THERMAL SOLAR PANEL AND SOLAR ENERGY HEATING SYSTEM COMPRISING SUCH PANEL

The present invention refers to a thermal solar panel and to a solar energy heating system comprising such panel.

It is now known that the continuous growth of energy demand from the modern society, and mainly from the most advanced industrial companies, the more and more limited availability of fossil fuels and the increased sensitivity of the population towards the problem of emission in the atmosphere of carbon dioxide and other gases having adverse effect on the climate, have brought about the search and use of new energy sources with the progressive abandonment of energy sources of the traditional type in favour of renewable sources, namely not depending on sources that require very long time to be regenerated and therefore deemed adapted to be depleted. The renewable energy sources, then, in addition to renew their availability in extremely short times, produce, after heir use, a wholly neglected environmental pollution.

From such point of view, the art therefore has

developed in these last years solutions that allow efficiently and more effectively exploiting the renewable sources available in order to replace, or at least integrate the traditional energy systems. As known, above all in household contexts, heating systems with thermal solar panels are getting more and more widespread, and are adapted to obtain hot water from solar energy, water that can be used both for sanitary purposes, namely for personal hygiene, through house taps or in showers, or for washing dishes, for a dish-washing machines and for washing machines, and for the actual heating of the household environment.

In general, solar energy heating systems are composed of plane glass thermal solar panels or solar panels with vacuum tubes exposed to sun radiations, at least one tank for collecting heated water, possible pumps and electronic control units. Solar panels then operate as collectors of solar energy inside which water is heated. Obviously, the tank is used to accumulate heated water produced by panels, keeping it hot also for several days, in order to use it when it is actually necessary or in order to have a good reserve of hot water to be used in days when the sun is scarce.

Glass solar panels are composed of a glass that is transparent to sunlight, but opaque to infrared rays that

are thereby kept inside the panel itself. The surface of this type of panels can be treated or not with products that improve its efficiency (namely its capability of "keeping" rays).

Vacuum solar panels instead appear as glass tubes, inside which a very small (vacuum) air pressure is applied, to prevent heating from being given away (thermos effect) . Inside it, therefore, a heat-absorbing element is placed, generally composed of a copper tube.

Currently, known thermal solar panels however, in addition to being extremely costly, are technically complex and relatively fragile, above all if exposed to particularly adverse climatic conditions, such as for example in case of hail storms.

Known heating systems instead are divided into natural circulation systems and forced circulation systems: natural circulation solar systems are single- block closed-circuit systems, that operate without needing either pumps or electric components: in this case, heated water inside the panels rises by convection (thermo-siphon effect) towards the tank, then flowing into the house circuit. In forced circulation solar system, the tank instead is assembled separately and liquid in the primary circuit is pushed by a circulating pump that is operated by an electronic unit that compares the temperatures of

panels and water in the accumulating tank detected by suitable probes.

Currently, a good solar system manages to cover even more than 80% of the yearly demand for hot water, thereby greatly reducing energy expenses and emission of obnoxious gases in the atmosphere. The use, instead, of known systems for heating the house environment nowadays allows obtaining limited savings (it is difficult to obtain a greater saving than 30 - 50% of heating expenses) : moreover, to reach a good environment heating, it is necessary to support high expenses to install a high enough number of solar panels, a big-sized tank, and a heating plant with radiating panels possibly inserted below the floor.

In such context, it is therefore natural that the art evolves aiming to obtain solutions that offer energy systems characterised by a higher and higher degree of thermal recovery, efficiency and optimisation, due both to economic aspects and to environmental compliance aspects.

Therefore, object of the present invention is solving the above prior art problems by providing a thermal solar panel that is cheaper and can be more easily made with respect to prior art solar panels.

Another object of the present invention is providing a solar energy heating system that is more efficient and,

at the same time, cheaper than prior art energy systems.

The above and other objects and advantages of the invention, as will appear from the following description, are obtained with a thermal solar panel as described in claim 1.

Moreover, the above and other objects and advantages of the invention are obtained with a solar energy heating system comprising such panel as described in claim 8.

Preferred embodiments and non-trivial variations of the present invention are the subject matter of the dependent claims.

It will be immediately obvious that numerous variations and modifications (for example related to shape, sizes, arrangements and parts with equivalent functionality) could be made to what is described, without departing from the scope of the invention as appears in the enclosed claims.

The present invention will be better described by some preferred embodiments thereof, provided as a non- limiting example, with reference to the enclosed drawings, in which:

FIGURE Ia shows a side sectional view of a preferred embodiment of a thermal solar panel according to the present invention;

FIGURE Ib shows a side sectional view of another

preferred embodiment of a thermal solar panel according to the present invention;

FIGURE 2 shows a block diagram showing a preferred embodiment of the heating system according to the present invention;

FIGURE 3 shows a front sectional view of a preferred embodiment of a component of the heating system according to the present invention.

