A photovoltaic chromatic facade

Abstract

This application belongs to the field of building facade technology, and particularly relates to a photovoltaic color-changing facade. The photovoltaic color-changing facade includes: a photovoltaic layer and a thermochromic layer disposed on the exterior of the building. The photovoltaic layer faces outwards, and the thermochromic layer faces inwards. The thermochromic layer includes a plurality of adjacent and closely arranged photochromic glasses, and the photovoltaic layer includes a plurality of adjacent and closely arranged photovoltaic glasses. The photochromic glass includes a transparent encapsulation shell and a thermochromic material, with the thermochromic material located inside the transparent encapsulation shell. The thermochromic material is a colloid composed of hydroxypropyl cellulose and sodium chloride as solutes, and distilled water as a solvent. When the temperature of the thermochromic material exceeds a first color-changing temperature, the thermochromic material gradually turns into a white, opaque state. This application, while utilizing solar radiation for photovoltaic power generation, automatically regulates the lighting and heat gain inside the building, improving the comfort of indoor occupants.

Description

Technical Field

[0001] This application belongs to the field of building facade technology, and in particular relates to a photovoltaic color-changing facade. Background Technology

[0002] The existence of building facades is not only used to showcase the aesthetic appeal of buildings, but also increasingly focuses on the realization of functionality.

[0003] Glass curtain wall facades are a common type of building facade today. They are not only aesthetically pleasing and easy to clean, but their high transparency also allows for ample natural light to the interior of the building.

[0004] In the cold winter, ample natural light not only provides illumination but also increases indoor heat gain, keeping the room warm and reducing the need for heating. However, in the hot summer, intense direct sunlight can interfere with normal work (e.g., making it difficult to see bright screens) and cause excessively high indoor temperatures, placing a heavy burden on cooling systems. Furthermore, glass curtain walls receive a vast area of ​​solar radiation, but this extensive solar radiation is not fully utilized. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide a photovoltaic color-changing facade that can fully utilize solar radiation for photovoltaic power generation while automatically regulating the lighting and heat gain of the building interior, thereby improving the comfort of indoor occupants.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] A photovoltaic color-changing facade includes: a photovoltaic layer and a thermochromic layer disposed on the exterior of the building, the photovoltaic layer facing outwards and the thermochromic layer facing inwards. The thermochromic layer includes a plurality of adjacent and closely arranged color-changing glasses, and the photovoltaic layer includes a plurality of adjacent and closely arranged photovoltaic glasses. The color-changing glass includes a transparent encapsulation shell and a thermochromic material, the thermochromic material being located inside the transparent encapsulation shell. The thermochromic material is a colloidal substance composed of hydroxypropyl cellulose and sodium chloride as solutes and distilled water as a solvent. When the temperature of the thermochromic material is below a first color-changing temperature T1, the thermochromic material is colorless and transparent. When the temperature of the thermochromic material reaches the first color-changing temperature T1, the thermochromic material gradually becomes white and opaque. When the temperature of the thermochromic material is above a second color-changing temperature T2, the opacity of the thermochromic material is its own peak opacity; 0 < T1 < T2.

[0008] Preferably, a bimetallic strip is provided at both the top and bottom of the photovoltaic glass; the space between the photovoltaic glass and the photochromic glass is a gas exchange channel; when the temperature of the bimetallic strip is lower than the first deformation temperature, the bimetallic strip covers the top and bottom of the photovoltaic glass, isolating the gas exchange channel from the outside; when the temperature of the bimetallic strip is higher than the first deformation temperature, the bimetallic strip curls up towards the outside, and the gas exchange channel connects with the outside.

[0009] Preferably, ventilation baffles are provided at both the top and bottom of the photochromic glass; opening or closing the ventilation baffles allows the air exchange duct to be connected to or isolated from the interior.

[0010] Preferably, the production of photochromic glass includes the following steps:

[0011] S1, Assemble and fix transparent tempered glass into a rectangular cavity with an injection port;

[0012] S2, After filling the rectangular cavity with the prepared thermochromic material through the injection port, the injection port is sealed; the rectangular cavity with the injection port sealed is the transparent encapsulation shell;

[0013] S3. After the transparent encapsulation shell filled with thermochromic material is left to stand for several hours, the thermochromic glass is obtained.

[0014] Preferably, S1 also includes S11 to S13:

[0015] S11, Place a piece of tempered high-transparency glass horizontally, use double-sided nano tape as an adhesive, and stick it along the outer edge of the upper surface of the tempered high-transparency glass until a break of length L is left.

[0016] S12, place another identical piece of tempered high-transparency glass horizontally onto the surface of the tempered high-transparency glass that has been covered with double-sided nano-adhesive tape, and then press it down; the joints on the sides of the two pieces of tempered high-transparency glass where the adhesive is missing are the injection ports.

[0017] S13, wait for the adhesive to completely solidify to obtain a rectangular cavity;

[0018] In S2: Place the rectangular cavity vertically with the side containing the injection port facing upwards. Use a needle syringe to fill the rectangular cavity with the prepared thermochromic material, and immediately seal the injection port with sealant. Then place the transparent encapsulation shell filled with thermochromic material horizontally.

[0019] The preparation of thermochromic materials also includes S1´~S3´:

[0020] S1´, hydroxypropyl cellulose, sodium chloride and distilled water are mixed in a set mass ratio to obtain a mixture;

[0021] S2´, the mixture is stirred evenly for 48 hours at a speed of 200 rpm;

[0022] S3´, let the stirred mixture stand until there are no more air bubbles in the mixture. At this point, the mixture is the thermochromic material.

[0023] Preferably, the photovoltaic glass is a transparent copper indium gallium selenide (CIGS) photovoltaic glass, which generates photovoltaic power when exposed to outdoor sunlight.

[0024] Preferably, the photovoltaic glass is a double-sided photovoltaic glass, which is composed of two pieces of glass and a double-sided photovoltaic power generation panel, with the double-sided photovoltaic power generation panel located between the two pieces of glass; one side of the double-sided photovoltaic glass generates photovoltaic power due to the illumination of outdoor light, and the other side of the double-sided photovoltaic glass generates secondary photovoltaic power due to the reflection of light from the photochromic glass.

[0025] Preferably, the thermochromic material is a colloid composed of 6 wt% hydroxypropyl cellulose, sodium chloride, and distilled water. Based on a sodium chloride concentration within the range of 0% to 2%, the photochromic glass is designed as follows: the sodium chloride concentration in the thermochromic material is calculated according to the first color-changing temperature T1 requirement; then, based on the sodium chloride concentration, the upper limit of the photochromic glass height is calculated when the total potential energy of the thermochromic material is above the stable potential energy threshold. Ensure the height of the photochromic glass does not exceed the upper limit. Alternatively, based on the preset height of the thermochromic glass on the exterior facade of the floor, calculate the concentration of sodium chloride that should be added to the thermochromic material inside the thermochromic glass when the total potential energy of the thermochromic material is above the stable potential energy threshold.

