WO2009081439A2

WO2009081439A2 - Module of solar collector for the composition of thermal and/or photovoltaic roofs

Info

Publication number: WO2009081439A2
Application number: PCT/IT2008/000762
Authority: WO
Inventors: Gianfranco Bonomi
Original assignee: Five T S.R.L.
Priority date: 2007-12-21
Filing date: 2008-12-15
Publication date: 2009-07-02
Also published as: WO2009081439A9; WO2009081439A3

Abstract

This invention concerns a solar collector module for the formation of a thermic or photovoltaic roof, comprising a collector/thermal exchanger (11 ) between a supporting structure (12, 20, 26) and a possible sheet of transparent covering (35). The collector/exchanger is made up of an aluminium or similar solar picking up plate (14) forming one or more longitudinal ducts (16) for the circulation of a thermovector fluid. The supporting structure comprises at least two parallel supporting wood beams (12), each one fitted with a rigid metal profile (20) extending along the top side of the beam and anti-flexion lateral tie rods (26). The plate (14) rests and is fixed above the metal profiles (20) along the beams (12) and on at least a layer of thermo isolating and transparent material (13', 13') positioned between and to the sides of said beams.

Description

"MODULE OF SOLAR COLLECTOR FOR THE COMPOSITION OF

THERMAL AND/OR PHOTOVOLTAIC ROOFS "

* * *

Field of the Invention The present invention concerns in general the collector or solar modules field, both thermal for the production of hot water for sanitary and/or heating purposes, and photovoltaic for the production of electric energy. In particular however, the invention regards a solar collector module directly usable as a component for the formation of a solar and/or photovoltaic roof. State of the technique

The solar modules or collectors represent a valid system for a fruitful exploitation of renewable energy, such as solar energy, attained by converting it into thermal or electric energy. Usually the solar thermal modules or panels comprise a frame or support holding a thermal collector/exchanger provided with tubes in which a thermovector fluid circulates from and to a tank containing the fluid to be heated, usually water, and may have a possible transparent cover over the collector/exchanger.

The photovoltaic panels or modules have a similar structure, but carry and use a number of photovoltaic cells in connection with an electric circuit instead of a thermal collector/exchanger.

The solar modules or panels, both thermal and photovoltaic, can be installed on the ground or on the roofs of buildings, facing though towards the sun and/or placed on automatically adjusting systems. When installed on roofs, they become autonomous components that are added or are inserted in the roofing using auxiliary structures which are aesthetically unpleasant, and which allow limited covering of the surfaces so as not to encumber the usual structure of the roof.

Objects and Summary of the Invention

One object of this invention is to avoid the drawbacks given above and to provide for this reason, a solar thermal and/or photovoltaic panel configured as a very rigid module and of considerable lengths, to be used in combination with other similar modules to form a self-supporting extended structure, not so as to be fixed to the roofs in the traditional way, but suitable to become in themselves and directly roofs for buildings, in place of the usual coverings for roofs.

Another object\ of the invention is therefore to create the conditions for the construction of roof coverings which use solar modules or panels able to produce either thermal or electric energy, as an alternative or in combination, resulting in the fact that the roofs can be built perfectly insulated, with all the safety characteristics and at the same time with the optimal thermo-hygrometric prerogatives of transpiration and aerification. An additional object of the invention is to facilitate, by approaching several thermal solar modules or panels, the construction of large tapping surfaces to be able in this way to provide for the considerable thermal energy needs for heating, in particular when a stratified fluid accumulation system is available, above all with the possibility of getting cooler water to circulate in the panels during the hotter periods. These objects and implicit advantages that derive from them are reached in a solar collector module that basically comprises a thermal collector/exchanger made up of an aluminium or similar solar picking up plate forming one or more longitudinal ducts for the circulation of a thermovector fluid and having a front surface exposed to solar radiations, and a supporting structure consisting of at least two parallel wooden or similar beams, each one provided with a rigid metal profile extending along the top side of the beam and lateral anti-flexion lateral tie rods, and where said plate is resting and fixed on the metal profiles extending along said beams and insulated on its rear side by at least a layer of thermo-insulating and transpiring material placed between and on the sides of said beams.

