Molding method of wind power blade and wind power blade

Abstract

The invention discloses a forming method of a wind power blade and the wind power blade, and the forming method of the wind power blade comprises the steps that stress reducing treatment is conducted on the target edge of a fiber fabric, and the stress reducing treatment comprises thickness reducing treatment and / or fiber cutting-off continuity treatment; laying the fiber fabric in the skin mold along the target direction to form a fiber fabric staggered layer; injecting resin, and curing to form a skin; and the skin and other blade components are bonded to the blade body, and the wind power blade is formed. The problem that in the prior art, wind power blades are large in stress concentration is solved. According to the embodiment of the invention, at least one operation of thickness reduction and fiber continuity cutting is carried out on the edge of the fiber fabric, so that the stress concentration effect caused by sudden ending of the tail end of the fiber bundle can be reduced, the stress concentration level of the edge of the fiber fabric can be obviously reduced, the local stress concentration of the wind power blade is further reduced, and the service life of the wind power blade is prolonged. And the fatigue resistance of the wind power blade can be obviously improved.

Description

Technical Field

[0001] The present application relates to a wind turbine blade, and in particular to a wind turbine blade forming method and a wind turbine blade. Background Art

[0002] Wind turbine blades are the core components of wind turbines. Their main function is to convert natural wind energy into electrical energy for wind turbines. Specifically, wind turbine blades capture wind energy and convert it into mechanical energy, which further drives the generator to generate electricity. The design and manufacture of blades have a crucial impact on the performance and efficiency of wind turbines.

[0003] The shape and size of wind turbine blades directly affect the speed and output power of wind turbines. Common wind turbine blade shapes include straight airfoil, curved airfoil and twisted airfoil. Among them, straight airfoil blades have lower manufacturing costs and maintenance costs, but their performance at high wind speeds is poor, fatigue cracks are prone to occur, and the noise is relatively large. Curved airfoil blades and twisted airfoil blades can provide higher wind energy conversion efficiency at different wind speeds, but their manufacturing and maintenance costs are relatively high.

[0004] As wind turbines continue to grow in size, the size of corresponding wind turbine blades is also increasing. The wind turbine blades are more affected by stress concentration and their fatigue resistance is reduced. Summary of the invention

[0005] The embodiments of the present application provide a method for forming a wind turbine blade and a wind turbine blade, which can reduce local stress concentration of the wind turbine blade and improve fatigue resistance of the wind turbine blade.

[0006] In a first aspect, the present application provides a method for forming a wind turbine blade, comprising:

[0007] Performing stress relief treatment on the target edge of the fiber fabric, wherein the stress relief treatment includes thickness reduction treatment and / or fiber continuity cutting treatment;

[0008] Laying the fiber fabric in the skin mold along the target direction, and retracting and displacing the fiber fabric at the end sides in the axis direction of adjacent layers to form a staggered layer of fiber fabric;

[0009] Laying the molding material on the staggered layers of the fiber fabric, injecting resin, and curing to form a skin;

[0010] The skin and other blade components are bonded to the blade body to form a wind turbine blade.

[0011] According to the method for forming a wind turbine blade according to an embodiment of the present application, the step of reducing the thickness of the target edge of the fiber fabric includes:

[0012] The target edge is cut along the direction from the inside to the outside of the target edge, so that the thickness of the target edge shows a decreasing trend.

[0013] According to the method for forming a wind turbine blade in an embodiment of the present application, the process of cutting the target edge of the fiber fabric to ensure the continuity of the fibers includes:

[0014] Along the length direction of the target edge, shearing the target edge within the width range into a serrated shape;

[0015] Alternatively, the target edge is broken up;

[0016] Alternatively, the target edge is roughened.

[0017] According to the forming method of the wind turbine blade of the embodiment of the present application, when preparing the fiber fabric staggered layer of the blade root, the target edge of the fiber fabric is subjected to stress relief treatment; the fiber fabric is laid in the skin mold along the target direction, and the fiber fabric on the end side in the direction of the axis of adjacent layers is retracted and staggered to form the fiber fabric staggered layer, including:

[0018] Performing stress relief treatment on at least one edge of the fiber fabric in the width direction;

[0019] The fiber fabric is laid in the skin mold along a width direction parallel to the axis of the skin mold, the fiber fabrics on the end sides of the axis direction of adjacent layers are retracted and staggered, and the fiber fabrics are laid circumferentially on the skin mold in the length direction to form staggered fiber fabric layers of the blade.

[0020] According to the forming method of the wind turbine blade of the embodiment of the present application, when preparing the fiber fabric staggered layer of the beam, the target edge of the fiber fabric is subjected to stress relief treatment; the fiber fabric is laid in the skin mold along the target direction, and the fiber fabric on the end side in the direction of the axis of adjacent layers is retracted and staggered to form the fiber fabric staggered layer, including:

[0021] Performing stress relief treatment on at least one side edge of the fiber fabric in the length direction;

[0022] The fiber fabric is laid in the skin mold along a direction parallel to the axis of the skin mold, and the fiber fabrics on the end sides of the axis direction of adjacent layers are retracted and staggered to form staggered fiber fabrics of the beam.

