Photovoltaic module

Abstract

The utility model discloses a photovoltaic assembly. The photovoltaic module comprises a glass cover plate, a front packaging adhesive film, a battery array, a rear packaging adhesive film and a glass back plate which are arranged in a stacked mode, and a plurality of parallel ceramic white strips and light reflection adhesive film layers perpendicularly crossed with the ceramic white strips are arranged on the main surface, facing the battery array, of the glass back plate at intervals; the light reflection adhesive film layer is adhered to the glass back plate; the ceramic white strips correspond to piece gaps among battery pieces of the battery array, and the light reflection adhesive film layer corresponds to string gaps among battery strings of the battery array; alternatively, the white ceramic strip corresponds to the string gap, and the light-reflecting adhesive film layer corresponds to the sheet gap. According to the photovoltaic module, the anti-bending capability of the glass back plate can be improved, and the risk that the glass back plate is bent and broken is reduced, so that the service life of the photovoltaic module is effectively prolonged.

Description

Technical Field

[0001] The utility model relates to a photovoltaic module. Background Art

[0002] At present, on the glass backplane arranged on the back of a double-glass photovoltaic module, porcelain white strips are generally printed at positions corresponding to between battery strings and positions corresponding to between solar cells. By reflecting light through the porcelain white strips, the cover plate reflects the light reflected by the porcelain white strips back onto the solar cells to improve the light utilization rate of the photovoltaic module.

[0003] However, since the porcelain white strips are generally printed on the glass backplane after the glass tempering process is completed, during the glass tempering process, the porcelain white strips will reflect heat, resulting in a rigidity gradient between the porcelain white strip area and the adjacent non-porcelain white strip area on the glass backplane. The existence of the rigidity gradient causes stress at the positions of the porcelain white strips. In particular, the cross position between the porcelain white strips corresponding to the positions between battery strings and the porcelain white strips corresponding to the positions between solar cells concentrates stresses in different directions. When the double-glass photovoltaic module is bent, the stresses in different directions at this cross position are released, resulting in the glass backplane of the double-glass photovoltaic module being broken. Summary of the Utility Model

[0004] In view of this, the utility model provides a photovoltaic module, which can improve the anti-bending ability of the glass backplane, reduce the risk of the glass backplane being broken by bending, and thus effectively improve the service life of the photovoltaic module.

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0006] The utility model provides a photovoltaic module, comprising: a glass cover plate, a front encapsulation film, a battery array, a rear encapsulation film and a glass backplane which are stacked, wherein,

[0007] On the main surface of the glass backplane facing the battery array, a plurality of parallel porcelain white strips and a light reflection adhesive film layer perpendicular to and intersecting with the porcelain white strips are arranged at intervals;

[0008] The light reflection adhesive film layer adheres to the glass backplane;

[0009] The porcelain white strips correspond to the gaps between the solar cells of the battery array, and the light reflection adhesive film layer corresponds to the gaps between the battery strings of the battery array; or, the porcelain white strips correspond to the gaps between the battery strings, and the light reflection adhesive film layer corresponds to the gaps between the solar cells.

[0010] The technical solution of the first aspect of the above utility model has the following advantages or beneficial effects:

[0011] The photovoltaic module provided by the embodiment of the present utility model can effectively reduce the stress on the glass backplane, improve the anti-bending ability of the glass backplane, and reduce the risk of bending and cracking of the glass backplane by vertically crossing the porcelain white strips and the light-reflecting adhesive film layer compared with the case where the inter-chip gap and the inter-string gap both correspond to the porcelain white strips.

