Hot air cage for solar panel

Abstract

Device for a glazed solar panel which comprises a window (1) made of greenhouse material, which comprises a bottom (3) made of air-impermeable material, which comprises a first opaque and air-impermeable absorber (2), extending between a first face, arranged opposite the window (1) and a second face, arranged opposite the bottom (3), which comprises a first profile (6) comprising a first groove and a second groove, which comprises a first angle iron (7) inserted in the first groove, which comprises a second angle iron (10) inserted in the second groove, in which the absorber (2) is inserted in the first groove in mechanical contact with the first profile (6) and the first angle iron (7), in which the bottom (3) is inserted in the second groove in mechanical contact with the second angle iron (10) and the first profile (6) and in which the first angle iron (7),the second angle iron (10) and the profile (6) are held tight together by a reversible clamping means (8, 9).,

Description

Title of the invention: Hot air cage for solar panel Technical field

[0001] The present application relates to the general field of hot air solar panels.

[0002] The present application relates more particularly to air cages or air ducts for these solar panels. Definitions

[0003] For the purposes of this application, the following definitions apply:

[0004] “Light”: electromagnetic waves for all wavelengths of the electromagnetic spectrum.

[0005] “Sunlight”: electromagnetic waves emitted by the sun

[0006] “Visible light” or “Visible”: electromagnetic waves detectable by a human eye.

[0007] “Infrared light” or “Infrared”: electromagnetic waves with wavelengths longer than visible wavelengths.

[0008] "Greenhouse effect": optical component, material, or surface whose optical properties make it possible to reinforce the heating of the surface of an absorbing or absorbing body, illuminated by the sun through said optical component and generally separated from said component by an air gap. A greenhouse effect optical component may in particular be a window made of mineral glass such as window glass, or any material transparent to the visible and reflective on the surface for the infrared, in this case, the reinforced heating is obtained by infrared radiation between the window and a surface of an absorber, for example via an air gap. A greenhouse effect optical component may in particular be a window made of synthetic glass, such as acrylic glass or Plexiglas® or PMMA or polymethyl methacrylate acrylic, or any material transparent to the visible and absorbent on the surface for the infrared.In this case, enhanced heating is achieved by thermal conduction between the window and an absorber surface, for example via an air gap.

[0009] “Absorber-reflector”: body absorbing light on one part of its surface and reflecting light on another part of its surface.

[0010] “Single-sided absorber”: plate-type absorber-reflector extending between two faces, the absorbing part of which is one of the faces, the other face being reflective.

[0011] “Double-sided absorber”: plate-type absorber extending between two absorbing faces.

[0012] “Air cage”: means in a greenhouse solar panel immersed in the air and comprising an opaque absorber disposed between a transparent window exposed to the sun and a bottom not exposed to the sun, the air space between the absorber and the bottom is generally limited in thickness by the parts of the edges of the panel supporting the absorber and the bottom.

[0013] “Reversible clamping means”: means a clamping means, allowing the loosening, typically without destruction or significant modification of the state of the contact surface of the clamped parts, as opposed to an adhesive which will typically be an irreversible clamping means. An example of a mechanical reversible clamping means is a screw-nut or bolt system. An example of a magnetic reversible clamping means is a magnet-magnet or iron plate magnet system. It is expressly understood within the meaning of this application that the words "reversible clamping means" apply to any type of clamping suitable for the installation and maintenance of a hot air cage in a glazed solar panel, in particular as a functional replacement for an adhesive. Summary of the invention

[0014] In the field of hot air solar panels, the prior art knows glazed solar panels composed of a window, a double-sided absorber and a single-sided reflector, in which the absorber is arranged between the window and the reflector.

[0015] The window of these glass panels is a plate of glass, or any material transparent to visible light and reflective to infrared light.

[0016] The double-sided absorber is in particular a plate of slate or any light-absorbing material extending between two light-absorbing faces, a first face facing the window and a second face facing the reflector.

