U.S. patent application number 12/155205 was filed with the patent office on 2009-01-29 for solar panel.
Invention is credited to Gordon Hogan.
Application Number | 20090025710 12/155205 |
Document ID | / |
Family ID | 40091227 |
Filed Date | 2009-01-29 |
United States Patent
Application |
20090025710 |
Kind Code |
A1 |
Hogan; Gordon |
January 29, 2009 |
Solar panel
Abstract
A solar panel includes a circumferential upstanding rim defining
a cavity therein. An insulating layer is mounted in the cavity and
extends substantially completely across the cavity. A metal
heat-exchanger sheet is overlaid onto the insulating layer and
substantially entirely covers said insulating layer. A
light-transmissive sheet overlays the heat exchanger sheet and is
mounted to the rim. An array of fluid transmission tubes are
mounted to the heat-exchanger sheet by welding closed of channels
in the sheet so as to tightly encase the tubes in the channels. The
fluid transmission tubes conduct a flow of heat-exchanger fluid in
a heat exchange circuit.
Inventors: |
Hogan; Gordon; (Sorrento,
CA) |
Correspondence
Address: |
Antony C. Edwards
P.O. Box 26020
Westbank
BC
V4T 2G3
CA
|
Family ID: |
40091227 |
Appl. No.: |
12/155205 |
Filed: |
May 30, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60932176 |
May 30, 2007 |
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Current U.S.
Class: |
126/652 |
Current CPC
Class: |
F24S 25/67 20180501;
F24S 2025/6012 20180501; Y02A 30/62 20180101; F24S 10/753 20180501;
Y02E 10/44 20130101; F24S 40/40 20180501; Y02E 10/47 20130101; Y02A
30/60 20180101; F24S 80/70 20180501; F24S 20/67 20180501; F24S
2025/6004 20180501; Y02B 10/20 20130101; F24S 80/30 20180501; F24S
2020/18 20180501; F24S 2025/601 20180501; F24S 2020/10
20180501 |
Class at
Publication: |
126/652 |
International
Class: |
F24J 2/50 20060101
F24J002/50 |
Claims
1. A solar panel comprising a frame having a circumferential
upstanding rim and defining a cavity therein, an insulating layer
mounted in said cavity and extending substantially completely
across said cavity so as to abut said rim substantially
contiguously around said rim, a heat-exchanger sheet made
substantially of collector sheet metal overlaid onto said
insulating layer and substantially entirely covering said
insulating layer, at least one light-passing sheet overlaying said
heat exchanger sheet and mounted to said rim at edges of said
light-passing sheet, an array of fluid transmission tubes mounted
to said heat-exchanger sheet, said fluid transmission tubes
conducting a flow of heat-exchanger fluid in a heat exchange
circuit, wherein said array of fluid transmission tubes is mounted
to, so as to lay substantially flush along, said heat-exchanger
sheet within a corresponding array of channels formed in said
heat-exchanger sheet, and wherein each channel in said array of
channels is wrapped snugly around each corresponding tube in said
array of fluid transmission tubes for direct metal-to-metal heat
transfer of heat from said heat-exchanger sheet to said array of
fluid transmission tubes, and wherein said each channel when so
wrapped forms a seam of adjacent folds in said heat-exchanger sheet
along upper edges of said each channel when formed into said snug
wrapping around said each corresponding tube, and wherein said seam
is welded closed with a weld thereby tightening closed said seam
and consequently tightening said snug wrapping.
2. The panel of claim 1 wherein said collector sheet metal is
aluminium sheet.
3. The panel of claim 2 wherein said edges are closely adjacent
along said seam.
4. The panel of claim 2 wherein said light-passing sheet is
maintained spaced above said heat-exchanger sheet so as to maintain
an air gap therebetween.
5. The panel of claim 1 wherein said collector sheet metal is
aluminium sheet and said array of tubes is a substantially parallel
array of tubes and wherein an inlet header and an outlet header are
mounted in fluid communication with said array of tubes at,
respectively, inlet and outlet ends of said array.
6. The panel of claim 5 wherein said inlet end of said array is at
an end adapted to be mounted elevated above said outlet end of said
array.
7. The panel of claim 6 wherein said inlet header is a hollow
member having an array of orifices each in fluid communication with
a corresponding tube of said array of tubes for simultaneous
metering of said fluid into each tube of said array of tubes, and
wherein said aluminium sheet is of a thickness less than or
substantially equal to 24 gauge, and wherein said thickness is
sufficient for said weld to be welded to said seam.
8. The panel of claim 1 wherein said light-passing sheet is a
plurality of glass sheets in a linear array mounted to said rim,
and wherein adjacent glass sheets in said linear array overlap
along their common edges.
9. The panel of claim 8 wherein said panel has an upper end and an
opposite lower end and wherein said upper end is adapted to be
elevated above said lower end, and wherein said overlap between
said adjacent glass sheets is a cascading overlap wherein a
lower-most edge of an upper sheet overlaps on top of an upper-most
edge of a lower sheet.
