Forming method for wind turbine blade, and wind turbine blade

Abstract

The present application discloses a forming method for a wind turbine blade, and a wind turbine blade. The forming method for a wind turbine blade comprises: performing stress reduction treatment on a target edge of a fiber fabric, wherein the stress reduction treatment comprises thickness reduction treatment and / or fiber continuity cutting treatment; laying the fiber fabric in a skin mold in a target direction to form a staggered-configuration fiber fabric layer; injecting resin and performing curing to form a skin; and bonding the skin and other blade components to a blade body to form a wind turbine blade. The present application solves the problem in the prior art of larger stress concentration of a wind turbine blade.

Description

Method for forming wind turbine blade and wind turbine blade

[0001] Cross-reference to Related Applications

[0002] This application claims priority to Chinese Patent Application No. 202410809324.3, filed on June 21, 2024, entitled “Method for forming wind turbine blade and wind turbine blade”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application belongs to the field of wind turbine blades, and in particular relates to a method for forming a wind turbine blade and a wind turbine blade. BACKGROUND

[0004] Wind turbine blades are the core components of wind turbine generators, and their main function is to convert the wind energy in nature into electrical energy of wind turbine generators. 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 turbine generators.

[0005] The shape and size of wind turbine blades directly affect the rotational speed and output power of wind turbine generators. Common wind turbine blade shapes include straight wing type, curved wing type and twisted wing type. Among them, straight wing type blades have lower manufacturing and maintenance costs, but their performance is poor at high wind speeds, prone to fatigue cracks, and relatively loud noise. Curved wing type blades and twisted wing type blades can provide higher wind energy conversion efficiency at different wind speeds, but have relatively high manufacturing and maintenance costs.

[0006] As wind turbine generators continue to grow in size, the corresponding wind turbine blades also continue to grow in size, and the wind turbine blades are more affected by stress concentration, reducing fatigue resistance. SUMMARY

[0007] 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 the fatigue resistance of the wind turbine blade.

[0008] In a first aspect, the present application provides a method for forming a wind turbine blade, comprising:

[0009] performing stress reduction treatment on a target edge of the fiber fabric, wherein the stress reduction treatment includes thickness reduction treatment and / or fiber continuity cutting treatment;

[0010] laying the fiber fabric in the skin mold along a target direction, and performing back-off misplacement of the fiber fabric on the end side of the adjacent layer axis direction to form fiber fabric mislayers;

[0011] Laying up a forming material on the fibre fabric plies and injecting resin, curing to form a skin;

[0012] Bonding the skin and other blade components to a blade body to form a wind turbine blade.

[0013] The method for forming a wind turbine blade according to the embodiments of the present application, the target edge of the fibre fabric is subjected to a thickness reduction treatment, comprising:

[0014] The target edge is reduced in thickness along a direction from inside to outside of the target edge.

[0015] The method for forming a wind turbine blade according to the embodiments of the present application, the target edge of the fibre fabric is subjected to a fibre continuity treatment, comprising:

[0016] The target edge is cut into a zigzag shape along a length direction of the target edge;

[0017] Or, the target edge is subjected to a scattering treatment;

[0018] Or, the target edge is subjected to a roughening treatment.

[0019] The method for forming a wind turbine blade according to the embodiments of the present application, when preparing fibre fabric plies of a root, the target edge of the fibre fabric is subjected to a stress reduction treatment; the fibre fabric is laid up in a skin mould along a target direction, the fibre fabric at an end side of an axis direction of adjacent layers is subjected to a back-drawing staggered arrangement, to form fibre fabric plies, comprising:

[0020] At least one side edge of the fibre fabric in a width direction is subjected to a stress reduction treatment;

[0021] The fibre fabric is laid up in the skin mould along a direction parallel to an axis direction of the skin mould in a width direction, the fibre fabric at an end side of an axis direction of adjacent layers is subjected to a back-drawing staggered arrangement, the fibre fabric is laid up on the skin mould in a length direction in a circumferential direction, to form fibre fabric plies of a blade.

[0022] The method for forming a wind turbine blade according to the embodiments of the present application, when preparing fibre fabric plies of a beam, the target edge of the fibre fabric is subjected to a stress reduction treatment; the fibre fabric is laid up in a skin mould along a target direction, the fibre fabric at an end side of an axis direction of adjacent layers is subjected to a back-drawing staggered arrangement, to form fibre fabric plies, comprising:

[0023] At least one side edge of the fibre fabric in a length direction is subjected to a stress reduction treatment;

[0024] The length of the fiber fabric is laid in the skin mold along the direction parallel to the axis of the skin mold, and the fiber fabric at the end side of the adjacent layers in the axis direction is retracted and staggered to form the fiber fabric staggered layers of the beam.