[0026] Preferably, the sodium chloride concentration in the thermochromic material is calculated based on the first color-changing temperature T1, including:

[0027] ;

[0028] in, This indicates the numerical value of sodium chloride concentration;

[0029] Calculate the total potential energy of the thermochromic material, including the following:

[0030] ;

[0031] ;

[0032] ; ;

[0033] ;

[0034] ;

[0035] Where H represents the height of the photochromic glass; T represents the temperature of the thermochromic material. This indicates the height H of the photochromic glass, the temperature T of the thermochromic material, and the sodium chloride concentration. The total potential energy of the thermochromic material under the given conditions; This represents the electrostatic repulsion potential energy; Indicates van der Waals strength; Represents pressure potential energy; This indicates the numerical value of sodium chloride concentration; Pi is a constant. This represents the dielectric constant of the thermochromic material colloid. Represents the vacuum permittivity; Indicates the particle radius of thermochromic materials; Indicates surface potential; Indicates the effective distance between colloidal particles; Indicates the shielding length; e represents the electron charge; I represents the ionic strength; Denotes Boltzmann constant; A denotes van der Waals constant; Indicates the initial particle spacing; Indicates particle spacing correction; Indicates the adjustment factor; Indicates the density of thermochromic materials; Represents gravitational acceleration; This represents Young's modulus.

[0036] Preferably, when T is the lower limit of the local ambient temperature T3, let The upper limit of the height of the photochromic glass was then calculated. ;in, This represents the stable potential energy threshold; or, when T=T3, let The concentration of sodium chloride that should be added to the thermochromic material inside the photochromic glass was then determined. Among them, if the sodium chloride concentration If it is within the range of 0% to 2%, then it should be based on the current sodium chloride concentration. After manufacturing the thermochromic material, photochromic glass is then manufactured according to a predetermined height; if the sodium chloride concentration... If the concentration is outside the 0% to 2% range, the current preset height for the photochromic glass on the exterior facade of that floor will not be adopted; after reducing the preset height for the photochromic glass on the exterior facade of that floor, the sodium chloride concentration will be recalculated. until the sodium chloride concentration It is within the range of 0% to 2%.

[0037] The beneficial effects of this application are as follows:

[0038] (1) A photovoltaic color-changing facade of this application can make full use of the large area of ​​solar radiation received by the facade to generate photovoltaic power, while adapting to the temperature changes of the four seasons and automatically regulating the lighting and heat gain of the building interior to improve the comfort of indoor personnel.

[0039] (2) In the hot summer, the thermochromic layer of the photovoltaic color-changing facade can automatically become incompletely transparent or opaque, reducing the indoor light transmittance and avoiding direct sunlight on the interior. At the same time, it greatly reduces the heat gain caused by direct sunlight on the interior, further reducing the indoor temperature and improving indoor comfort.

[0040] (3) In a photovoltaic color-changing facade of this application, when a portion of outdoor sunlight penetrates the photovoltaic glass and reaches the color-changing glass, the color-changing glass reflects this portion of sunlight, allowing the back of the photovoltaic glass to generate secondary photovoltaic power due to the reflected light from the color-changing glass, thereby improving the photovoltaic power generation efficiency. When the ambient temperature is high, the opacity of the color-changing glass reaches its peak, and the visible light reflectance of the color-changing glass also reaches its peak, further enhancing the secondary photovoltaic power generation efficiency on the back of the photovoltaic glass. When the thermochromic layer is exactly the same, when the photovoltaic glass is double-sided photovoltaic glass, the light transmittance coefficient of the photovoltaic color-changing facade is lower than that of transparent copper indium gallium selenide photovoltaic glass, but the photovoltaic power generation efficiency is higher.

[0041] (4) In a photovoltaic color-changing facade of this application, the deformation state of the thermal bimetallic sheet, the opening and closing state of the ventilation baffle, and the air exchange duct can be used to automatically adjust the temperature and light transmittance of the photovoltaic color-changing facade, thereby indirectly and automatically adjusting the indoor temperature and daylighting of the building:

[0042] ① Photovoltaic glass generates electricity during clear days in spring / autumn;

[0043] ② During the hot summer days, the photovoltaic glass generates photovoltaic power, and the photochromic glass 1 reaches its respective opacity peak, exhibiting high reflectivity to visible light;

[0044] ③ On a clear day during the cold winter, the photovoltaic glass generates photovoltaic power. The color-changing glass 1 is transparent and has high light transmittance to visible light.

[0045] (5) In the prior art, indoor lighting can be reduced by drawing curtains. However, the degree of light blocking by curtains is the same in the areas where light is blocked, and the intensity of direct sunlight in the unblocked areas is also the same. Therefore, many homeowners are still disturbed by the high intensity of direct sunlight from the bottom of the window even when they draw some curtains. Or, after using curtains to block all direct sunlight, the indoor light is too dark, so indoor lighting is still needed. In contrast, the photovoltaic color-changing facade of this application, when the photovoltaic glass is transparent copper indium gallium selenide photovoltaic glass, and when the color-changing temperature and opacity peak of each piece of color-changing glass are different, can achieve shading in different areas and to different degrees for the same household, and reduce the use of lighting equipment during the day to a certain extent.

[0046] (6) This application provides a photovoltaic color-changing facade and a method for manufacturing color-changing glass. The steps are simple and the color-changing glass can be manufactured conveniently and at low cost. It also improves the stability and color uniformity of the thermochromic material inside the color-changing glass when it is placed vertically afterward by reducing the thickness of the inner cavity of the transparent encapsulation shell. It also reduces the amount of thermochromic material filled into the color-changing glass, thus saving costs.

[0047] (7) This application provides a photovoltaic color-changing facade, which is a color-changing glass that can reversibly and uniformly change color and change transparency automatically according to temperature changes, reducing the amount of sunlight directly entering the room in summer and stably regulating the indoor light in summer; avoiding the occurrence of layered color change and irreversible color change in the color-changing glass, and ensuring that the automatic regulation of indoor lighting and heat gain by the photovoltaic color-changing facade is more stable.

