A photovoltaic module

Abstract

The utility model discloses a photovoltaic module, including front light cover, backboard and set up between the cell string of front light cover and backboard, the cell string is fixed on backboard, the front of cell string is opposite with front light cover and forms the set clearance, the photovoltaic module still includes the adhesive film sealing layer, and the surface of front light cover and backboard is connected through adhesive film sealing layer, the adhesive film sealing layer surrounds cell string, and with front light cover and backboard jointly form the cavity that cell string is sealed in, the cavity is set up as vacuum. The utility model can improve the efficiency of photovoltaic module.

Description

Technical Field

[0001] This utility model relates to the field of solar energy technology, specifically to a photovoltaic module. Background Technology

[0002] A photovoltaic module generally includes a front light-transmitting cover, a back sheet, and a string of cells encapsulated between the front light-transmitting cover and the back sheet. The installation of the cell string between the front light-transmitting cover and the back sheet is generally achieved by connecting the cell string to the front light-transmitting cover and the back sheet respectively through an adhesive film layer to ensure a stable installation effect.

[0003] However, the photovoltaic modules installed in the above manner use a film to encapsulate the front side. When the photovoltaic modules are in use, sunlight needs to pass through the front light-transmitting cover and the film layer between the front light-transmitting cover and the battery string before it can shine on the front side of the battery string. The light transmittance of the existing film can only reach about 90%. Therefore, such a structure will seriously affect the efficiency of the battery string in utilizing sunlight, resulting in a large power loss of the photovoltaic modules. Utility Model Content

[0004] This invention aims to address one of the technical problems in related technologies to a certain extent. To this end, this invention provides a photovoltaic module that can improve the efficiency of the battery string in utilizing sunlight and ensure a good working environment for the battery string.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A photovoltaic module includes a front light-transmitting cover, a back panel, and a battery string disposed between the front light-transmitting cover and the back panel. The battery string is fixed to the back panel, and the front surface of the battery string faces the front light-transmitting cover and forms a predetermined gap. The photovoltaic module also includes an adhesive film sealing layer, which connects the facing surfaces of the front light-transmitting cover and the back panel. The adhesive film sealing layer surrounds the battery string and, together with the front light-transmitting cover and the back panel, forms a cavity that seals the battery string. The cavity is set as a vacuum.

[0007] In this technical solution, the battery string is fixed to the backplate, and there are no obstructions between the front of the battery string and the front light-transmitting cover. When the photovoltaic module is working, sunlight can pass through the front light-transmitting cover and directly illuminate the front of the battery string, where it is absorbed to generate electricity. Compared to the existing technology where a film layer is placed between the front light-transmitting cover and the battery string, this reduces the energy loss of sunlight passing through the film layer, improves the photovoltaic module's utilization efficiency of sunlight, and thus improves the power generation efficiency of the photovoltaic module. Furthermore, this technical solution also includes a circumferential film sealing layer around the battery string. This film sealing layer prevents moisture, humidity, and external dust from entering the cavity and affecting the operation of the battery string. The film sealing layer provides a good working environment for the battery string, improving its lifespan and efficiency, and enhancing the weather resistance of the photovoltaic module when installed outdoors.

[0008] Furthermore, the photovoltaic module also includes a second adhesive film layer, through which the back side of the battery string is bonded to the surface of the backsheet. Bonding facilitates the connection between the second adhesive film layer and the backsheet.

[0009] Furthermore, the sealing film layer and the second sealing film layer are connected. Connecting the sealing film layer and the second sealing film layer as a whole can improve the overall strength of the photovoltaic module and enhance the sealing effect of the sealing film layer on the cavity.

[0010] Furthermore, the backplate has adhesive grooves formed on its surface for mounting the battery string, the adhesive grooves being opposite to the back of the battery string. The second adhesive film layer can fill the adhesive grooves to strengthen the connection between the second adhesive film layer and the backplate, thereby increasing the bonding strength between the adhesive film sealing layer and the second adhesive film layer.

[0011] Furthermore, the adhesive film sealing layer is made of butyl rubber.

