Design method of building facade photochromic glass

Abstract

The invention belongs to the technical field of building facades, and particularly relates to a design method of building facade photochromic glass. The design method comprises the steps that the photochromic glass comprises a transparent packaging shell and a thermochromic material, and the thermochromic material is located in the transparent packaging shell; the thermochromic material is a colloid formed by 6wt% of hydroxy propyl cellulose, sodium chloride and distilled water; designing the photochromic glass based on the sodium chloride concentration within the range of 0-2%: calculating the sodium chloride concentration in the thermochromic material according to the first color change temperature; calculating the height upper limit of the photochromic glass when the total potential energy of the thermochromic material is above a stable potential energy threshold value based on the sodium chloride concentration; the height of the photochromic glass does not exceed the height upper limit. The reversible and uniform photochromic glass capable of automatically and stably changing the transparency according to the temperature can be designed, and indoor light in summer can be stably regulated and controlled.

Description

Technical Field

[0001] This application belongs to the field of building facade technology, and in particular relates to a design method for color-changing glass for building facades. 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 people's normal work (for example, the light is so strong that even a bright screen is hard to see) and cause the indoor temperature to become too high, placing a huge burden on the cooling system.

[0005] People often use curtains to reduce direct sunlight in summer. However, the degree of light blocking by curtains is the same in the areas that are not blocked, and the intensity of direct sunlight in the unblocked areas is also the same. If only part of the curtains are drawn, the windows that are not covered by curtains will still let in strong direct sunlight. When the windows are open, the curtains may be blown by the wind and may not be able to block light stably. Therefore, the effect and stability of using curtains to regulate indoor light in summer is not good. Summary of the Invention

[0006] The purpose of this application is to overcome the shortcomings of the prior art and provide a design method for color-changing glass on building facades. This method can design color-changing glass that is reversible, uniform, and automatically and stably changes color and transparency according to temperature changes, thereby reducing direct sunlight entering the room in summer and stably regulating indoor light in summer.

[0007] To achieve the above objectives, this application adopts the following technical solution: A design method for photochromic glass on building facades includes the following: the photochromic glass comprises a transparent encapsulation shell and a thermochromic material, the thermochromic material being located inside the transparent encapsulation shell; the thermochromic material is a colloid composed of 6 wt% hydroxypropyl cellulose, sodium chloride, and distilled water; the photochromic glass is designed based on a sodium chloride concentration within the range of 0% to 2%: the sodium chloride concentration in the thermochromic material is calculated according to the first color-changing temperature T1 requirement; and based on the sodium chloride concentration, the upper limit of the height of the photochromic glass when the total potential energy of the thermochromic material is above the stable potential energy threshold is calculated. Ensure the height of the photochromic glass does not exceed the upper limit. .

[0008] Preferably, or, based on the preset height of the thermochromic glass on the exterior facade of the floor, the concentration of sodium chloride to 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 is calculated.

[0009] Preferably, 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.

[0010] 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, H represents the stable potential energy threshold; T represents the height of the photochromic glass; and 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.

[0011] Preferably, when T=T3, let The concentration of sodium chloride that should be added to the thermochromic material inside the photochromic glass was then determined. ;in, H represents the stable potential energy threshold; T represents the height of the photochromic glass; and 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 following conditions; if the sodium chloride concentration is... 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%.

[0012] Preferably, the calculation of the total potential energy of the thermochromic material includes the following: ; ; ; ; ; ; in, 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.

[0013] Preferably, when the temperature of the thermochromic material is below the 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 the second color-changing temperature T2, the opacity of the thermochromic material is its own opacity peak value; 0 < T1 < T2.

[0014] The beneficial effects of this application are as follows: (1) A design method for color-changing glass on building facades, which can design color-changing glass that is reversible, uniform and automatically and stably changes color and changes transparency according to temperature changes, reduces direct sunlight entering the room in summer, and stably regulates indoor light in summer; avoids the occurrence of layered color change and irreversible color change in color-changing glass.

[0015] (2) The design method of photochromic glass for building facades of this application allows for the rapid determination of the upper limit of the photochromic glass height based on the homeowner's first color-changing temperature requirement within a sodium chloride concentration range of 0% to 2%. This enables the photochromic glass to adapt to local temperature changes and change color uniformly, stably, and reversibly. Homeowners can also determine several different first color-changing temperature requirements and then obtain the upper limit of the photochromic glass height corresponding to each of these first color-changing temperature requirements. This ensures that each piece of photochromic glass can change color uniformly, stably, and reversibly, while also fulfilling the homeowner's personalized needs for shading by area and degree.