[0048] (8) In the design of the photovoltaic color-changing facade of this application, the upper limit of the height of the color-changing glass can be quickly determined based on the homeowner's first color-changing temperature requirement within the sodium chloride concentration range of 0% to 2%. This allows the color-changing glass to adapt to local temperature changes and change color uniformly, stably, and reversibly. The homeowner can also determine several different first color-changing temperature requirements and then obtain the upper limit of the height of the color-changing glass corresponding to these first color-changing temperature requirements. This ensures that each piece of color-changing glass can change color uniformly, stably, and reversibly, and also realizes the homeowner's personalized needs for shading by area and degree.

[0049] (9) In the design of the photovoltaic color-changing facade of this application, the existence of color-changing glass that can stably, uniformly, and reversibly change color can be quickly determined based on the homeowner's preset height of the color-changing glass. If not, the homeowner needs to reduce the preset height of the color-changing glass on the facade of their floor until it is determined that there is color-changing glass that can stably, uniformly, and reversibly change color within the 0% to 2% sodium chloride concentration range. Subsequently, thermochromic materials and color-changing glass with corresponding sodium chloride concentrations are produced and installed. This not only ensures that the color-changing glass on the facade of the homeowner's floor can stably change color, but also ensures that the height of the color-changing glass on the facade of the homeowner's floor is as large as possible, so that the homeowner has a better viewing experience. Moreover, it eliminates the need to spend a lot of time conducting color-changing stability tests on the color-changing glass at different temperatures, saving a lot of manpower and resources and improving the production efficiency of color-changing glass. Attached Figure Description

[0050] Figure 1 This is a flowchart illustrating a method for manufacturing photochromic glass according to this application;

[0051] Figure 2 A schematic diagram of the photovoltaic color-changing glass facade corresponding to each floor of the building;

[0052] Figure 3 A schematic diagram showing the photovoltaic color-changing glass facade for each floor of a building at different temperatures;

[0053] Figure 4 This is a flowchart illustrating a design method for photovoltaic color-changing facade glass according to this application;

[0054] Figure 5 This is a schematic diagram of the photovoltaic layer in a photovoltaic color-changing facade;

[0055] Figure 6 A schematic diagram of the thermochromic layer in a photovoltaic color-changing facade;

[0056] Figure 7 This is the first sectional view of the photovoltaic color-changing facade.

[0057] Figure 8 This is the second sectional view of the photovoltaic color-changing facade. Detailed Implementation

[0058] To make the technical solution of this application clearer and more explicit, the application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Solutions derived by those skilled in the art through equivalent substitution and conventional reasoning of the technical features of the technical solution of this application without creative effort all fall within the protection scope of this application.

[0059] Example 1

[0060] A photochromic glass, comprising a transparent encapsulation shell and a thermochromic material filling the interior. The thermochromic material is a colloidal substance composed of hydroxypropyl cellulose and sodium chloride as solutes, and distilled water as a solvent. The transparent encapsulation shell is tempered high-transparency glass, and the thermochromic material fills the interior of the transparent encapsulation shell.

[0061] The thermochromic material of this application uses hydroxypropyl cellulose and sodium chloride as solutes, both of which are safe, non-toxic, inexpensive, and low-cost.

[0062] Optionally, in the thermochromic material, the mass ratio of hydroxypropyl cellulose, sodium chloride, and distilled water is 3:1:46.

[0063] The manufacturing method of photochromic glass 1, as follows: Figure 1 As shown, it includes the following:

[0064] S1, assemble and fix tempered high-transparency glass into a rectangular cavity with an injection port;

[0065] S2, After filling the rectangular cavity with the prepared thermochromic material through the injection port, the injection port is sealed; the rectangular cavity with the injection port sealed is the transparent encapsulation shell;

[0066] S3. After the transparent encapsulation shell filled with thermochromic material is left to stand for several hours, the thermochromic glass is obtained.

[0067] S1 also includes the following:

[0068] S11, Place a piece of tempered high-transparency glass horizontally, use double-sided nano tape as an adhesive, and stick it along the outer edge of the upper surface of the tempered high-transparency glass until a break of length L is left.

[0069] S12, place another identical piece of tempered high-transparency glass horizontally onto the surface of the tempered high-transparency glass that has been covered with double-sided nano-adhesive tape, and then press it down; the joints on the sides of the two pieces of tempered high-transparency glass where the adhesive is missing are the injection ports.

[0070] S13, wait for the adhesive to fully solidify to obtain a rectangular cavity.

[0071] The structure on the side of the rectangular cavity, excluding the injection port, consists of "tempered high-transparency glass - adhesive - tempered high-transparency glass".

[0072] In this embodiment, the thickness of the double-sided nano-adhesive used as an adhesive is 1 mm, that is, the gap between the two pieces of high-transparency tempered glass is 1 mm; this greatly reduces the total amount of thermochromic material filled in each piece of photochromic glass, reduces the production cost of photochromic glass, and at the same time ensures that the thermochromic material is distributed more evenly and stably in the rectangular cavity.

[0073] The preparation of thermochromic materials also includes the following:

[0074] S1´, hydroxypropyl cellulose, sodium chloride and distilled water are mixed in a set mass ratio to obtain a mixture;

[0075] S2´, the mixture is stirred evenly at a speed of 200 rpm for 48 hours to ensure that hydroxypropyl cellulose and sodium chloride are fully dissolved and homogeneous in distilled water;

[0076] S3´, let the stirred mixture stand until there are no more air bubbles in the mixture. At this point, the mixture is the thermochromic material.

[0077] Thermochromic materials begin to show a significant change in color and transparency when their temperature reaches the first color-changing temperature T1.

[0078] When the temperature of the thermochromic material is below the first color-changing temperature T1, it is colorless and transparent with high light transmittance. When the temperature reaches the first color-changing temperature T1, the color and transparency of the thermochromic material begin to change, gradually becoming opaque white with decreased light transmittance. The changes in color and transparency become more pronounced with increasing temperature. When the thermochromic material reaches the second color-changing temperature T2, its opacity reaches its peak, exhibiting high reflectivity and low light transmittance. When the temperature exceeds the second color-changing temperature T2, its opacity reaches its peak and remains unchanged. 0 < T1 < T2.

[0079] During the cooling process of thermochromic materials, the changes in color and transparency are the opposite of those described above, and will not be repeated here.

[0080] This application experimentally determined that the first color-changing temperature T1 of the thermochromic material prepared by the above-described process with a mass ratio of hydroxypropyl cellulose, sodium chloride, and distilled water of 3:1:46 is 35.8℃, and the second color-changing temperature T2 is 37℃. When the opacity of the thermochromic material reaches its peak, the visible light reflectance of the photochromic glass can exceed 90%.

[0081] Optionally, thermochromic materials may also include gellan gum. Gellan gum can further enhance the stability of thermochromic materials.

[0082] In this embodiment, the weight percentage of gellan gum in the thermochromic material is 5 wt%.

