ITVE20110014A1 - SOLAR THERMAL COLLECTOR. - Google Patents

Description

DESCRIPTION

of the invention entitled:

"Solar thermal collector"

The present invention relates to a solar thermal collector.

Thermal solar collectors are known, generally consisting of panels to be exposed to solar radiation, which strike an absorbing surface which is in contact with a coil traversed by a heat-carrying fluid, heating it. The heat-carrying fluid thus heated is then sent to an accumulation system of the captured thermal energy, for its deferred use. Thermal solar collectors are also known where the coil is contained within vacuum tubes, to avoid heat dispersion and to increase the efficiency of the system.

Solar thermal collectors of the most varied configurations have already been proposed, which thanks to the continuous progress of research in this sector have led to satisfactory results in terms of efficiency of the transformation of solar energy into directly usable thermal energy.

The purpose of the present invention is to realize a solar thermal collector which, in addition to offering the best performances obtainable today with traditional solar collectors, has a high versatility and flexibility of installation and use and with few modular elements is able to satisfy the multiple needs of different categories of users.

Another object of the present invention is to offer, in its simplest configuration, a low-cost solution, given the reduced number of components that constitute it and the reduced number of processes that its realization involves.

These objects and others that will emerge from the following description are achieved, according to the invention, with a solar thermal collector characterized in that it comprises at least one absorber module, made of extruded material and showing a plurality of ducts intended for the circulation of a heat-carrying fluid , and at least two head elements applicable to the ends of said module for the selective connection of at least one of its ducts with at least another duct of the same or of another module.

The present invention is further clarified hereinafter in some of its preferred embodiments reported for purely illustrative and non-limiting purposes with reference to the attached drawings, in which:

Figure 1 shows a perspective view of a solar thermal collector according to the invention,

figure 2 shows a perspective view of a solar collector in a different embodiment, suitable for exploiting the greenhouse effect, figure 3 shows in perspective view only the absorber module in a different embodiment, also suitable for exploiting the effect greenhouse,

figure 4 shows in perspective view two solar thermal collectors coupled together by means of a lateral junction profile,

figure 5 shows a perspective view of a hybrid solar thermal collector, complete with dissipation module and relative coupling side profiles

Figure 6 shows a perspective view of an absorber module with the direction of circulation of the "spiral" heat carrier fluid highlighted, Figure 7 shows it in the same view as Figure 8 with the direction of circulation of the "coil" heat carrier fluid highlighted,

figure 8 shows it in the same view as figure 6, showing the direction of circulation of the heat transfer fluid with inlet at one end and outlet at the opposite end,

Figure 9 shows a perspective view of a header manifold in a first embodiment without cover and provided with screws for fixing the latter and with locking screws to the absorber module; Figure 10 shows a perspective view of a portion of the header manifold with highlighted the path of the heat transfer fluid,

figure 11 shows it with a first type of cover applied to the base body,

figure 12 shows it with a second type of cover applied to the base body,

Figure 13 is a bottom perspective view of the lid of Fig. 12, figure 14 shows in a perspective view from below a solar collector according to the invention with the absorber module to which a header collector provided with a cover of figs is applied. 12 and 13, Figure 15 shows a perspective view of a header manifold in a second embodiment obtained from an aluminum block subjected to mechanical processing,

Figure 16 is a perspective view of a tile roofing element to which a solar collector according to the invention is applicable; Figure 17 is a perspective view of a hybrid-type solar thermal collector applied to the tile roofing element of Fig. 13, Figure 18 shows a portion of extruded profile, in which the coupling between the absorber module and the heat sink module includes a "thermal break",

figure 19 shows a portion of the solar collector with two differently made head elements, one of which has a base and a lid but without an aesthetic cover, the other also has an aesthetic cover,

figure 20 shows an exploded perspective view of an end portion of a solar collector according to the invention provided at one end with a head element of the type illustrated in fig. 19,

figure 21 shows a portion of the solar collector according to the invention housed in the longitudinal channel obtained inside a row of hollow bent tiles, delimited at the top by transparent covers, figure 22 shows it in an embodiment variant applied to a multifunctional element forming part of a photovoltaic system integrated into a roof,

figure 23 shows it in an exploded perspective view and on a larger scale, figure 24 shows a perspective view of a portion of the solar collector in a still different embodiment, always housed in the longitudinal channel obtained inside the row of tiles, figure 25 the exhibition in an exploded and enlarged perspective view,

figure 26 shows a portion of the solar collector in a variant embodiment of fig. 21 housed in a longitudinal channel delimited by two adjacent rows of tiles,

Figure 27 shows it in an exploded perspective view and on a larger scale, and Figure 28 shows it in an exploded perspective view in a further embodiment, in which the extruded section has a tubular shape with a circular section.

