Heat storage device

Abstract

An electrically powered heat storage device (1), comprising: - a thermally insulating casing (2), defining at least a main cavity (3) in use closed and at least thermally insulated from an external environment; - a heat accumulator (4) arranged in said main cavity (3) and apt to be heated by, through or by effect of, an electric current; - at least a heat exchanger (5), comprising a duct apt to allow the passage of a heat exchange fluid (6), the heat exchanger (5) being operatively connected to said heat accumulator (4), and being configured to receive heat from said heat accumulator (4) and to transfer said heat to said heat exchange fluid (6); - a power supply group or system (7), comprising at least a first and a second electrical power supply terminal (7a, 7b), configured to be powered, in use, by an electrical power supply source (200), preferably by at least one among an electricity grid and / or electric generator, a photovoltaic cell or an electric solar panel, said power supply group or system (7) being operatively coupled to said heat accumulator (4) and being configured to determine a heating of said heat accumulator (4) when electrically powered by said power supply group or system (7).

Description

[0001] DESCRIPTION

[0002] HEAT STORAGE DEVICE

[0003] Field of the art

[0004] The present disclosure relates to the field of the heat storage devices, and in detail it relates to an electrically powered heat storage device.

[0005] Known art

[0006] The heat accumulators are devices used to store thermal energy and to return it to users if requested.

[0007] The heat accumulators accumulate thermal energy through heating a body, typically a solid or liquid body and more rarely gas. The capability of storing thermal energy by a material or a substance is expressed by its specific heat; in case the substance used to store the heat is involved in a phase transition (for example the water which boils, passing from the liquid state to the gaseous state), the storage capability increases due to the contribution given by the latent heat.

[0008] Examples of heat accumulators for example are the traditional boiler water heaters, which can be traditionally connected to the electricity grid and which heat the water through the heat induced by an electrical resistance.

[0009] Heat accumulators are also known which are connected to fluid-powered solar panels. In the solar panels a fluid circulates which is heated by the sun and which is stored, when it comes out from the solar panel, in the heat accumulator.

[0010] The current increase in energy costs leads to a need for optimizing the modes with which a heated fluid is produced, independently from the application.

[0011] Summary

[0012] The object of the present invention is to describe an electrically powered heat storage device, which allows to store heat and yield it to a fluid in an energy optimized way.

[0013] The object of the present disclosure is herein described in some of its salient aspects which can be combined to each other or to parts of the detailed description and / or claims.

[0014] According to the present disclosure an electrically powered heat storage device (1 ) is firstly described, comprising:

[0015] - a thermally insulating casing (2), defining at least a main cavity (3) in use closed and at least thermally insulated from an external environment; a heat accumulator (4) arranged in said main cavity (3) and apt to be heated by, through or by the effect of, an electric current; at least a heat exchanger (5), comprising a duct apt to allow the passage of a heat exchange fluid (6), the heat exchanger (5) being operatively connected to said heat accumulator (4), and being configured to receive heat from said heat accumulator (4) and to transfer said heat to said heat exchange fluid (6); a power supply group or system (7), comprising at least a first and a second electrical power supply terminal (7a, 7b), configured to be powered, in use, by an electrical power supply source (200), preferably by at least one among an electricity grid and / or electric generator, a photovoltaic cell or an electric solar panel, said power supply group or system (7) being operatively connected to said heat accumulator (4) and being configured to determine a heating of said heat accumulator (4) when electrically powered by said power supply group or system (7).

[0016] According to an additional non-limiting aspect, said heat accumulator (4) is configured to yield heat at least during operation, preferably in proportional function, to an amount of heat exchange fluid (6) flowing in the duct of the heat exchanger (5).

[0017] According to an additional non-limiting aspect, said main cavity (3) insulates a herein present gas from an external atmosphere.

[0018] According to an additional non-limiting aspect, said device (1 ) is configured and specifically intended to implement a module, in use electrically connected, and preferably removably electrically connectable, to said at least an electrical power supply source (200), preferably to said at least a photovoltaic cell or to said at least an electric solar panel.

[0019] According to an additional non-limiting aspect, said device (1 ), preferably said module, implements a transformation of said electrical power supply source (200) in a heat storage source and / or is of plug-and-play type.

[0020] According to an additional non-limiting aspect, said device (1 ) is an integrated device wherein said casing (2), said heat accumulator (4), said heat exchanger (5) and said power supply group or system (7) are assembled in one single structure.

[0021] According to an additional non-limiting aspect, said casing (2), said heat accumulator (4), said heat exchanger (5) and said power supply group or system (7) are mutually constrained and can be moved, transported or installed as a single assembly.

[0022] According to an additional non-limiting aspect, said casing (2) contains a heat conducting fluid (8).

[0023] According to an additional non-limiting aspect, said heat conducting fluid (8) is placed under pressure.

[0024] According to an additional non-limiting aspect, said heat exchanger (5) is arranged in position spaced apart from, and not in contact with, said heat accumulator (4).

[0025] According to an additional non-limiting aspect, said heat conducting fluid (8), in use, comes in contact with said heat accumulator (4) and with said heat exchanger (5) and transfers heat from said heat accumulator (4) to said heat exchanger (5).

[0026] According to an additional non-limiting aspect, said heat exchange fluid (6) and / or said heat conducting fluid (8) is a liquid or a gas.

[0027] According to an additional non-limiting aspect, said heat exchange fluid (6) and / or said heat conducting fluid (8) comprises at least one among the following fluids: water, air, nitrogen, carbon dioxide, sodium, compound derived from methane, compound derived from ethane, compound derived from propane, compound derived from butane, a zeotropic mixture, an azeotropic mixture, a mixture containing saturated hydrocarbons, a mixture containing inorganic compounds with a molar mass lower than 100 or a mixture containing organic compounds with molar mass higher than 100.

[0028] According to an additional non-limiting aspect, said heat accumulator (4) is substantially solid and / or rigid, and it is substantially made of metallic material, optionally of ferrous material and / or of non-ferrous material.

[0029] According to an additional non-limiting aspect, said heat accumulator (4) comprises a set of elements in granular form, optionally made of metallic material, for example ferrous or non-ferrous material.

[0030] According to an additional non-limiting aspect, said heat accumulator (4) is configured to store heat for specific heat properties of said metallic material, optionally of said ferrous material.

[0031] According to an additional non-limiting aspect, said heat accumulator (4) comprises a metallic mass substantially implemented in a single bloc.

[0032] According to an additional non-limiting aspect, said heat accumulator (4) comprises a plurality of elements (4e) coupled with each other. According to an additional non-limiting aspect, said elements (4e) are juxtaposed.

[0033] According to an additional non-limiting aspect, said elements (4e) are made of said metallic material, optionally ferrous material.

[0034] According to an additional non-limiting aspect, each element (4e) of said plurality of elements (4e) assumes a substantially planar and / or laminar shape, and / or is positioned near, and separated from, at least an additional element (4e) of said plurality of elements (4e).

[0035] According to an additional non-limiting aspect, the plurality of elements (4e) are aligned or juxtaposed on substantially parallel planes, or planes tilted by an angle lower than 10°, preferably 8°, with respect to each other, and in particular they are aligned along a direction substantially tilted, preferably orthogonal, to each one of said parallel planes.

[0036] According to an additional non-limiting aspect, said metallic mass comprises at least a hole (4f) configured to allow the passage of said heat conducting fluid (8).

[0037] According to an additional non-limiting aspect, said heat accumulator (4) is arranged in said main cavity (3).

