Multiband intelligent radiation temperature control device

Abstract

The invention provides a multiband intelligent radiation temperature control device, which realizes multiband intelligent radiation temperature control through innovative design, and is characterized in that a first micro-unit and a second micro-unit with different characteristic lengths are adopted in an optical functional layer, and according to an electromagnetic resonance theory, the first micro-unit with the long characteristic length is matched with a far infrared band wavelength, and the second micro-unit with the long characteristic length is matched with a far infrared band wavelength; the far infrared radiance can be modulated along with the change of the external temperature, and the second micro-unit with the short characteristic length is adaptive to a middle infrared band to realize corresponding radiance modulation; meanwhile, large-area temperature control uniformity is guaranteed through array arrangement of the modulation areas, and environment adaptability is enhanced through combination of the protection layer and the optical function layer. Compared with a traditional single-band temperature control device, the design breaks through band limitation, achieves mid-infrared and far-infrared dual-band cooperative regulation and control, can respond to environment temperature changes in real time, improves the temperature control precision and dynamic performance, and effectively solves the problems that in the prior art, temperature control is not accurate in a complex environment, and the application scene is single.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radiation refrigeration, and in particular to a multi-band intelligent radiation temperature control device and a method for controlling the temperature of the same. BACKGROUND

[0002] For many years, researchers have been working on developing radiation refrigeration materials to reduce the temperature of objects by conducting energy to outer space, the most typical example being radiation refrigeration roof materials for reducing the energy consumption of air conditioning refrigeration of buildings. In order to maximize the radiation refrigeration efficiency of buildings, these materials generally have very low solar absorption and very high thermal infrared emissivity. However, these traditional radiation refrigeration materials still emit heat in low-temperature environments, causing overcooling of buildings in cold nights or winter, resulting in additional energy consumption of the heating system. In areas with large diurnal temperature differences or low average annual temperatures, this part of the additional energy consumption of the heating system may even offset the energy saved by the refrigeration system, which is not conducive to energy saving throughout the year.

[0003] In order to solve the problem of overcooling of radiation refrigeration materials at low temperatures, a radiation temperature control film was proposed and passed the field test in 2021. The radiation temperature control film integrates a thermal sensitive phase change material vanadium dioxide inside, and its thermal infrared emissivity can automatically follow the temperature change of the film: when the temperature of the film is higher than the phase change temperature of vanadium dioxide, the radiation temperature control film has high thermal infrared emissivity, playing a passive refrigeration role; and when the temperature of the film is lower than the phase change temperature of vanadium dioxide, the radiation temperature control film has low thermal infrared emissivity, playing a passive heating role. According to the calculation, in most temperate and subtropical regions of the world, the radiation temperature control film can save more energy than all existing building surface materials.

[0004] Currently, there are two bands that can be used for radiation refrigeration: the sky window (atmospheric window) located in the mid-infrared 8~13 microns, and the partial sky window (partial atmospheric window) located in the far-infrared 16~28 microns. However, the existing intelligent radiation temperature control device can only adjust the emissivity in the sky window of 8~13 microns in the mid-infrared due to the dependence on a single size of resonant structure (characteristic length), and it is difficult to adjust the emissivity of far-infrared light (a single structure cannot meet the dual-band resonance requirements at the same time), resulting in the failure of far-infrared emissivity regulation. SUMMARY

[0005] The present application aims to provide a multi-band intelligent radiation temperature control device to solve the technical problem that the existing radiation temperature control device is difficult to simultaneously modulate the mid-infrared emissivity and the far-infrared emissivity.

[0006] To solve the above technical problems, the application provides a multi-band intelligent radiation temperature control device, which comprises an optical functional layer and a protective layer arranged on the upper side of the optical functional layer, and the optical functional layer comprises a plurality of modulation areas arranged in an array, and a first micro-unit and a second micro-unit are arranged in each modulation area in a relative interval, and the characteristic length of the first micro-unit is greater than the characteristic length of the second micro-unit. The first micro-unit is used for modulating the far-infrared emissivity of the multi-band intelligent radiation temperature control device according to the change of the external temperature, and the second micro-unit is used for modulating the mid-infrared emissivity of the multi-band intelligent radiation temperature control device according to the change of the external temperature.

[0007] Preferably, the orthographic projection of each first micro-unit or second micro-unit on the protective layer is a polygon, and the minimum distance d1 between the vertices of two adjacent polygons with the same geometric size is less than the distance d2 between the midpoints of the edges of the two adjacent polygons with the same geometric size.

[0008] Preferably, the first micro-unit or the second micro-unit is provided with a through hole in the up-down direction, and the shape of the through hole is any one of a circle, an ellipse and a polygon.

[0009] Preferably, the thickness of the first micro-unit and the second micro-unit is 0.1 μm to 3 μm, and the polygon is any one of a triangle, a quadrilateral or a hexagon.

[0010] Preferably, the orthographic projection of the first micro-unit on the protective layer is a first equilateral triangle, the orthographic projection of the second micro-unit on the protective layer is a second equilateral triangle, and the side length of the first equilateral triangle is greater than the side length of the second equilateral triangle. In the same modulation area, the corresponding side of the second equilateral triangle is arranged in parallel with the corresponding side of the first equilateral triangle.

[0011] Preferably, the first micro-unit is provided with a first circular hole and three third circular holes, the second micro-unit is provided with a second circular hole, and the aperture of the first circular hole is greater than the aperture of the second circular hole. The center of the first circular hole coincides with the center of the first micro-unit, the center of the second circular hole coincides with the center of the second micro-unit, and the shortest distance from the first circular hole to any one of the third circular holes is the same.

[0012] Preferably, the side length of the first equilateral triangle is 8 μm to 15 μm, the side length of the second equilateral triangle is 4 μm to 6.5 μm, and the minimum included angle between the side of the first equilateral triangle or the side of the second equilateral triangle and the length direction of the optical functional layer is-15° to 15°.

[0013] Preferably, the material of the first micro-unit or the second micro-unit is pure-phase vanadium dioxide or doped vanadium dioxide, and the doping elements of the doped vanadium dioxide include at least one of tungsten, copper, chromium, gallium, aluminum, iron, titanium, niobium, molybdenum, rhenium, fluorine, carbon and hydrogen.

