FR2476813A1 - Self supporting solar heating panels - are made of absorbent material sandwiched between insulating panel and glazing and can be bolted together to form watertight roof - Google Patents

Abstract

The upper face of the panel is glazed (2) and an absorbent panel (6) is fixed between the glazing and insulating base. The space (4) between the glass (2) and the upper black surface of the absorber contains stagnant air whilst the space below (8) forms an air duct through which the cooling air flows. When several panels are connected in parallel, the air ducts are interconnected by an inlet and exit manifold. The assembly is rendered watertight by the use of jointing strips (22) between the lateral edges of the absorbant panel and the elements (20,40) forming flanges along the edges. The absorbant panel is coated on its upper surface with a covering which retains its light absorbing properties even if a small amount of water is admitted.

Description

Self-supporting panel solar collector forming a waterproof cover for a building
The present invention relates to a self-supporting panel solar collector forming a waterproof cover.

 Solar energy collectors are known which are intended to heat a heat transfer fluid by solar radiation which then makes it possible, immediately or deferredly, to heat residential premises or the water used in the sanitary appliances of such premises.

 The sensor is generally in the form of a panel, and the heat transfer fluid used is water.

 It is also known, in particular from French patent application No. 2 404 816, to manufacture such sensors from thermally insulating cladding which is industrially produced elsewhere to constitute water-tight covers on inclined roofs at low cost. or the walls of various premises. Such cladding generally consists of a layer of rigid insulating foam formed between two sheets and having longitudinal ribs intended to be arranged in the direction of greatest slope.

These ribs stiffen the cladding so as to make it self-supporting, that is to say that it can be fixed, without risk of deformation on beams arranged at normal spacing, for example 3 or 4 m, perpendicular to the ribs.

 In addition to their low cost price, such cladding has the advantage of making it possible to easily form roofs that are waterproof against rainwater, this thanks to a suitable covering of the folded sheets placed on the longitudinal ribs at the junction between two adjoining panels. .

 To make a solar collector from such cladding it is necessary to have, above the surface absorbing the radiation (blackened sheet for example), a glazed surface which can bear on the ribs of the cladding, and which is necessary for isolate the sensor thermally from the outside atmosphere. It is also necessary to allow the circulation of the heat transfer fluid in thermal contact with an absorbent surface area as large as possible. For this it is necessary to constitute almost the entire area of the cladding so as to allow this circulation according to a suitable path, which is sinuous if the heat transfer fluid is water.

 The known sensors do not make it possible to obtain both these results and a waterproof cover under satisfactory cost conditions.

 The object of the present invention is to produce a solar collector with a self-supporting panel forming a waterproof cover for a building making it possible to obtain, in a simple manner, sufficient sealing of the cover formed by the panel.

 It has a self-supporting panel solar collector forming a watertight cover for a building, this collector having the form of panels with an upper face intended to be exposed to the sun, and longitudinal ribs forming upward projections and intended to be arranged according to lines of greatest slope, this sensor comprising, between the ribs, from the upper face - a window pane allowing the solar radiation to pass, - a layer of stagnant air constituting a thermal insulator, - an absorbent wall absorbing the solar radiation on its upper face and heating under the action of this radiation, - a layer of heat transfer fluid circulating in contact with the lower face of this absorbent wall to be heated by this wall, - and a thermally insulating panel comprising longitudinal ribs protruding upwards and giving the sensor sufficient rigidity to make it self-supporting, - the glass and the absorbent wall resting on at least some of these ribs, characterized in that clamping means compress elastic seals between the lateral edges of the absorbent wall and elements of said ribs so as to seal the covering surface formed by this sheet and these ribs, the absorbent wall being coated on its upper face with a coating absorbing light energy and capable of retaining its absorbent properties in the presence of water infiltration between the side edges of said window and said ribs, - said layer of circulating heat transfer fluid being constituted by a set of air channels circulating longitudinally, each channel being included, laterally between two said ribs, and, vertically between said insulating panel and said insulating wall.

 Using the attached schematic figures, we will describe below without limitation, how the invention can be implemented. It should be understood that the elements described and shown can, without departing from the scope of the invention, be replaced by other elements ensuring the same technical functions. When the same element is represented in several figures, it is designated therein by the same reference sign.

 FIG. 1 represents an exploded perspective view of part of a sensor according to the invention.

 FIG. 2 represents a cross-sectional view of the sensor of FIG. 1 and of a beam supporting this sensor.

