A high-efficiency preparation method and equipment for recycling photovoltaic modules

Abstract

The application relates to the technical field of photovoltaic module recycling, and discloses a high-efficiency preparation method and equipment for photovoltaic module recycling, which comprises the following steps: pretreating a photovoltaic module, wherein the pretreatment comprises cleaning, dust removal, junction box disassembly, aluminum frame removal and edge glue removal; identifying the cell piece area and the non-cell piece area of the photovoltaic module after the pretreatment based on machine vision; separating the EVA glue film of the cell piece area and the non-cell piece area based on laser cutting; separating the cell piece from the glass based on first laser scanning, and retaining the EVA glue film on the glass; breaking and sorting the separated cell piece; and performing glue removal treatment on the glass based on second laser scanning, and recycling the glass and the EVA glue film. The application realizes efficient, green and low-energy-consumption recycling of the photovoltaic module.

Description

Technical Field

[0001] This application relates to the field of photovoltaic module recycling technology, and in particular to an efficient preparation method and equipment for photovoltaic module recycling. Background Technology

[0002] The global solar photovoltaic panel recycling market is on the eve of industrialization, driven by the exponentially growing volume of waste (estimated to reach 78 million tons by 2050) and the strategic value of the circular economy. Its technological roadmap is showing a clear evolution from basic "downgraded recycling" to the extraction of high-value materials.

[0003] Currently, there are several technical routes for recycling photovoltaic modules, including physical methods, pyrolysis methods, and chemical methods. Physical methods are difficult to extract high-value metals economically and have low recovery rates. Chemical methods, based on pyrolysis and hydrometallurgy, aim to achieve high-purity extraction of silicon, silver, etc., but are limited by high energy consumption and potential secondary pollution risks. The core of the future industry lies in optimizing recycling technology; the need for more efficient, low-energy, and greener processing technologies is urgent, transforming millions of tons of "green pollution" into "urban minerals" supporting sustainable industrial development. Therefore, how to provide an efficient, low-energy, and green photovoltaic module recycling technology is the fundamental problem this invention aims to solve. Summary of the Invention

[0004] To provide a high-efficiency, low-energy-consumption, and green photovoltaic module recycling technology, this application provides a high-efficiency preparation method and equipment for photovoltaic module recycling, adopting the following technical solution:

[0005] In a first aspect, the present invention provides an efficient method for preparing recycled photovoltaic modules, comprising:

[0006] The photovoltaic modules are pre-treated, including cleaning, dust removal, junction box disassembly, aluminum frame removal, and edge adhesive removal.

[0007] Based on machine vision recognition, the pre-processed areas of the photovoltaic module are divided into cell areas and non-cell areas. Laser cutting is used to separate the EVA film in the cell areas and non-cell areas.

[0008] The first laser scanning method debonds and separates the battery cell from the glass, while the EVA film remains on the glass.

[0009] The detached battery cells are broken down and sorted; the glass is debonded using a second laser scan, and the glass and EVA film are recycled.

[0010] Optionally, when the photovoltaic module is a single-glass module, the method further includes:

[0011] After the photovoltaic module is pre-treated, the backsheet at the edge is warped and clamped by a third laser scan and a mechanical scraper. The backsheet is pulled up while the third laser scan is performed until the backsheet is completely peeled off and collected into a special collection device.

[0012] The third laser scanning process includes: dividing the scanning area into different partitions, and automatically switching the laser head to the corresponding preset power level when scanning different areas;

[0013] The process of separating the solar cell from the glass includes the separation of the front area of ​​the solar cell from the front glass.

[0014] Optionally, when the photovoltaic module is a double-glass module, the process of debonding and separating the solar cell from the glass includes the process of debonding and separating the front area of ​​the solar cell from the front glass and the process of debonding and separating the back area of ​​the solar cell from the back glass.

[0015] Optionally, the control strategy for laser cutting includes:

[0016] Based on machine vision, discrete point arrays of battery cell edges are extracted, and continuous parametric contour curves are generated by fitting. The radius of curvature of each point on the contour curve is calculated.