[0012] In addition, the porcelain white strips and the light-reflecting adhesive film layer respectively correspond to the inter-chip gap and the inter-string gap, which can effectively improve the light utilization rate of the battery cells and thus improve the photoelectric conversion efficiency of the photovoltaic module. Description of the Drawings

[0013] Figure 1 is a schematic structural diagram of the glass backplane according to the embodiment of the present utility model;

[0014] Figure 2 is a schematic cross-sectional structural diagram of the first structure of the photovoltaic module along the extension direction of the battery string according to the embodiment of the present utility model;

[0015] Figure 3 is a schematic cross-sectional structural diagram of the second structure of the photovoltaic module along the extension direction of the battery string according to the embodiment of the present utility model;

[0016] Figure 4 is along the Figure 1 shown sectional line A-A of the glass backplane schematic cross-sectional structure corresponding to the second structure of the photovoltaic module according to the embodiment of the present utility model;

[0017] Figure 5 is a schematic cross-sectional structural diagram of the photovoltaic module in the vertical direction perpendicular to the extension direction of the battery string according to the embodiment of the present utility model;

[0018] Figure 6 is a schematic main process diagram of the method for manufacturing the photovoltaic module according to the embodiment of the present utility model;

[0019] Figure 7 is a schematic diagram of the structural change corresponding to step S601 according to the embodiment of the present utility model;

[0020] Figure 8 is a schematic cross-sectional structural diagram of the light-reflecting adhesive film layer according to the embodiment of the present utility model.

[0021] The reference numerals are as follows:

[0022] 10 - glass cover plate; 20 - front encapsulation film; 30 - battery array; 40 - rear encapsulation film; 50 - glass backplane; 51 - porcelain white strip; 52 - light-reflecting adhesive film layer; 521 - adhesive layer; 522 - substrate layer; 523 - reflective layer. Detailed Embodiments

[0023] The photovoltaic module involved in the embodiments of the present utility model generally refers to a double-glass photovoltaic module.

[0024] By improving the structure of the photovoltaic module, the embodiments of the present utility model combine the porcelain white strips with the light-reflecting adhesive film layer, which can not only improve the light utilization rate and photoelectric conversion efficiency of the photovoltaic module, but also reduce the risk of the backplane of the photovoltaic module being broken.

[0025] Among them, Figure 1 is a schematic structural diagram of the glass backplane provided by the embodiments of the present utility model; Figure 2 and Figure 3 are schematic cross-sectional structural diagrams of two photovoltaic modules provided by the embodiments of the present utility model; Figure 4 is a schematic diagram showing the relative relationship between the porcelain white strip and the light-reflecting adhesive film layer in a cross-sectional structure of the glass backplane shown along the cross-sectional line A-A provided by the embodiments of the present utility model; Figure 1 is a schematic diagram showing the relative relationship between the porcelain white strip and the light-reflecting adhesive film layer in a cross-sectional structure of the glass backplane shown along the cross-sectional line A-A provided by the embodiments of the present utility model; Figure 5 is a schematic cross-sectional structure diagram of the photovoltaic module in the direction perpendicular to the extending direction of the battery string provided by the embodiments of the present utility model.

[0026] The embodiments of the present utility model provide a photovoltaic module. As shown in Figure 2 , Figure 3 and Figure 5 , the photovoltaic module may include: a glass cover plate 10, a front encapsulation film 20, a battery array 30, a rear encapsulation film 40, and a glass backplane 50 which are stacked. Among them,

[0027] On the main surface of the glass backplane 50 facing the battery array 30, a plurality of parallel porcelain white strips 51 and a light-reflecting adhesive film layer 52 perpendicular to the porcelain white strips are arranged at intervals;

[0028] The light-reflecting adhesive film layer 52 adheres to the glass backplane 50;

[0029] The porcelain white strips 51 correspond to the gaps between the battery cells of the battery array 30, and the light-reflecting adhesive film layer 52 corresponds to the gaps between the battery strings of the battery array 30; or, the porcelain white strips 51 correspond to the string gaps, and the light-reflecting adhesive film layer 52 corresponds to the cell gaps.

[0030] Among them, as shown in Figure 2 , Figure 3 and Figure 5 , in the photovoltaic module, the front encapsulation film 20 and the rear encapsulation film 40 are formed as a whole to encapsulate the battery array 30 and prevent the battery array 30 from contacting the air.