[0016] (3) The design method for a building facade photochromic glass of this application can quickly determine whether there is photochromic glass that can stably, uniformly, and reversibly change color within the sodium chloride concentration range of 0% to 2% based on the homeowner's preset photochromic glass height. If not, the homeowner needs to lower the preset height of the photochromic glass on the facade of their floor until it is determined that there is photochromic glass that can stably, uniformly, and reversibly change color within the sodium chloride concentration range of 0% to 2%. Subsequently, thermochromic materials and photochromic glass of the corresponding sodium chloride concentration are produced and installed. This not only ensures that the photochromic glass on the facade of the homeowner's floor can stably change color, but also ensures that the height of the photochromic 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 photochromic glass at different temperatures, saving a lot of manpower and resources and improving the production efficiency of photochromic glass.

[0017] (4) The color-changing facade of the building obtained by the design method of this application can adapt to the temperature changes of the four seasons and automatically regulate the lighting and heat gain of the building interior, thereby improving the comfort of the people inside. Especially in the hot summer, it can automatically become in a state of not being completely transparent or opaque, reducing the indoor lighting rate, avoiding direct sunlight on the interior, and significantly reducing the heat gain caused by direct sunlight, further reducing the indoor temperature and improving indoor comfort.

[0018] (5) The color-changing facade of the building obtained by the design method of this application 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. Furthermore, the opening method of the inward-tilting window or the outward-tilting window not only ensures indoor ventilation, but also does not affect the adjustment of indoor light by the color-changing glass, that is, it further ensures the stability of the adjustment of indoor light by the color-changing glass under ventilation.

[0019] (6) The process of making the color-changing facade of the building obtained by the design method of this application is simple and can make color-changing glass conveniently and at low cost; it also improves the stability and color uniformity of the internal thermochromic material when the color-changing glass is placed vertically afterward by reducing the thickness of the inner cavity of the transparent encapsulation shell; it reduces the amount of thermochromic material filled into the color-changing glass and saves costs. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating a method for manufacturing photochromic glass according to this application; Figure 2 A schematic diagram of the color-changing glass on the exterior facade corresponding to each floor of the building; Figure 3 A schematic diagram of the exterior facade of each floor of the building at different temperatures; Figure 4 A schematic diagram showing photochromic glass fixed in a transparent slot structure; Figure 5 This is a flowchart illustrating a design method for photochromic glass on building facades according to this application. Detailed Implementation

[0021] 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.

[0022] A color-changing facade for a building includes several adjacent and closely arranged color-changing glass panes 1 disposed on the exterior of the building.

[0023] Photochromic glass 1 includes a transparent encapsulation shell and a thermochromic material filled inside it. 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.

[0024] As a color-changing facade for buildings, the color-changing glass has one side of its transparent enclosure facing the outside and the other side facing the inside.

[0025] 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.

[0026] Optionally, in the thermochromic material, the mass ratio of hydroxypropyl cellulose, sodium chloride, and distilled water is 3:1:46.

[0027] The manufacturing method of photochromic glass 1, as follows: Figure 1 As shown, it includes the following: S1, assemble and fix tempered high-transparency 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 thermochromic glass is obtained.

[0028] S1 also includes the following: 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 fully solidify to obtain a rectangular cavity.

[0029] The structure on the side of the rectangular cavity, excluding the injection port, consists of "tempered high-transparency glass - adhesive - tempered high-transparency glass".

[0030] In this embodiment, the thickness of the double-sided nano-adhesive used as an adhesive is 1mm, that is, the gap between the two pieces of high-transparency tempered glass is 1mm; 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.

[0031] The preparation of thermochromic materials also includes the following: 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 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; 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.

[0032] Thermochromic materials begin to show a significant change in color and transparency when their temperature reaches the first color-changing temperature T1.

[0033] 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.

[0034] 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.

[0035] 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%.

[0036] Optionally, thermochromic materials may also include gellan gum. Gellan gum can further enhance the stability of thermochromic materials.

[0037] In this embodiment, the weight percentage of gellan gum in the thermochromic material is 5 wt%.

[0038] 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.

