GB1577453A

GB1577453A - Solar energy panel

Info

Publication number: GB1577453A
Application number: GB46571/77A
Authority: GB
Original assignee: Industrie Pirelli SpA; Pirelli SpA
Current assignee: Industrie Pirelli SpA; Pirelli and C SpA
Priority date: 1976-11-15
Filing date: 1977-11-09
Publication date: 1980-10-22
Also published as: SE7712782L; FR2370934A1; FR2370934B1; ES232070Y; DE2750602A1; IT1064032B; JPS5362241A; AR221689A1; JPS628699B2; ES232070U

Description

(54) SOLAR ENERGY PANEL (71) We, INDUSTRIE PIRELLI SpA, an Italian Company of Centro Pirelli, Piazza Duca D'Aosta No 3, Milan 20100, Italy, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a solar energy panel and in particular to a panel enabling solar energy to be converted into thermal energy.

Numerous types of solar energy panels have been proposed, but have not, in practice, enjoyed a wide commercial market, since most known panels are not particularly versatile and tend moreover to be fragile and expensive.

The object of the present invention is the provision of a solar energy panel enabling solar energy to be converted into thermal energy which is transferable outside the panel, the panel being efficient, cheap and of simple construction, so that it does not require the services of specialist operators for its installation or maintenance.

Accordingly, the present invention provides a solar energy panel, the panel comprising at least one plate made of a black elastomeric or plastics material, each said plate having (a) at least one internally-disposed fluid passageway extending parallel to a major face of the plate and (b) a projection on each of two opposite edges of the plate, each projection extending normally from one face of the plate, a sheet of a transparent material being supported above said projections to define a closed space between the sheet of transparent material and the plate, one or more header conduits extending in a direction perpendicular to the passageway or passageways and being in communication therewith, and means, associated with each plate, to hold two or more plates in side-by-side abutment, in which the means to hold two or more plates in side-by-side abutment comprises a shaped strip of elastomeric material adapted to engage the projections on each adjacent pair of edges of said plates.

A solar energy panel in accordance with the present invention may comprise: - a plate of black elastomeric material in which there is disposed at least one passageway which extends parallel to a major face of the plate; - a projection on each of two opposite edges of the plate, the projections being made of an elastomeric material, and extending normally relative to a major face of the plate; - a sheet of transparent material, supported by its edges above said projections so as to define a closed space between said sheet and the plate; - a conduit extending in a direction perpendicular to the passageway or passageways and being in communication with said passageway or passageways and with the surroundings; means, associated with each plate, to hold two or more plates in side-by-side abutment; - -means capable of varying the flexibility of the panel in a direction parallel to a major face of the plate.

Plates of elastomeric material and containing at least one passageway, for use in accordance with the present invention, may conveniently be produced by extrusion.

Panels according to the present invention will be illustrated, merely by way of example, in the following description and with reference to the accompanying drawings. In the drawings: Figure 1 is a perspective view of a length of a solar energy panel in accordance with one embodiment of the present invention; Figure 2 is a section on line II-II of Figure 1; Figure 3 is a section on line III-III of Figure 1; Figure 4 is a section through an alternative arrangement to that shown in Figure 1; Figure 5 is a perspective view of a length of a solar panel in accordance with a second embodiment of the present invention; Figure 6 is a section on line VI-VI of Figure 5; and Figure 7 is a section on line VII-VII of Figure 5.

Referring to Figures 1, 2 and 3, the solar energy panel comprises a plate of black elastomeric material, made by joining several profiled sections 1 by their adjacent edges.

Each profiled section 1 consists of a plate of black elastomeric material obtained by extrusion, in which there are several internally-disposed passageways 2, the passageways extending parallel to the faces of the profiled section and having their axes parallel and coplanar relative to one another.

In the profiled section 1 there are also several reinforcing threads 3, whose axes are coplanar and parallel relative to one another. The threads may be incorporated in the mixture of elastomeric materials used to make the profiled sections 1 so as to be parallel to the axes of the passageways and to be in proximity to the face 4 of the profiled section.

These edges of each profiled section which are parallel to the axes of the passageways are provided with projections 5, extending from face 6 of the profiled section. The projections 5 have, in transverse section, the shape of a rectangular trapezium whose shorter parallel side abuts face 6 of profiled section 1, and whose side perpendicular to said shorter parallel side constitutes an extension of edge 7 of the profiled section 1.