[0038] According to an additional non-limiting aspect, said heat accumulator (4) is positioned in a predefined position inside said main cavity (3).

[0039] According to an additional non-limiting aspect, said heat accumulator (4) is positioned at a predefined distance from said casing (2).

[0040] According to an additional non-limiting aspect, said casing (2) is configured to keep at least said main cavity (3) under pressure, in particular at a higher pressure than the environmental pressure.

[0041] According to an additional non-limiting aspect, said heat exchanger (5) comprises a bent duct. According to an additional non-limiting aspect, said bent duct implements a serpentine arranged on a plane or assuming a substantially three-dimensional shape developing along at least a first and a second direction substantially orthogonal to each other.

[0042] According to an additional non-limiting aspect, said bent duct is configured to allow a flow of said heat exchange fluid (6).

[0043] According to an additional non-limiting aspect, said heat exchanger (5) comprises a first and a second terminal (5i, 5o), respectively configured to be connected with a thermal user (100), positioned outside said device (1 ) and / or in remote position with respect to said device (1 ).

[0044] According to an additional non-limiting aspect, said thermal user (100) in use removes heat from said heat exchange fluid (6).

[0045] According to an additional non-limiting aspect, said power supply group or system (7) comprises an electric regulator configured to regulate, preferably automatically, the heating and / or a temperature of said heat accumulator (4) and / or to regulate, preferably automatically, a current absorption by said power supply source (200), preferably said at least a photovoltaic cell or said at least an electric solar panel.

[0046] According to an additional non-limiting aspect, said heat accumulator (4) is configured to reach a temperature at least equal to 300°C, preferably at least equal to 400°C, still more preferably at least equal to 500°C or to 600°C or to 1000°C and / or said device (1 ) is configured to bring said heat exchange fluid (6) at a temperature at least equal to 90°C, or at least equal to 150°C, or at least equal to 300°C, or at least equal to 450°C.

[0047] According to an additional non-limiting aspect, said heat exchanger (5) is part of, and / or is integrated in, said power supply group or system (7). According to an additional non-limiting aspect, said power supply group or system (7) comprises a radio frequency inductor (9).

[0048] According to an additional non-limiting aspect, said radio frequency inductor (9) comprises an induction coil (9c) arranged around said heat accumulator (4).

[0049] According to an additional non-limiting aspect, said heat exchanger (5) is part of said induction coil (9c) and / or said induction coil (9c) implements at least part of said heat exchanger (5).

[0050] According to an additional non-limiting aspect, the device (1 ) comprises at least un fluid forced circulation device (14), configured to force a flow of the heat conducting fluid (8) inside said main cavity (3).

[0051] According to an additional non-limiting aspect, said fluid forced circulation device (14) is configured to favour a heat exchange between said heat accumulator (4) and said heat exchanger (5).

[0052] According to an additional non-limiting aspect, said heat accumulator (4) is arranged at a first quote or lies between a first and a second quote.

[0053] According to an additional non-limiting aspect, said fluid forced circulation device (14) is arranged at a lower quote than said first quote, or at a lower quote than said first quote and said second quote.

[0054] According to an additional non-limiting aspect, said fluid forced circulation device (14) comprises a fan or a pump.

[0055] According to an additional non-limiting aspect, said device (1 ) comprises a thermal insulator (10), preferably substantially rigid and optionally made of ceramic material. According to an additional non-limiting aspect, said thermal insulator (10) is arranged in said main cavity (3).

[0056] According to an additional non-limiting aspect, said thermal insulator (10) is positioned at a predefined distance with respect to said heat accumulator (4).

[0057] According to an additional non-limiting aspect, said thermal insulator (10) surrounds at least partially said heat accumulator (4).

[0058] According to an additional non-limiting aspect, said heat accumulator (4) is arranged substantially inside said thermal insulator (10).

[0059] According to an additional non-limiting aspect, said radio frequency inductor (9) is arranged substantially outside said thermal insulator (10).

[0060] According to an additional non-limiting aspect, said thermal insulator (10) is positioned in a predefined position with respect to said heat accumulator (4) and preferably substantially under said heat accumulator (4), preferably at a lower quote than said first quote, or lower than said first quote and said second quote.

[0061] According to an additional non-limiting aspect, said thermal insulator (10) defines a secondary cavity (3s) distinct with respect to said main cavity (3) and open on said main cavity (3).

[0062] According to an additional non-limiting aspect, said induction coil (9c) lies outside, and surrounds partially, said thermal insulator (10).

[0063] According to an additional non-limiting aspect, said thermal insulator (10) acts as support for said induction coil (9c).

[0064] According to an additional non-limiting aspect, said thermal insulator (10) is made of a material apt to allow a substantial passage of and electromagnetic radiation induced by said induction coil (9c).

[0065] According to an additional non-limiting aspect, said thermal insulator (10) is connected to an internal wall of said casing (2).

[0066] According to an additional non-limiting aspect, said thermal insulator (10) comprises at least a first heat exchange hole (10f), putting said main cavity (3) and said secondary cavity (3s) in communication.

[0067] According to an additional non-limiting aspect, said heat exchanger (5) is arranged in said secondary cavity (3s) and receives heat from said heat accumulator (4) through said at least a first heat exchange hole (1 Of).

[0068] According to an additional non-limiting aspect, said thermal insulator (10) comprises a first heat exchange hole (1 Of) and a second heat exchange hole (1 Of).

[0069] According to an additional non-limiting aspect, said first heat exchange hole (1 Of) is arranged on a first side of said thermal insulator (10), and said second heat exchange hole (1 Of) is arranged on a second side of said thermal insulator (10).

[0070] According to an additional non-limiting aspect, said first side is opposite to said second side.

[0071] According to an additional non-limiting aspect, said thermal insulator (10) implements a bottom wall of said main cavity (3).

[0072] According to an additional non-limiting aspect, said fluid forced circulation device (14) is arranged substantially corresponding to said secondary cavity (3s) and forces a flow of said heat conducting fluid (8) from said main cavity (3) to said secondary cavity (3s) through said at least a first heat exchange hole (1 Of).

[0073] According to an additional non-limiting aspect, said fluid forced circulation device (14) is an electric fluid forced circulation device.

[0074] According to an additional non-limiting aspect, said fluid forced circulation device (14) is electrically connected to and operatively controlled by said power supply group or system (7).

[0075] According to an additional non-limiting aspect, said power supply group of system (7) comprises a data processing unit (7a) configured: to regulate automatically an electric current absorbed by said power supply source (7), and / or to impose a regulation of a flow of said heat exchange fluid (6) inside said heat exchanger (5), and / or to regulate automatically a rotation speed of said fluid forced circulation device (14); preferably wherein the data processing unit is configured to regulate automatically said electric current absorbed by said power supply source (7) and said rotation speed of said fluid forced circulation device (14) jointly, and / or depending on each other, and / or in synergistic way.

[0076] According to an additional non-limiting aspect, said heat accumulator (4) is configured to be heated by Joule effect.

[0077] According to an additional non-limiting aspect, said power supply group or system (7) comprises an electrical power supply circuit ending on said first and second electrical power supply terminal (7a, 7b).

[0078] According to an additional non-limiting aspect, said power supply group or system (7) comprises a first and a second contact terminal (7c, 7d) respectively connected to a first portion and to second portion of said heat accumulator (4) and configured to make, in use, an electric current to flow inside said heat accumulator (4).

[0079] According to an additional non-limiting aspect, said plurality of elements (4e) are electrically connected in series.

