Technology for enhancing transmittance of ultra-white float photovoltaic panel glass

Abstract

The invention discloses a technology for enhancing transmittance of ultra-white float photovoltaic panel glass. The technology comprises the following steps: cleaning impurities such as oil stains and glass powder on the surface of the glass; preheating is conducted, specifically, the surface of the glass is preheated and heated, the preheating temperature ranges from 20 DEG C to 150 DEG C, and the plate temperature of a glue feeding roller is 30 DEG C; primary plating: uniformly coating the surface of the photovoltaic glass with the coating liquid through a roller, and controlling the temperature of a coating room to be 25 + / -8 DEG C, with the best effect at 23 DEG C; the humidity is controlled to be 30%-65%, and the effect of 48% is the best. According to the invention, an ultra-white float glass substrate is mainly adopted, a new production process technology for coating is researched and developed for the first time, the transmittance of float glass is enhanced, a glass coating panel product meets the application of a solar photovoltaic power station panel, the photoelectric conversion rate is better, and the performance transmittance is an excellent index of 94.7% or above.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon-based solar cells, and in particular to a process for enhancing the transmittance of ultra-white float photovoltaic panel glass. Background Art

[0002] Silicon-based solar cells are the most mature photovoltaic devices in the current photovoltaic market, and photovoltaic-coated glass is a key component. Since the band gap of silicon-based photovoltaic materials is 1.11.3 eV and the absorption onset is between 1000 and 1100 nm, photovoltaic-coated glass must have a sufficiently high transmittance within the 400 nm to 1100 nm range to ensure that more sunlight is absorbed by the silicon. There are many methods to improve the performance of photovoltaic cover glass, including: reducing the iron content in the original glass to reduce the absorption of light by iron ions; embossing the cover glass to improve the reflection and scattering path of light between the glass and the silicon plate, thereby increasing the silicon plate's light absorption; and coating the photovoltaic glass to utilize the principle of destructive interference to reduce its reflection of sunlight and improve its utilization rate.

[0003] At present, different coating solutions and different coating processes in the photovoltaic industry will have a great impact on the transmittance of finished photovoltaic coated glass. Among them, the relative humidity of the air has not received widespread attention. After entering the tempering furnace, the water molecules on the surface of the film layer are difficult to evaporate. After tempering, due to the presence of water molecules, the micropores on the surface of the film layer cannot be completely closed, leaving a small amount of micropores on the surface of the final finished photovoltaic coated glass. After being cleaned by the packaging washing machine and contacted with room temperature water, the coated glass plate surface fogs and absorbs moisture, resulting in a decrease in transmittance. The main manifestations are: under reflected light conditions, the plate is white; under transmitted light conditions, the plate is severely fogged. Comparing electron micrographs of coated glass after and after the packaging and cleaning process reveals that the porous silica structure is intact before the packaging and cleaning process. However, without heating, holes appear in the porous silica. Analysis reveals that this is due to the low water temperature during the packaging and cleaning process, which causes moisture absorption and delayed evaporation. This results in a smeared surface and low transmittance. Therefore, there is an urgent need to design a process to enhance the transmittance of ultra-clear float photovoltaic panel glass to address these issues. Summary of the Invention

[0004] The purpose of the present invention is to provide a process for enhancing the transmittance of ultra-white float photovoltaic panel glass. This technology is to study the influence of relative air humidity on the morphology and transmittance of finished photovoltaic coated glass. To further improve the transmittance of photovoltaic coated glass, relative air humidity must be regarded as an important key process control point.

[0005] By installing a water heating system in the packaging washing machine to increase the water temperature to above 60 degrees, and a wind heating system to heat it to above 60 degrees, the coated glass surface will not fog or get wet. Through deep processing, mass production and terminal data statistics of component factories, the coating yield rate can reach ≥99% and the transmittance can reach ≥94.7% ( Figure 1 ), which fully meets the product requirements.

