Method and device for processing solar modules

Abstract

The invention relates to a method for processing solar modules by means of a recycling installation, the method comprising the following steps: detecting the solar module by means of at least one sensor, so that the at least one sensor sends measurement data to an electrical controller, wherein the measurement data contains information about the solar module, evaluating the measurement data and determining operating parameters for the recycling installation and processing the solar module in the recycling installation, which is operated using the determined operating parameters.

Description

[0001] Method and device for processing solar modules

[0002] The invention relates to a method for processing solar modules by means of a recycling plant and to a device for carrying out such a method.

[0003] Solar modules are being used in increasing numbers in various designs to generate electricity from sunlight. These solar modules can be installed in small numbers on private roofs, such as residential buildings, to at least partially cover the electricity needs of the house on which the solar modules are mounted. Such decentralized energy supplies are being used in increasing numbers, also for the decentralized charging of electric vehicles, for example. However, solar modules are also being used in large systems on otherwise agricultural land to generate commercial electricity and feed it into the public power grid.

[0004] The problem is that solar modules only have a limited lifespan. Expensive raw materials are used in their production. For example, most solar modules have electrical conductors made of silver. For this reason alone, there is a need for a process to recycle these raw materials and make them available for reuse. In addition, the increasing number of solar modules that have reached the end of their lifespan and are therefore discarded creates a lot of waste that should be recycled or processed, especially given the environmental compatibility of power generation, which is what solar modules and the generation of electricity from sunlight stand for. A wide variety of different types of solar modules are known from the state of the art. However, some elements are contained in most of the known solar modules.Solar modules typically have a base body on which electrical conductors or other metal components are arranged. This can be made of silicon or glass. Solar modules also typically have a cover layer that defines the solar module's outer surface and is usually made of glass or another material that is at least partially, but preferably completely, transparent to visible light.

[0005] Different solar modules must be recycled in different ways to access the valuable raw materials and make them available for further use. Different processes are therefore known from various prior art documents. For solar modules in which metal components are arranged on a glass substrate, JP 2014 / 054593 A, for example, proposes a process in which these components are removed mechanically.

[0006] The invention is based on the object of simplifying the method for processing solar modules and of being able to process a larger number of differently constructed solar modules.

[0007] The invention solves the problem by a method for processing solar modules using a recycling plant, the method comprising the following steps:

[0008] - detecting the solar module by means of at least one sensor, so that the at least one sensor sends measurement data to an electrical control system, wherein the measurement data contains information about the solar module,

[0009] Evaluating the measurement data and determining operating parameters for the recycling plant and processing the solar module in the recycling plant, which is operated with the determined operating parameters.

[0010] In the method according to the invention, the solar module to be processed is detected by means of a sensor. The solar module can be detected completely or partially; the important thing is only that the measurement data obtained contain information about the solar module. The measurement data sent from the sensor to the electrical control unit contain information about the solar module. This information includes, for example, geometric dimensions and / or the weight of the solar module or one or more parts of the solar module, for example individual layers. Information about transmission properties and / or materials from which the solar module is at least partially made can also be included in the information.Additionally or alternatively, the information may also include a type designation, manufacturer name, logo, serial number and / or series, a barcode, or QR code, so that the type of solar module is identifiable enough to determine the operating parameters. For this purpose, it is advantageous if the solar module can be clearly identified. However, in many cases, it is sufficient to determine some parameters or properties of the solar module, or, for example, a series or classification of the solar module.

[0011] Measurement data refers in particular to all data that can be recorded and transmitted by a sensor, including in particular image data and the information contained therein.

