CN114543373B - Spectrum regulation and control device based on solar thermal radiation and space cold radiation - Google Patents

Abstract

The invention relates to a spectrum regulating and controlling device based on solar thermal radiation and space cold radiation, and belongs to the technical field of energy utilization. The spectrum regulating and controlling device is of a thin plate or film structure and is formed by sequentially connecting a transparent substrate, a transparent electrode, an electrolyte, a counter electrode, a reflecting layer and a lower substrate from top to bottom. Under the action of an electric field, the spectral characteristics of the spectral regulation device are actively converted, and the solar photo-thermal conversion in winter and the radiation refrigeration in summer and daytime are combined and utilized. Specifically, the method comprises the following steps: when working under the condition of negative voltage, the absorptivity of the solar radiation wave band of 0.3-3 mu m is more than 0.85, and the reflectivity of the infrared wave band of 3-25 mu m is more than 0.85; when the solar photovoltaic power generation device works under the positive voltage condition, the reflectivity of a solar radiation wave band of 0.3-3 mu m is more than 0.85,3-25 mu m, and the emissivity of an infrared wave band is more than 0.85. When the energy-saving heat-preserving agent is used on the surface of a building, 48.7 percent of heating energy consumption of the building in winter is saved under the negative voltage in winter; under summer and positive voltage, 56.4 percent of refrigeration energy consumption of buildings in summer is saved.

Description

A spectrum control device based on solar thermal radiation and space cold radiation

technical field

The invention belongs to the technical field of energy utilization, and specifically relates to metal deposition electrochromism based on localized surface plasmon resonance (LSPR), sky radiation cooling (RSC) and solar photothermal conversion (PT).

Background technique

Cold and heat energy account for about 51% of the total social energy consumption, and are the two most widely used main forms of energy. The vast majority of cooling and heat demand is the cooling and heating load caused by the fluctuation of ambient temperature (referred to as ambient temperature). For example, the energy consumption of heating in winter and air conditioning in summer accounts for about 77% of the total energy consumption of buildings, and the energy consumption of buildings accounts for one-third of the total energy consumption of society.

Photothermal conversion is a way of converting solar radiation into thermal energy by using spectrally selective coatings to increase solar radiation absorption and reduce mid-infrared emission. Sky radiative cooling uses the low-temperature background in space as the object of radiation heat transfer, suppresses the absorption of the solar band (high reflection), and strengthens the emission of the mid-infrared band to achieve passive cooling of surface objects. Using radiant cooling technology in summer, the building can obtain cold energy without consuming additional energy, thus lowering the ambient temperature. Using solar photothermal conversion technology in winter, buildings can convert solar radiation into heat to achieve heating effects. There is spectral conflict between solar thermal collection and radiative cooling in terms of spectral selection, so it is difficult to realize the combination of spectral utilization of radiative cooling in summer and solar thermal collection in winter.

Contents of the invention

In order to realize the dynamic control of the sky radiative cooling spectrum and photothermal conversion spectrum, the invention provides an electrochromic technology based on solar thermal radiation and space cooling radiation by using the metal deposition electrochromic technology based on localized surface plasmon resonance effect (LSPR). spectral control device.

A spectrum control device based on solar heat radiation and space cooling radiation is a hard thin plate or flexible film structure, which is composed of a transparent substrate, a transparent electrode, an electrolyte, a counter electrode, a reflective layer and a lower substrate connected sequentially from top to bottom;

The transparent substrate is a polyethylene (PE) film with a transmittance greater than 0.9 in the whole band of 0.3-25 μm;

The transparent electrode is a microstructured conductive layer through which the whole band is transmitted, and the material of the microstructured conductive layer is a microstructured metal film with a transmittance of more than 0.9 in the whole band of 0.3-25 μm;

The electrolyte is a solid mixture with a transmittance greater than 0.9 in the 0.3-3 μm solar radiation band and an emissivity greater than 0.9 in the 3-25 μm mid-infrared band; the solid mixture is a gel electrolyte;

The counter electrode is an ITO conductive film layer with an absorption rate of less than 0.08 in the 0.3-3 μm solar radiation band;

The reflective layer is a silver film with a reflectivity greater than 0.95 in the 0.3-3 μm solar radiation band;

