Apparatus and method for sanitising rear faces of solar modules

Abstract

The present invention relates to an apparatus (100) for sanitising rear faces of solar modules, which comprises, one after the other in a treatment direction (A), a washing device (1), a drying device (3), a solar module rear face coating device (8), and a coating treatment device (14). The invention also relates to a method for sanitising rear faces of solar modules, in which the solar modules are washed, dried after washing, coated on the rear face thereof in a coating process after drying, and the applied coating is dried and polymerised. According to the invention, the drying device is designed at least in part as a paternoster lift or the drying of the washed solar modules takes place at least in part in a paternoster lift in which the solar modules are moved up and down while horizontal.

Description

[0001] Device and method for renovating the backs of solar modules

[0002] The present invention relates to a device for renovating the backs of solar modules, which comprises, in a treatment direction, a washing device, a drying device, a solar module backside coating device, and a coating treatment device. The invention further relates to a method for renovating the backs of solar modules, in which the solar modules are washed, dried after washing, coated on their backside in a coating process after drying, and the applied coating is dried and polymerized.

[0003] Photovoltaic systems consist of solar modules. Solar modules convert sunlight into electrical energy. Rigid solar modules typically consist of silicon-based solar cells, which are typically laminated and hermetically encapsulated using encapsulation material, either between two glass plates or between a glass plate and a backsheet.

[0004] Currently, solar modules in the form of glass-foil modules are being used, particularly by homeowners and ground-mounted systems. These modules feature a glass layer on top, an embedding film to protect the solar cells, solar cells, solder connectors for connecting the solar cells, a backsheet, a junction box, and, if required, an aluminum frame and frame sealing tape for the stability and durability of the solar module.

[0005] By using a backsheet instead of a glass plate, glass-on-glass modules are more cost-effective and lighter than glass-on-glass modules. Since the backsheet is used on the side of the solar module facing away from the light, which is less exposed to environmental influences, it is generally legitimate to use the less robust film on this side.

[0006] Polyvinyl fluoride films are commonly used as backsheet films. Polyvinyl fluoride films are highly tear-resistant, UV-resistant, and also form a moisture barrier. However, solar module backsheets are also available made of polyamide or polyester (PET).

[0007] Especially with backsheets made of polyamide or polyester, damage becomes apparent after some time of use, manifesting itself in, for example, embrittlement, cracks, edge seals destroyed by water penetration, delamination, yellowing, blistering, and breakage. The consequences are massive module damage and performance losses in photovoltaic systems, including the problem of poor operational reliability and the risk of fire.

[0008] From the document DE 10 2017 125 226 A1 a method for repairing a solar module is known, in which the solar module is first cleaned and then an adhesive paste or liquid is applied to a partially or completely damaged rear encapsulation element of the solar module and a covering layer is applied to this, wherein the adhesive paste or liquid is subsequently cured.

[0009] A generic method for sealing the back of such solar modules during a repair is known from the publication DE 10 2020 002 093 A1. The solar modules undergo several process steps. First, the solar modules are cleaned with water. The water remaining on the solar modules is then wiped off and then blown off using an air curtain. To remove any remaining water from the solar modules, they are then irradiated with pulsed infrared radiation. The back of the cleaned and dried solar modules is then sprayed with a plastic sealing material, which is subsequently dried and polymerized using pulsed infrared radiation.

[0010] Solar modules treated in this way are then fully usable again. However, it has been shown that despite the intensive cleaning and drying steps and the careful coating process, inclusions can occur in the coating, which can lead to the coating peeling off.

[0011] It is therefore the object of the present invention to improve the generic method in such a way that such detachment effects can be avoided. Furthermore, a suitable device is to be provided on which a corresponding method can be carried out with high efficiency.

[0012] The object is achieved, on the one hand, by a device for renovating the backs of solar modules, which device has, in a treatment direction, a washing device, a drying device, a solar module back-side coating device and a coating treatment device, in which the drying device is at least partially designed as a paternoster.