[0031] Among them, the porcelain white strips 51 are formed during the tempering process of the glass backplane 50. Specifically, ordinary glass is selected, and parallel white slurries are printed at intervals (the slurry generally contains metal oxide particles with relatively good light-reflecting properties such as TiO2 , ZnO), and subject the glass plate printed with the paste to tempering treatment to cure the paste into a porcelain white strip 51.

[0032] Since the paste contains metal oxide particles with relatively good light reflection performance, during the tempering treatment of the glass plate, the paste will reflect heat, causing the temperature in the area where the paste is located to be lower, while the temperature in the area where the paste is not coated is higher. This makes the tempering performance of the area where the paste is located different from that of the area where the paste is not coated, generating a tempering gradient and causing stress in the area where the porcelain white strip is formed. In the prior art, at the intersection of the porcelain white strip corresponding to the gap between battery strings and the porcelain white strip corresponding to the gap between battery cells, tempering gradients in different directions will be generated, resulting in easy brittle cracking when the glass backplane is bent.

[0033] It can be understood that the edge of the light reflection adhesive film layer 52 overlaps with the edge part of the adjacent battery cell; the edge of the porcelain white strip 51 overlaps with the edge part of the adjacent battery cell. To reduce light loss. Further, the width of the overlapping part is 0.2 - 0.4 mm. For example, the width of the overlapping part can be 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, or 0.4 mm, etc.

[0034] Compared with the porcelain white strips corresponding to both the cell gap and the string gap in the photovoltaic module provided by the embodiment of the present invention, by vertically crossing the porcelain white strip and the light reflection adhesive film layer, it is possible to avoid the influence of tempering gradients in different directions on the glass backplane, effectively reduce the stress on the glass backplane, improve the anti-bending ability of the glass backplane, and reduce the risk of bending and cracking of the glass backplane.

[0035] In addition, the porcelain white strip and the light reflection adhesive film layer respectively correspond to the cell gap and the string gap, which can effectively improve the light utilization rate of the battery cell to improve the photoelectric conversion efficiency of the photovoltaic module.

[0036] In addition, the above-mentioned front encapsulation film 20 and rear encapsulation film 40 can directly select the encapsulation film materials used in existing photovoltaic modules, and there is no limitation on the materials used for the front encapsulation film 20 and the rear encapsulation film 40 here.

[0037] Further, as Figure 8 shown, the above-mentioned light reflection adhesive film layer 52 may include: a bonding layer 521, a substrate layer 522, and a reflection layer 523 stacked in sequence, wherein the bonding layer 521 is bonded to the glass backplane 50. This structure can achieve the purpose of reflecting light to the battery cell.

[0038] Among them, the light-reflecting adhesive film layer 52 can be a specular reflection film or a diffuse reflection film. For the specular reflection film, the reflected light directly reaches the glass cover plate and is reflected to the battery cell through the glass cover plate. Generally, the production process of the specular reflection film is relatively strict and the cost is relatively high. For the diffuse reflection film, the reflected light may be reflected multiple times on the diffuse reflection film before reaching the glass cover plate and then reflected to the battery cell through the glass cover plate. Therefore, compared with the specular reflection film, the light attenuation through the diffuse reflection film is relatively serious and the performance of the reflected light is poor. However, the diffuse reflection film has relatively low process requirements and low cost.

[0039] Since the current chip gap has become smaller and smaller (usually less than 1.8 mm), the light passing through the chip gap is relatively less. Based on the differences between the specular reflection film and the diffuse reflection film, through cost and benefit accounting of setting the specular reflection film and the diffuse reflection film, it is found that the cost of choosing the specular reflection film does not match the electrical energy generated by this part of the reflected light, and the benefit of the electrical energy generated by this part of the reflected light cannot cover the cost of the specular reflection film. While the cost of choosing the diffuse reflection film and the benefit of the electrical energy generated by the reflected light based on the diffuse reflection film can cover the cost of the specular reflection film. Therefore, for the structure of the light-reflecting adhesive film layer 52 corresponding to the chip gap, the light-reflecting adhesive film layer 52 is a diffuse reflection film.

