Basalt fiber wind power blade and preparation method thereof

Abstract

The present application relates to the technical field of wind power blade processing, and discloses a basalt fiber wind power blade and a preparation method thereof, which comprises a hub and a blade assembly, the blade assembly is fixedly assembled on the outer side of the hub and is annularly and equidistantly distributed, the blade assembly is provided with not less than three groups, an internal reinforcing assembly is fixedly installed inside the blade assembly, the blade assembly comprises a blade, a blade root, a blade leading edge, a butt joint adhering surface, a basalt fiber prefabricated protection strip, a positioning boss, a clamping groove and a dismounting operation groove, and the blade is respectively provided with a blade leading edge and a blade trailing edge along the two sides in the span direction. In the present application, a basalt stitching grid interlayer toughening structure is adopted, the interlayer fracture toughness of the beam cap is significantly improved without changing the main beam main body bearing structure, the interlayer crack propagation under alternating load is effectively blocked, the technical difficulties of the traditional basalt blade main beam being prone to delamination and poor fatigue resistance are solved, and the service life of the blade is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of wind turbine blade processing technology, and in particular to basalt fiber wind turbine blades and their preparation methods. Background Technology

[0002] As the core load-bearing and aerodynamic power-generating component of wind turbine generators, the structural strength, fatigue resistance, weather resistance, erosion resistance, and lightweight level of wind turbine blades directly determine the operational stability and service life of wind turbine generators. Currently, most commercial wind turbine blades are made of glass fiber composite materials. Glass fiber composite materials have defects such as insufficient salt spray resistance, high temperature resistance, and aging resistance. Under complex working conditions such as offshore, high altitude, and sandstorms, they are prone to defects such as surface erosion, interlayer delamination, interface debonding, and fatigue cracking, resulting in high operation and maintenance costs and limited service life of the entire unit.

[0003] Basalt fiber, with its excellent weather resistance, corrosion resistance, fatigue resistance, and high cost-effectiveness, is gradually becoming a new type of reinforcing material for wind turbine blades. Compared with traditional fiberglass materials, basalt fiber has better resistance to rain erosion, UV aging, high temperature, and salt spray, making it suitable for complex and harsh wind power operating conditions. However, existing basalt fiber wind turbine blade structures and manufacturing processes still have defects: traditional blade main beams use a pure unidirectional basalt cloth flat-lay composite structure, with interlayer bonding relying solely on the resin matrix. This results in low interlayer fracture toughness, and when the blade is subjected to alternating flapping, swaying, and bending loads for a long time, microcracks easily initiate and continue to propagate between the main beam layers, causing delamination failure and seriously affecting the structural safety of the blade. The blade web and main beam cap are mostly connected by simple adhesive bonding, with the interface relying solely on the resin adhesive layer to withstand shear and delamination. Under alternating loads, the adhesive layer is prone to cracking and interface debonding, resulting in poor structural connection reliability. Traditional blades with uniform density core material and no perforation reinforcement structure design cannot match the spanwise gradient load distribution of the blade, leading to insufficient root stiffness and excessive redundant weight at the tip. Furthermore, stress concentration is significant after perforation of the web, making it prone to local buckling and cracking. The leading edge of the blade is the area most severely affected by aerodynamic erosion. Traditional blades often use surface coatings for protection, but coating wear and peeling make subsequent repairs difficult, requiring overall grinding and repair of the entire blade body, resulting in high maintenance costs and low repair efficiency. Existing blade manufacturing process parameters are crude, with no precise quantitative control over layup ratios, resin impregnation, curing temperature rise, and assembly gaps. This easily leads to molding defects such as bubbles, dry areas, and micropores inside the blade, resulting in poor product consistency and structural stability. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide basalt fiber wind turbine blades and their preparation method to solve the problems of easy delamination between layers, easy debonding at the interface, poor leading edge erosion resistance, poor structural load matching, low molding accuracy, and high operation and maintenance costs of existing basalt fiber blades.

[0005] To address the aforementioned problems, the present invention is implemented through the following technical solution.

[0006] Basalt fiber wind turbine blades and their manufacturing method, comprising: a hub and a blade assembly, wherein the blade assembly is fixedly assembled on the outside of the hub and is distributed in a ring at equal intervals, the blade assembly is provided in no less than three sets, and an internal reinforcement component is fixedly installed inside the blade assembly, the blade assembly includes a blade, a blade root, a blade leading edge, a mating surface, a basalt fiber prefabricated protective strip, a positioning boss, a locking groove and a disassembly and assembly operation groove, and the blade has a blade leading edge and a blade trailing edge respectively provided on both sides along the span.

[0007] Preferably, the outer side of the leading edge of the blade is provided with a mating surface, and the leading edge of the blade is fitted with a basalt fiber prefabricated protective strip through the mating surface, positioning boss and locking groove.