[0083] The first color-changing temperature T1 of the thermochromic material can be adjusted by changing the concentration of hydroxypropyl cellulose or adding different doses of sodium chloride. When the thermochromic material reaches the first color-changing temperature T1, the visible light transmittance of the photochromic glass reaches 50% of the peak transparency of the photochromic glass. The mechanism of color and transparency changes in the thermochromic material is as follows: when the hydroxypropyl cellulose aqueous solution is exposed above its color-changing temperature, the hydrogen bonds between the polymer chains and water molecules in the hydrogel break, leading to polymer particle aggregation and greatly reducing the transparency of the hydrogel; when the temperature decreases, the polymer particles in the hydrogel re-form hydrogen bonds with water molecules, restoring the high-transmittance state.

[0084] S2 also includes the following:

[0085] Place the rectangular cavity vertically with the side containing the injection port facing upwards. Use a needle syringe to fill the rectangular cavity with the prepared thermochromic material, and immediately seal the injection port with sealant. Then place the transparent encapsulation shell filled with the thermochromic material horizontally.

[0086] The structure on the side of the rectangular cavity at the sealed injection port is "tempered high-transparency glass - adhesive - tempered high-transparency glass".

[0087] In S3, the settling time is 24 hours.

[0088] Optionally, thermochromic materials with different mass ratios can be prepared and then filled into different rectangular cavities to finally obtain thermochromic glasses with different first color-changing temperatures T1 and second color-changing temperatures T2, and / or different peak opacity values.

[0089] The photochromic glass 1 described in this application can be used not only as a building facade but also as a window, automatically adjusting indoor lighting in summer through its thermochromic properties.

[0090] The method for manufacturing photochromic glass according to this application is simple and can easily and cost-effectively produce photochromic glass 1 with the aforementioned effects. Furthermore, when constructing the transparent encapsulation shell containing the thermochromic material, traditional lamination techniques are not used for bonding; instead, nano-adhesive tape and sealant are employed. This ensures that the thickness of the inner cavity of the transparent encapsulation shell is the same as the thickness of the double-sided nano-adhesive, avoiding the excessive thickness of the inner cavity that occurs with traditional lamination techniques. This not only reduces the amount of thermochromic material filled into the photochromic glass, saving costs, but also improves the stability and uniformity of the thermochromic material filling when the photochromic glass is placed vertically.

[0091] Example 2

[0092] This application also provides a photovoltaic color-changing facade, which includes a photovoltaic layer and a thermochromic layer disposed on the exterior of the building. The photovoltaic layer faces outwards, and the thermochromic layer faces inwards. The thermochromic layer includes a plurality of adjacent and closely arranged color-changing glass 1s. The thermochromic layer, as shown in the image... Figure 6 As shown; the photovoltaic layer comprises several adjacent and closely arranged photovoltaic glass 2, as shown in the figure. Figure 5 As shown.

[0093] Cutting perpendicular to the thermochromic layer and the photovoltaic layer, as shown below... Figure 7 or Figure 8 The diagram shows a cross-sectional view of the photovoltaic color-changing facade. Photovoltaic glass 2 and color-changing glass 1 are installed between the beams and columns (the installation method of the facade is existing technology). The green part in the diagram represents the beams. Because it is a cross-sectional view and for ease of observation, the columns are not drawn.

[0094] Optionally, photovoltaic glass 2 is transparent copper indium gallium selenide photovoltaic glass (CIGS). Figure 7 (Not shown in the drawing).

[0095] Optionally, photovoltaic glass 2 is double-sided photovoltaic glass, which is composed of two pieces of glass and a double-sided photovoltaic panel, with the double-sided photovoltaic panel located between the front glass and the back glass. Figure 7 The blue portion inside the photovoltaic glass 2 represents the bifacial photovoltaic panel. Outdoor sunlight enters from the part of the bifacial photovoltaic glass that is not where the bifacial photovoltaic panel is located and reaches the photochromic glass 1. It should be noted here that... Figure 5 The double-sided photovoltaic panel is not drawn separately inside the photovoltaic glass 2.

[0096] Optionally, a thermal bimetallic strip 3 is provided at both the top and bottom of the photovoltaic glass 2; the space between the photovoltaic glass 2 and the photochromic glass 1 is referred to as the air exchange channel 5.

[0097] The thermal bimetallic strip 3 comprises an active layer metal sheet and a passive layer metal sheet composited together. The coefficient of thermal expansion of the active layer metal sheet is greater than that of the passive layer metal sheet. The active layer metal sheet faces the air exchange channel 5, and the passive layer metal sheet faces the outside. When the temperature of the thermal bimetallic strip 3 is lower than the first deformation temperature, neither the active layer metal sheet nor the passive layer metal sheet deforms, remaining flat and tightly covering the top and bottom of the photovoltaic glass 2, thus isolating the air exchange channel 5 from the outside. Figure 8As shown. When the temperature of the thermal bimetallic strip 3 is above the first deformation temperature, the active layer metal sheet and the passive layer metal sheet begin to deform. Because the coefficient of thermal expansion of the active layer metal sheet is greater than that of the passive layer metal sheet, the deformation degree of the active layer metal sheet is greater than that of the passive layer metal sheet. Since the active layer metal sheet is composite with the passive layer metal sheet, this causes the thermal bimetallic strip 3 to gradually bend towards the side where the passive layer metal sheet is located as its temperature rises. The thermal bimetallic strip 3 curls up towards the outside and no longer covers the top and bottom of the photovoltaic glass 2. At this time, the air exchange channel 5 is connected to the outside. When its temperature drops below the first temperature threshold, the thermal bimetallic strip 3 returns to a flat sheet shape and is closed again, tightly covering the top and bottom of the photovoltaic glass 2, and once again isolating the air exchange channel 5 from the outside.

[0098] Optionally, ventilation baffles 4 are provided at the top and bottom of the photochromic glass 1.

[0099] The opening or closing of the ventilation baffle 4 connects or isolates the air exchange duct 5 from the indoor environment. The homeowner can control the opening and closing status of the ventilation baffle 4 at the tinted glass 1.

[0100] Figure 7 This is the first sectional view of the photovoltaic color-changing facade. Figure 8 This is a second sectional view of the photovoltaic color-changing facade. Figure 7 and Figure 8 The perspectives are the same, the difference lies in whether the bimetallic strip 3 deforms and whether the ventilation baffle 4 is open. Figure 7 In this configuration, the bimetallic strip 3 remained undeformed, covering the top and bottom of the photovoltaic glass 2. The ventilation baffle 4 was not open, and the air exchange duct 5 was not connected to either the indoor or outdoor environment. Figure 8 In the process, the hot bimetallic strip 3 deforms and curls up towards the outside, failing to cover the top and bottom of the photovoltaic glass 2. The ventilation baffle 4 is also not open, and the air exchange duct 5 is connected to both the indoor and outdoor environments.

