Thermal insulation device

Abstract

A thermal insulation device (1) comprises a multilayer main body (2) comprising in turn an infrared-transparent protective layer (3), a reflecting layer (5) and a photoactive layer (4) interposed between the two. The photoactive layer (4) is switchable between a first configuration configured to absorb an infrared radiation and a second configuration configured to generate an infrared radiation, while the reflecting layer (5) is configured to reflect towards the photoactive layer (4) the infrared radiation not absorbed by the photoactive layer or generated by the latter. The device (1) further comprises an inverter (6) connected, or adapted to be connected, to the photoactive layer (4) and to an external electrical network to transfer an electrical current generated by the photoactive layer (4) to the external electrical network, or to transfer to the photoactive layer (4) an external direct electrical current from the external electrical network.

Description

[0001] “THERMAL INSULATION DEVICE” DESCRIPTION

[0002] SCOPE OF APPLICATION

[0003] The present invention relates to a thermal insulation device.

[0004] In particular, the present invention relates to a thermal insulation device for the building and energy sector, for use in both the industrial and domestic areas.

[0005] PRIOR ART

[0006] Insulation systems are known, consisting of various types of insulating materials that blocks out infrared radiation.

[0007] Materials with a low thermal transmission coefficient are also known.

[0008] However, the Applicant has not found in existing thermal insulation systems a system capable of exploiting infrared radiation, e.g. from sunlight, to increase the insulation characteristics and improve the energy efficiency of the shielding.

[0009] In particular, the Applicant noted that the materials used to date for the construction of thermal insulation devices do not allow for the conversion and exploitation of infrared rays, which are therefore dispersed, effectively defining a waste of energy that could be exploited in a different way.

[0010] In this context, the technical task underlying the present invention is to propose a thermal insulation device which overcomes one or more of the drawbacks of the prior art mentioned above.

[0011] In particular, an object of the present invention is to make available a structurally simple thermal insulation device with high energy performance. A further object of the present invention is to propose a thermal insulation device that is capable of generating or absorbing electric current and heat.

[0012] SUMMARY OF THE INVENTION

[0013] The defined technical task and the specified objects are substantially achieved by a thermal insulation device, comprising the technical characteristics set forth in one or more of the appended claims.

[0014] In particular, the present invention provides a thermal insulation device comprising a multilayer main body comprising: a protective layer, a photoactive layer and a reflecting layer.

[0015] The protective layer is made of infrared-transparent material and an outer face of the protective layer defines an outer surface of the multilayer main body exposed in use to an external environment, e.g. exposed to the atmosphere.

[0016] In other words, the protective layer is configured to receive infrared radiation from an external environment by transmitting it without absorbing it.

[0017] The a photoactive layer is made of semiconductor material and is selectively switchable between a first operating configuration wherein the photoactive layer is configured to at least partially absorb infrared radiation transmitted through the protective layer and a second operating configuration wherein the photoactive layer is configured to generate infrared radiation by emitting it towards the protective layer.

[0018] The reflecting layer is made of infrared reflecting material configured to reflect towards the photoactive layer the infrared radiation transmitted by the protective layer possibly not absorbed by the photoactive layer and to reflect towards the photoactive layer the infrared radiation generated by the photoactive layer. In particular, an outer face of the reflecting layer defines an inner surface of the multilayer main body exposed in use to an internal environment, e.g. a room, opposite said external environment.

[0019] In particular, the photoactive layer is interposed between the protective layer and the reflecting layer. In other words, the photoactive layer is confined on opposite sides between the protective layer and the reflecting layer.

[0020] Advantageously, the device further comprises an inverter connected, or adapted to be connected, to the photoactive layer of the multilayer main body and to an external power grid in order to: - transfer an internal direct electric current generated by the photoactive layer, following the absorption of infrared radiation, to the external electric power grid, or

[0021] - transfer to the photoactive layer an external direct electric current from the external power grid so that the photoactive layer can emit infrared radiation.

[0022] In other words, the thermal insulation device according to the present invention defines an efficient thermal insulation system capable of generating or absorbing electric current and heat when necessary, effectively insulating the indoor environment from the outdoor environment by transferring continuous electric current generated by the photoactive layer to the inverter and in turn allowing infrared radiation to be emitted if the photoactive layer receives continuous electric current from the external power grid.

[0023] In particular, the multilayer main body is made up of at least three layers with specific functions to efficiently realise high-performance energy conversion.

[0024] In particular, the protective layer has the function of protecting the photoactive layer from external agents (e.g. atmospheric or accidental agents) and at the same time transmitting the incident infrared radiation. The protective layer is advantageously made of a material capable of receiving light radiation in the infrared range from the external environment and transferring the infrared rays incident on the outer face to the photoactive layer.