[0025] According to the forming method of the wind power blade provided in the embodiments of the present application, the fiber fabric is laid in the skin mold along the target direction, the fiber fabric at the end side of the adjacent layers in the axis direction is retracted and staggered to form the fiber fabric staggered layers, which comprises the following steps:

[0026] The fiber fabric after the stress reduction treatment is cut into a specified size to obtain a fabric block.

[0027] The plurality of layers of the fabric blocks are stacked and connected, and the two ends of the fabric blocks in the axis direction of the connected two layers are retracted and staggered to form a stitched block.

[0028] The stitched block is laid in the skin mold along the target direction to form the fiber fabric staggered layers.

[0029] In a second aspect, the present application further provides a wind power blade, comprising:

[0030] A skin comprises fiber fabric staggered layers, wherein the fiber fabric staggered layers comprise a plurality of layers of fiber fabric pieces, the end sides of adjacent fiber fabric pieces are retracted and staggered to be connected, the fiber fabric pieces comprise overlapped fiber fabric, the fiber fabric has a stress-reduced edge, and the stress of the stress-reduced edge is less than that of the edge of the fiber fabric in the initial state.

[0031] A blade body, and the skin is bonded to the surface of the blade body.

[0032] According to the wind power blade provided in the embodiments of the present application, the thickness of the stress-reduced edge gradually decreases from inside to outside.

[0033] According to the wind power blade provided in the embodiments of the present application, the stress-reduced edge comprises a tooth structure.

[0034] According to the wind power blade provided in the embodiments of the present application, the width of the stress-reduced edge ranges from 0.5 mm to 50 mm.

[0035] The forming method of the wind power blade and the wind power blade provided in the embodiments of the present application can reduce the stress concentration effect caused by the sudden end of the fiber bundle by at least one operation of reducing the thickness of the edge of the fiber fabric and cutting the fiber continuity, so that the stress concentration level of the edge of the fiber fabric is significantly reduced, thereby reducing the local stress concentration of the wind power blade, significantly improving the fatigue resistance of the wind power blade, reducing the failure of the wind power blade, and prolonging the service life of the wind power blade, thereby reducing the cost. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly introduced as follows, and other drawings can be obtained by those of ordinary skill in the art without any creative effort on the basis of these drawings.

[0037] Fig. 1 shows a structural schematic diagram of a fiber fabric after stress reduction treatment according to some embodiments of the present application;

[0038] Fig. 2 shows a cross-sectional view of a fiber fabric obtained by using a cutting bevel angle according to some embodiments of the present application;

[0039] Fig. 3 shows a cross-sectional view of a fiber fabric obtained by using a cutting step according to some embodiments of the present application;

[0040] Fig. 4 shows a structural schematic diagram of a fiber fabric with a target edge in the form of teeth according to some embodiments of the present application;

[0041] Fig. 5 shows another structural schematic diagram of a fiber fabric with a target edge in the form of teeth according to some embodiments of the present application;

[0042] Fig. 6 shows a flowchart of a forming method of a wind turbine blade according to some embodiments of the present application;

[0043] Fig. 7 shows a structural schematic diagram of a skin mold according to some embodiments of the present application;

[0044] Fig. 8 shows a cross-sectional view of a fiber fabric stagger according to some embodiments of the present application;

[0045] Fig. 9 shows another flowchart of a forming method of a wind turbine blade according to some embodiments of the present application;

[0046] Fig. 10 shows a third flowchart of a forming method of a wind turbine blade according to some embodiments of the present application;

[0047] Fig. 11 shows another structural schematic diagram of a skin mold according to some embodiments of the present application;

[0048] Fig. 12 shows a fourth flowchart of a forming method of a wind turbine blade according to some embodiments of the present application;

[0049] Fig. 13 shows a structural schematic diagram of a fabric block according to some embodiments of the present application.

[0050] Reference signs: 100, fiber fabric; 101, main body area; 102, target edge; 103, first boundary line; 104, second boundary line; 110, fabric block; 200, fiber fabric stagger; 201, stitching block; 300, skin mold. DETAILED DESCRIPTION

[0051] The features and exemplary embodiments of the various aspects of the present application will be described in detail below with reference to the drawings. The following detailed description is merely intended to teach a person skilled in the art how to make and use the best mode of the present application and is not intended to limit the scope of the application. Therefore, specific structural and functional details disclosed herein are not to be interpreted in a manner that

[0052] It should be noted that the terms such as first and second, etc., are merely intended 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 such entities or operations. Moreover, the terms "include", "contain" 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 not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, 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.