[0012] The electrical control unit is preferably an electronic data processing device capable of evaluating the measurement data transmitted to it by the sensor and, based on the evaluated measurement data and / or the information extracted therefrom about the solar module, determining operating parameters that are used during subsequent processing of the solar module to operate the recycling plant. Preferably, the at least one sensor comprises at least one optical sensor, in particular at least one optical camera and / or a barcode scanner, wherein the measurement data is preferably digital image data. Alternatively or additionally, the at least one sensor comprises an acoustic sensor, which, for example, comprises an ultrasonic sensor and preferably an ultrasonic transmitter.Alternatively or additionally, the at least one sensor comprises at least one distance sensor, at least one scale, at least one layer thickness sensor and / or a system for performing laser-induced plasma spectroscopy (Laser Induced Breakdown Spectroscopy LIBS).

[0013] Particularly preferably, the measurement data are evaluated by image recognition software. The image recognition software is executed in the electrical control system and evaluates the measurement data transmitted by the at least one optical sensor. Advantageously, the measurement data from the electrical control system are compared with reference data stored in an electronic database.

[0014] Particularly preferably, the electrical control unit is capable of uniquely determining the type of solar module from the measurement data. This is the case, for example, when the image recognition software recognizes a type designation and / or a serial number in the measurement data, i.e. the digital image data. The type designation and / or the serial number do not necessarily have to be in the form of letters and / or numbers, but can also be present and recognized in a purely machine-readable form, for example in the form of a barcode or a QR code. The electrical control unit is preferably configured to access an electronic data storage device in which information about the various types of solar modules is stored in electronic form in a readable manner for the electrical control unit.Preferably, the electronic data storage device contains a database in which the respective operating parameters are stored for the different types of solar modules that can be processed. The electrical control system is preferably configured to compare a detected type of solar module with the entries in the database and thus read out the optimal operating parameters stored in the database for this type of solar module.

[0015] The electrical control sends control commands to the recycling plant which contain the operating parameters in a form that is understandable for the recycling plant, so that the recycling plant is operated with the determined operating parameters for the solar module to be processed.

[0016] In addition to the type of solar module, the measurement data can also contain information about individual components and layers of the solar module. This concerns, for example, the geometric dimensions, i.e. the spatial extent, of the different layers. For example, information about the size and / or thickness of a glass layer, e.g. a cover layer, and / or information about the refractive index and / or the reflection coefficient of the glass used and / or information about the composition of the glass can be contained in the measurement data and evaluated by the electrical control system. In this case, the electrical control system is preferably configured to access an electronic database in an electronic data storage device in order to determine the required operating parameters from the evaluated measurement data and the information extracted from it.

[0017] Advantageously, the solar module has a base body with a top surface on which metallic conductor tracks are arranged. The solar module also has a cover layer, which is attached to the top of the base body by means of an adhesive layer. During processing of the solar module, the adhesive layer is heated so that it at least partially, but preferably completely, loses its adhesive effect. The cover layer is then removed from the base body using a tool. The conductor tracks are then mechanically removed, and the removed material is collected.

[0018] The operating parameters preferably contain information about how long, in what way, how quickly and / or to what temperature the adhesive layer is heated and / or whether the entire adhesive layer or which part of the adhesive layer is heated. Preferably, the adhesive layer is heated by means of infrared radiation and / or magnetic induction and / or by means of microwave radiation. Preferably, the recycling plant has a separate heat source for several of these options, preferably for all of these options. In this case, which of these heat sources is used is included in the operating parameters. Preferably, the recycling plant has a plurality of heat sources. These can each enable different heating options or enable the same heating option. For example, several heat sources of one type, for example several infrared radiation sources, can be present.The operating parameters preferably contain information about which heat sources are used to heat the adhesive layer or part of the adhesive layer. This is useful, for example, if the heat sources are configured to heat a spatial area larger than the top of the solar module.

[0019] The heating preferably takes place at a temperature of more than 180 °C, preferably more than 200 °C, particularly preferably more than 230 °C and less than 400 °C, preferably less than 350 °C, particularly preferably less than 280 °C. Which temperature is used is preferably included in the operating parameters.

