Solar thermal collector

Abstract

Solar thermal collector. The invention relates to a solar thermal collector (1) in the form of a panel (2) comprising a rear wall (3) and a peripheral wall (4) delimiting an enclosure (5) closed by a transparent front wall (6), within the enclosure (5) extending at least one tube (8) of a heat exchanger (9) through which a heat transfer fluid flows between at least one inlet (13) and at least one outlet (14). The rear wall (3) and the peripheral wall (4) are made of an expanded insulating material, within the enclosure (5) being provided at least one groove (7) of a cross-section fitted to accommodate a tube (8) of the exchanger (9). Figure for the abstract: Fig. 1

Description

Title of the invention: Solar thermal sensor

[0001] The invention relates to a solar thermal collector with circulation of thermal fluid.

[0002] This invention relates to the field of thermal solar panels, of which various embodiments are already known.

[0003] Such thermal solar panels, also called thermal solar collectors or individual solar water heaters, are intended, for the most part, to heat water circulating in a heat exchanger using solar energy.

[0004] In particular, it is known that unglazed flat collectors consist of a network of synthetic tubes, often black in color, extending in the form of a sheet between an inlet collector and an outlet collector. These flat collectors or sheets of tubes are directly exposed to solar rays and do not benefit from any insulation.

[0005] Glazed flat collectors are also known in the form of panels defined by a rear wall surmounted by a peripheral edge in the form of a frame receiving a glazed front wall. This delimits, with the rear wall, a space for housing a tubular exchanger in which water is circulated between an inlet and an outlet, either by thermo siphon, or forced by a circulator. The interior of these panels is black in color so as to absorb as much heat as possible from solar radiation, the glazed front wall trapping this captured heat.

[0006] Tubular collectors are also known, more expensive than the previous ones, which consist of a plurality of vacuum tubes comprising an absorbent coating to optimally capture solar radiation. The resulting thermal energy is absorbed by a thermal fluid which circulates in exchanger tubes extending inside these vacuum tubes. Here again, these tubular collectors take the form of panels surmounted by these vacuum tubes at the rear of which is arranged a reflector panel.

[0007] Apart from unglazed flat plate collectors which have only limited utility due to their low efficiency resulting from the absence of thermal insulation, the other two types of solar thermal collector are of complex design and require compliance with strict installation conditions, in particular due to their weight. This makes them expensive solar thermal collectors and, at the same time, fragile due to their design using materials with very distinct properties and responding differently to the effect of temperature variations.

[0008] Consequently, although technologically very advanced and expensive, they are subject to heavy use over time, affecting their longevity.

[0009] It is within the framework of an inventive approach that we have imagined a solar thermal collector with good performance, simple and light design, therefore with a lower manufacturing cost and easy installation.

[0010] The invention relates to a solar thermal collector in the form of a panel, comprising a rear wall and a peripheral wall delimiting an enclosure closed by a transparent front wall, in the enclosure extending at least one tube of a heat exchanger crossed by a heat transfer fluid between at least one inlet and at least one outlet, characterized in that the rear wall and the peripheral wall are designed in an expanded insulating material, in the enclosure delimited by these walls being provided at least one groove of adjusted section for housing a tube of the exchanger.

[0011] Advantageously, several grooves delimited by separating walls are provided in the enclosure, each of these grooves extending in section adjusted for receiving a tube of the exchanger.

[0012] According to an advantageous embodiment, the rear wall, the peripheral wall and the enclosure are defined by a block, preferably parallelepiped, of an expanded material of polyurethane or other type, in which at least one groove is provided for housing an exchanger tube.

[0013] According to another feature of the invention, the same exchanger tube extends successively in each of the grooves of the enclosure, between the inlet and the outlet that the thermal solar collector comprises.

[0014] Advantageously, an exchanger tube is designed in black color. According to another feature, this tube comprises, over all or part of its length, corrugations each defined by a peripheral protuberance external to the tube and an annular hollow internal to the latter.

[0015] According to yet another feature of the invention, the transparent front wall is defined by a film or a transparent plastic tarpaulin.

[0016] Advantageously, this transparent plastic film or tarpaulin constitutes an envelope of the solar thermal collector according to the invention.