[0053] The structure of a wind turbine blade will be briefly introduced below to better understand the present application. The structure of a wind turbine blade can be subdivided into several key components, each with its unique function and composition. The following is a detailed explanation of these components:

[0054] Skin: The skin is the main external structure of a 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 stiffness of the blade, while the core material is used to fill and enhance the overall performance of the structure. The resin is used to bond the glass fiber fabric and the core material together to form a strong composite structure. The skin covers the outside of the spar system and the root system.

[0055] Beam System: The main role of the beam system is to effectively transfer the wind energy loads 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, and 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, and the skin of the trailing edge beam is also composed of fiber fabric and resin, mainly used to support the trailing edge structure and transfer loads. The web is located between the main beam and the trailing edge beam, and the skin outside the web is usually composed of glass fiber resin. The web also includes a core material that connects the main beam and the trailing edge beam and enhances the overall stiffness of the blade.

[0056] Blade Root System: The blade root system is the connection between the wind turbine blade and the hub, used to smoothly transfer the wind energy captured by the blade to the hub and support the weight of the entire blade. The skin outside the blade root system is generally composed of glass fiber and resin, and the blade root system also includes a blade root metal connector. Glass fiber and resin provide the strength and stiffness of the structure, while the metal connector is used to firmly connect the blade and the hub together.

[0057] The above components together constitute the overall structure of the wind turbine blade, and each part plays a crucial role. With the continuous development of wind power technology, the structure of the wind turbine blade is also constantly optimized and innovated to improve wind energy conversion efficiency, reduce blade weight and cost, and enhance the durability and safety of the blade.

[0058] With the increasing demand for electricity from wind power, wind turbine generators are expanding, and the size of wind turbine blades is continuously growing to accommodate larger wind energy capture and higher energy conversion efficiency. However, this increase in size also brings an increase in blade weight and cost, as well as challenges in design and manufacturing. In the design of wind turbine blades, especially in critical areas such as the blade root system, how to balance strength, weight, cost, and manufacturing efficiency has become a problem that needs to be solved.

[0059] First of all, the blade root system is the main area of the blade to withstand bending loads, and its design is crucial to the overall performance of the blade. In order to withstand these loads, engineers usually choose to use thicker axial glass fiber fabric as the skin of the blade root system. However, too thick a fiber fabric not only increases the weight of the blade, but also may cause stress concentration problems, thereby reducing the durability and safety of the blade.

[0060] To solve this problem, engineers have adopted various strategies. One common approach is to use axial staggered transitions in the glass fiber fabric to reduce stress concentration caused by thickness discontinuity. This strategy can alleviate the problem of stress concentration to some extent, but it cannot completely eliminate it.

[0061] In addition, with the development of technology, the thickness of single-layer glass fiber fabric is gradually reduced, although the stress concentration of thinner fiber fabric at the end position of each layer of fiber fabric is weaker, but it also increases the number of laying layers, thereby affecting the production efficiency. In order to solve this contradiction, some innovative methods are put forward, such as the multi-layer fiber fabric can be sewn together first, and then laid, so as to ensure the strength while improving the production efficiency.

[0062] However, with the large use of ultra-high modulus glass fabric in wind power blades, even if thin fiber fabric is used, the end stress concentration level may be difficult to meet the design and use requirements of wind power blades. This is because the ultra-high modulus glass fabric has higher strength and stiffness, but the end stress is also increased accordingly, and in the process of applying the ultra-high modulus glass fabric to the wind power blade, the end step is more likely to cause stress concentration at the end of the protrusion and damage.

[0063] Based on the above problems in the prior art, the present application mainly deals with the stress concentration problem caused by the fiber fabric in the skin system. For a certain width of fiber fabric, the edge in the width direction or the edge in the length direction is processed in a certain range to reduce the stress concentration of the fiber fabric end, reduce the stress concentration level of the fiber fabric end, improve the fatigue resistance of the skin system, and further improve the overall fatigue resistance of the wind power blade and reduce cracking.

[0064] In order to solve the problems in the prior art, the embodiments of the present application provide a forming method of a wind power blade and a wind power blade. First, the fiber fabric provided by the embodiments of the present application is introduced.

[0065] Figure 1 shows a structural schematic diagram of the fiber fabric after stress reduction processing provided by some embodiments of the present application.

[0066] As shown in Figure 1, one embodiment of the present application provides a fiber fabric 100, which includes a main body area 101 and a target edge 102, the target edge 102 is adjacent to the side of the main body area 101, and the thickness of the target edge 102 is less than the thickness of the main body area 101 and / or the fiber continuity of the target edge 102 is lower than the fiber continuity of the main body area 101. For the target edge 102 of the fiber fabric 100, the independent block of the fiber fabric 100 includes two opposite side edges in the length direction and two opposite side edges in the width direction, and the target edge 102 in the present application is any one or more of the above edges.