[0008] Preferably, the basalt fiber prefabricated protective strip has an arc-shaped cross-section, and a positioning boss is integrally provided at the inner edge of the basalt fiber prefabricated protective strip. A locking groove matching the positioning boss is opened on the mating surface of the leading edge of the blade. The positioning boss is limited and locked inside the locking groove. A disassembly and assembly operation groove is opened at the end of the basalt fiber prefabricated protective strip corresponding to the positioning boss. The disassembly and assembly operation groove is opened horizontally at equal intervals. The disassembly and assembly operation groove is connected to the locking groove.

[0009] Preferably, the internal reinforcement components include a beam cap, a basalt fiber cloth layer, a basalt stitched mesh toughening layer, a shear-resistant web, a foam sandwich layer, a snap-fit ​​tenon, an inverted trapezoidal dovetail assembly groove, a weight-reducing process hole, and a reinforcing frame, wherein the beam cap extends along the spanwise direction of the blade.

[0010] Preferably, the beam cap is disposed at the upper and lower ends of the inner side of the blade. The beam cap is formed by stacking multiple layers of basalt fiber cloth. A basalt stitched mesh toughening layer is laid every few layers of basalt fiber cloth, and the basalt stitched mesh toughening layer is sandwiched between adjacent basalt fiber cloth layers.

[0011] Preferably, the shear web is vertically fixed between the beam caps, and the shear web and the beam caps enclose the internal bearing cavity of the blade. A foam core layer is sandwiched in the middle of the shear web. The upper and lower ends of the shear web are integrally provided with locking tenons. An inverted trapezoidal dovetail assembly groove is opened at the docking position of the beam cap and the shear web. The locking tenon is limited and fitted into the inverted trapezoidal dovetail assembly groove to form a mechanical anchoring structure.

[0012] Preferably, a plurality of weight-reduction process holes are provided through the middle of the shear web plate, and the weight-reduction process holes are arranged equidistantly in the transverse direction. A reinforcing frame is fixedly installed on the outer side of the shear web plate and around the edge of the weight-reduction process holes. The reinforcing frame is arranged around the edge of the weight-reduction process holes, and the upper and lower ends of the reinforcing frame abut against the beam cap.

[0013] A method for preparing basalt fiber wind turbine blades includes the following steps:

[0014] S1. Multi-parameter matching prefabrication: Based on the blade spanwise stiffness gradient model, core components are prefabricated in sections, forming a beam cap mold with an inverted trapezoidal dovetail assembly groove, and a shear web mold with locking tenons and arrayed weight-reduction process holes; basalt fiber prefabricated protective strips are prepared using a molding process, and a gradient density foam sandwich layer and a closed-loop reinforcing frame are processed in conjunction. The dimensional processing accuracy of each component is controlled within ±0.05mm~±0.2mm, and the assembly gap is preset within the range of 0.2~1mm;

[0015] S2. Layered toughening gradient lay-up curing: Basalt fiber cloth layers with a surface density of 800-1400 g / m² are laid layer by layer in the beam cap mold. A layer of 80-200 g / m² basalt stitched mesh toughening layer is laid every 3-8 layers of basalt fiber cloth, forming an alternating composite structure of main load-bearing layer and toughening transition layer. Vacuum flow technology is adopted, with the vacuum degree maintained at -0.085 to -0.098 MPa and the resin impregnation flow rate controlled at 2-6 cm / min. Pre-curing at room temperature for 2-4 hours and deep curing at constant temperature of 60-80℃ for 4-8 hours are carried out to construct an interlayer fiber bridging toughening system and suppress the propagation of interlayer delamination cracks under alternating bending loads.

[0016] S3. Integrated molding of sandwich structure: A gradient density foam core layer is centrally bonded between the two layers of basalt slabs of the shear web. The blade root section uses a high-density core material of 60-80 kg / m³, and the blade tip section uses a low-density core material of 30-50 kg / m³, to achieve dynamic matching of load and stiffness. An array of weight-reduction process holes with a diameter of 20-50 mm is opened in the preset area of ​​the shear web, and a reinforcing frame is integrally bonded and fixed at the edge of the hole to eliminate stress concentration at the opening. A segmented resin injection process is adopted, with an injection pressure of 0.1-0.3 MPa, a curing temperature of 50-70℃, and a curing time of 3-6 hours, to complete the overall molding of the shear web structure.

[0017] S4. Dovetail Tenon Composite Anchorage Assembly: The locking tenon at the end of the shear web is precisely aligned and embedded into the inverted trapezoidal dovetail assembly groove of the beam cap, and mechanical pre-positioning is achieved using an inverted snap-fit ​​structure; high-toughness epoxy resin is used to fill the assembly gap, and the mechanical anchorage and adhesive bonding composite load-bearing interface is formed through resin curing; during the curing stage, a gradient heating process is adopted, with the heating rate controlled at 5-10℃ / h, and constant temperature and pressure held for 2-4h, so that the shear web and the beam cap are cured into an integrated internal reinforcement component, and the interface peel strength is increased by more than 30%;

[0018] S5. Integrated mold cavity molding and packaging: The assembled and cured internal reinforcement components are precisely positioned into the blade forming mold, with the positioning deviation controlled within ±0.3mm; the blade body skin structure is continuously laid in the mold cavity to form a complete blade assembly integrating the blade root, blade leading edge and blade trailing edge; a segmented pressure curing process is adopted, with an internal pressure of 0.2~0.4MPa and a curing cycle of 8~12h, to ensure that the internal reinforcement components and the blade skin fit together without gaps or delamination defects;