[0040] Among them, the diffuse reflection film includes a film layer formed by any one or more of the following materials:

[0041] White EVA (ethylene-vinyl acetate copolymer), white POE (a copolymer of ethylene and butene), white EPE (a three-layer co-extruded film of transparent EVA-white POE-transparent EVA or an EVA-PET-EVA three-layer backplane film), white EE (a two-layer co-extruded film of white EVA-transparent EVA), white CPE (a Fluororesin Coating-PET-EVA three-layer backplane film), and white PE (a PET-EVA two-layer backplane film), etc.

[0042] In addition, for the structure of the light-reflecting adhesive film layer 52 corresponding to the string gap, the light-reflecting adhesive film layer 52 is a specular reflection film. The existing specular reflection film can be directly selected for the specular reflection film, and the materials used for the specular reflection film are not restricted here.

[0043] Specifically, for the structure of the light-reflecting adhesive film layer 52 corresponding to the string gap, it can be as Figure 1 shown, and the Figure 1 exemplarily gives a schematic diagram of the relative relationship between the porcelain white strip 51 corresponding to the chip gap and the light-reflecting adhesive film layer 52 corresponding to the string gap on the glass backplane 50. From Figure 1It can be seen that the porcelain white strip 51 extends in one direction. The porcelain white strip 51 extending in one direction will generate stress on the glass backplane 50 in the extending direction of the porcelain white strip 51. The light-reflecting adhesive film layer 52 intersects the porcelain white strip 51 perpendicularly. Compared with the structure with porcelain white strips between cells, the bidirectional stress intersection is optimized into unidirectional stress, improving the glass stiffness.

[0044] Furthermore, there are two structures for the glass backplane 50 provided in the embodiments of the present invention.

[0045] Specifically, the first structure of the glass backplane 50: The main surface of the glass backplane 50 corresponding to the battery array 30 is a plane, and the porcelain white strip 51 and the light-reflecting adhesive film layer 52 are on this plane.

[0046] The second structure of the glass backplane 50: As Figure 3 and Figure 4 shown, the main surface of the glass backplane 50 corresponding to the battery array 30 is a regular concave-convex structure. Among them, the porcelain white strip 51 is located in the convex area of the concave-convex structure. That is: The thickness of the area corresponding to the porcelain white strip 51 is greater than the thickness of other areas outside the porcelain white strip. Through this structural design, during the tempering process of the glass, heat can enter from the groove part into the convex part of the glass below the printed porcelain white strip 51, reducing the gradient difference of the tempering gradient and even avoiding the occurrence of the tempering gradient, so as to further improve the anti-bending ability of the glass backplane 50. For this structure, the set light-reflecting adhesive film layer 52 is bonded to the convex part of the glass. After lamination, part of the adhesive film of the back encapsulation adhesive film 40 enters into the groove of the concave-convex structure on the main surface of the glass backplane 50. That is: A part of the back encapsulation adhesive film 40 fills between the light-reflecting adhesive film layer 52 and other areas. Ensure the stability of the light-reflecting adhesive film layer 52, and at the same time improve the bonding force between the glass backplane 50 and the back encapsulation adhesive film 40, so that during the impact process of the photovoltaic module, the back encapsulation adhesive film 40 can provide better buffering for the glass backplane 50.

[0047] For the second structure of the above glass backplane 50, the thickness of the area corresponding to the porcelain white strip (such as Figure 3 and Figure 4 shown as H1) and the thickness of other areas (such as Figure 3 and Figure 4The difference between the thickness of the area corresponding to the porcelain white strip and other areas is 0.5 to 2 mm. For example, the difference can be 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.8 mm, or 2 mm, etc. Specifically, the size of this difference is related to the thickness H2 of other areas of the glass backplane 50. For example, if the thickness H2 of this other area is 0.5 mm, then this difference is generally between 0.5 and 2 mm; if the thickness H2 of other areas is 4 mm, then this difference is generally between 0.5 and 1 mm.

