Building photovoltaic laminated glass and preparation method and application thereof

Abstract

The application provides a kind of building photovoltaic laminated glass and its preparation method, through structural improvement and the process and parameter adjustment of autoclave steaming pressure method, so that the crack of building photovoltaic laminated glass product reaches 0%, and bubble is discharged. Specifically, in structure, the cover is filled and clamped in the through hole, and the through hole will not produce negative pressure after vacuumizing; in process, first, control the temperature at about 70 DEG C in two steps, slowly vacuumize, and realize good bubble discharge effect in the laminated glass, then, under the condition of vacuumizing, heat to about 105 DEG C, close the vacuumizing, then, high temperature treatment, which can increase the coupling effect of PVB and glass, improve the adhesion, will not cause PVB film to produce extrusion deformation, so that the yield is improved, keep vacuumizing in specific temperature and pressure stage, disconnect vacuumizing after reaching temperature, until the autoclave program is completed, unexpected technical effects are achieved.

Description

Technical Field

[0001] This invention relates to the field of building-integrated photovoltaics (BIPV), specifically to a photovoltaic laminated glass for buildings, its preparation method, and its application. Background Technology

[0002] BIPV, or Building Integrated Photovoltaics, is a technology that integrates solar power generation (photovoltaic) products into buildings. BIPV photovoltaic modules appear as a form of building material, with architectural photovoltaic laminated glass being the most important component.

[0003] The autoclave method is one of the main processes for manufacturing architectural photovoltaic laminated glass. The specific operation involves placing the semi-finished photovoltaic laminated glass, after lamination, into a vacuum bag, and then steaming it in an autoclave. During the steaming process, a vacuum is maintained, typically requiring a vacuum level of -0.06 MPa. However, the autoclave method for manufacturing architectural photovoltaic laminated glass is prone to cracking and has a low yield rate.

[0004] The specific reasons are as follows:

[0005] Depending on the installation requirements, photovoltaic laminated glass junction boxes can be installed in two ways: back-mounted junction boxes and side-mounted junction boxes. Back-mounted junction boxes require drilling holes in the back glass panel, with copper strips leading out from these holes before the junction box is installed.

[0006] After the semi-finished photovoltaic laminated glass is placed into a vacuum bag and vacuumed, the state of the laminated glass is as follows: Figure 1 As shown, positions ① and ② are cavities formed by the height difference between the vacuum bag and the laminated glass, and position ③ is a cavity formed by drilling a hole in the back glass. Extremely high negative pressure is created in these cavities. At high temperatures, air is removed from positions ① and ②, causing the PVB film to flow into the cavities. This results in a thinning of the PVB film at the edges. Because the solar cell has low strength and the back glass has high strength, the solar cell is prone to deformation and cracking. At position ③, the removal of air creates negative pressure that causes the solar cell to deform into the cavity, which can easily lead to cracking.

[0007] Therefore, the development of a photovoltaic laminated glass for building and its preparation method is of great significance, as it can reduce the glass breakage rate and ensure a high yield and production efficiency. Summary of the Invention

[0008] The purpose of this invention is to address the problems of easy glass cracking and low yield in the preparation of architectural photovoltaic laminated glass using the existing high-pressure autoclave method, and to provide architectural photovoltaic laminated glass and its preparation method. This preparation method is simple to operate, has a stable process, can effectively reduce the glass cracking rate, ensure a high yield and production efficiency, and is easy to promote and apply.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A type of photovoltaic laminated glass for building applications, comprising, from bottom to top, thin-film photovoltaic glass, conductive adhesive tape layer, tin-plated copper strip, PVB film, and backsheet glass, wherein the backsheet glass has a through hole and also includes a cover; the tin-plated copper strip is divided into two sections, one end of which pierces through the PVB film, extends out from the through hole, and is bent and attached to the surface of the backsheet glass; the cover is filled and secured within the through hole.