As can be seen from the figures, the solar thermal collector according to the invention comprises a so-called "absorber" module 2, consisting of an extruded profile, preferably of aluminum or other material with high thermal conductivity (for example copper, or also, in the version economic, black plastic material), possibly subjected on the absorbing surface 4, i.e. on the surface that in the installed solar collector is facing the solar radiation, to a surface treatment (for example Tinox or thermally selective paint) aimed at increasing the absorbing capacity of the surface itself.

In addition to the absorbing surface 4, the absorber module 2 comprises a plurality of parallel and preferably equidistant tubular ducts 6, which branch off from the absorbing surface 4 towards the interior of the module and are intended for the circulation of a traditional heat-carrying fluid. This particular realization of the absorber module 2 by extrusion allows to avoid welding / brazing of the tubular ducts 6 to the absorbing surface 4 with considerable economic savings, as well as obtaining a high thermal yield, thanks to the continuity between the absorbing surface 4 and ducts 6 .

Furthermore, this particular embodiment of the absorber module 2 allows the tubular ducts 6 to be made with a diameter much smaller than that required by the tubular ducts to be welded / brazed to the absorbing surface and this constitutes an important advantage compared to the traditional technique both in terms of minimum distance between ducts. adjacent both in terms of heating speed of the heat-carrying fluid circulating inside them.

Between said tubular ducts 6 there are provided in the solar collector 2 further tubular cavities 8, possibly open longitudinally and intended to receive fixing screws to the header manifold-distributor profile 10, for the connection of the individual ducts 6 of the same or of different modules, in accordance with the chosen system configuration.

The extruded section forming the absorber module 2 is preferably of the open type, in the sense that it has both free edges, which are shaped so as to allow interlocking engagement with the corresponding edges of different components, which together constitute the solar thermal collector according to the invention.

Another component of the solar collector according to the invention is constituted by the so-called "insulation" module 12. It consists of an extruded profile in thermoplastic material or in aluminum, also preferably of the open type, with the free edges shaped so as to allow the interlocking engagement with the edges of other profiles, in particular with the edges of the absorber module 2.

It is envisaged that the insulation module 12 can be made in different heights depending on the climatic conditions existing in the place where the solar collector is to be installed, and it is also provided that inside said insulation module 12, that is in the cavity longitudinal bounded by this and by the absorber module 2, a preformed extruded insulation 16 and / or a polyurethane foam can be inserted, able to improve the thermal insulation of the absorber module 2 with respect to the underlying structure (see figs. 14 and 17) .

Another component of the solar collector according to the invention is constituted by a so-called "dissipator" module 18. It consists of an extruded profile in heat conducting material, preferably in copper or aluminum and has the function of dissipating the heat absorbed by the absorber module 2 possibly exceeding and for this purpose it comprises a plurality of parallel and preferably equidistant tubular ducts 20, each affected by a plurality of radiating fins 22. In these ducts 20 it can be made to flow, on the intervention of a management unit that controls a system of solenoid valves (not shown in the drawings), the excessively hot heat transfer fluid, due to its cooling.

The dissipator module 18 is also provided with tubular cavities 24 preferably open longitudinally, suitable for receiving fixing screws of header manifold-distributor elements, which can be distinguished from the manifolds-distributors 10 of the absorber module 2, or can be made monolithically with these by molding or die-casting or also with other methods of mechanical processing of metal blocks.

Similarly to the absorber module 2 and to the insulation module 12, also the dissipator module 18 is preferably of the open type, with the shaped edges for coupling to the insulation module 12, which for this purpose has complementary longitudinal cavities on the profile.