[0012] Furthermore, the distance between the adhesive film sealing layer and the edge of the back plate is 0-3mm, and the width of the adhesive film sealing layer is set to 5-10mm. This ensures the reliability of the connection between the adhesive film sealing layer and the front light-transmitting cover and the back plate, improves the connection strength, and the design with a certain width also helps to form a sealed environment in the cavity.

[0013] Furthermore, the back panel is configured as a back panel glass.

[0014] Furthermore, the battery string includes crystalline silicon heterojunction solar cells.

[0015] Furthermore, the photovoltaic module includes an adsorption layer disposed in the cavity and located on the side of the battery string, the adsorption layer being used to absorb water vapor.

[0016] Furthermore, the photovoltaic module also includes a rigid support member. This rigid support member is disposed between the front light-transmitting cover and the back panel. The rigid support member rigidly supports the front light-transmitting cover and the back panel, maintaining a predetermined gap between them. This avoids the risk of damage to the battery strings caused by pressure on the photovoltaic module during use or transportation.

[0017] These features and advantages of this utility model will be disclosed in detail in the following specific embodiments and accompanying drawings. The preferred embodiments or means of this utility model will be shown in detail in conjunction with the accompanying drawings, but are not intended to limit the technical solutions of this utility model. In addition, each of these features, elements and components appearing in the following text and drawings is multiple and is labeled with different symbols or numbers for convenience, but all represent parts with the same or similar structure or function. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings:

[0019] Figure 1 This is a front cross-sectional view of a photovoltaic module according to one embodiment of the present invention;

[0020] Figure 2 This is a top cross-sectional view of a photovoltaic module according to one embodiment of the present invention;

[0021] Figure 3 This is a top cross-sectional view of a photovoltaic module according to one embodiment of the present invention;

[0022] Figure 4 This is a front cross-sectional view of a photovoltaic module according to one embodiment of the present invention;

[0023] Figure 5 This is a top cross-sectional view of a photovoltaic module according to one embodiment of the present invention.

[0024] in,

[0025] 10. Front light-transmitting cover; 20. Back panel; 30. Battery string; 40. Adhesive film sealing layer; 50. Second adhesive film layer; 60. Adsorption layer; 70. Cavity. Detailed Implementation

[0026] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described are intended to explain this utility model and should not be construed as limiting it.

[0027] The terms "an embodiment," "example," or "trademark" used in this specification refer to a particular feature, structure, or characteristic described in connection with the embodiment itself that may be included in at least one embodiment disclosed in this utility model. The phrase "in an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0028] See appendix Figure 1 , 2 4. One embodiment of this utility model discloses a photovoltaic module, including a front light-transmitting cover 10, a back plate 20, and a battery string 30 disposed between the front light-transmitting cover 10 and the back plate 20. The front side of the battery string 30 faces the front light-transmitting cover 10 and forms a set gap. The opposing surfaces of the front light-transmitting cover 10 and the back plate 20 are connected by an adhesive film sealing layer 40. The adhesive film sealing layer 40 surrounds the battery string 30 and together with the front light-transmitting cover 10 and the back plate 20 forms a cavity 70 that seals the battery string 30. The cavity 70 is set as a vacuum.

[0029] In this embodiment, when the photovoltaic module is in use, the front light-transmitting cover 10 and the back sheet 20 serve to protect the battery string 30 and improve the strength of the photovoltaic module. During operation, solar light passes through the front light-transmitting cover 10 and shines on the front of the battery string 30, and is absorbed by the battery string 30 to generate electrical energy. In actual installation, the photovoltaic module can be set as single-glass encapsulation or double-glass encapsulation. In actual installation, only the structure of the back sheet 20 needs to be changed, and there is no specific limitation.