[0011] The photovoltaic laminated glass for building is prepared by the following high-pressure autoclave steam pressing method;

[0012] Step S1: Place the assembled semi-finished photovoltaic laminated glass into a vacuum bag and evacuate it, then place it into an autoclave; within 20 to 40 minutes, raise the temperature to 70±5℃ and the pressure to 0.5 to 0.7 MPa; during this process, keep the vacuum bag evacuated, with a vacuum degree ≤-0.08 MPa.

[0013] Step S2: Maintain the pressure at 70±5℃ and 0.5~0.7Mpa in the autoclave for 15~25 minutes. During this process, keep the vacuum bag evacuated and the vacuum degree ≤-0.08MPa.

[0014] Step S3: Continue to increase the temperature and pressure, and maintain the vacuum. The vacuum degree should be ≤-0.08MPa. When the temperature rises to 105±5℃ and the pressure rises to 0.9~1.1MPa, turn off the vacuum and set the time to 20~40 minutes.

[0015] Step S4: Continue heating to 133±3℃, pressurizing to 1.2±0.05MPa, and setting the time to 20-40 minutes;

[0016] Step S5: Maintain the temperature and pressure at 133±3℃ and 1.2±0.05MPa for 60 to 90 minutes.

[0017] Step S6: Cool down and maintain pressure. Reduce the temperature to 40±5℃ and the pressure to ≥0.8MPa. Set the time to 60~90 minutes.

[0018] Step S7: Depressurize and exhaust the gas to complete the autoclave steaming process. Remove the vacuum bag to obtain photovoltaic laminated glass for building applications.

[0019] The architectural photovoltaic laminated glass provided in this application, through structural improvements and adjustments to the process and parameters of the autoclave steam pressing method, achieves a 0% cracking defect rate and ensures complete removal of air bubbles. Specifically, structurally, the cover is filled and secured within the through-hole, preventing negative pressure during subsequent vacuuming and avoiding the pressure that causes the solar cells to deform into the cavity, thus preventing cell cracking. In terms of process, traditional steam pressing technology maintains a vacuum state under high temperature conditions. However, the steam pressing process of this application first controls the temperature at approximately 70°C in two steps for slow vacuuming, effectively removing air bubbles from the laminated glass. Then, under vacuum conditions, the temperature is raised to approximately 105°C, and the vacuum is closed. This effectively prevents the PVB film from flowing into the cavity during vacuuming, which would cause the edge PVB film to thin and crack. Afterwards, high-temperature treatment is carried out with the vacuum shut off, which can increase the coupling effect between PVB and glass, improve adhesion, and prevent the PVB film from being squeezed and deformed, thus improving the yield rate. The vacuum is maintained during specific heating and pressurization stages, and then the vacuum is turned off after the temperature is reached until the autoclave program is completed. Unexpected technical effects have been achieved, making it easy to promote and apply.

[0020] Furthermore, PET tape is used to secure the tin-plated copper strip to the surface of the back glass. Using PET tape to secure the cover and the tin-plated copper strip prevents the cover from shifting or falling off during subsequent operations, and also prevents the tin-plated copper strip from being snagged or broken during subsequent operations.

[0021] Furthermore, before the assembled semi-finished photovoltaic laminated glass is placed into a vacuum bag and vacuumed, it undergoes a low-temperature pre-compression treatment. This low-temperature pre-compression treatment can prevent the glass from sliding and causing overlap during vacuum bag installation.

[0022] Furthermore, a front panel glass can be laid under the thin-film battery to form a triple-glass laminated glass, protecting the thin-film battery cells between the front and back panels, thereby improving the strength of the photovoltaic laminated glass.

[0023] Furthermore, the through hole is a circular hole; the cover is a circular structural component.

[0024] Furthermore, the thin-film photovoltaic glass is cadmium telluride thin-film power generation glass.

[0025] Furthermore, the thickness of the cover is less than or equal to the thickness of the back glass.

[0026] Furthermore, the outer diameter of the cover is smaller than the inner diameter of the through hole in the back glass, by 2-4 mm. Generally, the circular glass sheet can be made from the glass sheet left after drilling the back glass, thus reducing production steps and improving production efficiency.

