Wind turbine blade core material design method and wind turbine blade

Abstract

The present application relates to the field of wind turbine blades, and discloses a method for designing a core material of a wind turbine blade and a wind turbine blade, wherein the method for designing a core material of a wind turbine blade includes: simulating the main beam of the wind turbine blade and the initial core material forming state, obtaining the first angle between the main beam and the initial core material; according to the first angle, determining the design angle between the initial core material and the bonding surface in contact with the main beam and the outer skin layer respectively, obtaining the designed core material, and when the designed core material is in the forming state, the first angle between the designed core material and the main beam is less than or equal to a threshold value. It is used to solve the resin-rich problem between the main beam and the core material, and the first angle between the initial core material and the main beam in the forming state is obtained by simulation, and the design angle between the initial core material and the bonding surface of the main beam and the outer skin is adjusted by the first angle to obtain the designed core material, so that there is no angle between the designed core material and the main beam in the forming state or the obtained angle is within the threshold range, thereby reducing the resin-rich situation and improving the forming quality of the wind turbine blade.

Description

Technical Field

[0001] The present application belongs to the field of wind turbine blades, and in particular, relates to a wind turbine blade core material design method and a wind turbine blade. Background Art

[0002] The main beam is the main load-bearing structure of the wind turbine blade, usually made of high-performance composite materials such as glass fiber reinforced plastic (GFRP) or carbon fiber reinforced plastic (CFRP). The main beam is generally arranged along the length of the wind turbine blade and bears most of the bending and shear loads that the wind turbine blade is subjected to during operation. Most of the existing main beams are pultruded main beams, which are mainly composed of pultruded sheets and uniaxial fabrics, and are formed by stacking multiple pultruded plates horizontally and interlayer fabrics vertically.

[0003] When the pultruded main beam is connected with the core material at the edge of the beam, the core material and the pultruded main beam cannot fit completely together, resulting in resin accumulation on the edge of the pultruded main beam after pouring, affecting the quality of the main beam. Summary of the invention

[0004] The embodiments of the present application provide a method for designing a core material of a wind turbine blade and a wind turbine blade, which can reduce the resin-rich problem between the main beam and the core material.

[0005] On the one hand, an embodiment of the present application provides a method for designing a core material of a wind turbine blade, comprising: simulating a forming state of a main beam and an initial core material of a wind turbine blade to obtain a first angle between the main beam and the initial core material; when the first angle is greater than a threshold value, determining, according to the first angle, a design angle between the fitting surfaces of the initial core material in contact with the main beam and an outer skin layer, respectively, to obtain a designed core material, wherein the angle between the designed core material and the main beam in the forming state is less than or equal to the threshold value.

[0006] According to the wind turbine blade core material design method provided in the embodiment of the present application, before the main beam and the initial core material of the simulated wind turbine blade are formed, it also includes: according to the second angle between the first working surface of the main beam of the wind turbine blade and the outer skin layer, determining the initial angle between the fitting surfaces where the initial core material contacts the main beam and the outer skin layer respectively, to obtain the initial core material, wherein the first working surface is the end surface where the main beam contacts the initial core material.

[0007] According to the wind turbine blade core material design method provided in an embodiment of the present application, the initial angles between the initial core material and the contact surfaces of the main beam and the outer skin respectively are determined according to the second angle between the first working surface of the main beam of the wind turbine blade and the outer skin layer to obtain the initial core material, including:

[0008] Determine a second angle between a first working surface of a main beam of a wind turbine blade and an outer skin layer; adjust an initial angle between the fitting surfaces of the initial core material contacting the main beam and the outer skin layer to be equal to the second angle, and obtain the initial core material.

[0009] According to the wind turbine blade core material design method provided in an embodiment of the present application, when the first angle is greater than a threshold value, the design angle between the fitting surfaces of the initial core material respectively contacting the main beam and the outer skin layer is determined according to the first angle to obtain the designed core material, including: when the first angle is greater than a threshold value, adjusting the initial angle to the design angle to obtain the designed core material, wherein the design angle is equal to the sum of the initial angle and the first angle.

[0010] According to the wind turbine blade core material design method provided in an embodiment of the present application, the simulation of the main beam and the initial core material forming state of the wind turbine blade to obtain the first angle between the main beam and the initial core material includes: constructing a combined model of the main beam and the initial core material laying state of the wind turbine blade; using the combined model to simulate the vacuum stress state to make the main beam and the initial core material in a formed state; and obtaining the first angle between the main beam and the initial core material under the vacuum stress state.

