WO2010100667A2

WO2010100667A2 - Heat exchange device in particular for solar collector

Info

Publication number: WO2010100667A2
Application number: PCT/IT2010/000084
Authority: WO
Inventors: Demetrio Leone
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-03-02
Filing date: 2010-02-26
Publication date: 2010-09-10
Anticipated expiration: 2011-09-02
Also published as: WO2010100667A3; ITMI20090300A1; WO2010100663A2; WO2010100663A3

Abstract

Comprised in a heat exchange device (1) are a substantially plate- like body (2) having an inner cavity (3) suitable to contain a fluid (50), and also having a first wall (6) and a second wall (7). The inner cavity (3) is mainly extended along a development plane (P) substantially parallel to the first (6) and second (7) wall. The body (2) of such device (1) further comprises, between the first (6) and the second wall (7), a plurality of connection portions (9, 10) such to define a plurality of paths for the fluid (50) between at least one inlet duct (4) and at least one outlet duct (5), within the inner cavity (3).

Description

DESCRIPTION HEAT EXCHANGE DEVICE IN PARTICULAR FOR SOLAR COLLECTOR

The present invention regards a heat exchange device, in particular for solar heat collector. The present invention also regards a solar heat collector and a method for manufacturing a solar heat collector.

Currently known are solar heat collectors suitable to use solar radiation for heating a liquid intended, directly or indirectly, for household or industrial use. Usually, such collectors are made up of "solar panels".

Such solar panels generally comprise a plurality of pipes made of conductive material, flowing within which is a liquid to be heated, or a heating liquid.

The pipes are exposed to solar radiation, for example on the roofs of buildings or the like, in such a manner to heat and transmit heat to the heating liquid.

Such pipes are also usually insulated against heat exchange by conduction and convection with the surrounding environment, in such a manner to exchange heat solely through radiation. Due to such solution, the pipes may reach higher temperatures with respect to the surrounding environment and produce liquid at relatively high temperatures, even during winter.

Such insulation may be obtained through a casing outside the pipes comprising, at the surface exposed to the sun, a transparent plane which allows radiation of the same pipes. Usually vacuum is obtained within the insulation casing with the aim of improving heat insulation.

The abovementioned prior art reveals some important drawbacks .

As a matter of fact, the solar collector devices of the known type have a lower thermal efficiency and they are capable of converting into fluid heating only a small percentage of the energy radiated by the sun on the device .

The same collector devices of the known type are also difficult to manufacture and generally costly.

The pipes must also be made of copper or other expensive material and they must have low tolerances. Furthermore, the insulation casing is expensive and attainment of the vacuum condition inside the same is complex.

Another disadvantage lies in the fact that the known collectors not are usually very heavy and hence expensive to install and transport.

In this context, the object of the present invention is that of providing a heat exchange device, and a solar heat collector based on such heat exchange device, improved with respect to the prior art described above and such to allow overcoming - at least partly - the drawbacks mentioned above with reference to the prior art.

At this purpose, an object of the present invention is that of providing a heat exchange device in particular for a solar heat collector with high efficiency and, simultaneously, simple to manufacture and inexpensive.

Another object of the invention is to provide a solar heat collector which, in its entirety, is inexpensive, and/or has a high efficiency-to-cost ratio.

Still another object of the invention is that of providing a solar heat collector that is simple to manufacture and very light.

The abovementioned objects are achieved by means of a heat exchange device according to claim 1.

Further embodiments of such heat exchange device are defined by the dependent claims 2-14.

A solar collector comprising such heat exchange device is defined by claim 15.

Further embodiments of such solar collector are defined by the dependent claims 16-28.

A method for manufacturing such solar collector is defined by claim 29.

Further examples of methods for manufacturing the solar collector according to the present invention are defined by claims 30-35.

Further characteristics and advantages of the invention shall be clear from the description outlined hereinafter regarding preferred embodiments, provided solely for indicative and non-limiting purposes, with reference to the attached figures, wherein:

Fig. 1 illustrates a perspective view - from the bottom - of a heat exchange device according to an example of the invention;

Fig. 2 illustrates an exploded view of the heat exchange device of Fig. 1;

Fig. 3 illustrates a view of a detail of the lower wall of the heat exchange device of Fig. 1;

- Fig. 4 illustrates a partial sectional view of the heat exchange device of Fig. 1, along a sectional plane, indicated in Fig. 3 as I-I;

Fig. 5 illustrates a partial sectional view of a heat exchange device according to a further embodiment;

Figures 6A-6F illustrate geometric configurations of bulges on the lower walls of heat exchange devices according to further examples of the invention;

Figures 7A-7B illustrate, respectively, a top perspective view of the upper wall and a perspective view

- from the bottom - of the lower wall of a heat exchange device according to a further example of the invention; Figures 8A-8B and 9A-9B illustrate examples of bending of perimeter portions of the walls comprised in heat exchange devices according to the invention;

Fig. 10 illustrates a connection sleeve of an outlet or inlet duct for the heat-conductive fluid, a heat exchange device according to an example of the invention is provided with;

Fig. 11 illustrates a system for fixing to an external mounting or installation system, wherein a heat exchange device according to an example of the invention is provided with such fixing system;

Fig. 12 shows a top view of a solar heat collector according to an example of the invention;

Fig. 13 illustrates a transverse section of the collector of Fig. 12 and two particular enlargements;

Fig. 14 shows an exploded view of a solar heat collector according to a further example of the invention;

Fig. 15 illustrates a sectional view of a detail of the solar heat collector according to a further example of the invention;

Fig. 16 shows an exploded view of a solar heat collector according to a further example of the invention;

Fig. 17 illustrates a sectional view of a detail of a solar heat collector according to a further example of the invention;

Fig. 18 shows an exploded view of a solar heat collector according to a further example of the invention;

Fig. 19 shows a partial perspective view and a detail of a solar heat collector according to a further example of the invention;

Fig. 20 illustrates a perspective view - from the bottom - and two details of the solar heat collector of Fig. 19;

Figures 21A-21B show, in a partially sectioned perspective view, two details of the collector of Fig. 20;

Fig. 22 illustrates a perspective view of an assembled solar heat collector, according to an example of the invention.