With reference to FIGURES Ia and Ib, it is possible to note that a preferred embodiment of the thermal solar panel 1 according to the present invention comprises at least one casing 3 made of opaque material to infrared rays of sun rays R, inside which at least one layer of material 5 is arranged, adapted to be impregnated with fluid F to be heated, preferably water, at least one upper side 3a of such casing 3 being equipped with delivering means 6 of such fluid on such layer of material 5 adapted to be impregnated and at least one lower side 3b of such casing 3 being equipped with collecting means 7 of such heated fluid F _c on such layer of material 5 adapted to be impregnated by the thermal energy kept inside such casing 3 and generated by such infrared rays, the layer of material 5 adapted to be impregnated being suitable for conducting, by gravity, fluid F from delivering means 6 to collecting means 7.

Preferably, the casing 3 of opaque material to infrared rays is made of a black-coloured film of stabilised plastic material, therefore greatly free from thermal dilatation phenomena. Such film is then bent in such a way as to show its edged 3c oriented upwards and to form a pocket inside which the layer of material 5 adapted to be impregnated is inserted. Preferably, the layer of material 5 adapted to be impregnated is made of a non- woven fabric: as known, the non-woven fabric is a polymeric material composed of a series of continuous and parallel threads, transversally overlapped to a series of extruded, softened threads welded in their intersection points .

The delivering means 6 are preferably composed of at least one duct for fluid F equipped with at least one delivering nozzle 6a (preferably a plurality of suitably- spaced delivering nozzles 6a) adapted to deliver fluid F on the upper surface of the layer of material 5 adapted to be impregnated.

In a preferred embodiment thereof, as shown for example in FIGURE Ia, the collecting means 7 are represented by the bend arranged on the lower side 3b of the casing 3, such bend being obtained from the pocket- shaped bending of the film of stabilised plastic material making the casing 3 itself.

Alternatively, as shown for example in FIGURE Ib, the collecting means 7 could be made as at least one duct equipped with at least one slit 7a for collecting the heated fluid F _c coming from the layer of material 5 adapted to be impregnated.

As they are made, the collecting means 7 therefore allow channelling the heated fluid F _c from the thermal solar panel 1 towards a separate and distinct collecting tank.

Once the thermal solar panel 1 according to the present invention is arranged suitably oriented towards the sun rays R and adequately slanted, fluid F is delivered by the delivering means 6: fluid F is then distributed on the upper surface of the layer of material 5 adapted to be impregnated and, by sliding thereon due to the gravity force, proceeds downwards to be then collected by the collecting means 7. However, during the step of staying onto the layer of material 5 adapted to be impregnated, fluid F passes to a state with heated fluid F _c (state in which it is collected by the 9 collecting means 7) through a heating step F _R by the thermal energy kept inside the casing 3. Actually, the amount of thermal energy transferred to the fluid is a function of the stay time of the fluid itself on the layer of material 5 adapted to be impregnated, and therefore of the time the

fluid takes to travel along the distance that can be found between delivering means 6 and collecting means 7 on the surface of the layer of material 5 adapted to be impregnated. The amount of fluid heating can then be easily adjusted through numerous building factors for the thermal solar panel 1 according to the present invention, such as for example: slanting imposed to panel 1, that affects the fluid sliding speed on the layer of material 5 adapted to be impregnated and on the incidence of rays R on the layer itself; and/or length L of the layer of material 5 adapted to be impregnated; and/or type of material of which the layer of material 5 adapted to be impregnated and/or the casing 3 are made.

In addition, the thermal solar panel 1 according to the present invention could be equipped with at least one internal temperature sensor 9 that, by cooperating with suitable and substantially known control means, points out the temperature reached inside the casing 3 to manage the optimum operation of the panel 1 itself.

Advantageously, the operating positioning of the thermal solar panel 1 according to the present invention is extremely practical and easy: due to its own simple and sturdy structure, in addition to allow the use of

classical support structures, the thermal solar panel 1 can also be directly rested on the ground, possibly by interposing at least one layer of insulating material 11: if the ground is plane, to obtain the desired slanting for the resting surface of the panel 1, it is possible to make suitably slanted embankments, possibly covered with at least one layer of plastic material, such as for example NYLON®,- through a suitable machine, in order to avoid washing away the ground and an undesired growth of grasses .

