A wind turbine blade of basalt carbon fibre composite variable density material combination

Abstract

A wind turbine blade made of basalt carbon fiber composite variable density material combination, including at least one blade unit assembled along the length direction of the blade, the density gradient increases from the blade tip to the blade root through the gradient distribution of material density and / or the gradient distribution of hollow structure, and adjacent blade units are detachably connected through non-threaded connection structure. The modular design of the blade solves the problem of land transportation of oversized blades, and the non-threaded connection (hand disassembly) improves the efficiency of on-site installation and eliminates the risk of thread loosening. Lightweight blade tip reduces starting torque, facilitates handling and assembly, and improves wind speed and power generation efficiency.

Description

Technical Field

[0001] This invention belongs to the field of wind power generation, and specifically relates to a variable density wind turbine blade, especially a wind turbine blade composed of basalt carbon fiber composite variable density material. Background Technology

[0002] Current mainstream wind turbine blades are long, and land transportation is limited by bridges and culverts (width limit 4.5 meters) and curve radii (minimum turning radius ≥ 50 meters), necessitating the disassembly of integral blades into multiple segments. Existing technologies disclose segmented wind turbine blade connections relying on threaded fasteners or locking mechanisms, which carries certain thread-related risks. Long-term vibration can cause bolts to loosen, requiring high-altitude maintenance and posing significant safety hazards. Furthermore, current solutions only achieve a gradual change in blade weight from root to tip through the shape and size of the blade; they lack further detailed weight reduction design. For applications with light winds, the excessively high tip moment of inertia results in poor start-up capability. Additionally, the generally heavy blade weight increases the difficulty and cost of handling and assembly. Summary of the Invention

[0003] To address the aforementioned problems, this invention discloses a wind turbine blade composed of a basalt carbon fiber composite variable density material, comprising at least one blade unit assembled along the blade's length direction. The density gradient increases from the blade tip to the blade root through a material density gradient distribution and / or a blind hole groove structure gradient distribution. Adjacent blade units are detachably connected via a non-threaded connection structure. This structure includes:

[0004] a. Radial limiting unit: realizes circumferential constraint between blade units;

[0005] b. Axial anti-detachment unit: realizes axial locking between blade units.

[0006] Furthermore, the density gradient is achieved through a combination of materials:

[0007] a. Blade tip unit: carbon fiber / resin composite material or basalt fiber / resin composite material, density 1.4-1.6 g / cm³ 3 ;

[0008] b. Leaf unit: carbon fiber / resin composite or basalt fiber / resin composite, density 1.6-1.8 g / cm³ 3 ;

[0009] c. Leaf root unit: carbon fiber / resin composite material or basalt fiber / resin composite material, density 1.8-2.0 g / cm³ 3 .

[0010] Furthermore, the density gradient is achieved through a blind-hole groove structure:

[0011] a. A blind hole is provided on the leeward side of the blade tip unit, and the depth of the blind hole accounts for 60% of the cross-sectional thickness;

[0012] b. The depth of the blind hole in the blade unit accounts for 40% of the cross-sectional thickness;

[0013] c. The leaf root unit has no blind holes.

[0014] Furthermore, the density gradient is achieved through the difference in the number of blind hole grooves: the number of blind hole grooves in the leaf root unit, leaf middle unit, and leaf tip unit increases sequentially.

[0015] Furthermore, the radial limiting unit is an axial insertion assembly, comprising:

[0016] a. A stepped shaft located in the first blade unit, the outer diameter of which varies from D1 to D2 to D1, and D2 > D1; b. A matching shaft hole located in the second blade unit;

[0017] c. The axial anti-detachment unit is a T-shaped fixing pin that passes through the stepped shaft and the blade unit. The T-shaped fixing pin passes through the stepped shaft and two adjacent blade units, and its end is locked by an open retaining ring. Further, the radial limiting unit is a dovetail slide rail assembly, including:

[0018] a. Dovetail groove and limiting block provided in the first blade unit;

[0019] b. A matching slider is provided in the second blade unit;

[0020] c. The axial anti-disengagement unit is a spring-loaded latch, which extends automatically via a spring;

[0021] d. The slider is confined within the lock tongue groove by the limiting block and the locking tongue. e. The lock tongue push rod is exposed on the surface of the blade unit, with an exposed length of not less than 5mm.

[0022] Furthermore, the inner wall of the blind hole is fitted with a micro-perforated sound-absorbing membrane with a pore diameter of 0.1-0.5 mm.

[0023] Furthermore, the spring latch and / or the surface of the spring are covered with an Al2O3-ZrO2 ceramic anti-rust coating with a thickness of 50-100μm.