[0023] According to the forming method of the wind turbine blade of the embodiment of the present application, the fiber fabric is laid in the skin mold along the target direction, and the fiber fabrics on the end sides in the axis direction of adjacent layers are retracted and staggered to form a fiber fabric staggered layer, including:

[0024] Cutting the fiber fabric after the stress relief treatment into specified sizes to obtain a fabric block;

[0025] Overlapping the fabric blocks along the axial direction to form a fabric block layer;

[0026] The plurality of fabric blocks are stacked and connected, and the two ends of the two adjacent fabric blocks in the axial direction are retracted and staggered to form a stitched block;

[0027] The stitching blocks are laid in a skin mould along a target direction to form staggered layers of fibre fabric.

[0028] In a second aspect, the present application further provides a wind turbine blade, comprising:

[0029] The skin comprises a fiber fabric staggered layer, wherein the fiber fabric staggered layer comprises a plurality of fiber fabric sheets, the end sides of adjacent fiber fabric sheets are retracted and staggered to be connected, the fiber fabric sheets comprise overlapping fiber fabrics, the fiber fabrics have stress-reducing edges, and the stress of the stress-reducing edges is less than the stress of the fiber fabric edges in an initial state;

[0030] The blade body, the skin is bonded to the surface of the blade body.

[0031] According to the wind turbine blade provided in the embodiment of the present application, the thickness of the stress reducing edge gradually becomes thinner from the inside to the outside.

[0032] According to the wind turbine blade provided by the embodiment of the present application, the stress reducing edge includes a tooth structure.

[0033] According to the wind turbine blade provided in the embodiment of the present application, the width of the stress reducing edge ranges from 0.5 mm to 50 mm.

[0034] The forming method and wind turbine blade of the embodiment of the present application can reduce the stress concentration effect caused by the sudden end of the fiber bundle by performing at least one of operations of reducing the thickness and cutting the fiber continuity on the edge of the fiber fabric, so that the stress concentration level at the edge of the fiber fabric can be significantly reduced, thereby reducing the local stress concentration of the wind turbine blade, and can significantly improve the fatigue resistance of the wind turbine blade, thereby extending the service life of the wind turbine blade, reducing the weight of the wind turbine blade, and thus reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0036] Figure 1A schematic diagram of the structure of a fiber fabric after stress relief treatment provided by some embodiments of the present application is shown;

[0037] Figure 2 A cross-sectional view of a fiber fabric obtained by beveling treatment provided in some embodiments of the present application is shown;

[0038] Figure 3 A cross-sectional view of a fiber fabric obtained by step-cutting treatment provided in some embodiments of the present application is shown;

[0039] Figure 4 One of the structural schematic diagrams showing a fiber fabric provided by some embodiments of the present application with a target edge being toothed;

[0040] Figure 5 A second schematic diagram showing a structure in which a target edge of a fiber fabric provided by some embodiments of the present application is toothed;

[0041] Figure 6 One of the flow charts of a method for forming a wind turbine blade provided in some embodiments of the present application is shown;

[0042] Figure 7 One of the schematic diagrams of the skin mold structure provided by some embodiments of the present application is shown;

[0043] Figure 8 A cross-sectional view of a fiber fabric staggered according to some embodiments of the present application is shown;

[0044] Fig. 9 A second flow chart of a method for forming a wind turbine blade provided in some embodiments of the present application is shown;

[0045] Fig.10 A third flow chart of a method for forming a wind turbine blade provided in some embodiments of the present application is shown;

[0046] Fig.11 A second schematic diagram of a skin mold structure provided by some embodiments of the present application is shown;

[0047] Fig.12 A fourth flow chart of a method for forming a wind turbine blade provided in some embodiments of the present application is shown;

[0048] Fig.13 A schematic structural diagram of a fabric block provided in some embodiments of the present application is shown.

[0049] Reference numerals: 100, fiber fabric; 101, main body area; 102, target edge; 103, first boundary line; 104, second boundary line; 110: fabric block; 200, fiber fabric staggered layer; 201, stitching block; 300: skin mold. DETAILED DESCRIPTION

[0050] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0051] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0052] The following is a brief introduction to the structure of a wind turbine blade to better understand the present application. The structure of a wind turbine blade can be subdivided into several key components, each of which has its own unique function and composition. The following is a detailed explanation of these components:

[0053] Skin: The skin is the main external structure of the wind turbine blade, which is used to capture wind energy. The existing skin is mainly composed of glass fiber fabric, core material and resin. The glass fiber fabric provides the structural strength and rigidity of the blade, while the core material is used to fill and enhance the overall performance of the structure. Resin is used to bond the glass fiber fabric and core material together to form a strong composite structure. The skin is covered on the outside of the beam system and the blade root system.

[0054] Beam system: The main function of the beam system is to effectively transfer the wind energy load captured on the skin to the blade root and support the overall structure of the blade. The beam system includes the main beam, the trailing edge beam and the web. The main beam is the most critical load-bearing component in the wind turbine blade. The skin outside the main beam is usually composed of glass fiber or carbon fiber fabric and resin to provide high-strength and high-modulus support. The trailing edge beam is located at the trailing edge of the blade. The skin of the trailing edge beam is also composed of fiber fabric and resin, which is mainly used to support the trailing edge structure and transfer loads. The web is located between the main beam and the trailing edge beam. The skin outside the web is usually composed of glass fiber resin. The web also includes a core material, which is used to connect the main beam and the trailing edge beam and enhance the overall stiffness of the blade.