[0030] In this invention, the back of the battery string 30 is fixed to the back plate 20, and there is no component between the front of the battery string 30 and the front light-transmitting cover 10, forming a gap. In this way, during operation, there is no obstruction between the front of the battery string 30 and the front light-transmitting cover 10. When the photovoltaic module is working, sunlight can pass through the front light-transmitting cover 10 and directly shine on the front of the battery string 30, and be absorbed by the battery string 30 to generate electricity. Compared with the structure of setting an adhesive film layer between the front light-transmitting cover 10 and the battery string 30 in the prior art, the energy loss of sunlight passing through the adhesive film layer is reduced, the utilization efficiency of sunlight by the photovoltaic module is improved, and thus the power generation efficiency of the photovoltaic module can be improved.

[0031] To prevent moisture or external impurities from affecting the performance of the battery string 30, this invention provides a sealing film layer 40 between the front light-transmitting cover 10 and the back plate 20, surrounding the battery string 30. The sealing film layer 40, together with the front light-transmitting cover 10 and the back plate 20, forms a cavity 70 that seals the battery string 30. In this way, during use, the sealing film layer 40 can prevent moisture, humidity, and external dust from entering the cavity 70 and affecting the operation of the battery string 30. The sealing film layer 40 provides a good working environment for the battery string 30, improves the lifespan and working efficiency of the battery string 30, and enhances the weather resistance of the photovoltaic module when installed outdoors.

[0032] In addition to its sealing function, the adhesive film sealing layer 40 in this invention also serves to support the front light-transmitting cover 10 and the back plate 20. The adhesive film sealing layer 40 in this embodiment can withstand a certain amount of pressure, preventing the front light-transmitting cover 10 or the back plate 20 from being compressed during transportation, installation, and use. This embodiment does not impose specific limitations on the structure of the adhesive film sealing layer 40. In actual installation, the adhesive film sealing layer 40 can be a single-layer structure or a multi-layer structure. For example, the adhesive film sealing layer 40 can be formed after the adhesive film layer has cured, or it can be a structure where a rigid support member cooperates with the adhesive film layer.

[0033] After the photovoltaic module of this invention is assembled with the front light-transmitting cover 10, the photovoltaic module, and the back sheet 20, it undergoes vacuum lamination on a laminator to create a vacuum within the cavity 70. Maintaining a vacuum in the area between the battery string 30 and the front light-transmitting cover 10 ensures the reliability of the sealed component. The vacuum environment of the cavity 70 prevents the battery string 30 from reacting with moisture or gases in the air, meeting the operational requirements of the highly sensitive battery string 30. In practical design, a vacuum detection component can be installed within the cavity 70 to promptly determine whether a vacuum environment is present.

[0034] In this embodiment, the back of the battery string 30 is bonded to the back plate 20 via a second adhesive film layer 50. This adhesive bonding method makes installation of the battery string 30 more convenient. In actual installation, the battery string 30 can be directly connected to the back plate 20 via the second adhesive film layer 50, or it can be connected via an adapter. To improve connection stability, adhesive grooves can be provided on the surfaces where the back plate 20 and / or the battery string 30 connect. When the second adhesive film layer 50 is used, the adhesive film can overflow into the adhesive grooves, improving the reliability of the connection between the battery string 30 and the back plate 20.

[0035] In addition, in specific settings, a mounting groove that matches the back dimensions of the battery string 30 can be provided on the back plate 20, and the battery string 30 can be placed in the mounting groove, which can further improve the stability of the battery string 30 installation.

[0036] In one embodiment of this utility model, the second adhesive film layer 50 is configured as an adhesive film layer, and the entire back surface of the battery string 30 is coated with the adhesive film layer. This increases the connection area between the battery string 30 and the back plate 20, thereby improving the stability of the battery string 30 installation. In actual installation, the second adhesive film layer 50 can also be configured as a ring structure and disposed between the back surface of the battery string 30 and the back plate 20, just like the adhesive film sealing layer 40. This also forms a circumferential connection for the battery string 30, which can further improve stability to a certain extent.

[0037] In one embodiment of this utility model, the top surface of the adhesive film sealing layer protrudes from the front surface of the back plate. This way, after the battery string is installed, the bottom surface of the battery string will be higher than the surface of the back plate, which facilitates installation. Moreover, it allows the front surface of the battery string to be closer to the front light-transmitting cover, reducing the situation where sunlight is blocked by the adhesive film sealing layer when it shines on the battery string.