The material of the lower substrate is a thin copper plate or a polyethylene terephthalate (PET) film, which provides support;

When working under negative voltage conditions, the metal nanoparticles are reduced from the electrolyte and deposited on the transparent electrode. When the incident photon frequency matches the overall vibration frequency of the metal nanoparticles, the metal nanoparticles have a strong absorption effect on the photon energy. , the local surface plasmon effect will be generated, and a strong resonant absorption peak will be generated in the spectrum; at this time, the absorption rate of the metal nano-deposited layer is greater than 0.9 in the 0.3-3 μm solar radiation band, and the reflectance in the 3-25 μm mid-infrared band rate greater than 0.9; when working under positive voltage conditions, the metal nanoparticles on the transparent electrode are oxidized and dissolved in the electrolyte; the metal nanoparticles are silver nanoparticles or lead nanoparticles;

When working under negative voltage conditions, the spectrum control device has an absorptivity greater than 0.85 in the 0.3-3 μm solar radiation band, and a reflectivity greater than 0.85 in the 3-25 μm mid-infrared band;

When working under the condition of positive voltage, the reflectance of the spectrum regulating device is greater than 0.85 in the solar radiation band of 0.3-3 μm, and the emissivity of the mid-infrared band of 3-25 μm is greater than 0.85.

Further defined technical solutions are as follows:

The material of the transparent base 1 is a polyethylene (PE) film with a thickness less than 0.05mm.

The transparent electrode is a microstructured platinum (Pt) metal film or a microstructured gold (Au) metal film with a thickness less than 1000 nm prepared on the transparent substrate 1 .

The electrolyte 3 consists of 100ml dimethyl sulfoxide (DMSO) as solvent, 0.85g silver nitrate (AgNO ₃ ), 0.13g copper chloride (CuCl ₂ ) and 2.17g lithium bromide (LiBr) as solute, 11g polyvinyl alcohol Butyraldehyde (PVB) is an electrolyte gel, mix well to form a solid gel electrolyte or use 100ml dimethyl sulfoxide (DMSO) as a solvent, 1.65g lead nitrate (Pb(NO ₃ ) ₂ ), 0.13g copper chloride ( CuCl ₂ ) and 2.17 lithium bromide (LiBr) as the solute, and 11g of polyvinyl butyral (PVB) are mixed uniformly to form a solid gel electrolyte.

The counter electrode 4 is an ITO conductive film layer with a thickness less than 300nm.

The reflective layer 5 is a silver reflective layer with a thickness less than 0.01 mm.

The lower substrate 6 is a thin copper plate with a thickness greater than 1 mm or a polyethylene terephthalate (PET) film with a thickness greater than 0.01 mm.

The microstructured metal thin film is a microstructured platinum metal thin film, and the preparation operation of the microstructured platinum metal thin film is as follows: a layer of 100 nm thick platinum metal thin film is formed on the transparent substrate 1 through an evaporation process; , development, etching, and stripping to obtain a fine metal grid. The width, spacing, and thickness of the microgrid are 10 μm, 1 mm, and 100 nm, respectively; and then a 1 nm thick platinum metal film is evaporated.

Beneficial technical effect of the present invention is embodied in the following aspects:

1. In the present invention, under the active control of the electric field, the spectrum of the spectrum control device can be dynamically converted, realizing the combined utilization of solar light-to-heat conversion in winter and daytime radiation cooling in summer. Under negative voltage conditions (the transparent electrode is connected to the negative pole of the power supply, and the counter electrode is connected to the positive pole of the power supply), the metal ions in the electrolyte obtain electrons from the transparent electrode to form metal nanoparticles, and the metal nanoparticles are adsorbed on the transparent electrode with a microstructure. Due to the metallic nature of the metal nanoparticles, the adsorption layer has low emission in the mid-infrared band. When the overall vibration frequency of the metal nanoparticles adsorbed on the transparent electrode with a microstructure matches the frequency of the incident photons, the metal nanoparticles have a negative impact on the photon energy. A strong absorption effect will produce a localized surface plasmon effect, which will produce a strong resonant absorption peak in the spectrum, so the adsorption layer has high absorption in the solar radiation band. At this time, the device as a whole has a spectral characteristic of high absorption in the solar radiation band and low emission in the mid-infrared band, that is, the PT spectral feature. Under positive voltage conditions (the transparent electrode is connected to the positive pole of the power supply, and the opposite electrode is connected to the negative pole of the power supply), the metal nanoparticles on the transparent electrode are deposited and dissolved in the electrolyte. High emission in the mid-infrared band. At this time, the device as a whole has the spectral characteristics of high reflection in the solar band and high emission in the mid-infrared band, that is, the RSC spectral feature.

