean "one",
but it is also consistent with the meaning of "one or more", "at least
one", and "one or more than one". Similarly, the word "another' may
mean at least a second or more.
[0023] As used in this specification and claim(s), the words "comprising"
(and
any form of comprising, such as "comprise" and "comprises"), "having"
(and any form of having, such as "have" and "has"), "including" (and
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any form of including, such as "include" and "includes") or "containing"
(and any form of containing, such as "contain" and "contains"), are
inclusive or open-ended and do not exclude additional, un-recited
elements.
[0024] A solar air heater system according to a first illustrative
embodiment
will now be described with reference to Figures 1 to 3. While this solar
air heater system is made of three (3) solar air heater collectors, it is
not limited to such number and can be made of one (1) or another
number of solar air heater collectors.
[0025] VVith reference more specifically to Figure 1, the solar air heater
collectors 10, 11 and 12 are intended to be mounted to the exterior
wall 21, to the roof (not shown) or on a side wall 21 of a building 20.
As will be described hereinbelow in more detail, the collectors 10-12
receive energy from the sun and that energy is used by the collectors
10-12 to heat air circulating therein. For that purpose, two holes (not
shown) are provided in the wall 21, which are registered with
corresponding air intake hole 40 of the collector 12 and air outlet
hole 41 of the collector 10 (see on Figure 2). A fan (not shown) or
another device provided for a similar purpose is provided to force
relatively cool air from the interior of the building 20 to enter the
collector 12 via its air intake hole 40, to circulate within the collectors
12, 11 and 10 to be heated as will be explained hereinbelow and to
exit through the outlet hole 41 of the collector 10 hotter than it entered
the collector 12.
[0026] The solar air heater collectors 10, 11 and 12 will now be described
in
more detail with reference to Figures 1 to 5.
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[0027] The solar air heater collectors 10, 11 and 12 comprise a cover
layer 30 including glass sheet 30-1 for transmitting solar radiation
and for protecting the internal layers from adverse weather conditions,
a absorber layer 31 for collecting solar radiation, and a back layer 33
including a metal sheet 33-1, a heat transfer layer 32 mounted
between the absorber and back layers 31 and 33 thereto and
including corrugated metal sheets 32-1. The metal sheets 32-1 bias
the absorber layer 31 from the back layer 33 and define a plurality of
parallel air channels 60 therebetween.
[0028] The solar air heater collectors 10, 11 and 12 further comprise a
frame
layer 34, including two (2) short side profiles 34-3 (or 34-5) and 34-4
(or 34-6), a long top profile 34-2, a long bottom profile 34-1 for
maintaining the cover layer 30 and the insulation layer 35 together, for
attaching the solar air heater collector on a building 20, for protecting
the inside of the solar air heater collector from the bad weather.
[0029] A splitter profile 34-7 attached to back layer 33 and the insulation
layer 35 splits the space between these two (2) layers for creating
two (2) parallel air channels. One air channel is defined by the air
intake duct 42 and the other is the air outlet duct 43.
[0030] The cover, absorber, back, heat transfer and insulation layers 30,
31,
32, 33, 34 and 35 and the resulting collectors 10, 11 and 12 are
generally rectangular.
[0031] The cover layer 30 includes a sheet made of a material capable of
withstanding high heat, such as a low iron rolled glass 30-1, which is
made with a material having a high transmission at wavelengths within
the solar spectrum and a low transmission in the wavelengths
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corresponding to a black body spectrum and low reflection surfaces
at wavelengths within the solar spectrum. Examples of such glass
having the above-mentioned properties include: low iron rolled glass
SINATM and SINA TT-rm from Interfloat. According to the first
embodiment, the thickness of the glass sheet is between about
3.2 mm and 4 mm.
[0032] The cover layer 30 is not limited to the above described embodiments
and is capable of alternatives. For example, the sheet can have
another thickness. It can include another glass, a composite material,
TeflonTm, etc. It can be etched or coated with any material capable of
transmitting more than 90 percent of solar radiation.
[0033] The absorber layer 31 includes a sheet made of a material capable of
withstanding high heat, such as a metal, which is coated with a
material having a high absorbance at wavelengths within the solar
spectrum and a low emittance in the wavelengths corresponding to a
black body spectrum. Examples of such coated metal having the
above-mentioned properties include: eta plus_aITM from Bluetec and
TiNOX energy CuTM from Almeco Tinox. The thickness of the metal
sheet is for example between about 0.2 mm and 0.5 mm.