[0027] Furthermore, a PVB film is wrapped around the outer wall of the cover. To reduce the gap between the circular glass sheet and the edge of the backplate glass hole, a 0.38mm or 0.76mm thick PVB film can be wrapped around the circular glass sheet beforehand. Finally, PET insulating tape is used to fix the circular glass sheet. In the final product, the circular glass sheet and the photovoltaic laminated glass are integrated into one piece.

[0028] Furthermore, the cover can be a glass structure, a polytetrafluoroethylene structure, a metal structure, or a wooden structure.

[0029] Another object of the present invention is to provide a method for preparing the above-mentioned photovoltaic laminated glass for building.

[0030] The above-mentioned method for preparing photovoltaic laminated glass for building applications includes the following steps:

[0031] Step 1: Place the thin-film photovoltaic glass flat on the worktable, and then apply the conductive film and tin-plated copper strip in sequence;

[0032] Step 2: Lay the tin-plated copper strip over the PVB film on the thin-film photovoltaic glass; mark the positions of the through holes to be contacted on the PVB film, and pierce the tin-plated copper strip through the PVB film according to the marked positions;

[0033] Step 3: Attach the backplate glass to the top of the PVB film, and bend and attach the tin-plated copper strip from the through hole to the surface of the backplate glass; then fill the through hole with the cover to obtain a semi-finished photovoltaic laminated glass.

[0034] Step 4: The semi-finished photovoltaic laminated glass obtained in Step 3 is subjected to autoclave steam treatment to obtain photovoltaic laminated glass for building use.

[0035] This application improves the preparation method of photovoltaic laminated glass for building applications. The preparation method is simple to operate, has a stable process, can effectively reduce the glass breakage rate, ensure a high yield and production efficiency, and is easy to promote and apply.

[0036] Furthermore, the specific autoclaving process includes the following steps:

[0037] Step 41: Within 20 to 40 minutes, raise the temperature to 70±5℃ and the pressure to 0.5 to 0.7 MPa; during this process, keep the vacuum bag under vacuum, with a vacuum degree ≤ -0.08 MPa;

[0038] Step 42: At a temperature of 70±5℃ and a pressure of 0.5~0.7Mpa in the autoclave, maintain the pressure for 20±5 minutes. During this process, keep the vacuum bag evacuated and the vacuum degree ≤-0.08MPa.

[0039] Step 43: Continue to increase the temperature and pressure, and maintain the vacuum level ≤ -0.08MPa. When the temperature rises to 105±5℃ and the pressure rises to 0.9~1.1MPa, turn off the vacuum and set the time to 20~40 minutes.

[0040] Step 44: Continue heating to 133±3℃, pressurizing to 1.2±0.05MPa, and setting the time to 20-40 minutes;

[0041] Step 45: Maintain the temperature and pressure at 133±3℃ and 1.2±0.05MPa for 60 to 90 minutes.

[0042] Step 46: Cool down and maintain pressure. Reduce the temperature to 40±5℃ and the pressure to ≥0.8MPa. Set the time to 60-90 minutes.

[0043] Step 47: Release the pressure and complete the autoclave steaming process.

[0044] Another objective of this application is to provide a photovoltaic laminated insulated glass for building applications.

[0045] A photovoltaic laminated insulated glass for building use, comprising the aforementioned photovoltaic laminated glass for building use.

[0046] Another objective of this application is to provide the application of the aforementioned photovoltaic laminated glass for building.

[0047] The above-mentioned applications of photovoltaic laminated glass for buildings in building roofs and curtain walls.

