Energy-saving film based on solar spectrum radiation regulation and control and spectral characteristic calculation method thereof

Abstract

The invention provides an energy-saving film based on solar spectrum radiation regulation and a spectral characteristic calculation method thereof. The energy-saving film comprises a substrate, a first film layer, a second film layer, a third film layer, a fourth film layer and a fifth film layer which are sequentially connected from top to bottom. The optical performance of the energy-saving thin film is superior to that of Low-E glass, the energy-saving effect is better, and the preparation efficiency is high; film layers are tightly combined, the film forming effect is good, the property is stable and reliable, and long-term use can be realized; the device can be flexibly applied to buildings without being integrally manufactured with glass, and is also suitable for approximately closed spaces such as greenhouses and automobiles; the device is simple in arrangement, convenient to install, foldable in later period and huge in popularization potential.

Description

Technical Field

[0001] The invention relates to the field of processing and preparing composite material specimens, and in particular to an energy-saving film based on solar spectrum radiation regulation and a method for calculating its spectral characteristics. Background Art

[0002] The material life of today's human society is changing with each passing day, and a large number of social production activities are supported by energy. In recent years, energy consumption has increased dramatically, and the reserves of traditional energy represented by coal and charcoal are becoming increasingly depleted. The environmental damage caused by these energy sources during use has become a social problem that needs to be solved urgently.

[0003] Among the many energy consumption channels, building energy consumption always accounts for a large proportion. Among the many sources of building energy consumption, space temperature regulation energy consumption accounts for about 50% of the total building energy consumption. Faced with such a large amount of energy consumption, it is necessary to develop effective building space temperature regulation energy-saving technology11. The basic idea of ​​this application is to efficiently utilize green new energy and reduce the consumption of traditional energy.

[0004] Green energy includes hydropower, wind power, solar energy, etc. Among them, solar energy is the most abundant energy available to humans. Its energy is mainly distributed in visible light (43%) and near-infrared bands (52%), and a very small part exists in the ultraviolet band (5%). About 2 / 3 of the regions in my country have an annual sunshine time of more than 2200 hours and an annual radiation amount of more than 5016MJ / m 2 , with natural energy location advantages. Therefore, how to reasonably and efficiently utilize solar energy is a scientific and engineering issue of great practical significance. At present, the way to regulate the temperature of building space is still mainly based on the large-scale consumption of traditional energy. Based on this situation, it is of great significance to implement technical means to reduce the consumption of traditional energy and the efficient use of new energy in parallel. Summary of the invention

[0005] In order to solve the above problems, the present invention provides an energy-saving film based on solar spectrum radiation regulation and a method for calculating its spectral characteristics, so as to apply the energy-saving film to ordinary glass and reasonably regulate solar radiation. The film is based on a three-layer structure of dielectric-metal-dielectric. Through a large number of tests and comparisons, a five-layer structure of double dielectric-metal-double dielectric is innovatively designed. This structure has high transmittance in the visible light band, low transmittance in the near-infrared band, and extremely high reflectivity in the mid- and far-infrared bands. This spectral characteristic enables the glass to which the film is applied to fully transmit visible light while reducing the escape of indoor mid- and far-infrared radiation in winter, and inhibiting the entry of outdoor near-infrared radiation in summer, thereby reducing the consumption of indoor heating or cooling energy and achieving energy-saving effects.

[0006] To achieve the above object, the present invention provides an energy-saving thin film based on solar spectral radiation regulation and a calculation method for its spectral characteristics. The technical solution adopted is as follows:

[0007] According to the first technical solution of the present invention, there is provided an energy-saving thin film based on solar spectral radiation regulation, including a substrate, a first film layer, a second film layer, a third film layer, a fourth film layer, and a fifth film layer connected in sequence from top to bottom.

[0008] Further, the first film layer and the fifth film layer are SiO2.

[0009] Further, the thickness of the first film layer is 70 - 75 nm, and the thickness of the fifth film layer is 8 - 10 nm.

[0010] Further, the second film layer and the fourth film layer are ZnSe.

[0011] Further, the thickness of the second film layer is 23 - 25 nm, and the thickness of the fourth film layer is 21 - 23 nm.

[0012] Further, the third film layer is Ag.

[0013] Further, the thickness of the third film layer is 20 - 22 nm.

[0014] Further, the substrate is K9 glass.