[0006] When using ultra-clear float glass as the substrate for coated panels, the water temperature is adjusted by adjusting the packaging and washing machine and adding a water heating system, and an air heating system is installed to adjust the temperature process control requirements, so as to enhance the transmittance of the ultra-clear float photovoltaic panel glass and basically eliminate the above-mentioned defects.

[0007] In order to achieve the above object, the present invention provides the following technical solutions: A process for enhancing the transmittance of ultra-clear float photovoltaic panel glass comprises the following steps: A1 cleaning, cleaning oil stains, glass powder and other impurities on the glass surface; A2 preheating, preheating the glass surface, heating, preheating temperature is 20-150℃, the plate temperature of the feeding roller is 30℃; A3: During the first coating process, the coating liquid is evenly applied to the surface of the photovoltaic glass by rollers. The temperature of the coating room is controlled at 25±8℃, with 23℃ being the best. The humidity is controlled at 30%-65%, with 48% being the best. A4 solidification, bake the film on the glass surface, the curing temperature is 50℃-150℃; A5 secondary coating: The coating liquid is evenly applied to the surface of the photovoltaic glass by rollers. The temperature of the coating room is controlled at 25±8℃, with 23℃ being the best. The humidity is controlled at 30%-65%, with 48% being the best. A6 secondary curing: bake the film on the glass surface for secondary curing at a temperature of 100°C-200°C; A7 tempering, put into the tempering furnace for tempering, the temperature during tempering is 700℃; A8 cleaning, put it into the cleaning machine for cleaning, water temperature 60℃-100℃, wind heating 60℃-80℃; A9 inspection is to conduct full inspection or random inspection on the coated products according to the process requirements, mainly checking the performance, film surface, YT difference and other items.

[0008] Preferably, in said A1, said cleaning includes a disc brush and a water supply system, the water supply system includes 3 water tanks with separate circulation spray air filtration (levels): coarse, medium and high efficiency, and water is supplied to the disc brush.

[0009] Preferably, the line speed of A2 during preheating is 8-18 m / min, and the temperature range is room temperature - 60°C.

[0010] Preferably, in A3 and A5, both the first and second plating include a coating positioning section: glass positioning, correction position: Rough positioning: adjust the position of both sides of the glass in the previous process to ensure it is centered; Precise positioning: adjust the front, back, left and right positions to meet production needs.

[0011] Preferably, in the A3 plating, the coating speed is ≥5.5 pieces / min, and the gas source is ≥0.45 MPa.

[0012] Preferably, the A4 solid has a line speed of 8-18 m / min, a temperature range of room temperature to 300°C, a maximum conveying width of 1550 mm, and a heating device using an IR infrared medium-wave tube, including a heating section and a cooling section, with a total length of 15400 mm.

[0013] Preferably, in the A5, the coating speed is ≥5.5 pieces / min, and the gas source is ≥0.45 MPa.

[0014] Preferably, in the A6, the line speed is 8-18 m / min, the temperature range is room temperature to 300°C, The maximum conveying width is 1550mm, and the heating device uses IR infrared medium wave tube.

[0015] Preferably, in the A8, four water tanks are used for separate circulation spraying, wherein the water heating temperature is from room temperature to 100°C, and the wind heating temperature is from room temperature to 200°C.

