Preparation method and preparation device of ultrathin rolled glass for solar cell

Abstract

The invention relates to a preparation method and a preparation device of ultrathin rolled glass for a solar cell. Compared with an existing rolled glass preparation technology, according to the particularity of the ultra-thin rolled glass for the solar cell, technical innovation is carried out on a plurality of procedures, and a brand-new ultra-thin rolled glass preparation technology is formed. The method specifically comprises the following steps: in a glass component selection and batching process, optimally designing glass components, and improving the impact resistance of the ultrathin rolled glass; in the melting and clarifying process, the formula of a clarifying agent is improved, and the combustion atmosphere of a melting furnace is set as oxidizing atmosphere, so that efficient melting and clarifying of molten glass are realized; in the forming procedure, a multi-stage calendaring forming process is adopted, and forming of the ultrathin glass tape with the small thickness difference is achieved; in the annealing process, the annealing process of finely controlling the temperature of each annealing area and accurately controlling the cooling speed of the glass tape is adopted, so that the precise annealing of the ultrathin rolled glass tape is realized. The ultrathin rolled glass produced by the 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 particularly to a preparation method and a preparation device for ultra-thin rolled glass for solar cells. Background Art

[0002] Solar power generation has the advantages of rich energy resources, mature power generation technology, and low power generation cost, and has developed into an important new energy industry globally. Solar power generation modules are the core components of solar power generation systems. China is the global production and manufacturing center of solar power generation modules. In 2023, the output of solar power generation modules in China has reached 499GW, accounting for about 84.6% of the global total output. Solar power generation modules are composed of multiple solar cells. Glass is an important component of solar cells, and its function is to block moisture and air and prevent the battery chips from being eroded and oxidized. According to statistics, the annual demand for glass for solar cells is expected to be 33 million tons, and it will increase year by year with the increase in the demand for solar power generation modules.

[0003] Glass for solar cells is usually made by deep processing of rolled glass. The existing method for producing rolled glass is to roll the molten glass liquid into shape at one time. By using the one-time rolling forming process, the industrial production of rolled glass with a thickness of 1.6 mm or more can be realized. If the thickness of the rolled glass can be further reduced on the basis of 1.6 mm, not only can the weight of the solar cell module be significantly reduced, the application scenarios of the solar cell module be increased, the light transmittance of the rolled glass be improved, the power generation efficiency of the solar cell be effectively increased, but also the raw material consumption and fuel consumption required for the production of the rolled glass can be reduced, thereby reducing the production cost and effectively saving resources. However, when using the existing production process to produce rolled glass with a thickness of less than 1.6 mm, the thickness difference of the glass will be relatively large, and the following problems will occur: First, when it is necessary to coat a film on the glass surface, the commonly used roll coating process cannot be used, because when the roll coating process is used to coat a film on glass with a large thickness difference, the thickness uniformity of the film layer is poor, which affects the light transmittance of the glass, and using other coating processes will significantly increase the production cost; Second, the ultra-thin rolled glass with a large thickness difference has poor bending resistance and impact resistance, and when laminating the glass plate and other components together during the preparation of solar cells, the problem of the glass plate bursting easily occurs, resulting in the scrapping of solar cells.

[0004] Therefore, how to realize 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 to be solved in the industry. Summary of the Invention

[0005] To solve the above technical problems, based on the existing production process of calendered glass for solar cells, the inventor team innovated multiple processes to form a new preparation method. The ultra-thin calendered glass prepared by this preparation method has the characteristics of small thickness difference, excellent impact resistance, and high light transmittance.

[0006] The specific technical solution of the present invention is as follows: A preparation method of ultra-thin calendered glass for solar cells, comprising: Glass component selection and batching process: Weigh each raw material according to the component design suitable for ultra-thin calendered glass, mix each raw material to form a batch material, and convey the batch material to the melting furnace; Melting and fining process: Use a melting furnace with a bubbling fining device to melt and fine the batch material. The melted and fined glass liquid flows into the forming device; Forming process: Form the glass liquid into an ultra-thin glass ribbon through a multi-stage continuous roll pressing forming device, and send the glass ribbon into the annealing furnace; Annealing process: Anneal the glass ribbon through multiple annealing zones with independently controllable temperatures; Cutting process: Inspect and cut the annealed glass ribbon, and then pack it into the warehouse or directly enter the deep processing process.