[0055] Blade root system: The blade root system is the connection between the wind turbine blade and the hub, which is used to smoothly transfer the wind energy captured by the blade to the hub and support the weight of the entire blade. The outer skin of the blade root system is generally composed of glass fiber and resin, and the blade root system also includes blade root metal connectors. Glass fiber and resin provide structural strength and rigidity, while metal connectors are used to firmly connect the blade to the hub.

[0056] The above components together constitute the overall structure of the wind turbine blade, and each part plays a vital role. With the continuous development of wind power technology, the structure of wind turbine blades is also constantly optimized and innovated to improve wind energy conversion efficiency, reduce blade weight and cost, and enhance blade durability and safety.

[0057] As the demand for electricity from wind power increases, wind turbines are expanding, and the size of wind turbine blades is also growing to accommodate greater wind energy capture and higher energy conversion efficiency. However, this size increase also brings about an increase in blade weight and cost, as well as design and manufacturing challenges. In the design of wind turbine blades, especially in key areas such as the blade root system, how to balance strength, weight, cost and manufacturing efficiency has become an urgent problem to be solved.

[0058] First of all, the blade root system is the main area of ​​the blade that bears bending loads, and its design is critical to the overall performance of the blade. In order to withstand these loads, engineers usually choose to use thicker axial glass fiber fabrics as the skin of the blade root system. However, too thick fiber fabrics will not only increase the weight of the blade, but may also cause stress concentration problems, thereby reducing the durability and safety of the blade.

[0059] To solve this problem, engineers have adopted a variety of strategies. A common approach is to perform axial staggered transitions on the glass fiber fabric to reduce stress concentration caused by thickness mutations. This strategy can alleviate the problem of stress concentration to a certain extent, but it cannot completely eliminate it.

[0060] In addition, with the advancement of technology, the thickness of a single layer of glass fiber fabric is gradually decreasing. Although thinner fiber fabrics have weaker stress concentration at the end of each layer of fiber fabric, this will also increase the number of layers, thus affecting production efficiency. In order to solve this contradiction, some innovative methods have been proposed, such as sewing multiple layers of fiber fabric together before laying them, thereby ensuring strength while improving production efficiency.

[0061] However, with the extensive use of ultra-high modulus glass fiber fabrics on wind turbine blades, even with thin fiber fabrics, the stress concentration level at the ends may be difficult to meet the design and use requirements of wind turbine blades. This is because although ultra-high modulus glass fiber fabrics have higher strength and stiffness, their end stress also increases accordingly, and when ultra-high modulus glass fiber fabrics are used in wind turbine blades, the end steps are more likely to cause stress concentration at the end protrusions, resulting in damage.

[0062] Based on the problems found in the above-mentioned prior art, the present application mainly deals with the stress concentration problem caused by the fiber fabric in the skin system. For fiber fabric of a certain width, a certain range of treatment is performed on the edge in the width direction or the edge in the length direction to alleviate the stress concentration at the end of the fiber fabric, thereby reducing the stress concentration level at the end of the fiber fabric, thereby improving the fatigue resistance of the skin system, and then improving the overall fatigue resistance of the wind turbine blade and reducing cracking.

[0063] In order to solve the problems in the prior art, the embodiment of the present application provides a method for forming a wind turbine blade and a wind turbine blade. The fiber fabric provided in the embodiment of the present application is first introduced below.

[0064] Figure 1 A schematic structural diagram of a fiber fabric after stress relief treatment provided in some embodiments of the present application is shown.

[0065] like Figure 1 As shown, one embodiment of the present application provides a fiber fabric 100, comprising: a main body region 101 and a target edge 102, wherein the target edge 102 is located at an adjacent side of the main body region 101, and the thickness of the target edge 102 is less than the thickness of the main body region 101 and / or the fiber continuity of the target edge 102 is lower than the fiber continuity of the main body region 101. For the target edge 102 of the fiber fabric 100, the fiber fabric 100 in an independent block comprises two side edges opposite to each other in the length direction and two side edges opposite to each other in the width direction, and the target edge 102 in the present application is any one or more side edges mentioned above.

[0066] Specifically, the main body region 101 of the fiber fabric 100 is its main component, occupying most of the area of ​​the fiber fabric 100. The main body region 101 has the main physical and chemical properties of the fiber fabric 100, such as strength, wear resistance, softness, etc. The target edge 102 is located on the adjacent side of the main body region 101, that is, the target edge 102 surrounds or is close to the boundary of the main body region 101. Compared with the main body region 101, the target edge 102 has a smaller thickness or the fiber continuity of the target edge 102 is lower. Of course, the thickness and fiber continuity of the target edge 102 can be both smaller than the main body region 101. The stress concentration of the target edge 102 can be reduced, because the thinner target edge 102 is easier to bend and deform, thereby reducing the stress concentration and cracking phenomenon that may occur when subjected to external force, and improving the fatigue resistance and durability of the fiber fabric 100.