2. The spectrum control device of the present invention has a reasonable structural design and is easy to use, and can be used on the outer surface of buildings, etc., saving energy consumption for building heating and cooling. The invention is used on the surface of buildings. In winter, under negative voltage, the PT mode has high absorption in the solar radiation band and low emission in the mid-infrared band, so that the building can absorb solar radiation energy to obtain heat, and reduce radiation heat dissipation, saving winter buildings. 48.7% of the heating energy consumption, and in the absence of an air-conditioning system, the average indoor temperature is 5°C higher than that of ordinary buildings; in summer, under positive voltage, the RSC mode has the spectral characteristics of low absorption in the solar radiation band and high emission in the mid-infrared band, The building can reflect solar radiation energy and emit mid-infrared radiation energy to obtain cooling capacity, saving 56.4% of building cooling energy consumption in summer. At the same time, without an air-conditioning system, the average indoor temperature is 1.2°C lower than that of ordinary buildings. The invention can respectively save heating energy consumption in winter and cooling energy consumption in summer by adjusting spectral characteristics. It can also actively control heat gain and loss according to heating and cooling needs.

Description of drawings

Figure 1 is a schematic diagram of a spectrum control device based on solar thermal radiation and space cooling radiation.

Figure 2 is a cross-sectional view of the RSC mode of the spectrum control device based on solar thermal radiation and space cold radiation.

Fig. 3 is a PT mode cross-sectional view of a spectrum control device based on solar thermal radiation and space cooling radiation.

Fig. 4 is a schematic diagram of an energy-saving building in an embodiment.

Fig. 5 is a cross-sectional view of the energy-saving building of the embodiment.

Fig. 6 is a temperature simulation diagram of an energy-saving building in PT mode.

Fig. 7 is a temperature simulation diagram of an energy-saving building in RSC mode.

Fig. 8 is a simulation diagram of heating energy consumption of an energy-saving building in PT mode.

Figure 9 is a simulation diagram of cooling energy consumption of energy-saving buildings in RSC mode.

Serial numbers in the above figure: transparent substrate 1, transparent electrode 2, electrolyte 3, counter electrode 4, reflective layer 5, lower substrate 6, metal nanoparticle deposition 7, structural wall 8, double-glazed window 9, foam concrete wall 10, spectrum Control device 11, concrete floor 12.

Detailed ways

The present invention will be further described through the embodiments below in conjunction with the accompanying drawings.

Example 1

Referring to Figure 1, a spectrum control device based on solar thermal radiation and space cooling radiation is a hard thin plate structure with an area of 10cm×10cm; referring to Figure 2, it consists of a transparent substrate 1, a transparent electrode 2, an electrolyte 3, and a substrate from top to bottom. The electrode 4, the reflective layer 5 and the lower substrate 6 are sequentially connected to form.

The material of the transparent substrate 1 is a polyethylene (PE) film with a thickness of 5 mm, and the average transmittance in the whole band of 0.3-25 μm is 0.94.

The transparent electrode 2 is a microstructured platinum (Pt) metal film prepared on a polyethylene film with a platinum (Pt) metal layer with a thickness of 100 nm, and has an average transmittance of 0.96 in the entire wavelength range from 0.3 to 25 μm.

The preparation operation of the microstructured platinum metal film is as follows: a layer of 100nm thick platinum metal film is formed on the transparent substrate 1 by evaporation process; Metal grid, the width, spacing and thickness of the micro-grid are 10 μm, 1 mm and 100 nm, respectively; and then a layer of platinum metal film with a thickness of 1 nm is evaporated.