In the same way photovoltaic panels or modules or, even hybrid, thermal or photovoltaic modules or panels can be set up to manufactured for the production both of thermal and electric energy in the same application area and with the thermovector fluid circulating in the solar panel that helps to cool the photovoltaic panel at the highest temperatures when necessary. Brief Description of the Drawings

Greater details will however become evident from the following description referring to a solar thermal collector andjnade in reference to the enclosed, indicative and not limiting drawings, in which:

Fig. 1 is an end view of the solar picking up plate for a thermal collector/exchanger according to the invention,

Fig. 2 is a side view of the assembled solar collector module;

Fig. 3 is an enlarged view of the circled detail in Fig.2; Fig. 3a is a detail of a variant of the whole in Fig. 3; Fig. 4 is a view in perspective of a foreshortening of the solar collector module in Fig. 3;

Fig. 5 is an enlarged cross section in the direction of arrows A-A in Fig. 2; Fig. 6 is an element to hold a tension rod in position at the side of each beam;

Fig. 7 is a section of a detail according to arrows B-B in Fig. 4;

Fig. 8 is a plan view of several solar collector modules assembled side by side to form a covering for roofs; Figs. 9 and 10 are, respectively, a view in perspective and a partial longitudinal section of the solar modules associated with the eaves gutter;

Fig. 11 shows, schematically, an example of the laying of several solar modules to construct a solar roof; and

Fig. 12 shows a longitudinal section of two solar modules positioned to form a pitched roof.

Detailed Description of the Invention

As shown, the solar collector module according to the invention basically comprises a solar thermal collector/exchanger module 11 mounted on parallel supporting beams 12 and insulated on its rear side by one or more layers of thermo-insulating and transpiring material 13.

The thermal collector/exchanger -Fig. 1- is made up of a metal plate

14 , preferably aluminium or one of its alloys, having a basically flat front surface 15 and on its rear side one or more ducts 16, that extend for the whole of its length and which are designed for the circulation of a thermovector fluid. Said longitudinal ducts 16 can be with circular sections, but preferably they will be elliptical with a major axis parallel to the front face of the plate to benefit from more light and greater heat exchange surface without the plate itself influencing the thickness. Furthermore, in a crosswise direction, the solar picking up plate 14 has preferably a variable thickness in the fact that it lessens starting from the opposite sides of each longitudinal duct towards the parallel duct and from ducts towards the longitudinal sides of the plate 14. Along these longitudinal sides two wings 17 are provided, which protrude from the front surface 15 of the plate 14. In addition said plate may be provided with a series of ribs 18 protruding from its rear face, extending for all its length and each one provided with end support tabs 19, basically T shaped, preferably channel shaped, to facilitate the evacuation of possible condensation water.

The length of the metal plate 14 forming the thermal collector/exchanger will be chosen based on the sight size to be covered and can vary quite a lot. So, the length of said plate may be in the order of several metres long, for example from 4-6 metres up to 12 metres and more, whereas its width can be in the order, for example, of 50 to 60 cm.

As stated above, the plate 14 rests on supporting beams 12 which in^ the example illustrated are three, have a rectangular section, a constant width, with the major axis vertical and preferably made of plywood. However, the plate 14 does not rest directly on the supporting beams 12, but through rigid intermediate profiles 20, made of metal, preferably steel. As shown, each intermediate profile 20 has a basically "omega" (Ω) section and is positioned above the top side of the respective beam 12 for all the length of the latter, and it conjugates with two tongues tabs of adjacent ribs 18 emerging from the rear face of the plate 14 as shown in Fig. 5.

The bottom sides of the supporting beams 12 can be associated with a base plane 21 acting as a finishing element and for example, made of plywood. Said base plane 21 has longitudinal grooves 21' connecting with the lower sides of said beams 12 and can be fixed to the plate 14 by means of connecting rods 22 each having, at the top, a threaded portion 23 that connects to a nut 24, placed between the ribs 18 below of said plate and held in position by a spring 24', and lower, a ledge head 25 that rests against said base plane 21 , preferably recessed. The thermo insulating/transpiring material 13 is positioned and held between the base plane 21 and the upper plate 14, in the spaces between the supporting beams 12 and the sides of the latter. Preferably the thermo insulating/transpiring material can be made up of one or more layers of polystyrene 13' and cork 13", the latter adjacent to the plate 14 and the sides of the lateral beams, that also carry out the function of soundproofing.

The presence of intermediate metal profiles 20 between the solar picking up plate 14 and each supporting beam 12 already supplies good rigidity to the structure of the collector module against the flexion due to its own weight when its ends are resting and against external encumberingloads and agents. However, to ensure maximum rigidity, of the whole, in particular for the longer solar collector modules, each of the opposite sides of each supporting beam 12 is associated with an anti-flexion tie rod 26 in the shape of a steel rod or cord, positioned so as to design a parabolic curve formed by stop brackets 27 positioned at a distance one from the other and fixed to the side of the beam, as shown in Fig. 2 and more in particular in Figs 4 and 7. The stop brackets 27 are shaped so as to form a slightly curved rest plane 27' for the tie rod 26 and to hold the latter in the correct position, allowing it to slide freely however.

