Damage repairing method for pultrusion plate of wind power blade

Abstract

The invention belongs to the technical field of wind power equipment, and discloses a wind power blade pultrusion plate damage repairing method which comprises the steps that the two axial ends of a pultrusion plate of a damaged part of a wind power blade are polished into preset slope chamfers, and a to-be-repaired area is formed; an interlayer flow guide object is laid in the to-be-repaired area; lapping a pultrusion plate repairing piece in the to-be-repaired area; the to-be-repaired area is pumped to be in a vacuum state, and a curing substance is poured into the to-be-repaired area for curing; and an uneven area formed after curing is polished to be smooth. According to the damage repairing method for the wind power blade pultrusion plate, the large defects on the wind power blade pultrusion plate can be repaired, the reliability of damage repairing of the wind power blade pultrusion plate is effectively improved, the structural performance of the blade is improved, and the potential safety hazard and the rejection rate of the blade are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of wind power equipment, and in particular relates to a method for repairing damage of a pultruded plate of a wind power blade. Background Art

[0002] Pultruded board is a composite material profile produced by impregnating continuous glass fiber or carbon fiber with resin under the traction of traction equipment and curing the resin by heating the molding mold. In the past, the main beam of wind turbine blades was mainly formed by vacuum infusion process using uniaxial fiber fabric. Compared with fiber fabric infusion laminates, pultruded board has a higher fiber volume content and good process consistency, and the material performance (including but not limited to strength and modulus) is more excellent and stable. At the same time, the blade main beam made of pultruded board is not prone to wrinkles and other undesirable defects. Therefore, the main beam and other parts of wind turbine blades are mainly made by prefabricated pultruded board molding.

[0003] However, during the production, transportation and lifting of the blades, the main beam area of ​​the pultruded board is at risk of being bumped or impacted. The pultruded beam will crack or be damaged after being bumped. There is currently no effective repair method. When small damage occurs (defect thickness ≤ 2mm), fiber fabrics of the same specification and model are usually used for vacuum infusion to repair the main beam; when the main beam of the pultruded board is severely damaged (defect thickness > 2mm), the blade will be scrapped because there is no corresponding repair method.

[0004] The problem with repairing damaged pultruded plates of wind turbine blades by fiber fabric infusion is that the number and thickness of the fabric layers used are much greater than the thickness of the plate itself. This increase in thickness will affect the airfoil of the blade and increase the difficulty of reshaping the blade when coating the surface later. The structural performance and stability of the repaired blade are not good. If the wind turbine blade is scrapped due to damage to a certain part of the pultruded plate, it will cause great economic losses. Summary of the invention

[0005] To solve the above problems, the present invention provides a method for repairing damage to a pultruded plate of a wind turbine blade, which can repair larger defects on the pultruded plate of a wind turbine blade, effectively improve the reliability of repairing damage to the pultruded plate of a wind turbine blade, improve the structural performance of the blade, and reduce the safety hazards and scrap rate of the blade.

[0006] A method for repairing damage of a wind turbine blade pultruded plate provided by the present invention comprises:

[0007] Grind the axial ends of the pultruded plate at the damaged part of the wind turbine blade into preset slope chamfers to form the area to be repaired;

[0008] Laying interlayer guides in the area to be repaired;

[0009] Overlapping the pultruded board repair piece in the area to be repaired;

[0010] The area to be repaired is evacuated to a vacuum state, and a curing material is poured into the area to be repaired for curing;

[0011] Sand any uneven areas that form after curing to make them smooth.

[0012] Preferably, in the above-mentioned wind turbine blade pultruded plate damage repair method, the slope of the preset slope chamfer is not greater than 1:75.

[0013] Preferably, in the above-mentioned wind turbine blade pultruded plate damage repair method, the slope of the preset slope chamfer is 1:75, 1:100, 1:125 or 1:150.

[0014] Preferably, in the above-mentioned wind turbine blade pultruded plate damage repair method, the interlayer guide is a biaxial glass fiber fabric or a plain glass fiber fabric.

[0015] Preferably, in the above-mentioned method for repairing damaged pultruded plates of wind turbine blades, the pultruded plate repair piece has the same shape and size as the area to be repaired.

[0016] Preferably, in the above-mentioned wind turbine blade pultruded plate damage repair method, before grinding the axial ends of the pultruded plate at the damaged part of the wind turbine blade into preset slope chamfers, it also includes:

[0017] The material at the damaged part of the wind turbine blade is removed by grinding.

