A method and device for preparing ultra-thin rolled glass for solar cells

Abstract

The present invention relates to a preparation method and a preparation device for ultra-thin rolled glass for solar cells. Compared with the existing rolled glass preparation technology, the present invention targets the particularity of ultra-thin rolled glass for solar cells, conducts technical innovations in multiple processes, and forms a brand-new ultra-thin rolled glass preparation technology. Specifically, it includes: in the glass component selection and batching process, optimizing the design of glass components to improve the impact resistance of ultra-thin rolled glass; in the melting and clarification process, improving the clarifier formula and setting the melting furnace combustion atmosphere to an oxidizing atmosphere to achieve efficient melting and clarification of the glass liquid; in the forming process, adopting a multi-stage rolling forming process to achieve the forming of ultra-thin glass ribbons with small thickness differences; in the annealing process, adopting an annealing process that finely controls the temperature of each annealing area and accurately controls the cooling rate of the glass ribbon to achieve precise annealing of the ultra-thin rolled glass ribbon. The ultra-thin rolled glass produced by the present invention has the advantages of small thickness difference, high impact resistance, and high transmittance.

Description

Technical Field

[0001] The present invention relates to the field of glass manufacturing, and in particular to a method and a device for preparing ultra-thin rolled glass for solar cells. Background Art

[0002] Solar power generation, with its advantages of abundant energy resources, mature technology, and low cost, has become a significant global new energy industry. Solar panels are the core components of solar power systems. my country is a global manufacturing hub for these panels. These panels consist of multiple solar cells. Glass is a crucial component of solar cells, protecting them from moisture and air, thus preventing corrosion and oxidation.

[0003] Glass for solar cells is usually made from rolled glass that has undergone deep processing. The existing method for producing rolled glass is to roll-form the molten glass in a single process. The single-roll forming process enables the industrial production of rolled glass with a thickness of 1.6 mm and above. If the thickness of the rolled glass can be further reduced based on the 1.6 mm thickness, it will not only significantly reduce the weight of the solar cell module and increase the application scenarios of the solar cell module, but also improve the light transmittance of the rolled glass, effectively increasing the power generation efficiency of the solar cell. It can also reduce the amount of raw materials and fuel required for the production of rolled glass, thereby reducing production costs and effectively saving resources. However, when the existing production process is used to produce rolled glass with a thickness of less than 1.6 mm, the thickness difference of the glass will be large, and this will cause the following problems: First, when it is necessary to coat the glass surface with a film, the commonly used roller coating process cannot be used. The reason is that when the roller coating process is used to coat glass with a large thickness difference, the film thickness uniformity is poor, which affects the light transmittance of the glass, and the use of other coating processes will significantly increase the production cost; Second, ultra-thin rolled glass with a large thickness difference has poor bending resistance and impact resistance. When the glass plate and other components are laminated together during the preparation of solar cells, the glass plate is prone to bursting, resulting in the scrapping of the solar cell.

[0004] Therefore, how to achieve the industrial production of rolled glass with a thickness of less than 1.6 mm and a small thickness difference has become an urgent problem that needs to be solved in the industry. Summary of the Invention

[0005] To address these technical issues, the inventors' team, building on existing processes for producing rolled glass for solar cells, innovated multiple steps and developed a novel production method. This method produces ultra-thin rolled glass with minimal thickness differences, excellent impact resistance, and high light transmittance.

[0006] The specific technical solutions of the present invention are:

[0007] A method for preparing ultra-thin rolled glass for solar cells, comprising:

[0008] Glass component selection and batching process: weigh the raw materials according to the composition design suitable for ultra-thin rolled glass, mix the raw materials to form a batch, and transport the batch to the melting furnace;

[0009] Melting and clarification process: A melting furnace with a bubbling clarification device is used to melt and clarify the batch material, and the melted and clarified glass liquid flows into the forming device;

[0010] Forming process: The glass liquid is formed into an ultra-thin glass ribbon through a multi-stage continuous roller forming device, and the glass ribbon is sent to the annealing furnace;

[0011] Annealing process: annealing the glass ribbon through multiple annealing zones with independently controlled temperatures;

[0012] Cutting process: The annealed glass ribbon is inspected and cut, then packaged and stored or directly enters the further processing process.

[0013] Hereinafter, each of the above steps will be described one by one.