Several profiled sections 1 are joined side-by-side to make the plate of the solar energy panel. For this purpose, profiled sections 1 are positioned side-by-side so that the edges 7 abut. When the two profiled sections 1 are placed side-by-side (see Figure 2), projections 5 of each adjacent pair of profiled sections form a dovetail-shaped rib.

The dovetail-shaped rib engages a complementary cavity 8, in a shaped strip 9 of an elastomeric material, to join each adjacent pair of profiled sections 1.

In that part of the shaped strip 9 remote from profiled section 1, two slots 10 are provided, to receive the edges of a sheet 11 of transparent material, so as to define a space 12 between the profiled section 1 and the sheet 11.

Referring now to Figures 3 and 4, each profiled section 1 is provided with perpendicular to the axes of passageways 2, there is provided both a tightening system 13 and a conduit 14, the conduit extending between the shell of profiled sections 1, so as to lie perpendicular to the axes of passageways 2. Each conduit 14 has in its walls several apertures 15, and one aperture coincides with an end of each passageway.

Each tightening system consists of an L-shaped member 16, having a first flange 17, a web 18 and a second flange 19 which is movable relative to the first flange 17 along the axis of web 18. The flanges 17 and 19 each have several through holes 20, into which bolts 21 can be inserted. In addition, each tightening system includes a shaped strip 22, made in an elastomeric material and provided with a groove 23.

The tightening system 13 together with the threads 3 incorporated in profiled section 1, forms means capable of varying the flexibility of the solar energy panel in accordance with the present invention, in a direction parallel to a major face of the plate.

Figure 3 shows a panel in accordance with one embodiment of the present invention, wherein the tightening system 13 acts to stiffen the panel.

As can be seen in Figure 3, the shaped strip 22, which supports the edges of sheet 11 of transparent material, is disposed between flanges 19 and 17 of the L-shaped member 16; and, in addition, those edges of profiled section 1 which do not carry projections are held between the flange 17 and the shaped strip 22 by bolts 21. When the profiled section 1, in which threads 3 are incorporated and the sheet of transparent material are connected in this way, a substantially rigid structure is produced.

Figure 4 shows a panel in accordance with a further embodiment of the present invention, in which the profiled section 1 and the sheet 11 of transparent material are free to deform relative to each other. This is achieved as follows: Between the flanges 17 and 19 there is disposed only the end of the profiled section perpendicular to the axes of the passageways, and the bolts 21 tighten said flanges 17 and 19. The shaped strip 22 is supported above flange 19.

In Figures 5, 6 and 7 there is shown a panel in accordance with a further embodiment of the present invention, in which the panel consists of a profiled section 24, which is made of a mixture of elastomeric materials and is provided with several passageways 25, the axes of which are coplanar and parallel relative to one another. In the profiled section 24 there are incorporated several reinforcing threads 26 which are in proximity to face 27 of the profiled section. Also on those edges of profiled section 24 which are parallel to the axes of passageways 25 there are provided projections 28, having the shape of a rectangular trapezium, which extend from face 29 to the profiled section so as to form a dovetail-shaped rib when two profiled sections 24 are placed side-by-side.

The dovetail-shaped strip 31, (which is the face remote from the profiled sections) there is provided a slot 33 communicating with a cavity 34. Within the cavity 34 there is located a rod 35. A sheet 36 of transparent material is disposed between the tops of adjacent shaped strips 31 and passes within the slots 33, and is wound round rod 35.

At the edges of each profiled section perpendicular to the axes of the passageways (see Figure 7), members 37 are provided. Each member 37 is E-shaped in the section perpendicular to its major dimension, and consists of a web 38 and three flanges 39, 40 and 41. Between the flanges 39 and 40 there is sealed, (for example, by means of an adhesive) the edge of a profiled section, and the sealed insertion is such as to define a conduit 42 into which the passageways emerge. On flange 41 of the E-shaped member 37 there is laid a sheet 36 of transparent material.

The passageways in a panel according to the present invention have important characteristics contributing to the objects of the present invention.

The passageways are, in the section perpendicular to their major dimension, of quadrilateral shape, and have two sides parallel to the faces of the profiled section. The thickness of the elastomeric material which separates the passageways from the surface of that section facing towards the closed space is between 0.3 to 3 mm, and is preferably between 0.5 and 1.2 mm, so that the surface is elastically deformable.

The dimensions of each passageway in the direction of the thickness of the profiled section are between 2 and 20 mm, preferably between 5 and 10 mm. (These dimensions have been deduced empirically). The thicknesses of the walls separating adjacent passageways have also been deduced empirically and such thicknesses are between 0.3 and 3 mm, preferably between 0.5 and 1 mm.

