Encapsulation process of BIPV photovoltaic modules using laser additive manufacturing technology

Abstract

The present invention relates to a packaging process for BIPV photovoltaic modules using laser additive manufacturing technology, which is to use laser additive manufacturing technology to prepare a silicon oxide layer around a photovoltaic cover plate, cover the photovoltaic cover plate with a PVB film, and then combine and laminate the photovoltaic module, and finally use a laser galvanometer to weld the interface between the silicon oxide layer and the photovoltaic module to obtain a BIPV photovoltaic module. The packaging process of the present invention can increase the sealing performance of the photovoltaic module, meet the fire resistance requirements of the BIPV industry for the photovoltaic module, and expand the application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of production of BIPV photovoltaic modules, and in particular to a packaging process of BIPV photovoltaic modules using laser additive manufacturing technology. Background Art

[0002] As a green and clean energy, solar energy has been gradually widely used as the society's environmental awareness increases. Building Integrated Photovoltaic, or BIPV for short, is a technology that integrates solar power generation (photovoltaic) products into buildings, breaking the barriers between the traditional photovoltaic industry and the construction industry. Existing photovoltaic modules used in BIPV often have many disadvantages. For example, the power generation efficiency of photovoltaic modules is greatly affected by light transmittance, and the modules have poor control effects on temperature and light. In addition, bubbles and sealing problems have also become a major factor affecting the power generation of modules. Therefore, the service life of photovoltaic modules is easily affected. In addition, BIPV also has high requirements for the fire resistance of photovoltaic modules, and the application of existing photovoltaic modules is subject to certain restrictions. Summary of the invention

[0003] The present invention provides a packaging process for BIPV photovoltaic modules using laser additive manufacturing technology. The packaging process can increase the sealing performance of photovoltaic modules and achieve the effect of sealing water vapor, thereby meeting the BIPV industry's demand for fire resistance of photovoltaic modules, improving the use effect and service life of photovoltaic modules, and expanding application prospects.

[0004] The technical solution adopted by the present invention is: a packaging process of a BIPV photovoltaic module using laser additive manufacturing technology, comprising the following steps:

[0005] a: Clean and dry the photovoltaic cover;

[0006] b: A silicon oxide layer with a certain thickness is prepared around the photovoltaic cover plate using laser additive manufacturing technology;

[0007] c: Covering the photovoltaic cover plate treated in step b with a PVB film, then combining it with the photovoltaic module to obtain a module, and then laminating and packaging the module;

[0008] d: The interface between the silicon oxide layer and the photovoltaic module is welded using a galvanometer laser welding machine to obtain a BIPV photovoltaic module;

[0009] The thickness of the silicon oxide layer is 50-200 μm greater than that of the PVB film.

[0010] In step a, the photovoltaic cover plate may be made of ultra-white tempered glass, soda-lime glass, borosilicate glass or stainless steel sheet.

[0011] In step b, the laser used in the laser additive manufacturing technology is one of a carbon dioxide laser, a continuous fiber laser, a nanosecond laser, and a picosecond laser;

[0012] Continuous fiber laser, the wavelength can be 1064nm infrared laser, 532nm green laser, or 355nm ultraviolet laser, the laser power is 300~3000w;

[0013] Nanosecond laser, the wavelength can be 1064nm infrared laser, 532nm green laser, or 355nm ultraviolet laser, the pulse width is between 1ns and 500ns, and the laser power is 3 to 200w;

[0014] Picosecond lasers can be 1064nm infrared lasers, 532nm green lasers, or 355nm ultraviolet lasers, with a pulse width of 0.5ps to 800ps and a laser power of 3 to 200w.

[0015] In step b, the specific method of preparing the silicon oxide layer using laser additive manufacturing technology is any one of the following:

[0016] The silicon oxide layer can be prepared on the cover glass by focusing the laser on the cover glass and coaxially feeding the silicon oxide powder;

[0017] Alternatively, a certain thickness of nano-silicon oxide powder is laid in advance, and then laser shaping is used to prepare a silicon oxide layer;

[0018] Alternatively, a silicon oxide layer is prepared by coating a silicon oxide powder suspension solution on the cover glass, curing it, and then heating and shaping it with a laser.

[0019] The main component of silicon oxide powder used in laser additive is SiO 2 In order to better absorb the laser, sodium ion salt or potassium ion salt can be added to the powder. + Salt or K + The weight ratio of sodium ions in the silicon oxide powder is 0.01% to 0.5%. The sodium ion salt can be sodium chloride, sodium fluoride, sodium bromide, sodium sulfate, etc., and the potassium ion salt can be potassium chloride, potassium fluoride, potassium bromide, potassium sulfate, etc.

