Fan blade capable of changing pitch in segmented mode

Abstract

The invention relates to the technical field of fan blades, and discloses a sectionalized variable-pitch fan blade which comprises a blade body, a connecting assembly and a variable-pitch assembly. The blade comprises a plurality of blade sections, and the blade section located at the root is connected to the hub. The connecting assembly comprises a plurality of connecting pieces, and one connecting piece is arranged in each blade section; the variable-pitch assembly comprises a plurality of variable-pitch mechanisms, one variable-pitch mechanism is arranged on the hub, the driving end of the variable-pitch mechanism is connected with the blade section located at the root, the other variable-pitch mechanisms are arranged at the joint of every two adjacent blade sections, the connecting piece in one blade section, close to the hub, of every two adjacent blade sections is provided with one variable-pitch mechanism, and the connecting piece in the other blade section is provided with one variable-pitch mechanism. According to the wind driven generator, the blades of the wind driven generator are segmented, each blade section can be controlled by the variable pitch mechanism to carry out independent variable pitch, the whole blade of the wind driven generator is adjusted to a proper power generation angle, and the power generation efficiency of the wind driven generator is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine blades, and in particular to a wind turbine blade capable of variable pitch in sections. Background Art

[0002] As a clean and renewable energy source, wind energy has received extensive attention and application in recent years. Wind power generation is a technology that uses wind power to drive the blades of wind turbines to rotate, thereby driving generators to generate electricity. In wind turbines, the design of the blades is crucial to the performance of the wind turbine. The length and angle of the blades directly affect the power output, efficiency and life of the wind turbine.

[0003] The length of the wind turbine blade is closely related to the power output of the wind turbine. Generally speaking, longer blades can capture more wind energy, thereby improving the power generation efficiency of the wind turbine. Blade pitch control refers to adjusting the angle between the wind turbine blade and the wind through the pitch mechanism, thereby changing the speed and power output of the wind turbine to adapt to different wind speed conditions and maximize the power generation efficiency of the wind turbine. Blade pitch control is crucial to the stability and efficiency of wind turbines, especially when the wind speed is low or high, it can keep the wind turbine in the optimal operating state. The conventional pitch mechanism is set at the root of the wind turbine blade. However, as the length of the wind turbine blade increases, if the root pitch method is also adopted for the super-long wind turbine blades exceeding 100 meters, the pitch mechanism needs to output a large torque and is easy to be damaged. For this reason, in the prior art, the super-long wind turbine blades are divided into two sections, one is a fixed pitch section, and the other end is a variable pitch section. The pitch mechanism is set in the fixed pitch section to adjust the angle of the variable pitch section. Although this method reduces the output torque of the pitch mechanism, it can only achieve partial pitch adjustment of the wind turbine blades. The pitch adjustment effect is poor and will affect the power generation efficiency of the wind turbine. Summary of the invention

[0004] In view of this, the present invention provides a wind turbine blade with segmented pitch adjustment to solve the problem that the pitch adjustment technology can only achieve partial pitch adjustment of the wind turbine blade, the pitch adjustment effect is poor, and the power generation efficiency of the wind turbine is affected.

[0005] In a first aspect, the present invention provides a wind turbine blade capable of variable pitch in sections, comprising:

[0006] a blade, the blade comprising a plurality of blade segments, and one of the blade segments located at a root is connected to a hub;

[0007] A connecting assembly, the connecting assembly comprising a plurality of connecting pieces, and one connecting piece is disposed in each of the blade segments;

[0008] A pitch assembly, the pitch assembly comprising a plurality of pitch mechanisms, wherein one group of pitch mechanisms is arranged at the hub, and a driving end thereof is connected to the blade segment located at the root, and the remaining pitch mechanisms are arranged at the connection between two adjacent blade segments, and one group of pitch mechanisms is arranged on the connecting piece in one of the blade segments close to the hub, and the driving end of the pitch mechanism is connected to the connecting piece in one of the blade segments far away from the hub.