[0018] Preferably, in the above-mentioned wind turbine blade pultruded plate damage repair method, after grinding the axial ends of the pultruded plate at the damaged part of the wind turbine blade into preset slope chamfers to form the area to be repaired, it also includes:

[0019] Clean the area to be repaired.

[0020] Preferably, in the above-mentioned method for repairing damaged pultruded plates of wind turbine blades, the material of the pultruded plate repair piece is the same as the material of the damaged portion of the wind turbine blade.

[0021] Preferably, in the above-mentioned wind turbine blade pultruded plate damage repair method, the pouring of curing material into the area to be repaired for curing comprises:

[0022] Infusing epoxy resin, epoxy vinyl resin or polyurethane resin into the area to be repaired;

[0023] The area to be repaired is heated to 45° C. to 55° C. and then kept warm for 2 to 4 hours;

[0024] Continue to raise the temperature of the area to be repaired to 70° C. to 90° C. and keep it warm for 3 to 5 hours;

[0025] Stop heating the area to be repaired and allow the area to cool down naturally.

[0026] Preferably, in the above-mentioned wind turbine blade pultruded plate damage repair method, after pouring the curing material into the area to be repaired for curing, the method further comprises:

[0027] Check whether there are any infusion defects in the repaired area after curing;

[0028] Detecting whether the glass transition temperature of the repaired area is not less than 75° C.;

[0029] When there is no perfusion defect in the repaired area and the glass transition temperature is not less than 75° C., the repair is judged to be qualified, otherwise it is unqualified.

[0030] From the above description, it can be known that the above-mentioned wind turbine blade pultruded plate damage repair method provided by the present invention includes grinding the axial ends of the pultruded plate at the damaged part of the wind turbine blade into preset slope chamfers to form an area to be repaired; laying interlayer guides in the area to be repaired; overlapping the pultruded plate repair part in the area to be repaired; evacuating the area to be repaired to a vacuum state, and pouring a solidifying material into the area to be repaired for solidification; and polishing the uneven area formed after solidification. This same pultruded plate material can be better matched with the pultruded plate at the damaged part, and the bonding strength after repair is higher. Therefore, this method can be used to repair larger defects on the pultruded plate of the wind turbine blade, effectively improve the reliability of wind turbine blade pultruded plate damage repair, improve the blade structural performance, and reduce the safety hazards and scrap rate of the blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0032] Figure 1 A schematic diagram of an embodiment of a method for repairing damage to a pultruded plate of a wind turbine blade provided by the present invention;

[0033] Figure 2 Schematic diagram of the repair of damaged pultruded plates of wind turbine blades. DETAILED DESCRIPTION

[0034] The core of the present invention is to provide a method for repairing damage to a pultruded plate of a wind turbine blade, which can repair larger defects on the pultruded plate of a wind turbine blade, effectively improve the reliability of repairing damage to the pultruded plate of a wind turbine blade, improve the structural performance of the blade, and reduce the safety hazards and scrap rate of the blade.

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The present invention provides a method for repairing a wind turbine blade pultruded plate damage. Figure 1 As shown, Figure 1 This is a schematic diagram of an embodiment of a method for repairing a damaged pultruded plate of a wind turbine blade provided by the present invention. The method may include the following steps:

[0037] S1: Grinding the axial ends of the pultruded plate at the damaged part of the wind turbine blade into preset slope chamfers to form an area to be repaired;

[0038] It should be noted that the reference Figure 2 , Figure 2 This is a schematic diagram of repairing damage to a pultruded plate of a wind turbine blade, which shows a damaged portion 1 of the wind turbine blade and a preset slope chamfer 2 formed after grinding. The damaged portion 1 of the wind turbine blade can be located at the main beam or the trailing edge, both of which can be made of pultruded plates. Of course, other portions made of pultruded plates can also be repaired using this method, and chamfering the axial ends of the pultruded plates at the damaged portion is to form a buffer, so that the pultruded plate repair piece has a larger contact area with the damaged portion, and the connection between the two is more secure and less likely to fall off. Specific grinding steps may include: placing the pultruded plate on the workbench of the grinding equipment, fixing the plate with a pressing plate mechanism or other fixing device to prevent movement during the grinding process, using acetone or other suitable solvents to clean the damaged area, remove dust, oil and other impurities, check the damage range, determine the area that needs to be polished, and then start the grinding equipment. The axial ends of the pultruded plate at the damaged part are ground into slope chamfers according to the preset ratio. If the local area is too narrow, the ratio can be adjusted appropriately, but the transition should be smooth. During the grinding process, the height and position of the grinding equipment are adjusted as needed to ensure the uniformity and accuracy of the chamfer. After the grinding is completed, check whether the size and angle of the chamfer meet the preset requirements. If necessary, further adjustments and grinding can be performed. After the grinding is completed, the grinding area needs to be cleaned to remove dust and impurities for subsequent repair operations.