[0017] Establish a model relating the width of the laser heat-affected zone to the current scanning speed, radius of curvature, and average power;

[0018] Using the velocity sequence of each interpolation point along the entire contour as the decision variable, and taking the shortest total processing time and the minimum acceleration impact of adjacent points as the comprehensive optimization objective, forward-looking velocity planning is carried out, and the real-time output power is dynamically adjusted at the point of sudden change in curvature radius.

[0019] The intensity of the cutting plasma spectrum is collected in real time by a photodiode, and the laser power increment at the next interpolation point is finely adjusted in real time by a fuzzy PID controller.

[0020] Optionally, the control strategy for the first laser scanning includes:

[0021] Preset the target temperature, reference scanning speed, and reference power, and use a bow-shaped grating path for area scanning;

[0022] The average temperature of the laser-affected area is obtained in real time using an infrared thermal imager, and the temperature deviation and the rate of change of deviation are calculated.

[0023] Discretize the scanned region into a grid, calculate the total historical thermal influence on the current point of action, and calculate the feedforward power correction based on the total historical thermal influence.

[0024] A gain-dispatch PID controller is used. Based on the different ranges of the current temperature deviation and the rate of change of deviation, the corresponding proportional coefficient, integral coefficient and derivative coefficient are selected from multiple preset PID parameters to calculate the power regulation and base power.

[0025] The difference between the base power and the feedforward power correction is used as the total control power.

[0026] Optionally, the speed can be dynamically adjusted when the total control power exceeds the allowable power range;

[0027] If the real-time temperature exceeds the preset upper limit during the scanning process, the laser power output will be stopped immediately and a safety backoff will be initiated.

[0028] Optionally, when processing a double-glass module, the first laser scan is performed independently on the front area of ​​the cell and the front glass, and on the back area of ​​the cell and the back glass, respectively. The target temperature, PID parameter set and thermal diffusion characteristic radius of each are set independently according to the crosslinking degree, thickness and thermal conductivity of the corresponding EVA film.

[0029] Optionally, the control strategy for the second laser scanning includes:

[0030] The thickness distribution of the residual EVA film on the glass surface was obtained using a white light interferometer.

[0031] Based on the thickness distribution map, the processing area is divided into three levels: thin layer, medium layer, and thick layer, corresponding to three sets of preset laser power, scanning speed, and defocusing amount process parameters, respectively.

[0032] When the thickness of the thin layer is less than a first preset threshold, the first power, the first scanning speed, and the first defocusing amount are used.

[0033] When the thickness of the intermediate layer is between the first preset threshold and the second preset threshold, the second power, the second scanning speed, and the second defocus amount are used.

[0034] When the thickness of the thick layer is greater than the second preset threshold, the third power, the third scanning speed, and the third defocus amount are used.

[0035] Based on the thickness level of each region, the corresponding laser power, scanning speed, and defocusing amount process parameters are used to perform the scanning.

[0036] Optionally, when processing a double-glass module, the second laser scan is performed independently on the front glass and the back glass, and each independently obtains the thickness distribution map of the residual EVA film.

[0037] Secondly, the present invention provides a highly efficient preparation equipment for photovoltaic module recycling, wherein the equipment employs a highly efficient preparation method for photovoltaic module recycling as described in any of the above claims, comprising:

[0038] The loading unit is used to load photovoltaic modules in a stacked manner;

[0039] The cleaning and dust removal unit is used to clean and remove dust from photovoltaic modules.

[0040] The disassembly unit is used to disassemble the junction box, remove the aluminum frame, and remove the adhesive from the edges of the photovoltaic modules after cleaning and dust removal.

[0041] The laser cutting unit uses machine vision to identify the cell area and non-cell area of ​​the photovoltaic module after preprocessing, and uses laser cutting to separate the EVA film in the cell area and non-cell area.

[0042] The first laser scanning unit is used to de-adhere the battery cells from the glass, while the EVA film remains on the glass;

[0043] The second laser scanning unit is used to remove adhesive from the glass.

[0044] The cell recycling unit is used to break down and sort the detached cells.