[0020] Particularly when using infrared or microwave radiation, it is advantageous to apply the radiation through the cover layer, which is preferably at least partially, but preferably completely transparent to the respective type of radiation. Infrared radiation used for this purpose preferably has a wavelength of 1000 to 4000 nm, more preferably 1000 to 2000 nm. Which wavelength is used is preferably included in the operating parameters. If microwave radiation is used, it preferably has a frequency between 2.4 GHz and 2.5 GHz, preferably 2.45 GHz. Alternatively, the microwave radiation has a frequency of 5.8 GHz. Heating by means of magnetic induction uses alternating magnetic fields whose frequency is preferably between 1 kHz and 500 kHz. A usable frequency range is referred to as the low-frequency range and includes frequencies between 1 kHz and 7 kHz.Another frequency range is called the mid-frequency range and includes frequencies between 8 kHz and 40 kHz. The high-frequency range includes frequencies between 60 kHz and 500 kHz. The frequency used is preferably between 25 kHz and 300 kHz, and particularly preferably between 25 kHz and 100 kHz.

[0021] The operating parameters preferably include which tool is used to remove the top layer, preferably whether a spatula, a scraper, a knife, a blade, and / or a wire and / or another tool is used. Particularly preferably, the operating parameters include which working parameters are to be used. The working parameters contain, for example, information about an angle of attack and / or a contact pressure of the tool.

[0022] In a preferred embodiment, the operating parameters include the removal method by which the conductor tracks are removed. In particular, the operating parameters include whether this is done by brushing, milling, planing, shaping, scraping, chiseling, reaming, blasting, and / or grinding. Particularly preferably, the operating parameters include process parameters of the removal method. The process parameters include, for example, information about the angle of attack and / or contact pressure of the tool, the rotation speed of brushes and / or grinding elements, or the forces or impact frequencies used.

[0023] The operating parameters preferably include whether the cover layer is damaged before removal. If this is the case, the operating parameters preferably also include whether the cover layer is damaged by means of a spatula, a putty knife, a knife and / or a wire and / or another tool. Preferably, in the method, the adhesive layer is heated to an adhesive layer temperature and the underside of the base body is cooled to a underside temperature. By heating the adhesive layer, it is possible to remove the cover layer from the rest of the layer element. The cover layer is preferably a glass layer which is particularly preferably completely transparent to visible light. By heating the adhesive layer, the adhesive force of the adhesive layer decreases and the cover layer can be removed.The heat introduced into the adhesive layer spreads within the layered element and gradually heats other layers and elements of the layered element. A plastic layer, such as polyvinyl fluoride (PVF), is often arranged on the underside of the base body. The material of this plastic layer is generally less heat-resistant than the base body, the cover layer, and especially the adhesive layer. The heat introduced to heat the adhesive layer also heats the plastic layer, which can decompose it, releasing harmful and hazardous gases. According to the invention, this is prevented by cooling the underside of the base body to a lower temperature.

[0024] For the purposes of the present invention, processing a layered element includes, for example, at least partially disassembling the layered element. In a preferred embodiment, this occurs by completely or partially removing the cover layer from the base body. This preferably occurs without damaging or destroying the cover layer in the process. However, this is not necessarily the case. Even if the cover layer is damaged or destroyed during the complete or partial removal from the base body and / or before the complete or partial removal from the base body, this constitutes "processing" within the meaning of the present invention.

[0025] This does not mean that the underside is cooled to a temperature below room temperature during the process. Before the process begins, the underside of the base body of the layered element has a temperature significantly below the target underside temperature. It simply means that heat is dissipated from the underside of the base body to reach and, preferably, maintain the underside temperature. The underside temperature is lower than the bond layer temperature.

[0026] In order to cool the underside of the base body to a bottom temperature, a cooling device is provided through which heat is dissipated from the underside of the base body.