[0048] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0049] 1. The architectural photovoltaic laminated glass provided in this application, through structural improvements and adjustments to the process and parameters of the autoclave steam pressing method, achieves a 0% cracking defect rate for the architectural photovoltaic laminated glass product, and all air bubbles are eliminated. Specifically, structurally, the cover is filled and secured within the through hole, preventing negative pressure from being generated in the through hole during subsequent vacuuming, thus avoiding the phenomenon of air bubble cracking caused by the pressure of the solar cell deforming into the cavity due to negative pressure. In terms of process, traditional steam pressing technology maintains a vacuum state under high temperature conditions, while the steam pressing process of this application first controls the temperature at around 70°C in two steps for slow vacuuming, achieving a good air bubble removal effect in the laminated glass. Then, under vacuum conditions, the temperature is raised to around 105°C and the vacuum is turned off, effectively preventing the PVB film from flowing into the cavity during vacuuming, which would cause the edge PVB film to become thinner and cause cracking. Afterwards, high-temperature treatment is carried out with the vacuum shut off, which can increase the coupling effect between PVB and glass, improve adhesion, and prevent the PVB film from being squeezed and deformed, thus improving the yield rate. The vacuum is maintained during specific heating and pressurization stages, and then the vacuum is turned off after the temperature is reached until the autoclave program is completed. Unexpected technical effects have been achieved, making it easy to promote and apply.

[0050] 2. This application improves the preparation method of photovoltaic laminated glass for building applications. The preparation method is simple to operate, has a stable process, can effectively reduce the glass breakage rate, ensure a high yield and production efficiency, and is easy to promote and apply. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the structure of a pre-existing semi-finished photovoltaic laminated glass after it has been placed in a vacuum bag and evacuated.

[0052] Figure 2 This is a top view of the photovoltaic laminated glass for building applications provided in this application.

[0053] Figure 3 This is a side view diagram of the photovoltaic laminated glass for building applications provided in this application.

[0054] Icons: 1-Thin-film photovoltaic glass; 2-Conductive tape layer; 3-Tin-plated copper strip; 4-PVB film; 5-Back panel glass; 51-Through hole; 6-Cover body. Detailed Implementation

[0055] The present invention will now be described in detail with reference to the accompanying drawings.

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0057] Example 1

[0058] like Figure 1 and Figure 2 As shown, Embodiment 1 provides a photovoltaic laminated glass for building applications. Specifically, from bottom to top, it includes a thin-film photovoltaic glass 1, a conductive tape layer 2, a tin-plated copper strip 3, a PVB film 4, and a backsheet glass 5. The backsheet glass 5 is provided with a through hole 51 and also includes a cover 6. The tin-plated copper strip 3 is divided into two sections. One end of each section pierces through the PVB film 4, extends out from the through hole 51, and is bent and attached to the surface of the backsheet glass 5. The cover 6 is filled and secured in the through hole 51.

[0059] Specifically, further, PET tape is used to fix the tin-plated copper strip 3 to the surface of the back glass 5. Using PET tape to fix the cover and the tin-plated copper strip prevents the cover from shifting or falling off during subsequent operations, and also prevents the tin-plated copper strip from being snagged during subsequent operations.

[0060] Specifically, the thin-film photovoltaic glass 1 is cadmium telluride thin-film photovoltaic glass. The thickness of the cover 6 is less than or equal to the thickness of the backplate glass 5.

[0061] Specifically, the outer diameter of the cover 6 is smaller than the inner diameter of the through hole 51 in the back glass 5, by 2-4 mm. Generally, the circular glass sheet can be made from the glass sheet left after drilling the back glass, thus reducing production steps and improving production efficiency.

[0062] Specifically, a PVB film is wrapped around the outer wall of the cover 6. To reduce the gap between the circular glass sheet and the edge of the backplate glass hole, a 0.38mm or 0.76mm thick PVB film can be wrapped around the circular glass sheet beforehand. Finally, PET insulating tape is used to fix the circular glass sheet. In the final product, the circular glass sheet and the photovoltaic laminated glass are integrated into one piece.

[0063] Specifically, the cover 6 is a glass structure, a polytetrafluoroethylene structure, a metal structure, or a wooden structure.

