FR2476811A1 - Self supporting solar heating panel - has absorbent layer between glazing and base with air ducts between its lower surface and base - Google Patents

Abstract

The upper face of the panel is glazed (2) and an absorbant panel is fixed between the glazing and insulating base. The space between the glass and the upper block surface of the absorber contains stagnant air whilst the space below 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) and cover joints (50) which fit over the full length of each longitudinal joint. A thermally insulated exit pipe (60) is formed on the undersurface of the panel and crosses over longitudinal ribs formed in the panel. The panel also has a series of apertures (58) formed in it to communicate the air ducts with the exit pipe.

Description

Self-supporting panel solar collector with heated fluid collector
The present invention relates to a self-supporting panel solar collector with a heated fluid collector.

 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. It is also necessary to provide connections in parallel and / or in series to introduce the heat transfer fluid at the inlet and collect it at the outlet.

 Finally, a sufficient seal must be provided so that rainwater does not come to deteriorate the absorbent surface.

 Known sensors do not allow these results to be obtained under satisfactory cost conditions.

 The object of the present invention is to produce a solar collector with a self-supporting panel with a collector of the heated fluid, making it possible to lower the cost price of the circuit of the heat-transfer fluid.

 Its subject is a solar collector with a self-supporting panel with a collector of the heated fluid, 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 allowing the solar radiation to pass through, - an absorbent wall absorbing the solar radiation on its upper face and heating up under the action of this radiation, - a layer of heat transfer fluid circulating in contact with this absorbent wall to be heated by this wall, - and a thermally insulating panel comprising longitudinal ribs projecting upward and giving the sensor sufficient rigidity to make it self-supporting , - the window resting on at least some of these ribs, - means being provided for entry and exit of the heat transfer fluid of said layer of circulating fluid, these means comprising at least one outlet manifold, characterized in that said layer of circulating heat transfer fluid is constituted by a set of air channels circulating longitudinally, each channel being included, laterally, between two said ribs, - said outlet manifold being constituted by a thermally insulating wall conduit formed under the underside of said insulating panel by crossing said ribs at the top of said air channels, - this insulating panel being pierced with openings connecting communicating the top of each of said air channels with said outlet manifold.

 The fact that the heat transfer fluid is air not only makes it possible to simplify the circuit of this fluid on the surface of the sensor, but also, in certain cases, to very simply carry out the inlet connection, by simple opening of the channels of air on the atmosphere at their lower end. As for the outlet collector, its manufacturing and installation price is also greatly lowered.

 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 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.

 Figure 3 shows 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, with an outlet manifold according to a first variant of that shown in FIGS. 3 e and 4.

 FIG. 6 represents a view in longitudinal section of the upper end of the sensor of FIG. 1, with an outlet manifold according to a second variant of that shown in FIGS. 3 and 4.

 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 the solar radiation while reemitting only little thermal radiation likely to pass through the window again 2-.

The underside of this absorbent wall is licked by a layer (8) of air flowing longitudinally and constituting the heat transfer fluid.

This layer is for example 1.5 cm thick. The thermal contact between this wall and this layer can be improved by ribs, fins or various reliefs on the underside of this wall.

an insulating panel essentially consisting of a rigid foam layer 10, for example 5 cm thick, which is self-supporting with the help of a bottom wall 12 made of a thick sheet, for example 0.5 mm which, although this is 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 of the sheets 12 and 6, and of separating elements temporarily inserted between the sheet 6 and the material forming the foam.

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 that 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. The raised right edge of the sheet 6 and the right edge of the glass 2 are supported on this flat.

The assembly of these two edges is surrounded by an insulating elastic seal 22, for example 0.5 cm thick and extending, under the underside 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 over 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 located over the width of the flat 20, a vertical return 27 ensuring anchoring in the insulating foam 10 under the flat. This sheet constitutes, on the rib, an upper frame of a beam whose friend is formed by the foam 10 and whose lower frame is formed by the sheet 12. The sheet 26 also has a significant inherent rigidity. The return 27 is isolated from the sheet 12 by 5 cm of foam, and from the circulating air layer 8 by 2 cm of foam, corresponding for example to half the width of the flat 20, so as not to constitute a thermal bridge embarrassing.