[0017] The single-sided reflector is a plate of polyurethane insulating foam or any material which is insulating for heat and weakly reflective for light. The surface of the reflector opposite the second face of the absorber is covered with an aluminized film or a film of any metallic material which is reflective for light and conductive for heat.

[0018] The glass panels contain a first blade of still air between the window and the first face of the absorber and a second blade of air set in motion by a fan, between the second face of the absorber and the film.

[0019] The first air blade is contained in a closed cavity or greenhouse and the second air blade is contained in an open cavity or air cage, forming a conduit of a fluid circuit for the air delivered by means of the fan.

[0020] When the window transparent to the visible is exposed to solar radiation, it transmits the visible part of this radiation to the first face of the absorber which absorbs it on its first face by transforming it into heat, heats up internally and re-emits infrared radiation characteristic of its internal temperature, by its first face and its second face.

[0021] The infrared emission via the first face is reflected towards this face by the infrared reflecting window and contributes to additionally heating this face of the absorber in the sun, which is known as the “greenhouse effect” phenomenon. The transparent window is from this point of view an optical component with a greenhouse effect in glass panel type optical systems.

[0022] The infrared emission via the second face is reflected towards this face by the light-reflecting film and contributes to additionally heating this face of the absorber, limiting radiation losses.

[0023] In addition, the insulating foam of the reflector makes it possible to prevent thermal losses by conduction via the second air gap and the aluminized film.

[0024] In order to facilitate the transport, handling and durable installation of the glass panels, the window, the double-sided absorber and the reflector are fixed in mechanical contact with a rigid aluminum frame.

[0025] To minimize heat loss through the frame, the fixing is carried out using silicone glue or any thermally insulating glue.

[0026] However, in the prior art, this fixing makes it almost impossible to dismantle the glass panel, to repair it, change certain elements or recycle it.

[0027] Furthermore, the presence of glue in an environment heated to the maximum by the sun, such as a glazed solar panel, induces significant risks of release of harmful compounds from the glue and degradation of the glue over time, harming the thermal insulation performance of the glazed solar panel.

[0028] However, the installation and maintenance of a window, a double-sided absorber and a reflector at a distance by shims, in an airtight manner and without thermal loss is a difficult problem without glue.

[0029] In this context, the present application relates to a device for a glazed solar panel which comprises a window made of greenhouse material, which comprises a bottom made of air-impermeable material, which comprises a first opaque and air-impermeable absorber, extending between a first face, arranged opposite the window and a second face, arranged opposite the bottom, which comprises a first profile comprising a first groove and a second groove, which comprises a first angle iron inserted into the first groove, which comprises a second angle iron inserted into the second groove, in which the absorber is inserted into the first groove in mechanical contact with the first profile and the first angle iron, in which the bottom is inserted into the second groove in mechanical contact with the second angle iron and the first profile and in which the first angle iron,the second angle iron and the profile are held together by a reversible clamping means.

[0030] In variants:

[0031] - which the bottom surface is reflective for light

[0032] - the surface of the bottom is absorbent for light

[0033] - the bottom surface is reflective for infrared light

[0034] - the bottom surface is absorbent for infrared light

[0035] - the bottom is made of aluminum.

[0036] - the bottom is a second absorber.

[0037] - the bottom is made of acrylic glass.

[0038] - the reversible clamping means comprises a screw-nut system. List of figures

[0039] [Fig. 1] shows an embodiment of the present application which comprises a planar double-sided absorber disposed between a glass window and a reflective aluminum bottom, the absorber is slid into a first groove of a plastic profile and the bottom is slid into a second groove of the plastic profile, a first angle wedges the absorber against a post of the first groove of the profile, a second angle wedges the bottom against a post of the second groove of the profile, a screw passes through the profile to the gap between the absorber and the bottom, passes through the second angle, passes through the first angle and a nut is screwed onto the screw to tighten the profile and the angles together and immobilize the absorber and the bottom in the grooves, following tightening or release them by loosening. Detailed implementation methods

[0040] A first embodiment with reference to [Fig.l] for the numbers in parentheses, uses an absorber (2) or first absorber, which is a double-sided absorber which is a plate of opaque and airtight material or a plate treated on both sides with a coating absorbing for visible light and reflecting for infrared. A black paint may also be used to produce any absorbent face of one of the embodiments of the present application.