[0067] Specifically, the main body region 101 of the fiber fabric 100 is the main component and occupies 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 thickness of the target edge 102 is smaller or the fiber continuity of the target edge 102 is lower, and 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, improving the fatigue resistance and durability of the fiber fabric 100.

[0068] Specifically, due to the alleviation of the stress concentration phenomenon of the target edge 102, 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 the amount of material, and thus reduce the production cost.

[0069] FIG. 2 shows a cross-sectional view of a fiber fabric obtained by using a cutting angle according to some embodiments of the present application; FIG. 3 shows a cross-sectional view of a fiber fabric obtained by using a cutting step according to some embodiments of the present application; FIG. 4 shows a schematic view of a structure of a target edge of a fiber fabric according to some embodiments of the present application; and FIG. 5 shows another schematic view of a structure of a target edge of a fiber fabric according to some embodiments of the present application.

[0070] As shown in FIGS. 2 to 5, the present application provides a fiber fabric processing method, and the fiber fabric mentioned in the above embodiments can be obtained by using the following method, which specifically comprises: performing stress reduction processing on the target edge 102 of the fiber fabric 100, the stress reduction processing including at least one operation of reducing thickness and cutting fiber continuity; wherein the target edge 102 includes a first boundary line 103 and a second boundary line 104, the stress reduction processing 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.

[0071] In the design and manufacturing process of the wind turbine blade, the target edge 102 of the fiber fabric 100 is subjected to stress reduction treatment to reduce or avoid the failure or damage of the wind turbine blade due to stress concentration of the target edge 102 of the fiber fabric 100. The stress reduction treatment includes at least one of thickness reduction and fiber continuity cutting. Among them, the thickness reduction is an operation of reducing the thickness of the target edge 102 of the fiber fabric 100 by a physical method. Since the fiber fabric 100 may have a thickness mutation at the target edge 102, such mutation may cause stress concentration. The thickness reduction can be achieved by grinding, cutting or other mechanical methods, so that the thickness of the target edge 102 part is lighter than other parts of the fiber fabric 100, thereby reducing stress concentration.

[0072] For fiber continuity cutting, the fiber fabric 100 has fiber continuity as a whole, and the stronger the fiber continuity, the more concentrated the stress. By cutting these continuous fibers, the effect of stress concentration can be eliminated or reduced. The method of cutting fiber continuity can be achieved by techniques such as shearing part of the material, punching or laser treatment.

[0073] Further, the stress reduction treatment is applied to a specific area of the fiber fabric 100, i.e. the target edge 102. The target edge 102 is defined in this application, and the target edge 102 is distinguished from other parts of the fiber fabric 100 by the first boundary line 103 and the second boundary line 104, i.e. 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 to ensure strength while minimizing stress. The target edge 102 of the fiber fabric 100 is subjected to stress reduction treatment, which can significantly improve the structural strength and durability of the wind turbine blade and reduce the risk of damage to the product due to stress concentration.

[0074] As shown in FIGS. 2 and 3, in some embodiments of the present application, the target edge of the fiber fabric is subjected to thickness reduction treatment, including: reducing the target edge in the direction from inside to outside along the target edge, so that the thickness of the target edge decreases in a decreasing trend. In other words, the thickness reduction includes a cutting angle treatment with gradually decreasing thickness from the first boundary line 103 to the second boundary line 104 or a cutting step treatment with gradually decreasing thickness from the first boundary line 103 to the second boundary line 104.

[0075] For the cutting bevel processing, 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 inside to the outside of the target edge 102 of the fiber fabric 100, the thickness gradually decreases to form an inclined bevel. The bevel can make the thickness of the fiber fabric 100 at the target edge 102 more smooth, reducing stress concentration caused by sudden thickness changes. Based on the different products to which the fiber fabric 100 is applied, the inclination angle A of the bevel formed in the cutting bevel processing can be adjusted.

[0076] In addition, when both sides of the fiber fabric 100 are subjected to cutting bevel processing, the target edges 102 of the two sides can have the same or different widths, and the inclination angles of the bevels formed can also be the same or different.

[0077] Further, for the cutting step processing, the cutting step processing is similar to the cutting bevel processing, but it adopts a stepped structure in the process of reducing the thickness. Specifically, starting from the first boundary line 103, the thickness of the fiber fabric 100 will go through a series of steps of gradually decreasing, and finally reach the minimum thickness at the second boundary line 104. The cutting step processing 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 cutting step processing can also enhance the level of the target edge 102 of the fabric.

[0078] In addition, when both sides of the fiber fabric 100 are subjected to cutting bevel processing, the target edges 102 of the two sides can have the same or different widths, and the inclination angles of the bevels formed can also be the same or different.