[0014] Glass Component Selection and Batching Process: Preferably, the present invention constructs a novel glass composition by appropriately reducing the Na2O and CaO contents of existing rolled glass for solar cells, increasing the SiO2 and Al2O3 contents, and adding oxides such as K2O, B2O3, and ZrO2. This composition reduces the glass's thermal expansion coefficient, improving its mechanical and impact resistance. It also minimizes the glass's viscosity-temperature gradient, facilitating the implementation of multi-stage rolling processes. It also reduces Na2O precipitation in high-temperature, high-humidity environments, inhibiting and reducing the potential-induced degradation (PID) effect in solar cells. Furthermore, by controlling the ratio of the average particle size of the soda ash used to introduce the Na2O to the average particle size of the silica sand used to introduce the SiO2, the present invention achieves superior batch uniformity after mixing, achieving a batch mean square deviation of ≤0.28, thereby improving melting quality.

[0015] Melting and clarification process: As a preferred embodiment, the melting and clarification process of the present invention includes the following improvements: adding a clarifier to the batch material and setting a bubbling clarification device in the melting furnace to reduce the number of bubbles in the glass, improve the clarification quality of the glass liquid, and improve the quality of the glass; adjusting the combustion atmosphere in the melting furnace to an oxidizing atmosphere to increase the Fe content in the glass. 2+ Converted to Fe 3+ ratio, improving the light transmittance of the glass in the wavelength range of 380-1100nm.

[0016] Molding process: Preferably, the present invention adopts a new multi-stage continuous calendering molding process to shape the molten glass into an ultra-thin glass ribbon. First, the molten glass flowing out of the melting furnace enters the runner. Next, the molten glass after passing through the runner flows into the first calendering unit through the lip brick. The viscosity of the molten glass when entering the first calendering unit is controlled by a heating and cooling device laid on the runner. The molten glass is rolled by the first calendering unit to form a glass ribbon with a first thickness, and the first thickness is preferably 2.5mm to 5.0mm. Thereafter, the glass ribbon passing through the first calendering unit enters the second calendering unit via rollers. The viscosity of the glass ribbon when entering the second calendering unit is controlled by a heating and cooling device arranged between the first and second calendering units. The glass ribbon is rolled by the second calendering unit to form a glass ribbon with a second thickness, and the second thickness is preferably 0.5mm to 2.0mm, and more preferably less than 1.6mm.

[0017] Preferably, a throttling device is provided at the end of the flow channel, and further preferably, the throttling device is a throttling roller provided above the end of the flow channel, and the flow rate of the glass liquid is controlled by the distance between the lower busbar of the throttling roller and the bottom surface of the horizontal flow channel and the rotation speed of the throttling roller, thereby achieving flow limiting of the glass liquid.

[0018] Preferably, the throttling roller and the upper and lower rollers of the first calendering unit are all smooth-surfaced rollers. The upper roller of the second calendering unit has a preset roughness, and the lower roller has a preset pattern. Compared to single-stage calendering, multi-stage continuous calendering can meet the production needs of ultra-thin rolled glass with small thickness differences.

[0019] Annealing process: Preferably, the annealing process of the present invention adopts a method of finely controlling the annealing temperature of each area in the annealing furnace and the cooling rate of the glass ribbon, which significantly reduces the residual stress in the glass, effectively avoids deformation, cracking and other problems of the glass ribbon during the annealing process, and realizes stable and efficient production of high-quality ultra-thin rolled glass.

[0020] Cutting: After annealing, the glass ribbon undergoes online quality inspection, cutting, edge breaking, and slicing to obtain finished glass products of the required size. The glass products are packaged and stored in warehouses or directly processed.

[0021] The present invention also relates to a production apparatus used in the above-mentioned production method. The production apparatus comprises a batching device, a melting furnace, a forming device, an annealing lehr, and a cutting device. The forming device comprises a multi-stage continuous calendering roller assembly and related equipment. The above-mentioned apparatus can be used to produce high-quality ultra-thin rolled glass.

[0022] The present invention has formed a new forming and preparation process by making technical innovations in multiple steps of the method for preparing rolled glass for solar cells, which can achieve the following beneficial effects: by optimizing the design of glass components, the impact resistance of ultra-thin rolled glass is improved, and the PID effect of solar cells is reduced; by optimizing the design of the clarifier and adjusting the combustion atmosphere of the melting furnace, the glass liquid is efficiently clarified, and the Fe in the glass is promoted. 2+ Fe 3+ The transformation improves the light transmittance of the glass; the multi-stage continuous rolling process is used to form ultra-thin rolled glass with a small thickness difference. The innovative combination of these multiple processes ultimately realizes the industrial production of high-quality ultra-thin rolled glass with a thickness of less than 1.6mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attachment Figure 1 Schematic diagram of the overall process of preparing ultra-thin rolled glass for solar cells.