[0080] According to an additional non-limiting aspect, said first contact terminal (7c) is electrically connected to a first element (4e) of said plurality of elements (4e) and said second contact terminal (7d) is connected to a second element (4e) of said plurality of elements (4e).

[0081] According to an additional non-limiting aspect, each element (4e) has substantially curved shape or detecting at least one, preferably a plurality of, “V” or “U” sequentially connected to each other at ends of their legs.

[0082] According to an additional non-limiting aspect, the connection sequence detects a curved path for said electric current, preferably so as to maximize the electrical resistance met in said element (4e).

[0083] According to an additional non-limiting aspect, each element (4e) comprises a first terminal portion (4b) and a second terminal portion (4c) respectively arranged on a first side and on a second side of said element (4e).

[0084] According to an additional non-limiting aspect, said first side is opposite to said second side.

[0085] According to an additional non-limiting aspect, said first element (4e) is directly electrically connected to said second element (4e) at said first terminal portion (4b) or, alternatively, at said second terminal portion (4c).

[0086] According to an additional non-limiting aspect, once defined a first, a second, a third and a fourth element (4e): said first element (4e) and said second element (4e) are directly electrically connected at said first terminal portion (4b) and insulated and separated at said second terminal portion (4c), said second element (4e) and said third element (4e) are directly electrically connected at said second terminal portion (4c) and insulated and separated at said first terminal portion (4b).

[0087] According to an additional non-limiting aspect, said device (1 ) comprises a plurality of spacers (11 ) at least interposed between said first element (4e) and said second element (4e).

[0088] According to an additional non-limiting aspect, said spacers (11 ) have preferably disc-like and / or planar shape.

[0089] According to an additional non-limiting aspect, said spacers (11 ) are electrically insulating.

[0090] According to an additional non-limiting aspect, said element (4e) comprises at least a through-hole (12) and an insulator (13) arranged in said through-hole (12).

[0091] According to an additional non-limiting aspect, said insulator (13) has a service hole. According to an additional non-limiting aspect, said insulator (13) is electrically insulating.

[0092] According to an additional non-limiting aspect, said insulator (13) has a smaller size than the size of the through-hole (12) of the element (4e).

[0093] According to an additional non-limiting aspect, a dimensional ratio between the size of the insulator (13) and the size of the through-hole (12) is such as to allow a compensation of a dimensional variation of said through-hole (12) as a function of a thermal expansion or contraction determined by the heating of the element (4e).

[0094] According to an additional non-limiting aspect, said thermal insulator (10) can comprise at least one among the following materials: ceramic fibre, glass fibre, rock wool, in particular compacted rock wool, aluminium silicate, refractory ceramic, high temperature polyurethanes, silica aerogel.

[0095] According to an additional non-limiting aspect, said insulator (13) comprises at least one among the following materials: ceramic, bakelite, mica, micanite, glass.

[0096] According to an additional non-limiting aspect, said radio frequency inductor (9) comprises an impedance adapter, configured to adapt, optionally in real time, an impedance shown by said induction coil (9c).

[0097] According to an additional non-limiting aspect, said power supply group or system (7) is configured to perform a conversion from direct current to alternating current and / or to perform a frequency conversion of an alternating current received as input or fed as output.

[0098] According to an additional non-limiting aspect, said through-hole (12) is configured to house a tie rod intended for compaction and to keep in a predefined positional relationship said plurality of elements (4e).

[0099] According to the present disclosure the use of the device (1 ) is described according to one or more of the herein described aspects in association to at least an electric solar panel.

[0100] According to the present disclosure the use of the device (1 ) is described for producing heat and / or for storing heat in said heat accumulator (4), and / or for releasing at least part of the heat stored in said heat accumulator (4) through said heat exchange fluid (6).

[0101] According to an additional non-limiting aspect, said use comprises an electrical power supply of the power supply group or system (7), through a power supply source (200).

[0102] According to an additional non-limiting aspect, said power supply is selectively activated according to an electricity cost criterion.

[0103] Figures

[0104] The following detailed description will be referred to some preferred embodiments which are represented in the enclosed figures. A brief description of the latter is provided hereinafter.

[0105] - Figure 1 illustrates a perspective view of a first embodiment of a device the present disclosure relates to.

[0106] - Figure 2 illustrates an exploded view of a device similar to that of figure 1 .

[0107] - Figure 3 illustrates a perspective view partially transparent of an additional embodiment of a device the present disclosure relates to.

[0108] - Figure 4 illustrates an exploded view of the device of figure 3.

[0109] - Figure 5 illustrates a top detailed view of part of a heat accumulator of the embodiment of figure 3 and 4.

[0110] - Figure 6 illustrates a detailed view of a pair of sheets implementing the heat accumulator.

[0111] - Figure 7 illustrates an exploded view showing how said sheets are spaced apart therebetween by spacers, and suitably kept therebetween in a mutual spatial position.

[0112] Detailed description

[0113] The present disclosure relates to an electrically powered heat storage device; such device is designated by the numeral reference 1 .

[0114] The device 1 first of all comprises a thermally insulating casing 2, defining at least a main cavity 3 in use closed and at least thermally insulated from an external environment. As it will be further clear by the following part of description, the main cavity 3 insulates a herein present gas from an external atmosphere.

[0115] The device 1 comprises a heat accumulator 4, apt to be heated by, through or by the effect of, an electric current.

[0116] As it will appear clear from the following description, said electric current can be a substantially direct electric current or it can be an alternating electric current.

[0117] The main cavity 3 of the casing 2 can be kept at environmental pressure or it can be pressurized, even at room temperature (ideally 20°C - 25°C) or due to the effect of the heating of the heat accumulator 4.

[0118] The material of the casing 2 can be for example aluminium silicate. The heat accumulator 4 is positioned inside said main cavity 3. As it will appear clear from the specific description of the preferred embodiments, the heating of the heat accumulator 4 takes place directly by the effect of said electric current, and in particular by Joule effect, or indirectly, through electromagnetic induction.

[0119] The device 1 further comprises a heat exchanger 5 which comprises a duct configured with the purpose of allowing the passage of a heat exchange fluid 6. As it will appear clear from the preceding description, the heat exchanger 5 being heated by the heat stored by the heat accumulator 4, absorbs from the latter part of its heat, and yields such part to the heat exchange fluid 6, which is made to circulate outside the device 1 and it cools down. Consequently, in use the circulation of the heat exchange fluid 6 in the heat exchanger 5 determines a decrease in the heat stored in the heat accumulator 4. Such heat can be regained by an additional heating.

[0120] Then, the heat exchanger 5 is operatively coupled to said heat accumulator 4 and it is configured to receive heat from said heat accumulator 4 and to transfer said heat to said heat exchange fluid 6. In particular, the heat accumulator 4 is configured to yield heat to the heat exchanger, and then to the heat exchange fluid 6, depending upon the amount or flow of fluid which, in use, flows inside the duct of the heat exchanger 6.

[0121] The device 1 further comprises a power supply group or system 7, comprising at least a first and a second electrical power supply terminal 7a, 7b.

[0122] The power supply group or system 7 is operatively coupled to said heat accumulator 4, and in particular it is coupled directly (in case of heating of the heat accumulator 4 by Joule effect) or indirectly (in case of heating of the accumulator 4 by electromagnetic induction). The power supply group or system 7 is configured to determine a heating of said heat accumulator 4 when powered electrically.

[0123] The first and the second electrical power supply terminal 7a, 7b are configured to be powered, in use, by an electrical power supply source 200, preferably by at least one among an electricity grid and / or electric generator, a photovoltaic cell or an electric solar panel.