[0038] It is conceivable that the second adhesive film layer 50 may also include multiple spaced connection points to form a multi-point connection between the battery string 30 and the backplate 20.

[0039] In one embodiment of this utility model, the adhesive film sealing layer 40 and the second adhesive film layer 50 are thermally fused together. See attached drawing. Figure 4 , 5 This is a schematic diagram showing the fusion bonding of the sealant layer 40 and the second sealant layer 50 under high temperature lamination. By setting the sealant layer 40 and the second sealant layer 50 as a single unit, the overall strength of the photovoltaic module can be improved. Moreover, after the second sealant layer 50 melts, it can fill the joint surface between the sealant layer 40 and the backsheet 20, which can improve the sealing effect of the joint and thus improve the sealing effect of the sealant layer 40 on the cavity 70.

[0040] In actual installation, the sealing layer 40 and the second film layer 50 can be made of different colloids. In one embodiment of this invention, the sealing layer 40 is made of a high water-resistant hot-melt elastic colloid. The high water-resistant hot-melt elastic colloid has a good water-resistant sealing effect, which can prevent water vapor from entering the cavity 70 from the joint between the sealing layer 40 and the front light-transmitting cover 10 and / or the back plate 20. Specifically, it can be made of butyl rubber. Butyl rubber has good air tightness, heat resistance, ozone resistance, aging resistance, chemical resistance, shock absorption, electrical insulation properties, and good resistance to sunlight and ozone, which can well adapt to the working conditions of photovoltaic modules.

[0041] To further improve the working environment of the battery string 30, in one embodiment of this invention, an adsorption layer 60 may be provided inside the cavity 70 between the adhesive film sealing layer 40 and the sidewall of the battery string 30. The adsorption layer 60 is used to absorb moisture. See attached drawing. Figure 3 Specifically, the adsorption layer 60 can be made of a hydrolyzable cross-linked material. This hydrolyzable cross-linked material can absorb moisture entering the enclosed area and undergoes a cross-linking reaction after moisture absorption, increasing the material's viscosity and density, thereby achieving a secondary encapsulation effect.

[0042] For specific installation instructions of the photovoltaic module of this utility model, please refer to the appendix. Figure 1 , 2 3. The distance between the adhesive film sealing layer 40 and the edge of the back plate 20 is 0-3mm. During the application of the adhesive film sealing layer 40, the adhesive is dispensed by controlling the adhesive application through a dispensing nozzle. A certain gap (generally 2-3mm) is maintained between the adhesive film sealing layer 40 and the edge of the back plate 20. This provides sufficient space for the subsequent high-temperature melting of the adhesive film sealing layer 40. After melting, the adhesive film sealing layer 40 can flow to the position aligned with the edges of the back plate 20 and the front light-transmitting cover 10, forming as shown in the attached figure. Figure 4 , 5 The state in.

[0043] One embodiment of this utility model limits the width of the adhesive film sealing layer 40 to 5-10 mm. By setting the lower limit of the width of the adhesive film sealing layer 40 to 5 mm, the minimum width of the adhesive film sealing layer 40 is ensured. As is well known, the wider the adhesive film sealing layer 40 is coated, the larger its contact area with the front light-transmitting cover 10 and the back plate 20 will be. This can ensure the reliability of the connection between the adhesive film sealing layer 40 and the front light-transmitting cover 10 and the back plate 20, and improve the connection strength. In addition, the design with a certain width also helps to improve the sealing effect on the cavity 70 (forming a wider surface seal).

[0044] In one embodiment of this utility model, a rigid support member can be provided between the front light-transmitting cover 10 and the back plate 20. The rigid support member is used to maintain the set gap. The rigid support member supports the front light-transmitting cover 10 and the back plate 20, which can improve the overall strength of the photovoltaic module. In addition, it can also form a relatively constant spacing for the cavity 70, avoiding the risk of damage to the battery string 30 caused by the compression of the photovoltaic module during use or transportation when only an elastic film is used.

