Photovoltaic backboard and BIPV photovoltaic assembly

Abstract

The utility model discloses a photovoltaic backboard, which is applied to a building integrated photovoltaics (BIPV) module and comprises an inorganic substrate, a first adhesive layer and a metal plate, and the metal plate is adhered to the surface of the inorganic substrate through the first adhesive layer. The utility model also discloses a BIPV photovoltaic assembly, which comprises the photovoltaic backboard, and a first packaging adhesive film, a battery piece, a second packaging adhesive film and a light-transmitting plate which are sequentially laminated on the surface of the metal plate of the photovoltaic backboard. The photovoltaic backplane provided by the utility model has good water vapor barrier performance and good heat dissipation capability, and the BIPV photovoltaic assembly with the photovoltaic backplane has good waterproof performance and long service life.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic components, in particular to a photovoltaic backboard and a BIPV photovoltaic component. Background Art

[0002] BIPV stands for Building Integrated Photovoltaics, which is a building integrated photovoltaic power station system that integrates solar panels into building facades, roofs, etc. BIPV photovoltaic modules, as the core components of the BIPV system, are devices that use the photovoltaic effect of semiconductor materials under light conditions to directly convert solar energy into electrical energy.

[0003] BIPV photovoltaic modules are mainly composed of glass, cells, backplanes and packaging materials. Among them, the cell is the core part, which is made of semiconductor materials that convert light into electrical energy. Commonly used semiconductor materials are monocrystalline silicon, polycrystalline silicon and amorphous silicon. Glass serves as a protective cover for the battery, playing the role of waterproof, dustproof, and UV resistance. The backplane protects and supports the cell. The packaging material is used to bond and package the cell, glass and backplane to form a complete BIPV photovoltaic module.

[0004] The existing BIPV photovoltaic modules have the following disadvantages: 1. Since the backplane is bonded to the cell, the cell releases heat during the process of absorbing sunlight, and the backplane has a slow heat dissipation and high temperature, which can easily damage the internal structure of the cell. 2. The backplane is mostly a multi-layer permeable polymer. Since the polymer has a certain degree of air permeability, air enters the cell from the backplane. The moisture in the air will cause the internal parts of the cell to rust, thereby reducing the service life of the BIPV photovoltaic module. Utility Model Content

[0005] The utility model aims to provide a photovoltaic backboard and a BIPV photovoltaic module to solve the problems of poor heat dissipation and poor water vapor barrier performance of the existing BIPV photovoltaic modules.

[0006] In order to achieve the above-mentioned purpose, the technical solution proposed by the utility model is:

[0007] The utility model provides a photovoltaic backboard, which is applied to BIPV photovoltaic components and comprises an inorganic substrate, a first adhesive layer and a metal plate. The metal plate is bonded to the surface of the inorganic substrate through the first adhesive layer.

[0008] Preferably, the outer surface of the inorganic substrate is coated with a waterproof sealing coating.

[0009] Preferably, a surface of the inorganic substrate facing the first adhesive layer is coated with a penetrating primer layer, and a surface of the penetrating primer layer facing the first adhesive layer is coated with a leveling layer.

[0010] Preferably, the metal plate is an aluminum alloy plate or a stainless steel plate, and the inorganic substrate is an asbestos-free fiber cement board or an asbestos-free calcium silicate board.

[0011] Preferably, the thickness of the inorganic substrate is 8 to 15 mm, the absolute dry density is ≥1.4 g / cm³, the air-dry flexural strength is ≥18 MPa, the saturated flexural strength is ≥15 MPa, the moisture content is 5 to 20%, and the fire rating is not lower than Class A.

[0012] Preferably, the leveling layer is formed by coating with water-based epoxy putty or UV putty, the penetrating primer layer is formed by coating with one of water-based polyurethane penetrating primer, water-based epoxy penetrating primer and UV penetrating primer, the waterproof sealing coating is formed by coating with water-based polyurethane waterproof sealing primer or water-based epoxy waterproof sealing primer, and the first adhesive layer is formed by coating with reactive polyurethane hot melt adhesive or solvent-free two-component polyurethane adhesive.