[0039] S2 also includes the following: 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.

[0040] The structure on the side of the rectangular cavity at the sealed injection port is "tempered high-transparency glass - sealant - tempered high-transparency glass".

[0041] In S3, the settling time is 24 hours.

[0042] 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.

[0043] The photochromic glass 1 described in this application can not only be used to form the exterior facade of a building, but also as a window, which can automatically adjust the indoor lighting in summer through its thermochromic properties.

[0044] This application also provides a color-changing facade for a building, comprising: a plurality of adjacent and closely arranged color-changing glass panes 1 on the exterior of the building.

[0045] 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 needs of different homeowners and make the automatic adjustment of the building's color-changing facade for the lighting of different interiors of the building more personalized.

[0046] Optional, such as Figure 2 As shown, several pieces of photochromic glass 1 are vertically installed on the exterior facade corresponding to each floor of the building, and the several pieces of photochromic glass 1 corresponding to each floor of the building are filled with thermochromic materials of different mass ratios.

[0047] Optional, such as Figure 4 As shown, the photochromic glass 1 is fixedly engaged in a transparent slot structure set on the exterior of the building. Compared to traditional glass facades where the glass is installed between beams and columns, this not only makes the photochromic glass 1 more securely installed, but also ensures that if the photochromic glass breaks, it will not shatter and injure people inside the building, and it is also easier for installers to carry out the installation.

[0048] This application discloses a color-changing building facade that automatically adjusts its light transmittance according to temperature changes. In the hot summer, it 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.

[0049] For the several pieces of photochromic glass 1 vertically installed on the exterior facade of each floor of this application, different mass ratios of thermochromic materials are filled into different photochromic glass 1. This makes all the photochromic glass 1 corresponding to each floor of the building 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 building facade also plays a role in heat preservation. 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, significantly reducing the comfort of the occupants. In this application, the ambient temperature is higher than the second color-changing temperature of some photochromic glass, lower than the first color-changing temperature of some photochromic glass, or between the first and second color-changing temperatures of some photochromic glass. This will cause the photochromic glass 1 vertically installed on each floor of the building to exhibit different transparency, forming a louver-like shape, such as... Figure 3 As shown in 3a and 3b, segmented shading is implemented; this ensures some natural light indoors while reducing the indoor temperature rise caused by direct sunlight. In the hot summer, the ambient temperature exceeds the second color-changing temperature of all photochromic glass 1 on each floor of the building, causing all photochromic glass 1 to reach its 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 shining directly into 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 lowering the indoor temperature of the building.

[0050] As can be seen from the above analysis, the color-changing facade of the building in this application can adapt to temperature changes throughout the year, automatically regulate the lighting and heat gain of the building interior, and improve the comfort of indoor occupants.

[0051] 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 lower part increases significantly, while the solute concentration at the upper part remains relatively low. This causes the entire colloidal system of the thermochromic material to lose its reversible color-changing properties and exhibit stratification. Therefore, this application uses several pieces of photochromic glass 1 vertically arranged on the exterior facade of each floor, ensuring that each piece is not too high in the vertical direction. This minimizes the possibility of stratification and irreversible color changes within the photochromic glass 1.

[0052] By reducing the maximum static pressure inside the lower part of the thermochromic material colloid, the probability of uneven color change in a single piece of thermochromic glass 1 in the vertical direction is avoided, thereby improving the color change uniformity and stability of each piece of thermochromic glass 1.

[0053] The present application provides a number of photochromic glass panels 1 installed vertically on the exterior facade of each floor of the building, and the photochromic glass panels 1 are filled with thermochromic materials of different mass ratios; that is, by using a photochromic building facade of the present application, the personalized needs of different homeowners for the degree of lighting can be flexibly met, and energy saving can be achieved.

[0054] 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 strong 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 additional indoor lighting. The photochromic glass used in this application, however, with its varying color-changing temperature and peak opacity of each pane, allows for zoned and differentiated light blocking for the same resident, reducing the need for daytime lighting to some extent. Furthermore, the inward or outward opening of windows ensures indoor ventilation without affecting the photochromic glass's ability to regulate indoor light. With curtains, regardless of the opening method, ventilation causes the curtains to be blown about, making their control over indoor light unstable.

[0055] 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.

[0056] The photochromic glass 1 in this application can also be used to make windows.