[0064] Example 2

[0065] Example 2 provides the installation and preparation method of the photovoltaic laminated glass for building applications in Example 1:

[0066] Step 1: Place the thin-film photovoltaic glass 1 flat on the worktable, and then apply the conductive film and tin-plated copper strip 3 in sequence;

[0067] Step 2: Cover the tin-plated copper strip 3 with PVB film 4 and lay it on the thin-film photovoltaic glass 1; mark the position of the through hole 51 to be contacted on the PVB film 4, and pierce the tin-plated copper strip 3 through the PVB film 4 according to the marked position.

[0068] Step 3: The backplate glass 5 is attached to the top of the PVB film 4, and the tin-plated copper strip 3 is led out from the through hole 51 and bent to attach to the surface of the backplate glass 5; then the cover 6 is filled into the through hole 51 to obtain a semi-finished photovoltaic laminated glass.

[0069] Step 4: The semi-finished photovoltaic laminated glass obtained in Step 3 is subjected to autoclave steam treatment to obtain photovoltaic laminated glass for building use.

[0070] The specific autoclaving process includes the following steps:

[0071] The first stage involves raising the temperature from room temperature to 70℃ and the pressure from 0 to 0.5MPa over 35 minutes, maintaining a vacuum bag with a vacuum level ≤ -0.08MPa throughout this process. The second stage involves maintaining the temperature and pressure at 70℃ and 0.5MPa for 15 minutes, again with a vacuum bag maintained at a vacuum level ≤ -0.08MPa. The third stage involves continuing to raise the temperature and pressure while maintaining a vacuum level ≤ -0.08MPa. After 25 minutes, the temperature reaches 100℃ and the pressure reaches 0.9MPa, at which point the vacuum is shut off. The fourth stage involves further raising the temperature to 133℃ and the pressure to 1.2MPa over 30 minutes. The fifth stage involves maintaining the temperature and pressure at 133℃ and 1.2MPa for 60 minutes. The sixth stage involves lowering the temperature from 133℃ to 40℃ within 60 minutes, while maintaining the pressure above 0.8MPa. The seventh stage involves releasing the pressure and depressurizing, reducing the pressure to 0.

[0072] Example 3

[0073] Example 3 provides the installation and preparation method of the photovoltaic laminated glass for buildings in Example 1:

[0074] Step 1: Place the thin-film photovoltaic glass 1 flat on the worktable, and then apply the conductive film and tin-plated copper strip 3 in sequence;

[0075] Step 2: Cover the tin-plated copper strip 3 with PVB film 4 and lay it on the thin-film photovoltaic glass 1; mark the position of the through hole 51 to be contacted on the PVB film 4, and pierce the tin-plated copper strip 3 through the PVB film 4 according to the marked position.

[0076] Step 3: The backplate glass 5 is attached to the top of the PVB film 4, and the tin-plated copper strip 3 is led out from the through hole 51 and bent to attach to the surface of the backplate glass 5; then the cover 6 is filled into the through hole 51 to obtain a semi-finished photovoltaic laminated glass.

[0077] Step 4: The semi-finished photovoltaic laminated glass obtained in Step 3 is subjected to autoclave steam treatment to obtain photovoltaic laminated glass for building use.

[0078] The specific autoclaving process includes the following steps:

[0079] The first stage involves raising the temperature from room temperature to 65℃ and the pressure from 0 to 0.6MPa over 20 minutes, maintaining a vacuum bag with a vacuum level ≤ -0.08MPa throughout this process. The second stage involves maintaining the temperature and pressure at 65℃ and 0.6MPa for 20 minutes, again with the vacuum bag maintained at a vacuum level ≤ -0.08MPa. The third stage involves continuing to raise the temperature and pressure while maintaining a vacuum level ≤ -0.08MPa. After 20 minutes, the temperature reaches 105℃ and the pressure reaches 1MPa, at which point the vacuum is shut off. The fourth stage involves further raising the temperature to 130℃ and the pressure to 1.15MPa over 20 minutes. The fifth stage involves maintaining the temperature and pressure at 130℃ and 1.15MPa for 80 minutes. The sixth stage involves lowering the temperature from 130℃ to 35℃ over 90 minutes, while maintaining the pressure above 0.8MPa. The seventh stage involves releasing the pressure and depressurizing, reducing the pressure to 0.