With reference to figures 1 - 4, in the following it is described a heat exchange device 1 according to an example of the invention. Some details, and some respective variant embodiments, are illustrated in figures 5-6 and 8-11.

The heat exchange device 1 is suitable to heat a fluid, in particular a heat-conductive fluid 50 (visible for example in fig. 4), for example water, directly intended for use or for heat exchange with another fluid.

The heat exchange device 1 comprises a body 2 (indicated in fig. 1), substantially plate-like, having an inner cavity 3 (observable in particular in figures 4 and 5), also definable as an inner volume suitable to receive, contain and convey a heat- conductive fluid.

The heat exchange device 1 also comprises an inlet duct 4 and an outlet duct 5, arranged to respectively allow the inflow and outflow of the heat- conductive fluid into and from the cavity.

The inlet duct 4 is connectable to an inlet pipe, flowing through which is the heat- conductive fluid intended to get into the inner cavity 3, while the outlet duct 5 is connectable to an outlet pipe, flowing through which is the heat-conductive fluid after flowing out from the inner cavity 3. For such purpose, the ducts 4 and 5 preferably comprise threaded couplings whose dimensions are comprised between a quarter an inch and two inches, or other types of couplings.

Furthermore, the heat exchange device 1 comprises a first wall (for example a first wall 6 indicated in fig. 1, or a first sheet 6 in the exploded view of fig. 2) and a second wall (for example, a second wall 7 indicated in fig. 1, or a second sheet 7 in the exploded view of fig. 2), facing each other. Such first 6 and second wall 7, as illustrated hereinafter, are mutually connected by means of a plurality of connection portions.

It should be observed that, according to an embodiment of the present invention, the body 2 is obtained by means of a first and a second sheet manufactured separately and connected subsequently. According to a further embodiment, instead, the first and the second wall are obtained starting from a body made in a single piece.

Advantageously, the body 2 and the respective inner cavity 3 are extended mainly along a development plane substantially parallel to at least one, or preferably to both (as illustrated for example in fig. 1) , the walls 6 and 7.

Furthermore, advantageously, the inlet duct 4 and the outlet duct 5 develop in a direction substantially perpendicular to that of the development plane of the cavity, as illustrated in particular in figures 1 and 10.

Now, referring in particular to figure 2, it should be observed that the heat exchange device 1 comprises a first sheet 6 and a second sheet 7, which is provided with the inlet duct 4 and the outlet duct 5.

The first 6 and the second 7 sheet substantially extend along a plane.

According to an embodiment, the first 6 and the second 7 sheet are substantially rectangular-shaped.

Such first 6 and second 7 sheet have surfaces of the order of size of m², preferably between 0.5 and the 5 m², and perimeters of the order of size of metres, preferably between 3 and 12 m.

Advantageously, the first sheet 6 and second sheet 7 are made of metal material, even of the inexpensive type, in particular steel, or alternatively, aluminium or copper.

According to an alternative embodiment, the first 6 and second 7 sheet are made of synthetic material having a suitably high thermal conductivity.

The first 6 and the second 7 sheet are mutually connected by means of a plurality of connection portions (indicated for example in Fig. 1 with the reference numbers 9 and 10), in such a manner to define the inner cavity 3 (illustrated for example in Figures 4 and 5) of the heat exchange device 1, suitable to receive, hold and convey a heat-conductive fluid.

The inner cavity 3 is substantially determined by two surfaces facing each other, thus definable inner surfaces, of the first sheet 6 and of the second sheet 7, respectively. In such manner, the inner cavity is mainly extended along a development plane parallel to the development plane of the two sheets 6 and 7. The first sheet 6 is arranged to form the upper part of the body of the heat exchange device 1; hence, the outer surface of the first sheet 6, i.e. the one opposite to the abovementioned inner surface of the same first sheet 6, is suitable to be exposed to solar radiation and collect the heat thereof.

The second sheet 7 is arranged to form the lower part of the body of the heat exchange device 1.

It should be observed that shown in the exploded view of fig. 2 are the outer surfaces of the second sheet 7, i.e. the lower outer surface of the body 2, and the inner surface of the first sheet 6.

Now, referring to the plurality of connection portions between the first sheet 6 and the second sheet 7, it comprises a first connection portion 9 (indicated in fig. 1 and whose details are further illustrated in Figures 8A-8B and 9A-9B) and second connection portions 10 (illustrated in particular in figures 1 - 7) .

The first connection portion 9 is extended along the perimetrical edge of the first sheet 6 and of the second sheet 7.

It should be observed that the first connection portion 9 is suitable to ensure that the first 6 and the second 7 sheet, once assembled to each other, define the inner cavity 3, suitable to hold the heat- conductive fluid, of the body 2 of the heat exchange device 1, in such a manner that such body 2 is fluid-tight.

Such first connection portion 9 is thus obtainable in such a manner to guarantee the abovementioned property considering different conditions of work, for example in case of pressure and temperature levels of the fluid such as the ones which take place under normal operating conditions of the heat exchange device 1.

According to an embodiment, the first connection portion 9 comprises a sealing profile along the entire perimetrical edge of the first 6 and second 7 sheet.

Such sealing profile is obtained, for example, by means of an outer perimeter welding seam between the first 6 and the second 7 sheet.

Referring to Fig. 8A, it should be observed that the sealing profile 9 is obtained, for example, by means of a shaping and a mutual welding of the first 6 and of the second sheet 7. In the illustrated example, the shaping of the upper sheet 6 consists in a 90° downward bending of a peripheral perimeter portion of the sheet 6; while the shaping of the lower sheet 7 consists in a 90° upward bending of a peripheral perimeter portion of the sheet 7.