[0024] Furthermore, the spring latch includes an exposed latch push rod, which can drive the latch to move in a straight line.

[0025] The present invention adopts the above-mentioned solution, and its beneficial effects are as follows: Through the above solution, a modular blade design can be achieved. The modular blade unit solves the problem of transporting ultra-large blades by land. Non-threaded connections (manual disassembly and assembly) improve on-site installation efficiency and eliminate the risk of loose threads. The lightweight blade tip design reduces starting torque, increases wind speed power generation, and is more conducive to transportation and assembly, improving power generation efficiency. High-density blade roots enhance bending stiffness and extend fatigue life. Simultaneously, the sound-absorbing membrane in the blind hole groove reduces aerodynamic noise. Standardized connectors support partial replacement, reducing maintenance costs. The use of environmentally friendly materials such as basalt fiber significantly reduces the environmental impact of the blade throughout its entire life cycle, aligning with the development trend of green energy equipment. Attached Figure Description

[0026] Figure 1 This is an overall appearance drawing of the wind turbine generator described in this application;

[0027] Figure 2 This is an exploded view of the first embodiment of this application;

[0028] Figure 3 This is a partial enlarged view of the exploded portion of the first embodiment of this application;

[0029] Figure 4 This is an assembly diagram of a single blade unit according to the first embodiment of this application;

[0030] Figure 5 This is an exploded view of a single blade unit according to the first embodiment of this application;

[0031] Figure 6 This is a perspective view of the stepped shaft of the first embodiment of this application;

[0032] Figure 7 This is a perspective view of the T-shaped fixing pin according to the first embodiment of this application;

[0033] Figure 8 This is a three-dimensional view of the windward side of the first embodiment of this application;

[0034] Figure 9 This is a partial enlarged view of the windward side of the first embodiment of this application;

[0035] Figure 10 This is a schematic diagram of an explosion on the windward side of the first embodiment of this application;

[0036] Figure 11 This is a partial enlarged view of the spring latch of the first embodiment of this application;

[0037] Figure 12 This is yet another exploded perspective view of the first embodiment of this application;

[0038] Figure 13This is a partial enlarged view of the slider according to the first embodiment of this application;

[0039] Figure 14 This is a schematic diagram of the appearance of the spring latch according to the first embodiment of this application;

[0040] Figure 15 A schematic diagram of the slider and groove assembly corresponding to one of the blade units in the first embodiment of this application is shown.

[0041] Figure 16 This is a partially enlarged view of the slider and groove assembly according to the first embodiment of this application;

[0042] Figure 17 This is a schematic diagram of the material density partitioning of the blade unit according to the second embodiment of this application;

[0043] Figure 18 This is a schematic diagram of the blind hole groove partitioning of the blade unit according to the third embodiment of this application;

[0044] Figure 19 This is a cross-sectional view of the blind hole groove in the leaf middle area according to the third embodiment of this application;

[0045] Figure 20 This is a cross-sectional view of the blind hole groove in the blade tip region according to the third embodiment of this application;

[0046] Figure 21 This is a schematic diagram of the installation of the sound-absorbing membrane in the hollow area according to the third embodiment of this application;

[0047] In the diagram: 1-First blade unit; 2-Second blade unit; 3-Third blade unit; 4-Stepped shaft; 131-Shaft hole; 5-T-shaped fixing pin; 6-Open retaining ring; 7-Blade unit; 8-Blade unit; 11-Outer skin; 12-Blade skeleton; 13-Round tube; 41-Stepped shaft section 1; 42-Stepped shaft section 2; 43-Stepped shaft section 3; 44-Stepped shaft side hole; 51-Fixing pin flange; 52-Fixing pin shaft; 53-Annular groove; 81-Swallow Tail groove; 82-Limit block; 83-Spring locking tongue; 100-Blade root unit; 101-Blade root unit; 111-Through hole; 131-Inner hole of round tube; 132-Side hole of round tube; 200-Middle blade unit; 201-Middle blade unit; 300-Blade tip unit; 301-Blade tip unit; 831-Locking tongue; 832-Locking tongue push rod; 833-Locking tongue spring; 834-Locking tongue seat; 2011-Blind hole groove; 3011-Blind hole groove; 3012-Sound absorbing membrane. Detailed Implementation

[0048] The present invention will now be described in detail with reference to the accompanying drawings.