[0013] In the paternoster, a plurality of solar modules arranged on individual levels of the paternoster can be moved past at least one drying module of the drying device, which can direct an air and / or heat flow onto the solar modules, drying both the front and back of the solar modules. This is possible in the paternoster without having to turn the solar modules.

[0014] The device according to the invention works particularly effectively when the washing device has washing elements and washing nozzles arranged above and below a solar module guideway. The washing elements and washing nozzles arranged above and below the solar module guideway allow the solar modules to be effectively cleaned simultaneously from both sides. The washing elements are, for example, roller-shaped brushes. The washing nozzles are preferably arranged in the form of at least one row of nozzles aligned transversely to the treatment direction. The nozzles can be integrated into the washing elements. The washing elements and also the washing nozzles are designed and operated with operating parameters, such as brush rotation speed and / or water pressure, that prevent further damage to the backs of the solar modules.

[0015] It is particularly advantageous if the washing facility is a closed system with a closed water circuit.

[0016] The device can incorporate a reverse osmosis unit integrated into the closed water circuit, making it particularly environmentally friendly. Preferably, the solar modules in the paternoster are mounted on frame-shaped solar module supports, allowing the entire surface of the front and back of the solar modules to be dried simultaneously.

[0017] Drying of the solar modules in the paternoster is particularly intensive when it is located in a paternoster cabinet, i.e., when it is enclosed in a housing that is heatable or heated. For this purpose, at least one heating element, such as several heating guns, is arranged in and / or on the paternoster cabinet.

[0018] The drying in the drying device is further intensified if at least one dehumidifier is arranged in the paternoster cabinet.

[0019] In order to effectively carry out a back coating of the cleaned and dried solar modules, it is advantageous if a solar module turning device is arranged in the treatment direction between the drying device and the solar module back coating device.

[0020] In an advantageous embodiment of the device according to the invention, an infrared pretreatment device is arranged between the solar module turning device and the solar module backside coating device. The infrared pretreatment device is preferably used for deep drying the backsides of the solar modules prior to backside coating, but can also be used to preheat the solar module backsides prior to backside coating. Both have a beneficial effect on the adhesion and durability of the coating applied to the backsides of the solar modules during backside coating.

[0021] It has been shown that solar modules can have cracks in their backsheet that cannot be sufficiently repaired with a simple spray coating. In an advantageous development of the device according to the invention, the solar module backsheet coating device therefore has, in addition to a spraying or rolling device, an optical crack detection device and a crack filling and / or filling device. If a crack is detected by the optical crack detection device, which can be a camera, for example, it can be automatically filled with a filler using the crack filling and / or filling device. In this way, all cracks in the backsheet can be filled first, and then the entire backside of the solar module can be sprayed with a plastic coating compound using the spraying or rolling device, or the plastic coating can be rolled on.For this purpose, the solar module backside coating device is preferably mounted on a robot.

[0022] In order to achieve a high-quality back coating with the spraying or rolling device of the solar module back coating device, it is advantageous if an extraction air curtain is formed on the side of the solar module back coating device.

[0023] In an advantageous embodiment of the present invention, the coating treatment device is also designed as a paternoster. This achieves particularly effective curing of the coating material applied to the backs of the solar modules.

[0024] Preferably, the coating treatment device is an infrared coating treatment device. However, another heat and / or radiation treatment device, such as a UV radiation treatment device, can also be used for the coating treatment.

[0025] In principle, the coating treatment device can also be or include a cooling device. This can be advantageous, for example, if the coating applied to the solar modules is initially hot.

[0026] In an advantageous embodiment of the device according to the invention, the drying device comprises a vacuum chamber and / or a vacuum chamber is arranged downstream of the coating treatment device in the treatment direction. This prevents the formation of bubbles in the coating.

[0027] In a likewise advantageous embodiment of the invention, a solar module front-side nanocoating device is arranged downstream of the coating treatment device in the treatment direction. This allows the solar module front to be additionally protected. The object is further achieved by a method for renovating the backs of solar modules, in which the solar modules are washed, dried after washing, coated on their backs in a coating process after drying, and the applied coating is dried and polymerized. The drying of the washed solar modules is carried out at least partially in a paternoster in which the solar modules are moved up and down while lying down.