[0045] In summary, this application includes at least one of the following beneficial technical effects:

[0046] I. This invention achieves efficient, green, and low-energy-consumption recycling of photovoltaic modules. Compared with physical methods, this technical solution can guarantee the recycling rate of photovoltaic modules and improve the comprehensive recycling rate of glass, silicon wafers, EVA, metals, etc. Compared with pyrolysis methods, this technical solution has lower energy consumption and no secondary pollutants such as waste gas and waste liquid are generated. Compared with chemical methods, this technical solution has no heavy pollution and lower overall investment. Therefore, the technical solution of this invention can provide an efficient and green technical path for the green circular economy of photovoltaic module recycling.

[0047] Second, the laser cutting control strategy in this invention can automatically perform power compensation and speed adjustment at the curvature abrupt changes in the edge contour of the battery cell, ensuring a consistent width of the heat-affected zone and avoiding overheating or incomplete cutting at corners. The first laser scanning process uses two-dimensional spatial thermal history feedforward compensation and gain scheduling PID control to model and feedforward correct the thermal accumulation in the scanned area, and dynamically switches control parameters according to temperature deviation, making the temperature field in the scanned area more uniform and effectively protecting the silver grid lines and the PN junction of the battery cell. The second laser scanning achieves precise differentiated processing, namely, low-power high-speed scanning for thin layers and high-power low-speed scanning for thick layers. This avoids the process defects of overheating in thin layers or incomplete removal in thick layers under uniform parameters. At the same time, refining from two zones to three zones further improves control accuracy and reduces the parameter abrupt change gradient between adjacent regions. Attached Figure Description

[0048] Figure 1This is a flowchart of an efficient preparation method for recycling photovoltaic modules according to the present invention;

[0049] Figure 2 This is a schematic diagram of the structure of a single-glass photovoltaic module in an embodiment of the present invention;

[0050] Figure 3 This is a flowchart of an efficient preparation method for recycling single-glass photovoltaic modules in this invention.

[0051] Figure 4 This is a schematic diagram of the battery cell area and the non-battery cell area in an embodiment of the present invention;

[0052] Figure 5 This is a schematic diagram of the structure of the double-glass module in an embodiment of the present invention;

[0053] Figure 6 This is a flowchart of an efficient preparation method for recycling double-glass photovoltaic modules in this embodiment of the invention. Detailed Implementation

[0054] The embodiments of this application are described in detail below, and examples of the embodiments are shown in the accompanying drawings.

[0055] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" refer to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0056] Please see Figure 1 This application discloses an efficient preparation method for recycling photovoltaic modules, comprising:

[0057] The photovoltaic modules are pre-treated, including cleaning, dust removal, junction box disassembly, aluminum frame removal, and edge adhesive removal.

[0058] Based on machine vision recognition, the pre-processed areas of the photovoltaic module are divided into cell areas and non-cell areas. Laser cutting is used to separate the EVA film in the cell areas and non-cell areas.

[0059] The first laser scanning method debonds and separates the battery cell from the glass, while the EVA film remains on the glass.

[0060] The detached battery cells are broken down and sorted; the glass is debonded using a second laser scan, and the glass and EVA film are recycled.

[0061] This invention achieves efficient, green, and low-energy-consumption recycling of photovoltaic modules. Compared with physical methods, this technical solution can guarantee the recycling rate of photovoltaic modules and improve the comprehensive recycling rate of glass, silicon wafers, EVA, metals, etc. Compared with pyrolysis methods, this technical solution has lower energy consumption and produces no secondary pollutants such as waste gas and waste liquid. Compared with chemical methods, this technical solution has no heavy pollution and lower overall investment. Therefore, the technical solution of this invention can provide an efficient and green technical path for the green circular economy of photovoltaic module recycling.

[0062] It should be noted that debonding and separation refers to the failure of the adhesive layer between the EVA film and the battery cell; debonding treatment refers to laser debonding of the EVA film remaining on the glass. Machine vision recognition is implemented using existing solutions and will not be described in further detail.

[0063] Example 1: Efficient Preparation Method for Recycling Single-Glass Photovoltaic Modules

[0064] Please see Figure 2-4 , Figure 2 This is a schematic diagram of a single-glass photovoltaic module. Figure 3 A flowchart illustrating an efficient preparation method for recycling single-glass photovoltaic modules. Figure 4 This diagram illustrates the relationship between the cell region and the non-cell region. The specific process of the efficient fabrication method for recycling single-glass photovoltaic modules includes:

[0065] S10. Pre-processing of single-glass photovoltaic modules: The pre-processed single-glass photovoltaic module products are stacked and fed with the back panel 12 facing up. They are fed by a six-axis robot to the cleaning and dust removal station for cleaning and dust removal. After cleaning, the single-glass photovoltaic module products are transferred by conveyor belt to the junction box disassembly station for disassembling the back junction box 10. Then, they are sent to the aluminum frame disassembly station to remove the aluminum frame and remove the adhesive from the edges.