In the direction parallel to the faces of the profiled section, the passageways have no critical dimensions, and there are also no critical values for the thickness of elastomeric material present between the passageways and the face of the profiled section remote from the closed space.

The operation of a panel in accordance with the present invention will now be described with reference to Figures 1, 2 and 3.

The panel is placed so as to receive incident sunlight on the sheet of transparent material, and into one of the two conduits 14 there is introduced a fluid under pressure, for example, water. The fluid passes from one conduit 14 into passageways 2 and emerges from the panel through the other conduit 14.

When the fluid enters the passageways, deformation occurs in the walls separating such passageways from surface 6 of the panel; the surface 6 thus assumes a wavy configuration, which has been found to optimise absorption of energy.

Energy obtained from incident solar radiation, passing through the sheet of transparent material on surface 6 of the profiled section causes the material from which the latter is made to be heated, and the heat is transmitted to the fluid flowing in the passageways. Air present in the closed space thermally insulates the profiled section, preventing heat losses by conduction and convection, and the sheet of transparent material (e.g. glass) prevents heat losses in the form of infra-red radiant energy emitted by the profiled section, (greenhouse effect).

Tests have been carried out with a panel in accordance with the invention. For the tests, a panel was used which consisted of two profiled sections. The dimensional characteristics of the panel used for the tests were: - length of each profiled section 2.5 m - width of each profiled section 0.5 m - number of passageways 50 - thickness of layer of separation of passageway from surface on which sunlight fell 1 mm - thickness of layer separating two adjacent passageways 2 mm - distance between glass and surface of profiled section on which sunlight fell 2.5 cm - thickness of glass 4 mm - total area of panel on which sunlight fell 2.5 m2 One of the two following mixtures (a) or (b) was used to make the profiled sections: (See last paragraph of specification) (a) - Neoprene W (1) 70 parts by weight - Neoprene WB (2) 30 parts by weight - Zinc oxide 5 parts by weight - Magnesium oxide 4 parts by weight - Sulphur from 0.5 to 1.5 parts by weight - Di-o-tolyguanidine 1 part by weight - Tetramethylthioureamonosulphide 0.5 parts by weight - Stearic acid 1 part by weight - F E F black (3) 60 parts by weight - Naphtha plasticiser 10 parts by weight - Antioxidant 2 parts by weight (b) - EPDM (4) 100 parts by weight - Zinc oxide 5 parts by weight - Sulphur 1.5 parts by weight - Mercaptobenzothiazole 1.5 parts by weight - Tetramethylthioureamonosulphide 0.5 parts by weight - Stearic acid 1 part by weight - Naphtha oil 30 parts by weight - FEF black (3) 80 parts by weight - Antioxidant 1 part by weight Tests were carried out by introducing into the panel water at 27"C at a flow of 330 g/minute, and the middle hours of the day in the summertime were used for the tests.

The results of the tests were as follows: - Temperature of water at outlet 80"C - Total absorbed power 1240 W - Absorbed power per unit area 492 W/m2 - Efficiency 62% Panels in accordance with the present invention are obtained by joining, by simple means, several prefabricated elements, the length of which may be varied if required. In this way it is possible to make up a panel of any shape and dimensions. This gives the panel considerable versatility. This versatility is also increased by the availability of means to vary the stiffness in said panel. In this way, it is possible to cover with the same panel, a continuous area which is not flat (for example, wavy), or to use the panel to cover an "open" area without the need for a support.

In addition, the simplicity of the elements making up the panel enable it to be fitted and maintained by non-specialist operators.

Finally, the panel in accordance with the invention has a high efficiency, as demonstrated by the experimental results previously mentioned.

The numbered ingredients are further identified as follows: (1) Neoprene W A "general-purpose" neoprene polymer (2) Neoprene WB : A neoprene polymer containing a high proportion of cross-linking agent : generally used as part of a blend with other neoprenes.

(3) FEF black Fast extrusion furnace black, a carbon black of average particle size 0.05 microns.

(4) EPDM Ethylene-propylene-diene monomer.