[0015] According to the second technical solution of the present invention, there is provided a calculation method for the spectral characteristics of the above-mentioned energy-saving thin film based on solar spectral radiation regulation. The method includes:

[0016] When light with a wavelength of λ is incident on the energy-saving thin film at an angle of θ, it is determined that the tangential components of the electric field and magnetic field of the l-th layer are E l and H l , and the tangential components of the electric field and magnetic field of the (l + 1)-th layer are E l+1 and H l+1 , E l and H l and E l+1 and H l+1 The relationship between them is expressed as:

[0017]

[0018] where M l represents the characteristic matrix of the l-th layer medium and is expressed as:

[0019]

[0020] where δ l is the effective phase thickness of the l-th layer, and d l are the refractive index and thickness of the l-th layer of the medium, respectively, and θ l represents the incident light angle of the l-th layer; j represents the imaginary unit,

[0021] represents the refraction angle of the l-th layer of the medium, satisfying Snell's law of refraction;

[0022] When the number of thin films is k, the total characteristic matrix M is expressed as:

[0023]

[0024] Denote M as The reflectivity R of the incident light is expressed as:

[0025]

[0026] where, m 11 、m 12 、m 21 、m 22 represent the four elements of the matrix, and η0 and η k+1 represent the admittances of the first layer and the (k + 1)-th layer, respectively;

[0027] The absorptivity T of the incident light is expressed as:

[0028]

[0029] where, Re represents taking the real part of the complex number;

[0031] Furthermore, the method further includes:

[0032] Under the condition of thermal equilibrium, the relationship between the emissivity ε and the absorptivity A of the incident light is expressed as:

[0033] ε = A

[0034] Without considering the projection, the reflectivity R of the incident light is expressed as:

[0035] R = 1 - A = 1 - ε

[0037] The present invention has at least the following beneficial effects:

[0038] 1) The energy-saving thin film provided by the present invention has a five-layer structure of double dielectric-metal-double dielectric, and its performance is superior to that of common Low-E glass in each wave band.

[0039] 2) The present invention uses the magnification factor to adjust the coating rate, the film layers are tightly combined, the film-forming effect is good, and the properties are stable and reliable.

[0040] 3) The energy-saving film provided by the present invention can achieve reasonable regulation of solar radiation, meet the efficient utilization of green new energy, and achieve the technical purpose of reducing the consumption of traditional energy. In winter, the ordinary glass applied with this film can effectively reduce the medium and far-infrared radiation escaping outdoors through glass doors and windows, reducing the heating energy consumption indoors; in summer, the near-infrared radiation from outdoors is effectively blocked, reducing the cooling energy consumption indoors. The high transmittance in the visible light band ensures the daily use function of the glass. Compared with the widely used Low-E glass at present, this film exhibits better optical performance, achieves better energy-saving effects, and can be flexibly applied to doors and windows without the need for integrated manufacturing with glass, having the potential for large-scale promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to actual scale.

[0042] Figure 1 Shows a schematic structural diagram of an energy-saving film based on solar spectral radiation regulation according to an embodiment of the present invention.

[0043] Figure 2 Shows the reflection spectral curve of the film according to an embodiment of the present invention.

[0044] Figure 3 Shows the transmission spectral curve of the film according to an embodiment of the present invention.

[0045] Figure 4 Shows the absorption spectral curve of the film according to an embodiment of the present invention.

[0046] Figure 5 Shows a schematic diagram of the application of the energy-saving film in a rigid substrate state according to an embodiment of the present invention.

[0047] Figure 6 Shows a schematic diagram of the application of the energy-saving film in a flexible substrate state according to an embodiment of the present invention.

[0048] Figure 7 Shows the mid-infrared band thermal imaging effect diagram according to an embodiment of the present invention.

[0049] Figure 8 Shows the far-infrared band thermal imaging effect diagram according to an embodiment of the present invention.

[0050] Reference numerals: 100, substrate; 200, first film layer; 300, second film layer; 400, third film layer; 500, fourth film layer; 600, fifth film layer. Detailed implementation manners

[0051] The following describes the implementation manners of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0052] In the description of the present invention, unless otherwise specified, "a plurality of" means two or more; the orientation or positional relationships indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present invention. In addition, terms such as "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0053] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0054] The following further describes the specific implementation manners of the present invention in detail with reference to the drawings and embodiments.

[0055] The traditional dielectric-metal-dielectric three-layer thin film structure can achieve high transmittance in the visible light band and high reflectance in the mid- and far-infrared bands. Based on this idea and combined with the energy-saving requirements of space temperature regulation, the three-layer structure is adjusted. After a large number of experiments, the embodiments of the present invention propose an energy-saving thin film based on solar spectral radiation regulation. As Figure 1 shown, it is a schematic structural diagram of the energy-saving thin film. The energy-saving thin film based on solar spectral radiation regulation includes a substrate 100, a first film layer 200, a second film layer 300, a third film layer 400, a fourth film layer 500, and a fifth film layer 600, which are connected in sequence from top to bottom.

[0056] In this embodiment, the first film layer and the fifth film layer are SiO2, where the thickness of the first film layer is 70 - 75 nm, and the thickness of the fifth film layer is 8 - 10 nm.