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0050] like Figure 1 As shown, a typical wind turbine blade includes a tip region and a root region. The tip region is located at the distal end, and the root region is located near the center of the blade's axis of rotation. Figure 2 , 3 As shown, a wind turbine blade includes a first blade unit 1, a second blade unit 2, and a third blade unit 3 assembled along the blade's length. Adjacent blade units are detachably connected via a non-threaded connection structure, which includes:

[0051] a. Radial limiting unit: realizes circumferential constraint between blade units;

[0052] b. Axial anti-detachment unit: realizes axial locking between blade units.

[0053] The radial limiting unit is an axial insertion assembly, including: a stepped shaft 4 provided in the first blade unit, the outer diameter of which varies from D1 to D2 to D1, and D2 > D1; a matching shaft hole 131 provided in the second blade unit; the axial anti-detachment unit is a T-shaped fixing pin 5 that passes through the stepped shaft 4 and the blade unit, the T-shaped fixing pin 5 passes through the stepped shaft 4 and two adjacent blade units, and the end is locked by an open retaining ring 6.

[0054] like Figure 4 , 5 As shown, the schematic diagram of the appearance and internal structure of the single blade unit 1 includes an outer skin 11, which is made of steel and includes multiple through holes 111. The interior includes multiple blade skeletons 12 and at least two circular tubes 13 connecting the blade skeletons. The circular tubes 13 include a circular tube inner hole 131 and multiple circular tube side holes 132.

[0055] like Figure 6 The diagram further shows a detailed structural diagram of the stepped shaft 4, including a first stepped shaft section 41, a second stepped shaft section 42, and a third stepped shaft section 43. The first stepped shaft section 41 and the third stepped shaft section 43 have the same outer diameter, D1, while the outer diameter of the stepped shaft 42 is D2, where D2 > D1. The stepped shaft 4 also includes multiple stepped shaft side holes 44.

[0056] like Figure 7 As shown, the T-shaped fixing pin 5 includes a fixing pin flange 51 and a fixing pin shaft 52. The outer diameter of the fixing pin flange is larger than the outer diameter of the fixing pin shaft. The end of the fixing pin shaft away from the fixing pin flange includes an annular groove 53. The groove 53 is used to install an elastic opening retaining ring 6.

[0057] Combination Figure 3 , 6 7. Insert the stepped shaft 4 into the corresponding inner hole 131 of the inner tube 13 of the blade unit. Then, insert the T-shaped fixing pin 5 from the side, passing through the through hole 111, the side hole 132 of the tube, and the side hole 44 of the stepped shaft on the outer skin 11 of the blade in sequence, until the groove 53 on the T-shaped fixing pin 5 is exposed from the other side surface of the blade skin. Then, install the elastic open retaining ring 6. The combined installation of the T-shaped fixing pin and the open retaining ring can replace the traditional screw thread installation. During the rotation of the wind blade, even vibration can greatly reduce the failure of the assembly structure. If materials with better weather resistance and corrosion resistance are selected for the T-shaped fixing pin 5 and the open retaining ring 6, the safe service life of the blade can be improved.

[0058] like Figure 8 , 9 As shown, another embodiment of a wind turbine blade includes blade unit 7 and blade unit 8 that are assembled and docked to each other. The locking tongue push rod 832 in the blade unit 8 corresponding to the spring locking tongue is exposed on the surface of the blade unit, with an exposed length of not less than 5 mm, and supports manual sliding unlocking to facilitate the assembly and disassembly of the two independent blade units.

[0059] like Figure 10 , 11 As shown in Figures 12, 13, 14, and 15, the blade unit 7 and blade unit 8 are shown in exploded views and partial enlarged views from two angles. The blade unit 8 includes a dovetail groove 81 and a limiting block 82. A spring latch 83 is installed above the dovetail groove 81. The spring latch 83 includes a latch 831, a latch push rod 832 that slides integrally with the latch 831, an internally pushing latch spring 833, and a latch seat 834. The latch 831 extends automatically under the push of the latch spring 833. When the slider 71 on the blade unit 7 is inserted into the groove 81 on the latch blade unit 8, the slider 71 is confined within the latch groove 81 by the limiting block 82 and the latch 831. The surface of the spring latch and / or the spring is covered with an Al2O3-ZrO2 ceramic anti-rust coating with a thickness of 50-100 μm.

[0060] like Figure 17 Another blade embodiment is shown, where the blade unit is divided into three large regions: the tip unit 300, the middle unit 200, and the root unit 100. These three units are independent blade units fixedly connected together through assembly, or the three units themselves form a single blade divided into three regions. The density gradient from the tip to the root is achieved through a material density gradient distribution. This density gradient is achieved through material combinations, specifically including:

[0061] a. Blade tip unit: carbon fiber / resin composite material or basalt fiber / resin composite material, density 1.4-1.6 g / cm³ 3 ;

[0062] b. Leaf unit: carbon fiber / resin composite or basalt fiber / resin composite, density 1.6-1.8 g / cm³ 3 ;

[0063] c. Leaf root unit: carbon fiber / resin composite material or basalt fiber / resin composite material, density 1.8-2.0 g / cm³ 3 .