[0007] The following is an explanation of each of the above processes one by one.

[0008] Glass component selection and batching process: Preferably, in the present invention, by appropriately reducing the contents of Na2O and CaO in the existing calendered glass components for solar cells, increasing the contents of SiO2 and Al2O3, and adding oxides such as K2O, B2O3, and ZrO2, a new glass component is formed. This component can reduce the thermal expansion coefficient of the glass, increase the mechanical properties and impact resistance of the glass; it can make the viscosity-temperature gradient of the glass smaller, which is beneficial to the implementation of the multi-stage calendering forming process; it can reduce the precipitation of Na2O in the glass under high-temperature and high-humidity use environments, and inhibit and reduce the potential-induced degradation (PID) effect of solar cells. In addition, in the present invention, by controlling the ratio of the average particle size of soda ash introducing Na2O to the average particle size of silica sand introducing SiO2, the batch material after mixing has better uniformity, achieving a batch material mean square deviation ≤ 0.28, thereby improving the melting quality.

[0009] Melting and fining process: Preferably, the melting and fining process of the present invention includes the following improvements: adding a fining agent to the batch material, and setting a bubbling fining device in the melting furnace to reduce the number of bubbles in the glass, improve the fining quality of the glass liquid, and enhance the glass quality; adjusting the combustion atmosphere in the melting furnace to an oxidizing atmosphere to increase the proportion of Fe 2+ Converted to Fe 3+ and improve the light transmittance of the glass in the wavelength range of 380 - 1100 nm.

[0010] Forming process: Preferably, the present invention adopts a brand-new multi-stage continuous calendering forming process to form the glass liquid into an ultra-thin glass ribbon. First, the glass liquid flowing out of the melting furnace enters the runner. Next, the glass liquid after passing through the runner flows into the first calendering unit through the lip brick. The viscosity of the glass liquid when entering the first calendering unit is controlled by the heating and cooling devices laid in the runner. The glass liquid is calendered by the first calendering unit to form a glass ribbon with a first thickness, and the first thickness is preferably 2.5 mm to 5.0 mm. After that, the glass ribbon passing through the first calendering unit enters the second calendering unit via the carrying roller. The viscosity of the glass ribbon when entering the second calendering unit is controlled by the heating and cooling devices arranged between the first and second calendering units. The glass ribbon is calendered by the second calendering unit to form a glass ribbon with a second thickness, and the second thickness is preferably 0.5 mm to 2.0 mm, more preferably less than 1.6 mm.

[0011] Preferably, a throttling device is arranged at the end of the runner. More preferably, the throttling device is a throttling roller arranged above the end of the runner. 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 runner and the rotation speed of the throttling roller, so as to realize the flow limiting of the glass liquid.

[0012] Preferably, the throttling roller and the upper and lower rollers of the first calendering unit are calendering rollers with smooth surfaces, the upper roller of the second calendering unit is a calendering roller with a preset roughness, and the lower roller is a calendering roller with a preset pattern. Compared with the single-stage calendering forming, the multi-stage continuous calendering forming can meet the production requirements of ultra-thin calendered glass with a small thickness difference.

[0013] Annealing process: Preferably, the annealing process of the present invention adopts a method of precisely controlling the annealing temperature in each area of the annealing furnace and precisely controlling the cooling rate of the glass ribbon, significantly reducing the residual stress in the glass, effectively avoiding problems such as deformation and cracking of the glass ribbon during the annealing process, and realizing the stable and efficient production of high-quality ultra-thin calendered glass.

[0014] Cutting process: The annealed glass ribbon undergoes processes such as on-line quality inspection, cutting, and edge breaking and slicing to obtain glass products of the required size. After the glass products are packaged, they are stored in the warehouse or directly enter the deep processing process.

[0015] The present invention also relates to the preparation device used in the above preparation method. The preparation device includes a batching device, a melting furnace, a forming device, an annealing furnace, and a cutting device, wherein the forming device includes a multi-stage continuous calendering roll group and its related devices. The above device can be used for the production of high-quality ultra-thin calendered glass.