[0024] Attachment Figure 2 Schematic diagram of the melting furnace in the melting and clarification process.

[0025] Attachment Figure 3 Schematic diagram of the melting furnace bubbling clarification device in the melting and clarification process.

[0026] Attachment Figure 4 Schematic diagram of the molding device in the molding process.

[0027] Attachment Figure 5 Schematic diagram of the annealing kiln in the annealing process.

[0028] Reference numerals:

[0029] Melting furnace 100; feeding machine 101; neck 102; transverse channel 103; branch channel 104; bubbling clarification device 105; throttling roller group 10; throttling roller frame 11; throttling roller 12; first calendering roller group 20; first frame 21; first calendering upper roller 22; first calendering lower roller 23; second calendering roller group 30; second frame 31; second calendering upper roller 32; second calendering lower roller 33; lip brick 40; roller 51; traction roller 52; first heating device 61; second heating device 62; first cooling device 63; second cooling device 64; glass liquid 71; glass ribbon 72; flow channel 80; first direction X; second direction Y, soaking zone 301; important cooling zone 302; slow cooling zone 303; rapid cooling zone 304; rapid cooling zone 305. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments derived by ordinary technicians in this field based on the above embodiments are within the scope of protection of the present invention.

[0031] Specifically, the present invention provides a method for preparing ultra-thin rolled glass for solar cells, such as Figure 1 As shown, the glass preparation method includes the following steps:

[0032] Glass component selection and batching process: Weigh each component according to the composition design suitable for ultra-thin rolled glass, mix the components to form a batch material, and transport the batch material to the melting furnace;

[0033] Melting and clarification process: A melting furnace with a bubbling clarification device is used to melt and clarify the batch material, and the melted and clarified glass liquid flows into the forming device;

[0034] Forming process: The glass liquid is formed into an ultra-thin glass ribbon through a two-stage continuous roller forming device, and the glass ribbon is sent to the annealing furnace;

[0035] Annealing process: annealing the glass ribbon through multiple annealing zones with independently controlled temperatures;

[0036] Cutting process: The annealed glass ribbon is inspected and cut, then packaged and stored or directly enters the further processing process.

[0037] Below, each step is explained one by one.

[0038] Glass component selection and batching process

[0039] Solar cell glass must protect the power generation components in a variety of environments, such as high temperature, high humidity, and sand and gravel impact. To achieve this, the glass must have high impact resistance and effectively reduce the PID effect of solar cells.

[0040] Preferably, the glass components used in the present invention include, by weight percentage: 72.4% to 74.5% SiO2, 0.9% to 3.8% Al2O3, 0.009% to 0.012% Fe2O3, 2.2% to 4.0% CaO, 3.8% to 5.2% MgO, 10% to 11.5% Na2O, 0.5% to 1.2% B2O3, 0.5% to 2.5% K2O, and 0.05% to 1.0% ZrO2, wherein B2O3 + ZrO2 is 0.8% to 2.6%, and K2O + Na2O is 11 to 13%.

[0041] Compared to conventional rolled glass for solar cells, this glass composition reduces the Na2O and CaO contents, increases the SiO2 and Al2O3 contents, and adds oxides such as K2O, B2O3, and ZrO2. Adjusting these components and their contents not only facilitates multi-stage rolling processes for molding, but also improves the glass's thermal stability, chemical stability, and mechanical strength, enhancing impact resistance, and strengthening protection for solar cell modules, extending their lifespan. It also effectively reduces the PID effect in solar cells.

[0042] In addition, the uniformity of the glass batch will directly affect its melting effect. In some embodiments of the present invention, the raw material for introducing SiO2 into the batch is silica sand, and the raw material for introducing Na2O is soda ash. By controlling the ratio of the average particle size of soda ash to the average particle size of silica sand, the uniformity of the batch mixing can be improved. Preferably, the average particle size of soda ash / the average particle size of silica sand is 0.7 to 0.8, more preferably 0.72 to 0.75. By controlling the ratio of the average particle size of soda ash to the average particle size of silica sand, the mean square deviation of the mixed batch can be achieved to be ≤0.28.