[0013] Preferably, the surface of the metal plate is coated with a white fluorocarbon coating.

[0014] The utility model also provides a BIPV photovoltaic assembly, which includes the photovoltaic backboard of the utility model, a first packaging film, a battery cell, a second packaging film and a light-transmitting plate which are sequentially stacked on the metal plate surface of the photovoltaic backboard.

[0015] Preferably, an insulating film is laminated between the battery cell and the first packaging film, and a second adhesive layer is provided on a surface of the insulating film facing the battery cell.

[0016] Preferably, the light-transmitting plate is made of tempered glass with a transmittance greater than or equal to 95%, the first packaging film and the second packaging film are made of PVB packaging film, EVA packaging film or POE packaging film, and the battery cell is a monocrystalline silicon battery cell or a polycrystalline silicon battery cell.

[0017] By adopting the above technical scheme, the beneficial effects of the utility model are as follows: the photovoltaic backplane of the utility model includes an inorganic substrate, a first adhesive layer and a metal plate. The inorganic substrate serves as the structural skeleton of the BIPV photovoltaic module, plays the role of support and rigid base plate, and meets the strength performance. The metal plate is compounded with the inorganic substrate through the first adhesive, which can effectively seal the pores and water vapor of the inorganic substrate, thereby ensuring the packaging quality of the BIPV photovoltaic module. The metal plate itself has high thermal conductivity, which can play a good role in heat dissipation, thereby helping to extend the service life of the BIPV photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a cross-sectional schematic diagram of the BIPV photovoltaic module of Example 1.

[0019] Figure 2 This is a schematic diagram of the structure of the photovoltaic backplane of the second embodiment.

[0020] Figure 3 It is a cross-sectional schematic diagram of the BIPV photovoltaic module of Example 3.

[0021] Among them: 1. Photovoltaic backplane; 11. Inorganic substrate; 12. First adhesive layer; 13. Metal plate; 14. Waterproof sealing coating; 15. Penetration primer layer; 16. Leveling layer; 2. First packaging film; 3. Battery cell; 4. Second packaging film; 5. Transparent plate; 6. Insulating film; 7. Second adhesive layer. DETAILED DESCRIPTION

[0022] The utility model is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0023] Embodiment 1

[0024] like Figure 1 As shown, the BIPV photovoltaic module of this embodiment includes a photovoltaic back sheet 1, a first packaging film 2, a battery cell 3, a second packaging film 4 and a light-transmitting plate 5. Among them, the photovoltaic back sheet 1 includes an inorganic substrate 11, a first adhesive layer 12 and a metal plate 13, the metal plate 13 is bonded to one side surface of the inorganic substrate 11 through the first adhesive layer 12, the battery cell 3 is compounded on the surface of the metal plate 13 through the first packaging film 2, and the light-transmitting plate 5 is compounded on the surface of the battery cell 3 through the second packaging film 4.

[0025] Specifically, the light-transmitting plate 5 is preferably made of ultra-white tempered glass, which has a light transmittance greater than or equal to 95% and has high light transmittance.

[0026] The first packaging film 2 and the second packaging film 4 can be made of PVB packaging film, EVA packaging film or POE packaging film, preferably PVB packaging film. Compared with EVA packaging film, PVB packaging film has better impact resistance, high light transmittance, low reflectivity and better UV resistance.

[0027] The cell 3 uses a monocrystalline silicon cell or a polycrystalline silicon cell, preferably a PERC crystalline silicon cell, which has a mature process and a high cost-performance ratio.

[0028] The metal plate 13 is made of aluminum alloy plate or stainless steel plate, and the thickness is preferably 0.4 to 0.5 mm. The surface of the metal plate 13 is flat and smooth, easy to produce, and has a high yield rate. When producing BIPV photovoltaic modules, the metal plate 13 is bonded and combined with the first packaging film 2 as the bonding layer of the photovoltaic backplane 1, and the encapsulated BIPV photovoltaic module has a good effect. The metal plate 13 and the inorganic substrate 11 are bonded together by the first adhesive layer 12, which can effectively seal the pores and water vapor of the inorganic substrate 11 and ensure the packaging quality of the BIPV photovoltaic module. The metal plate 13 itself has high thermal conductivity. The thermal conductivity of aluminum alloy is usually 210 to 250 W / (m·K), and the thermal conductivity of stainless steel is usually between 16 and 21 W / (m·K), which can play a good role in heat dissipation.