[0016] The present invention has made technological innovations in multiple processes of the preparation method of rolled glass for solar cells, forming a brand-new forming preparation process, which can achieve the following beneficial effects: By optimizing the design of the glass composition, the impact resistance of the ultra-thin rolled glass is improved, and the PID effect of the solar cell is reduced; By optimizing the design of the fining agent and adjusting the combustion atmosphere of the melting furnace, efficient fining of the glass liquid is achieved, and Fe in the glass is promoted to 2+ transform into Fe 3+ , improving the light transmittance of the glass; Adopting a multi-stage continuous rolling forming process, ultra-thin rolled glass with a small thickness difference is formed. The above-mentioned multiple process innovations are combined, and finally the industrial production of high-quality ultra-thin rolled glass with a thickness of less than 1.6 mm is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Appendix Figure 1 Schematic diagram of the overall process flow of the preparation process of ultra-thin rolled glass for solar cells.

[0018] Appendix Figure 2 Schematic diagram of the melting furnace in the melting and fining process.

[0019] Appendix Figure 3 Schematic diagram of the bubbling fining device of the melting furnace in the melting and fining process.

[0020] Appendix Figure 4 Schematic diagram of the forming device in the forming process.

[0021] Appendix Figure 5 Schematic diagram of the annealing furnace in the annealing process.

[0022] Reference Signs: Melting furnace 100; Batch charger 101; Throat 102; Cross-channel 103; Branch channel 104; Bubbling fining device 105; Throttling roll group 10; Throttling roll frame 11; Throttling roll 12; First rolling roll group 20; First frame 21; First upper rolling roll 22; First lower rolling roll 23; Second rolling roll group 30; Second frame 31; Second upper rolling roll 32; Second lower rolling roll 33; Lip brick 40; Support roll 51; Traction roll 52; First heating device 61; Second heating device 62; First cooling device 63; Second cooling device 64; Glass liquid 71; Glass ribbon 72; Runner 80; First direction X; Second direction Y, Homogenization zone 301; Important cooling zone 302; Slow cooling zone 303; Fast cooling zone 304; Rapid cooling zone 305. DETAILED DESCRIPTION OF THE INVENTION

[0023] Next, in conjunction with the accompanying drawings, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the above embodiments fall within the protection scope of the present invention.

[0024] Specifically, the present invention provides a method for preparing ultra-thin rolled glass for solar cells. As Figure 1 shown, the glass preparation method includes the following processes: Glass component selection and batching process: Weigh each component according to the component design suitable for ultra-thin rolled glass, mix each component to form a batch material, and transport the batch material to the melting furnace; Melting and clarification process: Use a melting furnace with a bubbling clarification device to melt and clarify the batch material, and the melted and clarified glass liquid flows into the forming device; Forming process: Form the glass liquid into an ultra-thin glass ribbon through a two-stage continuous roll pressing forming device, and send the glass ribbon into the annealing furnace; Annealing process: Anneal the glass ribbon through multiple annealing zones with independently controllable temperatures; Cutting process: Detect and cut the annealed glass ribbon, and then package it into the warehouse or directly enter the deep processing process.

[0025] Next, each process will be described one by one.

[0026] Glass component selection and batching process The glass for solar cells needs to play a protective role for the power generation components in a variety of different usage scenarios (such as high temperature, high humidity, and sand impact environments). Therefore, the glass should have high impact resistance and effectively reduce the PID effect of solar cells.

[0027] Preferably, the glass components used in the present invention are calculated by weight percentage and include: 72.4% - 74.5% of SiO2, 0.9% - 3.8% of Al2O3, 0.009% - 0.012% of Fe2O3, 2.2% - 4.0% of CaO, 3.8% - 5.2% of MgO, 10% - 11.5% of Na2O, 0.5% - 1.2% of B2O3, 0.5% - 2.5% of K2O, 0.05% - 1.0% of ZrO2, where B2O3 + ZrO2 is 0.8% - 2.6%, and K2O + Na2O is 11 - 13%.

[0028] Compared with the conventional rolled glass composition for solar cells, the above glass composition reduces the contents of Na2O and CaO, increases the contents of SiO2 and Al2O3, and additionally adds oxides such as K2O, B2O3, and ZrO2. Through the adjustment of the above components and their contents, it is beneficial for forming production using a multi-stage rolling process, improves the thermal stability, chemical stability, and mechanical strength of the glass, enhances the impact resistance performance, strengthens the protection of the solar cell module, extends the service life of the solar cell module, and effectively reduces the PID effect of the solar cell.