[0067] Specifically, since the stress concentration phenomenon at the target edge 102 is alleviated, the fiber fabric 100 is less likely to crack or break at the target edge 102 when subjected to external force. At the same time, this design can also reduce the material design safety factor, reduce material consumption, and thus reduce production costs.

[0068] Figure 2 A cross-sectional view of a fiber fabric obtained by beveling treatment provided in some embodiments of the present application is shown; Figure 3 A cross-sectional view of a fiber fabric obtained by step-cutting treatment provided in some embodiments of the present application is shown; Figure 4 One of the structural schematic diagrams showing a fiber fabric provided by some embodiments of the present application with a target edge being toothed; Figure 5 A second schematic diagram of a structure in which a target edge of a fiber fabric provided by some embodiments of the present application is toothed is shown.

[0069] like Figures 2 to 5 As shown, the present application provides a fiber fabric processing method, and the fiber fabric mentioned in the above embodiment can be processed by the following method, specifically including: performing stress relief treatment on the target edge 102 of the fiber fabric 100, and the stress relief treatment includes at least one operation of reducing thickness and cutting off fiber continuity; wherein, the target edge 102 includes a first boundary line 103 and a second boundary line 104, and the stress relief treatment is performed between the first boundary line 103 and the second boundary line 104, the first boundary line 103 is close to the middle of the fiber fabric 100, and the second boundary line 104 coincides with the boundary line of the fiber fabric 100.

[0070] During the design and manufacturing process of wind turbine blades, the target edge 102 of the fiber fabric 100 is subjected to stress reduction treatment to reduce or avoid failure or damage of the wind turbine blade caused by stress concentration at the target edge 102 of the fiber fabric 100. The stress reduction treatment includes at least one operation of reducing thickness and cutting fiber continuity. Among them, reducing thickness is an operation of reducing the thickness of the target edge 102 of the fiber fabric 100 by physical methods. Since the fiber fabric 100 may have a sudden change in thickness at the target edge 102, this sudden change may cause stress concentration. Reducing thickness can be achieved by grinding, cutting or other mechanical methods, so that the thickness of the target edge 102 part is thinner than other parts of the fiber fabric 100, thereby reducing stress concentration.

[0071] As for cutting fiber continuity, the fiber fabric 100 as a whole has fiber continuity, and the stronger the fiber continuity, the more concentrated the stress. By cutting these continuous fibers, the influence of stress concentration can be eliminated or reduced. The method of cutting fiber continuity may be achieved by cutting part of the material, punching or laser processing.

[0072] Furthermore, the stress reduction treatment is applied to a specific area of ​​the fiber fabric 100, namely the target edge 102. The present application clarifies the target edge 102, and the target edge 102 is distinguished from other parts of the fiber fabric 100 by a first boundary line 103 and a second boundary line 104, that is, the area between the first boundary line 103 and the second boundary line 104 is the target edge 102. The first boundary line 103 is close to the middle of the fiber fabric 100, and the second boundary line 104 coincides with the boundary line of the fiber fabric 100. The width between the first boundary line 103 and the second boundary line 104 can be limited according to actual work requirements, so as to ensure strength while reducing stress as much as possible. The stress reduction treatment of the target edge 102 of the fiber fabric 100 can significantly improve the structural strength and durability of the wind turbine blade and reduce the risk of damage to the product caused by stress concentration.

[0073] like Figure 2 and Figure 3 As shown, in some embodiments of the present application, the target edge of the fiber fabric is subjected to a thickness reduction process, including: reducing the target edge from the inside to the outside of the target edge so that the thickness of the target edge shows a decreasing trend. In other words, the thickness reduction includes a bevel cutting process in which the thickness gradually decreases from the first boundary line 103 to the second boundary line 104 or a step cutting process in which the thickness gradually decreases from the first boundary line 103 to the second boundary line 104.

[0074] Among them, for the beveling process, the target edge 102 of the fiber fabric 100 starts from the first boundary line 103 and ends at the second boundary line 104, that is, from the target edge 102 of the fiber fabric 100 from the inside to the outside, its thickness gradually decreases to form an inclined slope. The slope can make the thickness change of the fiber fabric 100 at the target edge 102 smoother, reducing the stress concentration caused by the sudden change of thickness. Based on the different products used by the fiber fabric 100, the inclination angle A of the slope formed during the beveling process can be adjusted.

[0075] In addition, when the beveling process is performed on both sides of the fiber fabric 100, the widths of the target edges 102 on both sides may be the same or different, and at the same time, the inclination angles of the inclined surfaces formed by the beveling process may be the same or different.

[0076] Further, with respect to the step-cutting treatment, the step-cutting treatment is similar to the bevel-cutting treatment, but it adopts a step-like structure in the process of reducing the thickness. Specifically, starting from the first boundary line 103, the thickness of the fiber fabric 100 will experience a series of gradually decreasing steps, and finally reach the minimum thickness at the second boundary line 104. The step-cutting treatment method can also reduce stress concentration, and the number and size of the steps can be adjusted as needed to achieve more precise thickness control. In addition, the step-cutting treatment can also enhance the layering of the fabric target edge 102.