[0029] In order to improve the photoelectric conversion efficiency of the BIPV photovoltaic module, in a feasible option of the present embodiment, the surface of the metal plate 13 is coated with a white fluorocarbon coating, which has a very high solar reflectance and near-infrared reflectance. The solar reflectance is greater than or equal to 90%. The sunlight transmitted from the cell 3 can be effectively reflected back to the cell 3 for secondary absorption, thereby improving the photoelectric conversion efficiency of the BIPV photovoltaic module.

[0030] The first adhesive layer 12 uses reactive polyurethane hot melt adhesive or solvent-free two-component polyurethane adhesive. The first adhesive layer 12 bonds the inorganic substrate 11 and the metal plate 13 together, and has high bonding strength, high water resistance, high weather resistance, and excellent high and low temperature resistance.

[0031] The inorganic substrate 11 is made of asbestos-free fiber cement board or asbestos-free calcium silicate board. The inorganic substrate 11 serves as the structural skeleton of the BIPV photovoltaic module, plays the role of support and rigid base plate, and meets the strength performance. The inorganic substrate 11 preferably uses asbestos-free calcium silicate board. The thickness of the inorganic substrate 11 is 8 to 15 mm (preferably 8 to 10 mm), the absolute dry density is ≥1.4 g / cm³ (preferably 1.55 to 1.6 g / cm³), the air-dried flexural strength is ≥18MPa (preferably 20 MPa), the saturated flexural strength is ≥15MPa (preferably 16MPa), the moisture content is 5 to 20% (preferably 5 to 8%), and the fire rating is not lower than Class A.

[0032] The arrangement of the photovoltaic back sheet 1 of the present embodiment improves the waterproof performance and heat dissipation performance of the BIPV photovoltaic module, and helps to extend the service life of the BIPV photovoltaic module.

[0033] Embodiment 2

[0034] Please refer to Figure 2In order to improve the weather resistance of the BIPV photovoltaic module, this embodiment is improved on the basis of the first embodiment. In this embodiment, a waterproof sealing coating 14 is applied on the outer surface of the inorganic substrate 11, that is, the side and back of the inorganic substrate 11, for waterproofing and sealing the inorganic substrate 11. The waterproof sealing coating 14 is made of a water-based polyurethane waterproof sealing primer or a water-based epoxy waterproof sealing primer. The waterproof sealing coating 14 can improve the service life, water resistance, weather resistance, frost resistance, etc. of the photovoltaic backboard 1, and reduce the water absorption rate of the inorganic substrate 11.

[0035] A permeation primer layer 15 is coated on the surface of the inorganic substrate 11 facing the first adhesive layer 12. The permeation primer layer 15 is formed by coating with a water-based polyurethane permeation primer, a water-based epoxy permeation primer, or a UV permeation primer. The permeation primer layer 15 can improve the adhesion between the coating and the inorganic substrate 11 and reduce the water absorption rate of the inorganic substrate 11.

[0036] In order to improve the overall flatness of the inorganic substrate 11, a leveling layer 16 is coated on the surface of the penetration primer layer 15 facing the first adhesive layer 12. The leveling layer 16 is formed by coating with water-based epoxy putty or UV putty. The leveling layer 16 can fill the gaps and holes of the inorganic substrate 11, improve the overall flatness of the inorganic substrate 11, and ensure the bonding strength between the inorganic substrate 11 and the metal plate 13.

[0037] The photovoltaic backsheet 1 of this embodiment was tested according to the relevant items of JG / T 396-2012 "Non-load-bearing fiber reinforced cement board for exterior wall", and the performance of the photovoltaic backsheet 1 of this embodiment was tested according to the relevant items of GB / T 22412-2016 "Aluminum-plastic composite board for general decoration", and the test results are as follows:

[0038]

[0039]

[0040] It can be seen from the measured data that the physical properties of the photovoltaic backsheet 1 fully meet the requirements for use as an exterior wall panel.