[0011] On the other hand, an embodiment of the present application also provides a wind turbine blade, comprising: an outer skin layer; a main beam, stacked and laid on the outer skin layer along the thickness direction; a designed core material, stacked and laid on the outer skin layer along the thickness direction, and arranged on the end side of the main beam along the chord direction, the wind turbine blade includes a laying state and a forming state; in the laying state, a side of the designed core material in contact with the outer skin layer has a second local gap with the outer skin layer, and a preset angle between the designed core material and the end side of the main beam with an opening facing the outer skin layer; in the forming state, the designed core material is respectively fitted to the outer skin layer and the main beam.

[0012] According to the wind turbine blade provided in the embodiment of the present application, the designed core material includes a first fitting surface and a second fitting surface at a designed angle, the first fitting surface is in contact with the outer skin layer, and the second fitting surface is in contact with the end face of the main beam, and in the laid state, the designed angle is greater than the second angle between the end face of the main beam and the outer skin layer.

[0013] According to the wind turbine blade provided in the embodiment of the present application, the designed core material is provided with first grooves spaced apart along the thickness direction, the notches of the first grooves face away from the outer skin layer, and the groove spacing of the first grooves in the laid state is greater than the groove spacing of the first grooves in the formed state.

[0014] According to the wind turbine blade provided in the embodiment of the present application, the designed core material includes a first core layer and a second core layer stacked along the thickness direction, the second core layer is placed on the side of the first core layer facing away from the outer skin layer, and the thickness of the second core layer tends to decrease along the chord direction from the main beam to the direction away from the main beam.

[0015] A method for designing a core material for a wind turbine blade and a wind turbine blade in an embodiment of the present application simulate a first angle generated between an initial core material and a main beam in a forming state, and adjust a design angle between the initial core material and the main beam and an outer skin bonding surface through the first angle to obtain a designed core material, so that there is no angle between the designed core material and the main beam in the forming state or the obtained angle is within a threshold range, thereby reducing the resin-rich situation and improving the forming quality of the wind turbine blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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.

[0017] Figure 1 A flow chart of a method for designing a core material for a wind turbine blade according to some embodiments of the present application;

[0018] Figure 2 This is a schematic diagram of the structure of a wind turbine blade in some embodiments of the present application;

[0019] Figure 3 for Figure 2 Schematic diagram of the main beam laying state in the wind turbine blade;

[0020] Figure 4 This is a schematic diagram of the initial core material laying state of some embodiments of the present application;

[0021] Figure 5 This is a partial schematic diagram of the initial core material forming state of some embodiments of the present application;

[0022] Figure 6 is a flow chart of a wind turbine blade core material design method provided by other embodiments of the present application;

[0023] Figure 7 It is a partial schematic diagram of the initial core material laying state of some other embodiments of the present application;

[0024] Figure 8 for Figure 2 Schematic diagram of the core material structure designed in wind turbine blades;

[0025] Fig. 9 is a flow chart of a wind turbine blade core material design method provided by some other embodiments of the present application;

[0026] Fig.10 is a flow chart of a wind turbine blade core material design method provided by some other embodiments of the present application;

[0027] Fig.11 A schematic diagram of the laying state of the core material designed for some embodiments of the present application;

[0028] Fig.12 This is a schematic diagram of the core material molding state of some embodiments of the present application.

[0029] Reference numerals:

[0030] 100: main beam; 101: outer skin layer; 102: first working surface; 104: second working surface; 103: first local gap; 110: first angle; 120: designed angle; 200: initial core material; 201: second groove; 310: first core layer; 320: second core layer; 300: designed core material; 301: preset angle; 302: first fitting surface; 303: second fitting surface; 304: first groove; 305: second local gap; A: second angle. DETAILED DESCRIPTION

[0031] 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.

[0032] 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.

[0033] Wind turbine blades are one of the key components of wind turbine generators. The main function of wind turbine blades is to capture wind energy and convert it into mechanical energy, which is then converted into electrical energy through generators. Wind turbine blades are usually composed of outer shells, main beams, webs and other parts. The outer shell is generally made of composite materials with the characteristics of high strength, light weight and corrosion resistance. The main beam is the main load-bearing structure of the wind turbine blade and is usually made of high-performance composite materials such as glass fiber reinforced plastic (GFRP) or carbon fiber reinforced plastic (CFRP). The main beam is generally arranged along the length of the wind turbine blade and bears most of the bending and shear loads that the wind turbine blade is subjected to during operation.