10. The panel of claim 9 wherein every said overlap between said
adjacent sheets is a said cascading overlap.
11. The panel of claim 9 wherein a first hooked member is mounted
in said overlap so as to support and mount said common edges to one
another.
12. The panel of claim 11 wherein said first hooked member forms a
common-edge receiving channel in a hook of said first hooked member
for receiving one of said common edges in said channel, and wherein
a planar flange portion of said hooked member is adhesively
mountable to another of said common edges.
13. The panel of claim 1 wherein a second hooked member is mounted
to said rim, and wherein said second hooked member has a hook
portion forming an edge receiving channel for mounting therein of
an edge of said light-passing sheet, and wherein said second hooked
member has a planar portion mounted to said rim.
14. The panel of claim 13 wherein said edge of said light-passing
sheet is adhesively mounted in said edge receiving channel.
15. The panel of claim 14 wherein said edge-receiving channel
extends, substantially entirely along a corresponding said edge of
said light-passing sheet.
16. The panel of claim 15 wherein said edge-receiving channel
extends completely along longitudinal edges of said rim.
17. The panel of claim 13 wherein a moisture deflecting cap is
mounted on said second hooked member to inhibit ingress of moisture
into said edge-receiving channel.
18. The panel of claim 13 wherein said panel is adapted for flush
mounting adjacent a second said panel by a pair of said second
hooked members mounted oppositely disposed along said rim so as to
oppositely dispose on said rim a corresponding pair of said edge
receiving channels.
19. The panel of claim 18 further comprising fasteners mounting
said pair of second hooked members to an upper edge of said
rim.
20. The panel of claim 13 further comprising fasteners mounting
said second hooked member to an upper edge of said rim.
21. The panel of claim 13 further comprising a drip gutter mounted
between said second hooked member and an upper edge of said
rim.
22. The panel of claim 21 further comprising a moisture impervious
flexible sheet mounted sandwiched between said drip gutter and said
upper edge of said rim.
23. The panel of claim 22 wherein said flexible sheet extends from
said rim under said insulating layer.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional
Patent Application No. 60/932,176 filed May 30, 2007 entitled Solar
Panel.
FIELD OF THE INVENTION
[0002] This invention relates to solar collection panel
construction and in particular to cost effective and highly
efficient solar energy collector panels constructed in a scalable
manner as a single integrated unit onto the roof or other support
structure.
BACKGROUND OF THE INVENTION
[0003] It is known that when making solar collectors based on heat
transfer to a fluid, that a sheet or thermally conductive material
that readily absorbs solar energy is placed in thermal contact with
fluid carrying elements, tube or pipe to transfer the absorbed
solar energy to the fluid which is ultimately pumped and stored for
use in heating or power generation applications. The construction
of the solar collector often includes a framework or housing which
can be mounted to a structure such as a building roof. The housing
typically insulates the solar panel from the surrounding
environment and generally has a optically clear cover such as a
glass panel which allows a substantial portion of the solar energy
impinging on it to pass through to be absorbed by the underlying
sheet of the solar collector. The construction of the solar
collector sheet and the housing enclosing it can vary greatly in
both cost and efficiency.
[0004] Applicant is aware of patents regarding solar collector
design and housing such as U.S. Pat. No. 5,431,149 titled "Solar
energy collector", issued to Fossum, et al. on Jul. 11, 1995.
Fossum teaches a large rectangular solar heat absorber which
includes a plurality of identical rectangular heat absorbing panels
which, when assembled in side by side and end to end relationship
will form a total heat absorbing surface area of the desired
dimensions, with each panel comprising a rectangular heat absorbing
plate having a top surface to receive incident solar radiation, a
black body radiation coating on the top surface; and one or more
pipes secured in heat transferring relation to the bottom surface
of said heat absorbing plate; a rectangular frame dimensioned to
mount a number of panels in side by side and end to end relation; a
panel of glass covering the panels and having the property of
reflecting infrared radiation emitted by said black body coating;
means for securing the glass cover to the frame; means connecting
the adjacent ends of said pipes to provide heat transfer fluid flow
paths extending the length of the end to end panels; header means
connected to the non-adjacent ends of said pipes for directing
fluid flow through all of said heat transfer flow paths; pump means
for producing turbulent flow of heat transfer fluid through all of
said pipes; an inlet header connected to one end of a first set of
pipes providing a fluid flow path to said first set of pipes; an
outlet header connected to one end of a second set of pipes
providing a fluid flow path from said second set of pipes; said
inlet header and outlet header being on the same ends of said
panels with connecting means providing horizontally parallel fluid
flow paths; and header means directing fluid flow from said first
set of pipes to said second sets of pipes, said second set of pipes
having a fluid flow path in a direction opposite the fluid flow
path of said first set of pipes.