[0014] Preferably, the multi-band intelligent radiation temperature control device further comprises a reflective layer arranged on the lower side of the optical functional layer, and the material of the reflective layer includes at least one of a metal film, graphene, carbon nanotubes, metal nanowires, metal mesh, conductive polymers and low-emissivity glass, and the metal film includes at least one of aluminum, iron, copper, silver, gold, chromium, nickel, platinum, tin, titanium, indium tin oxide, zinc aluminum oxide and gallium-doped zinc oxide.

[0015] Preferably, the material of the protective layer includes at least one of polyethylene, colored polyethylene, ethylene-propylene-diene rubber, polytetrafluoroethylene, polymethylpentene, MXene, hafnium oxide, magnesium fluoride, barium fluoride and calcium fluoride.

[0016] The beneficial effects of the present application are: compared with the prior art, the present application provides a multi-band intelligent radiation temperature control device which realizes multi-band intelligent radiation temperature control through innovative design, and the core is that the first micro-unit and the second micro-unit with different characteristic lengths are used in the optical functional layer, according to the electromagnetic resonance theory, the first micro-unit with long characteristic length matches the far-infrared wave band, and can modulate the far-infrared emissivity with the change of external temperature, and the second micro-unit with short characteristic length adapts to the middle-infrared wave band to realize corresponding emissivity modulation; at the same time, the array arrangement of the modulation area ensures the uniformity of large-area temperature control, and the combination of the protective layer and the optical functional layer enhances the environmental adaptability. Compared with the traditional single-band temperature control device, this design breaks through the wave band limitation, realizes the synergistic regulation and control of the middle-infrared and far-infrared double wave bands, can respond to the change of environmental temperature in real time, improves the temperature control precision and dynamic performance, can be widely applied in the fields of aerospace, meteorological remote sensing, intelligent building, etc., and effectively solves the problems of inaccurate temperature control and single application scene of the prior art in complex environment. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A cross-sectional structure schematic diagram of the multi-band intelligent radiation temperature control device provided by the embodiment of the present application is shown in the figure; Figure 2 A top view of the optical functional layer in the multi-band intelligent radiation temperature control device provided by an embodiment of the present application is shown in the figure; Figure 3 A top view of the optical functional layer in the single-band intelligent radiation temperature control device provided by the comparative example is shown in the figure; Figure 4 A thermal infrared emissivity spectrum of the multi-band intelligent radiation temperature control device provided by the embodiment 1 of the present application under high temperature condition is shown in the figure; Figure 5The thermal infrared emissivity spectrum of the multi-band intelligent radiation temperature control device provided for the embodiment 1 of the present application under low temperature condition; Figure 6 The thermal infrared emissivity spectrum of the single-band intelligent radiation temperature control device provided for the comparative example 1 under high temperature condition; Figure 7 The thermal infrared emissivity spectrum of the single-band intelligent radiation temperature control device provided for the comparative example 1 under low temperature condition; Fig. 1 is a protective layer; 2 is an optical functional layer; 200 is a modulation area; 21 is a first micro unit; 211 is a first circular hole; 212 is a third circular hole; 22 is a second micro unit; 221 is a second circular hole; 221 is a second circular hole; 23 is a micro unit; 3 is a reflective layer. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0019] In view of the technical problem that the existing intelligent radiation temperature control device is difficult to simultaneously modulate the far infrared emissivity and the mid-infrared emissivity due to the dependence on a single size resonance structure, the present application introduces two characteristic lengths to realize the simultaneous cooperative control of the mid-infrared emissivity and the far infrared emissivity, so as to respond to the environmental temperature change in real time and improve the temperature control precision and dynamic performance.

[0020] Please refer to Figure 1 and Figure 2 , Figure 1 The cross-sectional structure schematic diagram of the multi-band intelligent radiation temperature control device provided for the embodiment of the present application; Figure 2 The top view of the optical functional layer in the multi-band intelligent radiation temperature control device provided for an embodiment of the present application; wherein the present application provides a multi-band intelligent radiation temperature control device, which comprises an optical functional layer and a protective layer 1 arranged on the upper side of the optical functional layer, the optical functional layer 2 comprises a plurality of modulation areas 200 arranged in an array, a first micro unit 21 and a second micro unit 22 are arranged in each modulation area 200, the characteristic length of the first micro unit 21 is greater than the characteristic length of the second micro unit 22; The first micro unit 21 is used to modulate the far infrared emissivity of the multi-band intelligent radiation temperature control device according to the change of the external temperature; and the second micro unit 22 is used to modulate the mid-infrared emissivity of the multi-band intelligent radiation temperature control device according to the change of the external temperature.

[0021] Specifically, due to the characteristic length of the first micro-unit 21 being greater than the characteristic length of the second micro-unit 22 (referring to the key geometric dimension in the first micro-unit 21 or the second micro-unit 22 that affects its response to a specific infrared waveband radiation), according to the electromagnetic resonance principle, the larger characteristic length matches the longer wavelength of the far infrared waveband, so that it can effectively modulate the far infrared emissivity according to the external temperature change, while the smaller characteristic length of the second micro-unit 22 matches the middle infrared waveband, realizing the accurate regulation of the middle infrared emissivity; the two work together to break through the limitations of traditional temperature control devices for single waveband adjustment, and realize the dynamic adjustment of the middle infrared and far infrared dual waveband emissivity. At the same time, the optical functional layer 2 is designed with an array arrangement of the modulation area 200, which ensures the uniformity and stability of the large-area temperature control of the device; and the setting of the protective layer 1 further enhances the environmental adaptability and durability of the device.

[0022] In the embodiment of the present application, the material of the first micro-unit 21 and the second micro-unit 22 is pure-phase vanadium dioxide or doped vanadium dioxide, and the doping elements of the doped vanadium dioxide include at least one of tungsten, copper, chromium, gallium, aluminum, iron, titanium, niobium, molybdenum, rhenium, fluorine, carbon and hydrogen.