With reference now to FIGURE 2, it can be noted that the solar energy heating system 100 according to the present invention comprises:

- at least one thermal solar panel 1 as previously described;

- at least one tank 101 for collecting the heated fluid F _c from the thermal solar panel 1; in particular, the tank

101 is connected to the collecting means 7 of the thermal solar panel 1 through at least one suitable channelling

102 to receive and store the heated fluid F _c collected by such means 7 ;

- at least one radiating dissipator 103 supplied by at least one delivery duct 105 of the heated fluid F _c from the tank 101; the radiating dissipator 103 is therefore suitable to dissipate in the outside environment of a user

104, heating him, the thermal energy contained inside the heated fluid F _c ;

- at least one duct 106 for recovering fluid F cooled by the radiating dissipator 103 and for delivering it to the delivering means 6 of the thermal solar panel 1; possibly, along the recovering duct 105, it is possible to provide at least one spare tank 107 for the supply fluid F of the del thermal solar panel 1.

Obviously, the system 100 according to the present invention can comprise an adequate number of pumps 109, 111, 113 and/or 115 suitably arranged along the ducts 102, 105 and/or 106 to allow circulating the heated fluid F _c from the solar panel 1 or the cooled fluid inside the system 100 itself.

The system 100 according to the present invention also allows using the heated fluid F _c to heat water required by the user 104, in particular for services that can require the delivery of hot water such as, for example, showers, baths, basins, swimming pools, etc. In such case, it is possible to provide that at least one duct 112 for supplying hot drinkable water of the hydraulic plant of the user 104 passes inside the tank 101 for collecting the heated fluid F _c , such duct being preferably of the serpentine type due to thermal exchange efficiency reasons, so that water passing inside the

supply duct 114 is heated by the heated fluid F _c contained inside the tank 101 before being entered in the hot water plant of the traditional hydraulic plant. Possibly, it could be provided, downstream of the tank 101, to connect the supply duct 112 to at least one electric water heater or boiler 114: in such a way, the electric heater or boiler 114 could further heat the water already heated in the tank 101 to reach the temperature required by the user and possibly not obtained by the sole thermal exchange with the heated fluid F _c . Obviously, the section of duct 112 passing inside the tank 101 could be replaced by a common fluid/water heat exchanger.

With reference now to FIGURE 3, it is possible to note that a preferred embodiment of the radiating dissipator 103 of the system 100 according to the present invention comprises at least one radiating module 117, each radiating module 117 being composed of at least one casing 119 made of thermally conducing material, such as for example polyethylene, inside which at least one layer of material 121 adapted to be impregnated by the heated fluid F _c is arranged, at least one upper side of such casing 119 being equipped with delivering means 123 for such heated fluid F _c on such layer of material 121 adapted to be impregnated and at least one lower side of such casing 3 being equipped with collecting means 125 of the

fluid F cooled on such layer of material 121 adapted to be impregnated, having given thermal energy outwards through the casing 119, the layer of material 121 adapted to be impregnated being adapted to conduce by gravity the fluid F from the delivering means 123 to the collecting means 125.

Also in this case, the layer of material 121 adapted to be impregnated is preferably made of a non-woven fabric.

Similarly, the delivering means 123 are preferably composed of at least one duct of the heated fluid F _c connected to the delivery duct 105 and equipped with at least one delivering nozzle (preferably a plurality of suitably spaced delivering nozzles) suitable to deliver the heated fluid F _c on the upper surface of the layer of material 121 adapted to be impregnated.

The collecting means 125 are preferably made as at least one collecting basin of the cooled fluid coming from the layer of material 121 adapted to be impregnated connected to the recovering duct 106 by means of at least one discharge duct 127, possibly by interposing at least one delivery pump 129.

Once the heated fluid F _c is delivered by the delivering means 123, it impregnates the layer of material 121 adapted to be impregnated and, proceeding downwards

due to the gravity force in order to be then collected by the collecting means 125, gives thermal energy outside through the casing 117. Also in this case, the amount of thermal energy transferred by the heated fluid F _c outside is function of the stay time of the fluid itself on the layer of material 121 adapted to be impregnated, and therefore of the time the fluid spent traveling along the distance between the delivering means 123 and the collecting means 125 along the layer of material 121 adapted to be impregnated.

Obviously, the number of radiating modules 117 to be arranged in series is various and depends on the sizes of the environment to be heated with heat coming from the heated fluid F _c .

It must be noted that, advantageously, by connecting the delivering means 123 to a duct carrying fluid at a lower temperature than the ambient one, the radiating dissipator 103 operates as air conditioner.

Merely as an example, the Applicant has discovered that, by using a solar energy heating system 100 according to the present invention, sized as follows:

- 90 m ² of total surface of thermal solar panels 1;

- 6000 1 of reserve with heated fluid F _c contained in the tank 101;

- 70 m ² of total surface for the thermal exchange of

radiating dissipators 103; for heating a room of 80 m ² , savings have been about 2/3 with respect to costs required by a traditional heating system.

In order to optimise the circulation of air heated by the radiating dissipators 10, favouring its convective motions and making its distribution more homogeneous inside places to be heated, it is possible to provide that such air is channelled to be punctually diffused by means of suitable mouths, possibly through pumps whose operation can be controlled by managing means through the use of substantially known thermostats.