As stated above, the free edges of the three absorber modules 2, insulation 12 and heat sink 18 are designed for their mutual coupling engagement, although it is also possible that this coupling is made further reliable thanks to the use of junction 28, which preferably embrace the three modules already assembled together and thus also constitute lateral finishing profiles, which can be made in the most varied shapes, as long as they are suitable for coupling. These finishing profiles 28 can in turn be shaped in such a way as to highlight longitudinal cavities capable of containing thermally insulating material that avoids heat dispersion between the external solar collector and the environment with which it borders laterally (see fig. 5). A double-sided profile 30 is also provided (see fig. 4), which in addition to engaging the three modules of a solar thermal collector according to the invention, also engages an identical adjacent collector and in this way makes it possible to create a collector multiple solar panels, obtained by placing several single solar collectors side by side according to the invention.

Regardless of whether this profile 28 or 30 is single or double-sided, it can extend beyond the absorbing surface of the absorber module 2 and be provided with suitable grooves for engaging the longitudinal edges of a glass plate 32 (see fig. 2) able to delimit a closed space above the flat surface 4 of the absorber module 2 and thus to create a greenhouse effect, useful for better insulation towards the outside.

Depending on the requirements, the same finishing profile 28,30 can be installed in different positions, i.e. in the standard position, not protruding from the absorbing surface 4 of the absorber module 2 (see the right profile of fig. 2), or in a non-standard position projecting from said surface 4 (see the left profile of fig. 2) to support the glass plate 32 or a photovoltaic module 34 (see the left profile of fig. 5).

If a glass plate 32 is used, this can be advantageously treated to be made anti-reflective or in any case to increase the absorption of solar radiation; in any case it can delimit with the underlying surface 4 of the absorber module 2 a compartment, in which a vacuum is created, which prevents the dispersion of the absorbed heat outside.

As an alternative to the flat (or even convex) glass plate 32 made of glass or other transparent material and applied to the absorber module 2 made of aluminum or other material with high thermal conductivity, said plate is made monolithically with the module absorber 2 through a single process of extrusion of a transparent or semi-transparent material, for example plexiglass (see fig. 3).

It is also envisaged that the extrusion process may involve not only the absorber module 2, but also the insulation module 12 and possibly also the dissipator module 18, which in this case form a single monolithic structure with the absorber module 2.

If there is the presence of the glass plate or plexiglass 32, this will not be in contact with the upper surface of the absorber, but will form a cavity that increases the greenhouse effect (see fig. 2); if, on the other hand, there is the presence of a photovoltaic module 34, its lower surface may be in contact with the upper surface of the absorber module 2, so as to optimize the heat exchange (see Fig. 5).

Advantageously, the glass or Plexiglas plate 32 could have a polarized film in its internal surface which, under certain conditions, for example in the event of excessive temperature of the heat transfer fluid or of the surface of the absorber module, prevents solar radiation from passing through it. This can be achieved by darkening it (for example by means of an electrical impulse).

If the absorber module 2 is made of transparent or semitransparent material (see fig. 3) it can be provided that under its tubular ducts 6 there is a black or in any case dark surface suitable for further absorbing solar radiation, after these they passed through the ducts themselves and heated the fluid contained in them.

This black surface could belong to the insulation module 12, provided that it is suitable for receiving direct solar radiation, and therefore is resistant to UV rays. by a photovoltaic module 34, which in this way makes the solar collector according to the invention also suitable for the production of electrical as well as thermal energy. Moreover, this solution removes heat from the photovoltaic module and if this is made with monocrystalline or polycrystalline silicon technology, the electricity produced is increased, thanks to the lower temperature present on its surface.

The presence of the heat sink module 18 and of a management control unit allows total control of the temperature present in the photovoltaic module 34, without having to resort to other artifices, such as expansion vessels (also useful for discharging the pressure generated) or tanks, on to completely discharge the excessively hot fluid, which could also compromise or worsen the operation of the photovoltaic module 34.

The solar thermal collector according to the invention, which can be constituted by the absorber module 2 alone or by the absorber module 2 coupled with the insulation module 12 and / or with the dissipator module 18, can be hooked to an underlying support structure or, in advantageously, to a structure formed by modular elements, of the type described in the patent application PCT / IB2008 / 002813 of 22 October 2008 (see figs.

13 and 14).

