Recycling method of photovoltaic module

Abstract

The invention discloses a recovery method of a photovoltaic module, the photovoltaic module comprises a backboard, a wrapping layer, glass, a frame and a junction box, the recovery method comprises the following steps: identifying the size of the frame and positioning the frame and the junction box; dismantling the junction box and the frame to form a second dismantling part with a back plate, glass and a wrapping layer; identifying and sorting a second disassembly part with crack-free glass and a second disassembly part with crack glass; the cracked glass on the second dismantling part with the cracked glass is dismantled; the back plate and the crack-free glass on the second dismantling part with the crack-free glass are dismantled; and carrying out anaerobic low-temperature pyrolysis on a back plate-containing wrapping layer and / or a wrapping layer. Therefore, the recovery speed of the photovoltaic module can be increased, the recovery rate can be increased, the transfer cost and the material loss can be reduced, concentrated recovery of all components in the photovoltaic module is facilitated, and certain popularization value is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic components, and in particular to a method for recycling photovoltaic components. Background Art

[0002] Resource recycling is an important means to achieve carbon emission reduction. In the context of carbon peak and carbon neutrality, various national ministries and commissions have introduced various policies to include the secondary utilization of photovoltaic modules and power batteries in the national key development direction. Based on the dual carbon goals and the scientific and technological innovation plan in the energy field, the project focuses on the recycling and recycling technology of failed photovoltaic modules and power batteries, and breaks through the on-site disassembly and recycling technology of photovoltaic modules and the key technologies and equipment for the safe cascade utilization of power batteries. It focuses on solving the on-site low-cost disassembly and harmless recycling technology of photovoltaic modules, the secondary safety utilization of power batteries and AI intelligent detection and monitoring technology, as well as the development of green packaging materials, to achieve green manufacturing and harmless recycling of photovoltaic modules from the source of the product.

[0003] Photovoltaic modules are devices that can convert solar energy into electrical energy. Photovoltaic modules include frames, junction boxes, and stacked from bottom to top, backplane (or glass substrate), organic adhesive layer (EVA or POE, etc.), battery layer, organic bonding layer (EVA or POE, etc.), and glass substrate. Among them, most of the components such as silicon, aluminum, silver, and copper in the glass substrate, backplane, and battery layer can be recycled and reused.

[0004] At present, the recycling of photovoltaic modules is decentralized. For example, the junction box and frame disassembly plan, the broken module glass recycling plan, the crack-free glass recycling plan, the battery cell or silicon powder recycling plan, etc. Each plan is implemented independently. Although an upstream and downstream industrial chain has been formed, many components that are not the target products of each plan suffer huge losses.

[0005] Therefore, how to recover the components in photovoltaic modules should be the focus of technical personnel in this field. Summary of the invention

[0006] The purpose of the present invention is to provide a method for recycling photovoltaic modules, which can speed up the recycling speed of photovoltaic modules, improve the recovery rate of each component in the photovoltaic modules, and reduce the loss of each component in the photovoltaic modules. The photovoltaic modules include a back sheet, a wrapping layer, glass, a frame and a junction box. The recycling method includes the following steps:

[0007] Identify border size and position border;

[0008] Locate the junction box;

[0009] The junction box is removed to form a first disassembled component having a back plate, a frame, a glass and a wrapping layer;

[0010] The frame is removed to form a second disassembled component having a back plate, glass and a wrapping layer, wherein the glass includes crack-free glass and cracked glass;

[0011] identifying a second disassembled component having uncracked glass;

[0012] identifying a second disassembled component having cracked glass;

[0013] sorting the second disassembled parts having crack-free glass and the second disassembled parts having cracked glass;

[0014] Removing the cracked glass from the second dismantling component having the cracked glass, to obtain a backplane and a wrapping layer including a backplane;

[0015] Removing the back plate on the second disassembled component with the crack-free glass to obtain a third disassembled component with a wrapping layer and the crack-free glass;

[0016] Remove the crack-free glass on the third disassembled component to obtain the wrapping layer;

[0017] The back sheet-containing wrapping layer and / or the wrapping layer are pyrolyzed at low temperature without oxygen to obtain a gaseous component and a solid component.