[0034] The main forming methods of wind turbine blade beams include the following:

[0035] Vacuum infusion molding: The fiber-reinforced material is laid in the mold, and the resin is infused into the mold through vacuum, so that the resin fully infiltrates the fiber-reinforced material, and then solidifies and forms. This molding method can produce high-quality main beams, but it requires the use of special equipment and molds, which is costly.

[0036] Prepreg molding: Fiber-reinforced materials (prepregs) pre-impregnated with resin are laid in a mold and then cured and molded by heating and pressurizing. Prepreg molding can produce high-strength, high-quality main beams, but it requires the use of specialized prepregs and equipment, which is costly.

[0037] Pultrusion: The fiber-reinforced material is passed through a pultrusion die, impregnated with resin and cured to form a continuous profile. Pultrusion can produce a high-strength, high-rigidity main beam with high production efficiency and low cost. This molding method is currently one of the mainstream technologies for manufacturing wind turbine blade main beams.

[0038] However, when the pultruded main beam is connected with the core material at the beam edge, the core material and the main beam cannot be completely fitted together, resulting in resin accumulation at the beam edge after infusion, affecting the quality of the main beam. In order to solve the resin accumulation problem, the existing technology uses the method of laying the core material after the main beam is placed, and filling the gap area between the core material and the main beam with core material strips. After filling with the core material strips, an invisible gap will still be formed between the lower core material and the main beam, and the problem of resin-rich outer skin beam edge will still occur after the blade is demoulded.

[0039] In order to solve the problems in the prior art, the present application provides a method for designing a core material of a wind turbine blade and a wind turbine blade. Figures 1 to 12 As shown, the following first introduces the wind turbine blade core material design method provided in the embodiment of the present application.

[0040] like Figures 1 to 8 As shown, an embodiment of the present invention provides a method for designing a core material of a wind turbine blade, comprising steps S1 to S3.

[0041] S1: According to the second angle A between the first working surface 102 of the main beam 100 of the wind turbine blade and the outer skin layer 101, the initial angle between the fitting surfaces of the initial core material 200 contacting the main beam 100 and the outer skin layer 101 respectively is determined to obtain the initial core material 200, wherein the first working surface 102 is the end surface where the main beam 100 contacts the initial core material 200.

[0042] S2: simulating the forming state of the main beam 100 and the initial core material 200 of the wind turbine blade to obtain a first angle 110 between the main beam 100 and the initial core material 200.

[0043] S3: When the first angle 110 is greater than a threshold value, the design angle 120 between the fitting surfaces of the initial core material 200 contacting the main beam 100 and the outer skin layer 101 is determined according to the first angle 110 to obtain the designed core material 300. When the designed core material 300 is in a formed state, the angle between it and the main beam 100 is less than or equal to the threshold value.

[0044] Regarding step S1.

[0045] like Figure 2 As shown, a designed core material 300 is arranged on the side of the main beam 100 along the chord direction. The arrangement of the designed core material 300 can significantly enhance the bending resistance of the wind turbine blade, so that the blade is not easily deformed when subjected to wind force, thereby ensuring the stability and service life of the blade. As an important component of the blade, the designed core material 300 can share the load borne by the main beam 100 and improve the overall bearing capacity of the blade. The pultruded main beam 100 is composed of pultruded sheets and uniaxial fabrics, and is formed by a plurality of pultruded plates being stacked and laid vertically in a cross-laminated manner with interlayer fabrics.

[0046] like Figure 3 As shown, the outer skin layer 101 is first laid on the shell mold of the wind turbine blade, and the main beam 100 is laid on the outer skin layer 101 and bent along the curvature of the shell mold. After the main beam 100 is fixed, the two ends of the main beam 100 along the chord direction form an angle with the outer skin layer 101, that is, the second angle A.

[0047] like Figure 3 and Figure 4As shown, the initial core material 200 is arranged at both ends of the main beam 100, the end fitting surface of the initial core material 200 contacts the main beam 100, and the bottom fitting surface of the initial core material 200 contacts the outer skin layer 101. In the laying state of the wind turbine blade, the end fitting surface of the initial core material 200 contacts and fits with the main beam 100, and the bottom fitting surface of the initial core material 200 contacts but does not completely fit with the outer skin layer 101. Based on the installation position of the initial core material 200, the initial angle formed by the end and bottom fitting surfaces of the initial core material 200 is determined by the angle of the second angle A, and then the specific structure and size of the initial core material 200 are determined.

[0048] Regarding step S2.