[0079] Of course, in other embodiments of the present application, the thickness reduction can also have other different processing methods, such as grinding, etc.

[0080] As shown in FIGS. 4 and 5, in some embodiments of the present application, the target edge of the fiber fabric is subjected to cutting fiber continuity processing, which includes cutting the width range of the target edge into a zigzag shape along the length direction of the target edge; or doing scattering processing on the target edge; or doing roughening processing on the target edge.

[0081] In terms of the dispersing treatment, the dispersing treatment is a treatment method that disperses the fiber bundle by physical or chemical methods to cut off the continuity of the fibers. The dispersing treatment can break the connection between the individual fibers in the fiber bundle or between the fiber bundles, reduce the overall stiffness of the fiber fabric 100, and reduce stress concentration. The dispersing treatment can be achieved by various 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 desired degree of dispersing.

[0082] In terms of the roughening treatment, the roughening treatment is a method of forming small 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 sanding, chemical etching, electrical discharge machining, etc. The surface of the treated fiber fabric 100 will form a layer of uniform burrs, which can effectively cut off the continuity of the fibers and reduce stress concentration.

[0083] In terms of the tooth cutting treatment, the tooth cutting treatment is a way of cutting along a specific boundary line (e.g. the length direction of the first boundary line 103 or the second boundary line 104) of the fiber fabric 100, so that the fibers form a tooth-shaped fracture at the cutting point. The tooth cutting treatment can cut off the continuity of the fibers along the extension direction of the first boundary line 103 while maintaining the neatness and stability of the cutting surface.

[0084] The tooth cutting treatment 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, cutting off the fibers and forming a serrated fracture, which can effectively reduce stress concentration. As shown in FIGS. 4 and 5, the tooth cutting shape can be a sharp triangle, a circular arc wave, or other shapes.

[0085] Of course, the same treatment method can be used on both sides of the fiber fabric 100, or different treatment methods can be used, for example, one side uses roughening treatment and the other side uses serrated cutting treatment.

[0086] In specific embodiments of the present application, the opposite target edges 102 of the fiber fabric 100 are subjected to stress reduction treatment. Based on the above at least one way of cutting off the continuity of the fibers and reducing the thickness, the target edges 102 of the fiber fabric 100 on both sides can be treated in the same way or in different ways. Similarly, either side can only be subjected to the continuity cutting treatment or the thickness reduction treatment, or both treatments can be performed simultaneously.

[0087] For example, the fiber continuity is cut and the thickness is reduced at the same time at the two target edges 102 of the fiber fabric 100, and further, the cutting at an angle and the cutting with a sawtooth are taken as examples, the cutting at an angle is performed at the two target edges 102, and then the cutting with a sawtooth is performed. Of course, the cutting with a sawtooth can be performed first, and then the cutting at an angle is performed, that is, the two target edges 102 are thinned and the fiber continuity is cut at the same time, so that the stress concentration level is obviously reduced.

[0088] FIG. 6 shows one of the flowcharts of the method for forming a wind turbine blade according to some embodiments of the present application, FIG. 7 shows one of the schematic diagrams of the skin mold structure according to some embodiments of the present application, and FIG. 8 shows a sectional view of the fiber fabric staggered layer according to some embodiments of the present application.

[0089] As shown in FIG. 6, the present application further provides a method for forming a wind turbine blade, including the following steps: S101-S103.

[0090] S101: performing stress reduction treatment on the target edge of the fiber fabric, wherein the stress reduction treatment includes thickness reduction treatment and / or fiber continuity cutting treatment;

[0091] Specifically, the fiber fabric can be prepared by a loom and cut into a specified width. For example, the width of the fiber fabric in the wind turbine blade can be 2540mm, 1680mm, 1270mm, etc. The stress reduction treatment on the target edge of the fiber fabric in step S101 has been described in the above embodiments, and will not be repeated here.

[0092] S102: laying the fiber fabric in the target direction in the skin mold, and performing staggered layering of the fiber fabric at the end side of the adjacent layer axis direction by backfolding, to form a fiber fabric staggered layer;

[0093] Specifically, the skin mold includes a root part and a beam part, and the laying direction of the fiber fabric at different parts is different. For example, when laying the root part, the fiber fabric is laid from one side to the other side along the axis direction of the skin mold, and when laying the beam part, the fiber fabric is laid along the circumferential direction of the skin mold, and then laid from one side to the other side along the axis direction. That is, the target direction is different for different laying parts, and the same part can need to be laid in multiple directions.