[0005] U.S. Pat. No. 4,201,193 titled "Solar energy absorbing roof"
issued to Ronc on May 6, 1980, teaches a solar roofing structure
combining the covering and waterproofing functions of a
conventional roof with the functions of a solar energy-collecting
panel, and which consists of a supporting base; a layer of
insulating material on said base; waterproofing cover of elastomers
and bitumen, the outer surface of which is covered on its upper
surface with mineral particles selected from the group consisting
of gravel, glass and ceramic particles; and means separate from
said waterproofing cover means defining circulation channels for a
liquid, in close contact with and below the waterproofing cover
means, and between said waterproofing cover and the insulating
material and in contact with each.
[0006] U.S. Pat. No. 4,172,311 titled "Process for manufacturing
solar collector panels" issued to Heyman on Oct. 30, 1979, teaches
a method for fabricating a lightweight economical solar energy
collector panel comprising the steps of: building a solar collector
by inverting the outer frame having an inwardly protruding top
flange defining a radiation-receiving opening, thereby upwardly
exposing the underside of the top flange; positioning on the
upwardly exposed underside of the top flange a translucent glass or
plastic layer substantially transparent to solar radiation spanning
the outer frame across the opening beneath the top flange; placing
on the upwardly exposed underside of the translucent layer a spacer
partition means underlying the translucent layer, and having a
plurality of rigid upright support wall portions spanning the outer
frame and juxtaposed to the translucent layer; forming a
manifold-connected plurality of heat-conductive fluid conduit means
shaped and dimensioned for underlying the spacer partition means;
forming a temporary array comprising a thin metallic foil sheet
foldably formed into cylindrical channel heat-transmitting portions
which all embrace the fluid conduit means, and which are
contiguously foldably joined by substantially flat heat-receiving
portions shaped for extending across the opening beneath the spacer
partition, exposed to solar radiation entering the opening;
inverting and positioning the temporarily assembled metallic foil
sheet and conduit array on the exposed underside of the upright
support wall portions of the spacer partition means with the
conduit array protruding into the interior region of the outer
frame away from the spacer partition means; and foaming in place a
polymer foam back directly in contact with the temporarily
assembled metallic foil sheet and fluid conduit array, spanning and
substantially filling the remaining space within the outer frame
and thereby permanently anchoring the foregoing assembled
components into an interconnected panel unit.
[0007] U.S. Pat. No. 4,164,935 titled "Solar heating panels" issued
to Marles, et al. on Aug. 21, 1979, teaches a solar heating panel
comprising a plurality of cylindrical tubes for carrying a liquid
to be heated and an absorber plate for absorbing solar radiation
falling thereon, the absorber plate including a plurality of rigid
plate sections each having at one edge an outwardly-facing concave
substantially semi-cylindrical portion, the concave surface of the
semi-cylindrical portion having the same radius of curvature as the
outer circumferential surface of one of the cylindrical tubes, and
clamping means engaging the convex outer surfaces of the
semi-cylindrical portions on two adjacent plate sections and
thereby clamping a cylindrical tube with its outer surface in
heat-conducting contact with the concave surfaces of said
semi-cylindrical portions, each of the plates of said plurality of
plate sections being shaped at an opposite edge which is parallel
to the said one edge such that the said opposite edge faces towards
the said one edge thereby defining a channel in the plate section
within which channel a similar opposite edge of another plate
section is slidingly engaged in a manner which detachably
interlocks the opposite edges but permits expansion of the plate
sections relative to one another.
[0008] U.S. Pat. No. 4,072,262 titled "Method of fabricating a
solar heating unit" issued to Godrick, et al. on Feb. 7, 1978,
teaches a process for fabricating a solar heating unit for heating
fluids where the process consists of: placing a thin, soft,
annealed sheet having a good thermal conductivity characteristic in
conformal relation to a grooved surface of a self-supporting,
thermally conductive planar plate, assembling a plurality of tubes
in a spaced apart planar relation, the spacing between the tubes
equal to the spacing between said grooves, and the contour of the
grooves substantially conforming to a portion of the contour of the
tubes, connecting headers in a fluid-tight connection to the tubes
to provide fluid flow paths between said headers and the tubes,
applying a thermally conductive paste adhesive along the conformal
portion of the tubes, and positioning the assembled elements in an
aligned relation to the grooves in the plate with the conformal
portion abutting the thin sheet, and pressing the tubes against
said sheet with sufficient pressure and temperature to creep form
the sheet around the attachment portion of the tubes, and to
simultaneously melt the paste adhesive to provide a good thermally
conductive bond between the elements and the sheet.