[0029] In addition, the uniformity of the glass batch directly affects 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 - 0.8, more preferably 0.72 - 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 ≤ 0.28.

[0030] Weigh each raw material in the batch according to the above glass composition design. After weighing, each raw material is conveyed to a mixer by an aggregate belt for mixing. The uniformly mixed batch is sent to the kiln head bin through a belt. Preferably, a certain proportion of cullet is added to the batch.

[0031] Melting and fining process As a preference, as Figure 2 and Figure 3 shown, after the batch is sent to the kiln head bin, the batch is pushed into the melting furnace 100 through the feeder 101 under the kiln head bin. The batch is melted, fined, and homogenized in the melting furnace 100 to form a uniform glass melt. The glass melt flows into the cross-channel 103 after passing through the throat 102, and then is conveyed to the forming device through each branch channel 104 for forming. To improve the fining effect of the glass melt, it is preferred to add a fining agent to the batch. In addition, the glass melt can be intensively bubbled and fined through the bubbling fining device 105. The combustion atmosphere in the melting furnace is preferably an oxidizing atmosphere to reduce the Fe 2+ content in the glass, thereby improving the light transmittance of the glass.

[0032] In some embodiments of the present invention, the glass fining agent is sodium pyroantimonate, and the dosage of sodium pyroantimonate accounts for 0.1 - 0.35% of the weight of the batch, preferably 0.22 - 0.3%.

[0033] In some embodiments of the present invention, a composite fining agent is selected as the glass fining agent. The components of the composite fining agent include antimony trioxide, sodium sulfate, sodium nitrate, etc. Among them, the dosage of antimony trioxide accounts for 0.1-0.16% of the weight of the batch material, the dosage of sodium nitrate accounts for 1.0-2.0% of the weight of the batch material, and the dosage of sodium sulfate accounts for 0.8-1.8% of the weight of the batch material. Preferably, the dosage of antimony trioxide accounts for 0.12-0.14% of the weight of the batch material, the dosage of sodium nitrate accounts for 1.1-1.5% of the weight of the batch material, and the dosage of sodium sulfate accounts for 1.0-1.3% of the weight of the batch material.

[0034] In some embodiments of the present invention, at least one row of bubbling fining devices 105 is arranged near the hot spot of the melting furnace. The gas introduced into the glass melt through the bubbling fining device 105 is compressed air, oxygen, etc., and oxygen is preferred.

[0035] In some embodiments of the present invention, the combustion atmosphere of the melting furnace is preferably an oxidizing atmosphere, and the air excess coefficient in the furnace is ≥1.2.

[0036] Forming process Preferably, as Figure 4 shown, the forming device includes a throttling roll group 10, a first calender roll group 20, a second calender roll group 30, a lip brick 40 and a support roll 51. The throttling roll group 10, the first calender roll group 20 and the second calender roll group 30 are arranged in sequence along the first direction X. The throttling roll group 10 includes a throttling roll frame 11, throttling rolls 12 arranged at intervals along the second direction Y on the throttling roll frame 11, and a driving device (not shown in the figure) for driving the throttling rolls 12 to rotate. The first calender roll group 20 includes a first frame 21, a first calender upper roll 22 and a first calender lower roll 23 arranged at intervals along the second direction Y on the first frame 21, and a first driving device (not shown in the figure) for driving the first calender upper roll 22 and the first calender lower roll 23 to rotate in opposite directions. The second calender roll group 30 includes a second frame 31, a second calender upper roll 32 and a second calender lower roll 33 arranged at intervals along the second direction Y on the second frame 31, and a second driving device (not shown in the figure) for driving the second calender upper roll 32 and the second calender lower roll 33 to rotate in opposite directions. The support roll 51 is arranged between the first calender roll group 20 and the second calender roll group 30 and is used for conveying the glass ribbon 72.

[0037] In some embodiments of the present invention, the distance h1 between the lower bus of the throttling roll 12 and the bottom surface of the runner, the rotational speed of the throttling roll 12, the distance h2 between the first calender upper roll 22 and the first calender lower roll 23, and the rotational speeds of the first calender upper roll 22 and the first calender lower roll 23 meet the following conditions: Preferably 。The thickness of the glass ribbon after being roll-pressed by the first calender roll set 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.