[0017] The advantages arising from the present invention consist in that this thermal solar collector is of particularly simple design. The expanded material of which it is composed is light, which makes it easier to hang on the facade of a building.

[0018] The film forming the transparent front wall of this sensor ensures its sealing by surrounding it.

[0019] As an exchanger tube, a corrugated polyethylene tube can be used, of the ICTA electrical sheath type, which has the advantage of withstanding strong expansions thanks to its corrugations. This characteristic is particularly interesting in that The solar thermal collector according to the invention can be supplied with water without adding an antifreeze additive, even in regions where the risk of frost is high.

[0020] Other aims and advantages of the present invention will appear during the description which follows relating to an exemplary embodiment given for informational and non-limiting purposes.

[0021] Understanding of this description will be facilitated by referring to the figures of the attached drawings in which:

[0022] [Fig-1] [Fig. 1] is a schematic and perspective representation of an exemplary embodiment of a solar thermal collector according to the invention, the transparent front wall not having been illustrated;

[0023] [Fig.2] [Fig.2] is a schematic and cross-sectional representation of the sensor solar thermal of [Fig.l], the transparent front wall having been illustrated;

[0024] [Fig.3] [Fig.3] is a schematic, partial and perspective representation of a dividing wall between two grooves.

[0025] [Fig.4] [Fig.4] is a schematic cross-sectional representation of a groove configured according to the invention and accommodating an exchanger tube, also being illustrated in a schematic manner incident solar radiation perpendicular to the plane of the collector;

[0026] [Fig.5] [Fig.5] is a representation similar to [Fig.4] the radiations solar incident on the sensor forming an angle a relative to the plane of the latter;

[0027] [Fig.6] [Fig.6] is a representation similar to Figures 4 and 5 with solar radiation forming an angle of incidence [3 on the sensor.

[0028] As shown in the attached figures, the present invention relates to a solar thermal collector 1, in the form of a panel 2, with circulation of thermal fluid.

[0029] More particularly, this panel 2 of the solar thermal collector comprises a rear wall 3 and a peripheral wall 4 advantageously designed in insulating material and delimiting an enclosure 5 closed by a front wall 6 which is at least translucent, preferably transparent.

[0030] Said rear walls 3 and peripheral walls 4 are designed, according to a preferred embodiment, in an expanded insulating material, of the polyurethane type.

[0031] In particular, the panel 2 of the solar thermal collector 1 may be made from a block of expanded insulating material, preferably of parallelepiped shape, the rear face and the periphery of which respectively define the rear wall 3 and the peripheral wall 4.

[0032] At the level of the enclosure 5 is provided at least one groove 7 open in the direction of the front wall 6 for housing a tube 8 of a heat exchanger 9.

[0033] Advantageously, at the level of this enclosure 5 several grooves 7 are provided which are substantially parallel to each other, for housing in each of them a tube 8 of exchanger 9, to form a network of tubes 10.

[0034] The grooves 7 communicate at their ends with intercommunication clearances 11, 12 for the parallel connection, preferably in series as illustrated in the figures, of the tubes 8 of the network 10.

[0035] In the case of parallel mounting, these intercommunication clearances 11, 12 contribute to the housing of inlet and outlet collectors of the tubes 8 in the grooves 7. In the case of series mounting, these intercommunication clearances 11, 12 allow the same tube 8 to reach, from a given groove 7, another adjacent one to define a serpentine-shaped exchanger circuit, from at least one inlet 13 and at least one outlet 14 that the panel 2 comprises.

[0036] Advantageously, this inlet 13 and this outlet 14 are arranged in the rear wall 3 and / or in the peripheral wall 4 of this panel 2, in communication with at least one of the intercommunication clearances 11, 12.

[0037] Such a solar thermal collector 1 according to the invention is more particularly intended to be positioned vertically on the facade of a building, an installation which is much simpler to achieve compared to a roof installation.

[0038] Also, this solar thermal collector 1, in accordance with the invention, is preferably in the shape of a rectangular parallelepiped and comprises an upper longitudinal border wall 15, a lower longitudinal border wall 16 and vertical lateral border walls 17, 18, together forming the peripheral wall 4, as well as a rear wall 3, defined as vertical.