[0041] It should be noted that this mode could use, without any disadvantage other than slightly lower performance, a single-sided absorber, which is a metal plate treated on only one of its faces, with a coating absorbing visible light and reflecting infrared, the other face being reflective, for example untreated, therefore slightly more economical.

[0042] It should be noted that the thermal conduction of the absorber can be variable without departing from the general teaching of the present application.

[0043] In this mode, a background (3) opposite the absorber is used. This background is an aluminum plate which conducts heat and reflects in the visible and infrared ranges.

[0044] It should be noted that this mode could use with different performances, an airtight plate having any optical property of reflection or absorption for its faces or its volume.

[0045] It should be noted that the thermal conduction of the bottom can be variable without departing from the general teaching of the present application.

[0046] The space between the absorber and the bottom will be called in all the modes of the present application "air cage" and to obtain a true enclosed space impermeable to air, by limiting its thermal losses, the edges of this space will be provided with air-impermeable elements, possibly pierced with holes and connected to a ventilation system to be able to transport the air heated in this space by the absorber exposed to the sun, up to, for example, the interior of a dwelling in order to achieve energy savings in terms of heating this dwelling.

[0047] As in all the embodiments of the present application, a window (1), made of mineral glass, is arranged opposite the absorbent face of the absorber (2). The absorber is arranged, as in all the embodiments of the present application, between the window and the reflector. The glass of the window is chosen to transmit the visible and reflect the infrared to the extent necessary to obtain a greenhouse effect between the window and the absorbent face of the absorber opposite this window. An insulating foam (4) can also be added to the bottom, in particular if the thermal conductivity of the bottom (3) is too high to allow thermal insulation and limit heat losses via the bottom (3). In addition, a metal frame (5) is added to hold together the air cage according to the present application (2, 3, 6, 7, 8, 9 and 10), the window (1) and the insulating foam (4) if necessary.

[0048] The air cage comprises in this first embodiment as in all embodiments according to the present application: the absorber (2), the bottom (3), a profile (6), a first angle iron (7), a second angle iron (10), a screw (9) passing through the profile (6), the first angle iron (7) and the second angle iron (10) and onto which a nut (8) is screwed to tighten the elements that the screw passes through. As an equivalent to this screw-nut or bolt system, a mechanical means for reversibly tightening the elements forming the air cage and therefore allowing their loosening can be used.

[0049] The absorber and the bottom are held in place relative to each other by a wedge (6, 7, 8, 9, 10) into which they are inserted.

[0050] The wedge comprises the profile (6) comprising a hole framed by two grooves each extending along the length of the profile.

[0051] In a first groove, the absorber will be inserted and clamped against the first groove by the first angle iron (7) plunging into the first groove.

[0052] In a second groove, the bottom will be inserted and clamped against the second groove by the second angle iron (10) plunging into the second groove.

[0053] Furthermore, the screw (9) is inserted into the hole of the profile (6) towards the space between the absorber (2) and the bottom (3), through a hole of the second angle iron and a hole of the first angle iron and the nut (8) is screwed onto the screw (9).

[0054] In this way, tightening the screw (9) causes the nut (8), the first angle iron (7) to tighten on the second angle iron (10) and the second angle iron (10) to tighten on the profile (6).

[0055] To mount the glazed solar panel, an absorber is inserted between the first angle iron and the first groove, then a base is inserted between the second angle iron and the second groove, and the wedge is tightened by turning the screw to tighten the nut.

[0056] The simultaneous result of tightening the first angle iron on the absorber and the absorber on the first groove is then obtained, as well as tightening the second angle iron on the bottom and the bottom on the second groove. To release the absorber and the bottom, the bolt formed by the screw and the nut will be loosened by turning the screw in the opposite direction to the direction used for tightening and keeping the nut fixed, in a manner known from the prior art.