[0080] Example 4

[0081] Example 4 provides the installation and preparation method of the photovoltaic laminated glass for buildings in Example 1:

[0082] Step 1: Place the thin-film photovoltaic glass 1 flat on the worktable, and then apply the conductive film and tin-plated copper strip 3 in sequence;

[0083] Step 2: Cover the tin-plated copper strip 3 with PVB film 4 and lay it on the thin-film photovoltaic glass 1; mark the position of the through hole 51 to be contacted on the PVB film 4, and pierce the tin-plated copper strip 3 through the PVB film 4 according to the marked position.

[0084] Step 3: The backplate glass 5 is attached to the top of the PVB film 4, and the tin-plated copper strip 3 is led out from the through hole 51 and bent to attach to the surface of the backplate glass 5; then the cover 6 is filled into the through hole 51 to obtain a semi-finished photovoltaic laminated glass.

[0085] Step 4: The semi-finished photovoltaic laminated glass obtained in Step 3 is subjected to autoclave steam treatment to obtain photovoltaic laminated glass for building use.

[0086] The specific autoclaving process includes the following steps:

[0087] The first stage involves raising the temperature from room temperature to 75℃ and the pressure from 0 to 0.7MPa over 40 minutes, maintaining a vacuum bag with a vacuum level ≤ -0.08MPa throughout this process. The second stage involves maintaining the temperature and pressure at 75℃ and 0.7MPa for 25 minutes, again with a vacuum bag maintained at a vacuum level ≤ -0.08MPa. The third stage involves further increasing the temperature and pressure while maintaining a vacuum level ≤ -0.08MPa. After 40 minutes, the temperature reaches 110℃ and the pressure reaches 1.1MPa, at which point the vacuum is shut off. The fourth stage involves further increasing the temperature to 136℃ and the pressure to 1.25MPa over 40 minutes. The fifth stage involves maintaining the temperature and pressure at 136℃ and 1.25MPa for 90 minutes. The sixth stage involves reducing the temperature from 136℃ to 45℃ over 80 minutes, while maintaining the pressure above 0.8MPa. The seventh stage involves releasing the pressure and depressurizing, reducing the pressure to 0.

[0088] Comparative Example 1

[0089] Compared to Example 2, Comparative Example 1 uses existing sandwich technology. The holes in the photovoltaic sandwich glass backsheet are not filled using the cover 6. The autoclave processing parameters are as follows: First stage: temperature rises from room temperature to 133°C, pressure rises from 0 to 1.2 MPa, time 90 minutes; Second stage: temperature 133°C, pressure 1.2 MPa, held at temperature and pressure for 60 minutes; Third stage: temperature drops from 133°C to below 40°C, pressure maintained above 0.8 MPa; Fourth stage: venting and depressurization, pressure drops to 0. From the beginning of the first stage to the end of the third stage, vacuum is maintained at a pressure of -0.08 MPa ± 0.01 MPa; Fourth stage: vacuum is shut off.

[0090] Comparative Example 2

[0091] Compared to Example 2, Comparative Example 2 only changed the autoclave processing parameters and filled the through hole 51 with a cover 6. The autoclave processing parameters adopted the same process as Comparative Example 1.

[0092] Comparative Example 3

[0093] Compared to Example 2, in Comparative Example 3, the holes in the backsheet of the photovoltaic laminated glass were not filled using the cover 6, and the autoclave processing parameters were exactly the same as in Example 2.

