Wind power blade core material, wind power blade, wind power generation device, and method for detecting defects of wind power blade

Abstract

The application relates to the field of wind power generation, and provides a wind power blade core material, a wind power blade, a wind power generation device and a wind power blade defect detection method.The wind power blade core material comprises a polymer matrix and a colorant, the colorant is uniformly dispersed in the polymer matrix, the brightness parameter of the colorant is 5-30, and the mass of the colorant accounts for 0.1%-5% of the mass of the polymer matrix.At least, the missing detection rate and the detection time can be reduced, the overall quality of the wind power blade can be improved, and the production efficiency can be improved.

Description

Technical Field

[0001] This application relates to the field of wind power generation, and in particular to a method for detecting defects in wind turbine blade core material, wind turbine blades, wind power generation devices, and wind turbine blades. Background Technology

[0002] As a core component of wind power generation devices, the quality of wind turbine blades often determines the overall quality of the entire device. During blade production, a process typically involves first laying up core materials and fiberglass in a mold, followed by injection molding, and then closing the mold to produce the blade. Before and after injection molding, the core material and blade undergo defect inspection to identify cracks, voids, or impurities, ensuring the blade's structural safety meets standards. Accurately identifying the depth and extent of structural damage is crucial for ensuring blade safety and extending its lifespan during the manufacturing, service, and maintenance of wind turbine blades.

[0003] However, it is currently difficult to fully detect defects in wind turbine blades, resulting in a high rate of missed detections (usually above 15%). Moreover, the detection process is time-consuming, affecting production efficiency. Summary of the Invention

[0004] This application provides a method for detecting defects in wind turbine blade core material, wind turbine blades, wind power generation devices, and wind turbine blades. This method is beneficial in reducing the missed detection rate and detection time, thereby improving the overall batch quality of wind turbine blades and increasing production efficiency.

[0005] According to some embodiments of this application, one embodiment of this application provides a wind turbine blade core material, including a polymer matrix and a colorant, wherein the colorant is uniformly dispersed in the polymer matrix, the brightness parameter of the colorant is 5~30, and the mass of the colorant accounts for 0.1%~5% of the mass of the polymer matrix.

[0006] According to some embodiments of this application, a second aspect of this application also provides a wind turbine blade, including a shell, a cavity provided in the shell, a main beam and a web plate provided in the cavity, the main beam being located on the surface of the shell, the web plate being vertically arranged, and the sidewall of the web plate being connected to the surface of the shell; the shell includes the aforementioned wind turbine blade core material.

[0007] According to some embodiments of this application, a third aspect of this application also provides a wind power generation device, including a tower body and the aforementioned wind turbine blades, with the wind turbine blades located at the top of the tower body.

[0008] According to some embodiments of this application, a fourth aspect of this application also provides a method for detecting defects in wind turbine blades, comprising the following steps: illuminating the wind turbine blade with a light source to obtain a second imaging result, and determining the defect area in the wind turbine blade based on the second imaging result; the light intensity of the light source is not less than 1000 Lux; and the grayscale contrast between the normal area and the defect area is not less than 100:1.

[0009] The technical solution provided in this application has at least the following advantages: The wind turbine blade core material provided in this application embodiment contains 0.1% to 5% colorant by weight of the polymer matrix, and the brightness parameter of the colorant is 5 to 30. This ensures that even after the wind turbine blade core material is manufactured into a wind turbine blade, its color contrast is sufficiently clear. When using light to irradiate the wind turbine blade for defect detection, the defect area can be determined based on the difference in color contrast. Furthermore, in this application embodiment, since the colorant accounts for 0.1% to 5% of the polymer matrix mass, the colorant can be uniformly distributed in the polymer matrix to facilitate the differentiation of defect areas, and it has virtually no negative impact on the strength of the wind turbine blade core material or the strength of the manufactured wind turbine blade. Attached Figure Description

[0010] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the structure of the wind turbine blade core material in the embodiments of this application; Figure 2 The images shown are actual pictures of the wind turbine blade core material in the embodiments and Comparative Example 1 of this application.