[0101] Optionally, the photochromic glass 1 can be filled with a thermochromic material of a corresponding mass ratio according to the homeowner's requirement for the first color-changing temperature T1, so as to meet the different homeowners' needs for indoor lighting and make the automatic adjustment of lighting in different interiors of the building more personalized.

[0102] Optional, such as Figure 2 As shown, several pieces of photochromic glass 1 are vertically installed at the thermochromic layer corresponding to each floor of the building, and each piece of photochromic glass 1 corresponding to each floor is filled with thermochromic material of different mass ratios. Figure 2 In the middle, for ease of observation, the ventilation baffles 4 set at the top and bottom of the photochromic glass 1 are not drawn.

[0103] When photovoltaic glass 2 is transparent copper indium gallium selenide (CIGS) photovoltaic glass, it has a high light transmittance. Sunlight penetrates photovoltaic glass 2 to reach photochromic glass 1, during which photovoltaic glass 2 generates photovoltaic power. Photovoltaic glass 2 automatically changes its light transmittance according to temperature changes. In hot summers, photovoltaic glass 2 can automatically become partially transparent or opaque, reducing indoor lighting and preventing direct sunlight from entering the room. This significantly reduces the heat gained indoors due to direct sunlight, further lowering the indoor temperature and improving indoor comfort. When photovoltaic glass 2 is transparent CIGS photovoltaic glass, the light transmittance of the photovoltaic photochromic facade will be even higher.

[0104] When photovoltaic glass 2 is a double-sided photovoltaic glass, the side facing outdoors is designated as the front, and the side facing photochromic glass 1 is designated as the back. When sunlight shines directly on the front of photovoltaic glass 2, it generates photovoltaic power. The double-sided photovoltaic panel blocks some of the sunlight directly entering the room, resulting in lower light transmittance of photovoltaic glass 2. Some sunlight penetrates photovoltaic glass 2 and reaches photochromic glass 1, which then reflects this sunlight, causing secondary photovoltaic power generation on the back of photovoltaic glass 2 due to the reflected light from photochromic glass 1, thus improving photovoltaic power generation efficiency. When the ambient temperature is high, the opacity of photochromic glass 1 reaches its peak, and its visible light reflectance also reaches its peak, further enhancing the secondary photovoltaic power generation efficiency on the back of photovoltaic glass 2. With identical thermochromic layers, when photovoltaic glass 2 is a double-sided photovoltaic glass, the light transmittance of the photovoltaic color-changing facade is lower than that of transparent copper indium gallium selenide photovoltaic glass, but its photovoltaic power generation efficiency is higher.

[0105] The photochromic glass 1 in the thermochromic layer automatically changes its light transmittance according to temperature changes. As the temperature rises, the photochromic glass 1 can automatically become partially transparent or opaque, reducing indoor light transmittance and preventing direct sunlight from entering the room. At the same time, it significantly reduces the heat gained indoors due to direct sunlight, further lowering the indoor temperature and improving indoor comfort.

[0106] The deformation state of the bimetallic strip 3, the on / off state of the ventilation baffle 4, and the air exchange duct 5, together with the automatic adjustment of the temperature and light transmittance of the photovoltaic color-changing facade, can indirectly and automatically regulate the building's indoor temperature and daylighting. The specific manifestations are as follows:

[0107] (1) Photovoltaic glass 2 generates photovoltaic power during clear days in spring / autumn:

[0108] If the bimetallic sheet 3 is tightly covered on the top and bottom of the photovoltaic glass 2, isolating the air exchange duct 5 from the outside, the air temperature inside the air exchange duct 5 will rise along with the photovoltaic power generation of the photovoltaic glass 2. At this time, the air temperature inside the air exchange duct 5 may even be much higher than the outdoor temperature, and the transparency of the photochromic glass 1 may decrease. That is, the temperature of the photovoltaic photochromic facade rises and the light transmittance may decrease. The trend of changes in the building's indoor temperature and light transmittance is the same as that of the photovoltaic photochromic facade.

[0109] When the temperature of the bimetallic strip 3 is above the first deformation temperature, the bimetallic strip 3 begins to deform. The air exchange channel 5 is connected to the outside and air exchange occurs. The air temperature in the air exchange channel 5 will drop, and the photochromic glass 1 may return to a transparent state. That is, the temperature of the photovoltaic photochromic facade drops to the same as the outdoor air temperature, and the light transmittance may increase. The indoor temperature and light transmittance of the building change in the same way as the photovoltaic photochromic facade.

[0110] (2) During a sunny day in the hot summer, the photovoltaic glass 2 generates photovoltaic power, and the photochromic glass 1 reaches its respective opacity peak, exhibiting high reflectivity to visible light:

[0111] The bimetallic sheet 3 deforms, and the air exchange duct 5 remains connected to the outside for air exchange. The temperature inside the air exchange duct 5 is the same as the outdoor air temperature. The photochromic glass 1 not only reflects visible light onto the building but also significantly reduces direct sunlight entering the building's interior. In other words, the photovoltaic photochromic facade has low light transmittance and high reflectivity, reducing indoor lighting and temperature. The reduced indoor temperature is due to the fact that the current photovoltaic photochromic facade not only reduces the heat gained by the entire building from solar radiation but also reduces the temperature rise indoors caused by direct sunlight, further reducing heat exchange between the interior and exterior and reducing the cooling load on the indoor environment in summer.

[0112] When an indoor air system with fresh air is used in summer: the ventilation baffle 4 remains open, and the side of the photochromic glass 1 facing the room is always under positive pressure. The indoor cool air flows into the air exchange duct 5 through the open ventilation baffle 4, and then flows out to the outside from the deformed hot bimetallic sheet 3 at the top of the photovoltaic glass 2. This process effectively utilizes the coldness in the indoor exhaust air to remove excess heat from the air exchange duct 5 while exchanging air, further reducing the temperature of the air exchange duct 5 and improving the photovoltaic power generation efficiency of the photovoltaic glass 2.

[0113] (3) On a clear day during the cold winter, photovoltaic glass 2 generates photovoltaic power, and photochromic glass 1 is transparent and has high light transmittance to visible light:

[0114] The interior has good natural lighting and is relatively warm. Because the photochromic glass 1 is transparent, the interior has good natural lighting. The reason for the relatively warm interior is that the entire building gains heat due to solar radiation; the transparent photochromic glass 1 amplifies the temperature rise caused by direct sunlight; the thermal bimetallic sheet 3 tightly covers the top and bottom of the photovoltaic glass 2, isolating the air exchange duct 5 from the outside. The air temperature inside the air exchange duct 5 rises and exceeds the outside temperature. Regardless of whether the ventilation baffle 4 is open, the higher temperature of the air exchange duct 5 contributes to the overall building's insulation.