[0020] Laser additive operation is to focus the laser onto the surface of the photovoltaic cover after collimation. The focused spot is circular depending on the selected focusing mirror. The laser can also be shaped into a square spot by optical fiber shaping, which will greatly reduce the time consumption of production.

[0021] The laser movement in the laser additive operation can be performed by scanning with a galvanometer, or by reciprocating motion of a focusing mirror driven by a linear motor;

[0022] The thickness of the silicon oxide layer is optimized according to the thickness of the PVB film, and is required to be 50 to 200 μm thicker than the thickness of the PVB film. The thickness needs to be optimized according to the actual shrinkage of the PVB.

[0023] In step c, the photovoltaic component may be a crystalline silicon solar cell component connected in series, or may be a thin-film solar cell component such as copper indium gallium selenide, cadmium telluride, perovskite, graphene, etc.

[0024] In step d, the laser used for laser galvanometer welding may be a picosecond infrared laser with a laser wavelength of 1064 nm; or a femtosecond laser with a laser wavelength of 1064 nm;

[0025] Laser galvanometer welding operation: when the photovoltaic cover is made of transparent materials such as ultra-white tempered glass, soda-lime glass, borosilicate glass, etc., the laser emitted by the laser can be incident from the photovoltaic module side for focusing, or it can be incident from the photovoltaic cover side for focusing; when the photovoltaic cover is a stainless steel sheet, the laser emitted by the laser can be incident from the photovoltaic module side for focusing;

[0026] The scanning speed of the galvanometer is 1m / s~10m / s.

[0027] The packaging process of the present invention applies laser additive manufacturing technology for the first time to the packaging of photovoltaic modules for BIPV. Through the above packaging process, the sealing performance of the module can be increased to achieve the effect of sealing water vapor, thereby meeting the BIPV industry's demand for the fire resistance of photovoltaic modules, improving the use effect and service life of photovoltaic modules, and expanding the application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a SEM surface morphology image (200,000 times) of silicon oxide prepared by a continuous fiber laser in the packaging process of the BIPV photovoltaic module using laser additive manufacturing technology of the present invention;

[0029] Figure 2 This is a SEM surface morphology image (200,000 times) of silicon oxide prepared by a picosecond laser in the packaging process of the BIPV photovoltaic module using laser additive manufacturing technology in the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with specific embodiments.

[0031] Example

[0032] This embodiment relates to a packaging process for BIPV photovoltaic modules using laser additive manufacturing technology, which specifically includes the following steps:

[0033] a: Use ultrasonic waves, roller brushes or high-pressure water spray to clean the photovoltaic cover, and then use a hot air knife to blow dry the cleaned photovoltaic cover; the photovoltaic cover can be made of ultra-white tempered glass, soda-lime glass, borosilicate glass or stainless steel;

[0034] b: A silicon oxide layer with a certain thickness is prepared around the photovoltaic cover plate by laser additive manufacturing technology; the thickness of the silicon oxide layer is optimized according to the thickness of the PVB film covered behind it, and is required to be 50-200 μm thicker than the thickness of the PVB film. The thickness needs to be optimized according to the actual shrinkage of PVB; the main component of the silicon oxide powder used to prepare the silicon oxide layer is SiO 2 In order to better absorb the laser, sodium ion salt or potassium ion salt can be added to the powder. + Salt or K + The weight ratio of sodium ions in the silicon oxide powder is 0.01% to 0.5%. The sodium ion salt can be sodium chloride, sodium fluoride, sodium bromide, sodium sulfate, etc., and the potassium ion salt can be potassium chloride, potassium fluoride, potassium bromide, potassium sulfate, etc.;

[0035] c: Covering the photovoltaic cover plate with the silicon oxide layer with a PVB film, then combining it with the photovoltaic module to obtain a module, and using a laminating device to laminate and package the combined module; the photovoltaic module can be a series-connected crystalline silicon solar cell module, a copper indium gallium selenide thin-film solar cell module, a cadmium telluride thin-film solar cell module, a perovskite thin-film battery module or a graphene thin-film solar cell module;

[0036] d: Use a galvanometer laser welding machine to focus the laser on the interface between the silicon oxide layer and the photovoltaic module, and use a galvanometer to quickly scan to complete the welding of the four sides of the module to obtain a BIPV photovoltaic module.