Electrolyte 3 consists of 25ml dimethyl sulfoxide (DMSO) as solvent, 0.85g silver nitrate (AgNO ₃ ), 0.13g copper chloride (CuCl ₂ ) and 2.17g lithium bromide (LiBr) as solute, 11g polyvinyl butyral (PVB) is an electrolyte gel, a solid gel electrolyte formed by mixing uniformly; the average transmittance in the 0.3-3μm solar radiation band is 0.95, and the average emissivity in the 3-25μm mid-infrared band is 0.96.

The counter electrode 4 is an ITO conductive film layer with a thickness of 100nm, and the average absorption rate in the solar radiation band of 0.3-3.0μm is 0.04.

The reflective layer 5 is a silver reflective layer with a thickness of 0.01 mm, and the average reflectance in the 0.3-3.0 μm solar radiation band is 0.98.

The material of the lower substrate 6 is a thin copper plate with a thickness of 1 mm.

Silver nanoparticle deposition 7 is under the condition of negative voltage, silver is reduced from the electrolyte and deposited on the transparent electrode, the average absorptivity of the silver nano-deposition layer is 0.93 in the 0.3-3μm solar radiation band, and the average reflectance in the 3-25μm mid-infrared band 0.93, when working under positive voltage conditions, the silver nanoparticles on the transparent electrode are oxidized and dissolved in the electrolyte.

The spectrum control device of this embodiment has two working modes, see Fig. 3, negative voltage condition (PT mode), the silver nanoparticle deposition 7 is adsorbed on the transparent electrode 2 of the microstructured platinum metal film, and the localized surface plasmon Under the influence of the resonance effect, the device has an average absorption rate of 0.9 in the 0.3-3 μm solar radiation band, and an average reflectance of 0.91 in the 3-25 μm mid-infrared band. See Figure 2, under positive voltage conditions (RSC mode), silver nanoparticles deposited 7 are desorbed and dissolved in the electrolyte 3, making the device have an average reflectance of 0.9 in the 0.3-3 μm solar radiation band and an average emission in the 3-25 μm mid-infrared band Rate 0.91.

Example 2

The main difference from Example 1 is that the transparent electrode 2 is different: the transparent electrode 2 is a microstructure gold metal thin film with a thickness of 100 nm, and the average transmittance in the whole band of 0.3-25 μm is 0.95.

The microstructure of the microstructured gold metal thin film is the same as that of the microstructured platinum metal thin film in Example 1. This change did not affect the deposition of silver nanoparticles and therefore did not affect the spectral properties of the silver nanoparticle deposition 7 .

The spectrum control device of this embodiment has two working modes, see Fig. 3, negative voltage condition (PT mode), the silver nanoparticle deposition 7 is adsorbed on the transparent electrode 2 of the microstructured gold metal film, and the localized surface plasmon Under the influence of the resonance effect, the device has an average absorption rate of 0.89 in the 0.3-3 μm solar radiation band, and an average reflectance of 0.9 in the 3-25 μm mid-infrared band. See Figure 2, under positive voltage conditions (RSC mode), silver nanoparticles deposited 7 are desorbed and dissolved in the electrolyte 3, making the device have an average reflectance of 0.89 in the 0.3-3 μm solar radiation band, and an average emission in the 3-25 μm mid-infrared band Rate 0.9.

Example 3

The main difference from Example 1 is that electrolyte 3 is different: 100ml dimethylsulfoxide (DMSO) is used as solvent, 1.65g lead nitrate (Pb(NO ₃ ) ₂ ), 0.13g copper chloride (CuCl ₂ ) and 2.17g lithium bromide ( LiBr) is the solute, and 11g of polyvinyl butyral (PVB) is mixed evenly to form a solid gel electrolyte. The average transmittance in the 0.3-3μm solar radiation band is 0.95, and the average emissivity in the 3-25μm mid-infrared band is 0.96.

Lead nanoparticle deposition 7 is under the condition of negative voltage, lead is reduced from the electrolyte and deposited on the transparent electrode, the average absorption rate of the lead nanoparticle deposition layer is 0.94 in the 0.3-3 μm solar radiation band, and the average reflectance in the 3-25 μm mid-infrared band When the ratio is 0.93, the lead nanoparticles on the transparent electrode are oxidized and dissolved in the electrolyte when working under positive voltage conditions.