[0094] However, as shown in FIGS. 7 and 8, regardless of the laying of the blade root part or the beam part in the skin mold 300, the multi-layer fiber fabric 100 at least one end side of the finally formed fiber fabric layer 200 is retracted and staggered. Among them, the retracted staggered position is that the target edge of the upper layer of the fiber fabric 100 covers part of the target edge of the lower layer of the fiber fabric 100; or when the upper layer of the fiber fabric 100 is laid on the lower layer of the fiber fabric 100, the target edge of the lower layer of the fiber fabric 100 is completely exposed; and the upper and lower layers are stacked to form the fiber fabric layer 200.

[0095] S103: Lay the forming material on the fiber fabric layer 200, inject resin, and cure to form the skin;

[0096] Among them, the forming material can be foam plastic and other reinforcing materials, etc. The forming material is laid in a certain order and level to ensure the mechanical properties and structural strength of the wind turbine blade. After the forming material is laid, resin needs to be injected into the skin mold 300. The resin combines with materials such as fiber fabric to form a strong and durable composite material. The resin injection process needs to be strictly controlled to ensure uniform distribution and full infiltration of the resin into the fiber fabric. After the resin is injected, curing treatment is needed. Curing is the process of changing resin from liquid to solid, and is also a key step in the forming of the wind turbine blade skin product. 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 curing, the wind turbine blade needs to be taken out of the mold and subjected to necessary subsequent processing. This may include cutting, polishing, painting, etc. to further improve the appearance and performance of the wind turbine blade.

[0097] S104: Bond the skin and other blade components to the blade body to form a wind turbine blade.

[0098] Among them, the blade body includes a beam and a blade root. The skin is bonded to the beam and the blade root to form a complete wind turbine blade.

[0099] In products such as wind turbine blades that work in high-load and high-stress environments, fatigue cracking is a common problem. Since stress concentration is one of the main factors leading to fatigue cracking, reducing the stress concentration level of the fiber fabric end of 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 subjected to the stress reduction treatment in the above embodiment is less likely to have fatigue cracking at the end position, thereby prolonging the service life of the product.

[0100] At the same time, the staggered stacking of the multi-layer fiber fabric further enhances the structural strength of the skin and effectively reduces the end stress concentration level, improving the overall performance of the wind turbine blade.

[0101] Due to the reduced stress concentration level of the fiber fabric end head after stress reduction treatment, the material design safety factor of the wind turbine blade can be appropriately reduced during design. This means that less material can be used to manufacture the wind turbine blade while ensuring the performance and safety of the wind turbine blade. The reduction of 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 stress-reduced fiber fabric is lighter in weight, which can also reduce the overall weight of the wind turbine generator, reducing infrastructure and transportation costs.

[0102] Fig. 9 shows a flowchart of a method for forming a wind turbine blade according to some embodiments of the present application;

[0103] As shown in Figs. 7 and 9, in one specific embodiment of the present application, when preparing the fiber fabric interlayer 200 of the root, steps S101 and S102 specifically include steps S111 and S112.

[0104] S111: Stress reduction treatment is performed on at least one side edge of the fiber fabric 100 in the width direction;

[0105] Specifically, stress reduction treatment can be performed on one side edge of the fiber fabric 100 in the width direction, or stress reduction treatment can be performed on both side edges of the fiber fabric 100 in the width direction. That is, the target edge 102 can be one or both side edges in the width direction.

[0106] S112: The fiber fabric 100 is laid in the skin mold 300 along the direction parallel to the axis of the skin mold 300, the fiber fabric 100 at the end side of the adjacent layer axis direction is back-drawn and misaligned, the fiber fabric 100 is laid in the length direction around the skin mold 300, and the fiber fabric interlayer 200 of the root is formed.

[0107] That is, the target edge 102 of the fiber fabric 100 is perpendicular to the axis of the skin mold 300, and a plurality of fiber fabrics 100 are laid in the axial direction until the width of the fiber fabric 100 of the layer reaches the required width of the root. In the skin mold 300 in the root area, the upper and lower layers of the fiber fabric 100 at the end are back-drawn and misaligned until a specified number of layers are laid. Wherein, each fiber fabric 100 is laid in the length direction around the skin mold 300 in the circumferential direction. The shape of the skin mold 300 is consistent with the shape of the wind turbine blade.

[0108] In addition, the fiber fabric 100 after the stress relief treatment can be rolled into a roll for standby, directly transported to a blade production factory, and subjected to the next operation, such as the production of a skin product. The untreated fiber fabric can also be rolled into a roll for standby, placed on a dedicated device, unwound, and subjected to the stress relief treatment during the unwinding process to obtain the fiber fabric after the stress relief treatment, and then rolled again for standby.

[0109] FIG. 10 shows a third flowchart of a method for forming a wind power blade according to some embodiments of the present application; and FIG. 11 shows a second schematic view of a structure of a skin mold 300 according to some embodiments of the present application.

