Fiber fabric capable of defect detection, and fan blade having same

Abstract

Disclosed in the present invention is a fiber fabric capable of defect detection. The fiber fabric comprises fibers and braided wires for connecting the fibers together, wherein the braided wires comprise first braided wires in a different color from the fibers, and the distance between any two adjacent first braided wires is set to enable the positioning of wrinkle defects caused by the fabric laying. A product such as a fan blade is manufactured by using the fiber fabric having the first braided wires which are distributed in a high density, so that wrinkle defects can be identified in a timely manner by means of the state of the first braided wires during the laying of the fiber fabric over a large area, and after curing and forming, the defect position and the number of layers involved are positioned by means of the state of the first braided wires, such that destructive detection or maintenance is avoided.

Description

Fiber fabric capable of performing defect detection and fan blade thereof Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a fiber fabric capable of performing defect detection, and a wind turbine blade using the fiber fabric. Background Art

[0002] With the continuous advancement of wind power technology, the megawatt output of wind turbines has continued to increase. This has led to a continuous increase in the diameter of wind turbine rotors, or in other words, blade length. This increase in blade length inevitably increases blade weight. However, due to the performance limitations of wind turbine hubs, towers, and other components, the actual manufacturing process imposes certain weight limits on wind turbine blades, making blade weight a bottleneck in increasing the megawatt output of wind turbines.

[0003] To reduce the weight of wind turbine blades, glass fiber fabric is currently commonly used in the blade shells through layering and infusion molding. Laying the fabric over a large area can cause wrinkles in the fabric, which can induce subtle bending deformations in the compressed blade shell. This can gradually spread, eventually leading to cracks throughout the blade shell's thickness. Therefore, timely detection of wrinkle defects during the manufacturing process is crucial for improving wind blade production quality.

[0004] However, the glass fiber and its braid used in wind turbine blade manufacturing are currently white, requiring specialized equipment to detect defects. As blade size increases, the time required to detect wrinkles in or out of the glass fiber fabric increases significantly, resulting in low detection efficiency. Furthermore, locating wrinkles that appear during the infusion and curing process requires complete sanding of the fabric layer above the wrinkle, which can cause irreparable damage.

[0005] Summary of the Invention

[0006] In response to some or all of the problems in the prior art, the present invention provides, on one hand, a fiber fabric capable of defect detection, which includes a first weaving line of a different color from the fiber, and the distance between two adjacent first weaving lines is set so as to enable the location of wrinkle defects caused by the fabric layup.

[0007] Furthermore, the relative color difference between the first braided wire and the fiber color is not less than 3, wherein the relative color difference is calculated based on color parameters output according to the color model published by CIELAB in 1976.

[0008] Furthermore, the first braided wire has one or more colors.

[0009] Furthermore, the number of colors of the first braided wire does not exceed 20.

[0010] Furthermore, the fiber fabric also includes a second braided thread having the same color as the fiber.

[0011] Furthermore, the ratio of the first braided wire to the second braided wire is 1:10 to 1:500.

[0012] Furthermore, the ratio of the first braided wire to the second braided wire is 1:10 to 1:100.

[0013] Furthermore, the ratio of the first braided wire to the second braided wire is 1:10 to 1:50.

[0014] Furthermore, the braided wire is arranged along the 0° direction of the fiber fabric.

[0015] Furthermore, the distance between any two adjacent first braiding lines is 11 to 501 times the width of the odd yarn bundle.

[0016] Furthermore, the distance between any two adjacent first braided wires is 11 to 101 times the width of the odd yarn bundle.

[0017] Furthermore, the distance between any two adjacent first braiding lines is 11 to 51 times the width of the odd yarn bundle.

[0018] Furthermore, the braided wire is glass fiber or polyester fiber.

[0019] Furthermore, the fiber fabric is a uniaxial, biaxial, or triaxial glass fiber fabric, which includes main direction and / or weft direction glass fibers, and the color of the glass fibers is white.

[0020] Furthermore, the fiber fabric is woven in a warp-plain, variable-warp-plain, double-variable-warp-plain or chain-knitted manner.

[0021] Based on the fiber fabric as described above, the present invention provides a wind blade on the other hand, at least one component of the wind blade includes the fiber fabric as described above, and the distance between two adjacent first weaving lines in the fiber fabric is set to enable locating wrinkle defects of the wind blade.

[0022] Furthermore, the colors of the first braided threads contained in each layer of fiber fabric in the fan blade are different.