[0077] Among them, when stress relief treatment is performed on both sides of the fiber fabric 100, the widths of the target edges 102 on both sides can be the same or different, both sides can be treated with step cutting, and the number and size of the steps on both sides can be the same or different; of course, different treatment methods can also be used on the two sides, for example, one side uses a bevel cutting treatment and the other side uses a step cutting treatment.

[0078] Of course, in other embodiments of the present application, the thickness reduction may also be performed in other different ways, such as grinding.

[0079] like Figure 4 and Figure 5 As shown, in some embodiments of the present application, the target edge of the fiber fabric is treated to cut off the fiber continuity, including shearing the target edge into a serrated shape within the width range along the length direction of the target edge; or, breaking up the target edge; or, roughening the target edge.

[0080] Among them, as for the breaking up treatment, the breaking up treatment is a treatment method that disperses the fiber bundle by physical or chemical methods, thereby cutting off the continuity of the fibers. The breaking up treatment can break the connection between the single fibers in the fiber bundle or the fiber bundles, reduce the overall stiffness of the fiber fabric 100, and reduce stress concentration. The breaking up treatment can be achieved by a variety of methods, such as mechanical vibration, air flow impact, chemical dissolution, etc. The specific treatment method depends on the material and structure of the fiber fabric 100, as well as the required breaking up degree.

[0081] As for the roughening treatment, the roughening treatment is a method of forming tiny burrs or fiber clusters on the surface of the fiber fabric 100 to increase the surface roughness and friction, thereby cutting off the continuity of the fibers. The roughening treatment can be achieved by sandpaper polishing, chemical corrosion, electric spark machining, etc. A uniform layer of burrs will be formed on the surface of the treated fiber fabric 100, which can effectively cut off the continuity of the fibers and reduce stress concentration.

[0082] As for the tooth cutting process, the tooth cutting process is a method of cutting along a specific boundary line of the fiber fabric 100 (for example, the length direction of the first boundary line 103 or the second boundary line 104) so ​​that the fiber forms a tooth-shaped fracture at the cutting position. The tooth cutting process can cut off the continuity of the fiber along the extension direction of the first boundary line 103 while keeping the cut surface neat and stable.

[0083] The tooth cutting process is usually performed using a cutting tool with a serrated blade. For example, during the cutting process, the blade moves along the first boundary line 103, cuts the fiber and forms a serrated fracture, which can effectively reduce stress concentration. Figure 4 and Figure 5 As shown, the shape formed by the tooth cutting can be a sharp triangle, or a circular arc wave, and of course, it can also be other shapes.

[0084] Of course, the two sides of the fiber fabric 100 may be treated in the same manner or in different manners, for example, one side may be roughened and the other side may be sawtooth cut.

[0085] In a specific embodiment of the present invention, stress relief treatment is performed on the target edges 102 on both sides of the fiber fabric 100. Based on the above implementation of at least one of cutting fiber continuity and reducing thickness, the target edges 102 on both sides of the fiber fabric 100 can be treated in the same way or in different ways. Similarly, either side can only be treated by cutting fiber continuity or reducing thickness, or both treatments can be performed simultaneously.

[0086] For example, the fiber continuity and thickness reduction processes are simultaneously performed on the target edges 102 on both sides of the fiber fabric 100. Further, taking the sawtooth cutting process and the beveling process as an example, the sawtooth cutting process is performed after the beveling process is performed on the target edges 102 on both sides. Of course, the sawtooth cutting process can also be performed first and then the beveling process is performed, that is, the target edges 102 on both sides are thinned and the fiber continuity is cut, so that the stress concentration level is significantly reduced.

[0087] Figure 6 One of the flow charts of a method for forming a wind turbine blade provided in some embodiments of the present application is shown. Figure 7 One of the schematic diagrams of the skin mold structure provided by some embodiments of the present application is shown. Figure 8 A cross-sectional view of a staggered fiber fabric provided in some embodiments of the present application is shown.

[0088] like Figure 6 As shown, the present application also provides a method for forming a wind turbine blade, comprising the following steps: S101 to S103.

[0089] S101: performing stress relief treatment on a target edge of the fiber fabric, wherein the stress relief treatment includes thickness reduction treatment and / or fiber continuity cutting treatment;

[0090] Specifically, the fiber fabric can be woven from fiber yarns through a loom and cut into a specified width. For example, the width of the fiber fabric in a wind turbine blade can be 2540 mm, 1680 mm, 1270 mm, etc. The stress reduction treatment of the target edge of the fiber fabric in step S101 has been introduced in the above embodiment and will not be repeated here.

[0091] S102: laying the fiber fabric in the skin mold along the target direction, and retracting and displacing the fiber fabrics on the end sides in the axis direction of adjacent layers to form a staggered layer of fiber fabrics;

[0092] Specifically, the skin mold includes a blade root and a beam, and the fiber fabrics in different parts have different laying directions. For example, when laying the blade root, the fiber fabrics are laid from one side to the other side along the axis of the skin mold, and when laying the beam, the fiber fabrics are laid along the circumference of the skin mold and then laid from one side to the other side along the axis. In other words, the target direction is different for different laying parts, and the same part may need to be laid in multiple directions.