[0027] One difficulty overcome by the method in these embodiments is that the conductor tracks of the layer elements, for example of solar modules made from the valuable raw material, are not accessible from the outside. Although they are located on the upper side of the base body, they are covered by the cover layer, which is secured by the at least one adhesive layer. By heating the adhesive layer, its adhesive effect is reduced, so that the cover layer and the base body can then be removed from each other. The conductor tracks arranged on the upper side of the base body are then accessible. They are then removed from the base body by mechanical ablation, and the material removed in this process is collected.

[0028] Preferably, the operating parameters include how long, in what manner, how fast and / or to what temperature the underside is cooled and / or whether the entire underside or which part of the underside is cooled.

[0029] The layer element is preferably a solar module, wherein the layer element preferably has metallic conductor tracks, which are particularly preferably arranged on the upper side of the base body and are covered by the cover layer.

[0030] The adhesive layer temperature is preferably at least 180°C, preferably at least 200°C, more preferably at least 230°C and at most 400°C, preferably at most 350°C, most preferably at most 280°C. This is particularly advantageous when the adhesive layer is a layer made of or containing ethylene vinyl acetate (EVA). The adhesive layer temperature is preferably selected such that pyrolysis of the adhesive layer, which can release toxic and environmentally harmful gases, does not occur. This is avoided at a temperature below 400°C. At a temperature of more than 180°C, preferably more than 200°C, acetic acid is released in an EVA adhesive layer, forming a lubricating film between the layers connected by the adhesive layer. As a result, the adhesive forces exerted by the adhesive layer decrease, and the two elements connected to one another can be separated.Preferably, therefore, at least one EVA film is used as the adhesive layer.

[0031] Preferably, the bottom temperature is at most 150°C, preferably at most 110°C, particularly preferably at most 100°C. The lower this temperature, the lower the effects of the heat on layers arranged on the underside of the base body.

[0032] The base body preferably has a structure composed of several layers arranged next to one another. The underside of the base body forms the underside of the layer element that is processed by the methods described here. The base body has, for example, a substrate that is preferably made of silicon, particularly preferably consists of silicon, and has a charge-doped zone and a hole-doped zone. The metallic conductor tracks are arranged on the top side of this substrate, which forms the top side of the base body. The underside of the substrate does not necessarily have to form the underside of the layer element. Further layers, for example the plastic layer already mentioned, can be arranged on the underside of the substrate. The underside of the base body preferably forms the underside of the layer element.

[0033] The invention also solves the problem by a device for

[0034] Processing solar modules, wherein the device comprises at least one sensor for detecting the solar module, a recycling system and an electrical control system which is configured to carry out one of the methods described here.

[0035] Preferably, the device comprises a heating device for heating the adhesive layer of a layer element to the adhesive layer temperature and a cooling device for cooling the underside of the base body of the layer element to the underside temperature.

[0036] The device preferably has a holding device with which the layer element that is processed by means of the device is held. The device preferably has a work table for supporting the layer element, wherein the cooling device is preferably arranged within the work table. In a particularly preferred embodiment, the work table has a support surface on which the layer element rests while the method is being carried out. This support surface can preferably be cooled by the cooling device. The holding device with which the layer element is held is, for example, a pulling device for exerting a pulling force. This can, for example, have at least one negative pressure element, for example a suction element. The layer element is, for example, positioned on openings within the support surface, which are closed by the layer element.By applying a negative pressure or a suction force to the closed openings, a suction force and thus a tensile force is exerted on the layer element, which holds it to the support surface.

[0037] Alternatively or additionally, the holding device has a pressure device for exerting a compressive force. This compressive force presses the layer element against the support surface. The pressure device preferably has at least one, preferably several, hold-down devices. These are preferably movable relative to the support surface. The hold-down devices are preferably removed from the support surface in order to arrange a layer element to be processed on the support surface. The hold-down devices are then lowered until they come into contact with the layer element and can exert a compressive force on the layer element.

[0038] The cooling device preferably has at least one fluid channel through which a cooling medium can be conducted. The cooling medium is, for example, a cooling liquid, such as water. The cooling device preferably has a pump that moves the cooling medium through the fluid channel. If the fluid channel is located within the work table, it is advantageous if it is made of a material with high thermal conductivity, for example, a metal such as aluminum or steel.