[0066] S11. Single-glass photovoltaic module backsheet processing: The pre-treated single-glass photovoltaic module is conveyed by belt to the backsheet processing laser position and is adsorbed and fixed on the flat surface of the fixture. Then, the laser head performs a third laser scan processing. At the same time, the mechanical scraper structure cuts into the edge of the product, causing the backsheet at the edge to bend and clamp. Then, the laser head performs a third laser scan processing, pulling up the backsheet while scanning until it is completely peeled off. The backsheet is collected into a special collection device.

[0067] In the above steps, one or more laser heads can be set as needed; the specifications of the laser heads are adaptively set according to the specific cutting and scanning requirements. In this step, for backsheet peeling, a 1064nm infrared nanosecond laser is used. Its energy can be absorbed by the backsheet and instantly vaporized. Since the silicon wafer has a low absorption rate for this wavelength of laser, it can be completely peeled off. Since the backsheet processing requires physical assistance, the laser scanning process requires slightly lower precision. In this embodiment, the third laser scanning process adopts a partitioned fixed power method, including: dividing the scanning area into different partitions, including the edge area and the center area; obtaining the typical EVA state of this batch of single-glass photovoltaic modules based on experimental data; and obtaining the optimal power based on it. When the laser head is scanning in the edge area, the power is adjusted to 1.05 times the optimal power because of its fast heat dissipation; when the laser head is scanning in the center area, the power is adjusted to 0.95 times the optimal power because of its large heat accumulation.

[0068] By employing a zoned and graded power-adjusting strategy, the laser power is adaptively adjusted according to the differences in heat dissipation conditions in different areas. Higher power is used in the edge areas to compensate for heat loss, while lower power is used in the central areas to avoid heat accumulation. Combined with real-time temperature monitoring by an infrared thermal imager, the success rate and safety of backplate peeling are significantly improved.

[0069] It should be noted that the definition of the edge zone and the center zone is set according to the specific structural adaptability of the photovoltaic module.

[0070] S12. Identification and cutting of battery cell area and non-battery cell area: After the backplate is removed, the product is conveyed by belt to the cutting laser position. First, the battery cell area and non-battery cell area are identified by visual scanning. The edge of the battery cell area is taken as the positioning contour. Then, the cutting laser head performs cutting to separate the EVA adhesive in the battery cell area from the non-battery cell area, preparing for the next step of processing the EVA film covering the battery cell area.

[0071] The control strategy for laser cutting in the above steps includes:

[0072] Based on machine vision, discrete point lattice of battery cell edges is extracted, and a continuous parametric contour curve C(s) is generated by cubic B-spline curve fitting, where s is the actual path length from the point to the curve's starting point in mm. The radius of curvature of each point on the contour curve is then calculated. , .

[0073] Establish the width of the laser heat-affected zone With current scan speed radius of curvature and average power relational model Where A is the material absorption coefficient. For the thermal diffusivity of EVA material, The reference spot diameter is used; the finite difference implicit scheme is used to inversely calculate the required parameters. The theoretical upper bound of velocity under certain conditions , In this embodiment, to preset the maximum allowable width of the heat-affected zone, It is 100μm.

[0074] It should be noted that the material absorption coefficient and EVA thermal diffusivity were obtained from the material performance database; the reference spot diameter was obtained by looking up the reference parameters of the laser head.

[0075] The velocity sequence of each interpolation point along the entire contour The decision variables are set at the minimum total processing time and the minimum acceleration impact at adjacent points, which are the overall optimization objectives. M is the total number of interpolation points. The arc length of the contour curve from the (j-1)th interpolation point to the j-th interpolation point. , These are weighting coefficients, calibrated based on the maximum acceleration capability and contour accuracy requirements of the laser scanning device; The time interval required to move from the (j-1)th interpolation point to the jth interpolation point is given by the following constraint: , , The maximum allowable acceleration of the laser scanning device is given; the optimal velocity sequence is obtained by solving the comprehensive optimization objective.