[0057] In this embodiment, the second film layer and the fourth film layer are ZnSe, where the thickness of the second film layer is 23 - 25 nm, and the thickness of the fourth film layer is 21 - 23 nm.

[0058] In this embodiment, the third film layer is Ag, and the thickness of the third film layer is 20 - 22 nm.

[0059] In this embodiment, the substrate is K9 glass.

[0060] In this embodiment, three materials, namely silicon dioxide (SiO2), zinc selenide (ZnSe), and silver (Ag), are selected for design. The 3 - layer thin film is extended to 5 layers, meeting the energy - saving requirements in the visible light, near - infrared, and mid - to - far - infrared bands. Moreover, the thickness of each layer of material takes into account both the preparation efficiency and the performance manifestation. In the selection of preparation conditions, this embodiment designs a unique magnification factor for each material to adjust the plating rate, and this technology further ensures the quality and efficiency of sample production. The detailed film layer data and structure are shown in Table 1, Figure 1 as shown below.

[0061] Table 1 Film Layer Data

[0062] Coating layer serial number Substrate First coating layer Second coating layer Third coating layer Fourth coating layer Fifth coating layer Material type K9 glass <![CDATA[SiO2]]> ZnSe Ag ZnSe <![CDATA[SiO2]]> Thickness / nm 73.63 23.97 21.40 22.09 8.85

[0063] The advantages of this energy - saving thin film are as follows:

[0064] (1) The performance of the thin - film spectrum in the visible light, near - infrared, and mid - to - far - infrared bands is superior to that of common Low - E glass;

[0065] (2) The structure should have a smaller total number of film layers, appropriate single - layer thickness, and higher plating efficiency.

[0066] The embodiment of the present invention also proposes a Figure 1 method for calculating the spectral characteristics of an energy - saving thin film based on solar spectrum radiation regulation with the structure shown below. The method includes:

[0067] When light with a wavelength of λ is incident on the energy - saving thin film at an angle of θ, determining that the tangential components of the electric field and magnetic field of the l - th layer are E l and H l , and the tangential components of the electric field and magnetic field of the (l + 1) - th layer are E l+1 and H l+1 , and the relationship between E l and H l and E l+1 and H l+1 is expressed as:

[0068]

[0069] where M l represents the characteristic matrix of the l-th layer of medium, expressed as:

[0070]

[0071] where δ l represents the effective phase thickness of the l-th layer, and d l are the refractive index and thickness of the l-th layer of medium respectively, θ l represents the incident light angle of the l-th layer; j represents the imaginary unit,

[0072] represents the refraction angle of the l-th layer of medium, satisfying Snell's law of refraction: n l sinθ l =n l-1 sinθ l-1 =n0sinθ0.

[0073] When the number of thin films is k, the total characteristic matrix M is expressed as:

[0074]

[0075] Denote M as The reflectivity R of the incident light is expressed as:

[0076]

[0077] where m 11 , m 12 , m 21 , m 22 represent the four elements of the matrix, η0 and η k+1 represent the admittances of the first layer and the (k + 1)-th layer respectively;

[0078] The absorptivity T of the incident light is expressed as:

[0079]

[0080] where Re represents taking the real part of a complex number.

[0081] Under thermal equilibrium conditions, the relationship between the emissivity ε and the absorptivity A of the incident light is expressed as:

[0082] ε = A

[0083] When ignoring transmission, the reflectivity R of the incident light is expressed as:

[0084] R = 1 - A = 1 - ε

[0086] According to the method steps described above, the spectral characteristics of the thin film are calculated by programming, and the spectral curves as shown in Figure 2 , Figure 3 and Figure 4 are obtained. The spectral bands in the figure are all 380nm - 14000nm.

[0087] After calculation, the transmittance of the thin film in the visible light band is 80.49%, the transmittance in the near-infrared band is 9.31%, the reflectance in the mid-infrared band is 96.94%, and the reflectance in the far-infrared band is 97.65%. Therefore, in winter, when the equipment is used for heating indoors, the high reflection characteristics of the ordinary glass with the thin film in the mid- and far-infrared bands can almost completely reflect the thermal radiation in these two bands back into the room, reducing the radiation escape and improving the energy utilization rate; in summer, when the equipment is used for cooling indoors, the near-infrared radiation from outside is blocked due to the low transmittance of the thin film in this band and very little enters the room, reducing the energy burden required for cooling. In summary, while ensuring high visible light transmittance, the thin film achieves the design goal of energy conservation and emission reduction.

[0088] The thin film is fabricated using a vacuum electron beam evaporation equipment. The physical photos of the samples are shown in Figure 5 and Figure 6 .