[0038] The distance h2 between the first upper calender roll 22 and the first lower calender roll 23, and the rotational speeds of the first upper calender roll 22 and the first lower calender roll 23 、the distance h3 between the second upper calender roll 32 and the second lower calender roll 33, and the rotational speeds of the second upper calender roll 32 and the second lower calender roll 33 Meet the following conditions: , preferably , more preferably 。The thickness of the glass ribbon after being roll-pressed by the second calender roll set 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.

[0039] As Figure 4 shown, a first heating device 61 and a first cooling device 63 are provided between the throttling roll set 10 and the first calender roll set 20, and a second heating device 62 and a second cooling device 64 are provided between the first calender roll set 20 and the second calender roll set 30. The first heating device 61 and the first cooling device 63 are provided above and / or on the side of the runner 80. The second heating device 62 and the second cooling device 64 are provided above and / or on the side and / or below the carrying roll 51.

[0040] When the molten glass 71 passes through the throttling roller group 10, if the temperature of the molten glass 71 in the runner 80 drops too quickly, the phenomenon of sticking to the rollers will occur during the first calendering, that is, the molten glass 71 adheres to the surfaces of the first upper calendering roller 22 and the first lower calendering roller 23. This will affect the distance between the first upper calendering roller 22 and the first lower calendering roller 23, making it impossible for the glass belt 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, when the temperature is relatively low, the first heating device 61 can be used to heat the molten glass 71, and when the temperature is relatively high, the first cooling device 63 can be used to cool the molten glass 71. When the temperature of the molten glass 71 is appropriate, no heating or cooling intervention is carried out. The above process can ensure that the molten glass 71 has fluidity and meets the viscosity required for calendering by the first calendering unit 20. After the molten glass 71 is roll-pressed by the first calendering roller group 20, a solid glass belt 72 is formed. At this time, if the temperature of the glass belt 72 drops too quickly, it is likely to cause the glass belt 72 to shrink and deform rapidly, and it cannot be smoothly conveyed to the second calendering roller group 30 for further forming; if the temperature of the glass belt 72 is too high, the glass belt 72 will soften and deform, and it is also impossible to smoothly convey the glass belt to the second calendering roller group 30 for further forming. In the embodiment of the present invention, according to actual needs, the second heating device 62 and the second cooling device 64 are used to heat or cool the glass belt 72 or not to intervene, so that the glass belt 72 can be maintained at an appropriate temperature, and then the glass belt 72 can be smoothly conveyed to the second calendering roller group 30 and meet the viscosity required for forming. In addition, keeping the glass belt 72 within a suitable viscosity range when it enters the second calendering roller group 30 can also ensure that the surface roughness of the glass belt 72 after being formed by the second calendering roller group 30 matches the preset roughness, so as to avoid self-polishing of the glass surface due to too high a temperature of the glass belt 72, which affects the light transmittance of the glass.

[0041] Preferably, the viscosity of the molten glass when it enters the first calendering roller group is 10 1.89 Pa·S to 10 4.14 Pa·S, more preferably 10 2.59 Pa·S to 10 3.65 Pa·S, further preferably 10 2.78 Pa·S to 10 3.22 Pa·S.

[0042] Preferably, the viscosity of the glass belt when it enters the second calendering roller group is 10 3.65 Pa·S to 10 6.81 Pa·S, more preferably 10 4.03 Pa·S to 10 6.23 Pa·S, further preferably 10 4.71 Pa·S to 10 5.71 Pa·S.

[0043] In some embodiments of the present invention, the throttling roller 12, the first calender upper roller 22, and the second calender lower roller 23 are all smooth surface calender rollers, so that the surface of the glass ribbon 72 after one-time calendering is a smooth surface. Such a setting can make the calendering resistance of the throttling roller and the one-time calendering smaller.

[0044] The surface of the second calender upper roller 32 is a surface with a preset roughness, and the surface of the second calender lower roller 33 is a patterned surface with a preset pattern, so that after the glass ribbon 72 undergoes the second calendering, the upper surface is a suede surface and the lower surface is an embossed surface. Such a setting can improve the light transmittance of the glass ribbon 72. Preferably, the surface roughness of the second calender upper roller is 5 μm to 7 μm.

