A production method for improving the transmittance of solar photovoltaic glass

Abstract

The application discloses a production method for improving the transmittance of solar photovoltaic glass. According to the components of the photovoltaic glass, a batch is prepared and mixed, the mixed batch is transported to a melting furnace to be melted, clarified and homogenized to form a glass liquid, the cooled glass liquid is introduced into a calender through a gate plate to be calendered and formed, and then the photovoltaic glass required is formed after annealing and cutting. An aeration device is installed outside the melting furnace, and the aeration device introduces oxidizing gas into the glass liquid through an aeration pipe. The position where the oxidizing gas is introduced into the glass liquid is in front of a hot spot of the melting furnace, and the temperature position corresponding to the surface viscosity of the glass liquid is η=10 1.3 -10 1.8 Pa·S. According to the application, the oxidizing gas is introduced into the melting area of the glass batch through the aeration device, Fe 2+ in the glass is oxidized into Fe 3+ without changing the components of the glass, the strong absorption of Fe 2+ in the glass to the light in the 950-1100 nm band region is reduced, and the transmittance of the photovoltaic glass in the 450-1100 nm band region is improved.

Description

Technical Field

[0001] This application relates to the field of glass manufacturing technology, specifically to a production method for improving the transmittance of solar photovoltaic glass. Background Technology

[0002] As is known, photovoltaic glass is an important component of solar photovoltaic power generation modules. It is used as a cover or base plate to protect the module and allow sunlight to pass through. The transmittance of photovoltaic glass directly affects the power generation efficiency of solar photovoltaic power generation modules and is the core performance indicator of photovoltaic glass. Continuously improving the transmittance of photovoltaic glass is the goal pursued by manufacturers.

[0003] Currently, photovoltaic glass is produced using the rolling process to produce ultra-clear glass. The iron oxide content in photovoltaic glass is ≤150ppm. Reducing the iron oxide content in the glass can improve the transmittance of photovoltaic glass. However, as the iron oxide content in the glass decreases, the iron content in the glass batch also needs to be reduced, which increases the cost of the glass batch and thus increases the production cost of photovoltaic glass.

[0004] Patent CN202022193297.1 describes a method that designs a frustum-shaped regular triangular pyramid pattern on the lower surface of photovoltaic glass. This not only directly reduces the reflection of sunlight by the glass but also causes sunlight to undergo secondary, tertiary, or even more reflections and refractions between the surfaces of the frustum-shaped regular triangular pyramid, reducing light reflection loss and increasing light transmittance. However, this method requires secondary processing of the original glass sheet, and the complex pattern makes processing difficult, significantly increasing the production cost of photovoltaic glass.

[0005] Patent CN202210156448.7 describes a method for obtaining photovoltaic glass with diffused embedding and surface reconstruction of alkali metal ions by spraying an alkali metal ion solution onto the surface of photovoltaic glass and then sintering it at a temperature below the softening point of the photovoltaic glass. This invention improves the transmittance of the photovoltaic glass with the alkali metal ion-reconstructed surface by 1% to 1.5% in the 400–1100 nm light band. However, this patented method requires structural and compositional reconstruction of the glass surface, making secondary processing of the glass difficult and costly, and unsuitable for mass production.

[0006] Therefore, how to provide a production method that improves the transmittance of photovoltaic glass without increasing production costs has been a long-term technical demand for those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide a production method for improving the transmittance of solar photovoltaic glass. This method involves introducing an oxidizing gas into the melting zone of the glass batch through a gas-purifying device, thereby reducing the Fe content in the glass without altering its composition. 2+ Oxidized to Fe3+ Reduce Fe in glass 2+ It strongly absorbs light in the 950-1100nm wavelength range, thereby improving the transmittance of photovoltaic glass in the 450-1100nm wavelength range.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0009] This invention provides a method for producing solar photovoltaic glass with improved transmittance. The method involves preparing and mixing a batch of materials according to the components of photovoltaic glass. The uniformly mixed batch is then transported to a melting furnace for melting, clarification, and homogenization to form molten glass. The cooled molten glass is then fed through a gate into a rolling mill for rolling and shaping. After annealing and cutting, the desired photovoltaic glass is formed. A ventilation device is installed outside the melting furnace, and this device introduces oxidizing gas into the molten glass through a ventilation pipe. The oxidizing gas is introduced into the molten glass at a location before the hot spot of the melting furnace, and the surface viscosity of the molten glass is η = 10. 1.3 -10 1.8 At the temperature position corresponding to Pa·S, the vent pipes are arranged in two rows. The first row of vent pipes is located in front of the hot spot of the melting furnace and the surface viscosity of the molten glass is η = 10. 1.55 -10 1.8 At the temperature position corresponding to Pa·S, the second row of vent pipes is located in front of the hot spot of the melting furnace and the surface viscosity of the molten glass is η = 10. 1.3 -10 1.5 The temperature location corresponding to Pa·S.