[0094] Comparative Example 4

[0095] Comparative Example 4 differs from Example 2 only in the autoclave processing parameters; the through hole 51 was filled with a cover 6. Autoclave parameters: First stage: temperature increased from room temperature to 50°C, pressure increased from 0 to 0.2 MPa, time 20 minutes; Second stage: temperature 50°C, pressure 0.2 MPa, held for 15 minutes; Third stage: continued heating and pressurization, temperature increased to 133°C, pressure increased to 1.2 MPa, time 70 minutes; Fourth stage: temperature 133°C, pressure 1.2 MPa, held for 60 minutes; Fifth stage: temperature decreased from 133°C to below 40°C, pressure maintained above 0.8 MPa; Sixth stage: venting and depressurization, pressure reduced to 0. From the first stage to the end of the fifth stage, a vacuum was maintained at a pressure of -0.08 MPa ± 0.01 MPa; in the sixth stage, the vacuum was shut off.

[0096] Comparative Example 5

[0097] Comparative Example 5 differs from Example 2 only in the autoclave processing parameters; the through hole 51 was filled with a cover 6. Autoclave parameters: First stage: temperature increased from room temperature to 70°C, pressure increased from 0 to 0.5 MPa, time 35 minutes; Second stage: temperature 70°C, pressure 0.5 MPa, held for 15 minutes; Third stage: continued heating and pressurization, temperature increased to 133°C, pressure increased to 1.2 MPa, time 55 minutes; Fourth stage: temperature 133°C, pressure 1.2 MPa, held for 60 minutes; Fifth stage: temperature decreased from 133°C to below 40°C, pressure maintained above 0.8 MPa; Sixth stage: venting and depressurization, pressure reduced to 0. From the first stage to the end of the fifth stage, vacuum was maintained at a pressure of -0.08 MPa ± 0.01 MPa; Sixth stage: vacuum was shut off.

[0098] Comparative Example 6

[0099] Comparative Example 6 differs from Example 2 only in the autoclave processing parameters, with the through hole 51 filled with the cover 6. The backplate glass 5 is also filled. Autoclave parameters are as follows: First stage: temperature rises from room temperature to 90°C, pressure rises from 0 to 0.8 MPa, time 55 minutes; Second stage: temperature 90°C, pressure 0.8 MPa, held for 15 minutes; Third stage: continued heating and pressurization, temperature rises to 133°C, pressure rises to 1.2 MPa, time 35 minutes; Fourth stage: temperature 133°C, pressure 1.2 MPa, held for 60 minutes; Fifth stage: temperature drops from 133°C to below 40°C, pressure maintained above 0.8 MPa; Sixth stage: venting and depressurization, pressure drops to 0. From the first stage to the end of the fifth stage, a vacuum is maintained at a pressure of -0.08 MPa ± 0.01 MPa; Sixth stage: vacuum is shut off.

[0100] test

[0101] Twenty samples were prepared for each of Examples 1-3 and Comparative Examples 1-6. The number of photovoltaic power generation glass pieces that were broken was recorded. Three pieces of the products with intact appearance were randomly selected for heat resistance test. The number of bubbles that appeared after the heat resistance test was recorded. The specific results are shown in Table 1.

[0102] Table 1

[0103]

[0104]

[0105] As can be seen from the test results in Table 1, Comparative Example 1, using existing sandwich technology and employing a high-temperature + vacuum process for autoclaving, failed to cover the through-hole 51, resulting in a cracking defect rate of 65% and the presence of numerous air bubbles. Comparative Example 2, based on Comparative Example 1, covered the through-hole 51, yet the cracking defect rate still reached 30%, with a significant number of air bubbles remaining. Comparative Example 3, with the through-hole 51 unfilled and the autoclave treatment using the process provided in this application, still exhibited a cracking defect rate of 10%. Comparative Examples 4-6, by altering the temperature conditions and process steps of the autoclave autoclaving, also resulted in high cracking defect rates. Therefore, it is evident that the architectural photovoltaic laminated glass provided in this application, through structural improvements and adjustments to the autoclave autoclaving process and parameters, achieves a 0% cracking defect rate and complete air bubble removal, achieving unexpected technical results.