[0012] Reference numerals: 001 - Wind turbine blade core material; 100 - Polymer matrix; 200 - Colorant. Detailed Implementation

[0013] As the background technology indicates, current technology for detecting defects in wind turbine blades suffers from a high rate of missed detections and is time-consuming. This not only affects the overall batch quality of wind turbine blades but also reduces production efficiency. The time-consuming process and high missed detection rate are due to the characteristics of wind turbine blades. The interlayer of wind turbine blades typically employs a sandwich structure, with core materials such as foam or balsa wood having a color close to that of the laminate after injection. This presents multiple challenges for defect identification. Wind turbine blades usually undergo close-range quality inspection at the manufacturing and repair sites: quality inspectors need to determine whether damage has penetrated the interlayer core material before the blade leaves the factory or during repair to develop the appropriate repair plan. For example, during blade manufacturing, mold sticking damage may occur: the panel is torn during demolding, leaving obvious tears on the surface, but it's impossible to directly determine whether the internal core material is delaminated or damaged. To confirm the situation, it is often necessary to cut or grind the panel for inspection, which not only increases the workload of repairs but also reduces production efficiency. Furthermore, under long-term service or impact and fatigue loads, delamination may occur between the panel and the core material within the sandwich structure. This damage does not present obvious cracks or color differences on the surface, making it almost impossible to detect with the naked eye or ordinary imaging using traditional core materials. Moreover, due to the difficulty in identifying delamination in sandwich structures, the extent of delamination often relies on specialized testing instruments such as ultrasonic and thermal imaging. This testing process is time-consuming and inefficient, increasing maintenance costs. For example, during transportation, localized delamination may occur inside the blade due to vibration or impact, while the exterior remains almost intact. Only after a period of operation does bulging appear in the damaged area, by which time the delamination has expanded, leading to increased repair costs and downtime losses.

[0014] Based on this, this application provides a method for detecting defects in wind turbine blade core material, wind turbine blade, wind power generation device, and wind turbine blade. In this application, by modifying the wind turbine blade core material, the accuracy of wind turbine blade defect detection can be improved, and the detection time can be reduced, thereby improving the overall batch quality of wind turbine blades and increasing the production efficiency of wind turbine blades.

[0015] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0016] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0017] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0018] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. For example, if the device or element in the illustration is inverted, then the element described as "below," "under," "below," or "bottom" of other elements or features will be oriented "above" or "top" of other elements or features. Therefore, the term "below" may cover both above and below orientation depending on the context in which the term is used, which will be obvious to those skilled in the art. Materials may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatial relative descriptive terms used herein may be interpreted accordingly.

[0019] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0020] In the description of embodiments of this application, the terms "about," "approximately," "roughly," or "about" for referring to a specific parameter include numerical values, and those skilled in the art will understand that the deviation from the numerical value is within the acceptable tolerance of the specific parameter. For example, "about" or "about" for a numerical value may include additional numerical values ​​that are in the range of 90.0% to 110.0% of the numerical value, such as in the range of 95.0% to 105.0%, 97.5% to 102.5%, 99.0% to 101.0%, 99.5% to 100.5%, or 99.9% to 100.1%.

[0021] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. Furthermore, when describing a component as "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0022] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. The formation or provision of a second component above or on a first component, or on the surface of a first component, or on one side of a first component, may include embodiments where the first and second components are in direct contact, and may also include embodiments where an additional component may be present between the first and second components, thereby preventing direct contact between the first and second components. For simplicity and clarity, various components may be drawn at different scales. In the drawings, some layers / components may be omitted for simplicity. Unless otherwise specified, the formation or provision of a second component on the surface of a first component refers to direct contact between the first and second components. The term "component" may refer to a layer, film, region, portion, structure, etc.

[0023] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0024] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0025] This application provides a wind turbine blade core material, comprising a polymer matrix and a colorant. The colorant is uniformly dispersed in the polymer matrix, and the brightness parameter of the colorant is 5-30. The mass of the colorant accounts for 0.1%-5% of the mass of the polymer matrix. A schematic diagram of the wind turbine blade core material is shown below. Figure 1 As shown, the colorant is uniformly distributed in the polymer matrix.