[0028] This procedure allows a large portion of the water applied during the previous washing process to be removed from the solar modules, thus minimizing the risk of water residues, particularly on the back of the solar modules, leading to unwanted water-drying spots, to which a subsequent coating will not adhere or only insufficiently. Due to the up and down movement of the solar modules in the paternoster, almost all areas on the front and back of the solar modules can be effectively dried by the air and / or heat flow emanating from at least one drying module of the drying system.

[0029] The method according to the invention can be carried out particularly effectively if the solar modules are washed on both sides simultaneously.

[0030] It is particularly advantageous if the water used to wash the solar modules is kept in a closed water circuit.

[0031] The process is particularly environmentally friendly if the water used for washing is purified in a reverse osmosis unit integrated into the water cycle.

[0032] The drying effect of the paternoster can be further enhanced if the paternoster is located in a paternoster cabinet that is heated.

[0033] Drying is further intensified if the paternoster cabinet is dehumidified. To ensure easy coating of the back of the solar modules, it is advantageous to turn the solar modules, which have been transported horizontally, after drying and before coating, with their backs facing up.

[0034] Particularly good adhesion and stability of the coating subsequently applied to the back of the solar module is achieved if at least the back of the solar modules is heated and / or deep dried by infrared radiation after turning and before coating.

[0035] The quality of the refurbished solar modules can be significantly improved if, after drying and before coating, the backs of the solar modules are inspected for cracks using an optical crack detection device.

[0036] If cracks are detected by the crack detection device, which can be a camera, for example, it is advisable not to simply spray the back of these solar modules with a coating, but to fill the cracks beforehand. Accordingly, in an advantageous embodiment of the method according to the invention, cracks detected by the crack detection device are filled and / or filled in a controlled manner by a crack filling and / or filling device.

[0037] The spray coating of the back of the solar module is particularly homogeneous and without particle inclusions if air is extracted during the spray coating by means of an air extraction curtain arranged to the side of a conveyor device on which the solar modules lie during the spray coating.

[0038] Preferably, the coated solar modules are moved up and down in a paternoster while the coating dries and polymerizes. This paternoster can be the same paternoster used to dry the washed solar modules, or a second paternoster. In such a paternoster, the curing of the coating compound takes place very effectively.

[0039] Preferably, the coating is dried and polymerized by infrared treatment, preferably by treatment with pulsed infrared radiation. However, the coated solar modules can also be treated alternatively or additionally with other radiation, such as UV radiation, and / or with heat to dry and polymerize the coating.

[0040] If the coating applied to the solar modules is hot, drying of the coating can also be achieved by cooling the coating.

[0041] In an advantageous embodiment of the method according to the invention, the solar modules are dried and / or the coating is dried and / or polymerized in a vacuum. This can prevent blistering in the coating.

[0042] It is also advantageous if a nanocoating is applied to the front of the solar module after the coating on the back of the solar module has been dried and polymerized.

[0043] An automatic incoming goods inspection can be carried out before washing or after drying the solar modules.

[0044] Preferably, in the method according to the invention, the solar modules are automatically placed on and removed from a conveyor device of the device according to the invention.

[0045] It is particularly advantageous to use a hydrophilic coating material for the back of solar modules. This material absorbs and traps water before drying and polymerizing. This prevents this water from causing blistering.

[0046] A preferred embodiment of the device according to the invention and the method according to the invention is explained in more detail below with reference to Figure 1.

[0047] Figure 1 shows a schematic plan view of a possible embodiment of a device 100 according to the invention for renovating the backs of solar modules. The process steps of the device 100 also clearly illustrate the sequence of one embodiment of the method according to the invention.

[0048] The device 100 is a system that can continuously renovate the back of a plurality of solar modules, the backs of which have a backsheet. The device 100 is typically installed in a factory and is therefore not intended for on-site renovating of solar modules.