[0023] It can be understood that the present application uses vanadium dioxide to make a thermal infrared emissivity regulation metamaterial, so that the change of the infrared optical complex refractive index of vanadium dioxide in the thermal sensitive phase change process can be utilized to change the thermal infrared emissivity of the multi-waveband intelligent radiation temperature control device in the 8 μm~13 μm waveband (middle infrared) and the 16 μm~28 μm waveband (far infrared). In a high-temperature environment, the vanadium dioxide inside the optical functional layer 2 is in a metal state, so that the optical functional layer 2 has the characteristic of high thermal infrared emissivity, achieving the effect of passive refrigeration; in a low-temperature environment, the vanadium dioxide inside the optical functional layer 2 is in an insulating state, so that the optical functional layer 2 has the characteristic of low thermal infrared emissivity, achieving the effect of passive warming. Since the phase change temperature of vanadium dioxide can be adjusted by the type and concentration of the doping elements, the refrigeration-warming mode transition temperature of the multi-waveband intelligent radiation temperature control device can be freely designed. The hollow pattern vanadium dioxide metamaterial has the advantages of high thermal infrared emissivity in the refrigeration mode, low thermal infrared emissivity in the warming mode, low solar absorption rate, and low vanadium dioxide usage, which helps to improve the passive temperature control performance of the multi-waveband intelligent radiation temperature control device and reduce the production cost.

[0024] In some embodiments of the present application, the atomic number of the doping element accounts for less than or equal to 20% of the atomic number of vanadium in vanadium dioxide. For example, the atomic number of the doping element accounts for 0.1% to 19.9%, 0.5% to 19.5%, 1% to 19%, 2% to 15%, 5% to 12%, 4% to 7%, etc. of the atomic number of vanadium in vanadium dioxide. The above-mentioned doping elements can be doped in vanadium dioxide according to the need to adjust the phase transition temperature of vanadium dioxide, and then the cooling-warming mode transition temperature of the multi-band intelligent radiation temperature control device can be adjusted according to the need to adapt to the needs of different regions or different applications, and different contents of the doping element can be doped according to the need.

[0025] The present application has the advantages of batch production, low cost, thermal infrared emissivity with temperature change, large thermal infrared emissivity modulation depth, and adjustable cooling-warming mode conversion temperature, etc. It can stably control the temperature of buildings, vehicles, clothing, spacecraft with zero power consumption, and reduce the operating energy consumption of the cooling and heating temperature control system.

[0026] In the embodiment of the present application, the orthographic projection of each first micro-unit 21 or second micro-unit 22 on the protective layer 1 is a polygon, and the minimum distance d1 between the vertices of two adjacent polygons with the same geometric size is less than the distance d2 between the midpoints of the edges of the two adjacent polygons with the same geometric size.

[0027] Specifically, since d1 < d2, the adjacent two micro-units form an "angle-to-angle" arrangement, and then the adjacent two micro-units with the same geometric size form a high-loss antenna structure due to the similar sharp discharge effect (a sharp tip with a very small local radius of curvature is formed at the corner, and according to Gauss theorem, the accumulation of electric charge at the sharp tip leads to the enhancement of electric field). Compared with the parallel conductive plate structure formed by the existing arrangement (for example, Comparative Example 1), the enhancement of electric field is realized, the enhanced electric field leads to higher electric field loss rate, thereby achieving higher thermal infrared emissivity under high temperature conditions (10-20℃ higher than the phase transition temperature of the thermoelectric phase change material), and achieving lower thermal infrared emissivity under low temperature conditions (10-20℃ lower than the phase transition temperature of the thermoelectric phase change material). The modulation depth of the thermal infrared emissivity is greatly improved, which helps to greatly reduce the total annual energy consumption of the cooling and heating temperature control system. In the embodiment of the present application, the first micro-unit 21 or the second micro-unit 22 is provided with a through hole in the up-down direction, and the shape of the through hole is any one of a circle, an ellipse, and a polygon.

[0028] Specifically, the arrangement of the through holes in the first micro-unit 21 or the second micro-unit 22 realizes another structure of the high-loss antenna, and different high-loss antenna structures exist in the array at the same time, and the enhancement of the electric field is realized at different wavelengths, and then the high thermal infrared emissivity can be realized in a larger wavelength range at high temperature. At the same time, the arrangement of the through holes reduces the coverage of the thermoelectric phase change material in the first micro-unit 21 or the second micro-unit 22, so that a lower thermal infrared emissivity is achieved at low temperature; in addition, the arrangement of the through holes saves the amount of thermoelectric phase change material and reduces the cost, which is more suitable for mass production.

[0029] In the embodiment of the present application, the thickness of the first micro-unit 21 and the second micro-unit 22 is 0.1 μm-3 μm; wherein the thickness of the first micro-unit 21 and the second micro-unit 22 can be 0.1 μm-2.9 μm, 0.5 μm-2.5 μm, 0.8 μm-2.3 μm, 1 μm-2 μm, 1.5 μm-2 μm, etc. It can be understood that the thickness of the first micro-unit 21 or the second micro-unit 22 is the size in the up-down direction, and the thickness is controlled in the above range, which is convenient for forming a high-loss antenna structure, realizing the enhancement of the electric field, realizing a stronger electric field enhancement effect with less amount of vanadium dioxide, the enhanced electric field leads to a higher electric field loss rate, thereby achieving a higher infrared absorption rate at high temperature.

[0030] In the embodiment of the present application, the polygon is any one of a triangle, a quadrilateral or a hexagon; the triangle, the quadrilateral or the hexagon is selected as the projection shape of the first micro-unit 21 or the second micro-unit 22 on the protective layer 1, which brings significant beneficial effects from the aspects of geometric structure, electromagnetic characteristics and actual application: from the geometric point of view, these polygons can be closely arranged into an array to reduce the gap and realize the uniformity of the device surface temperature control; in terms of electromagnetic characteristics, the regular and symmetrical structure is beneficial to form a stable high-loss antenna structure, especially when the adjacent polygons are arranged in an "angle-to-angle" manner, the tip is similar to the tip discharge effect, the electric field is enhanced, and the thermal infrared emissivity at high temperature is improved; and the internal angle and the side length of the triangle, the quadrilateral and the hexagon are clear, which is convenient for adjusting the included angle, the side length and other parameters to accurately control the electromagnetic resonance frequency of the micro-unit and optimize the modulation effect on the mid-infrared and far-infrared emissivity. In practical application, the regular shape of the polygon is suitable for roll-to-roll imprinting and other batch production processes, which reduces the production cost; and the polygon shape can be flexibly selected according to the needs of different fields such as building and aerospace, such as the honeycomb structure of the hexagon which can be used for weight reduction of spacecraft, and the quadrilateral which is convenient for surface fitting of building glass, thereby improving the applicability and universality of the device.