[0057] The profile covering one of the sides of the absorber and the bottom, for example rectangular, it is sufficient to repeat the operation of tightening profiles of the same type on the three remaining sides of the absorber and the bottom to obtain an air cage limited by the profiles, the absorber and the bottom.

[0058] This air cage may be provided with holes to allow air extraction between the absorber and the bottom, for example by two parallel solid profiles and two parallel perforated profiles, together surrounding the edges or the perimeter of the absorber and the bottom.

[0059] Advantageously, the profile is made of heat-insulating material, to limit heat losses through the edges of the air cage, materialized by the profiles.

[0060] As in all embodiments of the invention: - the two angles can be parts of the same piece, which advantageously allows only one hole to be drilled to tighten the two angles on the profile. - the hole in angles forming part of the same part can be threaded and not through to save the nut. - the angles can be deformed to adapt the tightening to several thicknesses of absorber or base. - the angles can be asymmetrical in relation to the screw axis to allow the tightening of absorbers and bottoms of unequal thicknesses - any reversible tightening means equivalent to a screw-nut or bolt system can be used.

[0061] It is noted that if the profile is advantageously made of heat-insulating material, the angles may or may not be heat-insulating, while the screw is insulating preference for heat to avoid a thermal bridge if it is in contact with the inside and outside of the air cage.

[0062] A person skilled in the art will easily determine the thermal conductions of each element of the reversible clamping means by seeking to minimize the thermal bridges caused by the reversible clamping means between the interior of the air cage and the exterior of the glazed panel.

[0063] To obtain a complete hot air solar panel, in a known manner, from the secured air cage, the air cage can be inserted into an aluminum frame (5) and the glass window (1) added to it opposite the absorber (2) and, as indicated above, the insulating foam (4) if the thermal conductivity of the bottom (3) is too high and requires the presence of this insulating foam (4) to limit thermal losses via the bottom (3).

[0064] The air cage obtained above is removable once extracted from the aluminum metal frame by simply unscrewing the screw to loosen the nut tightening its elements, from outside the air cage or by loosening the selected reversible tightening means.

[0065] As in all embodiments of the invention, the material of the bottom may or may not be heat conductive; in the case where it is heat conductive, a heat insulating foam may be placed between the metal frame and the bottom to limit heat losses.

[0066] In this first mode, the bottom being made of aluminum, it is heat conductive and a thermally insulating foam will be used.

[0067] It should be noted that the skilled person would have no reason to use a highly reflective aluminum bottom with a single-sided absorber for this mode. Indeed, the reflective face of the absorber being opposite the reflective face of the bottom, no heating effect in the air cage would be easily anticipated, the infrared light emitted by the absorber undergoing only multiple reflections between these faces, without being able to clearly predict the effect of this configuration, this configuration is nevertheless only a few degrees inferior to a version with a double-sided absorber, unexpectedly, while being slightly less expensive than a double-sided absorber.

[0068] The only technical characteristic of the bottom which is necessary for all the modes of the invention is air impermeability to allow air to be conducted into a fluid circuit supplied by the fan, which leaves a great deal of latitude in the choice of the material making up the bottom.

[0069] This mode for the bottom is the preferred mode for the invention because it allows the use of a metal and thus guarantees stability and durability at the operating temperatures of the hot air solar panel.

[0070] In a second embodiment, the bottom is opaque and has an absorbent surface for infrared or visible light, this is the case for example if the bottom is advantageously a second absorber, such as a single-sided absorber, or a second double-sided absorber of the same type as the first absorber already described, an absorbent face of this second absorber being, for example, opposite the first absorber described above.

[0071] In this second mode where the surface of the bottom is absorbent for visible and infrared light, the infrared light re-emitted by the first absorber is absorbed by the second absorber which heats up and can contribute to heating the air ventilated between the two absorbers. Insulation by thermal foam will also be advantageous in this case if the second absorber is conductive for heat.