[0049] The determined initial core material 200 and the main beam 100 are laid to simulate the actual working conditions during forming, so that the initial core material 200 and the main beam 100 are in a forming state, and the adaptability of the initial core material 200 and the main beam 100 is verified. Figure 5 As shown, since the initial core material 200 and the main beam 100 are both subjected to external force during solidification, the initial core material 200 and the main beam 100 undergo adaptive deformation under the action of the external force, so that an angle, namely a first angle 110, is generated between the main beam 100 and the initial core material 200.

[0050] Regarding step S3.

[0051] When the first angle 110 is greater than the threshold, it is considered that the first angle 110 is too large, and resin-rich phenomenon will occur during the molding of the wind turbine blade, thereby affecting the molding quality of the wind turbine blade. The initial angle of the initial core material 200 is re-determined according to the position and size of the first angle 110, for example, the initial angle is increased, and the increased angle can be half or one-third of the first angle 110. The design angle 120 is updated, and the updated design core material 300 is obtained based on the design angle 120. When the design core material 300 is in the molding state, the angle between the main beam 100 is less than or equal to the threshold, thereby solving the problem of resin-rich between the initial core material 200 and the main beam 100 during the molding of the wind turbine blade, reducing the generation of resin-rich defects between the initial core material 200 and the main beam 100, reducing defect repair, improving the molding efficiency of the wind turbine blade, improving the molding quality of the wind turbine blade, and reducing the manufacturing cost of the wind turbine blade. The initial core material 200 can obtain the final design core material 300 by adjusting the initial angle multiple times.

[0052] In addition, in another embodiment of the present application, the initial core material 200 may have an existing core material size and structure, and there is no need to redesign and confirm the initial angle of the initial core material 200. Therefore, the wind turbine blade core material design method of this embodiment may only include steps S2 and S3.

[0053] Of course, in other embodiments of the present application, the size and structure of the initial core material 200 may be set based on the experience of the staff, or the initial angle may be obtained in other ways.

[0054] like Figures 1 to 7 As shown, in order to improve the design efficiency, in one embodiment of the present application, step S1 of the above embodiment specifically includes steps S11 and S12.

[0055] S11: Determine a second angle A between the first working surface 102 of the main beam 100 of the wind turbine blade and the outer skin layer 101 .

[0056] S12: Adjust the initial angles between the contact surfaces of the initial core material 200 and the main beam 100 and the outer skin layer 101 to be equal to the second angle A, so as to obtain the initial core material 200.

[0057] Regarding step S11.

[0058] The second angle A between the first working surface 102 of the main beam 100 of the wind turbine blade and the outer skin layer 101 can be obtained through model simulation or actual surveying and mapping. Since the outer skin layer 101 has a certain curvature, the angle between the first working surface 102 and the outer skin layer 101 can be the angle between the first working surface 102 and the tangent at the contact point between the end side of the main beam 100 and the outer skin layer 101. Alternatively, the main beam 100 includes a second working surface 104 in contact with the outer skin layer 101, and the angle between the first working surface 102 and the outer skin layer 101 can be equal to the angle between the tangent at the intersection of the second working surface 104 and the first working surface 102 and the first working surface 102 after the main beam 100 is installed on the outer skin layer 101.

[0059] Regarding step S12.

[0060] like Figure 7 As shown, the initial angles between the bonding surfaces of the initial core material 200 in contact with the main beam 100 and the outer skin layer 101 are equal to the second angle A, and the initial core material 200 is obtained. When the initial core material 200 is laid on the end side of the main beam 100, the end bonding surface of the initial core material 200 is basically in contact with the first working surface 102. Since the bottom bonding surface of the initial core material 200 is in contact with the outer skin layer 101 but there is a gap, there is a gap between the middle of the bottom bonding surface and the outer skin layer 101. After the initial core material 200 is subjected to force, the bottom bonding surface of the initial core material 200 is completely in contact with the outer skin layer 101. Therefore, a second angle A with an opening facing away from the outer skin layer 101 is formed between the initial core material 200 and the first working surface 102 of the main beam 100.

[0061] Furthermore, if Figures 1 to 8As shown, in the embodiment of the present application, step S3 specifically includes step S13.

[0062] S13: When the first angle 110 is greater than a threshold, the initial angle is adjusted to a design angle 120 to obtain a designed core material 300 , wherein the design angle 120 is equal to the sum of the initial angle and the first angle 110 .

[0063] That is, the forming state of the initial core material 200 and the main beam 100 when the initial angle is equal to the second angle A is simulated to obtain the second angle A. The sum of the initial angle and the second angle A is the design angle, and then the updated design core material 300 is obtained. The design angle is equal to the sum of the initial angle and the first angle 110. It is possible to obtain the effect that the first angle 110 between the design core material 300 and the main beam 100 is less than or equal to the threshold value when the design core material 300 is in the forming state without multiple simulation verifications and repairs, thereby simplifying the design process and improving the design efficiency.