[0009] U.S. Pat. No. 4,011,856 titled "Solar fluid heater" issued
to Gallagher on Mar. 15, 1977, teaches a solar energy fluid heater
made of an open housing having rigid bottom and side panels; a
plurality of abutting solar panels for collecting solar energy
positioned within the housing, each having an upper surface
positioned below the opening in the housing for collecting solar
energy, an open circular channel formed in the center portion of
each panel having an opening smaller than the diameter of the
channel along the longitudinal center of the solar panel, with the
channel being below the opening and the upper surface and the
portions of the upper surface adjacent each side of the opening
having a linear downward slope; a conduit member positioned within
the channel having a diameter greater than the relaxed diameter of
the channel and a length sufficiently long to extend from each end
of the solar panel; header members one connecting each adjacent end
of the conduit and extending to the exterior of the collector
housing; a number of support members spaced apart along the bottom
panel of the housing for spacing the solar panels from the bottom
panel; insulation is placed between the solar panels and the bottom
of the housing; at least one panel of translucent material is
placed above said upper surface of the solar panel is sealed to the
side panels forming an enclosure for the opening of the housing;
and pressure applying means for securing the edges of the adjacent
panels in firm physical contact to ensure heat transfer between the
adjacent panels by thermal conduction. The solar heat collector
would typically be coated with a solar energy absorbent material on
its upper exposed surface. In addition the fluid carrying conduit
having a greater diameter than that of the relaxed channel diameter
for securing the conduit within the channel by spring tension; and
screw anchors for securing the edges of the panel in firm physical
position to maintain said mechanical force between said channel and
conduit as the temperature of the panel increases to insure heat
transfer between said panel and conduit by conduction.
SUMMARY OF THE INVENTION
[0010] The present invention serves to collect solar energy for the
purposes of heating and/or generating electricity for various
purposes. The present invention uses a modular sheet metal surface
with imbedded tubing to conduct thermal energy absorbed by a high
absorption low emissivity painted surface. After pressing the tubes
into the sheet metal or otherwise forming the metal snugly around
the tubes, the sheet metal surface is formed to be welded to itself
along the top of the tubes, thereby securely capturing the tubes
and maintaining direct thermal conductivity between the sheet
metal, the tube, and the fluid or gas flowing through the tubes
into the solar collector circuit and reservoir circuit without the
need for thermally conductive filler or adhesive, etc., clips, or
other means found in the prior art for adhering a collector sheet
to a fluid conducting tube. The collector modules can be scaled in
length and width to increase solar collection coverage over areas
of various size.
[0011] The solar collector can be configured for liquid coolant or
phase change materials such as liquid/gas refrigerants, with the
potential for a broad range of operating pressures. The solar
collector may be housed in a roof mount or stand-alone
configuration. A glazing profile, used in conjunction with a
rubbery for example silicon extrusion, provides an efficient method
of constructing the solar collector of the present invention.
[0012] The solar collector is built onto the supporting structure
by laying down EPDM (Ethylene Propylene Diene Monomer) roofing
rubber membrane and then fastening a framework to the support,
followed by insulation, aluminum foil, a black anodized or painted
aluminum sheet that has been folded or otherwise formed about a
plurality of copper tubes and welded along the fold seam along the
top of the tubes so as to form an contiguous surface, with an air
gap and a pane of glass.
[0013] In summary, the solar panel according to the present
invention may be characterized in one aspect as including a
circumferential upstanding rim and defining a cavity therein, an
insulating layer mounted in the cavity and extending substantially
completely across the cavity so as to abut the rim substantially
contiguously around the rim, a heat-exchanger sheet made
substantially of collector sheet metal overlaid onto the insulating
layer and substantially entirely covering said insulating layer, at
least one light-passing sheet overlaying the heat exchanger sheet
and mounted to the rim at edges of the light-passing sheet, and an
array of fluid transmission tubes mounted to the heat-exchanger
sheet, the fluid transmission tubes conducting a flow of
heat-exchanger fluid in a heat exchange circuit. The array of fluid
transmission tubes are mounted to, so as to lay substantially flush
along, the heat-exchanger sheet within a corresponding array of
channels formed in the heat-exchanger sheet.
[0014] Each channel in the array of channels is wrapped snugly
around each corresponding tube in the array of fluid transmission
tubes for direct metal-to-metal heat transfer of heat from the
heat-exchanger sheet to the array of fluid transmission tubes. Each
channel when so wrapped forms a seam of adjacent, for example
closely adjacent, folds in the heat-exchanger sheet along upper
edges of each channel when formed into the snug wrapping around
each corresponding tube. The seam is welded closed with a weld
thereby tightening closed the seam as the weld and channel cools,
and consequently tightening the snug wrapping of each channel
around its corresponding tube.
[0015] Advantageously, the collector sheet metal is aluminium
sheet, and the light-passing sheet, for example of glass, is
maintained spaced above the heat-exchanger sheet so as to maintain
an air gap therebetween. The aluminium sheet may be of a thickness
less than or substantially equal to 24 gauge, wherein the thickness
is sufficient for the weld to be welded to the seam.