[0045] When the glass liquid 71 enters the throttling roller 12 of the throttling roller group 10, the driving device drives the throttling roller 12 to rotate counterclockwise relative to the flowing direction of the glass liquid to limit the flow of the glass liquid 71. The throttled glass liquid 71 flows into the space between the first calender upper roller 22 and the first calender lower roller 23 of the first calender roller group 20 through the lip brick 40. The first driving device drives the first calender upper roller 22 and the first calender lower roller 23 to rotate in opposite directions to roll the glass liquid 71 again, so that the glass liquid 71 is formed into a glass ribbon 72. The glass ribbon 72 formed by rolling through the first calender roller group is conveyed to the space between the second calender upper roller 32 and the second calender lower roller 33 of the second calender roller group 30 through the supporting roller 51. The second driving device drives the second calender upper roller 32 and the second calender lower roller 33 to rotate in opposite directions to further roll the glass ribbon 72, so that the thickness of the glass ribbon 72 is further reduced. Through the above multi-stage and step-by-step rolling, a glass ribbon with a small thickness difference is obtained. The traction roller 52 feeds the glass ribbon 72 formed by multi-stage rolling into the annealing furnace for annealing.

[0046] Annealing process Preferably, 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: As Figure 5 shown, the annealing furnace includes five zones, which are successively the soaking zone 301, the important cooling zone 302, the slow cooling zone 303, the rapid cooling zone 304, and the rapid cooling zone 305. The annealing of the glass ribbon 72 is achieved by precisely controlling the cooling rate of the glass ribbon.

[0047] The soaking zone 301 is used to keep the temperature of the glass ribbon 72 uniform after it enters the annealing furnace and control the temperature at the upper limit of the annealing temperature of the glass. The temperature range of the soaking zone is about 550 - 650 °C.

[0048] 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.

[0049] The slow cooling zone 303 is the key area for generating temporary stress. This area slowly reduces the temperature of the glass ribbon to prevent excessive temporary stress from causing the glass to crack. The temperature range of the slow cooling zone is approximately 320 - 450 °C, and the cooling rate is controlled at 4 - 7.5 °C / m, preferably 5 - 7 °C / m, and more preferably 5.8 - 6.5 °C / m.

[0050] The rapid cooling zone 304 allows the glass ribbon to cool naturally. The temperature range is approximately 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.

[0051] The rapid cooling zone 305 uses forced air cooling to rapidly cool the glass ribbon. The temperature range of the rapid cooling zone is approximately 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.

[0052] Cutting process The annealed glass ribbon can be processed through online quality inspection, cutting, edge breaking and slicing according to the requirements of the glass size by the using manufacturer to obtain the glass products, which are then packaged and stored in the warehouse or directly enter the deep processing process.

[0053] It should be noted that implementing the present invention does not require simultaneously adopting all the above-mentioned preferred methods or achieving all the above-mentioned advantages.

[0054] Examples Examples 1 - 15 are technical solutions for preparing rolled glass with different thicknesses using the specific implementation manners of the present invention. Different technical parameters are selected for the forming process in each example. Comparative Example 1, Comparative Example 2, and Comparative Example 3 are technical solutions for rolled glass with thicknesses of 1.6 mm, 1.5 mm, and 1.3 mm produced by the existing first - stage rolling forming process, respectively. The technical parameters of the forming process and the specific forming thicknesses of Examples 1 - 15 and Comparative Examples 1 - 3 are shown in Table 1. After forming, the glass is annealed and cut, and then the thickness and thickness difference are tested.

[0055] The tests for glass thickness and thickness difference are carried out in accordance with the requirements of the national standard GB / T 30984 - 2015 "Glass for solar energy - Part 1: Ultra - clear embossed glass".

[0056] Table 1 Properties of rolled glass in examples and comparative examples It can be seen from Table 1 that the thickness difference of the 1.6 - mm - thick rolled glass produced by using the multi - stage continuous rolling forming process of the present invention is significantly better than that of the 1.6 - mm - thick rolled glass produced by using the technical solution of Comparative Example 1.