[0026] The inventors discovered that the reason why defects such as microcracks, pores, impurities, and delamination whitening on the surface of wind turbine blade core materials cannot be identified after they are cast into wind turbine blades is because the core material is light in color and has low color contrast. Therefore, the wind turbine blade core material provided in this application contains 0.1% to 5% of a colorant by weight of the polymer matrix, and the brightness parameter of the colorant is 5 to 30. This ensures that even after the wind turbine blade core material is manufactured into a wind turbine blade, its color contrast is sufficiently obvious. When using light to irradiate the wind turbine blade for defect detection, the defect area can be determined based on the difference in color contrast. If the brightness parameter of the colorant is too low, the defect area will not be obvious, making it difficult to determine the defect area. If the brightness parameter of the colorant is too high, non-defect areas may be easily identified as defect areas. Furthermore, in this application embodiment, since the colorant accounts for 0.1% to 5% of the polymer matrix by weight, the colorant can be evenly distributed in the polymer matrix to facilitate the differentiation of defect areas, and it has virtually no negative impact on the strength of the wind turbine blade core material or the strength of the manufactured wind turbine blade. For example, the mass of the colorant can be 0.1%, 0.8%, 1.2%, 2.4%, 3.6%, 4.5%, 5% of the polymer matrix mass, or within a range of any two of the above values.

[0027] This application does not impose any particular restrictions on the type or color of the colorant, as long as the brightness parameter is within the range of 5 to 30, which is measured according to ISO 11664-4 standard. For example, the colorant may include, but is not limited to, at least one of carbon black, iron oxide, or masterbatch. "Masterbatch" is a polymeric material colorant specifically used for coloring plastic products; it can also be called pigment concentrate or color masterbatch. It is made by uniformly dispersing high-concentration pigments or dyes in a resin carrier, and features high coloring efficiency, good dispersibility, and ease of use. Masterbatch mainly consists of three basic elements: pigments or dyes, carriers, and additives. It is an aggregate obtained by uniformly loading an excessive amount of pigment into a resin, therefore its coloring power is higher than that of the pigment itself. This application does not impose any particular requirements on the molding process or carrier values ​​of the masterbatch, as long as they meet the purpose of this application.

[0028] In some embodiments of this application, the average particle size of the colorant is generally in the range of 0.5μm to 5μm. This is beneficial for the colorant to be evenly distributed in the core material of the wind turbine blade, and it is also less likely to reduce the strength of the core material of the wind turbine blade.

[0029] To ensure good mechanical strength of the wind turbine blade core material and to facilitate better color development of the colorant, in some embodiments of this application, the polymer matrix typically includes polyethylene terephthalate (PET). Additionally, in some embodiments of this application, the density of the polymer matrix is ​​generally around 50 kg / m³. 3 ~300kg / m 3 Within this range, it is beneficial for wind turbine blade core materials and wind turbine blades to have good mechanical strength while reducing their weight.

[0030] In addition, since wind turbine blade core materials are usually foamed, foaming agents are also added to the wind turbine blade core materials in some embodiments of this application.

[0031] This application does not impose any particular limitation on the preparation method of wind turbine blade core material, as long as it meets the purpose of this application. As an example, in some embodiments of this application, the preparation process of the wind turbine blade core material is as follows: First, the colorant is mixed with polymer particles to form a premix; then the premix is ​​melt-blended to form a masterbatch; finally, a foaming agent is added to the masterbatch for foaming and molding.

[0032] As described above in this application, when the colorant is mixed with polymer particles, the colorant used has a brightness parameter of 5 to 30, and the mass ratio of the colorant to the polymer particles is 0.1% to 5%. Furthermore, the premix is ​​generally melt-blended in a twin-screw extruder, and the melt-blending temperature is generally in the range of 120°C to 180°C. The foaming molding step is generally performed in a mold, where the masterbatch is foamed to form a pre-set shape, which is beneficial for subsequent layup preparation of wind turbine blades using the molded wind turbine blade core material. This step does not have specific requirements regarding the type of foaming agent, as long as it meets the purpose of this application. As an example, in some embodiments of this application, the foaming agent may include at least one of physical foaming agents and chemical foaming agents; physical foaming agents may include, but are not limited to, at least one of supercritical carbon dioxide, nitrogen, and alkanes, wherein alkanes may include, but are not limited to, at least one of cyclopentane and butane; chemical foaming agents include, but are not limited to, at least one of azodicarbonamide and inorganic carbonates.