[0010] In some embodiments, the oxidizing gas is a mixture of free oxygen atoms and oxygen gas, or a mixture of free oxygen atoms, oxygen gas, and ozone.

[0011] In some embodiments, the ventilation device is connected in sequence to the air-driving device and the oxygen ionization device. Free oxygen atoms generated in the oxygen ionization device are blown out through the air-driving device and then enter the furnace through the ventilation pipe.

[0012] In some embodiments, the vent pipe of the venting device enters from the bottom of the furnace, and the vent pipe opening of the venting device entering the furnace is approximately 200-500 mm above the bottom of the furnace pool.

[0013] In some embodiments, the oxidizing gas is introduced into the molten glass at a location before the hot spot of the furnace and the surface viscosity of the molten glass is η = 10. 1.39 -10 1.71 The corresponding temperature location.

[0014] The present invention provides a production method for improving the transmittance of solar photovoltaic glass. The oxidizing gas selected is a mixture of free oxygen atoms and oxygen with higher redox potential, or a mixture of free oxygen atoms, oxygen and ozone. This can effectively compensate for the problem of weak redox potential when only oxygen is used as the oxidizing gas, and quickly oxidize the ferrous iron in the glass melt, thereby improving the efficiency of the oxidation reaction.

[0015] This invention provides a production method for improving the transmittance of solar photovoltaic glass. The gas inlet pipe for introducing oxidizing gas is set before the hot spot in the melting furnace. When the viscosity of the molten glass is suitable, more gas than is required for the oxidation reaction can be introduced to ensure a sufficient oxidation reaction. At the same time, as the molten glass moves towards the hot spot, the temperature of the molten glass increases and the viscosity decreases. The unreacted excess oxidizing gas will be quickly discharged from the molten glass to avoid remaining in the molten glass and forming bubbles. At the same time, the discharge of oxidizing gas is also beneficial to the clarification of the molten glass.

[0016] This invention provides a production method for improving the transmittance of solar photovoltaic glass, wherein the gas is introduced into the ventilation device at a point where the viscosity of the molten glass is η = 10. 1.3 -10 1.8 Pa·s, preferably η = 10 1.39 -10 1.71 Pa·s, due to the viscosity of the molten glass being <10 1.3 At a viscosity of Pa·S, the glass melt has a very low viscosity, and oxygen-based gases such as oxygen have a high osmotic pressure, allowing them to easily and quickly escape from the glass melt, thus failing to oxidize the ferrous iron in the glass melt; when the viscosity of the glass melt is >10 Pa·S... 1.8 At a temperature of Pa·S, the viscosity of the molten glass is high and the temperature is low. Oxidizing gases diffuse slowly in the molten glass and easily form bubbles that aggregate. They cannot fully react with the ferrous iron in the molten glass. At the same time, since the oxidizing gases aggregate in the form of bubbles, as the temperature of the molten glass increases and the viscosity decreases, the oxidizing gases will be quickly discharged from the molten glass due to the increased volume of the bubbles formed by aggregation, and will not play a role in oxidizing the ferrous iron in the molten glass. Detailed Implementation

[0017] The technical solutions in some embodiments of this disclosure are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments provided in this disclosure, all other embodiments obtained by those skilled in the art are within the scope of protection of this disclosure.

[0018] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, a particular feature, structure, material, or characteristic may be included in any suitable manner in any one or more embodiments or examples.