[0048] In addition, through the design of the second structure of the above-mentioned glass backplane 50, the paste of the porcelain white strip 51 can be directly printed on the convex area, avoiding the printing alignment process, ensuring the process operation accuracy, and effectively improving the process efficiency of printing the porcelain white strip 51.

[0049] Furthermore, an embodiment of the present invention provides a preparation method for a photovoltaic module according to any of the above embodiments. Specifically, as Figure 6 shown, the preparation method of the photovoltaic module may include the following steps:

[0050] Step S601: Stack and lay the glass cover plate 10, the front encapsulation film 20, the battery array 30, the rear encapsulation film 40, and the glass backplane 50 in sequence from bottom to top to form a stacked structure. Among them, on the main surface of the glass backplane 50 facing the battery array 30, a plurality of parallel porcelain white strips 51 and a light-reflecting adhesive film layer 52 perpendicular to and intersecting the porcelain white strips are arranged at intervals. The porcelain white strips 51 correspond to the gaps between the battery cells of the battery array 30, and the light-reflecting adhesive film layer 52 corresponds to the gaps between the battery strings of the battery array 30; or, the porcelain white strips 51 correspond to the string gaps, and the light-reflecting adhesive film layer 52 corresponds to the cell gaps;

[0051] Among them, the structural change corresponding to this step S601 can be as Figure 7 shown.

[0052] It should be noted that the process of printing the paste of the porcelain white strip on the glass backplane 50, the tempering process, and the process of pasting the light-reflecting adhesive film layer 52 can be completed synchronously with this step S601, or can be completed before step S601.

[0053] That is to say, before step S601 in this preparation method or before laying the glass backplane 50 in step S601, it may also include: providing a glass backplane 50, on one main surface of which a plurality of parallel porcelain white strips 51 are arranged at intervals; and pasting a light-reflecting adhesive film layer 52 perpendicular to and intersecting the porcelain white strips 51 on the main surface of the glass backplane 50 with the porcelain white strips 51 according to a set spacing. Specifically, for Figure 4For the structure of the glass backplane 50 shown, the light-reflecting adhesive film layer 52 pasted perpendicular to the porcelain white strips 51 is essentially to paste the light-reflecting adhesive film layer 52 on the raised part of the main surface of the glass backplane 50, so that there is a gap between the sunken part and the light-reflecting adhesive film layer 52. During the subsequent lamination process, the post-encapsulation adhesive film 40 flows and fills the sunken part, achieving the purpose of better stabilizing the light-reflecting adhesive film layer 52 and being able to improve the bonding ability between the glass backplane 50 and the post-encapsulation adhesive film 40.

[0054] In addition, printing multiple spaced and parallel porcelain white strips 51 and the tempering process can also be part of the preparation method of the photovoltaic module.

[0055] Step S602: Laminate the stacked structure.

[0056] The entire preparation method does not need to change the existing lamination process and lamination process of the photovoltaic module, making the preparation method industrially realizable.

[0057] In the photovoltaic module prepared by the preparation method provided by the embodiment of the present invention, compared with the porcelain white strips corresponding to both the cell gap and the string gap, by arranging the porcelain white strips and the light-reflecting adhesive film layer perpendicular to each other, the stress on the glass backplane can be effectively reduced, the anti-bending ability of the glass backplane can be improved, the risk of the glass backplane being bent and broken can be reduced, and thus the lifespan of the photovoltaic module can be improved.

[0058] In addition, the porcelain white strips and the light-reflecting adhesive film layer respectively corresponding to the cell gap and the string gap can effectively improve the light utilization rate of the solar cells, so as to improve the photoelectric conversion efficiency of the photovoltaic module.

[0059] The following uses several embodiments to detail the structure of the photovoltaic module provided by the embodiment of the present invention.

[0060] Embodiment 1:

[0061] On the glass backplane, porcelain white strips are printed corresponding to the cell gaps between the solar cells, and a specular reflection film is pasted corresponding to the string gaps between the cell strings, which improves the glass strength and ensures the cost performance of the pasted specular reflection film.