[0124] Although theoretically the electrical power supply source 200 can be any source, the use of the device 1 with electrical power supply coming from a photovoltaic cell or at least an electric solar panel makes that the device 1 becomes a device configured and specifically intended to implement a module, in use electrically connected, and preferably removably electrically connectable, to said at least a photovoltaic cell or to said at least an electric solar panel.

[0125] The device 1 , the present disclosure relates to, can be advantageously activated to accumulate heat when the energy tariffs are lower; in an embodiment, a data processing unit of the device 1 can be configured to activate the device 1 at set times, and coherent with the time intervals in which the energy tariffs are lower. The heat storage then is made not only effective from a thermodynamic point of view, but also effective from an economic point of view.

[0126] In a not-limiting embodiment, the device 1 is intended to become a plug-and-play module for pre-existing photovoltaic installations, and / or configured to be powered by electrical grids or by external generators, in which it is simply sufficient to connect the terminals of the photovoltaic panel to the first and second electrical power supply terminal 7a, 7b, and to connect the terminals of the heat exchanger 5 to an additional circuit to make the device 1 operational so that is can generate hot fluid.

[0127] The electrical photovoltaic panels are quite delicate devices and in order to operate at maximum efficiency they require to be connected to the electric circuits which absorb at least part of the ideally producible electric current. The electric photovoltaic panels do not tolerate the connection to substantially open circuits, in particular when strongly irradiated by the sun.

[0128] The electric solar panels may encounter various problems, thereamong those deriving from an open circuit or excessive electric currents. An open circuit occurs when there is an interruption or a disconnected connection in the electric circuit of the solar panels. In other words, the solar energy is collected by the panels, but it cannot flow through the electric circuit to be used or stored.

[0129] In an open circuit, the electric current cannot flow, then the solar panels cannot generate electrical energy. The solar cells of the panel continue to try to produce electric current, but this cannot be dissipated by any load. Consequently, the electric solar panel overheats. This can damage irreparably the solar cells and the panel itself.

[0130] The device 1 fits-in well in a pre-existing system as device for absorbing electric current not absorbed by a primary load 300, and can be connected in parallel to the primary load 300.

[0131] The device 1 can operate with a heating of the heat accumulator 4, induced by the power supply group or system 7, simultaneously to the heat collection performed by the circulation of the heat exchange fluid 6 in the heat exchanger 5.

[0132] Generically, to the purposes of the present disclosure, the heat exchange fluid 6 or the heat conducting fluid 8 can be fluid or gas, and they can be for example water, air, nitrogen, carbon dioxide, sodium; more generally, the heat exchange fluid 6 and / or the heat conducting fluid 8 can be: a compound derived from methane (R000), a compound derived from ethane (R100), a compound derived from propane (R200), a compound derived from butane (R300), a zeotropic mixture (R400), an azeotropic mixture (R500), a mixture containing saturated hydrocarbons (R600), a mixture containing inorganic compounds with molar mass lower than 100 (R700) a mixture containing organic compounds with molar mass higher than 100 (R800).

[0133] According to a feature common to the main devised embodiments, said heat accumulator 4 is substantially solid and rigid, and it is made substantially of metallic material, preferably of ferrous material, more preferably of stainless steel, for example AISI 304, or of non-ferrous material, and it is configured to store heat for specific heat properties of said metallic material. The heat accumulator can be implemented with a set of granular elements, optionally metallic, preferably ferrous or non-ferrous. Such granular elements can all have a substantially same size, or on the contrary they can have different sizes. Such granular elements are enclosed in one single casing.

[0134] The heat accumulator 4 is further fastened suitably inside the main cavity 3 and then it is placed in a predefined and specific position inside it, lying spaced apart from the walls of the casing 2.

[0135] Although this should not be understood in a limiting manner, said heat accumulator 4 is configured to reach a temperature at least equal to 300°C, preferably at least equal to 400°C, still more preferably at least equal to 500°C or to 600°C or to 1000°C.

[0136] The device 1 , the present disclosure relates to, is configured to bring said heat exchange fluid 6 at a temperature at least equal to 90°C, or at least equal to 150°C, or at least equal to 300°C, or at least equal to 450°C.

[0137] Several practical forms can be actuated to implement the heat exchanger 5. However, it preferably comprises a bent duct, in particular implementing a serpentine arranged on a plane or assuming a substantially three-dimensional shape developing along at least a first and a second direction substantially orthogonal to each other.

[0138] The duct is configured to allow a flow of said heat exchange fluid 6.

[0139] The heat exchanger 5 comprises a first and a second terminal 5i, 5o. The two terminals 5i, 5o are respectively configured to be connected with a thermal user 100, positioned outside said device 1 and / or in remote position with respect to said device 1 and in use subtracting heat from said heat exchange fluid 6.

[0140] Non-limiting examples of said thermal user 100 are traditional water heaters, industrial heaters, heaters for underground environments, air heaters, passive heaters with cooling fins.

[0141] The herein described embodiments of the device 1 do not provide the use of flames for heating the metallic mass which implements the heat accumulator 4. For this reason, the device 1 , the present disclosure relates to, can be used in closed environments, since it does not emit combustion products. The device 1 , the present disclosure relates to, allows to regulate extremely precisely the amount of heat introduced in the heat accumulator 4. Moreover, the device 1 is particularly quick in heating the heat accumulator 4.

[0142] The sizes of the device 1 and the amount of heat accumulable by the heat accumulator 4 are easily scalable, both in terms of design and in practice. Therefore, the herein described device 1 can be used for reduced domestic applications or, in greater scale, for industrial applications.

[0143] The device 1 , the present disclosure relates to, is an integrated device. In particular, said casing 2, said heat accumulator 4, said heat exchanger 5 and said power supply group or system 7 are assembled in one single structure, mutually constrained and can be moved, transported or installed as one single assembly. First preferred embodiment and its variants

[0144] Figure 1 and figure 2 are referred to. The first preferred embodiment implements a heating of the heat accumulator by electromagnetic induction. To this purpose, the power supply group or system 7 comprises a radio frequency inductor 9.

[0145] The radio frequency inductor 9 comprises a control circuit 9a and an induction coil 9c, which is arranged around the heat accumulator 4.

[0146] Preferably, in this embodiment said heat accumulator 4 comprises a metallic mass substantially implemented in one single bloc, in case perforated as illustrated in figure 1 . The holes are designated with numeral reference 4f. Figure 2 illustrates an embodiment similar to that of figure 1 , however where the heat accumulator is implemented by a plurality of juxtaposed metallic masses.

[0147] In particular, the holes of the heat accumulator 4 are aligned along a substantially horizontal direction and they allow the transit of the heat conducting fluid 8 even inside the metallic mass structure; this technical feature allow a greater uniformity of heat exchange.

[0148] As it appears clear from figure 2, the heat exchanger 5 is part of the induction coil 9c; it can be stated that the induction coil implements at least part of said heat exchanger 5. In fact, the heat exchanger 5 is made of electrically conductive metallic material and it is preferably implemented with a hollow copper duct. The copper allows the passage of the alternating electric current required to the electromagnetic induction on the heat accumulator 4, and it is an optimum heat conductor and then - due to its cavity - allows the passage of the heat exchange fluid 6. It is sufficient that a first and a second portion of the duct are powered by terminals of a radiofrequency generator. Such first and second portion not necessarily have to be the terminal portions of the duct, which - as represented in figure 2, extend beyond the radio frequency inductor 9 becoming real terminals of the heat exchanger 5 in which in use the heat exchange fluid 6 enters or outflows.