[0031] In the embodiments of the present application, the orthographic projection of the first micro-unit 21 on the protective layer 1 is a first equilateral triangle, the orthographic projection of the second micro-unit 22 on the protective layer 1 is a second equilateral triangle, the side length of the first equilateral triangle is greater than the side length of the second equilateral triangle, the side length of the first equilateral triangle is 8-15 μm, and the side length of the second equilateral triangle is 6.5 μm; in the same modulation area 200 (the period boundary of each modulation area 200 is preferably a parallelogram), the corresponding side of the second equilateral triangle is arranged in parallel with the corresponding side of the first equilateral triangle.

[0032] Specifically, the present application realizes the multi-dimensional beneficial effects by designing the first micro-unit 21 and the second micro-unit 22 as equilateral triangles with different side lengths and arranging the corresponding sides in parallel, and adopting a parallelogram as the period boundary of the modulation area 200: based on the electromagnetic resonance theory, the large side length (such as 8-15 μm) of the first equilateral triangle meets the half-wave resonance condition (L~λ / 2) with the far-infrared waveband (16-28 μm), and the small side length (such as 4-6.5 μm) of the second equilateral triangle is suitable for the mid-infrared (8-13 μm), the parallel arrangement of the sides makes the surface current directions of the two consistent, enhances the co-polarized electromagnetic response, and avoids the waveband coupling interference; the parallelogram period boundary ensures that the structure is regularly repeated in the x-y plane, meets the phase matching condition of the Floquet theorem, makes the phase difference constant when the electromagnetic wave propagates in the array, and improves the uniformity (fluctuation <±2%) of the device in-plane emissivity; the design forms a high-loss antenna structure through the “angle-to-angle” arrangement, the electric field enhancement effect at the sharp end makes the far-infrared and mid-infrared emissivity at high temperature increase by more than 30% respectively, the modulation depth reaches 0.7-0.9, and at the same time, the parallelogram boundary optimizes the preparation process, adapts to the roll-to-roll imprinting technology, and reduces the production cost by 50% compared with the traditional scheme, which can be widely applied to spacecraft thermal management, building energy saving and other scenes, and realizes wide-band temperature control and energy consumption optimization.

[0033] In some embodiments of the present application, the sides of the plurality of first equilateral triangles or the sides of the plurality of second equilateral triangles are arranged in the length direction and the width direction of the optical functional layer 2 to form a two-dimensional triangular lattice with two different feature sizes. The two-dimensional triangular lattice is a lattice formed by periodically and closely arranging equilateral triangles. Specifically, the minimum angle between the edge of the first equilateral triangle or the edge of the second equilateral triangle and the length direction of the optical functional layer 2 is -15°-15°. For example, the minimum angle a between the edge of the first equilateral triangle or the edge of the second equilateral triangle and the length direction of the optical functional layer 2 can be -15°-12°, -9°-9°, -5°-5°, -2°-2°, etc. Specifically, by controlling the minimum angle between the edge of the first equilateral triangle or the edge of the second equilateral triangle and the length direction of the optical functional layer 2 within the above range, it is beneficial to form an "angle-to-angle" arrangement mode of the two adjacent first micro units 21 or the two adjacent second micro units 22, and the first micro unit 21 or the second micro unit 22 is provided with a through hole in the up-down direction to form a hollow structure, thereby forming a high-loss antenna structure. Compared with the parallel conductive plate structure formed by the existing arrangement mode, the electric field is enhanced, the electric field enhancement effect is achieved with less vanadium dioxide, the enhanced electric field leads to higher electric field loss rate, and thus higher infrared absorption rate is achieved under high temperature.

[0034] In the embodiment of the application, the first micro unit 21 is provided with a first circular hole 211 and three third circular holes 212, and the second micro unit 22 is provided with a second circular hole 221. The aperture (R1) of the first circular hole 211 is greater than the aperture (R2) of the second circular hole 221, and the aperture (R2) of the second circular hole 221 is greater than the aperture (R3) of the third circular hole 212, wherein 0.5 μm≤R3<R2<R1≤6 μm. The center of the first circular hole 211 coincides with the center of the first micro unit 21, and the center of the second circular hole 221 coincides with the center of the second micro unit 22. The shortest distance between the first circular hole 211 and any one of the third circular holes 212 is the same.

[0035] Specifically, since the first circular hole 211 aperture R1 (>R2) is size-matched with the far-infrared waveband wavelength, the second circular hole 221 aperture R2 is adapted to the mid-infrared waveband, and the three equidistant third circular holes 212 (R3<R2) form a "large hole-small hole" array with the first circular hole 211, the equidistant layout (consistent shortest distance) synchronizes the surface current phase in the far-infrared waveband, and the Floquet theorem periodic boundary condition enhances the coherence; the structure realizes far-infrared and mid-infrared waveband decoupling regulation by using the aperture gradient (0.5 μm≤R3<R2<R1≤6 μm), and the tip electric field enhancement effect (similar to high-loss antenna) caused by the curvature of the hole edge makes the far-infrared emissivity under high temperature increase by 80%, and the mid-infrared increase by 30%, and the modulation depth reaches 0.6 and 0.8 respectively; the hollow design reduces the amount of phase change material by 50%, adapts to the roll-to-roll imprinting process (aperture error<0.3 μm), reduces the cost by 50% compared with the traditional scheme, and can be widely applied to spacecraft thermal management and building energy saving scenes to realize wide-band temperature control and energy consumption optimization.

[0036] In some embodiments of the present application, the multi-band smart radiation temperature control device further comprises a reflective layer 3 disposed under the optical functional layer 2, the reflective layer 3 having high reflectivity in the mid-infrared waveband of 8 μm~13 μm and the far-infrared waveband of 16 μm~28 μm.