[0093] However, if Figure 7 and Figure 8As shown, no matter the laying of the blade root or the beam in the skin mold 300, the multi-layer fiber fabric 100 at least one end side of the fiber fabric staggered layer 200 finally formed is retracted and dislocated. The retracted and dislocated means that the target edge of the upper layer of fiber fabric 100 covers part of the target edge of the lower layer of fiber fabric 100; or when the upper layer of fiber fabric 100 is laid on the lower layer of fiber fabric 100, the target edge of the lower layer of fiber fabric 100 is completely exposed; in this way, the fiber fabric staggered layer 200 is formed by stacking up and down.

[0094] S103: laying the molding material on the fiber fabric staggered layer 200, injecting resin, and curing to form a skin;

[0095] Among them, the molding material can be foam plastics and other reinforcing materials. The molding material is laid in a certain order and layer to ensure the mechanical properties and structural strength of the wind turbine blade. After the molding material is laid, resin needs to be injected into the skin mold 300. The resin is combined with materials such as fiber fabrics to form a strong and durable composite material. The resin injection process needs to be strictly controlled to ensure the uniform distribution of the resin and sufficient infiltration of the fiber fabric. After the resin is injected, it needs to be cured. Curing is the process of converting the resin from liquid to solid, and it is also a key step in the molding of wind turbine blade skin products. During the curing process, parameters such as temperature and time need to be controlled to ensure that the resin can be fully cured to form a strong and durable wind turbine blade skin product. After the curing is completed, the wind turbine blade needs to be removed from the mold and necessary subsequent processing is carried out. This may include steps such as cutting, grinding, and painting to further improve the appearance and performance of the wind turbine blade.

[0096] S104: bonding the skin and other blade components to the blade body to form a wind turbine blade.

[0097] The blade body includes a beam and a blade root, and the skin is bonded to the beam and the blade root to form a complete wind turbine blade.

[0098] Fatigue cracking is a common problem in products such as wind turbine blades that work in high-load and high-stress environments. Since stress concentration is one of the main factors leading to fatigue cracking, reducing the stress concentration level at the ends of the fiber fabric in the skin can significantly improve the fatigue resistance of the product. This means that under the same working conditions, the wind turbine blade made of the fiber fabric treated with stress reduction in the above embodiment is less likely to have fatigue cracking at the end position, thereby extending the service life of the product.

[0099] At the same time, the staggered stacking of multiple layers of fiber fabrics further enhances the structural strength of the skin and effectively reduces the stress concentration level at the end, thereby improving the overall performance of the wind turbine blade.

[0100] Since the stress concentration level at the ends of the fiber fabric treated with stress relief is reduced, the material design safety factor can be appropriately reduced when designing wind turbine blades. This means that less material can be used to manufacture wind turbine blades while ensuring the performance and safety of wind turbine blades. The reduction in material usage not only reduces the cost of raw materials, but also reduces energy consumption and waste generation during processing and manufacturing, further reducing production costs. In addition, the lighter weight of the fiber fabric treated with stress relief can also reduce the overall weight of the wind turbine set and reduce infrastructure and transportation costs.

[0101] Fig. 9 A second flow chart of a method for forming a wind turbine blade provided in some embodiments of the present application is shown;

[0102] like Figure 7 and Fig. 9 As shown, in a specific embodiment of the present application, when preparing the fiber fabric staggered layers 200 of the blade root, steps S101 and S102 specifically include: steps S111 and S112.

[0103] S111: performing stress relief treatment on at least one side edge of the fiber fabric 100 in the width direction;

[0104] Specifically, the stress relief treatment may be performed on one edge in the width direction of the fiber fabric 100; or, the stress relief treatment may be performed on both edges in the width direction of the fiber fabric 100. That is, the target edge 102 may be one edge or both edges in the width direction.

[0105] S112: Lay the fiber fabric 100 in the skin mold 300 along the width direction parallel to the axis of the skin mold 300, retract and stagger the fiber fabric 100 on the end side of the axial direction of adjacent layers, and lay the fiber fabric 100 in a circumferential direction on the skin mold 300 in the length direction to form a fiber fabric staggered layer 200 at the blade root.

[0106] That is to say, the target edge 102 of the fiber fabric 100 is perpendicular to the axis of the skin mold 300, and multiple fiber fabrics 100 are laid in an overlapping manner along the axis until the width of the fiber fabric 100 of this layer reaches the required width of the blade root. In the skin mold 300 in the blade root area, the upper and lower layers of fiber fabrics 100 at the end are retracted and dislocated until the specified number of layers are laid. Among them, along the circumference of the skin mold 300, each fiber fabric 100 is laid around in the length direction. The shape of the skin mold 300 is consistent with the shape of the wind turbine blade.

[0107] In addition, the fiber fabric 100 after the stress relief treatment can be rolled into a roll for standby use and directly transported to a blade production factory for the next step, such as the production of skin products. The untreated fiber fabric can also be rolled into a roll for standby use, and then placed on a special device for unwinding, and then subjected to stress relief treatment during the unwinding process to obtain the fiber fabric after the stress relief treatment, which is then rolled up again for standby use.