According to a further embodiment, described in fig. 8B, the sealing profile 9 is obtained by means of a shaping and a mutual joint, for example by means of welding or melting with laser or other techniques, of the first 6 and of the second sheet 7. In such case, the type of 90° bending of the sheets is such that the bent portions are adjacent to each other along the entire height of the sealing perimeter profile, and the bent portion of one of the two sheets is arranged inwards with respect to the cavity 3, and internally with respect to the bent portion of the other sheet.

According to another embodiment, illustrated in fig. 9A, the shaping of the upper sheet 6 consists in a 90° downward bending and in a further outward bending of a perimeter peripheral portion of the sheet 6; while the shaping of the lower sheet 7 consists in a 90° upward bending and in a further outward bending of a peripheral portion of a perimeter peripheral portion of the sheet 7. In such example, the outermost portions of the sheet 6 and of the sheet 7 are mutually joined, for example by means of welding, in a plane parallel to the development plane of the sheets themselves.

According to another embodiment, shown in figure fig. 9B, the sealing profile 9 is suitably obtained from a shaping and from a mutual joining or welding of the sheets, in a configuration wherein the lower sheet 7 comprises a perimeter portion bent upwards. Also shown in fig. 9B is a part of the cavity 3 comprised between the sheets 6 and 7; such cavity is obviously present, though not explicit, even in the embodiments described in figures 8A, 8B, 9A.

According to different embodiments, other different bending geometries and other methods for joining the first and the second sheet may be used.

Particularly referring to figures 1, 2, 6, 7, it should be observed that the inlet 4 and outlet 5 ducts are preferably connected to the lower sheet 7 at positions near the sealing profile and arranged along a central longitudinal axis of the second sheet 7.

According to further embodiments, the inlet 4 and outlet 5 ducts are arranged in other positions along the perimeter of the body of the heat exchange device 1.

According to a further embodiment, the inlet duct comprises a plurality of openings, arranged along a side of the rectangular perimeter, suitable to further facilitate the distribution of the heat- conductive fluid along the entire inner cavity.

According to further embodiments, not illustrated, the heat exchange device has two or more inlet ducts, suitably connected to two or more respective inlet pipes, to allow the heat- conductive fluid to flow into the inner cavity of the heat exchange device. Furthermore, according to further embodiments, not illustrated, the heat exchange device has two or more outlet ducts, suitably connected to two or more respective outlet pipes, to allow the heat- conductive fluid to flow out from the inner cavity of the heat exchange device.

It should be observed that the inlet duct 4 and the outlet duct 5 are preferably circular-shaped, as illustrated in the examples of the figures.

According to further embodiments, not illustrated, the heat exchange device has inlet ducts and outlet ducts whose shape is different from the circular one, for example elongated, ellipsoidal, polygonal and so on and so forth.

Now attention shall be focused, with particular reference to figures 1-4 and 6-7, on the second connection portions 10, which are arranged in the inner cavity 3 of the heat exchange device 1.

In particular, the second connection portions 10 are preferably distributed, in the illustrated examples, on the second sheet 7.

From a structural point of view, the plurality of second connection portions that the second sheet 7 is provided with comprises bulges 10, i.e. portions projecting with respect to a base plane corresponding to the surface of the sheet itself towards the inner cavity 3 of the body of the heat exchange device, as illustrated, in particular, in the view of Fig. 4 (with reference to the sectional plane I-I indicated in fig. 3) .

In particular, the bulges 10 are preferably raised with respect to the base plane of the second sheet 7 in such a manner that they are extended upwards towards the first sheet 6.

Regarding this, it should be observed that the bulges 10 shall be deemed "hollow", i.e. "concave", in the view of the figures showing an outer surface of the sheet 7 (for example the figures 1, 2 and 7) .

From a morphological point of view, the bulges 10, sectioned by a plane parallel to the second sheet 7, are preferably circular and occupy a surface comprised between 10% and 50%, more preferably between 20% and 25% of the total surface of the same second sheet 7. They are arranged according to a preferred geometry having a regular triangular basic pattern, as illustrated in figure 3.

The bulges 10 preferably have a diameter of the order of size of centimetres, and more preferably comprised between 1 cm and 5 cm, and height of the order of size of millimetres, preferably comprised between 1 mm and 10 mm .

In another embodiment, shown in fig. 5, the second connection portions 10 are distributed, preferably, both on the first sheet β and on the second sheet 7. In such case, they are raised from both base planes of the first 6 and second 7 sheet in .such a manner that the bulges of the first sheet 6 are extended towards the second sheet 7 and the bulges of the second sheet 7 are extended towards the first sheet 6. It should be observed that, in such case, the bulges 10 of the first 6 and of the second 7 sheet are preferably aligned in directions perpendicular to the respective base planes.

In another embodiment, not shown in the figures, the second connection portions 10 are distributed on the first sheet 6. In such case, they are preferably raised with respect to a base plane of the first sheet 6 in such a manner to extend downwards and towards the second sheet 7.

Regarding the obtainment of the bulges, it should be observed that such bulges 10 may be formed through operations of the known type such as moulding, lamination, bossing, pressure die casting or hydroforming .

Regarding the attainment of the second connection portions, it should be observed that the second connection portions 10 are obtained at the bulges by means of, for example, spot welding.

It should be observed that the second connection portions 10 cooperate with the first connection portion 9, with the aim of guaranteeing connection between the sheets 6 and 7.

By suitably arranging the bulges 10 on the inner surface of one or both sheets 6 and 7, suitable distance between the sheets themselves may be obtained, preferably between 1 and 50 mm and more preferably between 1 and 10 mm.

It should be observed that, advantageously, the bulges 10 considerably expand the surface of the device suitable to perform the heat exchange function.

It should also be observed that the plurality of second connection portions 10 and the first connection portion 9 define a plurality of paths for the heat- conductive fluid between the at least one inlet duct and the at least one outlet duct, in the inner cavity of the heat exchange device.

In particular, the second connection portions 10 between the sheets 6 and 7 perform the further important function of having an influence on the type of flow that characterizes the flowing of the heat-conductive fluid. Such second connection portions 10 are capable of continuously deflecting the flow of the heat-conductive fluid, thus obtaining two effects: a slowing down, on the whole, of the flow itself, suitable to increase the transfer of energy from the body of the heat exchange device 1 to the heat-conductive fluid, and a homogenization of the fluid distribution within the cavity 3.