[0076] It should be noted that the solution process for the comprehensive optimization objective is achieved through an enumeration method. By discretizing the continuous speed interval into N levels, all possible speed combinations are generated and the constraints are checked one by one. For each candidate speed sequence that passes all constraint checks, the function value T of the comprehensive optimization objective is calculated. The objective function values ​​T of all feasible candidate sequences are compared, and the sequence that minimizes T is selected as the optimal solution.

[0077] Furthermore, during the laser cutting process, the real-time output power is dynamically adjusted at points of abrupt change in the radius of curvature. The adjusted real-time output power is: , , These are the reference power and reference speed, set according to the parameter table provided by the equipment manufacturer, and a safe processing window is provided.

[0078] The intensity of the cutting plasma spectrum is collected in real time by photodiodes, and the laser power increment at the next interpolation point is finely adjusted in real time by a fuzzy PID controller, forming a closed-loop control that corrects while cutting.

[0079] Through the aforementioned laser cutting control strategy, power compensation and speed adjustment are automatically performed at the abrupt changes in curvature of the battery cell edge contour to ensure a consistent width of the heat-affected zone and avoid overheating at corners or incomplete cutting.

[0080] S13, EVA film debonding and detachment treatment (near the back panel side): After laser cutting, the product is conveyed by belt to the scanning laser position, and then the scanning laser head performs the first laser scanning treatment covering the EVA film in the battery cell area on the back, so that the EVA film debonds and detaches. The detached film is collected by a special collection device, and the original structure layer of the battery cell is preserved to the maximum extent, with almost no damage to the silver grid lines and solder ribbons.

[0081] S14. EVA film and cell debonding treatment (away from the back panel): After the EVA film on the back of the cell is treated, the product is transported to the next processing station by a six-axis robot. It is flipped so that the front glass is facing up and placed on a special adsorption fixture. Then, a laser head performs the first laser scan treatment on the EVA film covering the front cell area, causing the EVA film to debond from the cell. The debonded cells are collected by a special collection device for subsequent multi-stage crushing, electrostatic sorting, and eddy current sorting. The EVA film remains on the glass, preserving the original structure and integrity of the cell to the greatest extent possible, with almost no damage to the silver grid lines and solder ribbons.

[0082] In the above steps, the control strategy for the first laser scan includes:

[0083] Preset target temperature Reference scan speed and reference power A bow-shaped grating path is used for area scanning;

[0084] The average temperature T(K) of the laser-affected area is acquired in real time using an infrared thermal imager, and the temperature deviation is calculated. and the rate of change of deviation k represents the current sampling period, and k-1 represents the previous sampling period;

[0085] Discretize the scanned region into a grid and calculate the sum of historical thermal effects on the current point of action (x, y): ,in, The characteristic radius of thermal diffusion is determined based on the material and the laser pulse width. Let Q be the coordinates of the historical scan points, and Q be the number of points scanned; based on the total historical thermal influence... Calculate the feedforward power correction amount , The preset thermal accumulation influence coefficient is obtained based on the test calibration of EVA-glass.

[0086] A gain-controlled PID controller is used, based on the different ranges of the current temperature deviation and the rate of change of the deviation. The range of the current temperature deviation includes large deviations ( ), medium deviation ( ) and small deviations ( The range of deviation change rate includes positive change rate ( ), zero rate of change ( ) and negative rate of change ( Select the corresponding proportional coefficient from a set of preset PID parameters. Integral coefficient and differential coefficients , please refer to the following table for details:

[0087] big deviation Positive rate of change 6.0 0.2 0.5 big deviation Zero rate of change 5.5 0.5 0.5 big deviation negative rate of change 7.0 0.1 2.0 medium deviation Positive rate of change 3.5 0.5 1.0 medium deviation Zero rate of change 3.0 1.2 0.5 medium deviation negative rate of change 4.5 0.4 2.0 small deviation Positive rate of change 1.5 1.0 1.5 small deviation Zero rate of change 0.8 2.5 0.8 small deviation negative rate of change 2.0 1.5 2.5

[0088] Calculate power regulation and base power Where, when k=0, .