[0019] S6. Detachable leading edge protective structure assembly: At the mating surface of the blade leading edge, a wedge-shaped disassembly and assembly operation groove is used to assist in precise alignment. The positioning boss on the inner side of the basalt fiber prefabricated protective strip is fully engaged and embedded into the engagement groove to achieve a gapless assembly with a gap of less than 0.1mm. The surface of the protective strip is pre-coated with a weather-resistant and erosion-resistant coating with a thickness controlled between 0.2 and 0.5mm and a hardness ≥45HD. It can resist high-frequency erosion from wind, sand and raindrops, and supports non-destructive individual disassembly and replacement.

[0020] S7. Assembly and fine post-processing: The formed blade assembly is fixed to the outside of the hub by a high-precision locking structure at the blade root, and the coaxiality error of the assembly is controlled within ≤0.5mm; the surface is polished, defects are repaired, weather-resistant gel coat is applied, and constant temperature curing is carried out in sequence. The gel coat curing temperature is 25~35℃ and the curing time is 24~48h, and the final blade product is completed.

[0021] In step S2, the basalt fiber cloth layer is a unidirectional basalt stitch-woven non-buckling fabric, which serves as the main load-bearing structure of the beam cap and mainly bears 0° axial tensile and compressive loads; the basalt stitch-woven mesh toughening layer is a low-weight sparse warp and weft mesh fabric, which is only used for interlayer bridging and toughening and does not change the mechanical properties of the main load-bearing structure; the layup process adopts a layer-by-layer degassing and step-by-step pressure stabilization process, with a vacuum stabilization time of no less than 3 minutes per layer to ensure an interlayer wetting rate of ≥99.5% and eliminate dry areas, air bubbles, and micropore defects.

[0022] In step S4, the inverted trapezoidal dovetail assembly groove is set with an inclination angle of 15° to 30°, which is perfectly matched with the locking tenon. The assembly gap is strictly controlled within 0.2 to 1 mm. The gap is formed by resin curing to form a sloping bearing structure, which transforms the traditional pure adhesive shear stress into a composite stress of compression and shear, increasing the interface shear strength by 25% to 40%. This significantly improves the fatigue resistance and peel resistance of the connection interface between the shear web and the beam cap, making it suitable for the long-term alternating flapping and oscillation load conditions of the blade. In step S6, the basalt fiber prefabricated protective strip is formed by high-temperature molding process, with a molding temperature of 120 to 150°C and a molding pressure of 3 to 6 MPa. The positioning boss and the locking groove limit locking structure enable detachable assembly without grinding and damaging the blade skin structure. The single disassembly and assembly time is ≤30 minutes, which greatly reduces the maintenance and repair costs and downtime losses after blade leading edge erosion damage.

[0023] This invention provides basalt fiber wind turbine blades and their preparation method. Compared with the prior art, it has the following advantages:

[0024] 1. This invention adopts a basalt grooved mesh interlayer toughening structure, which significantly improves the interlayer fracture toughness of the beam cap without changing the main load-bearing structure of the main beam. It effectively inhibits the propagation of interlayer cracks under alternating loads, solves the technical problems of easy delamination and poor fatigue resistance of traditional basalt blade main beams, and greatly improves the service life of the blade.

[0025] 2. The present invention adopts a dovetail tenon and mortise composite anchoring structure, which makes the web plate and the main beam cap form a composite load-bearing interface of mechanical interlocking and resin bonding. Compared with the traditional pure adhesive bonding structure, the interface shear strength is increased by 25% to 40%, and the peeling and debonding resistance is significantly enhanced. It can effectively adapt to the long-term flapping and oscillating alternating loads of the blades, and the structural connection reliability is greatly improved.

[0026] 3. The present invention adopts a gradient density foam sandwich and open-hole reinforcement structure design to achieve precise matching of blade spanwise stiffness and load. While ensuring high load-bearing stiffness at the blade root, it achieves lightweight reduction at the blade tip and reduces the overall fatigue load of the blade. At the same time, the reinforced frame completely eliminates stress concentration in the web opening, avoids local buckling and cracking, and balances lightweight and structural stability.

[0027] 4. The present invention features a detachable leading-edge basalt fiber prefabricated protective strip, which replaces the traditional single-coating protective structure. It has better erosion resistance and aging resistance, and can be disassembled and replaced without damage to the main blade structure. The disassembly and assembly time for a single maintenance is ≤30 minutes, which greatly reduces the operation and maintenance cost and downtime loss of wind turbine blades.