[0064] like Figures 1 to 9 As shown, in an optional embodiment of the present application, step S2 specifically includes steps S21 to S23.

[0065] S21: constructing a combined model of the main beam 100 and the initial core material 200 of the wind turbine blade in a laying state.

[0066] S22: simulating a vacuum stress state using a combined model to put the main beam 100 and the initial core material 200 in a forming state during forming.

[0067] S23: Obtaining a first angle 110 between the main beam 100 and the initial core material 200 in a vacuum stress state.

[0068] Specifically, the combined model is constructed to more accurately simulate the laying of the main beam 100 and the initial core material 200 in actual production. By considering the two together, their interaction and influence in the forming process can be better analyzed. The combined model can include information such as the geometry, material properties, and laying method of the main beam 100, the initial core material 200, and the outer skin layer 101, providing a basis for subsequent simulations. For example, Figure 5 As shown, the initial core material 200 includes second grooves 201 spaced apart in the thickness direction, the second grooves 201 are used for guiding, and the notches of the second grooves 201 face away from the outer skin layer 101. In the simulation process of the vacuum stress state, the changes of the second grooves 201 after stress are taken into account, as well as the influence on the shape of the initial core material 200. For example, in the vacuum stress state, the opening of the second groove 201 changes from the initial 2 mm to 1 mm.

[0069] In actual production, wind turbine blades are usually formed in a vacuum environment. Therefore, the simulation of the vacuum stress state can more realistically reflect the actual situation in the molding process. The simulation of the vacuum stress state can feedback the various forces, deformation and relative positions of the main beam 100 and the initial core material 200 under the vacuum environment. In one embodiment, the simulation method of finite element analysis can be used to simulate the vacuum stress state of the combined model. The simulation of the vacuum stress state is performed by using the finite element analysis method. The specific process can be to input the relevant material parameters, boundary conditions and stress information in the finite element analysis program, and approximately solve the various forces, deformation and relative positions of the main beam 100 and the initial core material 200, and obtain the response of the combined model under the vacuum stress state. Since the simulation of the various forces, deformation and relative positions of the main beam 100 and the initial core material 200 of the wind turbine blade under a vacuum environment by the finite element analysis method is a prior art, it will not be repeated here.

[0070] The first angle 110 between the main beam 100 and the initial core material 200 under the vacuum stress state can be obtained through direct feedback of the simulation of the combined model.

[0071] Of course, in other embodiments of the present application, the first angle 110 under actual working conditions can be obtained by laying the main beam 100 and the core material and other wind turbine blade molding materials in the shell mold, which serves as a basis for the subsequent wind turbine blade molding.

[0072] like Figures 1 to 10 As shown, in a specific embodiment of the present application, in order to improve the authenticity of the simulation, step S21 includes:

[0073] S211: construct structural models of the main beam 100, the initial core material 200 and the outer skin layer 101 of the wind turbine blade respectively.

[0074] S212 : Laying the structural model of the main beam 100 and the initial core material 200 to the structural model of the outer skin layer 101 .

[0075] S213: Adjust the initial core material 200 to fit the end side of the main beam 100, so that the initial core material 200 is in contact with the outer skin layer 101 to form a first local gap 103, thereby obtaining a combined model.

[0076] To construct the structural model of the main beam 100 of the wind turbine blade, it is necessary to first determine the dimensions of the main beam 100, including height, width, and thickness. Use 3D modeling software such as SolidWorks and CATIA to create a geometric model of the main beam 100. Select the material of the main beam 100, such as carbon fiber or glass fiber, and define the material properties in the 3D modeling software, including density, elastic modulus, and Poisson's ratio. Draw the cross-sectional shape of the main beam 100 according to the determined dimensions of the main beam 100, and stretch it along the length direction of the wind turbine blade to form a 3D model.

[0077] Construct a structural model of the initial core material 200 of the wind turbine blade, select the type of the initial core material 200, for example, PVC foam, Balsa wood, and PVC foam is selected in this application. Determine the thickness of the initial core material 200, and use a 3D modeling software to create a geometric model of the initial core material 200. Define the material properties of the initial core material 200 in the 3D modeling software, including density, shear modulus, and compression strength.