[0037] In the embodiment, the various equipment, preparation conditions, scanning paths used in the laser additive manufacturing technology, and the laser equipment, focusing paths and other factors used in the galvanometer laser welding machine are specifically shown in the following table:

[0038]

[0039]

[0040] At present, the sealing performance is generally tested by high-voltage wet leakage detection, which requires a composite insulation resistance greater than 40MΩ / m 2, the efficiency drop in double 85 environment for 500h is less than 0.5%; the fire resistance evaluation grade standard is T / CSTM 00260-2021 "Test method for fire protection grade of roof crystalline silicon photovoltaic and corrugated steel plate components", and the evaluation standard is: the fire protection grades are AA / AB / AC / BA / BB / BC respectively.

[0041] The performance test results (such as sealing performance, fire resistance performance, etc.) of the BIPV photovoltaic modules obtained by the above embodiments are shown in the following table.

[0042] Performance Indicators Example 1 <![CDATA[63MΩ / m 2 , double 85 environment 500h efficiency drops by 0.4%; fire resistance rating standard AC]]> Example 2 <![CDATA[83MΩ / m 2 , double 85 environment 500h efficiency drops by 0.4%; fire resistance rating standard AA]]> Example 3 <![CDATA[63MΩ / m 2 , double 85 environment 500h efficiency drops by 0.4%; fire resistance rating standard AC]]> Example 4 <![CDATA[83MΩ / m 2 , double 85 environment 500h efficiency drops by 0.4%; fire resistance rating standard AA]]>

[0043] Regarding sealing, it depends on the thickness of the silicon oxide layer and the order of operations for preparing the silicon oxide layer using laser additive manufacturing. The thickness of the silicon oxide layer is determined by the thickness of the crystalline silicon, the thickness of the welding strip, and the thickness of the PVB / EVA film, and the thickness ranges from 200μm to 500μm. In order to meet the welding sealing requirements when welding glass, the thickness between the glasses must be less than 1 / 4 wavelength (that is, 266nm for 1064nm as an example). The thickness between the glasses in the actual components is much greater than 1 / 4 laser wavelength, reaching the level of hundreds of μm. Therefore, it is necessary to use additive technology in advance to prepare a layer of silicon oxide in the circumference of the photovoltaic cover, and then cover it with PVB film, combine it with the photovoltaic components, laminate and package it, and weld it. Otherwise, the welding sealing requirements cannot be met.

[0044] Regarding the lasers used in laser additive manufacturing technology, the quality and thickness accuracy of silicon oxide obtained by continuous fiber laser and carbon dioxide laser cladding are slightly worse, while the quality and thickness accuracy of silicon oxide obtained by nanosecond laser and picosecond laser cladding are better, among which picosecond laser is the best.

[0045] like Figure 1 The figure shows the SEM surface morphology of silicon oxide prepared by continuous fiber laser (200,000 times). Figure 2 The figure shows the SEM surface morphology of silicon oxide prepared by picosecond laser (200,000 times). It can be clearly seen that the silicon oxide layer prepared by picosecond laser is denser and has better film quality, while the silicon oxide layer prepared by continuous fiber laser has larger particles.

[0046] Regarding galvanometer laser welding machines, the welding speed is affected by the different lasers used and the different repetition frequencies. In addition, the high-pulse-capacity femtosecond lasers not only have fast speeds, but also better welding effects.

[0047] When the photovoltaic cover is an ultra-white tempered glass plate, soda-lime glass, or borosilicate glass, since the laser can penetrate glass, the laser emitted by the galvanometer laser welding machine can be incident and focused from the side of the photovoltaic module or from the side of the photovoltaic cover; when the photovoltaic cover is a stainless steel sheet, since the laser cannot penetrate stainless steel, the laser emitted by the galvanometer laser welding machine needs to be incident and focused from the side of the photovoltaic module.

[0048] Comparative Example

[0049] Existing component packaging process

[0050] a: Use ultrasonic waves, roller brushes or high-pressure water spray to clean the photovoltaic cover, and then use a hot air knife to blow dry the cleaned photovoltaic cover; the photovoltaic cover can be made of ultra-white tempered glass, soda-lime glass, borosilicate glass or stainless steel;

[0051] b: Cover the photovoltaic cover plate and the power generation glass with PVB film, cover the edges with butyl film, and use laminating equipment to laminate and package the assembled modules;

[0052] Performance Indicators Comparative Example <![CDATA[45MΩ / m 2 , double 85 environment 500h efficiency drops by 0.8%; fire resistance evaluation grade standard no]]>

[0053] Through comparative examples and comparison with existing component packaging processes, it was found that the current packaging process's efficiency drop rate in a double 85 environment for 500h and fire resistance evaluation grade standards cannot meet the sealing requirements.