[0028] 5. The preparation method of this invention has fully quantifiable and controllable parameters. By precisely controlling the layup ratio, vacuum wetting degree, gradient curing process, and assembly precision, the interlayer wetting rate of the blade is guaranteed to be ≥99.5%, eliminating molding defects such as bubbles, dry areas, and micropores. The finished blade has good consistency and stable mechanical properties, making it suitable for large-scale mass production. The basalt fiber composite material is integrally molded, giving full play to the excellent properties of basalt fiber such as salt spray resistance, high temperature resistance, UV aging resistance, and corrosion resistance. It is suitable for complex and harsh wind power conditions such as offshore, sandstorm, and high-altitude cold environments, with a wider range of applicable scenarios and a significantly extended service life of the whole machine. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall three-dimensional structure of a basalt fiber wind turbine blade.

[0030] Figure 2 This is a schematic diagram of the blade assembly structure of a basalt fiber wind turbine blade.

[0031] Figure 3 Basalt fiber wind turbine blades Figure 2 Enlarged structural diagram at point A in the middle.

[0032] Figure 4 This is a schematic diagram of the three-dimensional cross-sectional structure of a basalt fiber wind turbine blade.

[0033] Figure 5 Basalt fiber wind turbine blades Figure 4 Enlarged structural diagram at point B.

[0034] Figure 6 Basalt fiber wind turbine blades Figure 5 Enlarged structural diagram at point C.

[0035] Figure 7 This is a schematic diagram of the front view of the shear web structure of a basalt fiber wind turbine blade.

[0036] Figure 8 This is a flowchart illustrating the manufacturing process of basalt fiber wind turbine blades.

[0037] The attached figures are labeled as follows:

[0038] 1. Hub; 2. Blade assembly; 201. Blade; 202. Blade root; 203. Blade leading edge; 204. Butt joint mating surface; 205. Basalt fiber prefabricated protective strip; 206. Positioning boss; 207. Engaging groove; 208. Disassembly and assembly operation slot; 3. Blade trailing edge; 4. Internal reinforcement components; 401. Beam cap; 402. Basalt fiber cloth layer; 403. Basalt stitched mesh toughening layer; 404. Shear web; 405. Foam sandwich layer; 406. Engaging tenon; 407. Inverted trapezoidal dovetail assembly slot; 408. Weight reduction process hole; 409. Reinforcing frame. Detailed Implementation

[0039] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0040] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0041] Reference Figures 1-8 Basalt fiber wind turbine blades and their manufacturing method include: a hub 1 and a blade assembly 2. The blade assembly 2 is fixedly assembled on the outside of the hub 1 and is distributed in a ring at equal intervals. The blade assembly 2 is provided with no less than three sets. An internal reinforcement component 4 is fixedly installed inside the blade assembly 2. The blade assembly 2 includes a blade 201, a blade root 202, a blade leading edge 203, a mating surface 204, a basalt fiber prefabricated protective strip 205, a positioning boss 206, a locking groove 207, and a disassembly and assembly operation groove 208. The blade 201 is provided with a blade leading edge 203 and a blade trailing edge 3 on both sides along the span.

[0042] A mating surface 204 is provided on the outer side of the leading edge 203 of the blade. The leading edge 203 of the blade is fitted with a basalt fiber prefabricated protective strip 205 through the mating surface 204, the positioning boss 206 and the locking groove 207.

[0043] The basalt fiber prefabricated protective strip 205 has an arc-shaped cross-section. A positioning boss 206 is integrally provided on the inner edge of the basalt fiber prefabricated protective strip 205. A locking groove 207 matching the positioning boss 206 is provided on the mating surface 204 of the blade leading edge 203. The positioning boss 206 is limited and locked inside the locking groove 207. A disassembly and assembly operation groove 208 is provided at the end of the basalt fiber prefabricated protective strip 205 corresponding to the positioning boss 206. The disassembly and assembly operation groove 208 is opened laterally at equal intervals and is connected to the locking groove 207.

[0044] The internal reinforcement component 4 includes a beam cap 401, a basalt fiber cloth layer 402, a basalt stitched mesh toughening layer 403, a shear web 404, a foam sandwich layer 405, a snap-fit ​​tenon 406, an inverted trapezoidal dovetail assembly groove 407, a weight reduction process hole 408, and a reinforcing frame 409. The beam cap 401 extends along the spanwise direction of the blade 201.

[0045] The beam cap 401 is set at the upper and lower ends of the inner side of the blade 201. The beam cap 401 is formed by stacking multiple layers of basalt fiber cloth 402. Every few layers of basalt fiber cloth 402, a layer of basalt stitched mesh toughening layer 403 is laid. The basalt stitched mesh toughening layer 403 is sandwiched between adjacent basalt fiber cloth layers 402.

[0046] The shear web 404 is vertically fixed between the beam caps 401. The shear web 404 and the beam caps 401 enclose the bearing cavity inside the blade 201. A foam core layer 405 is sandwiched in the middle of the shear web 404. The upper and lower ends of the shear web 404 are integrally provided with locking tenons 406. An inverted trapezoidal dovetail assembly groove 407 is opened at the docking position of the beam caps 401 and the shear web 404. The locking tenon 406 is limited and fitted into the inverted trapezoidal dovetail assembly groove 407 to form a mechanical anchoring structure.