[0049] The device 100 has process modules arranged one after the other in a treatment direction A, which are preferably connected to one another by means of automatic conveying mechanisms.

[0050] A process module located at an initial area of ​​the device 100 is a washing device 1. An automatic solar module test (not shown here) and, if appropriate, a solar module anonymization can be provided upstream of the washing device 1.

[0051] The solar modules to be refurbished are washed on or in the washing device 1. Water is used to rinse the solar modules. In the embodiment shown, the solar modules lie with their front sides facing sunlight during use, facing upwards on conveyor rollers 16 spaced apart from one another in the treatment direction A, which transport them one after the other through the washing device 1.

[0052] In the washing device 1, the solar modules are washed on both their front side, i.e. their glass side, and their back side, i.e. their film side.

[0053] Typically, each solar module stays in the washing device 1 shown for approximately 40 to 80 seconds, preferably 60 seconds.

[0054] In the illustrated embodiment, the washing device 1 comprises several roller-shaped high-pressure cleaning bars 17 with brushes and overlapping spray nozzles 18. In the illustrated embodiment, different brushes are used above and below the solar modules. The lower brushes, i.e., the brushes used for cleaning the back of the solar modules, are harder than the upper brushes, which are used for cleaning the glass surface of the solar modules.

[0055] The lower brushes are mounted so that they can be immersed in a frame 11 of the washing device 1.

[0056] The water used to wash the solar modules preferably passes through a reverse osmosis unit in a closed water circuit and is cleaned there.

[0057] In the embodiment shown, a driven roller conveyor 2 with a 90° rotation function for horizontally rotating the solar modules is arranged downstream of the washing device 1 in the treatment direction A. The solar modules continue to lie on the roller conveyor 2 with their front facing up. The roller conveyor 2 can also be omitted.

[0058] In treatment direction A, a drying device 3 then follows.

[0059] In the illustrated embodiment, the drying device 3 has fans 35 arranged above and below the solar modules immediately after the washing device 1. The fans 35 blow compressed air onto the solar modules to pre-dry them.

[0060] In this pre-dried state, the solar modules enter a paternoster of the drying device 3.

[0061] The drying device 3 is partially designed as a paternoster. This means that in the drying device 3, the washed solar modules are picked up in tiers of the paternoster and transported upwards and then downwards again without the solar modules having to be turned vertically.

[0062] In the illustrated embodiment, the levels of the paternoster are designed as frame-shaped solar module supports 31, each of which accommodates a solar module. In the paternoster, the solar modules rest on the solar module supports 31 with their front sides facing upwards.

[0063] The paternoster is located in a paternoster cabinet 32. At least one heating element 33 is located in or on the paternoster cabinet 32. In the illustrated embodiment, several heating elements 33 are arranged in the paternoster cabinet 32. The at least one heating element generates a temperature in the range of 55 to 60°C in the paternoster cabinet 32. This allows for the evaporation of any residual moisture remaining on the solar modules, particularly on the backs of the solar modules.

[0064] In the illustrated embodiment, a dehumidifier 36 is arranged in the paternoster cabinet 32. The dehumidifier 36 ensures that the moisture is removed from the moist, warm air within the paternoster cabinet.

[0065] A fan 34 for air circulation within the paternoster cabinet 32 ​​is also arranged on the paternoster cabinet 32. The fan 34 can be used to dehumidify the air within the paternoster cabinet 32.

[0066] In addition to its use as a drying device 3, the paternoster or a part thereof can be used as a coating treatment device, which is described in more detail below.

[0067] In other embodiments of the present invention (not shown), an infrared drying device can be provided downstream of the drying device 3 in the treatment direction A, in which the solar modules dried by the drying device 3 are subsequently dried or deep dried using pulsed infrared radiation. However, it has been shown that the solar modules are already so dry with the drying device 3 designed according to the invention alone that an infrared drying device may be dispensable.