[0016] In one embodiment the array of tubes is a substantially
parallel array of tubes and wherein an inlet header and an outlet
header are mounted in fluid communication with the array of tubes
at, respectively, inlet and outlet ends of the array. The inlet end
of the array is at an end adapted to be mounted elevated above the
outlet end of the array, wherein the inlet header is a hollow
member having an array of orifices each in fluid communication with
a corresponding tube of the array of tubes for simultaneous
metering of the fluid into each tube of the array of tubes.
[0017] In a further embodiment, the light-passing sheet is a
plurality of glass sheets in a linear array mounted to the rim,
wherein adjacent glass sheets in the linear array overlap along
their common edges in the fashion of a shingled roof. In such an
embodiment, the panel has an upper end and an opposite lower end
and the upper end is adapted to be elevated above the lower end, so
that the overlap between the adjacent glass sheets is a cascading
overlap wherein a lower-most edge of an upper sheet overlaps on top
of an upper-most edge of a lower sheet. For example, every overlap
between adjacent sheets may be a cascading overlap.
[0018] In the embodiment taught herein, which is not intended to be
limiting, a first hooked member is mounted in the overlap, where in
one example the overlap is a laterally extending seam, so as to
support and mount the common edges of the glass sheets to one
another. The first hooked member forms a common-edge receiving
channel in a hook of the first hooked member for receiving one of
the common edges in the channel. A planar flange portion of the
hooked member is adhesively mountable to another of the common
edges.
[0019] In the embodiment taught herein, which is again not intended
to be limiting, a second hooked member is mounted to the rim for
example along longitudinal edges or seams. The second hooked member
has a hook portion forming an edge receiving channel for mounting
therein of an edge of the light-passing sheet. The second hooked
member has a planar portion mounted to the rim. The edge of the
light-passing sheet is adhesively mounted in the edge receiving
channel, substantially entirely along a corresponding edge of the
light-passing sheet. For example, the edge-receiving channel
extends completely along longitudinal edges of the rim.
Advantageously, a moisture deflecting cap may be mounted on the
second hooked member to inhibit ingress of moisture into the
edge-receiving channel.
[0020] As also taught herein, each panel may be adapted for flush
mounting adjacent a second panel by a pair of second hooked members
mounted oppositely disposed along the rim so as to oppositely
dispose on the rim a corresponding pair of edge receiving channels.
Fasteners mount the pair of second hooked members to an upper edge
of the rim. A drip gutter may be mounted between the second hooked
member and the upper edge of the rim. A moisture impervious
flexible sheet may be mounted sandwiched between the drip gutter
and the upper edge of the rim. The flexible sheet may extend from
said rim under said insulating layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In the drawings similar characters of reference denote
corresponding parts in each view, and wherein:
[0022] FIG. 1 is, in front plan view, an embodiment of the solar
panel of the present invention with two ganged tube embedded sheet
collectors behind a single pane of glass.
[0023] FIG. 2 is, in perspective cutaway view, an embodiment of the
solar panel of the present invention showing the preferred
construction for installation of the solar panel on a sloped
roof.
[0024] FIG. 2a is a perspective cutaway detail view showing a close
up cutaway of the embodiment of the solar panel of FIG. 2, showing
the preferred construction for installation of the solar panel on a
sloped roof.
[0025] FIG. 3 is, in front plan view, an embodiment of the solar
panel of the present invention with three ganged tube embedded
sheet collectors and a short collector behind two overlapping panes
of glass, demonstrating the scalability of the present
invention.
[0026] FIG. 4 is, in plan view, an embodiment of the tube embedded
sheet collector of the present invention.
[0027] FIG. 4a is, in front sectioned perspective view, the
embodiment of the tube embedded sheet collector of FIG. 4 enlarged
to show more detail.
[0028] FIG. 4b is, in front sectioned detailed perspective view,
the embodiment of the tube embedded sheet collector of FIG. 4a
showing in detail the press fit of the tube in the metal sheet and
the welded seam.
[0029] FIG. 5 is, in front perspective view, two tube embedded
sheet collectors being joined together.
[0030] FIG. 6 is, in front perspective view, the embodiment of FIG.
3.
[0031] FIG. 6a is, in side detailed section view, one embodiment of
the overlap of the glass on the vertically scaled up solar panel of
the present invention.
[0032] FIG. 6b is, in end cross sectional view along line 6a-6a in
FIG. 9, the overlap of the glazing strips supporting the
overlapping panes of glass.
[0033] FIG. 7 is, in front sectioned view, shows the cross section
of a glazing securement method.
[0034] FIG. 8 is, in front perspective view, a solar collector
panel of the present invention configured for refrigerant operation
where the refrigerant is metered into the solar collector tubes
near or at the top of the collector.
[0035] FIGS. 8a and 8b are, in front detailed perspective view
enlarged from FIG. 8, metering headers of the refrigerant based
embodiment of the solar collector of FIG. 8.