 FIG. 3 represents a bottom view of the same sensor on a smaller scale.

 FIG. 4 represents a side view of the sensor of FIG. 3.

 FIG. 5 represents a view in longitudinal section of the upper end of the sensor of FIG. 1.

 The sensor described consists of identical flat panels 70, 71 and 72 whose length can reach, for example, up to 10 m and whose width can be of the order of 1 m. These panels are stiffened by longitudinal ribs on their lateral edges.

Although this is not shown, several longitudinal ribs can be formed between the lateral edges to improve rigidity or facilitate heat exchange. The juxtaposition of such panels can constitute the inclined cover of a living space, the length of the panels being arranged in the direction of greatest slope, or even vertically.

 In the interval between the ribs the sensor comprises the following elements, starting from its upper face exposed to the sun - a window 2, thick for example of 4 mm, letting through the solar radiation and insulating a layer of stagnant air 4 which is for example 3 cm thick and constitutes a thermal insulator.

- an absorbent wall (6) made of a steel sheet, for example 0.5 mm thick and the upper face of which has been blackened so as to best absorb solar radiation while re-emitting only little radiation thermal likely to cross the window 2.

 The black coating is chosen so as to retain its absorbent properties in the presence of water infiltration which would reach it from the edges of the glass 2. The underside of this absorbent wall is licked by a layer (8) of air circulating longitudinally and constituting the heat transfer fluid. This layer is, for example - 1.5 cm thick, - an insulating panel consisting essentially of a rigid foam layer 10, for example 5 cm thick, which is self-supporting with the help of a bottom wall 12 consisting of a thick sheet for example 0.5 mm which, although not shown, can be ribbed with ribs of low height (less than a centimeter for example). This layer of foam can be manufactured in the factory with the help sheets 12 and 6, and separating elements temporarily inserted between sheet 6 and the foam-forming material.

Such manufacture can be done at a cost all the lower since it is almost identical to that of insulating cladding currently manufactured in large series and consisting of a layer of foam between two ribbed sheets.

 Longitudinal ribs are arranged on the lateral edges which allow the mechanical and sealing connection of the adjoining panels such as 70 and 71. These ribs take a different shape depending on whether they are on the right or left edge of the panel, so as to what the right rib of the first panel 70 cooperates with.

the left rib of a second panel 71 located to the right of the first.

 The right rib first comprises, going from left to right, a flat 20, for example 5 cm wide, and bringing the thickness of the foam layer for example to 8 cm. On this flat surface are supported a raised straight edge strip of the sheet 6, and the right edge of the window 2. This edge strip being formed by two longitudinal folds 90 and 92. The assembly of the two edges is surrounded by a insulating elastic seal 22, for example 0.5 cm thick and extending, under the lower face of the sheet 6, over the entire width of the flat 20, and, on the upper face of this sheet and on the glass 2 on a width of 8 cm.

 The thickness of this seal is increased on this window, for example tripled, so as to avoid excessive short-circuit thermal conduction via this window between the atmosphere and the sheet 6.

 The rib then comprises a projection 24 coated with an upper sheet 26 extending as far as the flat 20, and comprising, from its left edge situated over the width of the flat 20, a vertical return 27 ensuring anchoring in the foam insulating 10 under the flat. This sheet constitutes, on the ribs, an upper ar atuPi of a beam, the friend of which is constituted by the foam 10 and the lower frame of which is constituted by the sheet 12. The sheet 26 has moreover a significant inherent rigidity. The return 27 is isolated from the sheet 12 by 5 cm of foam, and from the air layer.

circulating 8 per 2 years of foam, corresponding for example to half the width of the flat 20, so as not to constitute an annoying thermal bridge. The projection 24 and the sheet 26 extend upwards above the window 2. The sheet 26, the gasket 22, the sheet 6 and by means of @@ flat 20 by rivets 28 which com @@@ @@ make a good seal between the sheet 6 and the rib.

 The rib finally comprises a flat 30 of very small thickness and covered by a return of the sheet 12 to allow during mounting by means of screws not shown, an at least temporary fixing of the panel on a beam 32, which is shown ' eo-e arranged longitudinally to facilitate understanding of the drawing, but is advantageously arranged transversely to allow taking advantage of the rigidity provided by the longitudinal ribs.