[0089] The difference between the base power and the feedforward power correction is used as the total control power. .

[0090] When the total control power exceeds the allowable power range, the speed is dynamically adjusted, and the adjusted speed is: , The speed adjustment coefficient is obtained from experimental calibration and is set to 0.2 mm / (s·W) in this embodiment. f(x) is a saturation function. When -1 < x ≤ 1, f(x) = x; when x > 1, f(x) = 1; when x ≤ -1, f(x) = -1. Through the above process, the speed can be limited to the preset speed range. After the speed changes, the power is synchronously compensated in reverse to maintain the continuity of the linear energy density. If the real-time temperature exceeds the preset upper limit during the scanning process, the laser power output is immediately stopped and the safety backoff is initiated.

[0091] The first laser scanning process uses two-dimensional spatial thermal history feedforward compensation and gain scheduling PID control to model and feedforward the thermal accumulation in the scanned area, and dynamically switches control parameters according to temperature deviation to make the temperature field in the scanned area more uniform, effectively protecting the silver grid lines and the PN junction of the solar cell.

[0092] S15. Glass and EVA film separation and recycling: After the glass products are processed and separated from the battery cells, they are transferred to the next station by a conveyor belt. A laser head performs a second laser scan to retain the EVA film covering the glass, so that the EVA film is debonded from the glass and the integrity of the glass is preserved to the maximum extent. It can be reused. The EVA film and glass are collected by a special collection device.

[0093] The control strategy for the second laser scan in the above steps includes:

[0094] The thickness distribution of residual EVA film on the glass surface was obtained using a white light interferometer. According to the thickness distribution map The processing area is divided into three levels: thin layer, medium layer, and thick layer, corresponding to three sets of preset laser power, scanning speed, and defocusing amount process parameters. When the thickness of the thin layer is less than the first preset threshold, the first power, first scanning speed, and first defocusing amount are used; when the thickness of the medium layer is between the first and second preset thresholds, the second power, second scanning speed, and second defocusing amount are used; when the thickness of the thick layer is greater than the second preset threshold, the third power, third scanning speed, and third defocusing amount are used. Please refer to the table below for the corresponding relationships in this embodiment:

[0095] thin layer χ < 10 μm 12W 1000mm / s +5mm Middle layer 10μm≤χ≤50μm 27W 600mm / s +2mm thick layer χ>50μm 39W 300mm / s 0mm

[0096] Based on the thickness grade of each region, after determining the corresponding power, scanning speed, and defocusing parameters in the table above, the laser head performs scanning according to these parameters. It should be noted that the parameters in the table above are based on the corresponding laser head calibration. The process parameters for different wavelengths and energy densities are different and need to be calibrated in advance.

[0097] By employing a second laser scanning control strategy, precise differentiated processing was achieved, namely, low-power high-speed scanning for thin layers and high-power low-speed scanning for thick layers. This avoided process defects such as overheating of thin layers or incomplete removal of thick layers under uniform parameters. At the same time, refining the control from two zones to three zones further improved control accuracy and reduced parameter abrupt gradients between adjacent regions.

[0098] Example 2: Efficient Preparation Method for Recycling Double-Glass Photovoltaic Modules

[0099] Please see Figure 4-6 , Figure 5 This is a schematic diagram of a double-glass module. Figure 6 A flowchart of an efficient preparation method for recycling double-glass photovoltaic modules includes:

[0100] S20. Pre-processing of double-glass photovoltaic modules: The pre-processed photovoltaic module products are stacked and fed with the junction box facing up. They are fed by a six-axis robot to the cleaning and dust removal station for cleaning. After cleaning, the photovoltaic module products are transferred by belt conveyor to the junction box removal station for disassembly of the back junction box. Then, they are sent to the aluminum frame removal station to remove the aluminum frame and remove the adhesive from the edges.

[0101] S21. Identification and Cutting of Cell and Non-Cell Areas: The product is conveyed by a belt to the cutting laser position and is adsorbed and fixed on the flat fixture surface. First, visual scanning determines the cell and non-cell areas. Figure 4 As shown, the edge of the battery cell area is taken as the positioning contour, and then the laser head cuts through the glass to separate the EVA adhesive in the battery cell area from the non-battery cell area.