[0149] It is observed that the use of a hollow heat exchanger 5 as induction coil 9c does not involve negative effects at level of electromagnetic induction; in fact, due to the well known skin effect, the density of electric current in the central portions of a conductor decreases as the frequency increases. Therefore, the absence of material in the central portions of the duct does not determine significant detriment phenomena on the electrical efficiency of induction.

[0150] The herein described embodiment preferably comprises a thermal insulator 10, preferably substantially rigid and optionally made of ceramic material.

[0151] The ceramic material is used since it substantially does not interfere with the radiofrequency radiation on the metallic mass of the heat accumulator 4. Such material can be equivalently replaced by any additional material capable of allowing the passage of a radiofrequency electromagnetic radiation without substantial absorption and, at the same time, guaranteeing a suitable thermal insulation.

[0152] As it appears clear from figure 2, the thermal insulator 10 is arranged in the main cavity 3 at a predefined distance from the heat accumulator 4. The thermal insulator 10 surrounds, and in particular encloses, the heat accumulator 4 in an internal sub-cavity 3i of the main cavity; then, it results that the heat accumulator is arranged substantially inside the thermal insulator 10.

[0153] Preferably, but not limitedly, the thermal insulator 10 can be made of ceramic fibre (apt to resist to temperature typically up to 1400°C), or glass fibre, or rock wool, in particular compacted rock wool, aluminium silicate, refractory ceramic. High- temperature polyurethanes can also be used to implement the thermal insulator 10, since they can resist to temperature even higher than 500°C.

[0154] For particular applications the thermal insulator 10 can include silica aerogel, a material with three-dimensional porous structure of silica nanoparticles. Such silica aerogel can be included in a material of additional type, in particular robust type, since it is known that the silica aerogel is fragile.

[0155] The radio frequency inductor is arranged outside the thermal insulator 10. In particular, the induction coil 9c surrounds the thermal insulator 10 (it is then arranged outside the latter), which can act as support for the induction coil 9c itself. In the embodiment of figure 2, the thermal insulator 10 comprises a substantially box-like structure with parallelepiped or cubic shape, clearly non limiting, and it has front and rear side walls 10r which are removable, for inserting the heat accumulator 4.

[0156] The thermal insulator 10 is kept at a predefined distance from the casing 2; between the casing 2 and the thermal insulator 10 an external sub-cavity is implemented, and the induction coil 9c is arranged in said external sub-cavity.

[0157] In the embodiment illustrated in the enclosed figures, the induction coil 9c has a plurality of coils spaced apart between each other and aligned axially along a direction substantially parallel to a development direction of the heat accumulator 4. The presence of the thermal insulator 10, which as described is not required but only preferable, is given by the fact that through electromagnetic induction temperatures also near to, or even higher than, 1000°C can be generated on the metallic mass; since the duct of the heat exchanger 5 is preferably made of a metallic material comprising copper, the use of the thermal insulator 10 allows to avoid excessive heating of the heat exchanger 5 without compromising the capability of loading thermally the heat accumulator in very high way.

[0158] Clearly, the presence of the thermal insulator 10 may not be necessary if through suitable limited electromagnetic induction the heat accumulator 4 is brought to temperatures compatible to those of the heat exchanger 5, or if the material thereof the heat exchanger 5 is implemented is made compatible with the high temperatures reachable by the heat accumulator 4, although this could mean to impose higher costs for the production of the heat exchanger 5.

[0159] The casing 2 is made of a substantially rigid material and it has at least an internal wall made of a highly thermally reflecting material.

[0160] The casing 2 can have an external portion for example made of glass fibre or an additional substantially rigid material apt to implement a substantially thermally insulating and, simultaneously, light structure.

[0161] The remaining part of the radio frequency inductor 9 is arranged below the main cavity 3, and in an preferred embodiment it is placed outside the casing 2.

[0162] In use, the electric current collected by the power supply source 200 is suitably processed by the circuit of the radiofrequency generator to be fed to the induction coil 9c, which then induces heat inside the heat accumulator 4. In particular, if the power supply source 200 produces direct current, the radiofrequency generator will cause a transformation of said current from direct to alternating. The frequence of the current induced in the induction coil 9c could be varied, in particular translated, according to needs.

[0163] In particular, it will be the designer’s responsibility to proceed with a selection of a suitable power supply frequency of the induction coil 9c in relation to the type of material of which the heat accumulator 4 is made and in relation to the induction depth which can be reached for a determined frequency, in particular before, or after, the Curie point. As general rule, the induction heating of small components requires high working frequencies (>50 kHz), in order to heat by induction parts with bigger sizes a lower frequency is more effective.

[0164] Although this technical solution cannot be represented, optionally a fluid forced circulation device 14 can be present, configured to force a flow of the heat conducting fluid 8 inside the main cavity 3 and to favour a heat exchange between said heat accumulator 4 and said heat exchanger 5. The fluid forced circulation device 14 can be a fan (useful if the heat conducting fluid is a gas) or a pump (useful if the heat conducting fluid is a liquid or a gel).

[0165] The fluid forced circulation device 14 is an electrical fluid forced circulation device and is electrically connected to and operatively controlled by said power supply group or system 7.

[0166] The radio frequency inductor 9 can have an impedance adapting circuit, with the purpose of adapting the impedance of the induction coil 9c according to the working frequency of the radiofrequency generator; in this way it is possible to reduce the coupling losses and then to have a more effective energy transfer from the radio frequency inductor to the heat accumulator.

[0167] In particular the impedance adapting circuit can operate: before the power supply of the radio frequency inductor 9, and in particular before the power supply of the voltage inverter of the radio frequency inductor 9, in order to make that the impedance be adapted seen from the latter to the specific electrical features shown by the induction coil 9c; during the power supply of the radio frequency inductor 9, in order to adapt the impedance seen from the voltage inverter to the impedance of the induction coil 9c which varies depending upon the temperature assumed by it and by the heat accumulator 4. Then, the impedance adaptation can also occur in substantially real time.

[0168] Second preferred embodiment and variants thereof

[0169] Reference is made to figures 3 and 4. In the second embodiment the heating of the heat accumulator 4 takes place by Joule effect. The heating of the heat accumulator is made possible by the fact that the power supply group or system 7 comprises an electrical power supply circuit ending on said first and second electrical power supply terminal 7a, 7b and further comprises a first and a second contact terminal 7c, 7d respectively connected to a first portion and a second portion of said heat accumulator 4 and configured to make, in use, an electric current to flow inside said heat accumulator 4.

[0170] In an embodiment the heat accumulator 4, similarly to the first embodiment, can include a metallic mass substantially implemented in a single bloc, in case perforated. In this case it is sufficient that the first and the second electrical power supply terminal 7a, 7b are placed at a first and second portion of the mass of the heat accumulator 4, distant from each other, for example two opposite portions (for example, top left portion in the front section and bottom right portion in the rear section).

[0171] Preferably, however, as represented in figure 3, the heat accumulator 4 comprises a plurality of elements 4e coupled with each other, and in particular juxtaposed. Said elements 4e are made of said metallic material, optionally ferrous material.

[0172] Each element 4e of said plurality of elements 4e assumes a substantially planar shape and it is substantially in laminar form.

[0173] Each element 4e of said plurality of elements 4e is positioned near, and separated from, at least an additional element 4e of said plurality of elements 4e.