[0037] Specifically, the material of the reflective layer 3 comprises at least one of aluminum, silver, gold, chromium, nickel, platinum, tin and titanium, and the multi-band smart radiation temperature control device with the reflective layer 3 containing the above-mentioned material is suitable for being attached to the surface of any object, such as a building, a vehicle, a garment, a spacecraft, etc., and can stably control the temperature of the building, the vehicle, the garment, the spacecraft, etc. with zero power consumption and reduce the operation energy consumption of the temperature control system.

[0038] Under low temperature condition, W x V 1-x O2(W represents the above-mentioned doped elements) is in the infrared transparent semiconductor phase, at this time, the multi-band smart radiation temperature control device is similar to the mirror surface formed by the reflective layer 3 and has very low infrared absorption rate. According to the Kirchhoff's law of infrared radiation, the multi-band smart radiation temperature control device has very low thermal infrared emissivity in this state. When the temperature of the multi-band smart radiation temperature control device is higher than the phase transition temperature of W x V 1-x O2, W x V 1-x O2 is in the high-dissipation metal phase, which leads to strong impedance mismatch between W x V 1-x O2 and the protective layer 1, and forms a high-dissipation optical antenna with the adjacent W x V 1-x O2 unit. When the incident infrared light contacts the W x V 1-x O2 array, evanescent waves are formed on the sidewalls of the W x V 1-x O2 units, resulting in strong infrared absorption. According to the Kirchhoff's law of infrared radiation, the multi-band smart radiation temperature control device has very high thermal infrared emissivity in this state.

[0039] In some embodiments of the present application, the multi-band intelligent radiation temperature control device further comprises a reflective layer 3 disposed on the lower side of the optical functional layer 2, and the material of the reflective layer 3 comprises at least one of indium tin oxide, zinc aluminum oxide, gallium-doped zinc oxide, graphene, carbon nanotube, metal nanowire, metal mesh, conductive polymer and low-emissivity glass. The reflective layer 3 is an infrared reflective layer 3, which has high transmittance at 0.4 μm~0.76 μm, and high reflectivity at 8 μm~13 μm mid-infrared waveband and 16 μm~28 μm far-infrared waveband. The multi-band intelligent radiation temperature control device with the reflective layer 3 containing the above-mentioned materials is suitable for being attached to the window of a building or a vehicle, and plays a passive radiation temperature control role, has the advantages of low cost, mass production, thermal infrared emissivity changing with temperature, adjustable refrigeration-warmth mode conversion temperature, high visible light transmittance, etc., and can stabilize the temperature of the building or the vehicle with zero power consumption and reduce the operation energy consumption of the temperature control system.

[0040] In some embodiments of the present application, the low-emissivity glass meets the national standard “Coated Glass Part 2: Low-Emissivity Coated Glass” (GB / T 18915.2).

[0041] It can be understood that when the multi-band intelligent radiation temperature control device of the present application is attached to a glass replacement (such as low-emissivity glass) of a film system product composed of indium tin oxide (i.e. ITO film), zinc aluminum oxide, gallium-doped zinc oxide, graphene, carbon nanotube, metal nanowire, metal mesh, conductive polymer or coated with multiple layers of metal or other compounds (such as ITO film), the multi-band intelligent radiation temperature control device can be without the reflective layer 3, and the indium tin oxide, zinc aluminum oxide, gallium-doped zinc oxide, graphene, carbon nanotube, metal nanowire, metal mesh, conductive polymer and low-emissivity glass can act as the reflective layer 3, which can further reduce the cost.

[0042] In some embodiments of the present application, the protective layer 1 has high transmittance at 8 μm~13 μm mid-infrared waveband and 16 μm~28 μm far-infrared waveband.

[0043] Specifically, the material of the protective layer 1 includes a permeable material, and the permeable material includes at least one of polyethylene, colored polyethylene, ethylene propylene terpolymer, polytetrafluoroethylene, polymethylpentene, MXene, hafnium oxide, magnesium fluoride, barium fluoride and calcium fluoride. The above protective layer 1 can make the infrared light in the 8-13 μm and 16-28 μm wave bands enter the optical functional layer 2, which is conducive to the formation of the "angle-to-angle" arrangement mode of the adjacent two first micro units 21 or the adjacent two second micro units 22, and the first micro unit 21 or the second micro unit 22 is provided with a through hole in the up-down direction to form a hollow structure, forming a high-loss antenna structure. Compared with the parallel conductive plate structure formed by the existing arrangement mode, the electric field is enhanced, the use amount of vanadium dioxide is reduced, the electric field enhancement effect is stronger, the enhanced electric field leads to a higher electric field loss rate, thereby achieving a higher infrared absorption rate under high temperature. At the same time, there are many different high-loss antenna structures in the array, so that different wavelengths of infrared light can be absorbed, and therefore, compared with the prior art, the present application can realize high thermal infrared emissivity in a larger wavelength range under high temperature. Research shows that in the wavelength range of 8-13 μm and 16-28 μm, the high-temperature thermal infrared emissivity of the multi-band intelligent radiation temperature control device of the present application is increased by more than 30%, and the low-temperature thermal infrared emissivity is reduced by more than 30%, which helps to greatly reduce the total annual energy consumption of the cold and warm temperature control system.

[0044] Referring to Figure 1 , the protective layer 1 has high transmittance in the 8-13 μm wave band, and the constituent material is at least one of polyethylene, colored polyethylene, ethylene propylene terpolymer, polytetrafluoroethylene, polymethylpentene, MXene, hafnium oxide, magnesium fluoride, barium fluoride and calcium fluoride, and has high transmittance in the 8-13 μm and 16-28 μm wave bands. The optical functional layer 2 is formed by splicing unit structures with different characteristic lengths in each modulation area 200 in an array form on the film, each unit structure includes a large and small hollow triangular pattern, and the main material is vanadium dioxide or vanadium dioxide doped with at least one of chromium, tungsten, gallium, aluminum, iron, titanium, niobium, molybdenum, rhenium, fluorine and hydrogen. The reflective layer 3 has high reflectivity in the 8-13 μm and 16-28 μm wave bands. The optical functional layer 2 is embedded in the protective layer 1 and closely attached to the reflective layer 3.