[0039] As for the grooves 7, they extend in the enclosure 5, preferably horizontally, therefore longitudinally and parallel between the upper longitudinal border wall 15 and the lower longitudinal border wall 16. The intercommunication clearances 11, 12 are located, in this enclosure 5 at the ends of the grooves 7, extending parallel to the vertical lateral border walls 17, 18.

[0040] A groove 7 is delimited by a bottom wall 19 from which extends an upper wall 20 and a lower wall 21. These preferably respect, according to the invention, a spacing 22 of width adjusted tightly to the section of a tube 8, for a slight housing by wedging of these tubes 8 in the grooves 7.

[0041] According to another feature of the invention, the upper wall 20 of a groove 7 comprises, starting from the bottom wall 19, a first wall portion 23 perpendicular to this bottom wall 19 and extended by at least one second wall portion 24 widening out to form an angle α of between 35 and 60° relative to the first wall portion 23.

[0042] The particularity of this configuration consists in that solar radiation incident on the collector 1, between 90° and, depending on the value of the angle α retained, between 30° and 55° are able to reach, directly or by reflection on the second portion of wall 24, a tube 8 housed in a groove 7 of a collector installed vertically on a facade. This has been shown in figures 5 and 6. In short, the solar radiation is likely to be captured optimally by an exchanger tube 8 whether in winter all day or in the morning and evening in summer.

[0043] Conversely and as [Fig.6] wishes to illustrate, when the sun is at its zenith in summer and forms a smaller angle, depending on the case of 30 or 55° relative to the plane of the sensor 1 in a vertical position on a facade, they no longer reach the tube 8 and are even rejected by reflection on the lower wall 21, extending perpendicular to the bottom wall 19 of a groove 7. Such a configuration makes it possible to avoid overheating of the heat transfer fluid conveyed in the tubes 8 during these summer periods.

[0044] In the case of a panel 2 made from a block of expanded insulating material, preferably of parallelepipedal shape, the rear face and the periphery of which respectively define the rear wall 3 and the peripheral wall 4, the grooves 7 and the intercommunication clearances 11, 12 in the enclosure 5 may result from an operation of notching the front face 25 of the panel 2 in the shape of this block of expanded insulating material.

[0045] The panel 2 can also be obtained by a molding process, for example by injection into a mold of expandable synthetic material from which results the final shape of the panel 2, with, on the front face 25, the grooves 7 according to the invention and the intercommunication clearances 11, 12, just as it is conceivable that this panel 2 is the result of a combination of the two processes: molding and notching.

[0046] According to another embodiment, in the bottom 26 of the enclosure 5 of a panel 2, comprising a rear wall and a peripheral wall 4 made of expanded insulating material, are glued separating walls 27 delimiting between them the grooves 7. Such a separating wall 27 in the form of a profile, preferably made of expanded insulating material, comprises an upper wall intended to define the lower wall 21 of a first groove 7 and a lower wall designed to define the upper wall 20 of a second groove 7 located under the first groove 7. This lower wall of such an intermediate wall 27 is consequently broken down into a first wall portion 23 and a second wall portion 24 forming an angle α of between 35 and 60° relative to the first wall portion 23.

[0047] Preferably, the front face of the panel 2 is treated in white color, for example by applying a white paint to promote the reflection of solar radiation.

[0048] [Fig. 3] represents a sectional view of a portion of tube 8 of exchanger 9 of the device according to the invention. This tube 8 comprises corrugations 28 over all or part of its length. As illustrated in this [Fig. 3], a corrugation 28 forms a peripheral protuberance on the external side of the tube 8 and a hollow annular recess on the internal side of this tube 8.

[0049] Such corrugations 28 increase the absorption surface of the light rays and provide greater resistance to frost through a large expansion capacity of this tube 8. Thanks to this particularity, water can be used as a heat transfer fluid passing through the tube(s) 8 of the exchanger 9, even in regions subject to winter periods with a risk of frost.

[0050] Advantageously, said tube 9 is black in color in order to allow better absorption of light radiation. According to another embodiment, an absorber can be placed in front of a tube 8.

[0051] In particular, as tube 8 of exchanger 9, a corrugated polyethylene tube, of the ICTA electrical sheath type, can be used.

[0052] The solar thermal collector 1 according to the invention also comprises a transparent front wall 6. More particularly, it is defined by a transparent synthetic film or tarpaulin resistant to UV rays of the polyethylene film or tarpaulin type or similar.