[0043] The raw materials for the batch are weighed according to the glass composition design. The weighed raw materials are conveyed to the mixer via a collection belt for mixing. The evenly mixed batch is then conveyed to the kiln head silo via a belt. It is preferred to add a certain proportion of cullet to the batch.

[0044] Melting and clarification process

[0045] As a preference, Figure 2 and Figure 3 As shown, after the batch material is fed into the kiln head hopper, the batch material is pushed into the melting furnace 100 through the feeder 101 below the kiln head hopper. The batch material is melted, clarified, and homogenized in the melting furnace 100 to form a uniform glass liquid. The glass liquid flows into the cross channel 103 after passing through the neck 102, and is then transported to the forming device through each branch channel 104 for forming. In order to improve the clarification effect of the glass liquid, it is preferred to add a clarifier to the batch material. In addition, the glass liquid can be subjected to enhanced bubbling clarification by the bubbling clarification device 105. The combustion atmosphere of the melting furnace is preferably an oxidizing atmosphere to reduce the Fe in the glass. 2+ content, thereby increasing the light transmittance of the glass.

[0046] In some embodiments of the present invention, sodium pyroantimonate is selected as the glass clarifier, and the amount of sodium pyroantimonate used accounts for 0.1-0.35% by weight of the batch material, preferably 0.22-0.3%.

[0047] In some embodiments of the present invention, a composite clarifier is selected as the glass clarifier, and the components of the composite clarifier include antimony trioxide, sodium sulfate, sodium nitrate, etc., wherein the amount of antimony trioxide accounts for 0.1-0.16% of the weight of the batch material, the amount of sodium nitrate accounts for 1.0-2.0% of the weight of the batch material, and the amount of sodium sulfate accounts for 0.8-1.8% of the weight of the batch material. Preferably, the amount of antimony trioxide accounts for 0.12-0.14% of the weight of the batch material, the amount of sodium nitrate accounts for 1.1-1.5% of the weight of the batch material, and the amount of sodium sulfate accounts for 1.0-1.3% of the weight of the batch material.

[0048] In some embodiments of the present invention, at least one row of bubbling clarification devices 105 is provided near the hot spot of the melting furnace. The gas introduced into the molten glass through the bubbling clarification devices 105 is compressed air, oxygen, etc., preferably oxygen.

[0049] In some embodiments of the present invention, the combustion atmosphere of the melting furnace is preferably an oxidizing atmosphere, and the excess air coefficient in the furnace is ≥1.2.

[0050] Molding process

[0051] As a preference, Figure 4 As shown, the forming device includes a throttle roller set 10, a first calendering roller set 20, a second calendering roller set 30, a lip brick 40, and an idler roller 51. The throttle roller set 10, the first calendering roller set 20, and the second calendering roller set 30 are arranged in sequence along a first direction X. The throttle roller set 10 includes a throttle roller frame 11, throttle rollers 12 spaced apart from the throttle roller frame 11 along a second direction Y, and a drive device (not shown) for driving the throttle rollers 12 to rotate. The first calendering roller set 20 includes a first frame 21, a first calendering upper roller 22 and a first calendering lower roller 23 spaced apart from the first frame 21 along the second direction Y, and a first drive device (not shown) for driving the first calendering upper roller 22 and the first calendering lower roller 23 in opposite directions. The second rolling roller assembly 30 includes a second frame 31, a second upper rolling roller 32 and a second lower rolling roller 33 spaced apart from each other along the second direction Y, and a second drive device (not shown) that drives the second upper rolling roller 32 and the second lower rolling roller 33 in opposite directions. An idler roller 51 is disposed between the first rolling roller assembly 20 and the second rolling roller assembly 30 and is used to convey the glass ribbon 72.

[0052] In some embodiments of the present invention, the distance h1 between the lower busbar of the throttle roller 12 and the bottom surface of the flow channel, the speed of the throttle roller 12 , the distance h2 between the first calendering upper roller 22 and the first calendering lower roller 23, the rotation speed of the first calendering upper roller 22 and the first calendering lower roller 23 The following conditions are met: , preferably , more preferably The thickness of the glass ribbon after being rolled by the first rolling roller group 20 is 2.5 mm to 5 mm, preferably 2.7 mm to 4.5 mm, and more preferably 3.0 mm to 3.8 mm.