[0102] The laser cutting control strategy in this embodiment is the same as that in Embodiment 1, and will not be described in detail.

[0103] S22, EVA film and battery cell debonding process (both sides): After laser cutting, the product is conveyed by belt to the scanning laser position, and then the laser head performs the first laser scanning process to debond the EVA adhesive on the back battery cell area from the glass, leaving the EVA film on the back glass; then the six-axis robot picks up the material and flips it over, and continues to perform the first laser scanning process on the front side to debond the EVA adhesive on the front battery cell area from the glass, leaving the EVA film on the front glass.

[0104] The control strategy for the first laser scan in this embodiment is the same as that in Embodiment 1, and will not be described in detail. It should be noted that the first laser scan is performed independently on the front area of ​​the battery cell and the front glass, and on the back area of ​​the battery cell and the back glass. The target temperature, PID parameter group and thermal diffusion characteristic radius of each are set independently according to the crosslinking degree, thickness and thermal conductivity of the corresponding EVA film.

[0105] S23. EVA film debonding and detachment treatment (both sides) and recycling: The detached battery cells are collected by a special collection device for subsequent multi-stage crushing, electrostatic sorting and eddy current sorting. The front and back glass are debonded separately. A laser head performs a second laser scan to retain the EVA film covering the glass, so that the EVA film is debonded from the glass and the integrity of the glass is preserved to the maximum extent. It can be reused. The EVA film and glass are collected by a special collection device.

[0106] The control strategy for the second laser scanning in this embodiment is the same as that in Embodiment 1, and will not be described in detail. It should be noted that the second laser scanning is performed independently on the front glass and the back glass, and each independently obtains the thickness distribution map of the residual EVA film.

[0107] In one embodiment, a high-efficiency preparation equipment for photovoltaic module recycling is also provided, comprising: a feeding unit for feeding photovoltaic modules in a stacked manner; a cleaning and dust removal unit for cleaning and dust removal of the photovoltaic modules; a disassembly unit for disassembling the junction box, removing the aluminum frame, and removing the edge adhesive from the cleaned and dust-removed photovoltaic modules; a laser cutting unit for separating the cell area and non-cell area of ​​the photovoltaic module based on machine vision recognition, and separating the EVA film in the cell area and non-cell area based on laser cutting; a first laser scanning unit for debonding the cells from the glass, leaving the EVA film on the glass; a second laser scanning unit for debonding the glass; and a cell recycling unit for breaking and sorting the detached cells.

[0108] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A highly efficient method for preparing recycled photovoltaic modules, characterized in that, include: The photovoltaic modules are pre-treated, including cleaning, dust removal, junction box disassembly, aluminum frame removal, and edge adhesive removal. Based on machine vision recognition, the pre-processed areas of the photovoltaic module are divided into cell areas and non-cell areas. Laser cutting is used to separate the EVA film in the cell areas and non-cell areas. The first laser scanning method debonds and separates the battery cell from the glass, while the EVA film remains on the glass. The detached battery cells are broken down and sorted; the glass is debonded using a second laser scan, and the glass and EVA film are recycled.

2. The efficient preparation method for recycling photovoltaic modules according to claim 1, characterized in that, When the photovoltaic module is a single-glass module, the method further includes: After the photovoltaic module is pre-treated, the backsheet at the edge is warped and clamped by a third laser scan and a mechanical scraper. The backsheet is pulled up while the third laser scan is performed until the backsheet is completely peeled off and collected into a special collection device. The third laser scanning process includes: dividing the scanning area into different partitions, and automatically switching the laser head to the corresponding preset power level when scanning different areas; The process of separating the solar cell from the glass includes the separation of the front area of ​​the solar cell from the front glass.

3. The efficient preparation method for recycling photovoltaic modules according to claim 1, characterized in that, When the photovoltaic module is a double-glass module, the process of debonding and separating the solar cell from the glass includes the process of debonding and separating the front area of ​​the solar cell from the front glass and the process of debonding and separating the back area of ​​the solar cell from the back glass.