[0018] Preferably, after the frame is removed, the second disassembly component is preheated.

[0019] Preferably, the preheating temperature ranges from 90-150°C

[0020] Preferably, before removing the cracked glass on the second disassembling component having the cracked glass, the cracked glass is broken.

[0021] Preferably, before removing the back panel on the second dismantling component with the crack-free glass, the second dismantling component with the crack-free glass is heated.

[0022] Preferably, the heating temperature ranges from 150-200°C.

[0023] Preferably, before the oxygen-free low-temperature pyrolysis of the backboard-containing wrapping layer and / or the wrapping layer, the backboard-containing wrapping layer and / or the wrapping layer are crushed to obtain wrapping layer fragments.

[0024] Preferably, the size of the envelope fragments is less than 5 cm x 5 cm.

[0025] Preferably, after the oxygen-free low-temperature pyrolysis of the backboard-containing wrapping layer and / or the wrapping layer, the gaseous component is condensed or cooled by heat exchange to obtain a liquid component.

[0026] Furthermore, the solid components include carbon black, silicon flakes, metals and residual glass.

[0027] Due to the adoption of the above technical solution, the technical effects achieved by the present invention are:

[0028] The decentralized recovery method pays more attention to the recovery of a single component and does not care much about the loss of other components except the target product. Compared with the current decentralized recovery method, the recovery method provided by the present invention has a higher degree of coordination between the steps, can recover each component to the maximum extent, reduce the loss of each component in the photovoltaic module, thereby improving the recovery rate of each component in the photovoltaic module, and at the same time saves the transportation process between the decentralized recovery methods, thereby accelerating the recovery speed of the photovoltaic module. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present invention provides a method for recycling a photovoltaic module, wherein the photovoltaic module comprises a back plate, a wrapping layer, glass, a frame and a junction box, and the recycling method comprises the following steps:

[0031] Identify border size and position border;

[0032] Locate the junction box;

[0033] The junction box is removed to form a first disassembled component having a back plate, a frame, a glass and a wrapping layer;

[0034] The frame is removed to form a second disassembled component having a back plate, glass and a wrapping layer, wherein the glass includes crack-free glass and cracked glass;

[0035] identifying a second disassembled component having uncracked glass;

[0036] identifying a second disassembled component having cracked glass;

[0037] sorting the second disassembled parts having crack-free glass and the second disassembled parts having cracked glass;

[0038] Removing the cracked glass from the second dismantling component having the cracked glass, to obtain a backplane and a wrapping layer including a backplane;

[0039] Removing the back plate on the second disassembled component with the crack-free glass to obtain a third disassembled component with a wrapping layer and the crack-free glass;

[0040] Remove the crack-free glass on the third disassembled part to obtain the wrapping layer.

[0041] The back sheet-containing wrapping layer and / or the wrapping layer are pyrolyzed at low temperature without oxygen to obtain a gaseous component and a solid component.

[0042] In some embodiments, a visual recognition system is used to automatically identify the frame size, position the frame, and position the junction box. The size automatically recognized by the visual recognition system is greater than 1950x992mm (LxW), which can achieve accurate positioning of the junction box, intelligent grasping and removal, and the removed junction box is transferred to the junction box collection box through the grasping mechanism. It can also automatically identify the position of the frame, remove the frame through mechanical support mechanical force, and transfer the removed frame to the frame collection box through the grasping mechanism.

[0043] Some of the retired photovoltaic modules have broken glass due to natural phenomena or cracked glass due to external forces during disassembly. At the same time, some photovoltaic modules have glass without cracks from the beginning to the end. Different recycling methods are needed for photovoltaic modules with cracked glass and photovoltaic modules with crack-free glass to maximize the recycling value of the glass in photovoltaic modules.