[0174] In the specific embodiment illustrated in the enclosed figures, the plurality of elements 4e are aligned or juxtaposed on substantially parallel planes, or planes tilted by an angle lower than 10°, preferably 8°, with respect to each other, and in particular are aligned along a direction substantially tilted, preferably orthogonal, to each one of said parallel planes.

[0175] The elements 4e are modular elements; the greater their number, the greater the overall size of the heat accumulator 4 becomes. If the elements 4e are all implemented in a same size, each one having its own (identical) heat capacity given by its own specific heat, the heat capacity obtainable as a whole for the heat accumulator 4 is easily adjustable and, in case, adaptable.

[0176] Moreover, through the above-described configuration, the overall structure assumed by the heat accumulator 4 is particularly complex but at the same time particularly compact.

[0177] Since the heating by Joule effect is function of the electrical resistance, the herein described embodiment preferably comprises a plurality of elements 4e connected in series. The in-series connection is so as to make the overall electrical resistance assumed by the plurality of elements 4e equal to the sum of the electrical resistances of each one thereof.

[0178] It is observed that the heating by Joule effect is obtained not only with power supply direct currents, but even with discontinuous currents and in particular alternating sinusoidal currents. In this case the heating is induced by the average power provided to the electrical load represented by the metallic mass, given by:

[0179] P = Veffleffcoscp

[0180] <p being the offset angle between voltage and current.

[0181] In such case, assumed that the plurality of elements 4e only comprises two elements, the first contact terminal 7c is electrically connected to a first element 4e of said plurality of elements 4e and said second contact terminal 7d is connected to a second element 4e (and more generally to the last element) of said plurality of elements 4e.

[0182] In order to maximize the resistance of each element 4e even along the plane on which it develops, each element 4e has substantially curved shape or detecting at least one, preferably a plurality of, “V” or “U” sequentially connected to each other at ends of their legs, so as to detect a curved path for said electric current, so as to maximize the electrical resistance encountered in said element 4e between its two end portions.

[0183] At the hollows of “V”s or “U”s there are notches 4k which advantageously allow a suitable transit of the heat conducting fluid 8 and which then optimize the heat transfer from each one of the elements 4e to the heat exchanger 5 even in absence of contact between these two elements.

[0184] As represented in figure 4, each element 4e comprises a first terminal portion 4b (left side) and a second terminal portion 4c (right side) respectively arranged on a first side and on a second side of said element 4e. The first side is opposite to the second side.

[0185] The peculiar configuration with which the elements 4e are connected in series is so that said first element 4e is directly electrically connected to said second element 4e at said first terminal portion 4b or, alternatively, at said second terminal portion 4c. Reference is made to figures 5, 6 and 7.

[0186] More precisely, one defined a first, a second, a third and a fourth element 4e: said first element 4e and said second element 4e are directly electrically connected at said first terminal portion 4b and insulated and separated at said second terminal portion 4c, said second element 4e and said third element 4e are directly electrically connected at said second terminal portion 4c and insulated and separated at said first terminal portion 4b, said third element 4e and said fourth element 4e are directly electrically connected at said first terminal portion 4b and insulated and separated at said second terminal portion 4c.

[0187] In a preferred but not limiting embodiment, the direct connection between the elements 4e is implemented by welding or gluing with suitable strongly electrically conductive adhesives.

[0188] The particular connection configuration is so that, by observing perspective^ the heat accumulator 4, the direction of the electric current can go from left to right in the first element 4e, and - due to the direct connection - from right to left in the second element 4e and then - due to the direct connection - again from left to right in the third element 4e and so on.

[0189] With the purpose of guaranteeing a suitable robustness to the set, in a not-limiting embodiment the device 1 comprises a plurality of spacers 11 , which are interposed between the elements 4e, and in particular between the first element 4e and the second element 4e. As represented in figure 4, the spacers 11 assume a substantially disc-like and / or planar shape. The spacers 11 are made of electrically insulating material, for example ceramic or bakelite or mica or micanite or glass, with the purpose of not compromising the previously mentioned series connection, even because they touch two contiguous elements 4e even in different positions with respect to the portion in which they are directly electrically connected.

[0190] The elements 4e comprise through-holes 12 and have insulators 13 positioned in said through-holes 12. The insulators 13 have planar and disc-like shape, but clearly such configuration is not to be meant as limiting.

[0191] The insulators 13 are electrically insulating, and they, too, can be made of material comprising for example ceramic or bakelite or mica or micanite or glass.

[0192] In an preferred embodiment, the insulators 13 are provided with a a service hole, preferably having circular shape.

[0193] Moreover, even the spacers 11 have respective service holes. Inside the service holes of the spacers 11 and of the insulators 13 tie rods 18 are inserted which are useful to make the structure formed by the plurality of elements 4e substantially compact and fixed and in particular to keep the plurality of elements 4e in a predefined positional relationship.

[0194] The Applicant observed that the above-described temperature intervals, to which the elements 4e can be brought due to the heating induced by the passage of electric current, is so as to determine a size variation of the elements 4e and consequently even of the holes of the same. To this purpose, the insulator 13 has a lower size than the size of the through-hole 12 of the element 4e (see gap G in figure 5).

[0195] The dimensional ratio between the size of the insulator 13 and the size of the through-hole 12 is so as to allow a compensation of a dimensional variation of said through-hole 12 as a function of a thermal expansion or contraction determined by the heating of the element 4e.

[0196] It is observed that the particular positional relationship of the elements 4e allows a transit of the heat conducting fluid 8 even in vertical direction, by favouring then a heat exchange due to the convection effect.

[0197] In an embodiment not illustrated in the enclosed figures, the heat exchanger 5 is directly positioned inside the main cavity 3, at a suitable distance from the plurality of elements 4e. The heat exchanger even in this case can comprise a hollow duct for example made of copper, or equivalent material with optimum heat conduction capability with the purpose of guaranteeing an optimum heat transfer towards the heat exchange fluid 6.

[0198] However, the preferred variant of the second embodiment provides the use of a thermal insulator 10 positioned in a predefined position with respect to the heat accumulator 4, and preferably substantially below said heat accumulator 4.

[0199] The features of the thermal insulator 10 have already been described and therefore are not repeated.

[0200] Since the heat accumulator is arranged between a first (minimum) quote and a second (maximum) quote, the thermal insulator 10 is arranged at a lower quote than said first quote and said second quote.

[0201] The thermal insulator 10, which preferably implements a supporting plane below the heat accumulator 4, defines a secondary cavity 3s distinct with respect to the main cavity 3 and open on the main cavity 3.

[0202] The heat conducting fluid 8 can transit from the main cavity 3 to the secondary cavity 3s to transfer heat to the heat exchanger 5. The thermal insulator 10 is connected to an internal wall of the casing 2 and implements a bottom wall of said main cavity 3.

[0203] In order to favour the transit of the heat conducting fluid 8, the thermal insulator 10 comprises at least a first heat exchange hole 10f, putting said main cavity 3 and said secondary cavity 3s in communication.

[0204] The heat exchange hole 10f can be positioned in a substantially lateral or peripheral position of said thermal insulator 10 or be positioned in a substantially central position of said thermal insulator 10.

[0205] The heat exchanger 5 is arranged in said secondary cavity 3s and in use receives heat from the heat accumulator 4 by the transit of heat conducting fluid 8 through the heat exchange hole 10f.

[0206] In particular, the thermal insulator 10, if observed from bottom, highlights a substantially recessed profile which allows to house inside thereof, preferably for a main part, the heat exchanger 5.

[0207] In figure 3 and in figure 4 a variant is illustrated wherein the thermal insulator 10 comprises a first heat exchange hole 10f and a second heat exchange hole 10f .