[0072] In a third embodiment, the bottom is a mineral glass which reflects infrared and which is transparent to the visible or any material having these characteristics. Since no visible light is re-emitted by the absorber towards the bottom, this mode is equivalent to the first mode, since the infrared emitted by the absorber is reflected by the glass towards said absorber. Advantageously, however, since the mineral glass is substantially two hundred times less conductive to heat than a metal as in the first two modes, it makes it possible to avoid the use of thermally insulating foam or to use a much lesser thickness thereof.

[0073] In a fourth embodiment, the bottom is made of synthetic glass such as acrylic glass. This material is transparent to the visible and absorbent for infrared, any material having these characteristics can be used for this mode. This mode is equivalent to the second mode because the infrared emitted by the absorber is absorbed by the synthetic glass and is used to heat the air ventilated between the absorber and the acrylic glass. Advantageously, however, since acrylic glass is still substantially ten times less conductive to heat than a mineral glass considered in the third mode, it makes it possible to further avoid the use of thermally insulating foam or to use a lesser thickness than in the third mode.

[0074] In all the embodiments of the present application, the air cage obtained via an absorber and a bottom is, in any event, removable, thanks to the profile, via its grooves, its angles and its means of reversible assembly of these components within the heated glass panel produced according to the present application.

[0075] The invention is capable of industrial or useful application in the field of glazed hot air solar panels.

[0076] For the insulating foam of all the embodiments of the invention where it is necessary, polyethylene terephthalate foam with a thickness typically equal to 17 mm may be used.

[0077] For the material of the profile of all the modes of the invention, it will be possible to select PA6 plastic material. This material can also be used for corners.

[0078] For the connection between the nut and the screw, in all the embodiments of the invention which use them, it will be advantageous to add a spring threaded onto the screw to facilitate the tightening and loosening of the nut.

[0079] For other embodiments in accordance with the teaching of the present application, it is also possible to use:

[0080] - a base made of cork or any heat-insulating material.

[0081] - a double-sided heat absorber, such as an aluminum plate or metallic, extending between two faces and blackened on both faces or a plate coated with an anti-reflective treatment for the infrared spectrum on one of these faces and blackened on the other face, or a single-sided absorber whose reflective face is blackened to make it absorbent.

[0082] - a double-sided heat absorber, made using a plastic material opaque or any bulk absorbing material.

[0083] The teaching of the present application thus extends to any absorber opaque to the sun and impermeable to air, opposite an air-impermeable base, delimiting between the absorber and the base, a space forming an air cage.

[0084] In a preferred embodiment of the invention, the profile and the angles according to the present application will again preferably be made of heat-insulating material. This makes it possible to limit heat losses through the edges of the space between the absorber and the bottom. The profile and angles will preferably extend around the entire perimeter of this space, again called an "air cage", for the same reasons. This will thus delimit a volume of air heated by the sun via the absorber when this absorber is illuminated by sunlight, for an absorber which absorbs at least part of the spectrum of this sunlight, i.e. an opaque absorber for sunlight.

[0085] The present application thus makes it possible to produce in all its modes, thanks to the profile, the angles and a reversible mechanical means of clamping these elements, a removable heated glass panel. This facilitates transport and recycling. But the absence of glue also allows use in the sun, at a temperature as high as that permitted for the angles, potentially well above the maximum temperature for safe use of the glues used for the heated glass solar panels of the prior art. Indeed, these glues are notably limited in temperature range by the non-emission of substances harmful to a human being.The invention according to the present application makes it possible to obtain the above advantages with simple means of use and in particular easily screwed and unscrewed from the outside of the air cage according to the invention, through the profile and the angles, by choosing mechanical means for tightening these parts in the means available in the prior art, in particular screw-nut, especially for a nut in . contact with the air of the air cage and a screw in contact with the air outside this air cage, i.e. a reversible tightening means or tightening / tightening accessible from outside the air cage.

[0086] Again, a preferred embodiment for the invention will utilize a double-sided absorber and an aluminum reflective bottom, as there is an increase in the temperature of the air present in the air cage between the absorber and the bottom, which reaches one to two degrees Celsius (1 to 2°C) for this configuration, compared to a configuration with the same reflective bottom facing a reflective face of a single-sided absorber.