[0064] like Figure 18 , 19 Another blade embodiment shown in Figure 20, the blade being similar to Figure 17 The embodiment is divided into three regions: the leaf tip unit 301, the leaf middle unit 201, and the leaf root unit 101. The leaf middle unit 201 includes blind hole grooves 2011, and the leaf tip unit 301 also includes blind hole grooves 3011. The density gradient is achieved through the difference in the number of blind hole grooves: the number of blind hole grooves in the leaf root unit 101, leaf middle unit 201, and leaf tip unit 301 increases sequentially. Alternatively, the density gradient is achieved through a blind hole groove structure.

[0065] a. A blind hole is provided on the leeward side of the blade tip unit, and the depth of the blind hole groove accounts for 60% of the cross-sectional thickness;

[0066] b. The depth of the blind hole groove in the blade unit accounts for 40% of the cross-sectional thickness;

[0067] c. The leaf root unit has no blind hole groove.

[0068] like Figure 21 As shown, the inner wall of the blind hole is fitted with a micro-perforated sound-absorbing membrane 3012 with a pore diameter of 0.1-0.5 mm. The sound-absorbing membrane can better reduce aerodynamic noise.

[0069] In the figures of this invention, the same or similar reference numerals correspond to the same or similar components. In the description of this invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figure, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the figures are only for illustrative purposes and should not be construed as limiting this invention. For those skilled in the art, the specific meaning of the above-mentioned terms can be understood according to the specific circumstances.

[0070] It should be noted that when a component is referred to as being "connected" to another component, it can be directly connected to the other component or there may be an intermediate component; when a component is referred to as being "fixed" to another component, it can be directly fixed to the other component or there may be an intermediate component, which can be done by effective means such as bonding, welding, riveting, bolting, etc., which will not be listed in this application; when a component is referred to as being "movable" to another component, it can be done by rotation or sliding.

[0071] This application is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A wind turbine blade, characterized in that: The blade comprises at least one blade unit assembled along its length, with a density gradient increasing from the blade tip to the blade root. Adjacent blade units are detachably connected via a non-threaded connection structure, which allows for manual assembly and disassembly. This non-threaded connection structure includes: a. a radial limiting unit: providing circumferential constraint between blade units; b. an axial anti-detachment unit: providing axial locking between blade units. The increasing density gradient is achieved through a material density gradient distribution and a perforated structure gradient distribution. The leaf tip unit uses basalt fiber / resin composite material with a density of 1.4-1.6 g / cm³, the leaf middle unit uses basalt fiber / resin composite material with a density of 1.6-1.8 g / cm³, and the leaf root unit uses basalt fiber / resin composite material with a density of 1.8-2.0 g / cm³. The density gradient is achieved through a blind hole groove structure. The tip unit has blind holes on the leeward side, with the depth of the blind holes accounting for 60% of the cross-sectional thickness. The middle unit has blind holes with a depth of 40% of the cross-sectional thickness. The root unit has no blind holes. Alternatively, the density gradient is achieved through the difference in the number of blind hole grooves: the number of blind hole grooves in the root unit, middle unit, and tip unit increases sequentially. The radial limiting unit is a dovetail slide rail assembly, which includes: a. a dovetail groove and limiting block provided in the first blade unit; b. a matching slider provided in the second blade unit; c. the axial anti-disengagement unit is a spring latch, which extends automatically by a spring; d. the slider is limited within the latch groove by the limiting block and the latch; e. the latch push rod in the spring latch is exposed on the surface of the blade unit, with an exposed length of not less than 5mm.

2. A wind turbine blade according to claim 1, characterized in that: The inner wall of the blind hole is fitted with a micro-perforated sound-absorbing membrane with a pore size of 0.1-0.5mm.

3. A wind turbine blade according to claim 1, characterized in that: The spring latch is covered with an Al2O3-ZrO2 ceramic anti-rust coating with a thickness of 50-100μm.

4. A wind turbine blade according to claim 1, characterized in that: The surface of the spring is covered with an Al2O3-ZrO2 ceramic anti-rust coating with a thickness of 50-100μm.

5. The wind turbine blade according to claim 1, characterized in that: The spring latch includes an exposed latch push rod, which drives the latch to move in a straight line.

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