[0057] In addition, it can also be seen from Table 1 that the technical solution of the present invention can produce ultra-thin calendered glass with a small thickness difference of less than 1.6 mm. When meeting the requirements of the multi-stage calendering forming process parameters of "", , ", the thickness difference of the 1.5-mm calendered glass produced by the technical solution of the present invention is between 0.14 mm and 0.19 mm, which is better than that of the 1.5-mm calendered glass produced by the technical solution of Comparative Example 2; the thickness difference of the 1.3-mm calendered glass produced by the technical solution of the present invention is between 0.18 mm and 0.24 mm, which is better than that of the 1.3-mm calendered glass produced by the technical solution of Comparative Example 3. When deviating from the above process parameter requirements, the thickness difference will increase. Therefore, the application of the technical solution of the present invention can achieve the production of high-quality calendered glass with a thickness of less than 1.6 mm.

[0058] The above specific embodiments are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are all included in the protection scope of the present invention.

Claims

1. A preparation method of ultra-thin rolled glass for solar cells, characterized in that The preparation method includes the following processes: Glass component selection and batching process: Weigh each raw material according to the component design suitable for ultra-thin rolled glass, mix the raw materials to form a batch, and convey the batch to the melting furnace; Melting and fining process: Use a melting furnace with a bubbling fining device to melt and fine the batch. The melted and fined glass liquid flows into the forming device; Forming process: Form the glass liquid into an ultra-thin rolled glass ribbon through a multi-stage continuous roll pressing forming device. In the first-stage rolling, the glass liquid is rolled into a glass ribbon with a first thickness, and in the second-stage rolling, the glass ribbon is rolled into a glass ribbon with a second thickness, where the second thickness is less than the first thickness. The ultra-thin rolled glass ribbon after multi-stage roll pressing is sent into the annealing furnace; Annealing process: Anneal the ultra-thin rolled glass ribbon through multiple independently temperature-controllable annealing zones.

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

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

4. The preparation method of the ultra-thin rolled glass for solar cells according to claim 3, characterized in that, In the composite fining agent, antimony trioxide accounts for 0.12 - 0.14% of the weight of the batch, sodium nitrate accounts for 1.1 - 1.5% of the weight of the batch, and sodium sulfate accounts for 1.0 - 1.3% of the weight of the batch.

5. The preparation method of the ultra-thin calendered glass for solar cells according to claim 1, wherein, The gas introduced into the glass liquid by the bubbling fining device is oxygen.

6. The preparation method of the ultra-thin rolled glass for solar cells according to claim 1, characterized in that, The described forming device includes a first rolling roll group and a second rolling roll group. The first rolling roll group includes a first upper rolling roll and a first lower rolling roll, and the second rolling roll group includes a second upper rolling roll and a second lower rolling roll.

7. The preparation method of the ultra-thin calendered glass for solar cells according to claim 6, characterized in that, The distance h2 between the first upper calender roll and the first lower calender roll, and the rotational speeds of the first upper calender roll and the first lower calender roll 、the distance h3 between the second upper calender roll and the second lower calender roll, and the rotational speeds of the second upper calender roll and the second lower calender roll Satisfy: .

8. The preparation method of the ultra-thin rolled glass for solar cells according to claim 7, characterized in that The distance h2 between the first upper calender roll and the first lower calender roll, and the rotational speeds of the first upper calender roll and the first lower calender roll the distance h3 between the second upper calender roll and the second lower calender roll, and the rotational speeds of the second upper calender roll and the second lower calender roll Satisfy: .

9. The preparation method of the ultra-thin rolled glass for solar cells according to claim 7, characterized in that, The distance h2 between the first calender upper roll and the first calender lower roll, and the rotational speeds of the first calender upper roll and the first calender lower roll the distance h3 between the second calender upper roll and the second calender lower roll, and the rotational speeds of the second calender upper roll and the second calender lower roll Satisfy: .

10. The preparation method of the ultra-thin rolled glass for solar cells according to any one of claims 6-9, characterized in that, The multi-stage continuous roll pressing forming device includes a throttling device. The throttling device is provided with a throttling roll, and the throttling roll realizes the flow limiting of the glass liquid.