[0039] S2: Laying interlayer guides in the area to be repaired;

[0040] It should be noted that, continue to refer to Figure 2 , wherein the interlayer guide 3 is shown. The purpose of this step is to guide the resin to evenly penetrate into the various layers of the area to be repaired, avoid repair defects caused by uneven distribution of resin, and improve the repair quality. Through the effect of the guide, the generation of bubbles and gaps can also be reduced, and the structural strength after repair can be enhanced. The guides that can be used include guide nets, guide felts, etc. This interlayer guide can preferably have a surface density of 200g / m 2 The fiberglass fabric, specifically biaxial fiberglass fabric or plain fiberglass fabric, should be used. Its material and performance should match the material of the area to be repaired. Lay the deflector between the layers of the area to be repaired, ensure that the deflector is flat and wrinkle-free, and then use an appropriate fixing method (such as tape or clamps) to fix the deflector to the area to be repaired to prevent it from shifting in subsequent operations. The size and shape of this deflector should match the area to be repaired to ensure that it can completely cover the repair area. After laying, carefully check whether there are bubbles or gaps between the deflector and the area to be repaired, and adjust it if necessary.

[0041] S3: Overlap the pultruded board repair piece in the area to be repaired;

[0042] For details, please refer to Figure 2 , Figure 2 The pultruded plate repair piece 4 overlapped in the area is shown, and it can be seen that its lower part matches the shape and size of the area to be repaired, while the upper surface is a plane, so that it can ensure consistency with the surface of other parts. This step can specifically include the following sub-steps: according to the size and shape of the area to be repaired, a pultruded plate repair piece that matches it is made to ensure that the material of the repair piece is consistent with the original blade material, and materials with the same physical performance parameters as the original blade are preferentially selected. The pultruded plate repair piece is then placed in the area to be repaired to ensure that the repair piece fits tightly against the surface of the area to be repaired. The overlap length of the repair piece should comply with relevant specifications. For example, when the repair damage is less than 20 cm, the minimum axial overlap length of each layer is 5 cm. The repair piece is then fixed in the area to be repaired using a clamp or tape to prevent displacement in subsequent operations.

[0043] S4: evacuating the area to be repaired to a vacuum state, and pouring a curing material into the area to be repaired for curing;

[0044] It should be noted that the following sub-steps may be specifically included: laying a demoulding cloth in the area to be repaired to cover the entire repair area, laying a guide net or guide felt on the demoulding cloth to ensure that it is flat and wrinkle-free, laying a vacuum bag film on the guide net, and ensuring that the vacuum bag film is well sealed with the edge of the area to be repaired, arranging a vacuum exhaust system, and the exhaust ports need to be evenly arranged, with a number of not less than 2, and the spacing may preferably be 1.5 meters to 3 meters, starting the vacuum pump, pumping the vacuum degree to below 40mbar (about -0.092MPa), and maintaining the pressure for 15 minutes to ensure that the vacuum value is 0.005MPa to 0.007MPa to verify the sealing of the vacuum system, and then using a glue injection machine with a catheter to inject the resin into the area to be repaired through the glue inlet pipe. During the injection process, keep the vacuum pump in the exhaust state to ensure that the resin can be evenly distributed and completely infiltrate the reinforcing material. After the injection is completed, close the glue injection pipe, continue to vacuum to remove bubbles and make the accumulation dense, and heat and cure the repair area according to the curing requirements of the resin. For example, heat the repair area to 40℃ for insulation, then start the heating device to raise the resin temperature to 70℃, and the curing time is 5 hours. The vacuum degree should be adjusted according to the local atmospheric pressure. Too high may make it impossible to achieve vacuum, and too low will lead to too high resin content, affecting the structural strength. Select a resin system that matches the original blade material to ensure that its performance meets the repair requirements. During the infusion process, maintain a vacuum state to exclude bubbles and avoid repair defects caused by bubbles. Strictly follow the curing requirements of the resin to ensure that the repair area has sufficient strength after curing.