[0016] In the above technical solution, the present invention provides a process for enhancing the transmittance of ultra-white float photovoltaic panel glass. The water temperature of the packaging and washing machine reaches above 60°C, the wind box temperature reaches above 60°C, and the transmittance of the finished photovoltaic coated glass produced in an environment with relative humidity is as follows: Figure 1 As shown by Figure 1 It can be seen that the transmittance of the finished photovoltaic coated glass obtained under low humidity conditions is significantly higher in the 450-950°C range than that obtained under high humidity, covering nearly the entire visible light range. Only in the near-infrared region is the transmittance slightly lower than that of the finished photovoltaic coated glass obtained under high humidity. This may be due to the rougher surface of the film layer of the finished photovoltaic coated glass obtained under high humidity. The longer wavelengths of the near-infrared region result in more reflections on the glass surface, resulting in increased transmittance in the long-wavelength region. The average transmittance of the finished photovoltaic coated glass obtained under low humidity conditions is 94.4%, which is also higher than that of the finished photovoltaic coated glass under high humidity conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0018] Figure 1 A schematic diagram of transmittance curves of finished photovoltaic coated glass under different relative air humidities provided in an embodiment of a process for enhancing transmittance of ultra-clear float photovoltaic panel glass according to the present invention.

[0019] Figure 2 A test chart provided for an embodiment of the process for enhancing transmittance of ultra-clear float photovoltaic panel glass according to the present invention.

[0020] Figure 3 Schematic diagram of an electron microscope image of coated glass that has not been through a packaging and cleaning machine, provided in an embodiment of the process for enhancing the transmittance of ultra-white float photovoltaic panel glass of the present invention.

[0021] Figure 4 This is an electron microscope image of coated glass that has passed through a packaging and cleaning machine, provided in an embodiment of the process for enhancing the transmittance of ultra-clear float photovoltaic panel glass according to the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0023] like Figure 1-4 As shown, an embodiment of the present invention provides a process for enhancing transmittance of ultra-white float photovoltaic panel glass, comprising the following steps: A1 cleaning, cleaning oil stains, glass powder and other impurities on the glass surface; A2 preheating, preheating the glass surface, heating, preheating temperature is 20-150℃, the plate temperature of the feeding roller is 30℃; A3: During the first coating process, the coating liquid is evenly applied to the surface of the photovoltaic glass by rollers. The temperature of the coating room is controlled at 25±8℃, with 23℃ being the best. The humidity is controlled at 30%-65%, with 48% being the best. A4 solidification, bake the film on the glass surface, the curing temperature is 50℃-150℃; A5 secondary coating: The coating liquid is evenly applied to the surface of the photovoltaic glass by rollers. The temperature of the coating room is controlled at 25±8℃, with 23℃ being the best. The humidity is controlled at 30%-65%, with 48% being the best. A6 secondary curing: bake the film on the glass surface for secondary curing at a temperature of 100°C-200°C; A7 tempering, put into the tempering furnace for tempering, the temperature during tempering is 700℃; A8 cleaning, put it into the cleaning machine for cleaning, water temperature 60℃-100℃, wind heating 60℃-80℃; A9 inspection is to conduct full inspection or random inspection on the coated products according to the process requirements, mainly checking the performance, film surface, YT difference and other items.

[0024] Preferably, in said A1, said cleaning includes a disc brush and a water supply system, the water supply system includes 3 water tanks with separate circulation spray air filtration (levels): coarse, medium and high efficiency, and water is supplied to the disc brush.

[0025] Preferably, the line speed of A2 during preheating is 8-18 m / min, and the temperature range is room temperature - 60°C.

[0026] Preferably, in A3 and A5, both the first and second plating include a coating positioning section: glass positioning, correction position: Rough positioning: adjust the position of both sides of the glass in the previous process to ensure it is centered; Precise positioning: adjust the front, back, left and right positions to meet production needs.

[0027] 5. Preferably, in the A3 plating, the coating speed is ≥5.5 pieces / min, and the gas source is ≥0.45 MPa.

[0028] Preferably, the A4 solid has a line speed of 8-18 m / min, a temperature range of room temperature to 300°C, a maximum conveying width of 1550 mm, and a heating device using an IR infrared medium-wave tube, including a heating section and a cooling section, with a total length of 15400 mm.

[0029] Preferably, in the A5, the coating speed is ≥5.5 pieces / min, and the gas source is ≥0.45 MPa.