[0009] Beneficial Effects

[0010] The super-long blades are divided into multiple blade segments, and the segmented independent pitch design is adopted, so that each blade segment can adjust the pitch angle individually. This segmented pitch design effectively reduces the torque demand of a single pitch mechanism, reduces the load pressure of the pitch mechanism, and extends the service life of the pitch mechanism. In addition, the pitch adjustment of each blade segment is more flexible, and the pitch angle of each blade segment can be adjusted according to different wind speed conditions to optimize the power generation efficiency of the wind turbine.

[0011] In an optional embodiment, the outer diameters of the plurality of connecting members in the blade decrease gradually from the root of the blade to the tip of the blade.

[0012] Beneficial Effects

[0013] The outer diameter of multiple connecting parts in the blade gradually decreases from the root to the tip, optimizing the strength distribution of the blade structure. The decreasing outer diameter design reduces the weight and inertia of the blade tip, improves the dynamic response ability of the blade, and enhances the stability of the fan operation.

[0014] In an optional embodiment, one end of the connecting member in one of the two adjacent blade segments away from the hub extends into the connecting member in the other blade segment and is connected to the driving end of the pitch mechanism.

[0015] Beneficial Effects

[0016] Two adjacent blade segments are connected by a connecting piece inside the blade segment. This blade segment connection method improves the overall strength of the blade. The connecting piece is connected to the drive end of the pitch mechanism, which can achieve efficient transmission of the power of the pitch mechanism and ensure the stability and accuracy of the blade segment during the pitch change process.

[0017] In an optional embodiment, the connecting member is a hollow cylinder.

[0018] Beneficial Effects

[0019] The connector is designed as a hollow cylinder, which not only reduces the overall weight of the connection assembly, but also facilitates the position arrangement of the variable pitch mechanism in the blade segment. The hollow cylinder design of the connector improves the structural strength of the wind turbine blade while reducing the manufacturing difficulty and cost of the wind turbine blade.

[0020] In an optional embodiment, the pitch mechanism includes: a pitch drive, a flexible connecting shaft and a pitch gear, the pitch drive is connected to the pitch gear via the flexible connecting shaft, and the pitch gear is connected to the connecting member.

[0021] Beneficial Effects

[0022] The use of a flexible connecting shaft enhances the adaptability of the pitch mechanism to external forces and pitch angles, reduces mechanical losses and failure rates during the pitch process, and improves the control accuracy of the pitch mechanism.

[0023] In an optional embodiment, it also includes a reinforcement component, a group of the reinforcement components are provided at the end of the blade segment located at the root away from the hub, a group of the reinforcement components are provided at the end of the blade segment located at the tip close to the hub, and a group of the reinforcement components are provided at both ends of each of the remaining blade segments.

[0024] Beneficial Effects

[0025] The reinforcement component effectively avoids the position deviation of the connecting component in the blade segment and ensures the position accuracy of the connecting component in the blade. At the same time, the reinforcement component also effectively enhances the overall strength and anti-deformation ability of the blade structure.

[0026] In an optional embodiment, the reinforcement assembly includes two main beams and two webs, the two main beams are relatively arranged on both sides of the inner wall of the blade segment, the two webs are arranged on both sides of the connecting member, and the two ends of the webs are respectively connected to the two main beams.

[0027] Beneficial Effects

[0028] The main beams are relatively arranged on both sides of the inner wall of the blade segment, making the outer structure strength of the blade segment more stable and improving the bending and torsion resistance of the blade. The webs are on both sides of the connecting piece and connected to the two main beams, which improves the structural strength of the connecting piece and prevents the connecting piece from being offset in the blade segment.

[0029] In an optional embodiment, a fairing is provided between two adjacent blade segments.

[0030] Beneficial Effects

[0031] The fairing can effectively reduce the air flow turbulence between the blade segments during the rotation of the blades, reduce the overall wind resistance and airflow loss of the blades, and improve the aerodynamic efficiency of the blades and the overall power generation capacity of the fan.