[0034] The absorber layer 31 is not limited to the above described
embodiments and is capable of alternatives. For example, the sheet
31-1 can have another thickness. It can include another metal, a
composite material, TeflonTm, etc. It can be coated with any material
capable of absorbing more than 80 percent of solar radiation and
having an emittance of less than 20 percent of the wavelengths
corresponding to a black body spectrum.
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[0035] According to the first illustrative embodiment, the
absorber layer 31 is
coated with a material absorbing more than 92 percent of solar
radiation and having an emittance of less than 8 percent of the
wavelengths corresponding to a black body spectrum.
[0036] The four (4) sides of the absorber sheet 31 are bent
for creating a
space out between the absorber layer and the cover layer 30. The
absorber layer 31, is attached and sealed to the cover layer 30 for
creating an air tight spaced out, using a high temperature resistant
silicone sealant 71 (figure 4- 5) or by any soldering, welding, sealing
or fastening technique.
[0037] The sheet 33-1 of the back layer 33 is preferably
made of a metal such
as aluminum or copper, but can also be made of another metal or
material capable of withstanding high temperatures. Example of such
other material includes ceramics, refractory materials, composite
materials, etc. The thickness of the sheet 33-1 can be for example
between about 0.05 mm and 0.2 mm. According to another
embodiment, the sheet of the back layer 33 is thicker or thinner than
the sheet 33-1.
[0038] The heat transfer layer 32 includes one (1)
corrugated metal sheets
32-1 that is positioned between the absorber and back layers 31 and
33. The corrugated sheets 32-1 with the absorber and back layers
define a plurality of parallel channels 60 that extend along a direction
parallel to the shorter side 61 of the collectors 10, 11 and 12 that
extends from a bottom end which is registered with the air intake
channel 42 to the top end which is registered with the air outlet
channel 43.
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[0039] The corrugated sheet 32-1 of the transfer layer 32 is preferably
made
of a metal such as aluminum or copper, but can also be made of
another metal or material capable to support high temperature.
Example of such other material includes ceramics, refractory
materials, composite materials, etc. According to the first illustrative
embodiment, the thickness of the sheet 32-1 is between about
0.05 mm and 0.3 mm. According to another embodiment (not shown),
the corrugated sheet of the transfer layer 32 is thicker or thinner than
the sheet 32-1
[0040] The heat transfer layer 32 receives heat from the absorber
layer 31and uses at least a portion of that heat to heat the air that
circulates in the air channels 60 from the air intake channel 42 to the
air outlet channel 43.
[0041] Even though the heat transfer layer 32 according to the illustrative
embodiment is assembled from one (1) corrugated sheets, it can be
made of any number of corrugated sheets and of different shapes and
sizes. Also, according to a further embodiment (not shown), the
resulting channels 60 define a shape different than a straight line.
Also, the number, size and depth of the channels 60 may be different
than those illustrated.
[0042] Even though the heat transfer layer 32 according to the illustrative
embodiment includes corrugated sheets 32-1 to bias the absorber
layer 31 from the back layer 33 and to define air channels 60, a heat
transfer layer according to an embodiment of the present invention is
not limited to this embodiment. Another metal structure can be
provided to yield the above-described functionality.
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[0043] The absorber, the heat transfer and the back layers, 31, 32 and 33
are assembled together by using welding technique (see Figures 4
and 5). This can be achieved using a laser welder, an ultrasonic
welder, a micro arc welder, etc. Since these machines and
apparatuses are believed to be well-known in the art and since the
processes of welding are also believed to be well-known, these
processes and the previously listed machines will not be described
herein in more detail for concision purposes.
[0044] According to another embodiment (not shown), the absorber, the heat
transfer and the back layers 31, 32 and 33 are assembled together
using another method such as high temperature sealing, clinching,
fastening (using fasteners, etc.), or else.The frame layer 34 includes
five (5) profiles per collector from 34-1, 34-2, 34-3 or 34-5, 34-4 or
34-6 and 34-7 made of a material capable of maintaining, supporting
and protecting from adverse weather conditions all the layers as
aluminum. According to some embodiments, the thicknesses of the
profiles are between about 1 mm and 3 mm and the height of the
profiles are between 100mm to 400mm depending of the number of
solar air heater collector to be connected in series.
[0045] The frame layer 34 is not limited to the above described embodiments
and is capable of alternatives. For example, the profiles 34-1, 34-2,
34-3, 34-4, 34-5, 34-6 and 34-7 can have another thickness or height.
It can include another metal, a composite material, NYIOnTM, etc.
[0046] The profiles 34-1, 34-2, 34-3, 34-4, 34-5, 34-6 of the frame layer
34
are attached to the cover and insulation layers 30 and 35 by using
high temperature adhesive 70, 73, such as without limitations high
temperature silicone sealant (see Figure 4 and 5).