[0115] In the thermochromic layer, different mass ratios of thermochromic materials are filled into the vertically arranged photochromic glass 1. This allows all the photochromic glass 1 on each floor of the building to be highly transparent when the ambient temperature is low (e.g., autumn and winter). This does not affect indoor lighting but also ensures that the heat obtained by direct sunlight can be increased, raising the indoor temperature and improving the comfort of the occupants. The entire photovoltaic photochromic facade of the building also plays a role in insulation. In late spring and early summer, not only does the overall air temperature rise, but the outdoor light intensity is also high. Excessive direct sunlight will further increase the indoor temperature and significantly reduce the comfort of the occupants. If the temperature of some photochromic glass 1 exceeds its second color-changing temperature, while the temperature of some photochromic glass 1 is lower than its first color-changing temperature, or between its first and second color-changing temperatures, the vertically arranged photochromic glass 1 on each floor of the building will exhibit different levels of transparency, forming a louver-like shape. Figure 3 As shown in 3a and 3b, segmented shading is implemented; this ensures some indoor lighting while reducing the indoor temperature rise caused by direct sunlight. In the hot summer, the temperature of all photochromic glass 1 exceeds their respective second photochromic temperature, causing all photochromic glass 1 to reach their peak opacity. Photochromic glass 1 has the characteristics of high reflectivity and low light transmittance, such as... Figure 3 As shown in 3c, it blocks a large amount of light from directly entering the room, reducing the indoor temperature rise caused by direct sunlight. It also reduces the heat absorption of the building walls through high reflection, further reducing the heat gained by the building due to solar radiation and lowering the indoor temperature of the building.

[0116] As can be seen from the above analysis, the photovoltaic color-changing facade of this application can make full use of the large area of ​​solar radiation received by the facade to generate photovoltaic power, while adapting to temperature changes throughout the year, automatically regulating the lighting and heat gain of the building interior, and improving the comfort of indoor occupants.

[0117] When the size of the photochromic glass 1 is made too large, resulting in an excessively high vertical height, the lower liquid portion of the thermochromic material colloidal system will experience excessive static pressure. Upon reaching the first color-changing temperature T1, the polymer particles within the thermochromic material aggregate and precipitate. As the temperature of the thermochromic material decreases, the solute concentration at the bottom increases significantly, while the concentration at the top remains relatively low. This causes the entire colloidal system to lose its reversible color-changing properties and exhibit stratification. Therefore, in this application, several pieces of photochromic glass 1 are vertically arranged in the thermochromic layer corresponding to each floor of the building, ensuring that the vertical height of each piece of photochromic glass 1 is not too high. This minimizes the occurrence of stratification and irreversible color changes within the photochromic glass 1. Furthermore, the photochromic glass 1 is filled with thermochromic materials of varying mass ratios. Using this photovoltaic color-changing facade, the personalized lighting needs of different homeowners can be flexibly met, resulting in greater energy savings.

[0118] In existing technologies, drawing curtains can reduce indoor lighting. However, the degree of light blocking by curtains is the same in all areas, and the intensity of direct sunlight in unblocked areas is also the same. Therefore, many homeowners are still bothered by the high intensity of direct sunlight from the lower part of the window even when partially drawing the curtains. Or, even after using curtains to block all direct sunlight, the indoor light is still too dim, requiring indoor lighting. The photovoltaic color-changing facade of this application, when the photovoltaic glass 2 is transparent copper indium gallium selenide photovoltaic glass, and when the color-changing temperature and opacity peak of each piece of color-changing glass are different, can achieve zoned and differentiated shading for the same household, and to a certain extent reduce the use of lighting equipment during the day.

[0119] Example 3

[0120] The stability, uniformity, and reversibility of the thermochromic material are mainly related to its temperature and the vertical height of the encapsulated colloid (i.e., the vertical height of the photochromic glass 1). The photochromic glass 1 must be able to stably, uniformly, and reversibly change color within the local temperature range. This ensures more stable automatic regulation of the photovoltaic photochromic facade's effect on the building's interior lighting and heat gain in Example 2.

[0121] To ensure that each piece of photochromic glass 1 in the photovoltaic color-changing facade can reversibly, uniformly, and stably change color and alter the transparency of the entire glass within the local temperature variation range, thus avoiding the aggregation or precipitation of particles in the thermochromic material, we need to design the dimensions of the photochromic glass in the photovoltaic color-changing facade.

[0122] In thermochromic materials containing 6 wt% hydroxypropyl cellulose, when the sodium chloride concentration is within the range of 0% to 2%, increasing the sodium chloride concentration can significantly reduce the first color change temperature T1 of the thermochromic material.

[0123] This application also provides a design method for photochromic glass on building facades, based on a thermochromic material containing 6 wt% hydroxypropyl cellulose and sodium chloride at concentrations ranging from 0% to 2%, to design the photochromic glass, such as... Figure 4 As shown, it includes the following:

[0124] Based on the homeowner's requirement for the first color-changing temperature T1, the sodium chloride concentration in the thermochromic material was calculated; then, based on the sodium chloride concentration, the upper limit of the height of the photochromic glass 1 when the total potential energy of the thermochromic material is above the stable potential energy threshold was calculated. Ensure that the height of the photochromic glass 1 does not exceed the upper limit of its height. .

[0125] Alternatively, based on the homeowner's preset height for the thermochromic glass 1 on the exterior facade of the floor, calculate the concentration of sodium chloride that should be added to the thermochromic material inside the thermochromic glass 1 when the total potential energy of the thermochromic material is above the stable potential energy threshold.

[0126] The calculation of the sodium chloride concentration in the thermochromic material based on the homeowner's desired initial color-changing temperature T1 also includes the following:

[0127] ;

[0128] in, This indicates the numerical value of sodium chloride concentration.