Regardless, however, of the nature of the support structure and of the bonding methods of the solar collector according to the invention to it, thanks to the realization of said solar collector with only extruded modules, it is evidently possible that it is made in the desired length, following the cut to measure of the profiles themselves, which are then closed at the ends, as mentioned, with header manifolds-distributors 10, 26. This allows to obtain solar collectors of any length, also according to the specific needs of certain applications, up to a maximum determined by extrusion machines or by logistics: in any case, this length is considerably higher than that achievable with traditional solar collectors.

A header manifold-distributor 10 is described in detail below, to be applied to the ends of the absorber module 2 only, to establish suitable connections between the ducts 6 present therein, but it is clear that the description is similar in the case of a header manifold-distributor 26 to be applied simultaneously to the absorber module 2 and to the heat sink module 18, already coupled together.

Each header manifold-distributor 10 essentially comprises a base body 36 and a distribution cover 38, applicable to it, both made of die-cast aluminum or injected plastic. Should the base body 36 and the cover 38 be made of plastic material, the watertight seal between the two can be guaranteed by using ultrasonic welding or hot blade, thanks to the presence of appropriately positioned ribs 39. Alternatively, this function can be obtained with the aid of silicone or shaped gaskets, inserted in seats obtained in the base body and / or in the lid.

The base body 36 has a parallelepiped shape with dimensions related to the section of the absorber module 2. It comprises a plurality of parallel and equidistant sleeves 40, in a number and center distance equal to that of the ducts 6 of the absorber module 2, so that it can be coupled at the ends of these, with the interposition of an O-ring type gasket, housed in a suitable seat.

Between the sleeves 40 of the base body 36 there are cylindrical tubular appendages 42, having the cavities aligned with the cavities 8 of the absorber module 2 and suitable for the passage of fixing screws of the base body 36 to the absorber module 2.

Each sleeve 40 communicates with the upper surface of the base body 36 through a duct 44, which makes said sleeve accessible from said surface.

The other element that forms the distributor manifold 10 is constituted, as mentioned, by the cover 38. It has a flattened parallelepiped shape and is applicable to the surface of the base body 36, into which the ducts 44 open. in the cover 38 they engage in centering holes 45 obtained in the base body 36 and allow their correct mutual positioning.

A series of channels 48 for connecting the openings of said ducts 44 are formed in the cover 38, and these channels 48 are different from cover to cover and provided in the number and arrangement corresponding to the connection methods of the ducts 6 to each other and to the other end of the absorber module 2, so as to provide the particular circuit for the circulation of the heat-carrying fluid in a spiral or serpentine or in any case of the desired type. The lid 38 is also provided with ribs 39, suitable for performing ultrasonic welding, hot blade or similar, in order to ensure perfect watertight integrity between the various ducts 44 of the base body 36 and the channels 48 of the lid. 38.

Figures 11-13 show two different distribution covers 38 to be applied to the same base body 36. In particular, the cover of figure 11 is provided with channels 48 connecting the second with the third duct 6 and the fifth with the sixth, while the lid of figs. 12 and 13 is provided with channels 48 connecting the first with the sixth duct 6, the second with the fifth and third with the fourth.

Since it is also necessary to connect the ducts 6 of a module together with the ducts 6 of an adjacent module, side by side it is provided that at least two of the sleeves 40 of the base body 36 of one of the two distributor manifolds 10 are open in the longitudinal direction to allow precisely to apply external connection fittings between adjacent solar collectors. If, on the other hand, the required configuration must allow entry and exit at both longitudinal ends of the solar collector, the sleeves 40 are opened one on a manifold-distributor 10 and the other on the other according to the diagram shown in fig. 8, and one of the ducts 6 of the absorber module 2 will not be used (eg the one highlighted with a dashed line).

In the embodiment illustrated in Figure 15, the header distributor manifold 10 is obtained from a single parallelepiped aluminum block, in which closed longitudinal ducts 50 are obtained by mechanical milling / drilling, aligned with the ducts 6 of the absorber module 2 and similar to the sleeves. 40 of the previous embodiment. Furthermore, in the parallelepiped block there are also intermediate transverse ducts 52, extending said longitudinal ducts 50 up to a horizontal surface of the block, and therefore similar to the ducts 44 of the previous embodiment, and transverse terminal ducts 54 connecting two of said intermediate transverse ducts 52 with the outside.