[0087] In the sense of the theory of equivalents, any opaque absorber, i.e. made of a material opaque to light, can be used as a double-sided absorber.

[0088] Without departing from the teaching of the present application, it is also possible to use an absorber that is partially reflective on one of its faces or on both, or partially absorbent on one of its faces or on both.

[0089] It is also possible, without departing from the teaching of the present application, to also use a reflector which is partially reflective on one of its faces or on both, or partially absorbent on one of its faces or on both.

[0090] In all embodiments of the present application, the tightening of the reversible tightening means will be dimensioned, for example in terms of its dimensions, its mechanical clearances and / or its deformations, to maintain without damaging them, the absorber in the first groove of the profile and the reflector in the second groove of the profile, either simultaneously or sequentially, to the extent necessary to maintain in place, in normal use, the desired air cage.

[0091] In all embodiments of the present application, the reversible clamping means is accessible from outside the air cage, to the extent necessary to allow disassembly of this air cage.

[0092] The present application makes it possible to obtain, using simple means, a removable glazed heating solar panel.

[0093] It will be expressly understood from the present application in all its embodiments that the reversible clamping of the elements useful for obtaining a removable air cage can: either pass through a frame, in which the removable air cage is included and bear on a profile against which an absorber and a bottom are held tight, or remain outside the frame by bearing on this frame, as soon as the reversible clamping effect of the absorber and the bottom in grooves of the profile via angles inserted in the grooves is obtained.

[0094] Likewise, it will be expressly understood from the present application in all its embodiments, that a reversible clamping means means juxtaposed or superimposed angles, with a clamping system allowing them to be clamped on the profile, being understood that the shape of these angles will be designed to minimize the size of these angles.

[0095] It will be understood for the purposes of the present application that an “angle”, known from the prior art as a mechanical part admitting in section perpendicular to its length two branches at right angles, can also have any angle between its branches for the purposes of obtaining the effects of the present application.

[0096] In all embodiments of the present application, it will be understood that an angle iron and a profile comprising a groove are adapted to each other to realize any mode of the invention, if tightening the angle iron against the profile with one of the branches of the angle iron inserted in the groove, deforms the angle iron. The person skilled in the art will then easily determine, as a function of the calculated or measured deformation, a width of the groove allowing, when the angle iron is inserted in the groove without deformation, also to insert into the groove an element of given thickness (absorber, bottom, ...) and allowing the element to be wedged in the groove by the deformed angle iron.

Claims

Claims

1. Device for a glazed solar panel which comprises a window (1) made of greenhouse material, which comprises a bottom (3) made of air-impermeable material, which comprises a first opaque and air-impermeable absorber (2), extending between a first face, arranged opposite the window (1) and a second face, arranged opposite the bottom (3), which comprises a first profile (6) comprising a first groove and a second groove, which comprises a first angle iron (7) inserted in the first groove, which comprises a second angle iron (10) inserted in the second groove, in which the absorber (2) is inserted in the first groove in mechanical contact with the first profile (6) and the first angle iron (7), in which the bottom (3) is inserted in the second groove in mechanical contact with the second angle iron (10) and the first profile (6) and in which the first angle iron (7),the second section (10) and the profile (6) are held together by a reversible clamping means (8, 9).

2. A device according to claim 1 wherein the bottom surface is light reflective.

3. A device according to claim 1 wherein the bottom surface is light absorbent.

4. A device according to claim 1 wherein the bottom surface is reflective for infrared light.

5. A device according to claim 1 wherein the bottom surface is absorbent for infrared light.

6.

7. Device according to claim 2 in which the bottom is made of aluminum. Device according to claim 3 in which the bottom is a second absorber.

8. Device according to claim 4 in which the bottom is made of mineral glass.

9. Device according to claim 5 in which the bottom is made of acrylic glass.

10. Device according to any one of claims 1 to 9 in which the reversible clamping means comprises a screw-nut system.

Images