WHAT WE CLAIM IS: 1. A solar energy panel, the panel comprising at least one plate made of a black plastics or elastomeric material, each said plate having (a) at least one internally-disposed fluid passageway extending parallel to a major face of the plate, and (b) a projection on each of two opposite edges of the plate each projection extending normally from a major face of the plate, a sheet of a transparent material being supported above said projections to define a closed space between the sheet of transparent material and the plate, one or more leader conduits, each conduit extending in a direction perpendicular to the passageway or

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. One of the two following mixtures (a) or (b) was used to make the profiled sections: (See last paragraph of specification) (a) - Neoprene W (1) 70 parts by weight - Neoprene WB (2) 30 parts by weight - Zinc oxide 5 parts by weight - Magnesium oxide 4 parts by weight - Sulphur from 0.5 to 1.5 parts by weight - Di-o-tolyguanidine 1 part by weight - Tetramethylthioureamonosulphide 0.5 parts by weight - Stearic acid 1 part by weight - F E F black (3) 60 parts by weight - Naphtha plasticiser 10 parts by weight - Antioxidant 2 parts by weight (b) - EPDM (4) 100 parts by weight - Zinc oxide 5 parts by weight - Sulphur 1.5 parts by weight - Mercaptobenzothiazole 1.5 parts by weight - Tetramethylthioureamonosulphide 0.5 parts by weight - Stearic acid 1 part by weight - Naphtha oil 30 parts by weight - FEF black (3) 80 parts by weight - Antioxidant 1 part by weight Tests were carried out by introducing into the panel water at 27"C at a flow of 330 g/minute, and the middle hours of the day in the summertime were used for the tests. The results of the tests were as follows: - Temperature of water at outlet 80"C - Total absorbed power 1240 W - Absorbed power per unit area 492 W/m2 - Efficiency 62% Panels in accordance with the present invention are obtained by joining, by simple means, several prefabricated elements, the length of which may be varied if required. In this way it is possible to make up a panel of any shape and dimensions. This gives the panel considerable versatility. This versatility is also increased by the availability of means to vary the stiffness in said panel. In this way, it is possible to cover with the same panel, a continuous area which is not flat (for example, wavy), or to use the panel to cover an "open" area without the need for a support. In addition, the simplicity of the elements making up the panel enable it to be fitted and maintained by non-specialist operators. Finally, the panel in accordance with the invention has a high efficiency, as demonstrated by the experimental results previously mentioned. The numbered ingredients are further identified as follows: (1) Neoprene W A "general-purpose" neoprene polymer (2) Neoprene WB : A neoprene polymer containing a high proportion of cross-linking agent : generally used as part of a blend with other neoprenes. (3) FEF black Fast extrusion furnace black, a carbon black of average particle size 0.05 microns. (4) EPDM Ethylene-propylene-diene monomer. WHAT WE CLAIM IS:

1. A solar energy panel, the panel comprising at least one plate made of a black plastics or elastomeric material, each said plate having (a) at least one internally-disposed fluid passageway extending parallel to a major face of the plate, and (b) a projection on each of two opposite edges of the plate each projection extending normally from a major face of the plate, a sheet of a transparent material being supported above said projections to define a closed space between the sheet of transparent material and the plate, one or more leader conduits, each conduit extending in a direction perpendicular to the passageway or

passageways and being in communication therewith, and means associated with each plate, to hold two or more plates in side-by-side abutment, in which the means to hold two or more plates in side-by-side abutment comprises a shaped strip of elastomeric material adapted to engage the projections on each adjacent pair of edges of said platens.

2. A panel according to Claim 1, including means to vary the flexibility of the panel.

3. A panel according to Claim 1 or 2, in which the elastomeric or plastics material constituting each plate is elastically deformable.

4. A panel according to Claim 3, in which the the passageway or passageways and the surface of the plate from which the projections extend are separated by a sheet of elastomeric material having a thickness of from 0.3 mm to 3.0 mm.

5. A panel according to Claim 4, in which the sheet of elastomeric material has a thickness of between 0.5 mm and 1.2 mm.

6. A panel according to any one of the preceding claims, in which the thickness of the material which separates two contiguous passageways is between 0.3 mm and 3 mm.

7. A panel according to Claim 6, in which the thickness of the material which separates two contiguous passageways is between 0.5 mm and 1 mm.

8. A panel according to any one of Claims 2 to 7, in which the means to vary the flexibility of the panel consist of several reinforcing threads incorporated in each plate and a tightening system located at the edge of each plate, each said system being disposed perpendicular to the axes of the passageways.

9. A solar energy panel, substantially as hereinbefore described, with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.

10. A solar energy panel, substantially as hereinbefore described, with reference to and as illustrated in Figures 5, 6 and 7 of the accompanying drawings.