[0019] Example

[0020] This invention provides a production method for improving the transmittance of solar photovoltaic glass. The method involves preparing and mixing batch materials according to the components of photovoltaic glass, conveying the uniformly mixed batch materials to a melting furnace for melting, clarification, and homogenization to form molten glass, and then feeding the cooled molten glass into a rolling mill through a gate for rolling and forming. Finally, the glass is annealed and cut to form the desired photovoltaic glass.

[0021] For example, this embodiment uses a commonly used photovoltaic glass composition, namely 72.6% silicon dioxide, 8.4% calcium oxide, 3.5% magnesium oxide, 1.02% aluminum oxide, 13.98% R2O (R is any one or both of Na and K), and 0.5% of other components, wherein the content of iron oxide is selected as 150 ppm.

[0022] The photovoltaic glass components described above are prepared and mixed. The uniformly mixed batch is then conveyed to the melting furnace. An auxiliary ventilation device is installed outside the melting furnace. Oxidizing gas is introduced into the molten glass through the ventilation pipe of the ventilation device. The oxidizing gas is introduced into the molten glass at a position before the hot spot of the melting furnace, and the surface viscosity of the molten glass is η = 10. 1.3 -10 1.8 The temperature corresponding to Pa·S is specified. Two rows of vent pipes are configured, with the first row located before the hot spot of the melting furnace and the surface viscosity of the molten glass being η = 10. 1.55 -10 1.8 At the temperature position corresponding to Pa·S, the second row of vent pipes is located in front of the hot spot of the melting furnace and the surface viscosity of the molten glass is η=10. 1.3 -10 1.5 The temperature location corresponding to Pa·S.

[0023] The surface viscosity of the above-mentioned molten glass is η = 10 1.3 -10 1.8 The temperature at the location corresponding to Pa·S is 1230-1352℃.

[0024] In some embodiments, preferably, the oxidizing gas is introduced into the molten glass at a location before the hot spot of the furnace and the surface viscosity of the molten glass is η = 10. 1.39 -10 1.71 The temperature location corresponding to Pa·S.

[0025] The transmittance of photovoltaic glass refers to the transmittance of light in the 380-1100nm wavelength range. Because photovoltaic glass uses components with low iron oxide content (≤150ppm), its raw materials contain few impurities. Therefore, the factors affecting transmittance are determined by the iron oxide content in the glass. Iron in glass is primarily composed of Fe. 2+ and Fe 3+ Two valence states exist, Fe 2+ It absorbs light across the entire wavelength range, particularly exhibiting two strong absorption bands in the 950-1100nm and 2050-2200nm wavelength ranges. (Fe) 3+ There are three absorption bands in the ultraviolet region at 380nm, 420nm, and 435nm. Therefore, when the iron oxide content in photovoltaic glass is constant, the Fe content in the glass... 2+ Fe content is the most significant factor affecting the transmittance of photovoltaic glass. Reducing the Fe content in photovoltaic glass... 2+ The increased Fe content can effectively reduce light absorption across the entire wavelength range, especially in the 950-1100nm range, while the increased Fe content... 3+ The content only affects the absorption of light in the three ultraviolet absorption regions of 380nm, 420nm and 435nm, thereby improving the transmittance of photovoltaic glass in the 450-1100nm wavelength range.

[0026] Fe in glass 2+ To Fe 3+ The transformation is essentially Fe 2+ The process of losing electrons and being oxidized is called a redox reaction. Taking the reaction of ferrous ions with oxygen as an example, the redox reaction formula is as follows:

[0027] 4FeO + O₂ → 2Fe₂O₃ The redox potential is usually used to assess the tendency of a reducing agent to lose electrons (or the tendency of an oxidizing agent to gain electrons). The redox potential of ferrous iron (Fe²⁺) is -0.44V, and that of ferric iron (Fe³⁺) is 0.77V. To make Fe²⁺... 2+ To Fe 3+ The reaction requires ferrous iron to react with an element with a high redox potential, oxidizing the ferrous iron to ferric iron. Oxygen has a redox potential of 1.23V, an oxygen atom has a redox potential of 2.42V, and ozone has a redox potential of 2.07V, providing a significant potential difference compared to ferrous iron, which facilitates the smooth progress of the redox reaction.