[0078] Construct a structural model of the outer skin layer 101, select the material of the outer skin layer 101, such as glass fiber, carbon fiber. Determine the thickness and shape of the outer skin layer 101. Use 3D modeling software to create a geometric model of the outer skin layer 101, and define the material properties of the outer skin layer 101 in the 3D modeling software, including density, elastic modulus, and Poisson's ratio.

[0079] Place the constructed structural models of the main beam 100 and the initial core material 200 on the structural model of the outer skin layer 101 to simulate the laying process in actual production. Determine the position and orientation of the structural models of the main beam 100 and the initial core material 200 on the structural model of the outer skin layer 101. Determine boundary conditions, such as fixed ends and free ends. Use positioning constraints and alignment tools to accurately lay out the model. During the laying process, determine the contact relationship and interaction between the main beam 100 and the outer skin layer 101 of the initial core material 200. For example, the friction and adhesion factors between the main beam 100 and the initial core material 200 and the outer skin layer 101.

[0080] Adjusting the end-side fit of the initial core material 200 and the main beam 100 can ensure a tight connection between the two, simulating the assembly situation in actual production. The first local gap 103 is formed after the initial core material 200 contacts the outer skin layer 101 to take into account the incomplete fit that may occur in actual production and increase the authenticity of the simulation.

[0081] Continue to refer Figure 7Since the bottom fitting surface of the initial core material 200 is a straight surface, and the outer skin layer 101 is curved when fitting the shell mold, the initial core material 200 contacts the outer skin layer 101 at both ends, and a gap is formed in the middle. Since the initial angle between the end fitting surface and the bottom fitting surface of the initial core material 200 is equal to the second angle A, the end fitting surface of the initial core material 200 contacts and fits with the first working surface 102 of the main beam 100 during the laying stage. Figure 3 and Figure 5 Since the initial core material 200 has the second groove 201 for guiding flow, under the vacuum stress state, the initial core material 200 is force-fitted to the outer skin layer 101, and the opening of the second groove 201 is squeezed, forming a first angle 110 between the end fitting surface of the initial core material 200 and the first working surface 102 of the main beam 100, and the initial angle is squeezed and reduced under the vacuum stress state, completing the simulation under the vacuum stress state.

[0082] like Figures 1 to 12 As shown, the embodiment of the present application also provides a wind turbine blade, comprising: an outer skin layer 101, a main beam 100 and a designed core material 300; the main beam 100 is stacked and laid on the outer skin layer 101 in the thickness direction; the designed core material 300 is stacked and laid on the outer skin layer 101 in the thickness direction, and is arranged at the end side of the main beam 100 along the chord direction, and the wind turbine blade includes a laying state and a forming state; in the laying state, the side of the designed core material 300 in contact with the outer skin layer 101 has a second local gap 305 with the outer skin layer 101, and the designed core material 300 and the end side of the main beam 100 have a preset angle 301 with the opening facing the outer skin layer 101; in the forming state, the designed core material 300 is respectively fitted with the outer skin layer 101 and the main beam 100. The designed core material 300 in this embodiment can be obtained by the wind turbine blade core material design method of the above embodiment.

[0083] After the laying state is completed, the wind turbine blade enters the forming state. The laying process includes: laying the outer skin layer 101 into the shell mold, laying the pultruded main beam 100 in layers on the outer skin layer 101 along the thickness direction, and laying the designed core material 300 in layers on the outer skin layer 101 along the thickness direction, and arranging it on the end side of the main beam 100 along the chord direction. After the laying of the designed core material 300 is completed, there is a preset angle 301 between the designed core material 300 and the end side of the main beam 100, with the opening facing the outer skin layer 101, and there is a second local gap 305 between the designed core material 300 and the middle part of the outer skin layer 101. The angle of the preset angle 301 can be equal to the angle of the first angle 110.

[0084] In order to improve the matching accuracy between the outer skin layer 101, the main beam 100 and the designed core material 300, the main beam 100 is tied and fixed with tensioning and conforming tooling, and the main beam 100 is lifted steadily by an overhead crane to prevent the main beam 100 from causing the gap between the plates of the pultruded main beam 100 due to improper transportation and forming a misaligned step on the side of the main beam 100. After the main beam 100 is positioned, the main beam 100 is adjusted so that the single gap between the plates does not exceed 5mm and the total gap does not exceed 10mm. After the exposed size of the interlayer cloth of the main beam 100 is adjusted to 5-10mm, the designed core material 300 is laid in line with the front and rear edges of the main beam 100.