[0036] FIG. 9 is, in plan view, a solar collector array of the
present invention that has been scaled out both vertically and
transversely for mounting on a pitched roof, and customized in
profile along its upper edge to match a gable roof line.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0037] The present invention includes a solar collector panel array
1 in which the active element or collector panel 3 includes a
single thin sheet 15 of thermally conductive material such as but
not limited to aluminum or other heat-conductive sheet metal which
may be welded (herein collectively referred to as collector sheet
metal), that has had fluid conducting metal (for example copper)
tubes 4 pressed into or otherwise positioned so as to lie in
channels 15b in sheet 15 so that the sheet 15 conformally encases
the tubes 4. The channels are closed by a weld W in welded seam 18,
best seen in FIG. 4b, where the opposed facing folds 15a in sheet
15 substantially meet or are closely adjacent after encircling the
tubes 4. The tubes 4 are typically made of copper, steel, or some
other suitable sized material capable of handling high pressures
for solar energy collection applications using fluids ranging from
water to liquid/vapor phase change refrigerant materials as would
be known to one skilled in the art. The thermally conductive metal
sheet 15 is typically coated on the upwardly or outwardly exposed
surface with a high solar radiation absorption and low infrared
emissivity paint as well known in the art.
[0038] Welding seam 18 closed aids in tightening the encasement of
channels 5b about tubes 4. In particular, during the welding
process the metal of sheet 15 adjacent the seam and channels 15b
are heated and expand. While so expanded if the channels 15b are
maintained and snugged around tubes 4 and folds 15a welded to one
another, then upon the metal of channels 15b cooling and
contracting, the channels 15b tighten so as to be closely clamped
in metal-to-metal contact around tubes 4. This then avoids the use
as seen in the prior art of clips, conductive adhesives/fillers,
or, if unsecured, the loosening of, and lessening of,
metal-to-metal contact in collector/tube interfaces due to
expansion and contraction as would be seen in some of the prior
art, leading in some cases perhaps to unwanted electrolysis between
the metals.
[0039] Thus in a preferred embodiment which is not intended to be
limiting, aluminum sheet 15 may be for example 24 of 22 gauge
aluminum sheet, or thinner if folds 15a can still be welded
together to tightly encase tubes 4 in channels 15b. Tubes 4 may be
copper tube having 1/4 inch inside diameter. The solar collector
according to the present invention may, as described below, be
quite long, for example 24 feet or more, and modularly constructed
of 4 foot-by-8 foot panels.
[0040] Thus, the solar collector of the present invention may
advantageously be constructed in a modular fashion by the
interconnecting of tubes 4 by the use of flared ends 16 that are
flared to a diameter that accepts the original outside diameter of
the exposed end of a corresponding tube 4. In this way more than
one module may be stacked or interconnected so as to mate the ends
of the tubes exposed between modules as illustrated in FIG. 5 to
create a larger solar collector 13 as shown in FIGS. 3 and 9.
Typically after the male ends 17 of the tubes of one solar
collector module are inserted into the female flared ends 16 of the
tubes of the next adjacent collector, the joints between the ends
of the tubes are heated and solder is applied to bond the tubes and
providing a sealed fluid path. In this way a solar panel 1 of
custom length can be made by joining one or more whole or part
modules 3 in series, creating a panel the same width as the
original module.
[0041] As shown in FIG. 8 and described above, welding seam 18
while the conformally encased tube 4 is pressed and held in
channels in sheet 15 results in a tensioned contact between the
channels in sheet 15 and tubes 4 resulting in a good thermal
connection between the two that will be maintained over the life of
the solar collector 3 in spite of thermal expansion and shrinkage.
The operation of pressing the tube into the sheet 15 where the
sheet is made of aluminum results in work hardening of the
aluminum, which further reduces the likelihood of it moving much
due to thermal expansion and contraction, thereby maintaining the
physical and thermal connectivity between the tube 4 and the sheet
15.
[0042] The collector panels 3 can be configured for either liquid
heat transfer fluid such as water or glycol, or refrigerant
coolants. One embodiment of the present invention may be
implemented for a gravity fed refrigerant based solar collector 22
without a pump in the circuit as shown in FIG. 8, where a metered
inlet header 25 can be located part way down from the top, or
alternatively such as header 29 at the top of the array such that
it is far enough below the condenser in the heat reservoir that the
liquid refrigerant has enough head to return to the solar collector
evaporator. Thus for example, where there is insufficient head to
supply a header 29 at the top of the array, a header 2t positioned
part-way down the array may be used.