[0068] In the embodiment shown, a driven roller conveyor 4 with a 90° rotation function is arranged downstream of the drying device 3. The roller conveyor 4 can also be omitted in other embodiments of the invention. A driven turning device 5 is arranged downstream of the roller conveyor 4, in which the solar modules are vertically rotated 180°. After this, the front side of the solar modules, i.e., the glass, is at the bottom.

[0069] In the embodiment shown, a driven roller conveyor 6 with flexible width adjustment and stops 61 for aligning the solar modules to a desired position is arranged following the turning device 5.

[0070] As schematically illustrated by the dashed lines, an infrared pretreatment device 7 can be provided adjacent to the roller conveyor 6 or between the turning device 5 and the roller conveyor 6. The infrared pretreatment device 7 can be used to heat the backs of the solar modules to a specific temperature prior to the subsequent backside coating. Here, the infrared pretreatment device 7 is preferably located above a conveyor on which the solar modules are transported.

[0071] In another embodiment, the infrared pretreatment device 7 can also be arranged between the drying device 3 and the turning device 5. In this case, it is preferably located below the conveyor device on which the solar modules are transported.

[0072] The solar modules then enter a solar module back coating device 8.

[0073] The solar module backside coating device 8 has a robot 9 on which an optical crack detection device 91, a crack filling and / or filling device 92 and a spraying device 93 are provided.

[0074] In the embodiment shown, the optical crack detection device 91 is a camera. If a crack in the backsheet of the respective solar module is detected by the optical crack detection device 91, the crack is filled using the crack filling and / or crack filling device 92. Once all cracks have been filled, the entire back of the solar module is sprayed with a plastic compound, preferably a polymer with an elastomer, using the spraying device 93.

[0075] If the plastic compound is viscous or pasty, a rolling device can be used instead of the spraying device 93 to apply the plastic compound to the back of the solar module.

[0076] The plastic compound can be a one-component or two-component plastic compound. The one-component plastic compound can contain a passive hardener that is only activated after coating and mixes with a first component of the one-component plastic compound. The hardener can be activated using infrared or UV radiation, for example.

[0077] If no crack is detected, the coating with the plastic compound is carried out immediately using the spraying device 93. In other embodiments of the invention, the crack detection device 91 and the crack filling and / or filling device 92 can also be omitted.

[0078] During crack filling and / or crack filling and spray coating of the respective solar module backside, the respective solar module rests on a lifting table 81 of the solar module backside coating device 8. A clamping device can be provided on the lifting table 81, with which mechanical tension can be automatically generated for the respective solar module to be coated.

[0079] An extraction air curtain 82 is formed on the side of the lifting table 81. The extraction air is generated by a low-pressure system 10.

[0080] In the illustrated embodiment, the solar module backside coating device 8 is followed by a driven roller conveyor 11 with a 90° lateral displacement. Here, no rotation or turning takes place; only a displacement of the solar modules takes place. The solar module backside remains at the top. This is followed by a roller conveyor 12 and another driven roller conveyor 13 with a 90° lateral displacement. In other embodiments of the present invention, the roller conveyors 11, 12, and 13 can also be omitted.

[0081] The next process module is a coating treatment device 14. As already indicated above, the coating treatment device 14 can be integrated into the paternoster of the drying device 3. However, it can also be designed as a separate device. The coating treatment device 14 is preferably designed as a paternoster, but this is not required.

[0082] In the coating treatment facility 14, the coated solar modules are exposed to infrared radiation. The infrared radiation may be pulsed, but does not have to be. In other embodiments of the present invention, other radiation and / or heat may also be used to treat the coated solar modules.

[0083] In the coating treatment device 14, a temperature gradient in a range of 35 degrees to 45 degrees, preferably 40 degrees, results from its inlet to its outlet.

[0084] In the coating treatment device 14, the coating material that has been applied to the respective solar module backside is dried and polymerized.

[0085] The coating treatment facility 14 is followed by a roller conveyor 15 for the removal of the completely refurbished solar modules.

[0086] A turning facility can be connected to runway 15.