[0054] The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technical solution obtained by any technician familiar with the field within the technical scope disclosed by the present invention by equivalent replacement or change based on the technical concept of the present invention should be included in the protection scope of the present invention.

Claims

1. A packaging process for BIPV photovoltaic modules using laser additive manufacturing technology, characterized in that The packaging process comprises the following steps: a: Clean and dry the photovoltaic cover; b: A silicon oxide layer with a certain thickness is prepared around the photovoltaic cover plate using laser additive manufacturing technology; c: Covering the photovoltaic cover plate treated in step b with a PVB film, then combining it with the photovoltaic module to obtain a module, and then laminating and packaging the module; d: The interface between the silicon oxide layer and the photovoltaic module is welded using a galvanometer laser welding machine to obtain a BIPV photovoltaic module; The thickness of the silicon oxide layer is 50 to 200 μm greater than the thickness of the PVB film; In step b, the laser used in the laser additive manufacturing technology is one of a carbon dioxide laser, a continuous fiber laser, a nanosecond laser, and a picosecond laser; The photovoltaic cover plate is selected from one of ultra-white tempered glass plates, soda-lime glass, borosilicate glass or stainless steel sheets.

2. The packaging process of BIPV photovoltaic modules using laser additive manufacturing technology according to claim 1 is characterized in that: In step b, the specific method of preparing the silicon oxide layer by laser additive manufacturing technology is any one of the following: Method 1: The laser emits laser light and focuses it on the photovoltaic cover plate, and silicon oxide powder is coaxially transported on the photovoltaic cover plate for preparation; Method 2: first lay a layer of silicon oxide powder on the photovoltaic cover plate, and then use a laser to heat and shape it; Method three: coating a suspension solution of silicon oxide powder on the photovoltaic cover plate, and after the suspension solution is solidified, using a laser to emit laser for heating and shaping.

3. The packaging process of BIPV photovoltaic modules using laser additive manufacturing technology according to claim 2 is characterized in that: The main components of the silicon oxide powder include silicon dioxide and sodium ion salt or potassium ion salt, the sodium ion salt or the potassium ion salt accounts for 0.01% to 0.5% of the silicon oxide powder, the sodium ion salt is sodium chloride, sodium fluoride, sodium bromide or sodium sulfate, and the potassium ion salt is potassium chloride, potassium fluoride, potassium bromide or potassium sulfate.

4. The packaging process of BIPV photovoltaic modules using laser additive manufacturing technology according to claim 2 is characterized in that: In step b, the laser additive manufacturing technology uses a galvanometer or a focusing mirror for scanning, and the laser emitted by the laser moves along the path scanned by the galvanometer or along the path driven by the linear motor to reciprocate the focusing mirror.

5. The packaging process of BIPV photovoltaic modules using laser additive manufacturing technology according to claim 1 is characterized in that: In step d, the laser used by the galvanometer laser welding machine is a picosecond infrared laser or a femtosecond laser.

6. The packaging process of BIPV photovoltaic modules using laser additive manufacturing technology according to claim 5 is characterized in that: In step d, when the photovoltaic cover is an ultra-white tempered glass plate, soda-lime glass, or borosilicate glass, the laser emitted by the galvanometer laser welding machine is incident from one side of the photovoltaic module for focusing, or is incident from one side of the photovoltaic cover for focusing; when the photovoltaic cover is a stainless steel sheet, the laser emitted by the galvanometer laser welding machine is incident from one side of the photovoltaic module for focusing.

7. The packaging process of BIPV photovoltaic modules using laser additive manufacturing technology according to claim 6 is characterized in that: In step d, a galvanometer is used for scanning during laser galvanometer welding, and the scanning speed is 1 m / s to 10 m / s.

8. The packaging process of BIPV photovoltaic modules using laser additive manufacturing technology according to claim 1 is characterized in that: The photovoltaic module is selected from a series-connected crystalline silicon solar cell module, a copper indium gallium selenide thin-film solar cell module, a cadmium telluride thin-film solar cell module, a perovskite thin-film battery module or a graphene thin-film solar cell module.

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