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[0047] According to another embodiment (not shown), the
profiles 34-1, 34-
2, 34-3, 34-4, 34-5, 34-6 of the frame layer 34 are attached to the
cover and the insulation layers 30 and 35 using another method such
as welding, clinching, fastening (using fasteners, etc.), or else.
[0048] The profile 34-7 of the frame layer 34 is attached
to the back and
insulation layers 33 and 35 therebetween by using high temperature
adhesive 74 as high temperature silicone sealant (see Figures 4
and 5).
[0049] According to another embodiment (not shown), the
profile 34-7 of the
frame layer 34 is attached to the back and the insulation layers 33
and 35 using another method such as welding, clinching, fastening
(using fasteners, etc.), or else.
[0050] The profiles 34-1 and 34-7 of the frame layer define
with the back and
the insulation layers, the air intake channel 42. The profiles 34-2 and
34-7 of the frame layer define with the back and the insulation layers
the air outlet channel 43.
[0051] The profiles 34-5 and 34-6 of the frame layer 34
have two (2)
rectangular holes 37 allowing the air fluid to pass between the solar
air collectors 10, 11 and 12. In a solar air heater system made of
two (2) or more solar air collectors in series the first collector to the
left 10 has one 34-3 profile with no hole and one 34-4 profile with
holes, the last collector to the right 12 has one profile 34-5 with holes
and one profile 34-6 with no hole. In a solar air heater system made
of three (3) or more solar air collectors in series, the collectors in the
middle have one 34-4 profile with holes and one 34-5 profile with
holes. Those holes allow the air intake channel 42 and the air outlet
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channel 43 of each solar air heater collector attached in series to be
connected together allowing the air fluid to run from one solar air
heater collector to another.
[0052] According to another embodiment (not shown), the
holes 37 in the
profile 34-5 and 34-6 of the frame layer 34 have any shape such as,
without limitations circular or oval.
[0053] The insulation layer 35 includes a sheet of
insulation material 35-1
made of a material having a low heat conduction capable of
withstanding high heat, protecting the back of the collector from
adverse weather as polyurethane aluminum laminated sheet.
According to some embodiments, the thicknesses of the sheet are
between about 25 mm and 75 mm. Examples of such insulation
material having the above-mentioned properties include: ApfoilTM from
John Manville and ThermaxTm from Dow Chemical.
[0054] The insulation layer 35 is not limited to the above
described
embodiments and is capable of alternatives. For example, the sheet
35-1 can have another thickness. It can include another insulation
material, a composite material, StyrofoamTM, etc. It can be laminated
with any material capable of protecting the internal of the collector
from adverse weather conditions.
[0055] The hole 40 is made through the insulation sheet 35-
1 and defines the
air intake. The air intake hole 40 is in the air intake channel 42 of
collector 12 (as shown in figure 2 and 3) or in the collector 10 (not
shown).
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[0056] The hole 41 made through the insulation sheet 35-1 defines the
outlet.
The outlet hole 41 is in the air outlet channel 43 of collector 10 (as
shown in figure 2 and 3) or in the collector 12 (not shown).
[0057] The holes 40 and 41 are in opposition. For example, if the hole 40
is
made in the left collector 10 then the hole 41 must be in the right
collector 12.
[0058] The holes 40 and 41 in the insulation layer 35 are circular in
shape.
As mentioned hereinabove, the hole 41 defines the air intake of the
collector 12 and the hole 42 defines the air outlet of the collector 10.
[0059] The diameter of the holes 40 and 41 may vary, depending for example
on the number of collectors connected in series. For examples, the
holes have a diameter between about 10 and 60 cm.
[0060] The holes 40 and 41 are not limited to the circular shape and can be
for example rectangular, or else.
[0061] In operation, a fan (not shown) is connected to either the air
intake
hole 40 or the air outlet hole 41 so as to force the air from the
building 20 to enter the collector 12 (see arrow 51 in Figure 2), to
circulate in the air intake channel 42 therein (see arrows 52 and 53),
in the corrugated sheet 32-1 (see arrow 54), in the air outlet channel
43 (see arrow 55,56 and 57), and then to exit the collector 10 (see
arrow 58) warmer than it was before its entry in the collector 12.
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[0062] Illustrated embodiments of a solar air heater collector are not
limited
to being rectangular in shape and can be oval, circular, square,
irregular, or else.
[0063] It is to be understood that the illustrated embodiments are not
limited
in their application to the details of construction and parts illustrated
in the accompanying drawings and described hereinabove. It is also
to be understood that the phraseology or terminology used herein is
for the purpose of description and not limitation.