[0033] This application also provides a wind turbine blade, which includes a shell with a cavity. A main beam and a web are disposed within the cavity. The main beam is located on the surface of the shell, and the web is vertically arranged with its sidewalls connected to the surface of the shell. The shell includes the aforementioned wind turbine blade core material. Because the wind turbine blade contains the aforementioned wind turbine blade core material, the contrast between defective and non-defective areas of the core material is more pronounced, which can significantly improve the accuracy of defect detection, reduce the missed detection rate and inspection time, and improve both the overall batch quality and production efficiency of the wind turbine blades.

[0034] This application does not specifically limit the production method of wind turbine blades, as long as it meets the purpose of this application. For example, the currently mainstream vacuum infusion process can be used; of course, pultrusion molding technology or prepreg technology can also be used. For ease of understanding, this application uses the vacuum infusion process as an example to illustrate the production process of the wind turbine blade core material of this application embodiment; the production process mainly includes mold preparation, material laying, resin infusion, bonding and assembly, etc., as detailed below: Mold preparation typically involves preparing a wind turbine blade shell mold of a suitable shape based on pre-calculated and preset dimensions. Usually, the wind turbine blade shell mold is divided into two parts, which are then combined to form the entire wind turbine blade. During the demolding process, the shell can easily be damaged, leading to defects such as cracks in the wind turbine blade. Currently, when preparing wind turbine blade shell molds, an anti-adhesion coating is usually applied to the inner surface of the mold, and a release agent is sprayed on it. This reduces the occurrence of defective areas.

[0035] During material laying, glass fiber and the wind turbine blade core material of this embodiment are typically laid alternately in the wind turbine blade shell mold. This allows the wind turbine blade core material to be embedded in the glass fiber, enhancing the structural strength of the formed wind turbine blade. After laying the glass fiber and wind turbine blade core material, a flow guide net and vacuum bag film are also laid to ensure the subsequent resin infusion step can proceed normally. However, the infusion process can easily lead to defects in the formed wind turbine blade; for example, uneven infusion may cause voids, or impurities may be introduced, resulting in defects.

[0036] During resin infusion, a vacuum is first drawn, and then epoxy resin is injected. After the epoxy resin cures and forms a partial shell, a partial shell is obtained. Before the epoxy resin cures, it can be impregnated into the glass fiber and wind turbine blade core material. After the epoxy resin cures, it can reduce the porosity and increase the shell strength.

[0037] During the bonding assembly, not only are the two shell parts glued together to form a complete shell, but components such as the main beam, web, and lead wires are also assembled within the internal cavity of the shell. During assembly, the main beam is attached to the inner surface of the shell, supporting the entire wind turbine blade. The web is vertically positioned within the shell, with its sidewalls contacting the inner surface. The web serves to transfer loads and enhance the overall rigidity of the wind turbine blade, preventing blade deformation. This application does not impose specific requirements on the manufacturing process and materials of the main beam, web, and other components, as long as they meet the objectives of this application.

[0038] This application also provides a method for detecting defects in wind turbine blades. Typically, the method involves first inspecting the core material of the wind turbine blade to identify defective areas; then inspecting the finished wind turbine blade to identify defective areas. The method includes the following steps: S100, Detecting defective areas in the core material of wind turbine blades.

[0039] This step typically involves using a light source to illuminate the core material of the wind turbine blade to obtain a pre-image result, and then determining the defective areas in the core material of the wind turbine blade based on the pre-image result.

[0040] S200, detects defective areas in wind turbine blades.

[0041] After the wind turbine blade is made using the core material of the wind turbine blade (i.e., the wind turbine blade mentioned above), the wind turbine blade is illuminated with a light source to obtain an image result, and the defect area in the wind turbine blade is determined based on the image result.