[0045] S5: Grind the uneven areas formed after curing to make them smooth.

[0046] After curing, remove auxiliary materials such as vacuum bag film and guide net, and polish any uneven areas such as steps that may appear. The specific steps may include the following sub-steps: Before polishing, carefully check the cured repair area to confirm whether it is completely cured and whether there are obvious defects or uneven areas. If incomplete curing or other problems are found, they need to be processed first to ensure that the repair area meets the polishing conditions. According to the size and unevenness of the repair area, choose the appropriate polishing tool. Common polishing tools include: (1) Angle grinder: suitable for larger or thicker repair areas, which can quickly remove excess material; (2) Handheld sander: suitable for medium-sized repair areas, with a more uniform polishing effect; (3) Hand-held sandpaper: suitable for small areas or fine polishing, which can control the polishing accuracy; (4) Polishing machine: used for the final polishing to make the surface smooth. First use coarser sandpaper (such as 80 or 120 mesh) for preliminary grinding to remove obvious uneven areas. Then maintain uniform force during grinding to avoid local over-grinding, which will cause new unevenness. After preliminary grinding, use a ruler or level to check the flatness of the repaired area and find out the areas that still need to be polished. For larger uneven areas, you can use a marking pen to mark them for subsequent focus grinding. Then use finer sandpaper (such as 240 or 320 mesh) for fine grinding to gradually improve the flatness of the repaired area. During the grinding process, you can check the flatness multiple times to ensure that the repaired area gradually becomes flat. When the repaired area reaches the basic level, After leveling, use a polishing machine with polishing paste to polish the surface to make it smooth. Maintain a uniform speed and force during polishing to avoid local overheating or damage to the surface. After grinding and polishing, use a clean cloth or compressed air to clean the repair area to remove dust and debris generated by grinding. During the grinding process, pay attention to protecting the blade surface around the repair area to avoid unnecessary damage. You can use a protective film or tape to cover the surrounding area. Grinding should be done along the fiber direction of the blade to avoid damaging the structural fibers of the blade. After grinding, the repair area should be quality inspected to ensure that its flatness, smoothness and structural integrity meet the requirements.

[0047] From the above description, it can be known that in the embodiment of the above-mentioned wind turbine blade pultruded plate damage repair method provided by the present invention, since it includes grinding the axial ends of the pultruded plate at the damaged part of the wind turbine blade into preset slope chamfers to form an area to be repaired; laying interlayer guides in the area to be repaired; overlapping the pultruded plate repair part in the area to be repaired; evacuating the area to be repaired to a vacuum state, and pouring a solidifying material into the area to be repaired for solidification; and polishing the uneven area formed after solidification. This same pultruded plate material can be better matched with the pultruded plate at the damaged part, and the bonding strength after repair is higher. Therefore, this method can be used to repair larger defects on the pultruded plate of the wind turbine blade, effectively improve the reliability of wind turbine blade pultruded plate damage repair, improve the blade structural performance, and reduce the safety hazards and scrap rate of the blade.

[0048] In a specific embodiment of the above-mentioned wind turbine blade pultruded plate damage repair method, the slope of the above-mentioned preset slope chamfer is not greater than 1:75. Specifically, the slope of the preset slope chamfer may preferably be 1:75, 1:100, 1:125 or 1:150. This slope will affect the fluidity of the resin and the fit of the repaired part, and thus directly affect the quality of the repair and the structural strength. Too large or too small a chamfer angle may affect the structural strength after the repair. It should be noted that this slope is expressed in the form of "1:X", where "1" represents a unit length in the vertical direction, and "X" represents a unit length in the horizontal direction. For example, 1:100 means that for every 1 unit length moved in the vertical direction, 100 unit lengths are moved in the horizontal direction. Specifically, the advantage of a slope of 1:75 is that the chamfer is steeper, which is suitable for smaller repair areas and can quickly form a transition. The advantage of a slope of 1:100 is that it is suitable for most repair scenarios and can better balance resin fluidity and structural strength. The advantage of a slope of 1:125 is that this gentle chamfer is suitable for larger repair areas and the resin flows more smoothly. The advantage of a slope of 1:150 is that it is suitable for large-area repairs and has the best resin flow. Regardless of the chamfer angle you choose, you need to ensure processing accuracy to avoid repair defects caused by uneven chamfers. When pouring resin, make sure that the resin can fully penetrate the chamfer area to avoid poor resin flow caused by too large or too small a chamfer angle. After the chamfering process is completed, the repair area needs to be cleaned to remove dust and impurities, and check whether the flatness and angle of the chamfer meet the requirements.