11. The preparation method of the ultra-thin rolled glass for solar cells according to claim 10, characterized in that, The multi-stage continuous roll pressing forming device includes a runner connecting the melting furnace. The throttling roll is arranged above the end of the runner. The flow rate of the glass liquid is controlled by the distance between the lower bus of the throttling roll and the bottom surface of the runner and the rotation speed of the throttling roll to realize the flow limiting of the glass liquid.

12. The preparation method of the ultra-thin rolled glass for solar cells according to claim 11, characterized in that, The distance h1 between the lower bus of the throttling roller and the bottom surface of the runner, the rotational speed of the throttling roller the distance h2 between the first calendering upper roller and the first calendering lower roller, the rotational speeds of the first calendering upper roller and the first calendering lower roller Satisfy: .

13. The preparation method of the ultra-thin rolled glass for solar cells according to claim 12, characterized in that, The distance h1 between the lower bus of the throttling roller and the bottom surface of the runner, the rotational speed of the throttling roller The distance h2 between the first calendering upper roller and the first calendering lower roller, the rotational speeds of the first calendering upper roller and the first calendering lower roller Satisfy: .

14. The preparation method of the ultra-thin rolled glass for a solar cell according to claim 13, wherein, The distance h1 between the lower busbar of the throttling roller and the bottom surface of the runner, and the rotational speed of the throttling roller The distance h2 between the first calendering upper roller and the first calendering lower roller, and the rotational speeds of the first calendering upper roller and the first calendering lower roller Satisfy: .

15. The preparation method of the ultra-thin calendered glass for solar cells according to claim 6, characterized in that, There is a supporting roll between the first rolling roll group and the second rolling roll group.

16. The preparation method of the ultra-thin rolled glass for solar cells according to claim 10, characterized in that, There is a first heating device and a first cooling device between the throttling roll group and the first rolling roll group, and a second heating device and a second cooling device between the first rolling roll group and the second rolling roll group.

17. The preparation method of the ultra-thin rolled glass for a solar cell according to claim 16, characterized in that, The first heating device and the first cooling device are arranged above and / or on the side of the runner for conveying the glass liquid between the throttling roll group and the first rolling roll group.

18. The preparation method of the ultra-thin rolled glass for solar cells according to claim 16, characterized in that, The second heating device and the second cooling device are arranged above and / or on the side and / or below the supporting roll between the first rolling roll group and the second rolling roll group.

19. The preparation method of the ultra-thin rolled glass for solar cells according to claim 6, characterized in that, The viscosity of the molten glass entering the first calender roll group is 10 2.78 Pa·S to 10 3.22 Pa·S.

20. The preparation method of the ultra-thin rolled glass for solar cells according to claim 6, characterized in that, The viscosity of the glass entering the second calender roll group is 10 4.71 Pa·S to 10 5.71 Pa·S.

21. The preparation method of the ultra-thin rolled glass for solar cells according to claim 1, characterized in that, The annealing process includes annealing in five zones, namely: soaking zone, important cooling zone, slow cooling zone, rapid cooling zone and extremely rapid cooling zone.

22. The preparation method of the ultra-thin rolled glass for solar cells according to claim 21, characterized in that, The temperature range of the soaking zone is 550 - 650 °C; the temperature range of the important cooling zone is 450 - 550 °C, and the cooling rate of the glass ribbon is controlled at 3.5 - 6 °C / m; the temperature range of the slow cooling zone is 320 - 450 °C, and the cooling rate of the glass ribbon is controlled at 4 - 7.5 °C / m; the temperature range of the rapid cooling zone is 180 - 280 °C, and the cooling rate of the glass ribbon is controlled at 6 - 10 °C / m; the temperature range of the extremely rapid cooling zone is 70 - 150 °C, and the cooling rate of the glass ribbon is controlled at 9 - 14 °C / m.

23. Preparation device for the preparation method of the ultra-thin calendered glass for solar cells according to any one of claims 1-22, characterized in that, The preparation device includes a batching device, a melting furnace, a forming device, and an annealing furnace. The melting furnace is equipped with a bubbling clarification device. The forming device is a multi-stage roll pressing forming device, and the annealing furnace includes multiple annealing zones.

24. The manufacturing apparatus of the ultra-thin rolled glass for a solar cell according to claim 23, characterized in that, A bubbling clarification device is installed near the hot spot of the melting furnace, and the bubbling clarification device can be single-row or multi-row.

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