The ends of each tie rod 26 have a threaded portion 28 -Fig. 3 - and the end of each supporting beam 12 is associated with a contrast bracket 29, basically an inverted L shape, that rests against the end of the profile 20 associated with the same beam. The threaded terminal portions 28 of each tension rod 26 extend into corresponding bore holes provided in the contrast plates 29 where they are blocked by tightening nuts 30 so as to place the tie rod under traction according to needs. On the other side, the profile 20 to which the contrast brackets rest against 29 will be compression loaded, giving the solar collector module as a whole a high level of firmness and high resistance to flexion even when it is particularly long and is used under variable loads. In other words the profiles 20 and the tie rod 26 associated with the beams will form a highly resistant tensio-compression structure that assures the rigidity and stability of the collector module even when it is very long.

A similar result can be achieved by associating an transverse attachment member 29' with each end of the profile 20, by inserting the threaded terminal portions 28 of the tie rods 26 into corresponding bore holes 29" provided in said attachment member 29', blocking them using tightening nuts 30 as shown in the detail in Fig. 3a.

The collector module made in this way can be assembled side by side with other similar modules connecting them by means of their lateral wings 17 using appropriate profiles 31 and by the insertion of sealing joints 32 -Fig. 5. Where required, above each solar picking up plate 14 a protective covering 35 may be located of toughened glass, polycarbonate or some other material can be provided, as long at is transparent, supported between the wings 17 of the plate by the same connecting profiles side by side of the modules. The free ends of each module will be conveniently plugged for example by a plywood plane, leaving however the ends of the ducts of the plate exposed.

Also possible will be the construction also roof coverings by laying the panels on ridge 33 and edge beams 34, -Fig. 8- with the insertion of viscous-flexible joints -not shown- able both to allow from time to time the choice and the adjustment of the slope of the covering to be carried out, and to support and amortise the external stress, including earth tremors. The resulting roof will form a large sized solar collector, in which the ends of the ducts of the individual modules will be connected to some collectors 36 for a circulation of thermovector fluid in the ambit of a circuit for heating of a liquid, typically water.

It should be understood that to construct coverings, that is roofs, of different sizes the same components can be used, such as the solar picking up plate, the rigid profiles and the tie rods, except for the wooden beams which, given the thickness, vary in height in relation to the span and to the load to support.

Basically the elements that support the stress due to the weight of the module and to the external loads, such as snow, wind, etc., are only the "omega" shaped profiles under compression stress and the tie rods under tensile stress. The parabolic arrangement of the tie rods avoids having shearing stress; the other components of the module, such as the solar picking up plate, the beams and the insulating material, as regards to the strain, only carry out complementary functions, ensuring the stability of the loads combined bending and compressive loads and therefore preventing lateral deformations. Furthermore the almost ideal flexible behaviour of the steel forming the "omega" shaped profiles and the tie rods ensure the recovery of each momentary flexion and consequently the absence of permanent flexions, whereas the other aluminium, wooden and insulating material components carry out damping and contrast functions against the tendency to oscillate, otherwise typical of constructions merely made out of steel.

Furthermore, and even when the modules have been layed in place, it will always be possible to change and register the tensile stress of the tie rods by using the tightening nuts depending on the real stress conditions that occur from time to time.

A similar structure with equivalent results will be applicable also for photovoltaic collectors in which the solar picking up plate will act as a support for the photovoltaic cells, with the possibility in addition of cooling the system with a fluid flowing in the ducts of said plate. The invention described above is therefore particularly advantageous in that it allows the modular formation of real roofs even with large spans, in any case complete with what may be necessary, starting from a well structured self-supporting solar collector module , thermically insulated, transpiring, ventilated, sound proofed, aseismatic, long lasting. Furthermore, each roof can be entirely composed of thermal solar modules for the production of hot water, of photovoltaic solar modules for the production of electric energy, or partly thermal modules and partly photovoltaic collector modules.

The roof can be made locally and/or in substitution of the traditional roofs and called "solar roof. Anyway it responds to the characteristics, safety rules, carrying capacity and static requirements in force regarding roofs and building coverings.

When the roof is pitched (Figs. 11 , 12), at their summit the modules can be joined using tie rods 37 and protected with a covering element 38 in correspondence with which can be provided possible aeration openings 39 to allow, where necessary, a ventilation of the solar roof so as to avoid overheating and/or the formation of humidity.

The roof may also be completed in its lower half (Figs. 9, 10) with trough gutters 40, anchored to the solar modules by means of supporting straps 41 and in some of its parts by safety elements 42, walkway surfaces, stairs, banisters, circuit breaker, snow stop 43, chimneys/air vents 44 or whatever required anchored to the profiles extending along the wings of the solar panels.

Finally, the plate 11 functioning as a collector or exchanger, possibly without- ant thermal insulation and front covering sheet, even with reduced thermal performance, it can be used for the construction of light roofs or the like.