As a matter of fact it should be observed that, by choosing different sectional planes perpendicular to the sheets 6 and 7, the section of the cavity 3 is variable. For example, in the section along plane II-II of Fig. 3 the fluid is not hindered and tends to be distributed uniformly. On the contrary, in other sections, for example in the section along plane I-I of Fig. 3 (illustrated in detail in fig. 4) the fluid is deflected by the bulges 10 which project into the cavity 3 and shape it in a particular manner.

Thus, in such way, the second connection portions 10 (i.e. bulges 10, in the illustrated examples) represent a simple and efficient manner of imposing a "sinuous" path to the heat-conductive fluid, without having to provide complex tortuous or coiled piping.

In addition, further embodiments of a heat exchange device 1 according to the present invention provide for different inner shapes of the cavity 3, defined by bulges of different shapes, with respect to those illustrated up to now, such as those indicated for exemplifying purposes in figures 6A - 6F.

As shown in such figures, the possible different shapes regard the particular pattern of the bulges, which is designed by operating on different parameters, such as the dimension and the sectional shape of the single bulges, the spacing and the geometric arrangement of the bulges. Regarding the sectional shape of the single bulges, alongside the circular shape shown in figures 6A- 6F, other forms may be provided, for example be rhomboidal, knurled, rectangular shapes and so on.

Advantageously, the design of the "pattern" of the bulges is conceived with the aim of optimising the abovementioned function of influencing the type of flow that characterizes the flowing of the heat-conductive fluid.

According to another embodiment of the heat exchange device 1, not illustrated, the body 2 comprises only one sheet suitably bent on itself along an axis defined on the same sheet, to form an upper portion and a lower portion that are entirely analogous, respectively, to the first and to the second sheet described previously. The plurality of connection portions (bulges) may be distributed on one or both portions of the bent sheet .

According to an embodiment , illustrated for example in fig. 7, the heat exchange device 1 is obtained by means of two metal sheets manufactured separately, for example through lamination, and subsequently connected, for example by means of welding, or laser welding, or riveting, or any other technology.

Referring to figure Fig. 10, it should be observed that heat exchange device is preferably provided with a connection sleeve 51 on its inlet duct, or on its outlet duct, or on both in such a manner to facilitate the connection with an external system for the supply and conveyance of the heat-conductive fluid. Each of such sleeves may be welded or connected by means of other technical solutions, per se known, on the lower sheet.

Referring to Fig. 11, it should be observed that, according to further embodiments, the heat exchange device, on its upper sheet, or on its lower sheet, or on both, may be provided with elements 52 for fixing to an external mounting or installation system. Each of such elements may comprise a special threading for screws suitable for fixing, for example, on a mounting bracket intended to be arranged on the installation site (for example, roof) .

According to a further embodiment, the heat exchange device comprises a profile 53 (shown for example in fig. 9B) extending from one of the its first and second wall, in such a manner that such profile defines an accommodation suitable to receive or accommodate an edge for an upper cover portion.

It should also be observed that the heat exchange device is preferably painted black or dark to increase the energy absorption capacity.

Now, it should be observed with particular attention that, according to a further example of the invention already mentioned beforehand (with reference to figure Fig. 1 for illustration thereof), the heat exchange device 1 has a body made in a single piece, for example by means of blowing or rotational moulding or thermoforming or injection of synthetic material into one or more suitable moulds, such methods being per se known.

Such body has a lower wall 7 and an upper wall 6. Furthermore, in such embodiment, the first connection portion 9 between the lower 7 and upper 6 walls, along the entire perimetrical edge, is obtained due to the fact that the body of the heat exchange device 1 is made in a single piece.

Additionally, the heat exchange device according to such embodiment has an inner cavity, defined by the first wall 6, by the second wall 7, by the first connection portion 9 and by second connection portions 10 (for example, bulges 10) morphologically and functionally entirely analogous to the bulges 10 previously described with reference to other embodiments. In the embodiment described herein, such bulges 10 are obtained when manufacturing the body made in a single piece.

It should be observed that, in such embodiment, even the inlet 4 and outlet 5 ducts are manufactured integrally with the abovementioned single piece, and they are shaped in such a manner to allow direct shape- coupling thereof with respective inlet and outlet pipes of an external system for the supply and conveyance of the heat-conductive fluid.

Alternatively, suitable connection sleeves with the inlet and outlet pipes may be made and joined to the inlet and outlet ducts, during the manufacturing step, for example when moulding.

It should be observed that for the other aspects, not explicitly mentioned herein, the heat exchange device having a body made in a single piece is analogous to the heat exchange devices formed by two sheets manufactured separately and joined subsequently, according to the embodiments described previously.

According to another embodiment, the heat exchange device is obtained made of synthetic material starting from two distinct walls, joined together by means of hot melting, ultrasonic or other welding or adhesion techniques .

In each of the embodiments described above, it is possible to implement a further solution with the aim of further increasing the overall energy generation capacity of the heat exchange device. Such solution, per se known in various forms, consists in applying a photovoltaic or electrochemical coating, capable of transforming the solar energy into electrical energy, on a wall of the device. Advantageously, such coating is applied on the upper surface of the upper wall of the heat exchange device, or beneath a cover transparent to light placed at contact or at a short distance from the upper surface.

Such coating may for example be, a nanocrystalline coating made up of a layer composed of millions of minute nanometric-size grains. When the ray of light is tapped by such coating, electrons are freed through the granular layer, they accumulate in the outer part of the coating and they are then conveyed into an external circuit, generating a current flow.

In such manner, the heat exchange device becomes a "hybrid" device, capable of generating, starting from the source represented by solar energy, both heat and electrical energy. Referring to figures 12-14, following is a description of the example of a solar heat collector (or, more simply, solar collector) 100, comprising a heat exchange device according to any one of the embodiments described above.