[0025] The protective layer is also capable of receiving light radiation in the infrared range from the photoactive layer and emitting the infrared rays transmitted by the second layer to the external environment.

[0026] Advantageously, the photoactive layer is made of a semiconductor material capable of producing or absorbing electric current by producing or absorbing infrared radiation, thus absorbing or dissipating heat. The term “photoactive layer” refers to a material layer characterised by photoelectric behaviour, which can therefore produce an electric current when stimulated by photons of specific wavelengths, in this case infrared.

[0027] The semiconductor material of which the photoactive layer is made has an internal gap between the valence band and the conduction band capable of absorbing or emitting photons in the infrared spectrum, as shown in the attached Figure 2.

[0028] Due to the physical characteristics of the semiconductor material of which the photoactive layer is made, in other words, the photoactive layer can receive light radiation in the infrared range and convert it into an electric current (which is fed into the external power grid via the inverter), or it can receive an electric current and thus emit infrared, i.e. heat.

[0029] In particular, the reflecting layer is made of material with reflective properties in the infrared spectrum, which is thus able to mirror the infrared rays coming from the photoactive layer, to reflect them back to the photoactive layer, thus preventing their transmission into the internal environment.

[0030] The dependent claims herein incorporated for reference, correspond to different embodiments of the invention.

[0031] Further characteristics and advantages of the present invention will appear more clearly from the indicative, and therefore non-limiting, description of a preferred but not exclusive embodiment of a thermal insulation device, as illustrated in the attached drawings.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 depicts an operating diagram of the thermal insulation device according to the present invention.

[0034] Figure 2 is a schematic characteristic diagram of the semiconductor material characteristic of the photoactive layer.

[0035] DETAILED DESCRIPTION With reference to the attached figures, 1 indicates a thermal insulation device as a whole, hereinafter simply device 1 .

[0036] The device 1 comprises a multilayer main body 2 comprising a protective layer 3, a photoactive layer 4 and a reflecting layer 5, in which the photoactive layer 4 is interposed between the protective layer 3 and the reflecting layer 5.

[0037] The protective layer 3 is made of infrared-transparent material and an outer face of the protective layer defines an outer surface 2’ of the multilayer main body 2 exposed in use to an external environment.

[0038] Preferably the protective layer 3 is made of glass or is a paint.

[0039] Preferably the protective layer 3 has an average thickness comprised between 1 mm and 10 mm, even more preferably 4 mm.

[0040] The photoactive layer 4 is made of semiconductor material and is selectively switchable between:

[0041] - a first operating configuration, wherein the photoactive layer 4 is configured to at least partially absorb infrared radiation transmitted through the protective layer 3, and

[0042] - a second operating configuration, wherein the photoactive layer 4 is configured to generate infrared radiation by emitting it towards the protective layer 3.

[0043] In other words, the semiconductor material can advantageously be employed both for use in the first operating configuration, in which it absorbs energy (in the form of infrared radiation) and transfers it (in the form of direct electric current), and for reverse use in the second operating configuration, in which it receives energy (in the form of direct electric current) and transfers it (in the form of infrared radiation).

[0044] Figure 2 shows the characteristic curve of the semiconductor material of the photoactive layer 4: the abscissa shows the radiation frequencies q (infrared IR, visible, ultraviolet UV) and the ordinate the transmission coefficient v. Preferably, the photoactive layer 4 has an average thickness comprised between 1 pm and 350 pm, preferably 250 pm.

[0045] Preferably the photoactive layer 4 is made of a semiconductor material comprising at least one or more of silicon, germanium and carbon. Advantageously, silicon (preferably amorphous silicon), germanium and carbon are materials that can have a gap in the infrared spectrum.

[0046] In particular, the semiconductor material is doped with phosphorus or zinc. Advantageously, doping with zinc or phosphorus, or another material with similar chemical / physical properties, makes it possible to generate quantum jumps equal to or less than the energy value of a photon in the infrared spectrum and thus enables efficient conversion of energy from infrared to DC, and vice versa.

[0047] The reflecting layer 5 is made of infrared-reflective material and is configured to:

[0048] - reflect towards the photoactive layer 4 the infrared radiation transmitted by the protective layer 3 that may not have been absorbed by the photoactive layer 4 (during the first operating configuration), and to

[0049] - reflect towards the photoactive layer 4 the infrared radiation generated by the photoactive layer 4 (during the second operating configuration).

[0050] In particular, an outer face of the reflecting layer 5 defines an inner surface 2” of the multilayer main body 2 exposed in use to an internal environment opposite the external environment.

[0051] Preferably, the reflecting layer 5 has an average thickness comprised between 10 pm and 10 mm, preferably 1 mm.

[0052] Preferably the reflecting layer 5 is made of glass or plastic material.