[0023] Based on this, the present invention also provides a method for detecting defects in wind turbine blades, comprising:

[0024] During the laying of the fiber fabric, determining the conformability and straightness of the fiber fabric by observing the direction of the first braiding lines; and / or

[0025] After the fan blade is injection molded, the direction of the first braiding line in the span direction of the fan blade is observed to determine whether a wrinkle defect exists and locate the defect position.

[0026] Furthermore, the defect detection method also includes automatically identifying paving defects through an image recognition system.

[0027] Based on this, the present invention further provides an image recognition system for detecting defects in a wind turbine blade, wherein the wind turbine blade comprises the fiber fabric as described above, and the defect detection comprises:

[0028] During the laying of the fiber fabric, determining the conformability and straightness of the fiber fabric by judging the direction of the first braiding line; and / or

[0029] After the fan blade is cast, the direction of the first braiding line in the span direction of the fan blade is judged to determine whether there is a wrinkle defect and locate the defect position, wherein the defect position includes the position where the first braiding line is bent or wrinkled.

[0030] The present invention is based on the inventors' insight that existing methods for detecting the curvature of wind turbine blades fall into two categories: non-destructive and destructive testing. Non-destructive testing methods primarily include X-rays, ultrasound, acoustic emission, light sensors, and thermal infrared imaging. However, these methods all have limitations, including being unsuitable for on-site testing, poor accuracy, and inefficient stability. Research has revealed that defects in wind turbine blades are often caused by wrinkles in the fabric produced during the manufacturing process. However, because the glass fibers and their braiding yarns used in existing wind turbine blade fabrics are all white, wrinkle detection during manufacturing is extremely difficult and inefficient. Based on this, the present invention provides a fiber fabric capable of defect detection. The fabric replaces some or all of the white braiding yarns in existing fabrics with colored braiding yarns. This allows the curvature of the fabric to be identified and the presence of wrinkles to be confirmed during large-scale fabric installation. Furthermore, after the wind turbine blade is cast, the colored braiding yarns can be visually observed from the outside of the blade to accurately identify and locate the defect and the number of layers involved, thereby avoiding extensive, destructive repairs required for troubleshooting. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] To further illustrate the above and other advantages and features of various embodiments of the present invention, a more detailed description of various embodiments of the present invention will be presented with reference to the accompanying drawings. It will be understood that these drawings depict only typical embodiments of the present invention and are not to be considered as limiting the scope thereof. In the drawings, for clarity, identical or corresponding components will be represented by the same or similar reference numerals.

[0032] FIG1 is a schematic structural diagram of a fiber fabric capable of performing defect detection according to an embodiment of the present invention; and

[0033] FIG2 is a schematic structural diagram of a fan blade to which the present invention is applied. DETAILED DESCRIPTION

[0034] In the following description, the present invention is described with reference to various embodiments. However, those skilled in the art will recognize that the various embodiments can be implemented without one or more of the specific details or with other alternative and / or additional methods, materials, or components. In other cases, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring the inventive aspects of the present invention. Similarly, for the purpose of explanation, specific quantities, materials, and configurations are described to provide a comprehensive understanding of the embodiments of the present invention. However, the present invention is not limited to these specific details. In addition, it should be understood that the various embodiments shown in the drawings are illustrative representations and are not necessarily drawn to scale.

[0035] In the present invention, unless otherwise specified, the phrases "disposed on," "disposed above," and "disposed above" do not exclude the presence of intermediate components. Furthermore, "disposed on or above" merely indicates the relative positional relationship between two components and, in certain circumstances, such as after reversing the product orientation, can be converted to "disposed below or below," and vice versa.

[0036] In the present invention, unless otherwise specified, the quantifiers "a" and "an" do not exclude the presence of multiple elements.

[0037] It should also be noted that, within the scope of the present invention, terms such as "same," "equal," and "equal to" do not imply absolute equality of values, but rather allow for a certain reasonable error. In other words, such terms also encompass "substantially the same," "substantially equal," and "substantially equal." Similarly, in the present invention, terms such as "perpendicular to" and "parallel to" indicating direction also encompass the meaning of "substantially perpendicular to" and "substantially parallel to."

[0038] It should be noted that the embodiments of the present invention describe the process steps in a specific order. However, this is only for the purpose of illustrating the specific embodiment and does not limit the order of the steps. On the contrary, in different embodiments of the present invention, the order of the steps can be adjusted according to the process.