[0089] Figure 5 is the glass coated with the energy-saving thin film, Figure 6 is the flexible substrate coated with the energy-saving thin film. Obviously, the energy-saving thin film exhibits good optical properties. The mid- and far-infrared properties of the two types of samples are shown in Figure 7 and Figure 8 . The rectangular coated glass forms a sharp contrast with the circular ordinary glass, and the energy-saving glass effectively isolates the radiation emitted by the heat source; the coated area of the flexible substrate is in a "convex" shape, forming a contrast with the uncoated areas at both ends, also showing excellent energy-saving effects.

[0090] Among various building energy consumptions, the energy consumption lost through glass doors and windows accounts for 50% of the total building energy consumption. In winter, the heat loss through single-glazed windows accounts for 30% - 50% of the heating load, and in summer, the cooling caused by the increase in indoor temperature due to solar radiation passing through single-glazed windows accounts for 20% - 30% of the air-conditioning load. Therefore, reducing the heat loss of glass doors and windows is an effective way to reduce the building energy consumption I5.

[0091] Low-E glass is an energy-saving glass technology that is relatively mature and widely used at present. Many studies have shown that the visible light transmittance of Low-E glass is about 60-80%, and the reflectance of near-infrared light is about 50-80%. With the increase in the number of coating layers, the visible light transmittance of Low-E glass continuously increases, and the near-infrared transmittance continuously decreases. While the energy-saving effect is gradually improved, the preparation cost is also increased. As described above, the optical properties of the energy-saving thin film in this paper are better than those of Low-E glass, with better energy-saving effect and high preparation efficiency; the film layers are closely combined, the film-forming effect is good, the properties are stable and reliable, and it can be used for a long time; it can be flexibly applied to buildings without being manufactured integrally with the glass, and is also suitable for approximate enclosed spaces such as greenhouse sheds and cars; the setting is simple, easy to install, and can be made into a foldable type later, with great potential for promotion.

[0092] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those of ordinary skill in the relevant technical fields can also make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The patent protection scope of the present invention shall be defined by the claims.

Claims

1. An energy-saving film based on solar spectrum radiation regulation, characterized in that: It includes a substrate, a first film layer, a second film layer, a third film layer, a fourth film layer and a fifth film layer which are sequentially connected from top to bottom.

2. The energy-saving film based on solar spectrum radiation regulation according to claim 1, characterized in that: The first film layer and the fifth film layer are SiO2.

3. The energy-saving film based on solar spectrum radiation regulation according to claim 2, characterized in that: The thickness of the first film layer is 70-75 nm, and the thickness of the fifth film layer is 8-10 nm.

4. The energy-saving film based on solar spectrum radiation regulation according to claim 1, characterized in that: The second film layer and the fourth film layer are ZnSe.

5. The energy-saving film based on solar spectrum radiation regulation according to claim 4, characterized in that: The thickness of the second film layer is 23-25 ​​nm, and the thickness of the fourth film layer is 21-23 nm.

6. The energy-saving film based on solar spectrum radiation regulation according to claim 1, characterized in that: The third film layer is Ag.

7. The energy-saving film based on solar spectrum radiation regulation according to claim 6, characterized in that: The thickness of the third film layer is 20-22 nm.

8. The energy-saving film based on solar spectrum radiation regulation according to claim 1, characterized in that: The substrate is K9 glass.

9. The method for calculating the spectral characteristics of energy-saving films based on solar spectrum radiation regulation according to any one of claims 1 to 8, characterized in that: The method comprises: When light with a wavelength of λ is incident on the energy-saving film at an angle θ, the tangential components of the electric field and magnetic field of the lth layer are determined to be E l and H l , the tangential components of the electric and magnetic fields in the l+1th layer are E l+1 and H l+1 , E l and H l With E l+1 and H l+1 The relationship between them is expressed as: Among them, M l The characteristic matrix of the l-th layer medium is expressed as: Among them, δ l is the effective phase thickness of the lth layer, n l and d l are the refractive index and thickness of the lth layer of medium respectively; j represents an imaginary unit; η l is the admittance of the lth layer, θ l is the refraction angle of the lth layer of medium, satisfying Snell's refraction law n l sinθ l =n l-1 sinθ l-1 =n0sinθ0 When the number of films is k, the total characteristic matrix M is expressed as: Let M be The incident light reflectivity R is expressed as: Among them, m 11 、m 12 、m 21 、m 22 Represents the four elements of the matrix, η0 and η k+1 denote the admittance of the 1st layer and the k+1th layer respectively; The incident light absorption rate T is expressed as: Here, Re represents the real part of a complex number.

10. The spectral characteristic calculation method according to claim 9, characterized in that: The method further comprises: Under thermal equilibrium conditions, the relationship between the emissivity ε and the incident light absorptivity A is expressed as: ε=A Without considering the projection, the incident light reflectivity R is expressed as: R=1-A=1-ε.

Images