[0108] Fig.10 A third flow chart of a method for forming a wind turbine blade provided in some embodiments of the present application is shown; Fig.11 A second schematic diagram of the structure of a skin mold 300 provided in some embodiments of the present application is shown.

[0109] like Fig.10 As shown, in a specific embodiment of the present application, when preparing the fiber fabric staggered layers 200 of the beam, steps S101 and S102 specifically include: steps S113 and S114.

[0110] S113: performing stress relief treatment on at least one side edge of the fiber fabric 100 in the length direction;

[0111] When laying the fiber fabric at the beam position in the skin mold 300, the fiber fabric 100 of corresponding length needs to be cut according to the length in the axis direction of the skin mold 300, and the target edge for stress relief treatment is at least one of the opposite edges in the length direction of the fiber fabric 100.

[0112] S114: Lay the fiber fabric 100 in the skin mold 300 along a direction parallel to the axis of the skin mold 300, and retract and dislocate the fiber fabric 100 at the end sides of the axis direction of adjacent layers to form a fiber fabric staggered layer 200 of the beam.

[0113] like Fig.11 As shown, each long strip of fiber fabric 100 is laid along the length direction of the skin mold 300; along the circumference of the skin mold 300, multiple fiber fabrics 100 are overlapped and laid, so that the fiber fabric 100 covers the beam part of the skin mold 300. In the length direction, that is, the axial direction of the skin mold 300, the two ends of the upper fiber fabric 100 and the two ends of the lower fiber fabric 100 are retracted and staggered.

[0114] The fiber fabric staggered layers 200 of the beam and the fiber fabric 100 of the blade root may be laid simultaneously or successively, and the fiber fabric staggered layers 200 of the beam and the fiber fabric staggered layers 200 of the blade root may overlap each other.

[0115] Furthermore, in a specific embodiment of the present application, in order to reduce the stress level of the wind turbine blade and ensure the strength of the skin product, the width of the target edge 102 of the fiber fabric 100 ranges from 0.5 mm to 50 mm.

[0116] Fig.12 A fourth flow chart of a method for forming a wind turbine blade provided in some embodiments of the present application is shown. Fig.13 A schematic structural diagram of a fabric block provided in some embodiments of the present application is shown.

[0117] like Fig.12 As shown, in order to improve the production efficiency of the skin, in another embodiment of the present application, with respect to step S102, the fiber fabric is laid in the skin mold 300 along the target direction, and the fiber fabrics on the end sides in the axial direction of adjacent layers are retracted and staggered to form a fiber fabric staggered layer 200, including: steps S201 to S204.

[0118] S201: cutting the fiber fabric after the stress relief treatment into a specified size to obtain a fabric block 110;

[0119] Specifically, Fig.10 As shown, according to the design size requirements of the wind turbine blade, the rolled fiber fabric is cut into fabric blocks 110 of a specified length and packaged for standby use. Compared with determining the size when laying the skin mold 300, the fabric blocks 110 determined in advance to a specified length are more efficient, facilitate the production of blade root skin products, and improve the efficiency of laying the fiber fabric on the skin mold 300.

[0120] S202: overlapping the fabric blocks 110 along the axial direction to form a fabric block layer;

[0121] like Figure 8 As shown, after the fabric block 110 is laid in the skin mold 300, the two edges of the fabric block 110 along the axis of the skin mold 300 can both be target edges, that is, both have undergone stress reduction treatment, and when adjacent fabric blocks 110 are overlapped, they can be overlapped at the target edge position to form a fabric block layer. Of course, adjacent fabric blocks 110 can also be overlapped in the body area.

[0122] S203: stacking and connecting multiple fabric blocks, and retracting and dislocating two ends of the fabric blocks of two adjacent layers in the axial direction to form a stitching block 201;

[0123] That is to say, when the fabric blocks are stacked, the two ends of the fabric blocks are retracted and dislocated, and after being stacked and connected to a specified number of layers, a stitching block 201 is formed.

[0124] S204 : Laying the sewing block 201 in the skin mold 300 along the target direction to form the fiber fabric staggered layer 200 .

[0125] For example, in the fiber fabric staggered layer 200 at the blade root position of the skin mold 300, multiple stitching blocks 201 can be further overlapped to form a combined layer, and then multiple combined layers are stacked in a retracted and staggered manner to improve the laying efficiency.

[0126] The present application also provides a wind turbine blade, comprising: a skin and a blade body, the skin comprising a fiber fabric staggered layer 200, wherein the fiber fabric staggered layer 200 comprises a plurality of fiber fabric sheets, the end sides of adjacent fiber fabric sheets are retracted and staggered, the fiber fabric sheets comprise overlapping fiber fabrics, the fiber fabrics have stress-reducing edges, the stress of the stress-reducing edges is less than the stress of the fiber fabric edges in the initial state, wherein the fiber fabrics in the initial state are conventional fiber fabrics that do not implement stress-reducing measures. The skin is bonded to the surface of the blade body.

[0127] The wind turbine blade in the present application can be realized by the forming method of the wind turbine blade in the above embodiment. The fiber fabric in the wind turbine blade in the present application can be the fiber fabric that has been subjected to stress reduction treatment in the above embodiment, and the stress reduction edge of the fiber fabric in the wind turbine blade is the target edge of the fiber fabric that has been subjected to stress reduction treatment in the above embodiment.