[0041] Embodiment 3

[0042] Please refer to Figure 3In order to further improve the safety of the BIPV photovoltaic module, this embodiment is improved on the basis of the first embodiment. In this embodiment, an insulating film 6 is added between the battery cell 3 and the first packaging film 2. The surface of the insulating film 6 facing the battery cell 3 is coated with a second adhesive layer 7 to bond the insulating film 6 to the battery cell 3. The insulating film 6 is used for high-voltage insulation, improves the insulation performance of the entire BIPV photovoltaic module, protects the battery from direct contact with the metal plate 13, and prevents leakage and high-voltage breakdown risks. It can be understood that this embodiment can also be improved on the basis of the second embodiment.

[0043] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, those skilled in the art should understand that various changes in form and details of the present invention are within the scope of protection of the present invention without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A photovoltaic backsheet, characterized in that: include: An inorganic substrate (11), a first adhesive layer (12) and a metal plate (13), wherein the metal plate (13) is bonded to the surface of the inorganic substrate (11) via the first adhesive layer (12).

2. The photovoltaic backsheet according to claim 1, characterized in that: It also includes a waterproof sealing coating (14) coated on the outer surface of the inorganic substrate (11).

3. The photovoltaic backsheet according to claim 2, characterized in that: It also comprises a penetrating primer layer (15) and a leveling layer (16), wherein the penetrating primer layer (15) is coated on a surface of the inorganic substrate (11) facing the first adhesive layer (12), and the leveling layer (16) is coated on a surface of the penetrating primer layer (15) facing the first adhesive layer (12).

4. The photovoltaic backsheet according to claim 3, characterized in that: The metal plate (13) is an aluminum alloy plate or a stainless steel plate; The inorganic substrate (11) is an asbestos-free fiber cement board or an asbestos-free calcium silicate board.

5. The photovoltaic backsheet according to claim 4, characterized in that: The inorganic substrate (11) has a thickness of 8 to 15 mm, an absolute dry density of ≥1.4 g / cm³, an air-dry flexural strength of ≥18 MPa, a saturated flexural strength of ≥15 MPa, a moisture content of 5 to 20%, and a fire rating of not less than Class A.

6. The photovoltaic backsheet according to claim 4, characterized in that: The leveling layer (16) is formed by coating with water-based epoxy putty or UV putty; The penetrating primer layer (15) is formed by coating with one of waterborne polyurethane penetrating primer, waterborne epoxy penetrating primer and UV penetrating primer; The waterproof sealing coating (14) is formed by coating with a water-based polyurethane waterproof sealing primer or a water-based epoxy waterproof sealing primer; The first adhesive layer (12) is formed by coating reactive polyurethane hot melt adhesive or solvent-free two-component polyurethane adhesive.

7. The photovoltaic backsheet according to any one of claims 1 to 6, characterized in that: The surface of the metal plate (13) is coated with a white fluorocarbon coating.

8. A BIPV photovoltaic module, characterized in that: It comprises the photovoltaic back sheet (1) as claimed in any one of claims 1 to 7, a first packaging film (2), a battery cell (3), a second packaging film (4) and a light-transmitting plate (5) which are sequentially stacked on the surface of a metal plate (13).

9. The BIPV photovoltaic module according to claim 8, characterized in that: It also comprises an insulating film (6) which is stacked between the battery cell (3) and the first packaging adhesive film (2), and a second adhesive layer (7) is provided on a surface of the insulating film (6) facing the battery cell (3).

10. The BIPV photovoltaic module according to claim 8, characterized in that: The light-transmitting plate (5) is made of tempered glass with a light transmittance greater than or equal to 95%; The first packaging film (2) and the second packaging film (4) are made of PVB packaging film, EVA packaging film or POE packaging film; The cell (3) is a monocrystalline silicon cell or a polycrystalline silicon cell.

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