[0042] In steps S100 and S200, the light intensity, wavelength, and energy of the light source can be the same or different; this application does not impose any particular restrictions on this. However, it should be noted that in steps S100 and S200, the light intensity of the light source cannot be less than 1000 Lux; otherwise, the signal-to-noise ratio will be too low, making it difficult to observe the defect area effectively. After irradiation with a light source with an intensity of not less than 1000 Lux, the grayscale contrast between the defect area and the normal area is quite obvious in the pre-imaging and imaging results, generally exceeding 100:1. Based on this, the core material of the wind turbine blade and the defective areas within the blade can be identified, reducing the missed detection rate and inspection time. This improves both the overall batch quality of wind turbine blades and production efficiency.

[0043] Furthermore, this application does not impose any particular limitations on the wavelength and energy range of the light source, as long as it meets the purpose of this application. As an example, in some embodiments of this application, the wavelength of the light source can be 0.1 nm to 900 nm, which can enhance the contrast of specific defects, such as demolding damage and core material microcracks. The energy of the light source is generally 1.6 eV to 40 eV; too low or too high energy can easily lead to missed detections.

[0044] Furthermore, it should be noted that the equipment used in the detection method of this application can be existing detection equipment; only the light source parameters need to be adjusted accordingly. The wind turbine blade defect detection method of this application embodiment can achieve a defect identification size lower limit of 0.5 mm. Additionally, an image recognition system can be used in the detection equipment to automatically identify and locate defects in the acquired images, improving detection efficiency and accuracy.

[0045] In this application, after the wind turbine blade core material is manufactured into a wind turbine blade, the defective areas in the wind turbine blade core material become more apparent; therefore, compared to step S100, the defect detection in step S200 is more accurate and comprehensive. Thus, in some embodiments of this application, considering work efficiency and detection accuracy, defect detection of the wind turbine blade core material may be omitted, and instead, defect detection of the wind turbine blade itself may be performed directly. As an example, in this embodiment, defect detection is performed only on the wind turbine blade, not on the wind turbine blade core material.

[0046] The technical solution of this application will be described in detail below with reference to the embodiments.

[0047] Test method: The compressive strength test method refers to ISO 844 / ASTM C 365, the peel performance test method refers to ASTM D1781 / GB / T 1457, the tensile strength test method refers to ASTM C 297, and the shear strength test method refers to ISO 1922 / ASTM C 273. Cell diameter is observed using an optical microscope section. The double-sided adhesive absorption test method for flat sheets refers to ISO 845. The equipment used in the test includes: a universal testing machine, an optical microscope, and an electronic balance.

[0048] Defect detection Defect detection of wind turbine blades was performed using an optical microscope to obtain imaging results; the light intensity of the light source during the test was 1000 Lux, the energy was 20 eV, and the wavelength was 400 nm. The manufacturing method of the wind turbine blades is described above in this application.

[0049] When a certain area has a significant grayscale contrast with its surrounding areas, and the grayscale contrast ratio between the surrounding areas and the area in question is not less than 100:1, the area is determined to be a defective area. Then, the wind turbine blades are disassembled, and the accuracy rate of defective area identification is statistically analyzed.

[0050] The test results are shown in Table 1.

[0051] Example 1 This embodiment provides a wind turbine blade core material, comprising a polymer matrix and a colorant uniformly dispersed in the polymer matrix. The colorant has a brightness parameter of 30, an average particle size of 5 μm, and accounts for 0.1% of the polymer matrix mass. The polymer matrix has a density of (100±10) kg / m³. 3 .

[0052] The wind turbine blade core material in this embodiment is manufactured using the following method: A premix is ​​formed by mixing a colorant with polymer particles, wherein the colorant is a brown masterbatch, the polymer particles are PET, the colorant accounts for 0.1% of the mass of the polymer particles, the brightness parameter of the colorant is 30, and the average particle size of the colorant is 5μm.

[0053] The premixed materials are melt-blended at 120°C using a twin-screw extruder to produce masterbatch.

[0054] A foaming agent, cyclopentane, is added to the masterbatch for foaming and molding.

[0055] Example 2 This embodiment provides a wind turbine blade core material, comprising a polymer matrix and a colorant uniformly dispersed in the polymer matrix. The colorant has a brightness parameter of 20, an average particle size of 1 μm, and accounts for 5% of the polymer matrix mass. The polymer matrix has a density of (100±10) kg / m³. 3 .