The solar heat collector 100 preferably comprises an insulation casing 101, suitable to insulate the heat exchange device 1 from heat exchange by conduction and from convection with the surrounding environment.

Advantageously, the insulation casing 101 comprises a lower portion 102 for accommodating the heat exchange device, such portion 102 surrounding the lower part of the device 1 and extending mainly along a plane (indicated as P in fig. 13) parallel to the development plane of the cavity of said device. Such lower portion 102 is configured in such a manner to support the device 1 and it is also suitable to be constrained to a wall made of cement, to a roof or to other bearing structures of the collector. Advantageously, this allows considerable versatility regarding installation, further facilitated by the considerable lightness of the collector 100.

The lower portion 102 is made of heat insulating synthetic material (or more simply insulating material) , for example foamed polymer material, preferably polyisocyanate, and whose height is of the order of size of centimetres .

The lower portion 102 comprises a seat 106 (fig. 14) suitable to receive - with geometric coupling - at least one portion of the body of the heat exchange device. Preferably, such seat is placed at contact with the lower wall 7 of the device 1 and it is extended over the entire length of the same.

Obtained on such portion are two through holes (or more simply holes, or openings) 107, 108, suitable to be geometrically coupled, respectively, to the inlet duct 4 and to the outlet duct 5 of the heat exchange device 1, so that such inlet and outlet ducts may be connected with the respective inlet and outlet pipes 114, 115 (fig. 13), towards an external system for the supply and conveyance of the heat-conductive fluid.

The holes 107, 108 are preferably circular-shaped. According to other embodiments, not shown, the holes have different shapes with respect to the circular one, for example elongated, ellipsoidal, polygonal, in such a manner to be adapted in each case to the respective inlet and outlet ducts of the respective heat exchange device.

According to other embodiments, not shown, the lower portion 102 comprises a plurality of holes, a number sufficient to be suitably coupled to a plurality of inlet and outlet ducts the heat exchange device, intended to be accommodated in the collector, may be provided with.

The lower portion 102 further comprises a side frame 103, which is extended along the entire perimeter comprising the sealing profile of the device 1.

In the embodiment described herein, the side frame 103 is manufactured using synthetic insulating material, integrally with respect to the lower portion 102.

According to an embodiment, the lower accommodation portion 102 is manufactured by means of known procedures, such as for example rotational moulding, bi-injection, thermoforming twin sheet.

The insulation casing 101 also comprises a transparent cover portion 104, over the surface - exposed to the sun - of the heat exchange device 1, hence over the upper sheet 6.

The transparent cover portion 104 is preferably made up of a transparent panel made of polymer material, more preferably polycarbonate, arranged parallel to the plane P. The transparent portion 104 may also be made of prismatic glass, or patterned glass, or single or double- sheet sheet polycarbonate having a cavity in-between, in such a way to increase the insulation of the heat exchange device 1 from the surrounding environment. The transparent cover portion 104 is mounted, for example by adhesion, onto the lower portion 102. Preferably, to facilitate mounting, an edge of such cover portion is inserted into a special accommodation obtained in an upper profile 153 (observable for example in fig. 19) , extended from the side frame 103 of the lower portion 102. Alternatively, an edge of the cover portion 104 may be inserted into a special accommodation obtained on the previously mentioned profile 53 (see figure fig. 13) that the heat exchange device 1 may be provided with.

Furthermore, vacuum may be attained in the casing 101, in order to further improve the insulation.

Figure 13 shows - in detail - a complete section and two details of the embodiment described above of a solar collector 100 according to the invention.

In such figure, it may also be observed that the polymer material - that the lower portion 102 is made of - comprising the side frame 103, per se serves as means for heat insulation of the lower portion. In other words, the lower portion 102 serves both accommodation and heat insulation purposes.

Regarding the fixing of the solar collector 100 at a desired position, the insulation casing 101 is provided with elements 152 (illustrated in fig. 17 and in fig. 21) for fixing to a system for mounting or installing the collector, for example, a bracket for mounting onto a roof. Such fixing elements 152 may be integrated in the lower accommodation portion 102: preferably, four fixing elements are provided for at the four corners of the frame 103 of the lower portion 102, as shown in figure 21. Advantageously, such fixing elements 152 are elements comprising threaded inserts for screws.

Alternatively, should the heat exchange device be made of metal, the fixing elements 52 may be provided on the heat exchange device itself, as illustrated above when describing figure 11.

Figure 14 shows an exploded view of another embodiment of the solar collector 100, having characteristics similar to the one described above. Special focus to the lower portion 102, comprising the seat 106 suitable to receive at least one part of the body of the device 1, the heat exchange device 1, the transparent cover 104, the openings 107, 108 for the inlet and outlet ducts. In the illustrated example, the seat 106 has a surface and height substantially equivalent or slightly exceeding the surface and thickness of the heat exchange device and it is thus arranged to accommodate the entire body.

According to a further embodiment of the collector, illustrated in figures 15 and 16, the insulation casing 101 provides for further heat insulation means 105 interposed between the lower portion 102 and the device 1. Such means may be for example the insulation material 105 injected between the portion 102 and the device 1 after assembling such elements. Fig. 15 shows a particular detail, while fig. 16 illustrates an exploded view of the solar collector according to such embodiment, where the exploded view shows the components of the solar collector after it has been entirely formed, and not the components before assembly. Regarding this, special focus on the configuration of the insulation material 105, deposited on the lower portion 102, whose shape is complementary to the shape of the lower surface (not shown in this figure) of the body of the device 1, and thus consists of "projecting" bulges in positions corresponding to the concave bulges of the lower surface of the device 1.

According to a further embodiment of the collector, illustrated in Fig. 17 by means of the sectional view of a detail, the lower portion 102 comprises a hollow volume 125 therein, injected into which is the insulating synthetic material 105 which serves as exclusive or additional means of heat insulation for the lower portion.

According to a further embodiment of the collector, illustrated in fig. 18, the solar collector 200 comprises a side frame 203, as an element for supporting the heat exchange device, a heat exchange device 1, a transparent cover portion 204 and insulation means 205, which are injected into suitable moulds during the step of assembling the collector in such a manner to serve both the function of heat insulation and accommodation of the heat device .