It is evident that when the free end of the intermediate transverse ducts 52 and of the terminal transverse ducts 54, with the exception of those intended for connection with the similar ends of the terminal transverse ducts of the adjacent manifolds, are closed with a plug, the monolithic distributor manifold now described is functionally equivalent to the manifold 10 previously described, made in two parts.

In the case of a manifold-distributor obtained in two parts, the centering of the base body 36 with respect to the absorber module 2 is obtained thanks to the presence of three appendages 56 surrounding two of the six sleeves 40 of the distributor manifold 10 and embracing the two corresponding tubular ducts 6 of the absorber module 2. Naturally the same centering system can be used for the header manifold-distributor of the dissipator module 18.

In the case of a monolithic manifold-distributor, its centering with respect to the absorber module 2 and / or the dissipator module 18 is obtained with pins simultaneously engaging holes 58 obtained in the monolithic element and grooves 60 present in the absorber module 2 and / or in the heatsink module 18.

An advantageous alternative, which can be used with extruded profiles made of metallic material, provides that the absorber module 2 and the insulation module 12 and / or the heat sink module 18 are coupled together with the interposition of a heat-insulating joint 61, which constitutes a sort of "cut thermal ”, capable of preventing the heat absorbed by module 2 from reaching the insulation module 12 and / or the heat sink module 18. This is illustrated in fig. 18, in which both the thermal break between the two absorber modules 2 and heat sink 18 and the preformed extruded insulation 16 are visible.

In a different embodiment, illustrated in Figures 19 and 20, the single header manifold-distributor, provided at each end of the absorber module 2 and / or of the dissipator module 18, is replaced by a plurality of header elements 62, which connect between them two or more tubular ducts 6.

This solution obviously has limitations in the choice of the path to be made to the heat transfer fluid, but it is of a somewhat simpler and less cumbersome construction and can be used in all those cases, in which it is simply required to circulate the fluid from a duct to another adjacent duct.

As can be seen in the drawings, each head element 62 comprises a base 64, a cover 66, to be applied to the base 64, and an eventual aesthetic cover 68, to be applied to the cover 66.

The base 64 has a preferably but not necessarily parallelepiped shape and is affected by through holes 70, having a center distance equal to that of the tubular ducts 6, and by centering appendages, which ensure its correct positioning with respect to the absorber module 2 and / or to the module heatsink 18.

O-rings 71 can be positioned in correspondence with the holes 70 obtained in the base 64 to ensure the seal with the respective tubular ducts 6.

The cover 66 of the head element 62 has a shape similar to that of the base 64 and is coupled to this with the interposition between the two of an O-ring or a shaped perimeter gasket 72 or directly by ultrasonic welding or other similar technology. In all cases, the connection of the cover 66 and of the base 64 to the section forming the absorber module 2 is obtained with screws which engage in the tubular cavities 8 provided in the section forming the solar collector.

When the cover 66 is applied to the base 64, it delimits with this a volume connected to the tubular ducts 6, which lead to that head element 62; it has the function of creating the fluidic continuity between these, a continuity which can however be obtained by means of a duct 73 obtained on the lid 66 and having its ends facing the through holes 70 of the base 64, when the lid is applied thereto.

The head element 62 can also comprise an aesthetic cover 68 which can be snapped onto the cover 66.

In a different embodiment, illustrated in figures 21 - 23, the extruded profile, which forms the absorber module 2, has the section in the shape of a circular segment or in any case flattened, so as to be housed within a row of tiles 74, as described for example in the patent application PCT / IB2008 / 002813. Unlike, however, what is described in this prior patent application, in the present case it is a photovoltaic - solar thermal hybrid system, with the lower profile that can subtract heat from the photovoltaic module, to transfer it to the heat transfer fluid, and make it usable for example for home heating.

Within the same row of bent tiles, a differently shaped profile can also be inserted (see Figs. 24 - 25), which exploits the entire available space, including that which in the previous embodiment was destined for the photovoltaic module.

In this case too, head elements 62 of the type indicated above and of a shape suitable for that of the extruded section can be applied to the ends of the extruded section.

The same extruded profiles and the same head elements 62 can also be applied inside a multifunctional element in a photovoltaic system 75 integrated in a roof tiles, of the type described for example in the patent application PCT / IB2008 / 002813.