[0053] The distance h2 between the first calendering upper roller 22 and the first calendering lower roller 23, the rotation speed of the first calendering upper roller 22 and the first calendering lower roller 23 , the distance h3 between the second calendering upper roller 32 and the second calendering lower roller 33, the rotation speed of the second calendering upper roller 32 and the second calendering lower roller 33 The following conditions are met: , preferably , more preferably The thickness of the glass ribbon after being rolled by the second rolling roller group is 0.5 mm to 2 mm, preferably 0.8 mm to 1.8 mm, more preferably 1.0 mm to 1.6 mm, and further preferably 1.3 mm to 1.5 mm.

[0054] like Figure 4 As shown, a first heating device 61 and a first cooling device 63 are provided between the throttling roller set 10 and the first calendering roller set 20, and a second heating device 62 and a second cooling device 64 are provided between the first calendering roller set 20 and the second calendering roller set 30. The first heating device 61 and the first cooling device 63 are provided above and / or to the side of the flow channel 80. The second heating device 62 and the second cooling device 64 are provided above and / or to the side of and / or below the idler 51.

[0055] After the molten glass 71 passes through the throttling roller set 10, if the temperature of the molten glass 71 in the flow channel 80 drops too quickly, a roller sticking phenomenon will occur during the first rolling process, that is, the molten glass 71 adheres to the surfaces of the first rolling upper roller 22 and the first rolling lower roller 23. This will affect the distance between the first rolling upper roller 22 and the first rolling lower roller 23, making it impossible for the glass ribbon 72 to be formed into the expected thickness. In the embodiment of the present invention, according to the actual temperature of the molten glass 71, the first heating device 61 can be used to heat the molten glass 71 when the temperature is low, and the first cooling device 63 can be used to cool the molten glass 71 when the temperature is high. When the temperature of the molten glass 71 is appropriate, no heating or cooling intervention is performed. The above process can ensure that the molten glass 71 has fluidity and meets the viscosity required for rolling by the first rolling unit 20. After the molten glass 71 is rolled by the first rolling roller set 20, a solid glass ribbon 72 is formed. If the temperature of the glass ribbon 72 drops too quickly, it can easily shrink and deform, preventing it from being smoothly conveyed to the second calendering roller set 30 for further forming. If the temperature of the glass ribbon 72 is too high, it can soften and deform, preventing it from being smoothly conveyed to the second calendering roller set 30 for further forming. In this embodiment of the present invention, the glass ribbon 72 can be heated, cooled, or left alone by the second heating device 62 and the second cooling device 64, depending on actual needs. This maintains the glass ribbon 72 at an appropriate temperature, ensuring smooth conveyance to the second calendering roller set 30 and achieving the viscosity required for forming. Furthermore, maintaining the glass ribbon 72 within an appropriate viscosity range upon entering the second calendering roller set 30 ensures that the surface roughness of the glass ribbon 72 after being formed by the second calendering roller set 30 matches a predetermined roughness. This prevents the glass ribbon 72 from overheating, causing self-polishing of the glass surface and affecting the light transmittance of the glass.

[0056] The viscosity of the glass liquid when entering the first calendering roller group is preferably 10 1.89 Pa·S~10 4.14 Pa·S, more preferably 10 2.59 Pa·S~10 3.65 Pa·S, more preferably 10 2.78 Pa·S~10 3.22 Pa.S.

[0057] The viscosity of the glass ribbon entering the second rolling roller group is preferably 10 3.65 Pa·S~10 6.81 Pa·S, more preferably 10 4.03 Pa·S~10 6.23 Pa·S, more preferably 10 4.71 Pa·S~10 5.71 Pa.S.

[0058] In some embodiments of the present invention, the throttle roller 12, the first upper rolling roller 22, and the second lower rolling roller 23 are all smooth-surfaced rollers, so that the surface of the glass ribbon 72 after the primary rolling process is smooth. This configuration can reduce the rolling resistance of the throttle roller and the primary rolling process.

[0059] The surface of the second calendering upper roller 32 has a preset roughness, while the surface of the second calendering lower roller 33 has a preset pattern. This results in the glass ribbon 72 having a velvet upper surface and an embossed lower surface after the second calendering. This arrangement improves the light transmittance of the glass ribbon 72. The surface roughness of the second calendering upper roller is preferably 5 to 7 μm.