[0056] The wind turbine blade core material in this embodiment is manufactured using the following method: A premix is ​​formed by mixing a colorant with polymer particles, wherein the colorant is inorganic carbon black, the polymer particles are PET, the colorant accounts for 5% of the mass of the polymer particles, the brightness parameter of the colorant is 20, and the average particle size of the colorant is 1μm.

[0057] The premixed materials are melt-blended at 120°C using a twin-screw extruder to produce masterbatch.

[0058] A foaming agent, cyclopentane, is added to the masterbatch for foaming and molding.

[0059] Example 3 This embodiment provides a wind turbine blade core material, comprising a polymer matrix and a colorant uniformly dispersed in the polymer matrix. The colorant has a brightness parameter of 5, an average particle size of 2 μm, and accounts for 2% of the polymer matrix mass. The polymer matrix has a density of (100±10) kg / m³. 3 .

[0060] The wind turbine blade core material in this embodiment is manufactured using the following method: A premix is ​​formed by mixing a colorant with polymer particles, wherein the colorant is iron(III) oxide, the polymer particles are PET, the colorant accounts for 2% of the mass of the polymer particles, the brightness parameter of the colorant is 5, and the average particle size of the colorant is 2μm.

[0061] The premixed materials are melt-blended at 120°C using a twin-screw extruder to produce masterbatch.

[0062] A foaming agent, cyclopentane, is added to the masterbatch for foaming and molding.

[0063] Comparative Example 1 This comparative example provides a wind turbine blade core material, comprising a density of (100±10) kg / m³. 3 The polymer matrix, which does not contain colorants, is used to prepare the wind turbine blade core material in this comparative example, which is prepared in the following manner: The polymer particles are melt-blended at 120°C using a twin-screw extruder to produce a masterbatch; the polymer particles are PET.

[0064] A foaming agent, cyclopentane, is added to the masterbatch for foaming and molding.

[0065] Comparative Example 2 This comparative example provides a wind turbine blade core material, comprising a polymer matrix and a colorant uniformly dispersed in the polymer matrix, wherein the colorant has a brightness parameter of 30, an average particle size of 5 μm, accounts for 0.08% of the polymer matrix mass, and the polymer matrix has a density of (100±10) kg / m³. 3 .

[0066] The wind turbine blade core material in this comparative example is prepared using the following method: A premix is ​​formed by mixing a colorant with polymer particles, wherein the colorant is a brown masterbatch, the polymer particles are PET, the colorant accounts for 0.08% of the mass of the polymer particles, the brightness parameter of the colorant is 30, and the average particle size of the colorant is 5μm.

[0067] The premixed materials are melt-blended at 120°C using a twin-screw extruder to produce masterbatch.

[0068] A foaming agent, cyclopentane, is added to the masterbatch for foaming and molding.

[0069] Comparative Example 3 This comparative example provides a wind turbine blade core material, comprising a polymer matrix and a colorant uniformly dispersed in the polymer matrix, wherein the colorant has a brightness parameter of 32, an average particle size of 5 μm, accounts for 0.1% of the polymer matrix mass, and the polymer matrix has a density of (100±10) kg / m³. 3 .

[0070] The wind turbine blade core material in this comparative example is prepared using the following method: A premix is ​​formed by mixing a colorant with polymer particles, wherein the colorant is a brown masterbatch, the polymer particles are PET, the colorant accounts for 0.1% of the mass of the polymer particles, the brightness parameter of the colorant is 32, and the average particle size of the colorant is 5μm.

[0071] The premixed materials are melt-blended at 120°C using a twin-screw extruder to produce masterbatch.

[0072] A foaming agent, cyclopentane, is added to the masterbatch for foaming and molding.

[0073] Comparative Example 4 This comparative example provides a wind turbine blade core material, which differs from the wind turbine blade core material of Example 1 in that the colorant accounts for 6% of the polymer matrix mass.

[0074] Application examples Physical images of the wind turbine blade core material in the embodiments of this application and Comparative Example 1 are shown below. Figure 2 As shown, from left to right, these are the wind turbine blade core materials of Example 2, Example 3, Example 1, and Comparative Example 1. Figure 2 As can be seen, compared with wind turbine blade core materials that do not contain colorants, the defects of the wind turbine blade core materials in the embodiments of this application can be detected more obviously.