 The left rib has projecting on its upper face, a flat 40 identical to the flat 20 and on which the sheet 6 and the glass 2 are fixed in the same way, as well as a sheet 44 of shape similar to that of the sheet 26, and comprising from its right edge, a vertical return 45 ensuring an anchoring in the insulating foam 10. On the lower face the rib forms a recess 42 coated by the sheet 12 and making it possible to bear on the flat 30 of the panel on the left 70. The shape of the sheet 44 allows it to cover the sheet 26 by fitting the projection 24 of the left panel.

 These two sheets are fixed to the beam 32 by bolts 46 which pass through the entire height of the projection 26, an annular rubber seal being compressed by a washer to ensure watertightness at the level of the hole drilled for passage. of each of these bolts.

 The layer of stagnant air is closed at the lower and upper ends of each panel, by a plug of insulating foam such as 52 (Figure 5). The layer of circulating air 8 is closed at the upper end by a similar plug 54. It can also enter it at the lower end if an inlet distributor 56 is provided, as shown in FIGS. 3 and 4. it is however often simpler not to provide such a distributor and to supply this layer with atmospheric air.

 The air heats up in the sensor by circulating in the channel which is formed by the layer 8 between the ribs it leaves there by openings such as 58 drilled in the layer of foam 10 and the sheet 12, and opening directly into a outlet collector 60.

This collector consists of a chute whose walls are thick and made of thermally insulating foam 60 coated with a sheet metal 62. These walls are 3 in number forming in section three sides of a rectangle open upwards over the entire length of the collector. This length is shown perpendicular to that of panels such as 70, 71 and 72, but the angle between these lengths could be different from 900, for example 450 or 600.

 The general shape of the section is that of a U with an inner branch 64, a base 66 and an outer branch 68, of the same constitution and of the same thickness, the ends of the branches coming to bear against the panel. The insulating foam contained in these walls can be chosen to be flexible enough to ensure a suitable airtightness when the sheets such as 62 are fixed to the panel, this despite the ribs or the unevenness which the surface of the panel presents. We may prefer a rigid foam supplemented, at the ends of the branches of the U, by a strip of glued flexible foam.

 The outer branch 68 rises higher than the inner branch 64 so as to be applied against the upper edge of the panel and it is folded over the panel to be fixed, on a rib by a bolt such as 46 at the top of the sign. This arrangement facilitates the fixing of the collector and improves sealing, a joint being provided between the part of the sheet metal 62 located above the panel and the upper surface of the latter, between the ribs.

 FIG. 5 is a section passing through the axis of a single outlet opening 74 of the collector 60.

 The openings 58 can be circular or rectangular.

Their dimensions are chosen so as to balance the flow rates in said air channels. it is generally advantageous to carry out this balancing using an adjustable diaphragm.

 A rigid and suitably folded plastic sheet could of course be used in place of the various sheets mentioned above, in particular sheet 62.

Claims (2)

1 / Solar collector with self-supporting panel forming a watertight cover of a building, this collector having the form of panels with an upper face intended to be exposed to the sun, and longitudinal ribs forming projections (24) upwards and intended to be arranged along lines of greatest slope, this sensor comprising, between the ribs, from the upper face, - a window (2) allowing the solar radiation to pass, - a layer (4) of stagnant air constituting a thermal insulator , - an absorbent wall (6) absorbing solar radiation on its upper face and heating under the action of this radiation, - a layer (8) of heat transfer fluid circulating in contact with the lower face of this absorbent wall to be heated by this wall, - and a thermally insulating panel (10) comprising longitudinal ribs projecting upwards and giving the sensor sufficient rigidity to make it self-supporting, - the glass and the absorbent wall resting on at least some of these ribs, characterized in that clamping means 28 compress elastic seals (22) between the lateral edges of the absorbent wall (6) and elements (20,40) said ribs so as to seal the covering surface formed by this sheet and these ribs, the absorbent wall (6) being coated on its upper face with a coating absorbing light energy and capable of retaining its properties absorbent in the presence of water infiltration between the lateral edges of said window and said ribs, - said layer (8) of circulating heat transfer fluid being constituted by a set of air channels circulating longitudinally, each channel being included, laterally between two said ribs, and, vertically between said insulating panel and said insulating wall. 2 / sensor according to claim 1, characterized in that said absorbent wall has, when approaching each of its lateral edges, a first fold (90) causing the wall to rise upwards and a second fold (92) in in the opposite direction bringing it parallel to the whole of the wall to form a raised flat edge strip coming to bear on a flat (20, 40) of the rib, said seal (22) surrounding this edge strip bypassing the edge of the absorbent wall.