[0047] Several weight-reduction process holes 408 are provided through the middle of the shear web 404. The weight-reduction process holes 408 are arranged equidistantly in the transverse direction. A reinforcing frame 409 is fixedly installed on the outer side of the shear web 404 and around the edge of the weight-reduction process holes 408. The reinforcing frame 409 is arranged around the edge of the weight-reduction process holes 408, and the upper and lower ends of the reinforcing frame 409 abut against the beam cap 401.

[0048] A method for preparing basalt fiber wind turbine blades includes the following steps:

[0049] S1. Multi-parameter matching prefabrication: Based on the spanwise stiffness gradient model of blade 201, core components are prefabricated in sections, forming a beam cap 401 mold with an inverted trapezoidal dovetail assembly groove 407, and a shear web 404 mold with a locking tenon 406 and an array of weight reduction process holes 408; basalt fiber prefabricated protective strips 205 are prepared using a molding process, and a gradient density foam sandwich layer 405 and a closed-loop reinforcing frame 409 are processed in conjunction. The dimensional processing accuracy of each component is controlled within ±0.05mm~±0.2mm, and the assembly gap is preset within the range of 0.2~1mm;

[0050] S2. Layered toughening gradient lay-up curing: Basalt fiber cloth 402 with a surface density of 800-1400 g / m² is laid layer by layer in the beam cap 401 mold. A layer of 80-200 g / m² basalt stitched mesh toughening layer 403 is laid every 3-8 layers of basalt fiber cloth 402 to form an alternating composite structure of main load-bearing layer and toughening transition layer. Vacuum flow technology is adopted, with the vacuum degree maintained at -0.085 to -0.098 MPa and the resin impregnation flow rate controlled at 2-6 cm / min. Pre-curing at room temperature for 2-4 hours and deep curing at constant temperature of 60-80℃ for 4-8 hours are carried out to construct an interlayer fiber bridging toughening system and suppress the propagation of interlayer delamination cracks under alternating bending loads.

[0051] S3. Integrated molding of sandwich structure: The gradient density foam core layer 405 is centrally bonded between the two layers of basalt slabs of the shear web 404. The blade root 202 section uses a high-density core material of 60-80 kg / m³, and the blade tip section uses a low-density core material of 30-50 kg / m³ to achieve dynamic matching of load and stiffness. An array of weight-reduction process holes 408 with a diameter of 20-50 mm is opened in the preset area of ​​the shear web 404, and the reinforcing frame 409 is integrally bonded and fixed at the edge of the holes to eliminate stress concentration at the openings. A segmented resin injection process is adopted, with an injection pressure of 0.1-0.3 MPa, a curing temperature of 50-70℃, and a curing time of 3-6 hours to complete the overall molding of the shear web 404 structure.

[0052] S4. Dovetail tenon composite anchoring assembly: The locking tenon 406 at the end of the shear web 404 is precisely aligned and embedded into the inverted trapezoidal dovetail assembly groove 407 of the beam cap 401, and mechanical pre-limiting is achieved by using an inverted snap-fit ​​structure; high-toughness epoxy resin is used to fill the assembly gap, and the mechanical anchoring and adhesive bonding composite load-bearing interface is formed by resin curing; during the curing stage, a gradient heating process is adopted, with the heating rate controlled at 5-10℃ / h, and constant temperature and pressure held for 2-4h, so that the shear web 404 and the beam cap 401 are cured into an integrated internal reinforcement component 4, and the interface peel strength is increased by more than 30%;

[0053] S5. Integrated mold cavity molding and encapsulation: The assembled and cured internal reinforcement component 4 is precisely positioned into the blade 201 molding mold, with the positioning deviation controlled within ±0.3mm; the main body skin structure of the blade 201 is continuously laid in the mold cavity to form a complete blade assembly 2 integrating the blade root 202, the blade leading edge 203 and the blade trailing edge 3; a segmented pressure curing process is adopted, with an internal pressure of 0.2~0.4MPa and a curing cycle of 8~12h, to ensure that the internal reinforcement component 4 and the blade 201 skin are fitted together without gaps or delamination defects;

[0054] S6. Assembly of detachable leading edge protective structure: At the mating surface 204 of the blade leading edge 203, the wedge-shaped disassembly and assembly operation groove 208 is used to assist in precise alignment, and the positioning boss 206 on the inner side of the basalt fiber prefabricated protective strip 205 is fully engaged and embedded into the engagement groove 207 to achieve a gapless assembly with a gap of less than 0.1mm; the surface of the protective strip is pre-coated with a weather-resistant and erosion-resistant coating, the coating thickness is controlled between 0.2 and 0.5mm, the hardness is ≥45HD, which can resist high-frequency erosion from wind, sand and raindrops, and supports non-destructive individual disassembly and replacement;

[0055] S7. Assembly and fine post-processing: The formed blade assembly 2 is fixed and assembled to the outside of the hub 1 through the high-precision locking structure of the blade root 202, and the coaxiality error of the assembly is controlled within ≤0.5mm; the surface is polished, defects are repaired, weather-resistant gel coat is applied, and constant temperature curing is carried out in sequence. The gel coat curing temperature is 25~35℃ and the curing time is 24~48h, and the final blade 201 finished product is completed.