[0075] Wind turbine blades were fabricated using the wind turbine blade core materials from the embodiments and comparative examples, respectively. The wind turbine blades include a shell, in which a cavity is provided, and a main beam and a web are provided in the cavity. The main beam is located on the surface of the shell, and the web is vertically arranged, with its sidewalls connected to the surface of the shell. The shell contains the wind turbine blade core material.

[0076] Table 1

[0077] After disassembling the wind turbine blades, it was also found that a large number of undetected defect areas existed in the comparative examples. Therefore, as can be seen from the above, in the embodiments of this application, after the wind turbine blade core material is made into wind turbine blades, the defect detection rate of the wind turbine blades is high and it is not easy to miss any defects; in addition, the wind turbine blade core material in the embodiments of this application has high strength, indicating that the wind turbine blade core material of this application can well meet the requirements of wind turbine blades.

[0078] Specifically, as shown in Example 1 and Comparative Example 2, when the colorant content is low, the accuracy of defect area identification decreases significantly, and the detection of defect areas is not comprehensive enough. This indicates that when the colorant content is below 0.1%, the defect areas become indistinct, affecting defect area identification. Specifically, as shown in the test results of Example 1 and Comparative Example 3, when the brightness parameter of the colorant is greater than 30, the accuracy and comprehensiveness of defect area identification decrease significantly. This indicates that excessive colorant brightness affects defect area identification, making it difficult to distinguish defect areas. Specifically, as shown in the test results of Example 1 and Comparative Example 4, when the colorant content is excessive, it has a significant adverse effect on the strength of the wind turbine blade core material.

[0079] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A wind turbine blade core material, characterized in that, include: The polymer matrix and the colorant, wherein the colorant is uniformly dispersed in the polymer matrix, the brightness parameter of the colorant is 5~30, and the mass of the colorant accounts for 0.1%~5% of the mass of the polymer matrix.

2. The wind turbine blade core material according to claim 1, characterized in that, The colorant has an average particle size of 0.5 μm to 5 μm.

3. The wind turbine blade core material according to claim 1, characterized in that, The colorant includes at least one of carbon black, iron oxide, or masterbatch.

4. The wind turbine blade core material according to claim 1, characterized in that, The polymer matrix includes polyethylene terephthalate.

5. The wind turbine blade core material according to claim 1, characterized in that, The density of the polymer matrix is ​​50 kg / m³. 3 ~300kg / m 3 .

6. A wind turbine blade, characterized in that, The device includes a shell, in which a cavity is provided, and a main beam and a web are provided in the cavity. The main beam is located on the surface of the shell, and the web is vertically arranged, with its sidewalls connected to the surface of the shell. The housing comprises the wind turbine blade core material as described in any one of claims 1 to 5.

7. A wind power generation device, characterized in that, It includes a tower body and the wind turbine blade as described in claim 6, wherein the wind turbine blade is located at the top of the tower body.

8. A method for detecting defects in wind turbine blades, characterized in that, Includes the following steps: The wind turbine blade of claim 6 is illuminated by a light source to obtain an imaging result, and the defect area in the wind turbine blade is determined based on the imaging result; the light intensity of the light source is not less than 1000 Lux; the grayscale contrast between the normal area and the defect area is not less than 100:

1.

9. The method for detecting defects in wind turbine blades according to claim 8, characterized in that, The energy of the light source is 1.6 eV to 40 eV; and / or, The wavelength of the light source is 0.1nm~900nm.

10. The method for detecting defects in wind turbine blades according to claim 8, characterized in that, It also includes the following steps: Before irradiating the wind turbine blade, the light source is used to irradiate the core material of the wind turbine blade to obtain a pre-image result. Based on the pre-image result, the defect area in the core material of the wind turbine blade is determined; the grayscale contrast between the normal area and the defect area is not less than 100:

1.

11. The method for detecting defects in wind turbine blades according to any one of claims 8 to 10, characterized in that, The size of the defective area is not less than 0.5 mm.

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