[0032] In an optional embodiment, a detection device is provided on each of the blade segments.

[0033] Beneficial Effects

[0034] The detection device can monitor the deformation degree of the blade segment in real time, quickly discover abnormal deformation of the blade segment and provide timely feedback, so as to avoid affecting the overall power generation efficiency of the wind turbine due to excessive deformation of the blade segment.

[0035] In an optional embodiment, a barrier cover is provided outside the detection device.

[0036] Beneficial Effects

[0037] The barrier cover can provide good protection for the detection device, prevent the detection device from being affected by external environmental factors, and improve the durability and measurement accuracy of the detection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A structural diagram of a wind turbine blade capable of variable pitch in sections according to an embodiment of the present invention;

[0040] Figure 2 The present invention is a structural diagram of a blade segment close to the hub in a wind turbine blade capable of segmented pitch change;

[0041] Figure 3 A schematic diagram of a blade segment connection of a wind turbine blade capable of segmented pitch change;

[0042] Figure 4 The present invention is a schematic diagram of the structure of a fairing for a wind turbine blade with segmented variable pitch.

[0043] Description of reference numerals:

[0044] 11. blade segment, 111. detection device;

[0045] 21. Connectors;

[0046] 311. pitch drive, 312. flexible connecting shaft, 313. pitch gear;

[0047] 41, main beam, 42, web;

[0048] 51. Fairing. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0050] Combine the following Figures 1 to 4 , describing an embodiment of the present invention.

[0051] According to an embodiment of the present invention, on the one hand, a wind turbine blade with segmented pitch control is provided, comprising: a blade, a connection assembly and a pitch control assembly. The blade comprises a plurality of blade segments 11, and a blade segment 11 located at the root is connected to the hub; the connection assembly comprises a plurality of connecting members 21, and a connecting member 21 is arranged in each blade segment 11; the pitch control assembly comprises a plurality of sets of pitch control mechanisms, wherein one set of pitch control mechanisms is arranged in the hub, and its driving end is connected to the blade segment 11 located at the root, and the remaining pitch control mechanisms are arranged at the connection of two adjacent blade segments 11, and a set of pitch control mechanisms is arranged in the connecting member 21 in one of the blade segments 11 close to the hub of the two adjacent blade segments 11, and the driving end of the pitch control mechanism is connected to the connecting member in one of the blade segments 11 far from the hub.

[0052] The blade has an overall curved airfoil structure, with two main edges, the leading edge and the trailing edge. The leading edge is relatively smooth and can divert the windward airflow; the trailing edge is relatively sharp and can form a low-pressure area to generate lift. The blade includes a plurality of blade segments 11, and the blade segments 11 are connected in sequence. The number of blade segments 11 is adaptively adjusted according to the overall length of the blade, and the plurality of blade segments 11 are connected in sequence from the root to the tip of the blade. Specifically, in this embodiment, the blade includes three blade segments 11. The blade segment 11 is a hollow structure, and the cross-section of each blade segment 11 is composed of an inner and outer two-layer structure. The outer layer is a composite material skin, which is used to provide aerodynamic performance and protection functions; the inner layer uses a reinforcing rib frame structure, which can improve the structural strength and torsion resistance of the blade.

[0053] The connection assembly includes a plurality of connecting members 21, and a connecting member 21 is arranged in each blade segment 11, and the shape of the connecting member 21 is cylindrical. The connection member 21 is used to realize the setting of the pitch mechanism and the driving of the blade segment 11. The pitch assembly includes a plurality of groups of pitch mechanisms, and the number of pitch mechanisms, connecting members 21 and blade segments 11 is one-to-one corresponding. One group of pitch mechanisms is arranged on the hub of the wind turbine, and the driving end of the pitch mechanism is connected to the end of the connecting member 21 in a blade segment 11 at the root of the blade close to the hub, so as to realize the pitch adjustment of the blade segment 11 at the root of the blade. The remaining pitch mechanisms are respectively arranged inside the connecting members 21 of the remaining blade segments except the blade segment at the tip of the blade, and the pitch mechanism is arranged on the end of the connecting member 21 inside the blade segment 11 away from the hub, and the driving end of the pitch mechanism is connected to another adjacent connecting member 21, so as to realize the pitch adjustment of the blade segment 11 corresponding to the connecting member 21.