[0056] In step S2, the basalt fiber cloth layer 402 is a unidirectional basalt stitch-woven non-buckling fabric, which serves as the main load-bearing structure of the beam cap 401, mainly bearing 0° axial tensile and compressive loads; the basalt stitch-woven mesh toughening layer 403 is a low-weight sparse warp and weft mesh fabric, which is only used for interlayer bridging and toughening, and does not change the mechanical properties of the main load-bearing structure; the layup process adopts a layer-by-layer degassing and step-by-step pressure stabilization process, with a vacuum stabilization time of no less than 3 minutes per layer, ensuring an interlayer wetting rate of ≥99.5%, and eliminating dry areas, air bubbles, and micropore defects.

[0057] In step S4, the inverted trapezoidal dovetail assembly groove 407 has an inclination angle of 15° to 30°, which is perfectly matched with the locking tenon 406. The assembly gap is strictly controlled within 0.2 to 1 mm. The gap is formed by resin curing to form a sloping bearing structure, which transforms the traditional pure adhesive shear stress into a composite stress of compression and shear, increasing the interface shear strength by 25% to 40%. This significantly improves the fatigue resistance and peel resistance of the connection interface between the shear web 404 and the beam cap 401, making it suitable for the long-term alternating flapping and oscillating load conditions of the blade 201. In step S6, the basalt fiber prefabricated protective strip 205 adopts a high-temperature molding process with a molding temperature of 120 to 150°C and a molding pressure of 3 to 6 MPa. The positioning boss 206 and the locking groove 207 limit the locking structure to achieve detachable assembly without grinding and damaging the main skin structure of the blade 201. The single disassembly and assembly time is ≤30 minutes, which greatly reduces the maintenance and repair costs and downtime losses after the blade leading edge 203 is eroded.

[0058] During use, a basalt stitched mesh toughening layer 403 is laid intermittently between the multiple unidirectional basalt fiber cloth layers 402 of the beam cap 401. After being impregnated with resin, the low-weight mesh fabric forms a dense fiber bridging structure between the layers, which can effectively lock the interlayer microcracks and prevent the cracks from extending under alternating bending loads. This solves the defects of insufficient interlayer toughness and easy delamination and cracking in traditional pure cloth layer composite structures, and greatly improves the fatigue resistance and structural stability of the beam cap 401.

[0059] The locking tenon 406 at the end of the shear web 404 and the inverted trapezoidal dovetail assembly groove 407 of the beam cap 401 form an inverted mechanical anchoring structure. Combined with high-toughness resin that is filled and cured in the gap, a composite load-bearing system of mechanical fitting and resin bonding is constructed. This system transforms the pure shear load of traditional single bonding into a composite load of inclined plane compression and shear, effectively dispersing interface stress, avoiding interface debonding and adhesive layer cracking under alternating loads, and improving the connection reliability between the web and the main beam.

[0060] The internal foam core layer 405 of the shear web 404 adopts a gradient density arrangement of high density at the blade root 202 and low density at the blade tip, matching the spanwise load distribution characteristics of the blade 201. The high stress area at the blade root 202 ensures structural stiffness and load-bearing capacity, while the low stress area at the blade tip achieves lightweighting and weight reduction, reducing the overall inertial load and oscillation fatigue damage of the blade 201. At the same time, the array-type weight reduction process holes 408 of the web, together with the hole-edge closed-loop reinforcing frame 409, completely eliminate the stress concentration of the openings while achieving weight reduction, avoiding local buckling failure of the web.

[0061] The leading edge 203 of the blade achieves rapid engagement and assembly of the basalt fiber prefabricated protective strip 205 through the positioning boss 206 and the engaging groove 207. The protective strip is independently formed and has its own weather-resistant and erosion-resistant coating, which can resist high-frequency erosion and wear from wind, sand and raindrops. When the protective strip is damaged and fails, it can be disassembled and replaced without damage through the disassembly and assembly operation slot 208, without the need to grind or repair the main structure of the blade 201, which greatly simplifies the operation and maintenance process and reduces maintenance costs. By precisely quantifying the layup ratio, vacuum impregnation parameters, gradient curing temperature and pressure, and assembly gap accuracy, the blade 201 components are integrated and formed with high precision. The forming defects are controlled throughout the process to ensure high interlayer impregnation rate and gapless interface bonding, thereby improving the overall structural consistency and mechanical performance stability of the blade 201 and adapting to the long-term service requirements under complex working conditions.

[0062] Therefore, although the invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are also within the scope of the foregoing disclosure, and it should be understood that in some cases, certain features of the invention may be adopted without departing from the scope and spirit of the invention and without corresponding use of other features. Thus, many modifications can be made to adapt a particular environment or material to the essential scope and spirit of the invention. The invention is not intended to be limited to the specific terminology used in the following claims and / or the specific embodiments disclosed as the best mode for carrying out the invention, but the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Therefore, the scope of the invention will be defined only by the appended claims.