[0030] Preferably, in the A6, the line speed is 8-18 m / min, the temperature range is room temperature to 300°C, The maximum conveying width is 1550mm, and the heating device uses IR infrared medium wave tube.

[0031] Preferably, in the A8, four water tanks are used for separate circulation spraying, wherein the water heating temperature is from room temperature to 100°C, and the wind heating temperature is from room temperature to 200°C.

[0032] This technical solution mainly adopts ultra-clear float glass substrate and develops a new coating production process technology for the first time, which realizes the enhanced transmittance of float glass. The glass coating panel products meet the application of solar photovoltaic power station panels, making the photoelectric conversion rate better, and its performance transmittance is an excellent indicator of more than 94.7%.

[0033] Example 1 A1 Cleaning Cleaning machine: cleans oil, glass powder and other impurities on the glass surface Main parameters: Cleaning glass thickness: 1.6-4.0mm; Disc brushes: 2 sets (4 rows); Wind Blades: 5 pairs; Water supply system: 3 water tanks with separate circulation spraying; Air filtration (level): coarse, medium, high efficiency; Maximum line speed: 18m / min; Glass deviation: ≤10mm; Operation mode: 24 hours continuous operation.

[0034] A2 Warm-up Preheating furnace: preheating the glass surface and raising the temperature Main parameters: Line speed: 8-18m / min; Temperature range: room temperature - 60℃; Maximum conveying width: 1400mm; Total length: 2800m.

[0035] A3 plating Coating machine: The coating liquid is evenly applied to the surface of photovoltaic glass (usually the air side) through a roller Main parameters: Processing thickness: 1.6-4.0mm; Conveying direction: short side first; Coating speed: ≥5.5 pieces / min (calculated based on 2.0mm-1000x2000mm); Coating yield rate: ≥99%; Maximum coating size: 1400x2500mm; Minimum coating size: 300x300mm; Air source: ≥0.45Mpa (clean compressed air).

[0036] A4 solid A coating curing furnace: bake the film on the glass surface and cure it Main parameters: Line speed: 8-18m / min; Temperature range: room temperature--300℃; Maximum conveying width: 1550mm; Heating device: IR medium wave tube; Number of sections: heating section + cooling section; Total length: 15400mm.

[0037] A5 Second Plating Coating machine: The coating liquid is evenly applied to the surface of photovoltaic glass (usually the air side) through a roller Main parameters: Processing thickness: 1.6-4.0mm; Conveying direction: short side first; Coating speed: ≥5.5 pieces / min (calculated based on 2.0mm-1000x2000mm); Coating yield rate: ≥99%; Maximum coating size: 1400x2500mm; Minimum coating size: 300x300mm; Air source: ≥0.45Mpa (clean compressed air).

[0038] A6 II Secondary coating and curing furnace: bake the film on the glass surface and cure it Main parameters: Line speed: 8-18m / min; Temperature range: room temperature--300℃; Maximum conveying width: 1550mm; Heating device: IR medium wave tube; Total length: 8000mm.

[0039] A7 tempered Place it in a tempering furnace for tempering, and the temperature during tempering is 700℃.

[0040] A8 Cleaning Cleaning machine: cleans oil, glass powder and other impurities on the glass surface Main parameters: Cleaning glass thickness: 1.6-4.0mm; Brush: 4 pairs; Wind Blades: 8 pairs; Water supply system: 4 water tanks with separate circulation spraying; Maximum line speed: 38m / min; Glass deviation: ≤10mm; Water heating temperature: room temperature--100℃; Wind heating temperature: room temperature - 200℃; Operation mode: 24 hours continuous operation.

[0041] A9 Inspection Inspection: Full inspection or random inspection is carried out on the coated products according to the process requirements, mainly inspecting the performance, film surface, YT difference and other items.