[0049] In another specific embodiment of the above-mentioned wind turbine blade pultruded plate damage repair method, the pultruded plate repair piece and the area to be repaired have the same shape and size, and the edge of the pultruded plate repair piece should fit closely with the edge of the area to be repaired to avoid gaps or overlaps, so as to ensure the structural integrity and mechanical properties after the repair. Specifically, when making the pultruded plate repair piece, it is necessary to use high-precision cutting tools and equipment to ensure the dimensional accuracy of the repair piece. For complex repair areas, CNC cutting equipment can be used for processing to improve accuracy. During the repair process, the pultruded plate repair piece should fit closely with the surface of the area to be repaired to ensure that the resin can penetrate evenly. After the repair is completed, the repair area needs to be ground and polished to ensure a smooth and flat surface. After the repair is completed, the repair area should be quality inspected to ensure that its flatness, smoothness and structural integrity meet the requirements.

[0050] In another specific embodiment of the above-mentioned wind turbine blade pultruded plate damage repair method, before grinding the axial ends of the pultruded plate at the damaged part of the wind turbine blade into a preset slope chamfer, the following step may also be included: grinding to remove the material at the damaged part of the wind turbine blade. Specifically, a suitable grinding tool may be selected according to the size and shape of the damaged part. Common grinding tools include: (1) Angle grinder: suitable for larger or thicker damaged areas, which can quickly remove materials; (2) Hand-held sander: suitable for medium-sized damaged areas, with a more uniform grinding effect; (3) Hand-made sandpaper: suitable for small areas or fine grinding, which can control the grinding accuracy. First use coarser sandpaper (such as 80 mesh or 120 mesh) for preliminary grinding to remove the material of the damaged area. Maintain uniform force during grinding to avoid local over-grinding and cause new damage. After preliminary grinding, check whether the material of the damaged area has been completely removed to ensure that the surface of the damaged area is flat. If it is found that there is still damaged material remaining, it is necessary to continue grinding until the material of the damaged area is completely removed, and then use finer sandpaper (such as 240 mesh or 320 mesh) for fine grinding to further flatten the surface of the damaged area. During the grinding process, you can check the flatness several times to ensure that the surface of the damaged area gradually becomes flat. After grinding, use a clean cloth or compressed air to clean the damaged area to remove dust and debris generated by grinding, ensure that the surface of the damaged area is clean, free of oil and impurities, and prepare for subsequent slope chamfer grinding and repair operations. Grinding should be done along the fiber direction of the blade to avoid damaging the structural fibers of the blade. The force and time should be controlled during the grinding process to avoid excessive grinding that may cause thinning of the damaged area or the appearance of new defects. During the grinding process, the depth of the damage should be checked regularly to ensure that excessive material is not removed, which will affect the structural strength of the blade. In this way, the material of the damaged part of the wind turbine blade can be effectively polished away, providing a good foundation for subsequent slope chamfer grinding and other repair operations.

[0051] In a preferred embodiment of the above-mentioned wind turbine blade pultruded plate damage repair method, after grinding the axial ends of the pultruded plate at the damaged part of the wind turbine blade into preset slope chamfers to form the area to be repaired, the following steps may also be included: cleaning the area to be repaired. It should be noted that this cleaning work can ensure that the surface of the repair area is clean and free of impurities, thereby improving the quality of repair. Specifically, a clean brush or compressed air can be used to clean the dust and debris generated during the grinding process. If a brush is used, soft bristles should be selected to avoid scratching the surface of the repair area. If compressed air is used, the airflow direction should be ensured to be away from the repair area to avoid blowing dust to other parts. Then use a clean cloth or dust-free paper, dip in an appropriate amount of detergent (such as alcohol or acetone), and gently wipe the surface of the area to be repaired. The detergent should be a solvent that is non-corrosive to the repair material and the blade material. When wiping, it should be done in the same direction to avoid rubbing back and forth to avoid damaging the surface. After cleaning, carefully check the surface of the area to be repaired to ensure that there is no residual dust, debris, oil or other impurities. If impurities are still found, the cleaning steps should be repeated until the surface is completely clean. The area to be repaired should be dried naturally or gently wiped dry with a clean cloth to ensure that the surface of the repair area is completely dry and no moisture remains to avoid affecting subsequent repair operations.