The frame 203 is preferably made of aluminium. According to alternative embodiments, the frame 203 is made using other metal or synthetic material.

According to a further embodiment of the collector 200, illustrated in Figures 19 and 20, the heat exchange device 1 and the frame 203 are manufactured made of synthetic material in a single piece, by means of known methods, such as for example rotational moulding, bi- injection, thermoforming twin sheet. In such case, both the device and the frame are preferably painted black. The insulation means 205 are obtained by injection into suitable moulds in the step of assembling the collector, in such a manner to perform the functions of both heat insulation and accommodation of the heat device.

Referring to Fig. 20, special focus also to the inlet 4 and outlet 5 ducts, as well as the fixing elements 152, that are incorporated in the collector 200. According to a further embodiment of the collector, not illustrated, the heat exchange device and the entire lower accommodation portion are manufactured made of synthetic material in a single piece, by means of known methods, such as for example rotational moulding, bi- injection, thermoforming twin sheet. In such case, void (i.e., free) spaces between the heat exchange device and the lower portion are provided, intended to be filled with heat insulation material, for example by means of injection.

A perspective view of a solar collector of such type, once entirely assembled, is indicated in figure 22.

Illustrated in such figure is a further detail, specific of the further embodiment described hereinafter. With the aim of increasing the overall energy generation capacity of the collector, it is possible to adopt solutions consisting in applying - on a lower part of the transparent cover portion 104 - an electrochemical coating 199 capable of transforming the solar energy into electrical energy. Such coating 199 may for example be a nanocrystalline coating made up of a layer made up of millions of minute nanometric-size grains. When a ray of light is tapped by such coating, electrons are freed and pass through the granular layer thereof, they accumulate in the outer part of the coating and they are subsequently conveyed into an external circuit, thus generating a current flow.

Such electrochemical coating 199, being in turn transparent, allows maintaining the insulating capacity of the insulation "casing, and simultaneously, serves as an electrical energy generator. In such manner, the solar collector becomes a "hybrid" device capable of generating, starting from the source represented by solar energy, both the heat energy and electrical energy.

The solar heat collector 100, 200 according to any one of the embodiments, above outlined from the structural viewpoint, operates as follows.

The solar collector 100, 200 is arranged on the roof of a building or on any other part of the building (for example, a perimeter wall) . Preferably the same solar collector 100, 200 is arranged at an inclined position in such a manner to allow the flow of the liquid or fluid 50 (for example, due to gravity, even without requiring overpressure) .

The inlet duct 4 is connected to the inlet pipe 114, and the outlet duct 5 is connected to the outlet pipe 115.

The fluid 50 flows through the heat exchange device 1 and is heated by the solar radiation.

In particular, the heat-conductive fluid 50 enters the heat exchange device 1 through the inlet duct 4. Such fluid 50 thus flows in the inner cavity of the heat exchange device according to the gravitational gradient and reaches the outlet duct 5. During the flowing in the inner volume (i.e. in the cavity 3) of the heat exchange body, the fluid 50 is continuously deflected by the bulges 10, in such a manner to create turbulences which "slow down" the transit through the heat exchange body, and thus substantially passes through the entire development plane P of the cavity 3.

During the transit time, the heat-conductive fluid acquires heat from the sheets, in turn heated, in particular, by the solar radiation. It should be observed that the bulges expand the surface of the sheets and thus achieve a high heat exchange even in the presence of relatively small overall dimensions of the system.

Regarding solar radiation, it should be observed that the solar rays particularly heat the first sheet ^β, which is preferably painted black to better keep the solar radiations. The first sheet 6 in turn heats the second sheet 7 by contact along the connection portions 10 (bulges) .

The two walls 6,7 are not exposed to the conduction of the heat of the air, which usually has a lower temperature, thanks to the presence of the insulation casing 101.

It should be observed that, in the context of this description, the term "solar energy" is used to indicate energy obtainable directly or indirectly from the environment, heated by the sun. As a matter of fact, the collector is capable of collecting, alongside direct solar energy, also environmental energy related for example to rain, snow, fog, wind, as long as the system, in its entirety, comprises a suitable heat pump and a suitable heat exchanger.

Following is the description of a method for making solar heat collectors, according to an example of the invention.

Such method comprises an innovative step which consists in inserting a heat exchange device 1, according to the present invention, into a mould substantially counter-shaped to the lower portion 102, and injecting - into said mould - heat-insulating synthetic material 105, 205, for example foamed polymer material, preferably polyisocyanate, in such a manner to obtain the same lower portion. Such lower portion is thus such to surround the lower part of the device, mainly extending along a plane parallel to the development plane of the device itself.

According to a further example, the method further comprises a step of inserting - into the mould, in addition to the heat exchange device - a side frame 203 having dimensions and position such to surround the perimeter of the heat exchange device 1, leaving a perimetrical space along said perimeter. The method then comprises a step of injecting - into the mould - the heat insulating synthetic material 205 in such a manner to fill said perimeter space.

According to another embodiment, a method for obtaining the solar heat collectors 100, 200 comprises a step for manufacturing - by moulding - a heat exchange device 1, according to any one of the respective embodiments described above, and a lower portion 102 for accommodating an insulation casing 101 for such device, according to any one of the respective embodiments described above in such a manner that there is free space for the heat insulation, suitable to accommodate heat insulation material, around at least one part of said device; and a subsequent step of injecting the heat insulation material 105, 205 into said free space of the heat insulation.

According to a further example, the free space for the heat insulation is a hollow volume 125 obtained inside said lower portion 102, and the heat insulation material 105 is injected into such hollow volume.

According to a further example, the heat exchange device and the lower portion of the insulation casing are made - by moulding - in a single piece starting from the synthetic material by means of a process of rotational moulding, or bi-injection, or thermoforming twin sheet.