The projection 24 and the sheet 26 extend upwards above the window 2. The sheet 26, the seal 22, the sheet 6 and by means of the seal 22, the window 2 are fixed to the flat 20 by rivets 28.

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

 The rib on the left 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 15 ensuring anchoring in the insulating foam 10. On the underside the rib forms a recess 42 coated by the sheet 12 and making it possible to bear on the flat 30 of the left panel 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.

 A seal cover 50 (FIG. 2) is also fixed by the bolt 46 with annular rubber seal and washer so as to cover all of the complementary ribs of the two adjoining panels, the edges of this counter seal coming to bear. on seals such as 22.

 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 circulating air layer 8 is closed at the upper end by a similar plug 54. It can also be at the lower end if an inlet distributor 56 is provided, as shown in FIGS. 3 and 4. However, it is 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 through openings such as 58 drilled in the foam layer 10 and the sheet 12, and opening directly into an outlet manifold 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 panel . This arrangement facilitates the fixing of the collector and improves the tightness, 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 constituted by a simple plate 80 (FIG. 6) adjustable in position and fixed under the insulating panel, for example by screws passing through oblong holes drilled in this plate. . To allow this adjustment, the bottom of the collector, that is to say the base of the U, has an access hatch 82, the plane of FIG. 6 passing through such a hatch.

 The variant embodiment of the collector shown in FIG. 6 is distinguished by the fact that the collector is formed by simply digging a thick insulating layer 84 placed under the panels such as 70.

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

 Furthermore, it is obvious that the outlet manifold disposed according to the present invention could also be used in the case where there is no layer of stagnant air and where the heated air circulates between the glass and the wall. absorbent which would constitute the upper face of the insulating panel.

Claims (9)

1 / Solar collector with self-supporting panel with collector of the heated fluid, 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 according to lines of greater slope, this sensor comprising, between the ribs, from the upper face - a window (2) allowing the solar radiation to pass through, - an absorbent wall (6) absorbing the solar radiation on its upper face and s 'heating under the action of this radiation, - a layer (8) of heat transfer fluid circulating in contact with this absorbent wall to be heated by this wall, - and a thermally insulating panel (10) comprising longitudinal ribs projecting towards the high and giving the sensor sufficient rigidity to make it self-supporting, - the glass pressing on at least some of these ribs, - means being provided for entry and exit tie of the heat transfer fluid from said layer of circulating fluid, these means comprising at least one outlet manifold, characterized in that said layer (8) of circulating heat transfer fluid is constituted by a set of air channels circulating longitudinally, each channel being understood, laterally between two said ribs, - said outlet manifold being constituted by a conduit (60) with thermally insulating wall formed under the underside of said insulating panel by crossing said ribs at the top of said air channels, - this insulating panel being pierced with connection openings (58) communicating the top of each of said air channels with said outlet manifold. 2 / sensor according to claim 1, characterized in that said conduit constituting the collector has the shape of a trough applied against the underside of said insulating panel the section of this trough having the shape of the letter U, the opening of the U being upwards so that the two edges of this wall come into tight contact with the underside of this insulating panel. 3 / sensor according to claim 2, characterized in that said U has two uneven branches located on either side of said connection openings, an inner branch (64) being located on the side of the center of the sensor, relative to said openings connection (58), and a higher outer leg (68) rising opposite the upper edge of the sensor and being applied sealingly against this edge. 4 / A sensor according to claim 3, characterized in that said collector consists of a thick insulating material enveloped by a folded thin rigid sheet (62), this sheet returning above the sensor from its upper edge. 5 / sensor according to claim 1, characterized in that the duct constituting said manifold is hollowed out in a thick insulating layer (84) disposed under said insulating panel (70). 6 / sensor according to claim 1, characterized in that each of said openings (58) is provided with an adjustable diaphragm (80). 7 / sensor according to claim 6, characterized in that the wall of said manifold comprises hatches (82) for access to said adjustable diaphragms (80). 8 / sensor according to claim 1, characterized in that said air channels are supplied at their lower end by an inlet distributor similar to said outlet manifold. 9 / A sensor according to claim 1, characterized in that said air channels are open to the atmosphere at their lower end.