Claims

1. A basalt fiber wind turbine blade, characterized in that, include: The hub (1) and blade assembly (2) are fixedly assembled on the outside of the hub (1) and distributed in a ring at equal intervals. The blade assembly (2) is provided with no less than three sets. An internal reinforcement assembly (4) is fixedly installed inside the blade assembly (2). The blade assembly (2) includes a blade (201), a blade root (202), a blade leading edge (203), a mating surface (204), a basalt fiber prefabricated protective strip (205), a positioning boss (206), a locking groove (207), and a disassembly and assembly operation groove (208). The blade (201) is provided with a blade leading edge (203) and a blade trailing edge (3) on both sides along the span.

2. The basalt fiber wind turbine blade according to claim 1, characterized in that, The blade leading edge (203) is provided with a mating surface (204) on the outside. The blade leading edge (203) is fitted with a basalt fiber prefabricated protective strip (205) through the mating surface (204), the positioning boss (206) and the engaging groove (207).

3. The basalt fiber wind turbine blade according to claim 2, characterized in that, The basalt fiber prefabricated protective strip (205) has an arc-shaped cross section. A positioning boss (206) is integrally provided on the inner edge of the basalt fiber prefabricated protective strip (205). A locking groove (207) matching the positioning boss (206) is opened on the mating surface (204) of the leading edge (203) of the blade. The positioning boss (206) is limited and locked inside the locking groove (207). A disassembly and assembly operation groove (208) is opened at the end of the basalt fiber prefabricated protective strip (205) corresponding to the positioning boss (206). The disassembly and assembly operation groove (208) is opened horizontally at equal intervals. The disassembly and assembly operation groove (208) is connected to the locking groove (207).

4. The basalt fiber wind turbine blade according to claim 1, characterized in that, The internal reinforcement component (4) includes a beam cap (401), a basalt fiber cloth layer (402), a basalt stitched mesh toughening layer (403), a shear web (404), a foam sandwich layer (405), a snap-fit ​​tenon (406), an inverted trapezoidal dovetail assembly groove (407), a weight reduction process hole (408), and a reinforcing frame (409). The beam cap (401) extends along the spanwise direction of the blade (201).

5. The basalt fiber wind turbine blade according to claim 4, characterized in that, The beam cap (401) is located at the upper and lower ends of the inner side of the blade (201). The beam cap (401) is formed by stacking multiple layers of basalt fiber cloth (402). A layer of basalt stitched mesh toughening layer (403) is laid every few layers of basalt fiber cloth (402). The basalt stitched mesh toughening layer (403) is sandwiched between adjacent basalt fiber cloth layers (402).

6. The basalt fiber wind turbine blade according to claim 5, characterized in that, The shear web (404) is vertically fixed between the beam cap (401). The shear web (404) and the beam cap (401) enclose the blade to form an internal bearing cavity. A foam core layer (405) is sandwiched in the middle of the shear web (404). The upper and lower ends of the shear web (404) are integrally provided with a locking tenon (406). An inverted trapezoidal dovetail assembly groove (407) is opened at the docking position of the beam cap (401) and the shear web (404). The locking tenon (406) is limited and fitted into the inverted trapezoidal dovetail assembly groove (407) to form a mechanical anchoring structure.

7. The basalt fiber wind turbine blade according to claim 6, characterized in that, The shear web (404) has several weight reduction process holes (408) through the middle of the plate body. The weight reduction process holes (408) are arranged equidistantly in the transverse direction. A reinforcing frame (409) is fixedly installed on the outer side of the shear web (404) and the edge of the weight reduction process holes (408). The reinforcing frame (409) is arranged around the edge of the weight reduction process holes (408), and the upper and lower ends of the reinforcing frame (409) abut against the beam cap (401).