[0054] The blade adopts a segmented independent pitch design, and each blade segment 11 can be individually pitched. The individual pitch adjustment of the blade segment 11 effectively reduces the torque of each pitch mechanism and reduces the load pressure of the pitch mechanism. At the same time, controlling the pitch angle of each blade segment 11 according to different wind speed conditions can also significantly optimize the power generation efficiency of the wind turbine.

[0055] In one embodiment, the outer diameters of the plurality of connecting members 21 in the blade decrease gradually from the root of the blade to the tip of the blade.

[0056] Since the blade needs to withstand large bending moments and torques in the root area, a larger outer diameter of the connecting piece 21 can provide higher structural strength and rigidity for the blade root. The outer diameter of the blade tip connecting piece 21 gradually decreases, and the weight of the blade tip is greatly reduced, which can reduce the inertia and centrifugal force of the blade during rotation, and also reduce the overall weight of the blade and the load on the fan main shaft.

[0057] In one embodiment, one end of the connecting member 21 in one of the two adjacent blade segments 11 away from the hub extends into the connecting member 21 in the other blade segment 11 and is connected to the driving end of the pitch mechanism.

[0058] A connecting piece 21 is provided in each blade segment 11, and the connecting piece 21 is fixedly connected to the blade segment 11, so that when the pitch mechanism drives the connecting piece to rotate, the blade segment can be driven to rotate accordingly. Two adjacent connecting pieces 21 are inserted into each other, that is, the connecting piece 21 with a smaller diameter is inserted into the other connecting piece 21 with a larger diameter, or a connecting piece near the tip of the blade is inserted into a connecting piece near the root of the blade, so as to be connected to the pitch mechanism.

[0059] In one embodiment, the connecting member 21 is a hollow cylinder.

[0060] The design of the connector 21 as a hollow cylinder structure can effectively reduce the weight of the overall structure of the blade. The connector 21 needs to withstand the bending moment and torque generated when the blade rotates, and the closer to the root of the blade, the greater the bending moment and torque that the connector 21 withstands. In order to ensure that the hollow cylinder structure of the connector 21 does not deform or break when the blade rotates, the wall thickness of the hollow cylinder is relatively thick at the root of the blade and gradually thins toward the tip. This wall thickness design enables the connector 21 to reasonably distribute the stress of the force exerted on the blade during rotation, ensuring that the blade has sufficient stability during high-speed rotation. At the root of the blade, because it needs to withstand greater torque and pressure, the wall thickness of the hollow cylinder is increased to enhance its load-bearing capacity; at the tip of the blade, the wall thickness of the hollow cylinder is reduced, thereby reducing the weight of the overall structure and reducing the inertia force of the blade.

[0061] In one embodiment, the pitch mechanism includes: a pitch drive 311 , a flexible connecting shaft 312 and a pitch gear 313 , the pitch drive 311 is connected to the pitch gear 313 via the flexible connecting shaft 312 , and the pitch gear 313 is connected to the connector 21 .