[0043] Keeping in mind that the collection panel 1 is inclined as
it would be if mounted on a pitched roof or inclined for example
vertically on a stand, upper inlet header 29 is elevated above
lower header 30. In a liquid refrigerant embodiment example header
29 is metered as better seen in FIG. 8b so that liquid refrigerant
is introduced through metering ports 26 into tubes 4. The metered
header 25 better seen in FIG. 8a also introduces liquid refrigerant
through metering ports 26 into tubes 4. Metering ports 26 for the
liquid refrigerant embodiment may be for example conventional
refrigerant metering tubes (for example a #36 metering tube for a
24 foot long array) soldered into the header, where the upper
header may be a 3/8 inch pipe. In other words, the metering orifice
is essentially a pin-hole size, being of 1/16.sup.th inch or less.
in embodiments using for example water as the heat transfer fluid
the header would be for example 3/4 inch pipe with a 1/4 inch hole
feeding directly into tubes 4.
[0044] The refrigerant header 25 is located part-way down from the
top of the collector 22 such that refrigerant that flashes to gas
can rise to the top of the array 24 to be collected by the upper
header 29 and returned to the condensing heat exchanger in the heat
reservoir, while gravity draws the liquid refrigerant down into the
larger lower section 23 for solar heat absorption. The gas, and
maybe a small amount of liquid, is accumulated by lower header 30,
and circulated back to the condenser in the heat reservoir along
with the gas from the upper header 29. Lower header 30 may be
situated part way up the collector from the bottom for the gas
return of the refrigerant to the condenser in the heat reservoir.
In this implementation the bottom-most header 30 can simply act as
a liquid accumulator, for example when the sun is weak or at the
end of the day, or both, and pressure balancing passage between the
various solar tubes 4, with both ends of the header capped.
[0045] In the refrigerant embodiment of the present invention
refrigerant based heat exchange media is pumped to the inlet
metering valves 26, better seen in FIG. 8b, between the upper inlet
header 29 and the solar collector tubes 4. Gas and any left over
liquid refrigerant flows back to the condenser from the lower
header 30. The uppermost ends 4a of tubes 4 are capped or otherwise
sealed closed.
[0046] The injector orifice into each tube 4 is sized for the
length of the tube, allowing the refrigerant to evaporate as it
runs down the length of the tube under the force of gravity. This
allows, with the appropriate quantity of injected refrigerant, for
an even evaporation along the length of tube, that is along the
length of the collector, resulting in an even temperature along the
collector. This avoids a problem encountered by the applicant where
the liquid alcohol refrigerant would not flow above five feet
before the alcohol evaporated allowing the collector to get very
hot above the five foot levels. Thus using the solution to that
problem according to the present invention even long runs of tubes
4, that is, when a plurality of modular panel section are joined
together to form a long for example 20 foot or more length of
collector panel 1, the amount of refrigerant being injected from
the upper header may be adjusted to balance for the extra length of
evaporation occurring in the extra length of the tubes.
[0047] The solar collector panel 1 can be configured for roof top
installation or as a stand-alone unit. FIGS. 2 and 2a show cutaway
views of the roof top embodiment panel 6 of the solar panel 1,
where a layer of waterproof material such as EPDM (Ethylene
Propylene Diene Monomer) rubber sheet 7 is put on the existing
roofing structure sandwiching sheet 7, and then a wooden frame 8 is
fastened onto the existing roofing structure, and insulation 9 is
placed on the EPDM sheet 7 and within the frame 8, with a layer of
paper backed aluminum foil 9a placed on top of the insulation. The
EPDM sheet 7 is wrapped around the frame 8, terminating within the
enclosed frame work and overlapping the insulation 9 slightly.
[0048] The base edge 6a of panel 6 as seen in FIG. 2 and the
opposite top edge (not shown) may advantageously be constructed so
as to allow air transfer into and out of the panel to help
alleviate condensation. Consequently the base and top edges of the
panel are not sealed in the fashion of the side edges such as
illustrated in FIG. 2a. Rather, the top of the frame member is not
sealed with a J-clip 19, type 37 and silicon bead 32. Instead, the
edges of glass sheet 11 are siliconed directly down onto aluminum
flashing 31. Flashing 31 has for example a small upstanding lip 31a
against which the edge of the glass is rested. Silicon adhesive is
used between the underside of the edge of the glass sheet and the
top surface 31b of the flashing.
[0049] Solar collector modules 3 are placed into the framework 8 on
top of the insulation 9 complete with plumbed headers 29, 30 to
connect with the solar collection circuit. Oppositely disposed
glass-supporting channels 19a are provided by J-clips 19 (or other
channel members) which are installed over a C-shaped aluminum
profile which serves to catch drips, herein drip edge or drip
gutter 39. Drip gutter 39 is itself mounted down onto the EPDM
sheet 7 and frame 8 by screws 38. Sheets of glass 11 are retained
in channels 19a in J-clips 19. In order to facilitate lateral
edge-to-edge expansion of the solar collector array, the lower
flanges 19b of J-clips 19 extend horizontally outwardly, for
example so as to terminate flush with the edges of frame 8. Glass
sheets 11 may be 3 millimeter thickness glass. Channels 19a may
have a 1/4 inch gap to accommodate 1/8.sup.th inch foam tape 37 and
the 3 millimeter thick glass sheet 11. When the lower, inner flange
of C-clip 21 or flashing clip 36, as the case may be, is also
inserted under the upper flange of a J-clip 19, tape 37 is
compressed so that the edge of the glass is clamped in the J-clip
channel. The J-clip flanges and web may for example be 1/16.sup.th
inch thick.