[0129] The calculation of the total potential energy of thermochromic materials also includes the following:

[0130] ;

[0131] ;

[0132] ; ;

[0133] ;

[0134] ;

[0135] Where H represents the height of photochromic glass 1; T represents the temperature of the thermochromic material, T∈[T3,T4], where T3 and T4 are used to represent the lower and upper limits of the local ambient temperature, respectively; This indicates the height H of the photochromic glass 1, the temperature T of the thermochromic material, and the sodium chloride concentration. The total potential energy of the thermochromic material under the given conditions; This represents the electrostatic repulsion potential energy; Indicates van der Waals strength; Represents pressure potential energy; Pi is a constant. The dielectric constant of the thermochromic material is given; in this application, the dielectric constant of water is 78. This represents the vacuum permittivity, which is taken as 8.854 × 10⁻⁶ in this application. -12 F / m; This represents the particle radius within the thermochromic material colloid, which is taken as 1 × 10⁻⁶ in this application. -6 m; This represents the surface potential; in this application, we use 0.1 V, a typical value applicable to hydrogels. This represents the effective distance between colloidal particles, which is taken as 10 in this application. -6 m; The shielding length is indicated by ; e represents the charge of the electron, which is taken as 1.602 × 10⁻⁶ in this application. -19 Coulomb; I represents ionic strength; The constant represents the Boltzmann constant, which is taken as 1.38 × 10⁻⁶ in this application. -23 J / K; A represents the van der Waals constant, which is taken as 1 × 10⁻⁶ for the hydrogel solution in this application. -21 J / cdotpm; This represents the initial particle spacing, which is 10 in this application. -6 m; This indicates the particle spacing correction, which is set to 10 in this application. -9 m; This represents the adjustment factor used to normalize the pressure effect; in this application, it is set to 0.5. The density of the thermochromic material is indicated. Since the thermochromic material is a colloid with a water content of over 92%, the water density in this application is 1000 kg / m³. This represents the acceleration due to gravity, which is taken as 9.81 m / s² in this application. 2 ; Young's modulus represents the stiffness of a colloid. In this application, the Young's modulus of the hydrogel is taken as 10. 9 Pa.

[0136] The stable potential energy threshold is the critical value at which the thermochromic material remains stable when the photochromic glass is placed vertically. The stable potential energy threshold is denoted as... Based on 6wt% hydroxypropyl cellulose, technicians conducted multiple experiments within the sodium chloride concentration range of 0% to 2%. Through linear fitting and numerical optimization, they obtained the stable potential energy threshold within this sodium chloride concentration range. 10 -21J / cdotpm.

[0137] To maintain the stability, uniformity, and reversibility of the thermochromic material in photochromic glass, given the concentration of sodium chloride in the thermochromic material, we also need to ensure that T, taking any value in [T3, T4], always yields the following result. .

[0138] When T=T3 = , Let be the minimum total potential energy of current thermochromic materials; Then, the upper limit of the height H of the photochromic glass 1 was calculated. .

[0139] Using the design method for photovoltaic color-changing facade glass of this application, within a sodium chloride concentration range of 0% to 2%, based on the homeowner's initial color-changing temperature T1 requirement, the upper limit of the height of the color-changing glass 1 is quickly determined, allowing the color-changing glass 1 to adapt to local temperature changes and achieve uniform, stable, and reversible color changes. The homeowner can also determine several different initial color-changing temperature requirements, and then obtain the upper limit of the height of the color-changing glass 1 corresponding to each of these initial color-changing temperature requirements, as shown below. Figure 2 The diagram shown illustrates the photovoltaic color-changing glass facade. This ensures that each piece of color-changing glass 1 can change color uniformly, stably, and reversibly, while also meeting the homeowner's personalized needs for shading in different areas and to different degrees.

[0140] Because the edges of the photochromic glass 1 will divide the view, if the height of the photochromic glass 1 is too small, the photovoltaic photochromic facade will have too many edges of the photochromic glass 1 that divide the view. If the homeowner has preset the height of the photochromic glass 1, then in order to maintain the stability, uniformity, and reversibility of the color change of the thermochromic material in the photochromic glass, given the height of the photochromic glass 1, we also need to ensure that T, for any value in [T3, T4], has the following properties: .

[0141] When T=T3 = , Let be the minimum total potential energy of current thermochromic materials; The concentration of sodium chloride that should be added to the thermochromic material inside photochromic glass 1 was then determined. Afterwards; if the sodium chloride concentration If the concentration is within the range of 0% to 2%, then the homeowner's current preset height for the tinted glass 1 on their floor can be achieved, and the technicians will adjust the settings according to the current sodium chloride concentration. After manufacturing the thermochromic material, photochromic glass 1 is then manufactured according to the homeowner's desired height; if the sodium chloride concentration... If the desired height is outside the 0% to 2% range, the homeowner's current preset height for the photochromic glass 1 on their floor will not be adopted. This means the homeowner's current height requirement for the photochromic glass 1 on their floor may prevent the glass from changing color stably, uniformly, and reversibly in the future. In this case, the homeowner needs to reduce the preset height of the photochromic glass 1 on their floor and then recalculate the sodium chloride concentration. until the sodium chloride concentration It is within the range of 0% to 2%.

[0142] Using the design method for photovoltaic color-changing facade glass of this application, it is possible to quickly determine whether stable, uniform, and reversible color-changing glass exists within a sodium chloride concentration range of 0% to 2%, based on the homeowner's preset height for the color-changing glass. If not, the homeowner needs to lower the preset height of the color-changing glass 1 on their floor until it is determined that stable, uniform, and reversible color-changing glass exists within the 0% to 2% sodium chloride concentration range. Subsequently, thermochromic materials and color-changing glass 1 corresponding to the sodium chloride concentration are produced and installed. This not only ensures that the color-changing glass on the homeowner's floor can change color stably, but also ensures that the height of the color-changing glass on the homeowner's floor is as large as possible, giving the homeowner a better viewing experience. Moreover, it eliminates the need to spend a lot of time conducting color-changing stability tests on the color-changing glass at different temperatures, saving a lot of manpower and resources and improving the production efficiency of the color-changing glass 1.

[0143] The technologies, shapes, and structures not described in detail in this embodiment are all well-known technologies. It should also be noted that the above are merely preferred embodiments created in this embodiment and are not intended to limit the creation of this embodiment. Each component or step in this embodiment can be decomposed and / or recombined, and these decompositions and / or recombinations should be considered as equivalent solutions of this application and should all fall within the protection scope of this application.