[0045] In the embodiment of the present application, the preparation method of the above multi-band intelligent radiation temperature control device includes the following specific steps: S10, align the preheated protective film with the micro unit array (including the first micro unit 21 pattern and the second micro unit 22 pattern) convex plate, and press the pattern on the micro unit array convex plate onto the surface of the above film through a roll-to-roll printing device to form a protective layer 1 with a micro unit array recess.

[0046] Specifically, the S10 step further comprises: First, a protective film with a thickness of 5-200 μm is provided, which is composed of at least one of polyethylene, colored polyethylene, ethylene-propylene-diene rubber, polytetrafluoroethylene, polymethylpentene, MXene, hafnium oxide, magnesium fluoride, barium fluoride and calcium fluoride.

[0047] Second, the above protective film heated to 80-200 °C is aligned with a microcell array (including a first microcell 21 pattern and a second microcell 22 pattern) relief, and the pattern on the microcell array relief is imprinted on the surface of the above film at a speed of 0.1-50 cm / s through a roll-to-roll imprinting device. At this point, the above film with a microcell array pit on the surface forms the required protective layer 1.

[0048] S20, filling a thermotropic phase change material into the microcell array pit to form an optical functional layer 2.

[0049] Specifically, the S20 step further comprises: Vanadium dioxide nano-powder with a diameter of 0.01-1 μm is filled into the surface of the protective layer 1. The surface of the protective layer 1 has a microcell array pit. Then, the excess vanadium dioxide powder on the surface of the protective layer 1 is wiped off, leaving only the vanadium dioxide powder filled in the pit. At this point, the vanadium dioxide powder forms the required optical functional layer 2.

[0050] The optical functional layer 2 comprises a plurality of modulation regions 200 arranged in an array, each modulation region 200 is provided with a first microcell 21 and a second microcell 22 arranged at a relative interval, and the characteristic length of the first microcell 21 is greater than that of the second microcell 22.

[0051] Specifically, the orthographic projection of each first microcell 21 or second microcell 22 on the protective layer 1 is a polygon, the minimum distance d1 between the vertices of two adjacent polygons with the same geometric size is less than the distance d2 between the midpoints of the sides of the two adjacent polygons with the same geometric size, and the material of the first microcell 21 or the second microcell 22 comprises vanadium dioxide; the orthographic projection of the first microcell 21 on the protective layer 1 is a first equilateral triangle, and the orthographic projection of the second microcell 22 on the protective layer 1 is a second equilateral triangle; the side length of the first equilateral triangle is greater than that of the second equilateral triangle; in the same modulation region 200, the corresponding side of the second equilateral triangle is arranged in parallel with the corresponding side of the first equilateral triangle.

[0052] Specifically, the first micro unit 21 is provided with a first circular hole 211 and three third circular holes 212, and the second micro unit 22 is provided with a second circular hole 221, the aperture of the first circular hole 211 is larger than the aperture of the second circular hole 221, and the aperture of the second circular hole 221 is larger than the aperture of the third circular hole 212; the center of the first circular hole 211 coincides with the center of the first micro unit 21, and the center of the second circular hole 221 coincides with the center of the second micro unit 22; the shortest distance from the first circular hole 211 to any one of the third circular holes 212 is the same.

[0053] Therefore, the multi-band intelligent radiation control temperature device prepared by the application can realize greater infrared thermal radiation rate modulation depth in a wider wavelength range, 30% less energy loss at low temperature and 30% more energy output at high temperature than the prior art, the solar light absorption rate is reduced by about 50%, which is more suitable for use as a transparent coating and can be attached to the surface of glass, and the amount of vanadium dioxide is reduced by about 50%, which is more conducive to cost saving.

[0054] In the embodiment of the application, after the step S20 is completed, a reflective layer 3 is formed on the side of the protective layer 1 close to the optical functional layer 2, and the reflective layer 3 completely covers the optical functional layer 2.

[0055] In some embodiments of the application, the reflective layer 3 can be prepared by the following method: The protective layer 1 and the optical functional layer 2 composite film containing the vanadium dioxide micro unit array are stacked on the surface of the reflective layer 3 film, and the contact surface with the reflective layer 3 film is the side of the vanadium dioxide array. The material of the above-mentioned reflective layer 3 film is at least one of aluminum, silver, gold, chromium, nickel, platinum, tin, titanium, indium tin oxide, zinc aluminum oxide, gallium-doped zinc oxide, graphene, carbon nanotube, metal nanowire, metal mesh, conductive polymer and low-emissivity glass. At a temperature of 80℃-200℃, at a speed of 0.1cm / s-50cm / s, the stacked film is passed through a roll-to-roll lamination device, so that the side containing the vanadium dioxide array in the protective layer 1 and the optical functional layer 2 composite film is bonded with the aluminum film. The structure at this time is a three-layer structure as shown in the figure. Figure 1

[0056] In some other embodiments of the application, the reflective layer 3 can be prepared by the following method: ​The composite film of the protective layer 1 and the optical functional layer 2 containing the array of vanadium dioxide microcells is placed into a vacuum sputtering coating machine, and a 0.05-1 μm reflective layer 3 film is deposited on the surface of the composite film of the protective layer 1 and the optical functional layer 2 containing the array of vanadium dioxide in an argon environment at a power of 50-1000 W. The material of the reflective layer 3 film is at least one of aluminum, silver, gold, chromium, nickel, platinum, tin, titanium, indium tin oxide, zinc aluminum oxide, gallium-doped zinc oxide, graphene, carbon nanotube, metal nanowire, metal mesh, and conductive polymer.

[0057] The scheme of the present disclosure will be explained below in conjunction with examples. Those skilled in the art will understand that the examples below are only for illustration of the present disclosure and should not be regarded as limiting the scope of the present disclosure. If a specific technique or condition is not specified in the examples, the technique or condition described in the literature in the art or according to the product manual is used. If the manufacturer of the reagent or instrument is not specified, it is a conventional product that can be obtained commercially.

[0058] Example 1: 1. Material of the protective layer 1: polyethylene; Preparation of the protective layer 1: the material of the protective layer 1 is a polyethylene film with a thickness of 80 μm. The polyethylene film heated to 125°C is aligned with the microcell array relief, and the pattern on the microcell array relief is imprinted on the surface of the polyethylene film at a speed of about 0.5 cm / s through a roll-to-roll imprinting device. Thus, the polyethylene film with the microcell array pits on the surface forms the required protective layer 1.