[0060] When the molten glass 71 enters the throttle roller 12 of the throttle roller assembly 10, the drive device drives the throttle roller 12 to rotate counterclockwise relative to the flow direction of the molten glass 71, restricting the flow of the molten glass 71. The restricted molten glass 71 flows through the lip brick 40 and into the space between the first upper rolling roller 22 and the first lower rolling roller 23 of the first rolling roller assembly 20. The first drive device drives the first upper rolling roller 22 and the first lower rolling roller 23 to rotate in opposite directions, further rolling the molten glass 71 and forming it into a glass ribbon 72. After being rolled and formed by the first rolling roller assembly, the glass ribbon 72 is conveyed via the support roller 51 to the space between the second upper rolling roller 32 and the second lower rolling roller 33 of the second rolling roller assembly 30. The second drive device drives the second upper rolling roller 32 and the second lower rolling roller 33 to rotate in opposite directions, further rolling the glass ribbon 72 and reducing its thickness. This multi-stage rolling process produces a glass ribbon with a small thickness difference. The traction rollers 52 deliver the multi-stage roll-formed glass ribbon 72 into an annealing furnace for annealing.

[0061] Annealing process

[0062] As a preferred method, in order to achieve more precise annealing and reduce the residual stress in the glass ribbon to a lower level, the following annealing process is adopted: Figure 5 As shown, the annealing lehr includes five zones, namely, soaking zone 301, critical cooling zone 302, slow cooling zone 303, rapid cooling zone 304, and rapid cooling zone 305. Annealing of the glass ribbon 72 is achieved by precisely controlling the cooling rate of the glass ribbon.

[0063] The soaking zone 301 is used to keep the temperature of the glass ribbon 72 uniform after entering the annealing furnace and control the temperature to the upper limit of the annealing temperature of the glass. The temperature range of the soaking zone is about 550-650°C.

[0064] The important cooling zone 302 is used to uniformly reduce the temperature of the glass ribbon 72 to the lower limit of the annealing temperature of the glass. The temperature range of the important cooling zone is about 450-550°C, and the cooling rate is controlled at 3.5-6°C / m, preferably 4-5°C / m, and more preferably 4.2-4.6°C / m.

[0065] The slow cooling zone 303 is a key area for generating temporary stress. This area slowly cools the glass ribbon to prevent excessive temporary stress and cracking. The slow cooling zone has a temperature range of approximately 320°C to 450°C, and a cooling rate of 4°C to 7.5°C / m, preferably 5°C to 7°C / m, and more preferably 5.8°C to 6.5°C / m.

[0066] The rapid cooling zone 304 cools the glass ribbon naturally to a temperature range of about 180-320° C., and the cooling rate is controlled at 6-10° C. / m, preferably 7-9° C. / m, and more preferably 7.8-8.6° C. / m.

[0067] The rapid cooling zone 305 uses forced cooling by blowing air to rapidly cool the glass ribbon. The temperature range of the rapid cooling zone is about 70-180°C, and the cooling rate is controlled at 9-14°C / m, preferably 10-12°C / m, and more preferably 10.5-11.2°C / m.

[0068] Cutting process

[0069] After annealing, the glass ribbon can be processed through online quality inspection, cutting, edge breaking and slicing according to the glass size requirements of the manufacturer to obtain the finished glass product. After that, it can be packaged and stored or directly enter the further processing process.

[0070] It should be noted that the implementation of the present invention does not require the simultaneous adoption of all the preferred embodiments described above or the achievement of all the advantages described above.

[0071] Example

[0072] Examples 1-15 illustrate technical solutions for producing rolled glass of varying thicknesses using specific embodiments of the present invention. Different technical parameters were selected for the molding process in each example. Comparative Examples 1, 2, and 3 illustrate technical solutions for producing rolled glass of 1.6 mm, 1.5 mm, and 1.3 mm thicknesses, respectively, using an existing single-stage rolling molding process. The molding process technical parameters and specific molding thicknesses for Examples 1-15 and Comparative Examples 1-3 are shown in Table 1. The molded glass was annealed and cut, and then tested for thickness and thickness difference.

[0073] Glass thickness and thickness difference tests are carried out in accordance with the requirements of the national standard GB / T 30984-2015 "Solar Glass Part 1: Ultra-clear Patterned Glass".

[0074] Table 1 Properties of rolled glass in the same embodiment and comparative example

[0075]

[0076] It can be seen from Table 1 that the thickness difference of the 1.6 mm rolled glass produced by the multi-stage continuous rolling forming process of the present invention is significantly better than the thickness difference of the 1.6 mm rolled glass produced by the technical solution of Comparative Example 1.