4. The efficient preparation method for recycling photovoltaic modules according to claim 1, characterized in that, The control strategy for laser cutting includes: Based on machine vision, discrete point arrays of battery cell edges are extracted, and continuous parametric contour curves are generated by fitting. The radius of curvature of each point on the contour curve is calculated. Establish a model relating the width of the laser heat-affected zone to the current scanning speed, radius of curvature, and average power; Using the velocity sequence of each interpolation point along the entire contour as the decision variable, and taking the shortest total processing time and the minimum acceleration impact of adjacent points as the comprehensive optimization objective, forward-looking velocity planning is carried out, and the real-time output power is dynamically adjusted at the point of sudden change in curvature radius. The intensity of the cutting plasma spectrum is collected in real time by a photodiode, and the laser power increment at the next interpolation point is finely adjusted in real time by a fuzzy PID controller.

5. The efficient preparation method for recycling photovoltaic modules according to claim 1, characterized in that, The control strategy for the first laser scanning includes: Preset the target temperature, reference scanning speed, and reference power, and use a bow-shaped grating path for area scanning; The average temperature of the laser-affected area is obtained in real time using an infrared thermal imager, and the temperature deviation and the rate of change of deviation are calculated. Discretize the scanned region into a grid, calculate the total historical thermal influence on the current point of action, and calculate the feedforward power correction based on the total historical thermal influence. A gain-dispatch PID controller is used. Based on the different ranges of the current temperature deviation and the rate of change of deviation, the corresponding proportional coefficient, integral coefficient and derivative coefficient are selected from multiple preset PID parameters to calculate the power regulation and base power. The difference between the base power and the feedforward power correction is used as the total control power.

6. The efficient preparation method for recycling photovoltaic modules according to claim 5, characterized in that, When the total control power exceeds the allowable power range, the speed is dynamically adjusted; If the real-time temperature exceeds the preset upper limit during the scanning process, the laser power output will be stopped immediately and a safety backoff will be initiated.

7. The efficient preparation method for recycling photovoltaic modules according to claim 5, characterized in that, When processing double-glass modules, the first laser scan is performed independently on the front area of ​​the cell and the front glass, and on the back area of ​​the cell and the back glass. The target temperature, PID parameter set and thermal diffusion characteristic radius of each are set independently according to the crosslinking degree, thickness and thermal conductivity of the corresponding EVA film.

8. The efficient preparation method for recycling photovoltaic modules according to claim 1, characterized in that, The control strategy for the second laser scanning includes: The thickness distribution of the residual EVA film on the glass surface was obtained using a white light interferometer. Based on the thickness distribution map, the processing area is divided into three levels: thin layer, medium layer, and thick layer, corresponding to three sets of preset laser power, scanning speed, and defocusing amount process parameters, respectively. When the thickness of the thin layer is less than a first preset threshold, the first power, the first scanning speed, and the first defocusing amount are used. When the thickness of the intermediate layer is between the first preset threshold and the second preset threshold, the second power, the second scanning speed, and the second defocus amount are used. When the thickness of the thick layer is greater than the second preset threshold, the third power, the third scanning speed, and the third defocus amount are used. Based on the thickness level of each region, the corresponding laser power, scanning speed, and defocusing amount process parameters are used to perform the scanning.

9. The efficient preparation method for recycling photovoltaic modules according to claim 8, characterized in that, When processing double-glass modules, the second laser scan is performed independently on the front glass and the back glass, and each independently obtains the thickness distribution map of the residual EVA film.

10. A high-efficiency preparation equipment for photovoltaic module recycling, characterized in that, The equipment employs a highly efficient preparation method for photovoltaic module recycling as described in any one of claims 1-9, comprising: The loading unit is used to load photovoltaic modules in a stacked manner; The cleaning and dust removal unit is used to clean and remove dust from photovoltaic modules. The disassembly unit is used to disassemble the junction box, remove the aluminum frame, and remove the adhesive from the edges of the photovoltaic modules after cleaning and dust removal. The laser cutting unit uses machine vision to identify the pre-processed cell area and non-cell area of ​​the photovoltaic module, and uses laser cutting to separate the EVA film in the cell area and the non-cell area. The first laser scanning unit is used to de-adhere the battery cells from the glass, while the EVA film remains on the glass; The second laser scanning unit is used to remove adhesive from the glass. The cell recycling unit is used to break down and sort the detached cells.

Images