[0110] As shown in FIG. 10, in one specific embodiment of the present application, when the fiber fabric staggered layers 200 of the beam are prepared, steps S101 and S102 specifically include steps S113 and S114.

[0111] S113: performing stress relief treatment on at least one side edge of the fiber fabric 100 in the length direction;

[0112] When the fiber fabric at the beam position in the skin mold 300 is laid, the fiber fabric 100 with a corresponding length according to the length in the axis direction of the skin mold 300 is cut, and the target edge of the stress relief treatment is at least one of the opposite edges of the fiber fabric 100 in the length direction.

[0113] S114: laying the fiber fabric 100 in the skin mold 300 along the direction parallel to the axis of the skin mold 300, and performing back-off stagger of the fiber fabric 100 at the end side of the axis direction of the adjacent layers to form the fiber fabric staggered layers 200 of the beam.

[0114] As shown in FIG. 11, each long strip-shaped fiber fabric 100 is laid along the length direction of the skin mold 300; and a plurality of fiber fabrics 100 are laid in lap joint along the circumferential direction of the skin mold 300, so as to lay the fiber fabric 100 on the beam part of the skin mold 300. In the length direction, i.e., the axis direction of the skin mold 300, the two ends of the fiber fabric 100 of the upper layer and the two ends of the fiber fabric 100 of the lower layer are back-off staggered.

[0115] The fiber fabric staggered layers 200 of the beam and the fiber fabric 100 of the root can be laid simultaneously or sequentially, and the fiber fabric staggered layers 200 of the beam and the fiber fabric staggered layers 200 of the root can be lap jointed.

[0116] Further, in one specific embodiment of the present application, in order to reduce the stress level of the wind power 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. ​​​​​​​​

[0117] Fig. 12 shows a flowchart of a fourth method of forming a wind turbine blade according to some embodiments of the present application, and Fig. 13 shows a schematic view of a fabric block according to some embodiments of the present application.

[0118] As shown in Fig. 12, in order to improve the efficiency of the skin production, in another embodiment of the present application, the fiber fabric is laid in the target direction in the skin mold 300 according to step S102, and the fiber fabric on the end side of the adjacent layer axis direction is retracted and staggered to form the fiber fabric staggered layer 200, including steps S201 to S204.

[0119] S201: cutting the fiber fabric after stress reduction treatment into a specified size to obtain a fabric block 110;

[0120] Specifically, as shown in Fig. 10, according to the design size requirements of the wind turbine blade, the fiber fabric in roll is cut into fabric blocks 110 of specified length and packaged for use. The fabric blocks 110 of specified length are pre-cut, which is more efficient than cutting the size when laying the skin mold 300, and is convenient for the production of the blade root skin product and improves the efficiency of laying the fiber fabric in the skin mold 300.

[0121] S202: stacking and connecting the plurality of fabric blocks, and retraction and staggering the two ends of the axis direction of the adjacent two fabric blocks to form a stitched block 201.

[0122] That is, when stacking the fabric blocks, the two ends of the fabric blocks are retracted and staggered, and after stacking and connecting to the specified number of layers, the stitched block 201 is formed.

[0123] S203: laying the stitched block 201 in the target direction in the skin mold 300 to form the fiber fabric staggered layer 200.

[0124] For example, in other embodiments of the present application, as shown in Fig. 8, 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 be target edges, i.e. both are subjected to stress reduction treatment, and the adjacent fabric blocks 110 can be overlapped at the target edge position to form a fabric block layer. Of course, the adjacent fabric blocks 110 can also be overlapped in the body area. The plurality of fabric block layers are stacked to form a stitched block.

[0125] The 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, end sides of adjacent fiber fabric sheets are connected in staggered connection by backfolding, the fiber fabric sheet comprises a fiber fabric with a lap joint, the fiber fabric has a stress-reduced edge, the stress of the stress-reduced edge is less than the stress of the edge of the fiber fabric in an initial state, wherein the fiber fabric in the initial state is a conventional fiber fabric without stress-reducing measures. The skin is bonded to the surface of the blade body.

[0126] The wind turbine blade in the application can be realized by using the forming method of the wind turbine blade in the above-mentioned embodiments. The fiber fabric in the wind turbine blade in the application can be the fiber fabric subjected to stress reduction in the above-mentioned embodiments, and the stress-reduced edge of the fiber fabric in the wind turbine blade is the target edge of the fiber fabric subjected to stress reduction in the above-mentioned embodiments.

[0127] For example, the fiber fabric staggered layer 200 has a stress-reduced edge, i.e., a target edge 102, along the width direction, the thickness of the target edge 102 along the width direction is less than the thickness of the main body 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 body area 101; the width direction of the fiber fabric staggered layer 200 in the root area is perpendicular to the axis of the blade body.