[0077] In addition, it can be seen from Table 1 that the technical solution of the present invention can produce ultra-thin rolled glass with a small thickness difference of less than 1.6 mm. , When the multi-stage rolling forming process parameter requirements of " are met, the thickness difference of the 1.5mm thick rolled glass produced by the technical solution of the present invention is between 0.14mm and 0.19mm, which is better than the thickness difference of the 1.5mm thick rolled glass produced by the technical solution of Comparative Example 2; the thickness difference of the 1.3mm thick rolled glass produced by the technical solution of the present invention is between 0.18mm and 0.24mm, which is better than the thickness difference of the 1.3mm thick rolled glass produced by the technical solution of Comparative Example 3. When the above process parameter requirements are deviated from, the thickness difference will increase. Therefore, the application of the technical solution of the present invention can realize the production of high-quality rolled glass with a thickness of less than 1.6mm.

[0078] The above specific embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A method for preparing ultra-thin rolled glass for solar cells, characterized in that: The preparation method comprises the following steps: Glass component selection and batching process: weigh the raw materials according to the composition design suitable for ultra-thin rolled glass, mix the raw materials to form a batch material, and transport the batch material to the melting furnace; Melting and clarification process: A melting furnace with a bubbling clarification device is used to melt and clarify the batch material, and the melted and clarified glass liquid flows into the forming device; Molding process: The glass liquid is formed into an ultra-thin rolled glass ribbon through a multi-stage continuous roll-forming device, wherein the first stage of rolling forms the glass liquid into a glass ribbon with a first thickness, and the second stage of rolling forms the glass ribbon into a glass ribbon with a second thickness, which is smaller than the first thickness. The ultra-thin rolled glass ribbon after multi-stage rolling is fed into an annealing furnace; Annealing process: annealing the ultra-thin rolled glass ribbon through multiple annealing zones with independently controlled temperatures; The forming device includes a first calendering roller group and a second calendering roller group. The first calendering roller group includes a first calendering upper roller and a first calendering lower roller. The second calendering roller group includes a second calendering upper roller and a second calendering lower roller. The distance h2 between the first calendering upper roller and the first calendering lower roller, the speed of the first calendering upper roller and the first calendering lower roller , the distance h3 between the second calendering upper roller and the second calendering lower roller, the speed of the second calendering upper roller and the second calendering lower roller satisfy: .

2. The method for preparing ultra-thin rolled glass for solar cells according to claim 1, wherein: The glass batch materials include, by weight percentage, 72.4% to 74.5% SiO2, 0.9% to 3.8% Al2O3, 0.009% to 0.012% Fe2O3, 2.2% to 4.0% CaO, 3.8% to 5.2% MgO, 10% to 11.5% Na2O, 0.5% to 1.2% B2O3, 0.5% to 2.5% K2O, and 0.05% to 1.0% ZrO2, of which B2O3 + ZrO2 is 0.8% to 2.6%, and K2O + Na2O is 11 to 13%.

3. The method for preparing ultra-thin rolled glass for solar cells according to claim 1, wherein: The glass batch material includes a composite clarifier, and the composite clarifier components include: antimony trioxide accounting for 0.1-0.16% of the batch material weight, sodium nitrate accounting for 1.0-2.0% of the batch material weight, and sodium sulfate accounting for 0.8-1.8% of the batch material weight.

4. The method for preparing ultra-thin rolled glass for solar cells according to claim 3, wherein: The amount of antimony trioxide in the composite clarifier accounts for 0.12-0.14% of the weight of the batch material, the amount of sodium nitrate accounts for 1.1-1.5% of the weight of the batch material, and the amount of sodium sulfate accounts for 1.0-1.3% of the weight of the batch material.

5. The method for preparing ultra-thin rolled glass for solar cells according to claim 1, wherein: The gas introduced into the glass liquid by the bubbling clarification device is oxygen.

6. The method for preparing ultra-thin rolled glass for solar cells according to claim 1, wherein: The distance h2 between the first calendering upper roller and the first calendering lower roller, the speed of the first calendering upper roller and the first calendering lower roller , the distance h3 between the second calendering upper roller and the second calendering lower roller, the speed of the second calendering upper roller and the second calendering lower roller satisfy: .

7. The method for preparing ultra-thin rolled glass for solar cells according to claim 1, wherein: The distance h2 between the first calendering upper roller and the first calendering lower roller, the speed of the first calendering upper roller and the first calendering lower roller , the distance h3 between the second calendering upper roller and the second calendering lower roller, the speed of the second calendering upper roller and the second calendering lower roller satisfy: .