According to an alternative example, the solar collector is manufactured by means of the assembly of a heat exchange device and a lower portion, after such device and such lower portion of the insulation casing were manufactured separately, by means of two .independent formation processes, each of which may be rotational moulding or bi-injection, or thermoforming twin sheet.

Lastly, each of the examples illustrated above may provide for the step of inserting an upper transparent portion 104, 204, as an upper cover of the assembly made up of the heat exchange device and the lower portion.

The invention allows important advantages .

With particular reference to the heat exchange device, it should be observed that it is highly efficient .

This is obtained due to various factors: the considerable development of the inner cavity of such device along the plane P; the high heat conductivity of the bulges 10, that determine, according to experiments of the applicant, an ideal efficiency of the heat exchange device 1; the particular type of flow the heat- conductive fluid, which is "slowed down" and continuously "deflected" by the bulges.

On the other hand, the heat exchange device according to the invention is inexpensive, easy to manufacture and light. The solutions described above based on the bulges 10 represent a simple and efficient method for imposing a plurality of possible sinuous paths for the heat-transmitting fluid, without requiring long "coils" or serpentine-like pipes. Such solutions may also be easily optimized, depending on the desired performance, by operating on the numerous "free" variables of the design, such as the size, distance, shape, distribution pattern of the bulges themselves.

Furthermore, the heat exchange device according to the invention may be obtained using inexpensive materials, i.e., it may be made of metal or synthetic material, depending on the intended type of use, for example, temperature ranges within which it is probably intended to operate.

The various proposed methods of manufacture, according to different aspects, are convenient: on one hand, methods based on simple operations such as lamination and welding; on the other hand, alternatively, methods based on moulding processes, which are per se more complex but have the considerable advantage of fabricating the entire device in a single piece and in a single step.

Referring to the solar collector in its entirety, it should be observed that, following what outlined beforehand, it is in turn highly efficient.

Furthermore, the various examples described, regarding the method for manufacturing the solar collector, are convenient according to different aspects: on one hand, methods based on easy assembly of the device and the insulation casing, manufactured separately in an easy and optimized manner; on the other hand, alternatively, methods based on processes for moulding the casing around the device; on the other hand again, methods based on manufacturing the device and part of the insulation casing in a single piece.

In summary, due to the reasons outlined above and due to the structural characteristics thereof, the solar collector according to the present invention, is efficient, extremely inexpensive, light, easy and quick to assemble as well as simple to install.

The invention is susceptible to variants falling within the inventive concept.

All details may be replaced by equivalent elements and the materials, the shapes and the dimension may vary.

The embodiments of the heat exchange device and of the solar heat collector described above may be subjected - by a man skilled in the art with the aim of meeting contingent requirements - to modifications, adaptations and replacement of elements with other functionally equivalent elements, without departing from the scope of protection of the claims that follow. Each of the characteristics described as belonging to a possible embodiment may be obtained independently from the other described embodiments .

Claims

1. Heat exchange device (1) comprising:

- a substantially plate-like body (2) comprising an inner cavity (3) suitable to contain a fluid (50) , and further comprising a first wall (6) and a second wall (7);

- at least one inlet duct (4), suitable to allow the inflow of said fluid (50) into said inner cavity (3) ;

- at least one outlet duct (5) , suitable to allow the outflow of said fluid (50) from said inner cavity

(3); characterised in that:

- said body (2) comprises a plurality of connection portions (9, 10) between the first wall (6) and the second wall (7), said plurality of connection portions

(9, 10) defining a plurality of paths for said fluid (50) between at least one inlet duct (4) and at least one outlet duct (5), in said inner cavity (3) ;

- said inner cavity (3) is mainly extended along a development plane (P) substantially parallel to at least one of said first wall (6) and second wall (7) .

2. Heat exchange device (1) according to claim 1, wherein said body (2) is made in a single piece.

3. Heat exchange device (1) according to claim 1, wherein said body (2) is obtained by means of a first sheet (6) and a second sheet (7), manufactured separately and subsequently connected.

4. Heat exchange device (1) according to any one of the preceding claims, wherein the body (2) is made of synthetic material.

5. Heat exchange device (1) according to any one of claims 1-3, wherein the body (2) is made of metal material .

6. Heat exchange device (1) according to any one of the preceding claims, wherein the plurality of connection portions between the first wall (6) and the second wall

(7) comprises a first connection portion (9) extending along the perimetrical edge of said first wall (6) and second wall (7) .

7. Heat exchange device (1) according to any one of the preceding claims, wherein the plurality of connection portions between the first wall (6) and the second wall

(7) comprises second connection portions (10) arranged within the inner cavity (3) of the heat exchange device

(D •

8. Heat exchange device (1) according to claim 7, wherein said second connection portions (10) comprise bulges (10) , present on the inner surface of at least one of said first wall (6) and second wall (7), said bulges (10) being suitable to deflect the heat-conductive fluid (50) and to homogenize the flow thereof.

9. Heat exchange device (1) according to claim 8, wherein said bulges (10) are on the surface of both the first (6) and the second wall (7), said bulges (10) being mutually connected in such a manner to form said second connection portions (10) .

10. Heat exchange device (1) according to any one of the preceding claims, wherein the at least one inlet duct (4) and the at least one outlet duct (5) are provided with a connection sleeve (51) for connecting with an external system for the supply and conveyance of the heat-conductive fluid.

11. Heat exchange device (1) according to claim 10, wherein the at least one inlet duct (4) and at least one outlet duct (5) of the heat-conductive fluid (50) and the respective connection sleeves (51) are manufactured in a single piece with the body (2) of the heat exchange device (1) .

12. Heat exchange device (1) according to any one of the preceding claims, comprising a profile (53) extending from one of said first (6) and second wall (7), said profile (53) defining an accommodation for an edge of an upper cover portion.

13. Heat exchange device (1) according to any one of the preceding claims, wherein at least one of said first wall (6) and second wall (7) comprises elements (52) for fixing to an external mounting or installation system.

14. Heat exchange device (1) according to any one of the preceding claims, wherein one of said first wall (6) and second wall (7) comprises a photovoltaic or electrochemical coating for transforming solar energy into electrical energy.