[0085] That is to say, Figure 8 and Fig.11 As shown, the designed core material 300 includes a first fitting surface 302 and a second fitting surface 303 at a designed angle 120, the first fitting surface 302 contacts the outer skin layer 101, and the second fitting surface 303 contacts the end surface of the main beam 100. In the laying state, the first fitting surface 302 contacts the outer skin layer 101 on both sides along the chord direction, and has a second local gap 305 in the middle due to the curvature of the outer skin layer 101. The side of the second fitting surface 303 away from the outer skin layer 101 contacts the first working surface 102 of the main beam 100, and there is a gap between the side of the second fitting surface 303 close to the outer skin layer 101 and the first working surface 102, that is, a preset angle 301 is formed.

[0086] Of course, the laying process of wind turbine blades also includes the laying and installation of structures such as lightning protection equipment and inner skin layers.

[0087] The molding process includes the installation of vacuum equipment, vacuuming the laid layer structure, and infusing resin. During the vacuuming process, the core material 300, the main beam 100, the inner skin layer and other structures are subjected to extrusion force, so that the first fitting surface 302 of the core material 300 fits with the outer skin layer 101, eliminating or reducing the second local gap 305. The second fitting surface 303 fits with the first working surface of the main beam 100, eliminating or reducing the preset angle 301. In this way, the core material 300 and the main beam 100 are highly fitted, the generation of resin-rich defects on the side of the main beam 100 is reduced, the number of defect repairs is reduced, the blade molding efficiency is reduced, and the blade manufacturing cost is reduced.

[0088] Furthermore, in an embodiment of the present application, the designed core material 300 includes a first fitting surface 302 and a second fitting surface 303 at a designed angle 120. In the laid state, the designed angle 120 is greater than the second angle A between the end face of the main beam 100 and the outer skin layer 101.

[0089] By making the design angle 120 larger than the second angle A between the end face of the main beam 100 and the outer skin layer 101, the core material 300 and the main beam 100 can be better fitted after being subjected to force in the molding state. In the molding state, the angle between the first fitting surface 302 and the second fitting surface 303 is squeezed to be smaller than the design angle 120, and the design angle 120 is larger than the second angle A between the end face of the main beam 100 and the outer skin layer 101 to provide a margin for the downward bending of the core material 300 fitting the outer skin layer 101, thereby ensuring that the core material 300 fits better with the main beam 100 and the outer skin layer 101, and reducing the defects of rich resin.

[0090] For example, the designed angle 120 may be equal to the sum of the second angle A and the first angle 110 obtained in the above embodiment.

[0091] Continue to refer Figures 8 to 12 In some embodiments of the embodiments of the present application, the core material 300 is designed to include a first core layer 310 and a second core layer 320 stacked along the thickness direction. The second core layer 320 is placed on the side of the first core layer 310 that is away from the outer skin layer 101. Along the chord direction from the main beam 100 to the direction away from the main beam 100, the thickness of the second core layer 320 tends to decrease.

[0092] The first core layer 310 and the second core layer 320 may also include multiple layers to better match the end side of the pultruded main beam 100 and reduce the matching gap. In addition, the thickness of the second core layer 320 has a decreasing trend to allow the core material 300 to transition slowly and avoid excessive concentrated stress caused by sudden changes.

[0093] For example, the slope angle of the second core layer 320 facing away from the first core layer 310 is 1:5. The second core layer 320 is arranged in layers at a thickness exceeding 30 mm.

[0094] During the bonding and fixing process, after the main beam 100 is placed, the first core layer 310 is fixed with glue by spraying. A small amount of glue is sprayed on the first core layer 310, and the area of ​​the first core layer 310 close to the main beam 100 is held, and the main beam 100 is pressed firmly. The first core layer 310 is laid downwardly perpendicular to the exposed interlayer cloth of the main beam 100 to prevent the exposed interlayer cloth from folding and stacking, which affects the matching of the first core layer 310 with the edge of the pultruded beam. After confirming that the gap is ≤2mm, the first core layer 310 is pressed and fixed to the outer skin layer 101.

[0095] After the first core layer 310 is fixed, spray glue locally according to the width of the second core layer 320, and then fit the second core layer 320 to the main beam 100, vertically squeeze the exposed interlayer fabric on the side of the main beam 100, and lay the second core layer 320 downward. After the second core layer 320 is in place, use the palm of your hand to pat it down in the horizontal plane perpendicular to the main beam 100 to ensure that the second core layer 320 is firmly attached to the main beam 100 and the first core layer 310, and the gap with the main beam 100 is ≤2mm. Finally, the edge of the inclined surface of the second core layer 320 is connected and fixed to the first core layer 310 using resin nails.