[0045] In actual installation, the two ends of the rigid support can be fixed to the front light-transmitting cover 10 and the back plate 20 by adhesive bonding. Alternatively, the rigid support can be installed by setting structures for positioning the rigid support on the front light-transmitting cover 10 and the back plate 20 respectively. The rigid support can be set as multiple independent components and distributed around the battery string 30 to form multi-point support. The rigid support can also be set as a ring-shaped support frame structure, with the battery string 30 set inside the frame. In addition, in a specific orientation, the rigid support can be set inside the adhesive film sealing layer 40 or outside the adhesive film sealing layer 40.

[0046] Rigid support members can improve the support strength for the front light-transmitting cover and the back plate, and also facilitate maintaining the predetermined gap between the battery string and the front light-transmitting cover. In actual design, the predetermined gap between the battery string and the front light-transmitting cover can be set to 2-5mm. Of course, it can also be set to be larger or smaller depending on the actual space available.

[0047] As mentioned above, the photovoltaic module of this utility model can be configured as a double-glass encapsulation. When configured as a double-glass encapsulation, the back sheet 20 can be configured as a back sheet glass.

[0048] As one embodiment of this utility model, the battery string 30 may include a crystalline silicon heterojunction solar cell.

[0049] In the specific production of the photovoltaic module of this utility model, the following production process can be adopted (taking double-glass encapsulation as an example): A ring of butyl rubber (sealing film 40) is applied to the back glass surface parallel to the long and short sides, controlling the distance between the butyl rubber and the short and long sides of the glass to be 2mm-3mm, and the thickness of the butyl rubber to be 1.5mm-2mm. Then, a second encapsulation film is applied to the back glass surface, controlling the distance between the encapsulation film and the butyl rubber to be 3mm-4mm. The cell string 30 (crystalline silicon heterojunction solar cell) is applied to the surface of the second encapsulation film. Finally, the front light-transmitting cover 10 is closed. A sample of the photovoltaic module is obtained through the above application method. The sample is placed in a laminator and laminated by vacuuming the cavity 70 at a lamination temperature of 145℃-150℃ (generally 5-10 minutes) to obtain the laminated part. Then, the normal frame assembly and junction box installation are carried out.

[0050] This invention eliminates the first encapsulating film layer, allowing sunlight to pass directly through the front light-transmitting cover 10 and reach the surface of the battery string 30, significantly improving the light utilization rate of the battery string 30 and thus increasing the module power. This invention can protect not only unlaminated samples but also laminated components.

[0051] The following specific embodiments further illustrate the beneficial effects of this invention on photovoltaic modules, as shown in Table 1 below:

[0052]

[0053] Table 1 shows the test values ​​of various performance parameters of photovoltaic modules formed by encapsulating five battery strings of the same specifications using the photovoltaic module encapsulation method described in this application; Comparative Examples 1-5 show the test values ​​of various performance parameters of photovoltaic modules formed by encapsulating five battery strings of the same specifications (which are also the same specifications as the battery strings in the examples) using the encapsulation structure in the prior art where there is an adhesive film layer between the front of the battery string and the front light-transmitting cover. By setting up multiple sets of examples and comparative examples, errors can be avoided.

[0054] The performance indicators are as follows:

[0055] Pmax: Component power, in watts (W);

[0056] Vmp: Component operating voltage, in volts (V);

[0057] Imp: Component operating current, in amperes (A);

[0058] Voc: Component open-circuit voltage, in volts (V);

[0059] Isc: Component short-circuit current, in amperes (A);

[0060] FF: Component fill factor, %.

[0061] Analysis of the table shows that the performance of the photovoltaic module in the embodiment is better than that of the photovoltaic module in the comparative example, which is most evident in the module power and module short-circuit current. The module power in the embodiment is about 5-7W higher than that in the comparative example. This is consistent with the technical effect brought about by eliminating the film layer between the battery string and the front light-transmitting cover mentioned above.