[0044] Therefore, in some embodiments, after removing the junction box and the frame, a visual recognition system is used to identify whether the glass on the second disassembled component is broken, so as to sort the second disassembled component into a second disassembled component with crack-free glass and a second disassembled component with cracked glass. Then, for the second disassembled component with cracked glass, a blunt-angle milling cutter is used to remove the glass on the second disassembled component from the second disassembled component, and the removed glass will be collected. For the second disassembled component with crack-free glass, a scraper is first used to scrape out a clampable portion at the edge of the back panel, and then the entire back panel is completely peeled off and the back panel is collected; then, a scraper is used to completely scrape the wrapping layer from the third disassembled component, so as to maintain the integrity of the crack-free glass, and the crack-free glass is collected. Preferably, after the wrapping layer is completely scraped off from the crack-free glass, the residue of the organic bonding layer on the glass is less than 3%, and the integrity of the crack-free glass is ≥99%.

[0045] In the process flow, after sorting out the second disassembly component with crack-free glass and the second disassembly component with cracked glass, the glass and the back panel on the second disassembly component are immediately removed. Therefore, in some embodiments, in order to speed up the removal of the glass and the back panel, it is necessary to preheat the second disassembly component before sorting out the second disassembly component with crack-free glass and the second disassembly component with cracked glass. The preheating temperature is controlled at 90-150°C to soften the organic bonding layer in the second disassembly component, thereby reducing the bonding strength of the organic bonding layer to the glass and the back panel, and removing the glass and the back panel from the second disassembly component more quickly.

[0046] In some embodiments, in addition to preheating the second disassembled component, for the second disassembled component with cracked glass, the cracked glass on the preheated second disassembled component is broken, for example, by rolling. Due to the presence of the backplane, organic adhesive layer and welding strip (including bus bar) in the backplane wrapping layer, the second disassembled component at this time is still in sheet form, and there are gaps between the glass fragments formed after the glass is broken, which makes it convenient for the obtuse-angle milling cutter to penetrate into the gaps, so that the glass can be removed from the second disassembled component more quickly. The crushing process takes a short time to ensure that the temperature of the preheated second disassembled component does not drop much, and preferably the temperature is almost unchanged, and the bonding strength of the organic adhesive layer to the glass fragments is low enough to ensure that the glass can be quickly peeled off.

[0047] In order to maximize the recycling value of the back panel and the crack-free glass on the second disassembled component with crack-free glass, it is necessary to maintain the integrity of the back panel and the crack-free glass when removing them from the second disassembled component with crack-free glass. Therefore, in some embodiments, before removing the back panel on the second disassembled component with crack-free glass, the second disassembled component is heated in the form of single-sided heating, and the heating temperature is controlled between 150-200°C to melt the organic bonding layer in the second disassembled component, thereby reducing the bonding strength of the organic bonding layer to the back panel and the crack-free glass, and removing the back panel and the crack-free glass more quickly.

[0048] In some embodiments, before the backboard-containing wrapping layer and / or the wrapping layer are subjected to anaerobic low-temperature pyrolysis, the backboard-containing wrapping layer and / or the wrapping layer are subjected to shearing crushing treatment to obtain wrapping layer fragments, so as to ensure that the wrapping layer fragments are evenly heated and rapidly cracked during anaerobic low-temperature pyrolysis. Preferably, the size of the wrapping layer fragments is less than 5 cm×5 cm, so that the wrapping layer fragments can be pyrolyzed more quickly and evenly, and the various components in the wrapping layer fragments can be more fully separated from each other, which is conducive to improving the recovery rate of each component.