[0053] Preferably, the reflecting layer 5 can be made to reflect towards the internal environment, i.e. in the opposite direction to the photoactive layer 4, the infrared radiation incident on the inner surface 2” of the multilayer main body 2. Advantageously, therefore, the reflecting layer 5 is also able to thermally insulate the internal environment from the external environment to prevent any infrared radiation incident on the internal surface 2” from being scattered through the multilayer main body 2 and being transmitted to the external environment.

[0054] In particular, the outer face of the reflecting layer 5 (i.e. the face exposed to the internal environment) can be treated with a selective coating, not illustrated in the attached figures, capable of achieving such infrared shielding.

[0055] Advantageously, the device 1 further comprises an inverter 6 connected, or adapted to be connected, to the photoactive layer 4, i.e. to the semiconductor material, of the multilayer main body 2 and to an external power grid, not illustrated in the attached figures, in order to:

[0056] - transfer an internal direct electric current generated by the photoactive layer 4, following the absorption of infrared radiation, to the external electric power grid, or

[0057] - transfer to the photoactive layer 4 an external direct electric current from the external power grid so that the photoactive layer 4 can emit infrared radiation.

[0058] Preferably, the device 1 comprises at least one radiating element, not illustrated in the attached figures, at least partially integrated into the protective layer 3 or arranged at the outer face of the protective layer 3, configured to receive the infrared radiation generated by the photoactive layer 4 for transferring it to an external fluid, not illustrated in the attached figures.

[0059] For example, the radiating element may be a coil made of a material capable of absorbing the infrared radiation emitted by the photoactive layer 4 (as well as any radiation reflected by the reflecting layer 5) and transforming it into heat to vary the temperature of the external fluid, e.g. water, inside or outside the coil.

[0060] With reference to the embodiment illustrated in Figure 1 , preferably the multilayer main body 2 is made in slab form.

[0061] In other words, the multilayer main body 2 has the shape of a flat panel whereby the inner surface 2” and the outer surface 2” are substantially parallel to each other, so that the thickness of the multilayer main body 2, measured perpendicular to the outer surface 2’ and the inner surface 2”, is variable depending on the design requirements but in any case has a much lower value than the other two dimensions.

[0062] Preferably, the thickness of the multilayer main body 2 in slab form is comprised between 100 pm and 20 mm, even more preferably 10 mm.

[0063] However, in accordance with a possible alternative embodiment not illustrated in the attached figures, the multilayer main body 2 could be made with curved or irregular shapes, depending on the specific application.

[0064] In this regard, the creation of layers 3, 4, 5 of the multilayer main body 2 could take place using materials in powder form instead of using prepackaged materials in slab form, so that the shape of the layers 3, 4, 5 could be modelled according to the construction and design requirements, ensuring efficient operating versatility.

[0065] Preferably the photoactive layer 4 may comprise at least one element made of thermoelectric material, not shown in the attached figures, even more preferably a Peltier cell, configured to absorb heat from the reflective layer 5 generated by the energy absorbed and not converted into electricity or reflected and transfer it to the protective layer 3 or vice versa. Advantageously, the presence of an element made of thermoelectric material allows the outer surface 2’ of the multilayer main body 2 to be cooled, which could be useful in some application areas (such as agriculture) for the condensation of moisture in the air.

[0066] In accordance with the embodiment illustrated in Figure 1 , preferably the protective layer 3 is in direct contact with the photoactive layer 4 and the photoactive layer 4 is in direct contact with the reflecting layer 5, or, in accordance with an alternative embodiment of the present invention not illustrated in the attached figures, there is at least one gap between the layers 3, 4, 5, even more preferably filled with a gas, for example air or argon.

[0067] In other words, with reference to the embodiment illustrated in Figure 1 , the multilayer main body 2 is a three-layer main body consisting solely of the sequence: protective layer 3, photoactive layer 4 and reflecting layer 5, i.e. the layers 3, 4, 5 are respectively arranged in direct contact with the immediately adjacent layer.

[0068] Alternatively, according to a possible embodiment of the present invention not illustrated in the attached figures, preferably between the protective layer 3 and the photoactive layer 4 a gap is formed, and / or preferably between the photoactive layer 4 and the reflecting layer 5 a gap is formed. This makes it possible, for example, to create a double-glazing unit with additional characteristic functions that can be selected according to the specific application, which is useful, for example, for applications in the building industry for windows and doors.

[0069] Preferably at least one of the protective layer 3, the photoactive layer 4 and the reflecting layer 5 is made of material that is transparent to visible light.

[0070] Even more preferably, the protective layer 3, the photoactive layer 4 and the reflecting layer 5 are made of material that is transparent to visible light.

[0071] Advantageously, when the layers 3, 4, 5 of the multilayer main body 2 are all made of material that is transparent to visible light, the invention finds particular application for window and door frames, allowing a user to see through the multilayer main body 2 (from the indoor environment to the outdoor environment and / or vice versa).