[0062] Except for the pitch drive of one set of pitch mechanisms which is arranged on the wheel hub, the other pitch drives 311 are respectively arranged in the connecting piece corresponding to each blade segment 11 at one end away from the wheel hub, and are fixed to the inner wall of the connecting piece by a support frame or a fixed seat. In this embodiment, the pitch drive is preferably a motor. The flexible connecting shaft 312 serves as a power transmission component between the pitch drive 311 and the pitch gear 313, and the bearing at one end is connected to the output end of the pitch drive 311, and the other end is connected to the pitch gear 313 through a coupling. Since the blade will produce a certain degree of distortion and angle deviation during the pitch adjustment process, the flexible connecting shaft 312 can effectively adapt to these changes, prevent excessive stress and structural damage that may be caused by the rigid shaft transmission system, and ensure that the blade segment 11 successfully completes the pitch action. Generally, three pitch gears 313 are arranged evenly around the periphery of the connecting piece to be driven, and mesh with the connecting piece, and the power is output by the pitch drive to achieve the adjustment of the angle of the blade segment 11.

[0063] In one embodiment, the wind turbine blade with segmented pitch control also includes a reinforcement component, a group of reinforcement components is provided at the end of the blade segment 11 located at the root away from the hub, a group of reinforcement components is provided at the end of a group of blade segments 11 located at the tip close to the hub, and a group of reinforcement components is provided at both ends of each of the remaining blade segments 11.

[0064] The provision of the reinforcement component can greatly improve the bending and torsion resistance of the blade, and at the same time limit the connection member 21 in the blade segment 11 to prevent the connection member 21 from being displaced during the pitch change process of the blade segment 11.

[0065] In one embodiment, the reinforcement assembly includes two main beams 41 and two webs 42 . The two main beams 41 are relatively arranged on both sides of the inner wall of the blade segment 11 , and the two webs 42 are arranged on both sides of the connecting member 21 , and the two ends of the webs 42 are respectively connected to the two main beams 41 .

[0066] The main beam 41 is arranged along both sides of the inner wall of the blade and is fixed to the inner wall of the blade segment 11 by bolts or welding, ensuring that the reinforcement assembly can stably transmit external loads. Since the blade generates centrifugal force and wind pressure during rotation, in order to ensure that the main beam 41 has sufficient rigidity and strength during the rotation of the blade, the main beam 41 is made of high-strength alloy material or steel. The web 42 serves as a connection between the main beam 41 and the blade segment 11. The web 42 is arranged on both sides of the connecting member 21 and is connected to the main beam 41 by bolts or welding, ensuring that the overall structure of the reinforcement assembly is more stable. When the blade vibrates or is subjected to a large load during the pitch change process or under the action of wind, the presence of the web 42 effectively limits the lateral or longitudinal displacement of the connecting member 21, so that the connecting member 21 always remains in the correct position, preventing external forces that may cause the connecting member 21 to loosen or deviate, avoiding loosening or misalignment of the connection, and ensuring the structural stability of the blade.

[0067] In one embodiment, a fairing 51 is disposed between two adjacent blade segments 11 .

[0068] The fairing 51 is arranged at the connection of adjacent blade segments 11, and plays a certain protective role on the connecting piece 21 between the blade segments 11. The fairing 51 is designed to be similar to the shape of the blade, and the outer surface conforms to the aerodynamic principle, which can smoothly guide the airflow through the connection area between the blade segments 11, and effectively reduce the disturbance of the airflow at the blade connection.

[0069] In one embodiment, a detection device 111 is disposed on each blade segment 11 .

[0070] The detection device 111 is arranged inside the blade segment 11 and fixed on the inner wall of the blade segment 11. The detection device 111 is mainly used to monitor the state of the blade segment 11 during operation in real time, including parameters such as deformation, vibration and pressure of the blade. When the deformation degree of the blade segment 11 is large, the detection device 111 will feed back the data to the pitch mechanism, and the pitch mechanism will pitch the blade segment 11 to reduce the wind-receiving area of ​​the blade segment 11, thereby reducing the deformation degree of the blade segment 11.

[0071] In one embodiment, a barrier cover is disposed outside the detection device 111 .

[0072] The barrier cover is a shell structure, which is arranged outside the detection device 111 and is used to protect the detection device 111 from external environmental factors and ensure its stable operation under harsh working conditions.