[0062] Embodiment 2:

[0063] On the glass backplane, porcelain white strips are printed corresponding to the string gaps between the cell strings, and a diffuse reflection film is pasted corresponding to the cell gaps between the solar cells, which improves the glass strength and ensures the cost performance of the pasted diffuse reflection film.

[0064] Embodiment 3:

[0065] Use a diffuse reflection film to replace the porcelain white strips in Embodiment 1.

[0066] Comparative example:

[0067] On the glass back panel, white porcelain strips are printed corresponding to the string gaps between battery strings and the cell gaps between battery cells.

[0068] For the above-mentioned Examples 1 to 3 and the comparative example, the anti-falling ball height (the anti-falling ball height experiment: a solid steel ball with a diameter of 38.1 mm and a mass of 227 g was used to perform free fall motion toward the glass back panel at several set heights. As the distance between the drop point of the solid steel ball and the glass back panel increases, the risk of the glass back panel breaking increases. The anti-falling ball height is the distance between the drop point of the steel ball and the glass back panel when the glass back panel breaks) and the photoelectric conversion performance of the photovoltaic modules of the same version are tested (the result of the photoelectric conversion performance is: the increase in the power of the photovoltaic modules of each embodiment compared to the comparative example), and the test results are shown in Table 1 below.

[0069]

[0070] The introduction provided in the above steps is only used to help understand the method, structure and core idea of ​​the utility model. For ordinary technicians in this technical field, the utility model can also be improved and modified without departing from the principle of the utility model, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. A photovoltaic module, characterized in that: include: A glass cover plate (10), a front encapsulation film (20), a battery array (30), a rear encapsulation film (40), and a glass back plate (50) are stacked, wherein: A plurality of parallel white porcelain strips (51) and a light-reflecting adhesive film layer (52) perpendicularly intersecting the white porcelain strips are arranged at intervals on the main surface of the glass back plate (50) facing the battery array (30); The light-reflecting adhesive film layer (52) is adhered to the glass back plate (50); The white porcelain strip (51) corresponds to the sheet gap between the battery sheets of the battery array (30), and the light reflecting adhesive film layer (52) corresponds to the string gap between the battery strings of the battery array (30); or, the white porcelain strip (51) corresponds to the string gap, and the light reflecting adhesive film layer (52) corresponds to the sheet gap.

2. The photovoltaic module according to claim 1, characterized in that: The light-reflecting adhesive film layer (52) comprises: an adhesive layer (521), a substrate layer (522) and a reflective layer (523) stacked in sequence, wherein: The bonding layer (521) is bonded to the glass back plate (50).

3. The photovoltaic module according to claim 1 or 2, characterized in that: The light reflecting adhesive film layer (52) is a specular reflecting film or a diffuse reflecting film.

4. The photovoltaic module according to claim 3, characterized in that: With respect to the structure in which the light-reflecting adhesive film layer (52) corresponds to the sheet gap, the light-reflecting adhesive film layer (52) is a diffuse reflection film; or, With respect to the structure in which the light-reflecting adhesive film layer (52) corresponds to the string gap, the light-reflecting adhesive film layer (52) is a mirror-reflecting film.

5. The photovoltaic module according to claim 1, characterized in that: With respect to the glass back plate (50), the thickness of the area corresponding to the white porcelain strip is greater than the thickness of other areas outside the white porcelain strip.

6. The photovoltaic module according to claim 5, characterized in that: The difference between the thickness of the area corresponding to the white porcelain strip and the thickness of the other areas is 0.5-2 mm.

7. The photovoltaic module according to claim 5 or 6, characterized in that: A portion of the rear packaging adhesive film (40) is filled between the light reflective adhesive film layer (52) and the other area.

8. The photovoltaic module according to any one of claims 1, 2 and 4 to 6, characterized in that: The edge of the light-reflecting adhesive film layer (52) partially overlaps with the edge of the adjacent battery cell; The edge of the white porcelain strip (51) partially overlaps with the edge of the adjacent battery cell.

9. The photovoltaic module according to claim 8, characterized in that: The width of the overlapping part is 0.2~0.4mm.

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