The spectrum control device of this embodiment has two working modes, see Fig. 3, negative voltage condition (PT mode), the lead nanoparticle deposition 7 is adsorbed on the transparent electrode 2 of the microstructured platinum metal film, and the localized surface plasmon Under the influence of the resonance effect, the device has an average absorption rate of 0.91 in the 0.3-3 μm solar radiation band, and an average reflectance of 0.9 in the 3-25 μm mid-infrared band. See Figure 2, under the condition of positive voltage (RSC mode), the lead nanoparticle deposition 7 is desorbed and dissolved in the electrolyte 3, making the device have an average reflectance of 0.9 in the 0.3-3 μm solar radiation band and an average emission in the 3-25 μm mid-infrared band Rate 0.91.

Example 4

The main difference from Example 1 is that the lower base 6 is different: the material of the lower base 6 is replaced with a PET film with a thickness of 0.1 mm. With this change, a spectrum control device with a flexible thin film structure can be obtained.

The working mode and spectral performance of the spectrum control device of this embodiment are the same as those of the spectrum control device of Example 1.

Example 5

Referring to Fig. 4 and Fig. 5, an energy-saving building with the spectrum control device of the present invention installed on the surface.

The energy-saving building wall 8 is a foam concrete wall 2 with a spectrum control device 11 installed on the surface, and the glass window 9 is double-glazed. Set the control group, common building model. Different from energy-saving buildings, the invention is not installed on the foam concrete surface of common buildings. Foamed concrete is used for the walls and roof, concrete for the floor, ordinary silicate glass for the windows, and quality is not considered for the spectral control devices. The spectral parameters of different modes of the spectrum control device of the present invention are set as follows: under negative voltage conditions (PT mode), the average absorptivity emissivity in the 0.3-3 μm solar radiation band is 0.91, the average reflectance is 0.09, and the average emissivity in the 3-25 μm mid-infrared band is 0.1 , The average reflectance is 0.9; under positive voltage conditions (RSC mode), the average absorptivity of 0.3-3μm solar radiation band is 0.1, and the average reflectance is 0.9, and the average emissivity of 3-25μm mid-infrared band is 0.91, and the average reflectance is 0.09.

The energy-saving building is 8m long, 6m wide, and 2.7m high. The thickness of the foam concrete wall is 0.12m, the thermal conductivity is 0.6W/(m·K), the density is 1600kg/m ³ , the specific heat is 900J/(kg·K), the average absorption rate of 0.3～3.0μm solar radiation band is 0.6, and the average absorption rate of 3～25μm The average emissivity of the infrared band is 0.85. Concrete floor thickness 0.12m, thermal conductivity 1.6W/(m·K), density 2240kg/m ³ , specific heat 900J/(kg·K), average absorption rate of 0.3～3.0μm solar radiation band 0.6, 3～25μm mid-infrared The average emissivity of the band is 0.85. Glass window 9 is double-glazed on the east wall of the building. The single-layer glass is 3m long, 2m high, and 6mm thick. The double-layer glass sandwiches 3mm air between two glasses of the same specification. The glass is ordinary silicate glass with a thermal conductivity of 0.9W/(m K), an average transmittance of 0.775 and an average reflectance of 0.142 in the 0.3-3.0μm solar radiation band, and an average emissivity of 0.84 and an average transmittance of 3-25μm mid-infrared band. Overrate 0.

Perform temperature and energy simulations on building models. The temperature simulation is carried out without an air-conditioning system, simulating the indoor air temperature on January 1 and July 1 in Hefei. Energy consumption simulation Under the action of the air conditioning system, set the indoor temperature at 25°C-24°C to simulate the heating and cooling energy consumption of buildings in Hefei throughout the year.

The temperature simulation of the energy-saving building model is carried out on January 1 and July 1 in Hefei respectively. On January 1st in Hefei, see Figure 6, under the PT working mode, the room temperature of energy-saving buildings was 14°C higher than the ambient temperature on average and 5°C higher than that of ordinary buildings. In Hefei area on July 1, see Figure 7, under the RSC working mode, the room temperature of energy-saving buildings was 2°C lower than the ambient temperature on average and 1.2°C lower than that of ordinary buildings.