[0053] Advantageously, the solar thermal collector 1 comprises an envelope defined by a transparent film or tarpaulin resistant to UV and at the same time designing the transparent front wall 6.

[0054] A transparent film or tarpaulin has the advantage of making the solar thermal collector 1 waterproof at low cost and with low weight. This film or tarpaulin can be heat-shrunk onto the panel 2 or glued to the walls of the latter to limit air movement in the enclosure 5.

[0055] According to another characteristic, the solar thermal collector comprises fixing means (not shown) designed to attach it vertically to the facade of a building. These fixing means may comprise first attachment means directly associated with the rear wall 3 of the panel 2 and second attachment means designed to be fixed to said building facade and with which the first attachment means are intended to cooperate.

[0056] Such fixing means can obviously take other forms of embodiment, for example that of support consoles in the form of cradles defined to be fixed on the construction and designed to receive the solar thermal collector 1.

[0057] Note that the circulation of the heat transfer fluid in the heat exchanger 9 can be ensured simply by thermosiphon or by means of a suitable circulator.

[0058] The advantages resulting from the present invention consist in that this solar thermal collector is of simple design and above all of low weight capable of being implemented on the facade of a building, a much simpler and easier installation than a roof installation.

Claims

Claims

1. Thermal solar collector (1) in the form of a panel (2) comprising a rear wall (3) and a peripheral wall (4) delimiting an enclosure (5) closed by a transparent front wall (6), in the enclosure (5) extending at least one tube (8) of a heat exchanger (9) crossed by a heat transfer fluid between at least one inlet (13) and at least one outlet (14), the rear wall (3) and the peripheral wall (4) being made of an expanded insulating material, in the enclosure (5) being provided at least one groove (7) of adjusted section for housing a tube (8) of the exchanger (9), a groove 7 being delimited by a bottom wall (19) from which extends an upper wall (20) and a lower wall (21), these respecting a spacing (22) of width adjusted tightly to the section of a tube (8), characterized in that that the upper wall (20) of a groove (7) comprises, starting from the bottom wall (19),a first wall portion (23) perpendicular to this bottom wall (19) and extended by at least a second wall portion (24) widening out to form an angle (a) of between 35 and 60° relative to the first wall portion (23).

2. Solar thermal collector (1) according to claim 1, characterized in that the panel (2) is defined in the shape of a rectangular parallelepiped for vertical installation and comprises an upper longitudinal edge wall (15), a lower longitudinal edge wall (16) and vertical lateral edge walls (17, 18) designing the peripheral wall (4), as well as a rear wall, defined vertically, (3), the groove(s) (7) extend in the enclosure (5) horizontally, longitudinally and parallel between the upper longitudinal edge wall (15) and the lower longitudinal edge wall (16).

3. Solar thermal collector (1) according to claim 1 or 2, characterized in that in the enclosure (5), at the ends of the grooves (7), intercommunication clearances (11, 12) are provided extending parallel to the vertical lateral border walls (17, 18).

4. Solar thermal collector (1) according to any one of the preceding claims, characterized in that the panel (2) is made from a block of expanded insulating material.

5. Solar thermal collector (1) according to any one of the preceding claims, characterized in that the panel (2) is obtained by injection molding of expandable synthetic material.

6. Solar thermal collector (1) according to any one of the preceding claims, characterized in that the front face (25) of the panel (2) is treated in white color.

7. Solar thermal collector (1) according to any one of the preceding claims, characterized in that the tube (8) comprises corrugations (28) over all or part of its length, a corrugation (28) forming a peripheral protuberance on the external side of the tube (8) and a hollow annular recess on the internal side of this tube (8).

8. Solar thermal collector (1) according to claim 9, characterized in that the tube (8) is a corrugated polyethylene tube, of the ICTA electrical sheath type.

9. Solar thermal collector (1) according to any one of the preceding claims, characterized in that the transparent front wall (6) is defined by a transparent UV-resistant synthetic film or tarpaulin, of the polyethylene film or tarpaulin type or the like.

10. Solar thermal collector (1) according to any one of the preceding claims, characterized in that it comprises an envelope (29) defined by a transparent UV-resistant film or tarpaulin and designing the transparent front wall 6.

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