[0028] This invention provides a production method for improving the transmittance of solar photovoltaic glass, which involves introducing an oxidizing gas into the molten glass in a melting furnace through a ventilation device, thereby increasing the Fe content in the molten glass. 2+ Oxidized to Fe 3+ It can realize Fe in photovoltaic glass 2+ To Fe 3+ Transformation, reducing Fe in glass 2+ The element absorbs light across the entire wavelength range, especially exhibiting strong absorption in the 950-1100nm region, increasing the absorption of Fe. 3+ The content only affects the absorption of light in the three ultraviolet absorption regions of 380nm, 420nm, and 435nm, that is, it reduces the Fe content in photovoltaic glass. 2+ Strong absorption in the near-infrared region improves the transmittance of photovoltaic glass in the 450-1100nm wavelength range.

[0029] The present invention provides a production method for improving the transmittance of solar photovoltaic glass. It does not require secondary processing of the photovoltaic glass. The requirement to improve the transmittance of photovoltaic glass can be achieved by carrying out an oxidation-reduction reaction only during the melting stage of the glass. It is easy to operate and has excellent results.

[0030] In some embodiments, the oxidizing gas is a mixture of free oxygen atoms and oxygen gas, or a mixture of free oxygen atoms, oxygen gas, and ozone.

[0031] In some embodiments, the ventilation device is connected in sequence to the air-driving device and the oxygen ionization device. The free oxygen atoms generated in the oxygen ionization device are blown out by the air-driving device and then enter the furnace through the ventilation pipe of the ventilation device.

[0032] Free oxygen atoms, along with oxygen or oxygen and ozone, enter the furnace through the ventilation pipe of the ventilation device, thus making the oxidizing gas introduced into the furnace a mixture of free oxygen atoms and oxygen, or a mixture of free oxygen atoms, oxygen, and ozone.

[0033] In some embodiments, the vent pipe of the venting device enters from the bottom of the furnace, and the vent pipe opening of the venting device entering the furnace is about 200-500 mm above the bottom of the furnace pool.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A method for producing solar photovoltaic glass with improved transmittance, comprising: preparing and mixing batch materials according to the components of photovoltaic glass; conveying the uniformly mixed batch materials to a melting furnace for melting, clarification, and homogenization to form molten glass; feeding the cooled molten glass through a gate into a rolling mill for rolling and shaping; and then annealing and cutting to form the desired photovoltaic glass, characterized in that: A ventilation device is installed outside the melting furnace, which introduces oxidizing gas into the molten glass through a ventilation pipe; the oxidizing gas is introduced into the molten glass at a location before the hot spot of the melting furnace, and the surface viscosity of the molten glass is η=10. 1.3 -10 1.8 The temperature position corresponding to Pa·S; the vent pipe is provided in two rows, the first row of vent pipes is located in front of the hot spot of the melting furnace and the surface viscosity of the molten glass is η=10. 1.55 -10 1.8 At the temperature position corresponding to Pa·S, the second row of vent pipes is located in front of the hot spot of the melting furnace and the surface viscosity of the molten glass is η=10. 1.3 -10 1.5 The temperature location corresponding to Pa·S; The oxidizing gas is a mixture of free oxygen atoms and oxygen gas, or a mixture of free oxygen atoms, oxygen gas, and ozone.

2. The production method for improving the transmittance of solar photovoltaic glass as described in claim 1, characterized in that, The ventilation device is connected in sequence to the air-driving device and the oxygen ionization device. The free oxygen atoms generated in the oxygen ionization device are blown out through the air-driving device and then enter the furnace through the ventilation pipe of the ventilation device.

3. The production method for improving the transmittance of solar photovoltaic glass as described in claim 1, characterized in that, The ventilation pipe of the ventilation device enters from the bottom of the furnace, and the ventilation pipe opening of the ventilation device entering the furnace is 200-500mm above the bottom of the furnace pool.

4. The production method for improving the transmittance of solar photovoltaic glass as described in claim 1, characterized in that, The oxidizing gas is introduced into the molten glass at a location before the hot spot of the furnace, and the surface viscosity of the molten glass is η=10. 1.39 -10 1.71 The corresponding temperature location.