15. Solar heat collector (100; 200) comprising a heat exchange device (1) according to any one of the preceding claims .

16. Solar collector (100; 200) according to claim 15, further comprising an insulation casing (101), suitable to insulate said heat exchange device (1) from heat exchange by conduction and from convection with the surrounding environment .

17. Solar collector (100; 200) according to claim 16, wherein said insulation casing (101) comprises a lower portion (102) for accommodating the heat exchange device

(1), said lower portion (102) comprising:

- a seat (106) suitable to receive - with geometric coupling - at least one portion of the body (2) of the heat exchange device (1); at least one hole (107) suitable to be geometrically coupled to the at least one inlet duct (4) of the heat exchange device (1); at least one further hole (108) suitable to be geometrically coupled to the at least one outlet duct (5) of the heat exchange device (1) ; a side frame (103; 203) .

18. Solar collector (100; 200) according to claim 17, wherein said insulation casing (101) further comprises heat insulation means (105; 205) for the lower portion

(102) .

19. Solar collector (100; 200) according to claim 18, wherein said lower portion (102) is made using heat- insulating synthetic material and wherein said heat insulation means for the lower portion are the heat- insulating synthetic material that forms the lower portion (102) .

20. Solar collector (100; 200) according to claim 18, wherein said heat insulation means for the lower portion comprise heat insulation material (105; 205) arranged between said lower portion (102) and the heat exchange device (1) .

21. Solar collector (100) according to claim 18, wherein a hollow volume (125) is comprised within the lower portion (102), said volume (125) being purposely arranged to accommodate insulation means, and wherein said heat insulation means for the lower portion comprise heat-insulation material (105) injected inside said hollow volume (125) of the lower portion (102) .

22. Solar collector (100; 200) according to any one of claims 17-21, wherein said lower portion for accommodating the heat exchange device is made in a single piece.

23. Solar collector (100; 200) according to any one of claims 17-22, wherein said lower portion for accommodating the heat exchange device comprises elements

(152) for fixing to a system for mounting or installing the collector.

24. Solar collector (100; 200) according to any one of claims 16-23, wherein said insulation casing (101) further comprises an upper transparent portion (104; 204), over the wall - exposed to the sun - of the heat exchange device (1), said upper transparent portion (104; 204) being a transparent panel made of synthetic material.

25. Solar collector (100; 200) according to claim 17, wherein the side frame (103, 203) is provided with a profile (153) extending from said frame, said profile

(153) defining an accommodation for an edge of an upper cover portion (104; 204) .

26. Solar collector (100; 200) according to claims 24 and 25, wherein the upper transparent portion (104; 204) is accommodated in said profile (153) of the frame.

27. Solar collector (100; 200) according to claim 24, comprising a heat exchange device according to claim 12, wherein the upper transparent portion (104; 204) is accommodated in the profile (53) the heat exchange device (1) is provided with.

28. Solar collector (100; 200) according to claim 24, wherein said upper transparent portion (104; 204) comprises a photovoltaic or electrochemical coating (199) for transforming solar energy into electrical energy.

29. Method for manufacturing a solar heat collector (100; 200), characterized in that it comprises the steps of: inserting - into a mould - a heat exchange device (1) having the characteristics according to one of claims 1 - 14; injecting - into said mould - heat-insulating synthetic material (105; 205) in a manner suitable to obtain a lower portion (102) surrounding the lower part of said device (1) and having a main development along a plane parallel to the development plane of the device.

30. Method for manufacturing a solar heat collector (100; 200) according to claim 29, characterized in that it further comprises the step of inserting a side frame (203) - into the mould - of such dimensions and at such position to surround the perimeter of the heat exchange device (1) , leaving a perimetrical space along the said perimeter; and in that said step of injecting comprises the injection - into said mould - of heat insulating synthetic material (205) in such a manner to fill said perimetrical space.

31. Method for manufacturing a solar heat collector (100; 200), characterized in that it comprises the following steps : manufacturing - by moulding - a heat exchange device (1) and a lower portion (102) for accommodating an insulation casing (101) for said device, in such a manner there is free space for heat insulation, suitable to accommodate heat-insulation material (105; 205), around at least one part of said device, said heat exchange device (1) having the characteristics according to one of claims 1 - 14, and said lower portion (102) comprising a seat (106) suitable to receive - with geometric coupling - at least one portion of the body of said heat exchange device (1), a side frame (103; 203), at least one hole (107) suitable to be geometrically coupled to at least one inlet duct (4) of said heat exchange device (1), at least one further hole (108) suitable to be geometrically coupled to at least one outlet duct (5) of the heat exchange device (1) ; injecting heat insulation material (105; 205) into said free space for heat insulation.

32. Method for manufacturing a solar heat collector (100) according to claim 31, wherein said free space for heat insulation is a hollow volume (125) obtained inside said lower portion (102) .

33. Method for manufacturing a solar heat collector (100; 200) according to claim 31 or 32, wherein the step of manufacturing - by moulding - comprises: manufacturing - in a single piece - the heat exchange device (1) and the lower portion (102) of the insulation casing (101) starting from synthetic material by means of a process belonging to the group comprising: rotational moulding, bi-injection, thermoforming twin sheet .

34. Method for manufacturing a solar heat collector (100; 200) according to claim 31 or 32 wherein the step of manufacturing - by moulding - comprises: manufacturing in a single piece the heat exchange device (1) starting from synthetic material by means of a process selected from among the following set: rotational moulding, bi-injection, thermoforming twin sheet; - manufacturing in a single piece - the lower portion (102) of an insulation casing (101) starting from synthetic material by means of a process selected from among the following set: rotational moulding, bi- injection, thermoforming twin sheet. assembling said device (1) and said lower portion

(102) .

35. Method for manufacturing a solar heat collector

(100; 200) according to one of claims 29-34 comprising the further step of: inserting an upper transparent portion (104; 204) as an upper cover for the assembly made up of the heat exchange device (1) and the lower portion (102) .