[0096] In an optional embodiment of the present application, the core material 300 is designed to be provided with first grooves 304 spaced apart in the thickness direction, the notches of the first grooves 304 are facing away from the outer skin layer 101, and the groove spacing of the first grooves 304 in the laying state is greater than the groove spacing of the first grooves 304 in the forming state. In other words, the first grooves 304 are squeezed in the forming state. The first grooves 304 can be guide grooves of the core material 300 itself, or other functional grooves can be provided.

[0097] For example, the spacing between adjacent first grooves 304 on the core material 300 is designed to be 30±2 mm, the groove gap width is 2 mm, the groove width is 0.7-1 mm, and the edge thickness is 2±0.5 mm. In the molding state, the groove gap width is reduced to 1 mm.

[0098] 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 designing a core material of a wind turbine blade, characterized in that: include: Simulating the forming state of the main beam and the initial core material of the wind turbine blade to obtain a first angle between the main beam and the initial core material; When the first angle is greater than a threshold value, the design angle between the fitting surfaces of the initial core material and the main beam and the outer skin layer is determined according to the first angle to obtain the designed core material. When the designed core material is in a formed state, the angle between the designed core material and the main beam is less than or equal to the threshold value.

2. The method for designing a core material of a wind turbine blade according to claim 1, characterized in that: Before simulating the main beam and the initial core material forming state of the wind turbine blade, the method further includes: According to the second angle between the first working surface of the main beam of the wind turbine blade and the outer skin layer, the initial angle between the fitting surfaces where the initial core material contacts the main beam and the outer skin layer respectively is determined to obtain the initial core material, wherein the first working surface is the end surface where the main beam contacts the initial core material.

3. The method for designing a core material of a wind turbine blade according to claim 2, characterized in that: The method of determining the initial angles between the contact surfaces of the initial core material and the main beam and the outer skin respectively according to the second angle between the first working surface of the main beam of the wind turbine blade and the outer skin layer to obtain the initial core material comprises: Determine a second angle between a first working surface of a main beam of the wind turbine blade and an outer skin layer; The initial angles between the initial core material and the bonding surfaces respectively contacting the main beam and the outer skin layer are adjusted to be equal to the second angle to obtain the initial core material.

4. The method for designing a core material of a wind turbine blade according to claim 3, characterized in that: When the first angle is greater than a threshold value, determining the design angles between the bonding surfaces of the initial core material and the main beam and the outer skin layer respectively according to the first angle to obtain the designed core material, comprising: When the first angle is greater than a threshold, the initial angle is adjusted to a design angle to obtain a designed core material, wherein the design angle is equal to the sum of the initial angle and the first angle.

5. The method for designing a core material of a wind turbine blade according to claim 1, characterized in that: The simulating the forming state of the main beam and the initial core material of the wind turbine blade to obtain the first angle between the main beam and the initial core material includes: Construct a combined model of the main beam and initial core material laying state of the wind turbine blade; The combined model is used to simulate the vacuum stress state, so as to put the main beam and the initial core material into a forming state; A first angle between the main beam and the initial core material in a vacuum stress state is obtained.

6. A wind turbine blade, characterized in that: include: Outer skin layer; A main beam is laid in layers along the thickness direction to the outer skin layer; Designing a core material, laying it on the outer skin layer in a stacked manner along the thickness direction, and arranging it on the end side of the main beam along the chord direction, wherein the wind turbine blade includes a laying state and a forming state; In the laying state, a second local gap is provided between the side of the designed core material in contact with the outer skin layer and the outer skin layer, and a preset angle is provided between the designed core material and the end side of the main beam with the opening facing the outer skin layer; in the forming state, the designed core material is respectively fitted to the outer skin layer and the main beam.

7. The wind turbine blade according to claim 6, characterized in that: The designed core material includes a first fitting surface and a second fitting surface at a designed angle, the first fitting surface is in contact with the outer skin layer, and the second fitting surface is in contact with the end surface of the main beam. In the laid state, the designed angle is greater than the second angle between the end surface of the main beam and the outer skin layer.

8. The wind turbine blade according to claim 6, characterized in that: The designed core material is provided with first grooves spaced apart along the thickness direction, the groove openings of the first grooves face away from the outer skin layer, and the groove spacing of the first grooves in the laying state is greater than the groove spacing of the first grooves in the forming state.

9. The wind turbine blade according to claim 6, characterized in that: The designed core material includes a first core layer and a second core layer stacked along the thickness direction, the second core layer is placed on the side of the first core layer facing away from the outer skin layer, and the thickness of the second core layer tends to decrease along the chord direction from the main beam to the direction away from the main beam.

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