[0039] Preferably, the at least one cooling channel is located as close as possible to the actual support surface of the work table, for example, at most 15 cm, preferably at most 10 cm, and particularly preferably at most 5 cm from the support surface. The material of the work table, at least the material of the work table located between the at least one cooling channel and the support surface, preferably has a high thermal conductivity. The material is preferably a metal, for example, aluminum or steel.

[0040] Alternatively or additionally, the cooling device has at least one fan through which air can be directed to the underside of the layer element. The fan can, for example, be designed in the form of one or more fans arranged and oriented to move air toward the underside of the layer element.

[0041] The device preferably has a first temperature sensor for detecting the adhesive layer temperature and / or a second temperature sensor for detecting the underside temperature. The first temperature sensor and / or the second temperature sensor preferably has a pyrometer, by means of which the occurring temperatures can be detected, preferably without contact. The device preferably has an electrical control system, particularly preferably an electronic data processing device, which is configured to control the heating device and / or the cooling device depending on the detected adhesive layer temperature and / or the detected underside temperature. For this purpose, the respectively detected temperature is compared with a target temperature stored in an electronic data memory. The target temperature can also be a temperature range within which the detected temperature should lie.The electrical control is configured to increase the heating device's power and / or the heating duration if the detected adhesive layer temperature is deemed too low after comparison with a stored target temperature. Preferably, the electrical control is alternatively or additionally configured to increase the cooling device's power and / or the cooling duration if the detected underside temperature is deemed too high after comparison with a stored target temperature.

Claims

Patent claims 1. A method for processing solar modules using a recycling plant, the method comprising the following steps: - Detecting the solar module by means of at least one sensor, such that the at least one sensor sends measurement data to an electrical control, wherein the measurement data contains information about the solar module, - Evaluating the measurement data and determining operating parameters for the recycling plant and - Processing the solar module in the recycling plant, which is operated with the determined operating parameters.

2. Method according to claim 1, characterized in that the at least one sensor comprises at least one optical sensor, in particular at least one optical camera, wherein the measurement data are preferably digital image data.

3. Method according to claim 2, characterized in that the measurement data are evaluated by an image recognition software which compares the measurement data with reference data stored in an electronic database.

4. Method according to one of the preceding claims, characterized in that the solar module has a base body with a top surface on which metallic conductor tracks are arranged, and a cover layer which is arranged on the top surface of the base body by means of an adhesive layer, wherein during processing of the solar module the adhesive layer is heated, then the cover layer is removed from the base body by means of a tool and then the conductor tracks are mechanically removed, wherein the removed material is collected.

5. Method according to claim 4, characterized in that the operating parameters include how long, in what way, how quickly and / or to what temperature the adhesive layer is heated and / or whether the entire adhesive layer or which part of the adhesive layer is heated.

6. Method according to claim 4 or 5, characterized in that the operating parameters include which tool is used to remove the top layer, preferably whether a spatula, a putty knife, a knife, a blade and / or a wire and / or another tool is used.

7. Method according to claim 6, characterized in that the operating parameters include working parameters of the tool.

8. Method according to one of claims 4 to 7, characterized in that the operating parameters include the removal method by which the conductor tracks are removed, in particular whether this is done by brushing, milling, planing, broaching, scraping, chiseling, reaming, blasting and / or grinding.

9. Method according to claim 8, characterized in that the operating parameters include process parameters of the removal process.

10. Method according to any one of claims 4 to 9, characterized in that operating parameters include whether the top layer is damaged before removal, and preferably whether this is done by means of a spatula, a putty knife, a knife and / or a wire and / or another tool.

11. Device for processing solar modules, wherein the device comprises at least one sensor for detecting the solar module, a recycling system and an electrical control system configured to carry out a method according to one of the preceding claims.