[0208] The first heat exchange hole 10f is arranged on a first side of said thermal insulator 10 and the second heat exchange hole 10f is arranged on a second side of said thermal insulator 10. Said first side is opposite to said second side.

[0209] The function of the thermal insulator 10 also in this case is that of allowing to avoid an excessive heating of the heat exchanger 5.

[0210] The second embodiment of the device 1 , the present disclosure relates to, preferably has a fluid forced circulation device 14, configured to force a flow of the heat conducting fluid 8 inside the main cavity 3 and inside the secondary cavity 3s, and to favour a heat exchange between said heat accumulator 4 and said heat exchanger 5. The fluid forced circulation device 14 can be a fan (useful if the heat conducting fluid is a gas) or a pump (useful if the heat conducting fluid is a liquid or a gel). The figure 4 illustrates a configuration wherein such fan is a tangential fan.

[0211] The fluid forced circulation device 14 is arranged at a lower quote than said first quote, or at a lower quote than said first quote and said second quote.

[0212] The fluid forced circulation device 14 is arranged substantially corresponding to said secondary cavity 3s and forces a flow of said heat conducting fluid 8 from said main cavity 3 to said secondary cavity 3s through said at least a first heat exchange hole 10f . The heat conducting fluid 8 transits from the secondary cavity 3s again towards the main cavity 3 through the second heat exchange hole 10f , after having yielded heat to the heat exchange fluid 6 flowing, in use, inside the heat exchanger 5.

[0213] The fluid forced circulation device 14 is an electrical fluid forced circulation device and it is electrically connected to and operatively controlled by said power supply group or system 7.

[0214] Preferably, but not limitedly, the power supply group or system 7 comprises a data processing unit 7a configured: to regulate automatically an electric current absorbed by said power supply source 7, and / or to impose a regulation of a flow of said heat exchange fluid 6 inside said heat exchanger 5, and / or to regulate automatically a rotation speed of said fluid forced circulation device 14.

[0215] Preferably the data processing unit is configured to regulate automatically said electric current absorbed by said power supply source 7 and said rotation speed of said fluid forced circulation device 14 jointly, and / or depending on each other, and / or in synergistic way.

[0216] Thanks to this aspect the control of heat ultimately yielded to the heat exchange fluid is adjusted in particularly effective and flexible way, since quick variations in needs for absorbing electric current can be compensated, in particular if the power supply source 200 is a solar cell or an electric solar panel, and / or thermal inertia of the metallic mass as a whole implementing the heat accumulator 4.

[0217] The data processing unit, or control unit, can be a processor of general purpose type specifically configured to perform one or more parts of the process detected in the present disclosure through the software or firmware program, or it can be an ASIC or dedicated processor or a FPGA, specifically programmed to perform at least part of the procedures of the herein described process.

[0218] The memory support can be not transitory and it can be internal or external to the processor, or control unit, or data processing unit, and - specifically - can be a memory geographically placed remotely with respect to the electronic processor. The memory support can also be physically divided into several portions, or in “cloud” form, and the software or firmware programme can be physically on, or provide, portions stored on memory portions geographically divided from each other.

[0219] In the light of the preceding description it appears clear that the device 1 implements an integrated module capable of implementing a transformation of said electrical power supply source 200 into a heat storage source and it is preferably of plug-and- play type; in fact it is sufficient to connect the terminals 5i, 5o of the heat accumulator 5 to a user and the electrical power supply terminals of the power supply group or system 7 to make available the operation of the herein described device.

[0220] The invention is not limited to the embodiments illustrated in the enclosed figures and for this reason the reference numbers and signs of the following claims are provided only with the purpose of increasing intelligibility of claims. The reference numbers and signs have no limiting nature.

[0221] At last, it is clear that to the object of the present disclosure additions, modifications or variants, obvious to a person skilled in the art, can be applied, without thereby leaving the protective scope provided by the enclosed claims.

Claims

CLAIMS1. An electrically powered heat storage device (1 ), comprising: a thermally insulating casing (2), defining at least a main cavity (3) in use closed and at least thermally insulated from an external environment; a heat accumulator (4) arranged in said main cavity (3) and apt to be heated by, through or by the effect of, an electric current; at least a heat exchanger (5), comprising a duct apt to allow the passage of a heat exchange fluid (6), the heat exchanger (5) being operatively connected to said heat accumulator (4), and being configured to receive heat from said heat accumulator (4) and to transfer said heat to said heat exchange fluid (6); a power supply group or system (7), comprising at least a first and a second electrical power supply terminal (7a, 7b), configured to be powered, in use, by an electrical power supply source (200), preferably by at least one among an electricity grid and / or electric generator, a photovoltaic cell or an electric solar panel, said power supply group or system (7) being operatively coupled to said heat accumulator (4) and being configured to determine a heating of said heat accumulator (4) when electrically powered by said power supply group or system (7).

2. The device according to claim 1 , wherein said main cavity (3) insulates a herein present gas from an external atmosphere, wherein said device (1 ) is configured and specifically intended to implement a module, in use electrically connected, and preferably removably electrically connectable, to said at least an electrical power supply source (200), preferably to said at least a photovoltaic cell or to said at least an electric solar panel,implementing a transformation of said electrical power supply source (200) into a heat storage source and / or is of plug-and-play type, said device (1 ) being an integrated device wherein said casing (2), said heat accumulator (4), said heat exchanger (5) and said power supply group or system (7) are assembled in one single structure, mutually constrained and which can be moved, transported or installed as a single assembly; and wherein said casing (2) contains a heat conducting fluid (8), wherein said heat exchanger (5) is arranged in position spaced apart from, and not in contact with, said heat accumulator (4), and wherein said heat conducting fluid (8) , in use, comes in contact with said heat accumulator (4) and with said heat exchanger (5) and transfers heat from said heat accumulator (4) to said heat exchanger (5); and wherein said heat exchange fluid (6) and / or said heat conducting fluid (8) is a liquid or a gas, and in particular comprises at least one among the following fluids: water, air, nitrogen, carbon dioxide, sodium, compound derived from methane, compound derived from ethane, compound derived from propane, compound derived from butane, a zeotropic mixture, an azeotropic mixture, a mixture containing saturated hydrocarbons, a mixture containing inorganic compounds with molar mass lower than 100 or a mixture containing organic compounds with molar mass higher than 100.

3. The device according to claim 1 or claim 2, wherein said heat accumulator (4) is substantially solid and / or rigid, and it is made substantially of metallic material, optionally of ferrous material and / or of non-ferrous material, and it is configured to store heat for specific heat properties of said metallic material, optionally of said ferrous material and wherein: said heat accumulator (4) comprises a metallic mass substantiallyimplemented in a single bloc, or said heat accumulator (4) comprises a plurality of elements (4e) coupled with each other, and in particular juxtaposed, said elements (4e) being made of said metallic material, optionally ferrous material; optionally wherein each element (4e) of said plurality of elements (4e) assumes a substantially planar and / or laminar shape, and / or is positioned near, and separated from, at least an additional element (4e) of said plurality of elements (4e), and / or wherein the plurality of elements (4e) are aligned or juxtaposed on substantially parallel planes, or planes tilted by an angle lower than 10°, preferably 8°, with respect to each other, and in particular are aligned along a direction substantially tilted, preferably orthogonal, to each one of said parallel planes, optionally wherein said metallic mass comprises at least a hole (4f) configured to allow the passage of said heat conducting fluid (8).