8. A method for preparing basalt fiber wind turbine blades, applied to the basalt fiber wind turbine blades described in any one of claims 1-7, characterized in that: Includes the following steps: S1. Multi-parameter matching prefabrication: Based on the spanwise stiffness gradient model of the blade (201), the core components are prefabricated in sections, forming a beam cap (401) mold with an inverted trapezoidal dovetail assembly groove (407), and a shear web (404) mold with a snap-fit ​​tenon (406) and an array of weight reduction process holes (408); basalt fiber prefabricated protective strips (205) are prepared using a molding process, and a gradient density foam sandwich layer (405) and a closed-loop reinforcing frame (409) are processed in conjunction. The dimensional processing accuracy of each component is controlled within ±0.05mm to ±0.2mm, and the assembly gap is preset within the range of 0.2 to 1mm. S2. Layered toughening gradient lay-up curing: Basalt fiber cloth (402) with a surface density of 800-1400 g / m² is laid layer by layer in the beam cap (401) mold. A layer of 80-200 g / m² basalt stitched mesh toughening layer (403) is laid every 3-8 layers of basalt fiber cloth (402) to form an alternating composite structure of main load-bearing layer and toughening transition layer. Vacuum flow technology is adopted, the vacuum degree is maintained at -0.085--0.098 MPa, the resin impregnation flow rate is controlled at 2-6 cm / min, room temperature pre-curing for 2-4 h, constant temperature 60-80℃ deep curing for 4-8 h, to build an interlayer fiber bridging toughening system and suppress the propagation of interlayer delamination cracks under alternating bending load. S3. Integrated molding of sandwich structure: The gradient density foam core layer (405) is centrally attached between the double-layer basalt plate of the shear web (404). The blade root (202) section uses a high-density core material of 60-80 kg / m³, and the blade tip section uses a low-density core material of 30-50 kg / m³ to achieve dynamic matching of load and stiffness. An array of weight reduction process holes (408) with a diameter of 20-50 mm is opened in the preset area of ​​the shear web (404), and the reinforcing frame (409) is integrally bonded and fixed at the edge of the hole to eliminate stress concentration of the opening. The segmented resin injection process was adopted, with an injection pressure of 0.1-0.3 MPa, a curing temperature of 50-70℃, and a curing time of 3-6 hours, to complete the overall structural molding of the shear web (404). S4. Dovetail tenon composite anchoring assembly: The locking tenon (406) at the end of the shear web (404) is precisely aligned and embedded into the inverted trapezoidal dovetail assembly groove (407) of the beam cap (401), and the mechanical pre-limiting is achieved by using the inverted snap structure; the assembly gap is filled with high toughness epoxy resin, and the mechanical anchoring and adhesive bonding composite bearing interface is formed by resin curing; the curing stage adopts a gradient heating process, the heating rate is controlled at 5~10℃ / h, and the constant temperature and pressure are maintained for 2~4h, so that the shear web (404) and the beam cap (401) are cured into an integrated internal reinforcement component (4), and the interface peel strength is increased by more than 30%; S5. Integrated mold cavity molding and packaging: The assembled and cured internal reinforcement component (4) is precisely positioned into the blade forming mold, and the positioning deviation is controlled within ±0.3mm; the blade (201) main skin structure is continuously laid in the mold cavity to form a complete blade assembly (2) integrating the blade root (202), the blade leading edge (203) and the blade trailing edge (3); the segmented pressure curing process is adopted, with an internal pressure of 0.2~0.4MPa and a curing cycle of 8~12h to ensure that the internal reinforcement component (4) and the blade (201) skin are bonded together without gaps and without delamination defects; S6. Assembly of detachable protective structure at the leading edge: At the mating surface (204) of the blade leading edge (203), the wedge-shaped disassembly and assembly operation groove (208) is used to assist in precise alignment. The positioning boss (206) on the inner side of the basalt fiber prefabricated protective strip (205) is fully engaged and embedded into the engagement groove (207) to achieve gapless assembly with a gap of less than 0.1mm. The surface of the protective strip is pre-coated with a weather-resistant and erosion-resistant coating. The coating thickness is controlled at 0.2-0.5mm and the hardness is ≥45HD. It can resist high-frequency erosion from wind, sand and raindrops, and supports non-destructive individual disassembly and replacement. S7. Assembly and fine post-processing: The formed blade assembly (2) is fixed and assembled on the outside of the hub (1) through the high-precision locking structure of the blade root (202). The coaxiality error of the assembly is controlled within ≤0.5mm. Surface grinding, defect repair, weather-resistant gel coat coating, and constant temperature curing are carried out in sequence. The gel coat curing temperature is 25~35℃ and the curing time is 24~48h. Finally, the blade (201) finished product is completed.

9. The method for preparing basalt fiber wind turbine blades according to claim 8, characterized in that, In step S2, the basalt fiber cloth layer (402) is a unidirectional basalt stitch-woven non-buckling fabric, which serves as the main load-bearing structure of the beam cap (401) and mainly bears 0° axial tensile and compressive loads; the basalt stitch-woven mesh toughening layer (403) is a low-weight sparse warp and weft mesh fabric, which is only used for interlayer bridging and toughening and does not change the mechanical properties of the main load-bearing structure; the layup process adopts a layer-by-layer degassing and step-by-step pressure stabilization process, with a vacuum stabilization time of no less than 3 minutes per layer to ensure an interlayer wetting rate of ≥99.5% and eliminate dry areas, bubbles, and micropore defects.

10. The method for preparing basalt fiber wind turbine blades according to claim 8, characterized in that, In step S4, the inverted trapezoidal dovetail assembly groove (407) is set with an inclination angle of 15° to 30°, which is perfectly matched with the locking tenon (406), and the assembly gap is strictly controlled within 0.2 to 1 mm; the inclined bearing structure is formed by the curing of the gap resin, which transforms the traditional pure adhesive shear stress into a composite stress of compression and shear, and the interface shear strength is increased by 25% to 40%, which significantly improves the fatigue resistance and peel resistance of the connection interface between the shear web (404) and the beam cap (401), and is suitable for the long-term alternating of the blade (201). In the swing and oscillation load conditions, in step S6, the basalt fiber prefabricated protective strip (205) adopts a high-temperature molding process with a molding temperature of 120-150℃ and a molding pressure of 3-6MPa. The detachable assembly is achieved through the limiting engagement structure of the positioning boss (206) and the engaging groove (207), without the need to grind and damage the main skin structure of the blade (201). The single disassembly and assembly time is ≤30min, which greatly reduces the maintenance and repair costs and downtime losses after the blade leading edge (203) is eroded.

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