[0059] 2. Material of the optical functional layer 2: vanadium dioxide; Preparation of the optical functional layer 2: vanadium dioxide nano-powder with a diameter of less than 0.2 μm is filled into the surface of the protective layer 1. The surface of the protective layer 1 has microcell array pits. Then, the excess vanadium dioxide powder on the surface of the protective layer 1 is removed, and only the vanadium dioxide powder filled into the pits is reserved. Thus, the vanadium dioxide powder forms the required optical functional layer 2.

[0060] The top view of the optical functional layer 2 is shown in FIG. 2. Figure 2 As shown in FIG. 2, the optical functional layer 2 includes a plurality of modulation regions 200 arranged in an array (the modulation regions 200 are rhombuses with a side length T of 15 μm at the boundary), and each modulation region 200 is provided with a first microcell 21 and a second microcell 22 arranged at a relative interval. The material of the first microcell 21 or the second microcell 22 includes vanadium dioxide, and the thickness of the first microcell 21 or the second microcell 22 is 1.5 μm.

[0061] Specifically, the orthographic projection of the first microcell 21 on the protective layer 1 is a first equilateral triangle with a side length of 12 μm. The first micro unit 21 is provided with a first circular hole 211 and three third circular holes 212, the hole diameter R1 of the first circular hole 211 is 2.5 μm, and the hole diameter R3 of the third circular hole 212 is 1.2 μm; the second micro unit 22 is a second equilateral triangle in the orthographic projection on the protective layer 1, and the side length is 5 μm; the second micro unit 22 is provided with a second circular hole 221, the hole diameter R2 of the first circular hole 211 is 2 μm, and the smallest angle between the side of the first equilateral triangle or the side of the second equilateral triangle and the length direction of the optical functional layer 2 is 0°.

[0062] 3. The material of the reflective layer 3 is aluminum. The reflective layer 3 is installed by stacking the above optical functional layer 2 and the protective layer 1 on the surface of the aluminum film and ensuring that the contact surface with the aluminum film is the side of the optical functional layer 2. At a temperature of 115°C, the stacked film is passed through a roll-to-roll lamination device at a speed of 3 cm / s, and the side of the composite film of the protective layer 1 and the optical functional layer 2 containing the vanadium dioxide array is bonded to the aluminum film.

[0063] Comparative Example 1 Comparative Example 1 provides a single-band intelligent radiation temperature control device, which includes an optical functional layer 2 and a protective layer arranged on the upper side of the optical functional layer 2, and the optical functional layer 2 includes a plurality of micro units 23 arranged in an array, and the micro units 23 are used to modulate the thermal infrared emissivity of the single-band intelligent radiation temperature control device according to the change of the external temperature, and the projection of each micro unit 23 on the protective layer 1 is a square.

[0064] Specifically, the preparation method of the single-band intelligent radiation temperature control device of Comparative Example 1 is as follows: 1. The material of the protective layer is polyethylene. Preparation of the protective layer: the protective layer material is a polyethylene film with a thickness of 12 μm. The polyethylene film heated to 110°C is aligned with the micro unit array relief, and the pattern on the micro unit array relief is imprinted on the surface of the polyethylene film at a speed of 0.2 cm / s through a roll-to-roll imprinting device. At this time, the polyethylene film with the micro unit array pits on the surface forms the required protective layer.

[0065] 2. The material of the optical functional layer 2 is vanadium dioxide. Preparation of the optical functional layer 2: 0.3 μm diameter vanadium dioxide nano powder is filled into the surface of the protective layer. The surface of the protective layer has a micro unit array pit. Then, the excess vanadium dioxide powder on the surface of the protective layer is removed, and only the vanadium dioxide powder filled in the pit is reserved. At this time, the vanadium dioxide powder forms the required optical functional layer 2.

[0066] The top view of the optical functional layer 2 is as shown in FIG. 2. Figure 3As shown, the projection of the microcell of the comparative example 1 on the protective layer is a square, no through hole, the side length of the square is 5 μm, the thickness of each microcell is 1.5 μm, the angle between any one side of the square and the length direction of the optical functional layer 2 is 0° or 90°, and the period of the microcell array structure (the shortest distance between two corresponding vertices of adjacent two microcells) is 5 μm.

[0067] 3. The material of the reflective layer: aluminum; The reflective layer is added: the optical functional layer 2 and the protective layer are stacked on the surface of the aluminum film, and the contact surface with the aluminum film is the side of the optical functional layer 2. At a temperature of 110°C, the stacked film is passed through a roll-to-roll lamination device at a speed of 0.2 cm / s, and the side of the composite film containing the vanadium dioxide array in the protective layer and the optical functional layer 2 is bonded to the aluminum film.

[0068] In the embodiment of the present application, finite element method is used to analyze the electromagnetism of the example 1 and the comparative example 1, and the electromagnetic parameters of the two are obtained respectively as Figures 4-7 . Figure 4 The thermal infrared emissivity spectrum of the multi-band intelligent radiation temperature control device provided by the example 1 of the present application under high temperature condition; Figure 5 The thermal infrared emissivity spectrum of the multi-band intelligent radiation temperature control device provided by the example 1 of the present application under low temperature condition; Figure 6 The thermal infrared emissivity spectrum of the single-band intelligent radiation temperature control device provided by the comparative example 1 under high temperature condition; Figure 7 The thermal infrared emissivity spectrum of the single-band intelligent radiation temperature control device provided by the comparative example 1 under low temperature condition.

[0069] Comparing Figure 4 and Figure 6 , it can be seen that the thermal infrared emissivity of the multi-band intelligent radiation temperature control device of the example 1 of the present application in the mid-infrared waveband of 8 μm~13 μm ranges from 0.58 to 0.95, which is higher than the 0.52~0.77 of the single-band device of the comparative example 1, the lower limit is increased by 11.5%, the upper limit is increased by 23.4%, and the average value is increased by 37%; in the far-infrared waveband of 16 μm~28 μm, the emissivity is 0.32~0.98, which is higher than the 0.23~0.38 of the comparative example 1, the lower limit is increased by 39.1%, the upper limit is increased by 157.9%, and the average value is increased by 66%.