[0087] The refurbished solar modules are then subjected to a visual inspection and a performance test, such as a flash test.

Claims

Patent claims Device (100) for renovating the backs of solar modules, which device has, in a treatment direction (A), a washing device (1), a drying device (3), a solar module back-side coating device (8), and a coating treatment device (14), characterized in that the drying device (3) is at least partially designed as a paternoster. Device according to claim 1, characterized in that the washing device (1) has washing elements and washing nozzles arranged above and below a solar module guide track. Device according to claim 1 or 2, characterized in that the washing device (1) has a closed water circuit. Device according to one of the preceding claims, characterized in that the paternoster has frame-shaped solar module supports (31).Device according to one of the preceding claims, characterized in that the paternoster is arranged in a paternoster cabinet (32) in and / or on which at least one heating element (33) is arranged. Device according to claim 5, characterized in that at least one dehumidifier is arranged in the paternoster cabinet (32). Device according to one of the preceding claims, characterized in that a solar module turning device (5) is arranged in the treatment direction (A) between the drying device (3) and the solar module backside coating device (8). Device according to claim 7, characterized in that an infrared pretreatment device (7) is arranged between the solar module turning device (5) and the solar module backside coating device (8). Device according to one of the preceding claims, characterized in that the solar module back-coating device (8) has an optical crack detection device (91), a crack filling and / or crack filling device (92), and a spraying or rolling device (93). Device according to one of the preceding claims, characterized in that an extraction air curtain (82) is formed laterally of the solar module back-coating device (8). Device according to one of the preceding claims, characterized in that the coating treatment device (14) is designed as a paternoster. Device according to one of the preceding claims, characterized in that the drying device (3) has a vacuum chamber (71) and / or a vacuum chamber (72) is arranged downstream of the coating treatment device (14) in the treatment direction (A).Device according to one of the preceding claims, characterized in that a solar module front-side nanocoating device (73) is arranged downstream of the coating treatment device (14) in the treatment direction (A). A method for renovating the backs of solar modules, in which the solar modules are washed, dried after washing, coated on their backs in a coating process after drying, and the applied coating is dried and polymerized, characterized in that the drying of the washed solar modules is carried out at least partially in a paternoster in which the solar modules are moved up and down while lying down. The method according to claim 13, characterized in that the solar modules are washed on both sides simultaneously. Method according to one of claims 13 or 14, characterized in that water used in washing the solar modules is guided in a closed water circuit. Method according to one of claims 13 to 15, characterized in that the paternoster is located in a paternoster cabinet (32) which is heated. Method according to claim 16, characterized in that the paternoster cabinet is dehumidified. Method according to one of claims 13 to 17, characterized in that the solar modules transported in a horizontal position are turned over after drying and before coating, with their rear sides facing upwards after turning. Method according to one of claims 13 to 18, characterized in that at least the rear sides of the solar modules are heated and / or deep-dried by infrared radiation after turning and before coating.Method according to one of claims 13 to 19, characterized in that after drying and before coating the solar modules, their backs are examined for cracks using an optical crack detection device (91). Method according to one of claims 13 to 20, characterized in that cracks detected by the crack detection device (91) are filled using a crack filling and / or crack filling device (92). Method according to one of claims 13 to 21, characterized in that a spray or roller coating is carried out on the backs of the solar modules during the coating process, wherein air is extracted by means of an air extraction curtain (82) arranged laterally of a conveyor device (16) on which the solar modules lie during the spray or roller coating. Method according to one of claims 13 to 22, characterized in that the coated solar modules are moved up and down while lying in a paternoster during the drying and polymerization of the coating. Method according to one of claims 13 to 23, characterized in that the solar modules are dried and / or the coating is dried and / or polymerized in a vacuum. Method according to one of claims 13 to 24, characterized in that after the coating on the back of the solar module has been dried and polymerized, a nanocoating is applied to the front of the solar module. Method according to one of claims 13 to 25, characterized in that a coating material is used for the coating which is hydrophilic and absorbs water before drying and polymerization.

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