[0128] 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 body 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 body 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.

[0129] In other embodiments of the application, the width of the stress-reduced edge ranges from 0.5 mm to 50 mm.

[0130] The above merely describes specific implementation manners of the application. It can be clearly understood by those skilled in the art that, for the convenience and brevity of description, the specific working processes of the above-described systems, modules and units can refer to the corresponding processes in the foregoing method embodiments, which will not be described herein. It should be understood that the protection scope of the application is not limited in this way, and any modification or replacement within the technical range disclosed by the application can be easily thought of by those skilled in the art, and these modifications or replacements shall be included in the protection scope of the application.

Claims

1. A method for forming a wind turbine blade, comprising: subjecting a target edge of a fiber fabric to a stress reduction treatment, wherein the stress reduction treatment comprises a thickness reduction treatment and / or a fiber continuity cutting treatment; laying the fiber fabric in a target direction in a skin mold with the fiber fabric on the end sides of the adjacent layer axis direction being back-lap staggered to form a fiber fabric staggered layer; laying a forming material on the fiber fabric staggered layer and injecting resin to cure to form a skin; bonding the skin and other blade components to a blade body to form a wind turbine blade.

2. A method of forming a wind turbine blade according to claim 1, wherein, The subjecting a target edge of a fiber fabric to a thickness reduction treatment comprises: reducing the thickness of the target edge in a direction from inside to outside along the target edge, so that the thickness of the target edge decreases in a decreasing trend.

3. A method of forming a wind turbine blade according to claim 1 or 2, wherein, The subjecting a target edge of a fiber fabric to a fiber continuity cutting treatment comprises: cutting the target edge into a zigzag shape in a width range of the target edge along a length direction of the target edge; or, subjecting the target edge to a scattering treatment; or, subjecting the target edge to a roughening treatment.

4. A method of forming a wind turbine blade according to claim 1, wherein, The subjecting a target edge of a fiber fabric to a stress reduction treatment when preparing a fiber fabric staggered layer of a blade root; laying the fiber fabric in a target direction in a skin mold with the fiber fabric on the end sides of the adjacent layer axis direction being back-lap staggered to form a fiber fabric staggered layer, comprises: subjecting at least one side edge of the fiber fabric in a width direction to a stress reduction treatment; laying the fiber fabric in the skin mold in a direction parallel to the axis of the skin mold in a width direction with the fiber fabric on the end sides of the adjacent layer axis direction being back-lap staggered and the fiber fabric being laid in a length direction on the skin mold in a circumferential direction to form a fiber fabric staggered layer of a blade root.

5. A method of forming a wind turbine blade according to claim 1, wherein, The subjecting a target edge of a fiber fabric to a stress reduction treatment when preparing a fiber fabric staggered layer of a beam; laying the fiber fabric in a target direction in a skin mold with the fiber fabric on the end sides of the adjacent layer axis direction being back-lap staggered to form a fiber fabric staggered layer, comprises: subjecting at least one side edge of the fiber fabric in a length direction to a stress reduction treatment; laying the fiber fabric in the skin mold in a direction parallel to the axis of the skin mold in a length direction with the fiber fabric on the end sides of the adjacent layer axis direction being back-lap staggered to form a fiber fabric staggered layer of a beam.

6. A method of forming a wind power blade according to claim 1 or 4 or 5, wherein, The laying the fiber fabric in a target direction in a skin mold with the fiber fabric on the end sides of the adjacent layer axis direction being back-lap staggered to form a fiber fabric staggered layer, comprises: cutting the fiber fabric after the stress reduction treatment into a specified size to obtain a fabric block; stacking and connecting multiple layers of the fabric blocks with the two ends of the axis direction of the fabric blocks of adjacent two layers being back-lap staggered to form a stitched block; and laying the stitched block in a target direction in a skin mold to form a fiber fabric staggered layer. 7.A wind turbine blade, comprising: A skin comprising a fibre fabric layup, wherein the fibre fabric layup comprises a plurality of fibre fabric plies, adjacent end sides of the fibre fabric plies are connected in a staggered overlap, the fibre fabric plies comprise an overlapping fibre fabric, the fibre fabric has a stress reducing edge, the stress of the stress reducing edge is less than the stress of the fibre fabric edge in an initial state; A blade body, the skin is bonded to a surface of the blade body.

8. A wind power blade according to claim 7, wherein, The thickness of the stress reducing edge tapers from inside to outside.

9. A wind power blade according to claim 7, wherein, The stress reducing edge comprises a tooth structure.

10. A wind power blade according to any of claims 7 to 9, wherein, The width of the stress reducing edge ranges between 0.5 mm and 50 mm.

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