Claims

"MODULE OF SOLAR COLLECTOR FOR THE COMPOSITION OF THERMAL AND/OR PHOTOVOLTAIC ROOFS "* * *C L A I M S

1. Solar collector module for the construction of a thermal or photovoltaic roof, comprising a thermal collector/exchanger (11) between a supporting structure (12, 20, 26) and a possible transparent covering sheet (35), characterized in that said collector/exchanger consists in an extruded aluminium solar picking up plate (14) forming one or more longitudinal conduits (16) for the circulation of a thermovector fluid, in that said supporting structure comprises at least two parallel supporting wood beams (12), each provided with a rigid metal profile (20) associated with a longitudinal upper side of the beam e with anti-flexion lateral tie rods (26) which respective ends are anchored to the opposite ends of said profile, and in that said plate (14) is resting against and blocked at right angles above the metal profiles (20) associated with said beams (12) and on at least a layer of thermo-insulating and transpiring material (13', 13") placed between and along the sides of said beams.

2. A solar collector module according to claim 1 , wherein the rigid metal profile (20) associated with the longitudinal upper side of each beam (12) is made of steel and has an "omega" shaped section, and wherein the anti-flexion tie rods (26) are formed of steel rod or chords, positioned and extending along the opposite sides and for the whole length of each beam.

3. A solar collector modules according to claim 1 and 2, wherein each anti-flexion tie rod (26) is positioned so as to design a parabolic curve formed by stop brackets (27) positioned at a distance from each other and fixed to the side of each beam; each tie rod (26) has threaded terminal portions (28); at the opposite ends of the rigid metal profile (20) on each supporting beam (12) are associated attachment elements (29, 29') positioned to connect the threaded terminal portions (28) of each tie rod (26) by means of tightening nuts (30) so as to define a system in which the rigid metal profiles (20) associated with the same beam that work under compression and the tie rods (26) under traction.

4. A solar collector module according to claim 3, wherein each attachment element is made up of a contrast plate (29) that joins with a respective end of the rigid metal profile (20) and rests against the adjacent end of the supporting beam (12), said contrast plate having at least one receiver bore hole of a threaded end of every anti-flexion tie rod.

5. A solar collector module according to claim 3, wherein every attachment element is made up of an transverse member (29¹) associated with a respective end of the rigid metal profile (20) and having at least one receiver bore hole to accept a threaded end of each anti-flexion tie rod.

6. A solar collector module according to claims 3 and 4 or 5, wherein said stop brackets (27) are shaped so as to form a slightly curvilinear support surface (27') for the positioning of the respective tie rod (26), and on which the solar picking up plate (14) rests on the metal profiles (20) associated with said beams by means of ribs (18) on a rear face of said plate (14) and provided with longitudinal tabs (19) extending along said ribs.

7. A solar collector module according to claim 1 , wherein said solar picking up plate (14) has a flat front surface (15) and two longitudinally lateral wings (17) that extend upwards from the front surface, and in which said longitudinal ducts (16) have preferably an elliptical section.

8. A solar collector module according to claim 7, wherein in said plate (14) the longitudinal ribs (18) emerge from its rear surface and each terminates in support tabs (19) resting at least on the thermo insulating and transpiring material, and wherein the plate (14) has a variable thickness in its crosswise direction, in particular decreasing starting from the opposite sides of each longitudinal duct towards the parallel duct, and from the ducts towards the longitudinal sides of the plate itself.

9. A solar collector module according to any of the previous claims, wherein the thermo insulating and transpiring material includes at least a layer of polystyrene or the like (13') and a layer of cork (13"), the latter adjacent to the plate (14) and to the sides of the lateral beams, and wherein at the base of said material is provided a finishing surface (21 ) associated with the supporting beams (12) and attached to said plate by means of a connecting rod (22).

10. A solar collector module according to any of the previous claims, wherein the possible transparent covering (35) is positioned and supported between the lateral longitudinal wings (17) of the plate (14) by means of supporting profiles and insertion of seals.

11. A solar collector module according to any of the previous claims, having a length up to 12 or more metres and a length of about 50-60 cm.

12. A solar collector module according to any of the previous claims, which can be placed side by side with other similar collector modules to form a roof, where the modules are connected together by means of profile joints and seals associated with their lateral longitudinal tabs, resting on ridge and connecting beams with the insertion of wince flexible joints, and their longitudinal conduits are connected to fluid collectors.

13. A self-supporting roof for buildings having at least one pitch, characterized in that it comprises a number of solar modules according to any of the previous claims, in line, connected side by side by means of connections and seals at least in correspondence with their adjacent lateral wings (17).

14. Roof according to claim 13, comprising two sloping pitches converging in a summit and where an upper covering element (29) and possible ventilation openings (30) with controlled opening to prevent overheating and/or build up of humidity are envisaged.