[0052] In another preferred embodiment of the above-mentioned wind turbine blade pultruded plate damage repair method, the material of the pultruded plate repair piece is the same as the material of the damaged part of the wind turbine blade. Specifically, the repair piece made of pultruded plate is more suitable for repairing the damaged part of the pultruded plate of the wind turbine blade. The fiber type, resin system, fiber content, etc. of the repair piece should be consistent with the original blade material. For example, if the original blade uses a large-tow carbon fiber pultruded plate, the repair piece should also use a carbon fiber pultruded plate of the same specification. Regarding the material, if the original blade uses a glass fiber pultruded plate, the repair piece should use a glass fiber pultruded plate of the same specification. , glass fiber pultruded board has good impact resistance and cost-effectiveness, and is suitable for repairs with medium strength requirements. This ensures that the repaired blades are consistent with the original blades in terms of mechanical properties (such as strength, modulus, toughness, etc.) and durability (such as fatigue resistance, anti-aging, etc.). In addition, the use of the same material can avoid interface problems caused by material differences, such as mismatched thermal expansion coefficients, poor chemical compatibility, etc., thereby improving the structural integrity of the repair area. The same material is also easier to achieve good bonding and fusion, reducing stress concentration after repair, improving the repair effect, and enhancing the operational reliability of the blade.

[0053] In another preferred embodiment of the above-mentioned wind turbine blade pultruded plate damage repair method, pouring a solidifying material into the area to be repaired for solidification may specifically include the following steps:

[0054] Infuse epoxy resin, epoxy vinyl resin or polyurethane resin into the area to be repaired. Specifically, the appropriate type of resin can be selected according to the material characteristics and usage requirements of the repair area. Among them, epoxy resin has good bonding properties and high strength, and is suitable for most repair scenarios. Epoxy vinyl resin has excellent corrosion resistance and good mechanical properties. Polyurethane resin has good flexibility and impact resistance, and is suitable for repair areas that require high toughness. Lay diversion materials (such as diversion nets or diversion felts) in the area to be repaired to ensure that the resin can be evenly distributed. Use a vacuum infusion system to evenly infuse the selected resin into the repair area through the diversion materials. Maintain a vacuum state during the infusion process to remove bubbles and ensure that the resin fully infiltrates the repair part and the area to be repaired.

[0055] Heat the area to be repaired. When the temperature of the area to be repaired is raised to 45°C to 55°C, keep it warm for 2 to 4 hours. Specifically, heating equipment (such as a hot air gun, heating blanket, etc.) can be used to slowly heat the area to 45°C to 55°C. The heating rate can be controlled at 5°C to 10°C per hour to avoid thermal stress caused by excessive temperature difference. After reaching the target temperature, maintain the temperature for 2 to 4 hours to ensure the initial curing of the resin.

[0056] Continue to raise the temperature of the area to be repaired to 70°C to 90°C and keep it warm for 3 to 5 hours. Specifically, the heating rate should also be controlled at 5 to 10°C per hour to ensure a smooth temperature change. After reaching the target temperature, maintain the temperature for 3 to 5 hours to ensure that the resin is completely cured.

[0057] Stop heating the area to be repaired and allow it to cool down naturally. Specifically, after the resin is cured, stop the heating equipment and allow the area to cool down naturally. During the natural cooling process, rapid cooling should be avoided to prevent thermal stress caused by excessive temperature difference.

[0058] In a specific example, the above perfusion process is first preheated at 30°C, and after the perfusion is completed, the temperature is raised to 50°C and maintained for 4 hours, and then the temperature is raised to 80°C and maintained for 3.5 hours, and the heating is turned off and the temperature is naturally cooled.

[0059] The above steps ensure that the resin in the repair area is fully cured, thereby restoring the structural strength and performance of the blade.