[0106] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photovoltaic laminated glass for building applications, comprising, from bottom to top, thin-film photovoltaic glass, a conductive tape layer, a tin-plated copper strip, a PVB film, and a backsheet glass, wherein the backsheet glass has a through hole, characterized in that, It also includes a cover; the tin-plated copper strip is divided into two sections, one end of each section pierces the PVB film and is led out from the through hole and bent and attached to the surface of the back glass, and the cover is filled and secured in the through hole; The photovoltaic laminated glass for building is prepared by the following high-pressure autoclave steam pressing method; Step S1: Place the assembled semi-finished photovoltaic laminated glass into a vacuum bag and evacuate it, then place it into an autoclave; within 20 to 40 minutes, raise the temperature to 70±5℃ and the pressure to 0.5 to 0.7 MPa; during the heating and pressurization process, keep the vacuum bag evacuated, and the vacuum degree ≤-0.08 MPa; Step S2: Maintain the pressure at 70±5℃ and 0.5~0.7 MPa in the autoclave for 15~25 minutes, while keeping the vacuum bag evacuated to a vacuum degree ≤-0.08 MPa. Step S3: Continue to increase the temperature and pressure, and maintain the vacuum level ≤ -0.08 MPa. When the temperature rises to 105±5℃ and the pressure rises to 0.9~1.1 MPa, turn off the vacuum and set the time to 20~40 minutes. Step S4: Continue heating to 133±3℃, pressurizing to 1.2±0.05 MPa, and setting the time to 20-40 minutes; Step S5: Maintain the temperature and pressure at 133±3 ℃ and 1.2±0.05 MPa for 60 to 90 minutes. Step S6: Cool down and maintain pressure. Reduce the temperature to 40±5 ℃ and the pressure to ≥0.8 MPa. Set the time to 60~90 minutes. Step S7: Depressurize and exhaust the gas to complete the autoclave steaming process. Remove the vacuum bag to obtain photovoltaic laminated glass for building applications.

2. The photovoltaic laminated glass for building applications according to claim 1, characterized in that, The thin-film photovoltaic glass is cadmium telluride thin-film photovoltaic glass.

3. The photovoltaic laminated glass for building applications according to claim 1, characterized in that, The through hole is a circular hole; the cover is a circular structural component.

4. The photovoltaic laminated glass for building applications according to claim 1, characterized in that, The thickness of the cover is less than or equal to the thickness of the back glass.

5. The photovoltaic laminated glass for building applications according to claim 1, characterized in that, The outer diameter of the cover is smaller than the inner diameter of the glass through hole in the back panel by 2 to 4 mm.

6. The photovoltaic laminated glass for building applications according to claim 5, characterized in that, The outer wall of the cover is wrapped with a PVB film.

7. The photovoltaic laminated glass for building applications according to any one of claims 1-6, characterized in that, The cover is a glass structure, a polytetrafluoroethylene structure, or a metal structure.

8. A method for preparing photovoltaic laminated glass for building applications as described in any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Place the thin-film photovoltaic glass flat on the worktable, and then apply the conductive tape layer and the tin-plated copper strip in sequence; Step 2: Lay the tin-plated copper strip over the PVB film onto the thin-film photovoltaic glass; mark the positions of the through holes to be contacted on the PVB film, and pierce the tin-plated copper strip through the PVB film according to the marked positions; Step 3: Attach the backplate glass to the top of the PVB film, and bend and attach the tin-plated copper strip from the through hole to the surface of the backplate glass; then fill the through hole with the cover to obtain a semi-finished photovoltaic laminated glass. Step 4: The semi-finished photovoltaic laminated glass obtained in Step 3 is subjected to autoclave steam treatment to obtain photovoltaic laminated glass for building use.

9. A type of photovoltaic laminated insulating glass for building applications, characterized in that, Including the building photovoltaic laminated glass as described in any one of claims 1-7.

10. An application of the photovoltaic laminated glass for building as described in any one of claims 1-7 in building roofs and curtain walls.

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