[0050] Channels 19a serve to support the edges 11a of glass 11
sandwiched between the lower flanges 21a of a cap member such as
C-clip 21 and double-sided tape 37, such as double-sided foam
window glazing tape. The bottom surface of tape 37 is mounted to
the lower flanges 19b so that edges 11a of glass 11 rest on, and
are adhered to, the top surface of tape 37. Beads 32 of resilient
sealant adhesive such as glazing silicon are used to resiliently
seal tape 37 within channels 19a while providing for thermal
expansion and contraction of glass 11. Beads 32 and tape 37 are of
such diameter and durometry that the resting weight of the glass 11
only slightly compresses the bead and tape. C-shaped clips 21 when
mounted along the length of the top profile of J-clips 19 act on
glass 11 so as to urge the glass downwards onto the tape 37 and
beads 32, thereby slightly compressing the tape and beads,
resulting in a seal between the glass 11, the tape and beads, and
the lower flanges 19b of J-clips 19.
[0051] The roof mount configuration is very scalable by extending
the framework both vertically and horizontally. FIGS. 3 and 6 show
a single module width, and FIG. 9 a double module width solar
collector 1 of the present invention extended by cascading, that is
overlapping like a shingled roof, a number of full and partial
length solar collector modules 3. At some point the size of the
solar collector 1 will require glass 11 that is too large to be
handled in one piece. At this point more than one pane of glass is
thus called for. The panes of glass may be installed by the
following method: The lower-most pane 11a of glass 11 is silicon
adhered at its lower end onto flashing 31 mounted on EPDM sheet 7
on the lower end of Frame 8, where the flashing 31 is not sealed
onto the sheet 7 and the frame to allow air seepage.
[0052] As seen in FIG. 6a, a second, upper pane 11b of glass 11 has
a J-clip 19 mounted to its lower end, along its lower inside edge
using glazing adhesive 32' such as structural silicon glazing
adhesive. The J-clip 19 is mounted with its wider flange 19b
abutted against the lower inside edge of upper pane 11b, and is
oriented so that channel 19a is open downwardly so as to receive
therein the upper edge of lower pane 11a. The upper edge of lower
pane 11b mates into channel 19a against a resilient bead, member or
insert such as snake-like silicon gasket 20 inlaid along the length
of the base or web of channel 19a. Advantageously wide flange 19b
presents at least a one inch wide bearing surface for adhesion to
upper pane 11b. The second lower pane 11a thus overlaps under the
upper first pane 11b along overlap seam 3a.
[0053] FIG. 6b is illustrative of one way, not intending to be
limiting, to mount onto frame 8 the intersection as seen in FIG. 9
of lateral or horizontal over-lapped seams 31 with longitudinal or
vertical abutting seams 3b between adjacent panels 3. In
particular, the side edges of the overlapped portion (the one inch
overlap between upper and lower glass sheets 11b and 11a) are each
supported in, respectively, an upper J-clip 19 and a lower,
modified J-clip 19''. Thus upper glass sheet 11b is supported in
the upper J-clip 19 as taught with respect to the single layer
abutting seam of FIG. 7. The lower J-clip'' is modified to remove
the upper flange 19c while leaving the web of the J-clip and lower
flange 19b. Thus upper J-clip 19 may be overlapped onto lower
J-clip 19'' by, again, approximately one inch, without the upper
flange of lower J-clip 19'' interfering with the upper J-clip 19.
As seen in FIG. 6b, the J-clips 19' and corresponding adhesive 32'
stop short, that is, end laterally, before they interfere with the
J-clips 19, adhesive beads 32, etc. making up longitudinal seam 3b.
Again, as seen in FIG. 7, a fastener such as screw 38 fastens the
J-clips 19 in seam 3b down onto frame 8. In one embodiment drip
gutters 39 are also overlapped at seam 3a, along seam 3b. This
allows the use of manageable lengths of drip gutters 39, that is of
the same length as the sheets of glass 11, that is, for example
eight feet.
[0054] The solar collector panel 1 can similarly be configured for
stand alone operation wherein the roofing structure is replaced by
a lightweight support backing such as corrugated "Chloroplast".
Such standalone solar collector panel may be mounted on a ground
based stationary or dynamically steerable tracking frame that
optimizes the orientation of the solar collector panel 1 as the sun
moves across the sky.
[0055] As will be apparent to those skilled in the art in the light
of the foregoing disclosure, many alterations and modifications are
possible in the practice of this invention without departing from
the spirit or scope thereof. Accordingly, the scope of the
invention is to be construed in accordance with the substance
defined by the following claims.
* * * * *