[0060] Furthermore, after the curing material is poured into the area to be repaired and cured, the following steps may be included:

[0061] Detect whether there are any infusion defects in the repaired area formed after curing. Specifically, non-destructive testing techniques (such as ultrasonic testing, X-ray testing, etc.) can be used to check whether there are any infusion defects in the repaired area after curing, such as bubbles, pores, inclusions, cracks, etc. Ultrasonic testing technology can detect defects such as pores, bubbles, cracks, etc. in composite materials, and can further determine the density, fiber buckling, elastic modulus and other characteristics of the material. X-ray testing is suitable for detecting volume defects, such as pores and inclusions in the resin, and can also detect cracks perpendicular to the blade surface;

[0062] Check whether the glass transition temperature of the repaired area is not less than 75°C. Differential scanning calorimetry (DSC), thermomechanical analysis (TMA) or dynamic mechanical analysis (DMA) can be used to detect the glass transition temperature of the repaired area. The glass transition temperature is an important indicator to measure the degree of resin curing.

[0063] When there are no injection defects in the repaired area and the glass transition temperature is not less than 75°C, the repair is considered qualified. Otherwise, it is unqualified and needs to be reworked or further processed. In addition, the repaired surface should be flat, without defects such as coating peeling and cracks, so as to ensure the performance and quality of the wind turbine blade after repair and ensure the safe operation of the blade.

[0064] In summary, the above-mentioned wind turbine blade pultruded plate damage repair method can be used to repair damage defects in the pultruded plate main beam and other parts based on the chamfered overlap method of the pultruded plate, with little impact on the original structure of the pultruded plate main beam, and the original mechanical properties of the pultruded plate main beam can be restored. The damage defects of single-layer and multi-layer pultruded plates in the pultruded plate main beam and other parts can be repaired. It has a wider range of applications, more stable material properties, and higher repair reliability, and can effectively reduce the safety hazards and blade scrap rate caused by damage to the pultruded plate main beam and other parts.

[0065] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for repairing damaged pultruded plates of wind turbine blades, characterized in that: include: Grind the axial ends of the pultruded plate at the damaged part of the wind turbine blade into preset slope chamfers to form the area to be repaired; Laying interlayer guides in the area to be repaired; Overlapping the pultruded board repair piece in the area to be repaired; The area to be repaired is evacuated to a vacuum state, and a curing material is poured into the area to be repaired for curing; Sand any uneven areas that form after curing to make them smooth.

2. The wind turbine blade pultruded plate damage repair method according to claim 1, characterized in that: The slope of the preset slope chamfer is not greater than 1:

75.

3. The wind turbine blade pultruded plate damage repair method according to claim 2, characterized in that: The slope of the preset slope chamfer is 1:75, 1:100, 1:125 or 1:

150.

4. The wind turbine blade pultruded plate damage repair method according to claim 3 is characterized in that: The interlayer flow guide is a biaxial glass fiber fabric or a plain glass fiber fabric.

5. The wind turbine blade pultruded plate damage repair method according to claim 1, characterized in that: The pultruded board repair piece has the same shape and size as the area to be repaired.

6. The wind turbine blade pultruded plate damage repair method according to claim 1, characterized in that: Before grinding the axial ends of the pultruded plate at the damaged part of the wind turbine blade into preset slope chamfers, the method also includes: The material at the damaged part of the wind turbine blade is removed by grinding.

7. The wind turbine blade pultruded plate damage repair method according to claim 6, characterized in that: After grinding the axial ends of the pultruded plate at the damaged part of the wind turbine blade into preset slope chamfers to form the area to be repaired, the method also includes: Clean the area to be repaired.

8. The wind turbine blade pultruded plate damage repair method according to claim 1, characterized in that: The material of the pultruded plate repair piece is the same as the material of the damaged part of the wind turbine blade.

9. The wind turbine blade pultruded plate damage repair method according to claim 1, characterized in that: The pouring of curing material into the area to be repaired for curing comprises: Infusing epoxy resin, epoxy vinyl resin or polyurethane resin into the area to be repaired; The area to be repaired is heated to 45° C. to 55° C. and then kept warm for 2 to 4 hours; Continue to raise the temperature of the area to be repaired to 70° C. to 90° C. and keep it warm for 3 to 5 hours; Stop heating the area to be repaired and allow the area to cool down naturally.

10. The method for repairing wind turbine blade pultruded plate damage according to any one of claims 1 to 9, characterized in that: After the curing material is poured into the area to be repaired and cured, the method further comprises: Check whether there are any infusion defects in the repaired area after curing; Detecting whether the glass transition temperature of the repaired area is not less than 75° C.; When there is no perfusion defect in the repaired area and the glass transition temperature is not less than 75° C., the repair is judged to be qualified, otherwise it is unqualified.

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