[0057] The stability, uniformity, and reversibility of thermochromic materials are mainly related to the temperature of the thermochromic material and the vertical height of the encapsulated colloid (i.e., the vertical height of photochromic glass 1). Photochromic glass must be able to change color stably, uniformly, and reversibly within the local temperature variation range.

[0058] To ensure that each piece of photochromic glass in the building facade can reversibly, uniformly, and stably change color and alter the transparency of the entire glass within the local temperature range, and to prevent the aggregation or precipitation of particles in the thermochromic material, we need to design the dimensions of the photochromic glass.

[0059] 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.

[0060] 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 5 As shown, it includes the following: 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. .

[0061] 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.

[0062] 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: ; in, This indicates the numerical value of sodium chloride concentration.

[0063] The calculation of the total potential energy of thermochromic materials also includes the following: ; ; ; ; ; ; 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; (T, H) represents the height H of the photochromic glass 1, the temperature T of the thermochromic material, and the concentration of sodium chloride. 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.

[0064] 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. 10-21 J / cdotpm.

[0065] 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 desired result. .

[0066] 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. .

[0067] Using the design method for photochromic glass on building facades according to this application, within a sodium chloride concentration range of 0% to 2%, based on the homeowner's initial photochromic temperature requirement T1, the upper limit of the height of the photochromic glass 1 is quickly determined, allowing the photochromic glass 1 to adapt to local temperature changes and achieve uniform, stable, and reversible photochromic changes. The homeowner can also determine several different initial photochromic temperature requirements, and then obtain the upper limit of the height of the photochromic glass 1 corresponding to each of these initial photochromic temperature requirements, as shown below. Figure 2 The diagram shown illustrates the color-changing glass on the exterior 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 varying degrees.

[0068] Because the edges of the photochromic glass 1 will divide the view, if the height of the photochromic glass 1 on the exterior facade is too small, there will be too many edges of the photochromic glass 1 on the building facade that divide the view. If the homeowner has preset the height of the photochromic glass 1 on the exterior facade of their floor, 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: .

[0069] 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 the exterior facade of their floor can be achieved, according to the technicians based on 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 the exterior facade of 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 1 from changing color stably, uniformly, and reversibly in the future. Therefore, 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%.

[0070] Using the design method for photochromic glass on building facades according to this application, it is possible to quickly determine whether photochromic glass exists within a sodium chloride concentration range of 0% to 2%, based on the homeowner's preset height for the photochromic glass. If not, the homeowner needs to lower the preset height of the photochromic glass 1 on their floor until it is determined that photochromic glass exists within the 0% to 2% sodium chloride concentration range. Subsequently, thermochromic materials and photochromic glass 1 corresponding to the sodium chloride concentration are produced and installed. This not only ensures that the photochromic glass on the homeowner's floor can stably change color, but also ensures that the height of the photochromic glass on the homeowner's floor is as large as possible, providing the homeowner with a better viewing experience. Moreover, it eliminates the need to spend a lot of time conducting color-changing stability tests on the photochromic glass at different temperatures, saving a significant amount of manpower and resources and improving the production efficiency of the photochromic glass 1.

[0071] 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 design method for photochromic glass on building facades, characterized in that, Includes the following: Photochromic glass (1) includes a transparent encapsulation shell and a thermochromic material, the thermochromic material being located inside the transparent encapsulation shell; the thermochromic material is a colloid composed of 6wt% 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. .

2. The design method for photochromic glass on building facades according to claim 1, characterized in that: 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.

3. The design method for photochromic glass on building facades according to claim 1, characterized in that, 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.

4. The design method for photochromic glass on building facades according to claim 3, 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, H represents the stable potential energy threshold; T 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.

5. The design method for photochromic glass on building facades according to claim 2, characterized in that: 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. ;in, H represents the stable potential energy threshold; T 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; If 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 the thermochromic material is made, the photochromic glass is made according to the preset height (1). If 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%.

6. A design method for photochromic glass on building facades according to claim 4 or 5, characterized in that, Calculate the total potential energy of the thermochromic material, including the following: ； ； ； ； ； ； in, 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.

7. The design method for photochromic glass on building facades according to claim 6, characterized in that: When the temperature of the thermochromic material is below the 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 turns into a white and opaque state; when the temperature of the thermochromic material is above the second color-changing temperature T2, the opacity of the thermochromic material is its own opacity peak value; 0 < T1 < T2.

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