[0062] Furthermore, this utility model further illustrates the reliability of photovoltaic modules through specific embodiments and comparative examples, as shown in Table 2 below:

[0063]

[0064] Table 2 shows the DH test results for photovoltaic modules. The DH test item refers to the damp heat aging test, with test conditions of 85℃ and 85% humidity.

[0065] In Table 2, Examples 1-2 show the performance values ​​of photovoltaic modules formed using the packaging method of this invention; Comparative Examples 1 and 2 show the performance values ​​of photovoltaic modules formed using conventional packaging technology.

[0066] Wherein, initial power is: the power generated by the photovoltaic module in its initial state, in W;

[0067] DH1000h power refers to the power generated by the photovoltaic module after 1000 hours of humid heat aging, expressed in W.

[0068] IV decay is calculated as: (initial power - DH1000h power) / initial power, in percentage, representing the component power decay.

[0069] As can be seen from Table 2, the performance of Examples 1 and 2 is better than that of Comparative Examples 1 and 2. This indicates that the photovoltaic modules using the encapsulation structure of this invention have better resistance to damp heat than photovoltaic modules encapsulated using conventional technology.

[0070] The above are merely specific embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Those skilled in the art should understand that this utility model includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of this utility model will be included within the scope of the claims.

Claims

1. A photovoltaic module comprising a front light-transmitting cover (10), a back sheet (20), and a cell string (30) disposed between the front light-transmitting cover (10) and the back sheet (20), characterized in that, The battery string (30) is fixed on the back plate (20). The front of the battery string (30) faces the front light-transmitting cover (10) and forms a set gap. The photovoltaic module also includes an adhesive film sealing layer (40). The opposing surfaces of the front light-transmitting cover (10) and the back plate (20) are connected by the adhesive film sealing layer (40). The adhesive film sealing layer (40) surrounds the battery string (30) and together with the front light-transmitting cover (10) and the back plate (20), forms a cavity (70) that seals the battery string (30). The cavity (70) is set to a vacuum.

2. The photovoltaic module of claim 1, wherein, The photovoltaic module also includes a second adhesive film layer (50), and the back side of the battery string (30) is bonded to the surface of the back sheet (20) through the second adhesive film layer (50).

3. The photovoltaic module of claim 2, wherein, The adhesive film sealing layer (40) and the second adhesive film layer (50) are connected.

4. The photovoltaic module of claim 2, wherein, The backplate (20) has an adhesive groove formed on its surface for mounting the battery string (30). The adhesive groove is opposite to the back of the battery string. The second adhesive film layer (50) can fill the adhesive groove to strengthen the connection between the second adhesive film layer (50) and the backplate (20).

5. The photovoltaic module according to any one of claims 1 to 4, characterized in that, The adhesive film sealing layer (40) is made of butyl rubber.

6. The photovoltaic module according to any one of claims 1 to 4, characterized in that, The distance between the adhesive film sealing layer (40) and the edge of the back plate (20) is 0 to 3 mm, and the width of the adhesive film sealing layer (40) is set to 5 mm to 10 mm.

7. The photovoltaic module according to any one of claims 1 to 4, characterized in that, The battery string (30) includes crystalline silicon heterojunction solar cells.

8. The photovoltaic module according to any one of claims 1 to 4, characterized in that, The set gap between the battery string (30) and the front light-transmitting cover (10) is 2mm to 5mm.

9. The photovoltaic module according to any one of claims 1 to 4, characterized in that, The photovoltaic module includes an adsorption layer (60) disposed in the cavity (70) and located on the side of the battery string (30), the adsorption layer (60) being used to absorb water vapor.

10. The photovoltaic module according to any one of claims 1 to 4, characterized in that, The photovoltaic module also includes a rigid support member. The rigid support member is provided between the front light-transmitting cover (10) and the back plate (20). The rigid support member is used to rigidly support the front light-transmitting cover (10) and the back plate (20) and maintain the set gap between the front light-transmitting cover (10) and the back plate (20).

Images