8. The method for preparing ultra-thin rolled glass for solar cells according to any one of claims 6 to 7, characterized in that: The multi-stage continuous roller forming device comprises a throttling device, which is provided with a throttling roller, and the throttling roller realizes flow limiting of the glass liquid.

9. The method for preparing ultra-thin rolled glass for solar cells according to claim 8, wherein: The multi-stage continuous roll forming device includes a flow channel connected to the melting furnace. The throttle roller is arranged above the end of the flow channel. The flow rate of the glass liquid is controlled by the distance between the lower busbar of the throttle roller and the bottom surface of the flow channel and the rotation speed of the throttle roller, thereby achieving flow limiting of the glass liquid.

10. The method for preparing ultra-thin rolled glass for solar cells according to claim 9, wherein: The distance h1 between the lower busbar of the throttle roller and the bottom surface of the flow channel, the speed of the throttle roller , the distance h2 between the first calendering upper roller and the first calendering lower roller, the speed of the first calendering upper roller and the first calendering lower roller satisfy: .

11. The method for preparing ultra-thin rolled glass for solar cells according to claim 10, wherein: The distance h1 between the lower busbar of the throttle roller and the bottom surface of the flow channel, the speed of the throttle roller , the distance h2 between the first calendering upper roller and the first calendering lower roller, the speed of the first calendering upper roller and the first calendering lower roller satisfy: .

12. The method for preparing ultra-thin rolled glass for solar cells according to claim 11, wherein: The distance h1 between the lower busbar of the throttle roller and the bottom surface of the flow channel, the speed of the throttle roller , the distance h2 between the first calendering upper roller and the first calendering lower roller, the speed of the first calendering upper roller and the first calendering lower roller satisfy: .

13. The method for preparing ultra-thin rolled glass for solar cells according to claim 1, wherein: An idler roller is provided between the first calendering roller group and the second calendering roller group.

14. The method for preparing ultra-thin rolled glass for solar cells according to claim 8, wherein: A first heating device and a first cooling device are provided between the throttling roller group and the first calendering roller group, and a second heating device and a second cooling device are provided between the first calendering roller group and the second calendering roller group.

15. The method for preparing ultra-thin rolled glass for solar cells according to claim 14, wherein: The first heating device and the first cooling device are arranged above and / or on the side of the flow channel for conveying molten glass between the throttling roller group and the first rolling roller group.

16. The method for preparing ultra-thin rolled glass for solar cells according to claim 14, wherein: The second heating device and the second cooling device are arranged above and / or on the side and / or below the support rollers between the first calendering roller group and the second calendering roller group.

17. The method for preparing ultra-thin rolled glass for solar cells according to claim 1, wherein: The viscosity of the glass liquid entering the first rolling roller group is 10 2.78 Pa·S~10 3.22 Pa.S.

18. The method for preparing ultra-thin rolled glass for solar cells according to claim 1, wherein: The viscosity of the glass entering the second rolling roller group is 10 4.71 Pa·S~10 5.71 Pa.S.

19. The method for preparing ultra-thin rolled glass for solar cells according to claim 1, wherein: The annealing process includes annealing in five zones, which are: a soaking zone, an important cooling zone, a slow cooling zone, a fast cooling zone and a rapid cooling zone.

20. The method for preparing ultra-thin rolled glass for solar cells according to claim 19, wherein: The temperature range of the soaking zone is 550-650℃; the temperature range of the important cooling zone is 450-550℃, and the cooling rate of the glass ribbon is controlled at 3.5-6℃ / m; the temperature range of the slow cooling zone is 320-450℃, and the cooling rate of the glass ribbon is controlled at 4-7.5℃ / m; the temperature range of the rapid cooling zone is 180-280℃, and the cooling rate of the glass ribbon is controlled at 6-10℃ / m; the temperature range of the rapid cooling zone is 70-150℃, and the cooling rate of the glass ribbon is controlled at 9-14℃ / m.

21. A manufacturing device for the method for manufacturing ultra-thin rolled glass for solar cells according to any one of claims 1 to 20, characterized in that: The preparation device includes a batching device, a melting furnace, a forming device, and an annealing furnace, wherein the melting furnace is provided with a bubbling clarification device, the forming device is a multi-stage roller forming device, and the annealing furnace includes multiple annealing zones.

22. The device for preparing ultra-thin rolled glass for solar cells according to claim 21, characterized in that: A bubbling clarification device is installed near the hot spot of the melting furnace. The bubbling clarification device is single-row or multi-row.

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