[0070] Comparing Figure 5 and Figure 7It can be known by comparison that the multi-band intelligent radiation temperature control device of the embodiment 1 of the present application exhibits better thermal infrared emissivity regulation capability in a low temperature environment: in the middle infrared waveband of 8 μm~13 μm, the emissivity range thereof is 0.22~0.68, although the lower limit is flat with that of the comparative example 1 (0.22~0.55), but the upper limit is increased by 23.6%, and the comprehensive average value is increased by 23%; in the far infrared waveband of 16 μm~28 μm, the emissivity is as low as 0.04~0.18, which is lower than 0.05~0.16 of the comparative example 1 by 20%, the upper limit is increased by 12.5%, and the comprehensive average value is increased by 31%.

[0071] In summary, compared with the prior art, the present application has the following beneficial effects: the present application provides a multi-band intelligent radiation temperature control device and a preparation method thereof, the optical functional layer 2 of the multi-band intelligent radiation temperature control device adopts the first micro unit 21 and the second micro unit 22 with different characteristic lengths, according to the electromagnetic resonance theory, the first micro unit 21 with a long characteristic length matches the far infrared waveband, and can modulate the far infrared emissivity with the change of the external temperature, and the second micro unit 22 with a short characteristic length adapts to the middle infrared waveband to realize corresponding emissivity modulation; at the same time, the array arrangement of the modulation area 200 ensures the uniformity of large-area temperature control, and the combination of the protective layer and the optical functional layer 2 enhances the environmental adaptability. Compared with the traditional single-band temperature control device, this design breaks through the waveband limitation, realizes the synergistic regulation of the middle infrared and far infrared double wavebands, can respond to the change of the environmental temperature in real time, improves the temperature control precision and dynamic performance, can be widely applied in the fields of aerospace, meteorological remote sensing, intelligent building, etc., and effectively solves the problems of inaccurate temperature control and single application scene of the prior art in a complex environment.

[0072] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own emphasis, and the description not described in detail in individual embodiments can be referred to the description in other embodiments.

[0073] The above embodiments only express the implementation of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A multi-band intelligent radiation temperature control device, characterized in that, It includes an optical functional layer and a protective layer disposed on the upper side of the optical functional layer. The optical functional layer includes a plurality of modulation regions arranged in an array. Each modulation region is provided with a first micro-unit and a second micro-unit arranged at relative intervals. The feature length of the first micro-unit is greater than the feature length of the second micro-unit. The first micro-unit is used to modulate the far-infrared emissivity of the multi-band intelligent radiation temperature control device according to changes in the external temperature; the second micro-unit is used to modulate the mid-infrared emissivity of the multi-band intelligent radiation temperature control device according to changes in the external temperature.

2. The multi-band intelligent radiation temperature control device according to claim 1, characterized in that, Each of the first micro-units or the second micro-units has an orthographic projection on the protective layer that is a polygon. The minimum distance d1 between the vertices of two adjacent polygons with the same geometric dimensions is less than the distance d2 between the midpoints of the sides of two adjacent polygons with the same geometric dimensions.

3. The multi-band intelligent radiation temperature control device according to claim 1, characterized in that, The first micro-unit or the second micro-unit has a through hole extending vertically, and the shape of the through hole is any one of a circle, an ellipse, or a polygon.

4. The multi-band intelligent radiation temperature control device according to any one of claims 2 to 3, characterized in that, The thickness of both the first micro-unit and the second micro-unit is 0.1μm to 3μm; the polygon is any one of a triangle, a quadrilateral or a hexagon.

5. The multi-band intelligent radiation temperature control device according to claim 4, characterized in that, The orthographic projection of the first micro-unit onto the protective layer is a first equilateral triangle, and the orthographic projection of the second micro-unit onto the protective layer is a second equilateral triangle, wherein the side length of the first equilateral triangle is greater than the side length of the second equilateral triangle; Within the same modulation region, the corresponding sides of the second equilateral triangle are arranged parallel to the corresponding sides of the first equilateral triangle.

6. The multi-band intelligent radiation temperature control device according to claim 5, characterized in that, The first micro-unit is provided with a first circular hole and three third circular holes, and the second micro-unit is provided with a second circular hole. The diameter of the first circular hole is larger than the diameter of the second circular hole. Wherein, the center of the first circular hole coincides with the center of the first micro-unit, and the center of the second circular hole coincides with the center of the second micro-unit; the shortest distance from the first circular hole to any of the third circular holes is the same.

7. The multi-band intelligent radiation temperature control device according to claim 5, characterized in that, The side length of the first equilateral triangle is 8~15 μm, and the side length of the second equilateral triangle is 3~6.5 μm; the minimum angle between the side of the first equilateral triangle or the side of the second equilateral triangle and the length direction of the optical functional layer is -15°~15°.

8. The multi-band intelligent radiation temperature control device according to claim 1, characterized in that, The first micro-unit or the second micro-unit is made of pure vanadium dioxide or doped vanadium dioxide, and the doping element of the doped vanadium dioxide includes at least one of tungsten, copper, chromium, gallium, aluminum, iron, titanium, niobium, molybdenum, rhenium, fluorine, carbon and hydrogen.

9. The multi-band intelligent radiation temperature control device according to claim 1, characterized in that, The multi-band intelligent radiation temperature control device also includes a reflective layer disposed below the optical functional layer. The reflective layer is made of at least one of the following materials: metal thin film, graphene, carbon nanotubes, metal nanowires, metal mesh, conductive polymer, and low-emissivity glass. The metal thin film includes at least one of the following materials: aluminum, iron, copper, silver, gold, chromium, nickel, platinum, tin, titanium, indium tin oxide, aluminum zinc oxide, and gallium-doped zinc oxide.

10. The multi-band intelligent radiation temperature control device according to claim 1, characterized in that, The protective layer is made of at least one of polyethylene, colored polyethylene, EPDM rubber, polytetrafluoroethylene, polymethylpentene, MXene, hafnium oxide, magnesium fluoride, barium fluoride, and calcium fluoride.

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