In any case, the shape of the extruded section can be studied according to its foreseen location; in particular it, in addition to having the section with a flattened shape, can have a section in the shape of an inverted isosceles triangle (see figs. 26 and 27), to be housed in a longitudinal channel delimited by two adjacent rows of tiles 76, also of traditional brick type, and in this case it can be provided with an extruded profile 78 in Plexiglas or other transparent or semitransparent material, which can be attached to the absorber module 2 and capable of generating a greenhouse effect, useful for improving the performance of the solar collector.

In a further embodiment variant, illustrated in fig. 28, the solar collector according to the invention consists of an extruded profile 2 with a circular section, housed within a tube 80 of transparent material, inside which a vacuum can be created. This is possible by interposing, for example, an O-ring 82 between the profile of the absorber module 2 and the transparent tube 80 and thus creating a vacuum-tight chamber between the two. Of course, even if this vacuum is not created, a greenhouse effect will still be obtained around the profile that forms the absorber module 2.

Thanks to a suitable configuration of the ducts 73 obtained in the cover 66 to connect the tubular ducts 6 two by two, the path of the heat transfer fluid along these is spiral, so that the heat accumulated gradually remains in the internal part of the profile, which forms the hottest part of the solar collector.

The present invention has been illustrated and described in a preferred embodiment thereof and in some specific embodiments, but it is understood that executive variations may in practice be applied to it, without however departing from the scope of protection of the present patent for industrial invention.

Claims (12)

R I V E N D I C A Z I O N I 1. Solar thermal collector characterized in that it comprises at least one absorber module (2), made of extruded material and showing a plurality of ducts (6) intended for the circulation of a heat-carrying fluid, and at least two head elements (62), applicable to the ends of said absorber module (2) for the selective connection of at least one of its ducts (6) with at least another duct of the same or of another module. 2. Solar thermal collector according to claim 1, characterized in that it also comprises an insulation module (12), consisting of an extruded profile which can be coupled to said absorber module (2). 3. Solar thermal collector according to one or more of the preceding claims, characterized in that it also comprises a heat sink module (18) consisting of an extruded section of heat conducting material which can be coupled to said insulation module (12) and showing a plurality of ducts (20) provided of radiating fins (22) and intended for the circulation of said heat-carrying fluid. 4. Solar thermal collector according to one or more of the preceding claims characterized in that said absorber module (2) and / or said insulation module (12) and / or said absorber module (18) are made of metallic material and are coupled together through a thermal break junction. 5. Solar thermal collector according to one or more of the preceding claims, characterized in that each head element (62) comprises a base (64) applicable to the end of said extruded section forming said absorber module (2) and affected by a pair of through holes (70) facing two tubular ducts (6) of the latter, and a cover (66) applicable to said base and creating a fluidic connection between said holes (70). 6. Solar thermal collector according to one or more of the preceding claims, characterized in that said cover (66) defines with said base (64) a closed space, into which said through holes (70) open. 7. Solar thermal collector according to one or more of the preceding claims, characterized in that said cover (66) is affected by a duct (73) whose ends face said through holes (70) when said cover (66) is applied to said base (64). 8. Solar thermal collector according to one or more of the preceding claims, characterized in that the extruded profile, which forms the absorber module (2), has a section in the shape of a circular segment and is housed in the longitudinal cavity existing in a row of bent tiles (74 ) having the upper convex wall made of transparent material. 9. Solar thermal collector according to one or more of the preceding claims, characterized in that a photovoltaic module is associated with the extruded profile forming the absorber module (2). 10. Solar thermal collector according to one or more of the preceding claims, characterized in that the extruded profile forming the absorber module (2) has a section in the shape of an inverted isosceles triangle and dimensions such as to be housed in the longitudinal channel delimited by two adjacent rows of tiles (74,76). 11. Solar thermal collector according to one or more of the preceding claims, characterized in that the extruded profile forming the absorber module (2) has a cover profile (78) made of transparent material applied above the base. 12. Solar thermal collector according to one or more of the preceding claims, characterized in that the extruded profile that forms the absorber module (2) has a circular section and is housed in a vacuum-tight way within a tubular element (80) made of material transparent.