The annual energy consumption simulation of energy-saving buildings in Hefei area is carried out. As shown in Figure 8, under PT working mode, energy-saving buildings save 48.7% of heating energy consumption compared with ordinary buildings; as shown in Figure 9, under RSC working mode, energy-saving buildings save 78.9% of cooling energy consumption compared with ordinary buildings. The total heating and cooling energy consumption of energy-saving buildings throughout the year is 56.4% lower than that of ordinary buildings.

Those skilled in the art can easily understand that the above embodiments 1-5 are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and modifications made within the spirit and principles of the present invention Improvements and the like should all be included within the protection scope of the present invention.

Claims (7)

1. A spectrum control device based on solar thermal radiation and space cooling radiation, characterized in that: the spectrum control device is a hard thin plate or flexible film structure, from top to bottom by transparent substrate, transparent electrode, electrolyte, counter electrode , the reflective layer and the lower substrate are sequentially connected to form; The transparent substrate is a film with a transmittance greater than 0.9 in the whole band of 0.3-25 μm; The transparent electrode is a microstructured conductive layer that transmits through the whole band, and the material of the microstructured conductive layer is a microstructured metal film with a transmittance of more than 0.9 in the whole band of 0.3-25 μm; The electrolyte is a solid mixture with a transmittance greater than 0.9 in the 0.3-3 μm solar radiation band and an emissivity greater than 0.9 in the 3-25 μm mid-infrared band; the solid mixture is a gel electrolyte; The counter electrode is an ITO conductive film layer with an absorption rate of less than 0.08 in the 0.3-3 μm solar radiation band; The reflective layer is a silver coating with a reflectivity greater than 0.95 in the 0.3-3 μm solar radiation band; The lower base material is thin copper plate or PET film, which provides support; When working under negative voltage conditions, the metal nanoparticles are reduced from the electrolyte and deposited on the transparent electrode. When the incident photon frequency matches the overall vibration frequency of the metal nanoparticles, the metal nanoparticles have a strong absorption effect on the photon energy. , the local surface plasmon effect will be generated, and a strong resonant absorption peak will be generated in the spectrum; at this time, the absorption rate of the metal nano-deposited layer is greater than 0.9 in the 0.3-3 μm solar radiation band, and the reflectance in the 3-25 μm mid-infrared band rate greater than 0.9; when working under positive voltage conditions, the metal nanoparticles on the transparent electrode are oxidized and dissolved in the electrolyte; the metal nanoparticles are silver nanoparticles or lead nanoparticles; When working under negative voltage conditions, the spectrum control device has an absorptivity greater than 0.85 in the 0.3-3 μm solar radiation band, and a reflectivity greater than 0.85 in the 3-25 μm mid-infrared band; When working under the condition of positive voltage, the reflectance of the spectrum regulating device is greater than 0.85 in the solar radiation band of 0.3-3 μm, and the emissivity of the mid-infrared band of 3-25 μm is greater than 0.85. 2. The spectrum control device based on solar thermal radiation and space cooling radiation according to claim 1, characterized in that: the material of the transparent substrate (1) is a polyethylene film with a thickness less than 0.05 mm. 3. The spectrum control device based on solar thermal radiation and space cold radiation according to claim 1, characterized in that: the transparent electrode is a microstructured platinum metal film or a microstructured gold film with a thickness less than 1000 nm prepared on a transparent substrate metal film. 4. The spectrum control device based on solar thermal radiation and space cold radiation according to claim 1, characterized in that: the electrolyte is composed of dimethyl sulfoxide, silver nitrate, cupric chloride, lithium bromide, polyvinyl butyral A solid gel electrolyte formed by uniform mixing of aldehydes or a solid gel electrolyte formed by uniform mixing of dimethyl sulfoxide, lead nitrate, copper chloride, lithium bromide, and polyvinyl butyral. 5. The spectrum control device based on solar thermal radiation and space cooling radiation according to claim 1, characterized in that: the counter electrode is an ITO conductive film layer with a thickness less than 300 nm. 6. The spectrum control device based on solar heat radiation and space cold radiation according to claim 1, characterized in that: the reflective layer is a silver reflective layer with a thickness less than 0.01 mm. 7. The spectrum control device based on solar thermal radiation and space cold radiation according to claim 1, characterized in that: the lower base material is a thin copper plate with a thickness greater than 1 mm or polyethylene terephthalate with a thickness greater than 0.01 mm Diester film.

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