[0049] In some embodiments, the encapsulation layer fragments are placed in a closed oxygen-free low-temperature pyrolysis furnace, the oxygen-free low-temperature pyrolysis temperature is 300-450°C, and the gaseous components and solid components are obtained after the oxygen-free low-temperature pyrolysis. During the oxygen-free low-temperature pyrolysis of the encapsulation layer fragments, the organic macromolecular segments are broken to form pyrolysis gas and carbon black, so that the metals and silicon wafers in the encapsulation layer fragments and the residual glass on the surface of the encapsulation layer are separated. Further, the gaseous component is cooled, and the cooling method includes condensation or heat exchange cooling. The components with higher boiling points in the gaseous components are cooled into liquid components, which are bio-oil; the components with lower boiling points in the gaseous components are collected separately, and can also be burned to provide heat for the oxygen-free low-temperature pyrolysis furnace, thereby reducing energy consumption. At the same time, the solid component is cooled, and the cooling method is heat exchange cooling, so that the temperature of the solid component after cooling is ≤75°C. The solid components include carbon black, metal, silicon battery cells and residual glass, wherein the residual glass is glass slag that adheres to the surface of the wrapping layer or the wrapping layer containing the backboard or is partially embedded in the wrapping layer or the wrapping layer containing the backboard during the process of removing the glass with a blunt-angle milling cutter. Such glass slag is not completely removed by the blunt-angle milling cutter, resulting in a small amount of residual glass attached to the wrapping layer fragments when they enter the oxygen-free low-temperature pyrolysis furnace.

[0050] Parts not involved in the present invention are the same as the prior art or can be implemented by the prior art. Although the embodiments of the present invention have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for recycling a photovoltaic module, wherein the photovoltaic module comprises a back sheet, a wrapping layer, glass, a frame and a junction box, characterized in that: The recycling method includes the following steps: Identifying the frame size and positioning the frame; positioning the junction box; The junction box is removed to form a first disassembled component having the back plate, the frame, the glass and the wrapping layer; The frame is removed to form a second disassembled component having the back plate, the glass and the wrapping layer, wherein the glass includes crack-free glass and cracked glass; identifying a second disassembled component having the crack-free glass; identifying a second disassembled component having the cracked glass; sorting the second disassembled component having the crack-free glass and the second disassembled component having the cracked glass; Removing the cracked glass from the second disassembly component having the cracked glass to obtain a backplane-containing wrapping layer having the backplane and the wrapping layer; Removing the back plate from the second disassembled component having the crack-free glass to obtain a third disassembled component having the wrapping layer and the crack-free glass; Removing the crack-free glass on the third disassembly component to obtain the wrapping layer; The backboard-containing wrapping layer and / or the wrapping layer are pyrolyzed at low temperature without oxygen to obtain a gaseous component and a solid component.

2. A method for recycling photovoltaic modules according to claim 1, characterized in that: After removing the frame, preheat the second disassembly component.

3. A method for recycling photovoltaic modules according to claim 2, characterized in that: The preheating temperature ranges from 90 to 150°C.

4. A method for recycling photovoltaic modules as claimed in claim 2, characterized in that: Before removing the cracked glass from the second disassembling component having the cracked glass, the cracked glass is broken.

5. A method for recycling photovoltaic modules according to claim 2, characterized in that: Before removing the back panel from the second disassembling component having the crack-free glass, the second disassembling component having the crack-free glass is heated.

6. A method for recycling photovoltaic modules according to claim 5, characterized in that: The heating temperature ranges from 150 to 200°C.

7. A method for recycling photovoltaic modules according to any one of claims 1 to 6, characterized in that: Before the oxygen-free low-temperature pyrolysis of the backboard-containing wrapping layer and / or the wrapping layer, the backboard-containing wrapping layer and / or the wrapping layer are crushed to obtain wrapping layer fragments.

8. A method for recycling photovoltaic modules according to claim 7, characterized in that: The size of the envelope fragments is less than 5 cm×5 cm.

9. A method for recycling photovoltaic modules according to claim 1, characterized in that: After the backboard-containing wrapping layer and / or the wrapping layer are pyrolyzed at low temperature without oxygen, the gaseous component is condensed or cooled by heat exchange to obtain a liquid component.

10. A method for recycling photovoltaic modules according to claim 1, characterized in that: The solid components include carbon black, silicon flakes, metals and residual glass.