[0039] To address the problem of low efficiency in existing wind turbine blade defect detection, which may require destructive repair or inspection, the present invention provides a fiber fabric capable of defect detection. The fiber fabric replaces some or all of the white braided threads in the existing fiber fabric with colored braided threads. This allows the curvature of the fiber fabric to be visually identified and wrinkles to be confirmed during large-scale fiber fabric laying, greatly improving detection efficiency. Furthermore, after the wind turbine blade is cast, the colored braided threads can still be directly observed from the outside of the blade by the naked eye, allowing for rapid identification and accurate location of defects and the number of designed layers, thereby avoiding destructive repair or inspection. For this reason, in the present invention, the colored braided threads can also be referred to as color threads or tracer threads.

[0040] It should be understood that the fiber fabric can also be applied to other products formed by fiber fabric layering and infusion molding, and the principles of defect detection and positioning are the same as those in wind turbine blades.

[0041] The solution of the present invention is further described below in conjunction with the accompanying drawings of the embodiments.

[0042] FIG1 shows a schematic structural diagram of a fiber fabric capable of defect detection according to an embodiment of the present invention. As shown in FIG1 , a fiber fabric capable of defect detection comprises a fiber 101, and braided threads 121 and 122 for sewing the fibers 101 together, wherein the braided threads comprise a first braided thread 121 of a different color from the fibers 101. Due to the provision of the first braided thread 121, when the fiber fabric is applied to the manufacture of wind turbine blades, defects such as wrinkles can be accurately and quickly identified by visual observation during the laying process and after curing and molding. In order to better identify and locate defects, in an embodiment of the present invention, the spacing between any two adjacent first braided threads is set within a range less than the wrinkle acceptability, thereby enabling wrinkles exceeding the wrinkle acceptability to be identified by visually observing the straightness of the two adjacent first braided threads. In one embodiment of the present invention, when the width of a single yarn bundle of the fiber fabric is N mm, the distance between any two adjacent first braiding threads 121 is set to 11N to 501N mm, preferably set to be within the range of 11N to 101N mm, and more preferably set to be within the range of 11N to 51N mm. At the same time, in order to better identify the first braiding thread with the naked eye, the color of the first braiding thread is preferably a color that contrasts strongly with the fiber. In one embodiment of the present invention, the relative color difference between the first braiding thread and the fiber color is not less than 3, wherein the relative color difference is calculated based on the color parameters output by the color model published by CIELAB in 1976.

[0043] In an embodiment of the present invention, the fiber fabric may be a uniaxial, biaxial, or triaxial glass fiber fabric or other types of fiber fabric. The fiber fabric may include only main direction fibers, or may further include weft fibers. The main direction fibers refer to fibers that are parallel and evenly arranged along the length direction of the blade, i.e., in the 0° direction, and the weft fibers are at an angle to the main direction fibers and are substantially parallel to the width direction of the wind turbine blade. At the same time, in one embodiment of the present invention, the main direction fibers and the weft fibers are sewn together by braiding wire using, for example, warp-plain, variable-warp-plain, double-variable-warp-plain, or chain-weaving methods.

[0044] In one embodiment of the present invention, the main direction fibers and / or weft direction fibers are glass fibers. Glass fibers are usually white, so in one embodiment of the present invention, the first braided wire only needs to be non-white.

[0045] In one embodiment of the present invention, the braided wire sews the main direction fibers and the weft direction fibers together in a warp-flat manner, that is, the braided wire is arranged along the 0° direction of the fiber fabric. Based on this, in one embodiment of the present invention, the braided wire can be made of inorganic fibers such as glass fibers, and in another embodiment of the present invention, the braided wire can be made of other synthetic organic fibers such as polyester fibers. There is no limit to the surface density, linear density and stitch length of the braided wire, but in order to optimize the weaving parameters of the fiber fabric, thereby increasing the fiber volume content of the wind turbine blades and reducing the amount of resin used, in one embodiment of the present invention, the linear density of the braided wire is preferably not greater than 150D, and / or the stitch length of the braided wire is preferably not greater than 5mm.

[0046] In an embodiment of the present invention, the color types of the first braiding wire contained in the same fiber fabric may be one or more. However, if braiding wires of too many colors are used, the color of the fiber fabric may be too mixed, which is not conducive to defect detection. Therefore, in one embodiment of the present invention, the color types of the first braiding wire contained in the same fiber fabric do not exceed 20, and preferably are 1.