[0072] The present invention achieves the proposed purposes, overcoming the drawbacks complained of in the prior art and providing the user with a thermal insulation device that is structurally simple, customisable, high- performance and highly versatile in use. In contrast to systems of the prior art, the insulation system proposed by the present invention is capable of isolating an indoor environment from an outdoor environment exposed to solar radiation by absorbing and transforming a fraction of the solar energy in the infrared spectrum incident on the device 1 into electricity, thereby increasing the insulating efficiency of the device 1 and at the same time generating direct electric current. The energy drawn from the infrared beams and transferred away from the device 1 (via the inverter 6) in the form of direct electric current cannot therefore be transmitted into the internal environment, making the system - to all intents and purposes - an excellent insulation system.

[0073] Alternatively, the proposed device 1 is capable of receiving continuous electric current to emit infrared rays for various applications, such as heating a radiating element placed at the protective layer (transparent to infrared rays).

[0074] The invention thus makes it possible to produce heat and electricity while overcoming the limitations of the prior art in that it is able to insulate by means not of a shield but by means of a device capable of performing a conversion between radiant energy and electrical energy in both directions.

Claims

CLAIMS1. Thermal insulation device (1 ) comprising a multilayer main body (2) comprising:- a protective layer (3) of infrared-transparent material, wherein an outer face of said protective layer (3) defines an outer surface (2’) of said multilayer main body (2) exposed in use to an external environment,- a photoactive layer (4) made of semiconductor material which is selectively switchable between a first operating configuration wherein said photoactive layer (2) is configured to at least partially absorb infrared radiation transmitted through said protective layer (3) and a second operating configuration wherein said photoactive layer (4) is configured to generate infrared radiation by emitting it towards said protective layer (3), and- a reflecting layer (5) made of infrared reflecting material configured to reflect towards the photoactive layer (4) the infrared radiation transmitted by said protective layer (3) possibly not absorbed by the photoactive layer (4), and to reflect towards the photoactive layer (4) the infrared radiation generated by the photoactive layer (4), wherein an outer face of the reflecting layer (5) defines an inner surface (2”) of said multilayer main body (2) exposed in use to an internal environment opposite said external environment; said photoactive layer (4) being interposed between said protective layer (3) and said reflecting layer (5); said device (1 ) further comprising an inverter (6) connected, or adapted to be connected, to said photoactive layer (4) of the multilayer main body (2) and to an external power grid in order to:- transfer an internal direct electric current generated by said photoactive layer (4), following the absorption of infrared radiation, to said external electric power grid, or- transfer to the photoactive layer (4) an external direct electric current from the external power grid so that said photoactive layer (4) can emit infrared radiation.

2. Device (1 ) according to claim 1 , wherein said protective layer (3) is made of glass or is a varnish.

3. Device (1 ) according to claim 1 , wherein:- said protective layer (3) has an average thickness comprised between 1 mm and 10 mm, preferably 4 mm;- said photoactive layer (4) has an average thickness comprised between 1 pm and 350 pm, preferably 250 pm;- said reflecting layer (5) has an average thickness comprised between 100 pm and 20 mm, preferably 10 mm.

4. Device (1 ) according to claim 1 , comprising at least one radiating element, at least partially integrated into the protective layer (3) or arranged at said outer face of said protective layer (3), configured to receive the infrared radiation generated by said photoactive layer (4) for transferring it to an external fluid.

5. Device (1 ) according to claim 1 , wherein the photoactive layer (4) is made of a semiconductor material comprising at least one or more of silicon, germanium and carbon; said semiconductor material being additionally doped with phosphorus or zinc.

6. Device (1 ) according to claim 1 , wherein said multilayer main body (2) is made in slab form.

7. Device (1 ) according to claim 1 , wherein said reflecting layer (5) is made of glass or plastic material.

8. Device (1 ) according to claim 1 , wherein said reflecting layer (5) is configured to reflect towards the internal environment infrared radiation incident on the inner surface (2”) of the multilayer main body (2).

9. Device (1 ) according to claim 1 , wherein said photoactive layer (4) comprises at least one element made of thermoelectric material, preferably a Peltier cell, configured to absorb heat from the reflecting layer (5) and transfer it to the protective layer (3) or vice versa.

10. Device (1 ) according to claim 1 , wherein the protective layer (3) is in direct contact with the photoactive layer (4) and the photoactive layer (4) is in direct contact with the reflecting layer (5), or there is at least one gap between the layers, preferably filled with a gas, for example air or argon.11 . Device (1 ) according to claim 1 , wherein at least one of said protective layer (3), said photoactive layer (4) and said reflecting layer (5) is made of material transparent to visible light, and wherein preferably said protective layer (3), said photoactive layer (4) and said reflecting layer (5) are made of material transparent to visible light.

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