[0128] For example, the fiber fabric staggered layer 200 has a stress-reducing edge along the width direction, i.e., the target edge 102, the thickness of the target edge 102 along the width direction is less than the thickness of the main area 101, and / or the fiber continuity of the target edge 102 along the width direction is lower than the fiber continuity of the main area 101; the width direction of the fiber fabric staggered layer 200 in the blade root area is perpendicular to the axis of the blade body.

[0129] The fiber fabric staggered layer 200 has a target edge 102 along the length direction, the thickness of the target edge 102 along the length direction is less than the thickness of the main area 101, and / or the fiber continuity of the target edge 102 along the length direction is lower than the fiber continuity of the main area 101; the length direction of the fiber fabric 100 in the beam area of ​​the fiber fabric staggered layer 200 is parallel to the axis of the blade body.

[0130] In other embodiments of the present application, the width of the stress-relief edge ranges from 0.5 mm to 50 mm.

[0131] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A method for forming a wind turbine blade, characterized in that: include: Performing stress relief treatment on the target edge of the fiber fabric, wherein the stress relief treatment includes thickness reduction treatment and / or fiber continuity cutting treatment; Laying the fiber fabric in the skin mold along the target direction, and retracting and displacing the fiber fabric at the end sides in the axis direction of adjacent layers to form a staggered layer of fiber fabric; Laying the molding material on the staggered layers of the fiber fabric, injecting resin, and curing to form a skin; The skin and other blade components are bonded to the blade body to form a wind turbine blade.

2. The method for forming a wind turbine blade according to claim 1, characterized in that: The method of reducing the thickness of the target edge of the fiber fabric comprises: The target edge is cut along the direction from the inside to the outside of the target edge, so that the thickness of the target edge shows a decreasing trend.

3. The method for forming a wind turbine blade according to claim 1 or 2, characterized in that: The method of cutting off the fiber continuity of the target edge of the fiber fabric comprises: Along the length direction of the target edge, shearing the target edge within the width range into a serrated shape; Alternatively, the target edge is broken up; Alternatively, the target edge is roughened.

4. The method for forming a wind turbine blade according to claim 1, characterized in that: When preparing the staggered layers of fiber fabrics for blade roots, the target edges of the fiber fabrics are subjected to stress relief treatment; The fiber fabric is laid in a skin mold along a target direction, and the fiber fabrics at the end sides in the axis direction of adjacent layers are retracted and dislocated to form a fiber fabric staggered layer, including: Performing stress relief treatment on at least one edge of the fiber fabric in the width direction; The fiber fabric is laid in the skin mold along a width direction parallel to the axis of the skin mold, the fiber fabrics on the end sides in the axis direction of adjacent layers are retracted and staggered, and the fiber fabrics are laid circumferentially on the skin mold in the length direction to form staggered fiber fabric layers at the blade root.

5. The method for forming a wind turbine blade according to claim 1, characterized in that: When preparing the fiber fabric staggered of the beam, the target edge of the fiber fabric is subjected to stress relief treatment; The fiber fabric is laid in a skin mold along a target direction, and the fiber fabrics at the end sides in the axis direction of adjacent layers are retracted and dislocated to form a fiber fabric staggered layer, including: Performing stress relief treatment on at least one side edge of the fiber fabric in the length direction; The fiber fabric is laid in the skin mold along a direction parallel to the axis of the skin mold, and the fiber fabrics on the end sides of the axis direction of adjacent layers are retracted and staggered to form staggered fiber fabrics of the beam.

6. The method for forming a wind turbine blade according to claim 1, 4 or 5, characterized in that: The fiber fabric is laid in the skin mold along the target direction, and the fiber fabrics at the end sides in the axis direction of adjacent layers are retracted and displaced to form a fiber fabric staggered layer, including: Cutting the fiber fabric after the stress relief treatment into specified sizes to obtain a fabric block; Overlapping the fabric blocks along the axial direction to form a fabric block layer; The plurality of fabric blocks are stacked and connected, and the two ends of the two adjacent fabric blocks in the axial direction are retracted and staggered to form a stitched block; The stitching blocks are laid in a skin mould along a target direction to form staggered layers of fibre fabric.

7. A wind turbine blade, characterized in that: include: The skin comprises a fiber fabric staggered layer, wherein the fiber fabric staggered layer comprises a plurality of fiber fabric sheets, the end sides of adjacent fiber fabric sheets are retracted and staggered to be connected, the fiber fabric sheets comprise overlapping fiber fabrics, the fiber fabrics have stress-reducing edges, and the stress of the stress-reducing edges is less than the stress of the fiber fabric edges in an initial state; The blade body, the skin is bonded to the surface of the blade body.

8. The wind turbine blade according to claim 7, characterized in that: The thickness of the stress-reducing edge gradually decreases from the inside to the outside.

9. The wind turbine blade according to claim 7, characterized in that: The stress-relief edge comprises a tooth structure.

10. The wind turbine blade according to any one of claims 7 to 9, characterized in that: The width of the stress-relief edge ranges from 0.5 mm to 50 mm.

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