[0042] in: Connection: The glass is transferred to the next device through the connection, where a storage table is set up for emergency treatment. Main parameters: Line speed: adjustable according to production rhythm; Production abnormality: press the emergency stop switch; Storage quantity: ≤35 pieces; Stop position: adjustable front and back; Coating positioning section: glass positioning, position correction Main parameters: Rough positioning: adjust the position of both sides of the glass in the previous process to ensure it is centered; Precise positioning: adjust the front, back, left and right positions to meet production needs.

[0043] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A process for enhancing transmittance of ultra-clear float photovoltaic panel glass, characterized in that: The following steps are involved: A1 cleaning, cleaning oil stains, glass powder and other impurities on the glass surface; A2 preheating, preheating the glass surface, heating, preheating temperature is 20-150℃, the plate temperature of the feeding roller is 30℃; A3: During the first coating process, the coating liquid is evenly applied to the surface of the photovoltaic glass by rollers. The temperature of the coating room is controlled at 25±8℃, with 23℃ being the best. The humidity is controlled at 30%-65%, with 48% being the best. A4 solidification, bake the film on the glass surface, the curing temperature is 50℃-150℃; A5 secondary coating: The coating liquid is evenly applied to the surface of the photovoltaic glass by rollers. The temperature of the coating room is controlled at 25±8℃, with 23℃ being the best. The humidity is controlled at 30%-65%, with 48% being the best. A6 secondary curing: bake the film on the glass surface for secondary curing at a temperature of 100°C-200°C; A7 tempering, put into the tempering furnace for tempering, the temperature during tempering is 700℃; A8 cleaning, put it into the cleaning machine for cleaning, water temperature 60℃-100℃, wind heating 60℃-80℃; A9 inspection is to conduct full inspection or random inspection on the coated products according to the process requirements, mainly checking the performance, film surface, YT difference and other items.

2. The process for enhancing transmittance of ultra-clear float photovoltaic panel glass according to claim 1, characterized in that: In the A1, the cleaning includes a disc brush and a water supply system. The water supply system includes 3 water tanks with separate circulation spray air filtration (level): coarse, medium and high efficiency, and water is supplied to the disc brush.

3. The process for enhancing transmittance of ultra-clear float photovoltaic panel glass according to claim 1, characterized in that: The line speed of A2 during preheating is 8-18m / min, and the temperature range is from room temperature to -60℃.

4. The process for enhancing transmittance of ultra-clear float photovoltaic panel glass according to claim 1, characterized in that: In A3 and A5, both the first and second coating stages include the coating positioning stage: glass positioning and position correction. Rough positioning: adjust the position of both sides of the glass in the previous process to ensure it is centered; Precise positioning: adjust the front, back, left and right positions to meet production needs.

5. The process for enhancing transmittance of ultra-clear float photovoltaic panel glass according to claim 1, characterized in that: During the A3 plating, the coating speed is ≥5.5 pieces / min, and the gas source is ≥0.45 MPa.

6. The process for enhancing transmittance of ultra-clear float photovoltaic panel glass according to claim 1, characterized in that: The A4 solid has a line speed of 8-18m / min, a temperature range of room temperature to 300°C, a maximum conveying width of 1550mm, and a heating device using an IR infrared medium-wave tube, including a heating section and a cooling section, with a total length of 15400mm.

7. The process for enhancing transmittance of ultra-clear float photovoltaic panel glass according to claim 1, characterized in that: In the A5, the coating speed is ≥5.5 pieces / min, and the gas source is ≥0.45 MPa.

8. The process for enhancing transmittance of ultra-clear float photovoltaic panel glass according to claim 1, characterized in that: In the A6, the line speed is 8-18m / min, and the temperature range is room temperature to 300°C. The maximum conveying width is 1550mm, and the heating device uses IR infrared medium wave tube.

9. The process for enhancing transmittance of ultra-clear float photovoltaic panel glass according to claim 1, characterized in that: In the A8, four water tanks are used for separate circulation spraying, wherein the water heating temperature is from room temperature to 100°C, and the wind heating temperature is from room temperature to 200°C.

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