[0047] Similarly, if the density of the first braided wire is too high, it is not conducive to defect detection by the naked eye in certain large-area laying processes. Therefore, in one embodiment of the present invention, a certain amount of second braided wire 122 of the same color as the fiber 101 is still retained in the fiber fabric. The ratio of the first braided wire to the second braided wire can be determined, for example, by the area of ​​the wind turbine blade to be manufactured. In one embodiment of the present invention, the ratio of the first braided wire to the second braided wire is set between 1:10 and 1:500. Preferably, the ratio of the first braided wire to the second braided wire is set between 1:10 and 1:100. More preferably, the ratio of the first braided wire to the second braided wire is set between 1:10 and 1:50.

[0048] The fiber fabric described above can be used to manufacture wind turbine blade shells. FIG2 shows a schematic structural diagram of a wind turbine blade to which the present invention is applied. As shown in FIG2 , a wind turbine blade includes a leading edge 201, main beams 221 and 222, a pressure surface 203, a suction surface 204, and a trailing edge 205. Furthermore, two webs 261 and 262 are fixed between the two main beams 221 and 222. Any of the main beams, webs, pressure surfaces, suction surfaces, and tail beams can be manufactured using the fiber fabric of the embodiments of the present invention through layup and infusion molding.

[0049] The fan blade housing typically comprises multiple layers of fiber fabric. To facilitate locating the layer where a wrinkle defect occurs, in one embodiment of the present invention, first braided threads of different colors are provided within each layer of the fiber fabric. This arrangement allows for rapid location of the defective layer based solely on the color of the braided thread where the bend or wrinkle is present. Furthermore, the density of the first braided threads within each layer of the fiber fabric can also vary.

[0050] By providing colored braided wires, the defect detection of the wind turbine blades as described above may include:

[0051] First, in the process of laying the fiber fabric, the direction of the first braiding line can be observed with the naked eye, and the conformability and straightness of the fiber fabric can be intuitively obtained. Specifically, under normal conditions, two adjacent first braiding lines should be basically parallel, or the straightness is basically the same. Since the gap between the two adjacent first braiding lines is smaller than the acceptable wrinkle width, once wrinkles exceeding the width appear, the straightness of the two adjacent first braiding lines will inevitably be affected, and intersections may occur. Based on this, it is only necessary to observe whether there is an intersection of the first braiding lines to quickly identify whether wrinkles occur. In one embodiment of the present invention, a simple image recognition system can also be set up to achieve linkage with the monitoring system, and then automatically identify laying defects; during the defect detection process, the laying operation can be carried out synchronously without interruption;

[0052] Secondly, after the fan blade is cast, the direction of the first braiding line in the span direction of the fan blade can be observed from the outside of the blade by visual observation or linkage with a monitoring system as described above, and whether there is a wrinkle defect can be determined, thereby locating the defect without polishing above the wrinkle, which would cause irreparable damage; and

[0053] Finally, in a wind farm, defect detection and positioning can still be achieved through the colored braided wire.

[0054] In order to verify the effect of the fiber fabric, a warp-knitted biaxial 600 fiber fabric was used to manufacture fan blades, and the acceptable standard for wrinkles on the fan blades was less than 250mm. The width of the fiber fabric is 1270mm, including a first braided wire and a second braided wire made of 100D polyester. The color of the first braided wire is purple, and the color of the second braided wire is consistent with the fiber, which is white. The spacing between two adjacent first braided wires is about 150mm, which is less than the acceptable standard for wrinkles. It can be calculated that at this width, there are a total of 9 first braided wires, and the ratio of the first braided wire to the second braided wire is 1:23. When the fiber fabric is used for laying, when the wrinkles exceed the range between two adjacent first braided wires, it is considered to be a defect that needs to be repaired. After testing, compared with fiber fabrics without colored braided wires, the detection time for wrinkles and straightness can be saved by 0.5 to 1 hour.

[0055] In order to further verify the defect positioning effect after infusion molding, 9 different types of fiber fabrics were further used to manufacture wind turbine blades, wherein the length of the wind turbine blades was 76m. The different types of fiber fabrics have different gram weights and / or impregnation agents and / or weaving directions and / or fabric axes, and each type of fabric weaving wire includes a first weaving wire of a non-white color and a second weaving wire of white color, and each first weaving wire has a different color. Therefore, the wind turbine blade contains a total of 9 colors of first weaving wires. After the wind turbine blades are molded and demolded, after testing, it can still be accurately located to the number of layers and fabric types of defects such as wrinkles by the color of the weaving wires, either by the naked eye or in conjunction with the monitoring system, thereby quickly realizing defect positioning and detection without causing irreparable damage, which greatly helps blade inspection and repair.