Claims

1. A photovoltaic color-changing facade, characterized in that, include: A photovoltaic layer and a thermochromic layer are installed on the outside of the building. The photovoltaic layer faces the outside and the thermochromic layer faces the inside. The thermochromic layer includes several adjacent and closely arranged photochromic glasses (1), and the photovoltaic layer includes several adjacent and closely arranged photovoltaic glasses (2). The photochromic glass (1) includes a transparent encapsulation shell and a thermochromic material. The thermochromic material is located inside the transparent encapsulation shell. The thermochromic material is a colloid composed of hydroxypropyl cellulose and sodium chloride as solutes and distilled water as solvent. When the temperature of the thermochromic material is lower than the first color change temperature T1, the thermochromic material is colorless and transparent. When the temperature of the thermochromic material reaches the first color change temperature T1, the thermochromic material gradually turns into a white and opaque state. When the thermochromic material is above the second color change temperature T2, the opacity of the thermochromic material is its own opacity peak value. 0 < T1 < T2. The thermochromic material is a colloid composed of 6 wt% hydroxypropyl cellulose, sodium chloride, and distilled water; Based on the sodium chloride concentration within the range of 0% to 2%, the photochromic glass is designed as follows: the sodium chloride concentration in the thermochromic material is calculated according to the first color-changing temperature T1; then, based on the sodium chloride concentration, the upper limit of the height of the photochromic glass (1) when the total potential energy of the thermochromic material is above the stable potential energy threshold is calculated. ; Ensure that the height of the photochromic glass (1) does not exceed the upper limit of its height. ; Alternatively, based on the preset height of the thermochromic glass (1) on the exterior facade of the floor, calculate the concentration of sodium chloride that should be added to the thermochromic material in the thermochromic glass (1) when the total potential energy of the thermochromic material is above the stable potential energy threshold. Based on the required first color-changing temperature T1, the sodium chloride concentration in the thermochromic material is calculated, including: ;in, This indicates the numerical value of sodium chloride concentration; Calculate the total potential energy of the thermochromic material, including the following: ； ； ； ； ； ； Wherein, H represents the height of the photochromic glass (1); T represents the temperature of the thermochromic material; The height H of the photochromic glass (1), the temperature T of the thermochromic material, and the sodium chloride concentration are indicated. The total potential energy of the thermochromic material under the given conditions; This represents the electrostatic repulsion potential energy; Indicates van der Waals strength; Represents pressure potential energy; This indicates the numerical value of sodium chloride concentration; Pi is a constant. This represents the dielectric constant of the thermochromic material colloid. Represents the vacuum permittivity; Indicates the particle radius of thermochromic materials; Indicates surface potential; Indicates the effective distance between colloidal particles; Indicates the shielding length; e represents the electron charge; I represents the ionic strength; Denotes Boltzmann constant; A denotes van der Waals constant; Indicates the initial particle spacing; Indicates particle spacing correction; Indicates the adjustment factor; Indicates the density of thermochromic materials; Represents gravitational acceleration; This represents Young's modulus.

2. The photovoltaic color-changing facade according to claim 1, characterized in that: A bimetallic strip (3) is provided at the top and bottom of the photovoltaic glass (2); the space between the photovoltaic glass (2) and the photochromic glass (1) is the air exchange channel (5); when the temperature of the bimetallic strip (3) is lower than the first deformation temperature, the bimetallic strip (3) covers the top and bottom of the photovoltaic glass (2) and isolates the air exchange channel (5) from the outside; when the temperature of the bimetallic strip (3) is higher than the first deformation temperature, the bimetallic strip (3) curls up towards the outside and the air exchange channel (5) connects with the outside.

3. The photovoltaic color-changing facade according to claim 1, characterized in that: The top and bottom of the photochromic glass (1) are equipped with ventilation baffles (4); the opening or closing of the ventilation baffles (4) allows the air exchange duct (5) to be connected to or isolated from the room.

4. A photovoltaic color-changing facade according to claim 1, characterized in that, The process of making photochromic glass (1) includes the following steps: S1, Assemble and fix transparent tempered glass into a rectangular cavity with an injection port; S2, After filling the rectangular cavity with the prepared thermochromic material through the injection port, the injection port is sealed; the rectangular cavity with the injection port sealed is the transparent encapsulation shell; S3, after the transparent encapsulation shell filled with thermochromic material is left to stand for several hours, the photochromic glass (1) is obtained.

5. A photovoltaic color-changing facade according to claim 4, characterized in that: S1 also includes S11~S13: S11, Place a piece of tempered high-transparency glass horizontally, use double-sided nano tape as an adhesive, and stick it along the outer edge of the upper surface of the tempered high-transparency glass until a break of length L is left. S12, place another identical piece of tempered high-transparency glass horizontally onto the surface of the tempered high-transparency glass that has been covered with double-sided nano-adhesive tape, and then press it down; the joints on the sides of the two pieces of tempered high-transparency glass where the adhesive is missing are the injection ports. S13, wait for the adhesive to completely solidify to obtain a rectangular cavity; In S2: Place the rectangular cavity vertically with the side containing the injection port facing upwards. Use a needle syringe to fill the rectangular cavity with the prepared thermochromic material, and immediately seal the injection port with sealant. Then place the transparent encapsulation shell filled with thermochromic material horizontally. The preparation of thermochromic materials also includes S1´~S3´: S1´, hydroxypropyl cellulose, sodium chloride and distilled water are mixed in a set mass ratio to obtain a mixture; S2´, the mixture is stirred evenly for 48 hours at a speed of 200 rpm; S3´, let the stirred mixture stand until there are no more air bubbles in the mixture. At this point, the mixture is the thermochromic material.

6. A photovoltaic color-changing facade according to any one of claims 1-5, characterized in that: Photovoltaic glass (2) is transparent copper indium gallium selenide photovoltaic glass, which generates photovoltaic power due to the irradiation of outdoor light.

7. A photovoltaic color-changing facade according to any one of claims 1-5, characterized in that: The photovoltaic glass (2) is a double-sided photovoltaic glass. The double-sided photovoltaic glass is composed of two pieces of glass and a double-sided photovoltaic power generation panel. The double-sided photovoltaic power generation panel is located between the two pieces of glass. One side of the double-sided photovoltaic glass generates photovoltaic power due to the irradiation of outdoor light, and the other side of the double-sided photovoltaic glass generates secondary photovoltaic power due to the reflected light from the color-changing glass (1).

8. A photovoltaic color-changing facade according to claim 7, characterized in that: When T is the lower limit of the local ambient temperature T3, let The upper limit of the height of the photochromic glass (1) was then calculated. ;in, This represents the stable potential energy threshold; Or, when T=T3, let The concentration of sodium chloride that should be added to the thermochromic material in the photochromic glass (1) was then determined. Among them, if the sodium chloride concentration If it is within the range of 0% to 2%, then it should be based on the current sodium chloride concentration. After producing the thermochromic material, photochromic glass is then produced at a preset height (1); if the sodium chloride concentration If the value is outside the 0% to 2% range, the current preset height for the photochromic glass (1) on the exterior facade of the floor is not adopted; after reducing the preset height for the photochromic glass (1) on the exterior facade of the floor, the sodium chloride concentration is recalculated. until the sodium chloride concentration It is within the range of 0% to 2%.

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