4. The device according to one or more of the preceding claims, wherein said heat exchanger (5) comprises a bent duct, preferably implementing a serpentine arranged on a plane or assuming a substantially three-dimensional shape developing along at least a first and a second direction substantially orthogonal to each other, and wherein said bent duct is configured to allow a flow of said heat exchange fluid (6); said heat exchanger (5) comprising a first and a second terminal (5i, 5o), respectively configured to be connected with a thermal user (100), positioned outside said device (1 ) and / or in remote position with respect to said device (1 ) and in use subtracting heat from said heat exchange fluid (6), and wherein said power supply group or system (7) comprises an electric regulator configured to regulate, preferably automatically, the heating and / or a temperatureof said heat accumulator (4) and / or to regulate, preferably automatically, a current absorption from said power supply source (200), preferably said at least a photovoltaic cell or said at least an electric solar panel, and wherein said heat accumulator (4) is configured to reach a temperature at least equal to 300°C, preferably at least equal to 400°C, still more preferably at least equal to 500°C or to 600°C or to 1000°C and / or wherein said device (1 ) is configured to bring said heat exchange fluid (6) at a temperature at least equal to 90°C, or at least equal to 150°C, or at least equal to 300°C, or at least equal to 450°C.

5. The device according to one or more of the preceding claims, wherein said heat exchanger (5) is part of, and / or is integrated in, said power supply group or system (7), wherein said power supply group or system (7) comprises a radio frequency inductor (9), and said radio frequency inductor (9) comprises an induction coil (9c) arranged around said heat accumulator (4), wherein said heat exchanger (5) is part of said induction coil (9c) and / or wherein said induction coil (9c) implements at least part of said heat exchanger (5).

6. The device according to claim 2, comprising at least a fluid forced circulation device (14), configured to force a flow of the heat conducting fluid (8) inside said main cavity (3) and to favour a heat exchange between said heat accumulator (4) and said heat exchanger (5); preferably wherein: said heat accumulator (4) is arranged at a first quote or lies between a first and a second quote, and said fluid forced circulation device (14) is arranged at a lower quote than said first quote, or at a lower quote than said first quote and than said second quote;preferably said fluid forced circulation device (14) comprising a fan or a pump.

7. The device according to one or more of the preceding claims, comprising a thermal insulator (10), preferably substantially stiff and optionally made of ceramic material, said thermal insulator (10) being arranged in said main cavity (3) and being positioned at a predefined distance with respect to said heat accumulator (4); wherein: said thermal insulator (10) surrounds at least partially said heat accumulator (4) and / or wherein said heat accumulator (4) is arranged substantially inside said thermal insulator (10), and wherein said radio frequency inductor (9) is arranged substantially outside said thermal insulator (10), or said thermal insulator (10) is positioned in a predefined position with respect to said heat accumulator (4) and preferably substantially below said heat accumulator (4), preferably at a lower quote than said first quote, or lower than said first quote and than said second quote, said thermal insulator (10) defining a secondary cavity (3s) distinct with respect to said main cavity (3) and opened on said main cavity (3); preferably said induction coil (9c) lying outside, and partially surrounding, said thermal insulator (10) and / or said thermal insulator (10) acting as support for said induction coil (9c) and / or said thermal insulator (10) being made of a material apt to allow a substantial passage of an electromagnetic radiation induced by said induction coil (9c).

8. The device according to claim 7, wherein said thermal insulator (10) is connected to an internal wall of said casing (2) and comprises at least a first heatexchange hole (10f), putting in communication said main cavity (3) and said secondary cavity (3s); and wherein said heat exchanger (5) is arranged in said secondary cavity (3s) and receives heat from said heat accumulator (4) through said at least a first heat exchange hole (1 Of); preferably said thermal insulator (10) comprising a first heat exchange hole (1 Of) and a second heat exchange hole (1 Of), said first heat exchange hole (1 Of) being arranged on a first side of said thermal insulator (10), said second heat exchange hole (1 Of) being arranged on a second side of said thermal insulator (10), said first side being preferably opposite to said second side, said thermal insulator (10) implementing a bottom wall of said main cavity (3); preferably wherein said fluid forced circulation device (14) is arranged substantially corresponding to said secondary cavity (3s) and forces a flow of said heat conducting fluid (8) from said main cavity (3) to said secondary cavity (3s) through said at least a first heat exchange hole (1 Of); preferably said fluid forced circulation device (14) being an electrical fluid forced circulation device and being electrically connected to and operatively controlled by said power supply group or system (7), preferably said power supply group or system (7) comprising a data processing unit (7a) configured: to regulate automatically an electric current absorbed by said power supply source (7), and / or to impose a regulation of flow of said heat exchange fluid (6) inside said heat exchanger (5), and / or to regulate automatically a rotation speed of said fluid forced circulationdevice (14); preferably wherein the data processing unit is configured to regulate automatically said electric current absorbed by said power supply source (7) and said rotation speed of said fluid forced circulation device (14) jointly, and / or depending on each other, and / or in synergistic way.

9. The device according to one or more of the preceding claims if depending on claim 3, wherein: said heat accumulator (4) is configured to be heated by Joule effect, wherein said power supply group or system (7) comprises an electrical power supply circuit ending on said first and second electrical power supply terminal (7a, 7b) and further comprises a first and a second contact terminal (7c, 7d) respectively connected to a first portion and a second portion of said heat accumulator (4) and configured to make, in use, an electric current to flow inside said heat accumulator (4), said plurality of elements (4e) are electrically connected in series, said first contact terminal (7c) is electrically connected to a first element (4e) of said plurality of elements (4e) and said second contact terminal (7d) is connected to a second element (4e) of said plurality of elements (4e), and wherein each element (4e) has substantially curved shape or detecting at least one, preferably a plurality of, “V” or “U” sequentially connected to each other at ends of their legs, so as to detect a curved path for said electric current, preferably so as to maximize the electrical resistance met in the said element (4e), wherein each element (4e) comprises a first terminal portion (4b) and a second terminal portion (4c) respectively arranged on a first side and on a second side of said element (4e), said first side being opposite to said second side,wherein said first element (4e) is directly electrically connected to said second element (4e) at said first terminal portion (4b) or, alternatively, at said second terminal portion (4c), and wherein, once defined a first, a second, a third and a fourth element (4e): said first element (4e) and said second element (4e) are directly electrically connected at said first terminal portion (4b) and insulated and separated at said second terminal portion (4c), said second element (4e) and said third element (4e) are directly electrically connected at said second terminal portion (4c) and insulated and separated at said first terminal portion (4b).

10. The device according to one or more of the preceding claims if depending on claim 3, comprising a plurality of spacers (11 ) at least interposed between said first element (4e) and said second element (4e), said spacers (11 ) having preferably disc-like and / or planar shape, and being electrically insulating; and / or wherein said element (4e) comprises at least a through-hole (12) and an insulator (13) arranged in said through-hole (12); said insulator (13) having a service hole and being electrically insulating, said insulator (13) having a lower size than the size of the through-hole (12) of the element (4e), a dimensional ratio between the size of the insulator (13) and the size of the through-hole (12) being such as to allow a compensation of a dimensional variation of said through-hole (12) as a function of a thermal expansion or contraction determined by the heating of the element (4e).

11. The device according to any one of the preceding claims, wherein said heat accumulator (4) is made substantially of ferrous material.

12. The device according to any one of the preceding claims, wherein said heat accumulator (4) is made of steel.

13. The device according to any one of the preceding claims, wherein said heat accumulator (4) is made of stainless steel.

Images