[0056] In addition, after testing, it was found that defects of the wind turbine blades can still be detected and located in a wind field through the colored braided wire.

[0057] Although various embodiments of the present invention have been described above, it should be understood that they are presented by way of example only and not limitation. It will be apparent to those skilled in the relevant art that various combinations, modifications, and variations may be made thereto without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the present invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined solely in accordance with the appended claims and their equivalents.

Claims

1. A fiber fabric capable of defect detection, characterized in that: include: fibers configured to function as fibers in a fabric layup; as well as A plurality of braiding threads are configured to connect the fibers together, wherein the braiding threads are arranged parallel to each other and include first braiding threads of a different color from the fibers, wherein a distance between two adjacent first braiding threads is set to enable locating wrinkle defects formed in the fabric ply.

2. The fiber fabric according to claim 1, characterized in that The distance between two adjacent first braiding lines is 11 to 501 times the width of the odd yarn bundle.

3. The fiber fabric according to claim 1, wherein The distance between two adjacent first braiding lines is 11 to 101 times the width of the odd-numbered yarn bundle.

4. The fiber fabric according to claim 1, wherein The distance between two adjacent first braiding lines is 11 to 51 times the width of the odd yarn bundle.

5. The fiber fabric according to claim 1, characterized in that The relative color difference between the first braided wire and the fiber color is not less than 3, wherein the relative color difference is calculated based on color parameters output by the color model published by CIELAB in 1976.

6. The fiber fabric according to claim 1, characterized in that The first braided wire has one or more colors.

7. The fiber fabric according to claim 1, characterized in that The number of colors of the first braided wire does not exceed 20.

8. The fiber fabric according to claim 1, wherein: The braided wire also includes a second braided wire of the same color as the fiber.

9. The fiber fabric according to claim 8, characterized in that The ratio of the first braided wire to the second braided wire is 1:10 to 1:

500.

10. The fiber fabric according to claim 8, characterized in that The ratio of the first braided wire to the second braided wire is 1:10 to 1:

100.

11. The fiber fabric according to claim 8, characterized in that The ratio of the first braided wire to the second braided wire is 1:10 to 1:

50.

12. The fiber fabric according to claim 1, wherein The braided wires are arranged along the 0° direction of the fiber fabric.

13. The fiber fabric according to claim 1, wherein The braided wire is glass fiber or polyester fiber.

14. The fiber fabric according to claim 1, wherein It is a uniaxial, biaxial, or triaxial glass fiber fabric, which includes main direction and / or weft direction glass fibers, and the color of the glass fibers is white.

15. The fiber fabric according to claim 1, wherein It is woven in plain warp, variable warp plain, double variable warp plain or chain braiding methods.

16. A fan blade, characterized in that: At least one component thereof comprises the fiber fabric according to any one of claims 1 to 15, wherein: The fibers are configured to function as fibers in a wind blade layup; and The distance between two adjacent first braiding lines is set so as to enable locating wrinkle defects in the wind blade.

17. The fan blade according to claim 16, wherein: The fiber fabric comprises multiple layers, and the first braided threads contained in each layer of the fiber fabric have different colors.

18. A method for detecting defects in a wind turbine blade, wherein the wind turbine blade comprises the fiber fabric according to any one of claims 1 to 15, characterized in that: include: During the laying of the fiber fabric, the conformability and straightness of the fiber fabric are determined by observing the direction of the first braiding line; and / or After the fan blade is cast by injection, the presence of a wrinkle defect is determined by observing the direction of the first braiding line in the span direction of the fan blade, and the defect position is located, wherein the defect position includes the position where the first braiding line is bent or wrinkled.

19. The defect detection method according to claim 18, wherein: Also includes: Automatic identification of laying defects through image recognition system.

20. An image recognition system, characterized in that: It is configured to detect defects of a wind turbine blade, wherein the wind turbine blade comprises the fiber fabric according to any one of claims 1 to 15, and the detection of the defects comprises: During the laying of the fiber fabric, determining the conformability and straightness of the fiber fabric by judging the direction of the first braiding line; and / or After the fan blade is cast, the direction of the first braiding line in the span direction of the fan blade is judged to determine whether there is a wrinkle defect and locate the defect position, wherein the defect position includes the position where the first braiding line is bent or wrinkled.

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