[0073] The working process of the wind turbine blade with segmented pitch change provided in this embodiment is described as follows:

[0074] The blades will rotate after the wind turbine is turned on, and the external wind speed will affect the rotation of the blades. A detection device 111 is set on each blade segment 11, which can monitor the wind speed around the blade segment 11, the deformation, vibration and pressure of the blade in real time. Each pitch mechanism will adjust the pitch angle of each blade segment 11 according to the deformation degree of each blade segment 11 and the operating state of the wind turbine, so that the blade segment 11 reaches the optimal pitch angle of the current wind speed. The pitch adjustment of the blade segment 11 is driven by the pitch driver 311, and the driving force is transmitted through the flexible connecting shaft 312 and the pitch gear 313 to complete the pitch adjustment of the blade segment 11. When the wind speed is low, the pitch mechanism adjusts the pitch angle of the blade segment 11 to increase the capture of wind energy; when the wind speed is high, the pitch mechanism adjusts the pitch angle of the blade to reduce the wind-receiving area of ​​the blade, thereby avoiding overload and maintaining stable power generation output.

[0075] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A wind turbine blade with segmented pitch control, characterized in that: include: A blade, the blade comprising a plurality of blade segments (11), wherein one blade segment (11) located at a root is connected to a hub; A connecting assembly, the connecting assembly comprising a plurality of connecting members (21), and one connecting member (21) is arranged in each of the blade segments (11); A pitch component, the pitch component comprising a plurality of pitch mechanisms, wherein one set of pitch mechanisms is arranged at the hub, and a driving end thereof is connected to the blade segment (11) located at the root, and the remaining pitch mechanisms are respectively arranged at the connection between two adjacent blade segments (11), and a set of pitch mechanisms is arranged in the connecting piece (21) in one of the blade segments (11) close to the hub of the two adjacent blade segments (11), and a driving end of the pitch mechanism is connected to the connecting piece (21) in one of the blade segments (11) far from the hub.

2. The wind turbine blade with segmented pitch control according to claim 1, characterized in that: The outer diameters of the multiple connecting parts (21) in the blade decrease gradually from the root of the blade to the tip of the blade.

3. The wind turbine blade with segmented pitch control according to claim 1, characterized in that: One end of the connecting piece (21) in one of the blade segments (11) away from the hub of two adjacent blade segments (11) extends into the connecting piece (21) in the other blade segment (11) and is connected to the driving end of the pitch mechanism.

4. The wind turbine blade with segmented pitch control according to claim 3, characterized in that: The connecting piece (21) is a hollow cylinder.

5. The wind turbine blade with segmented pitch control according to claim 1, characterized in that: The pitch mechanism comprises: a pitch drive (311), a flexible connecting shaft (312) and a pitch gear (313); the pitch drive (311) is connected to the pitch gear (313) via the flexible connecting shaft (312); and the pitch gear (313) is connected to the connecting member (21).

6. The wind turbine blade with segmented pitch control according to claim 1, characterized in that: It also includes a reinforcement component, wherein a group of the reinforcement components are arranged at one end of the blade segment (11) located at the root and away from the wheel hub, a group of the reinforcement components are arranged at one end of the blade segment (11) located at the tip and close to the wheel hub, and a group of the reinforcement components are arranged at both ends of each of the remaining blade segments (11).

7. The wind turbine blade with segmented pitch control according to claim 6, characterized in that: The reinforcement assembly comprises two main beams (41) and two webs (42), wherein the two main beams (41) are arranged oppositely on both sides of the inner wall of the blade segment (11), and the two webs are arranged on both sides of the connecting member (21), and the two ends of the webs are respectively connected to the two main beams.

8. The wind turbine blade with segmented pitch control according to any one of claims 1 to 7, characterized in that: A fairing (51) is arranged between two adjacent blade segments (11).

9. The wind turbine blade with segmented pitch control according to claim 1, characterized in that: A detection device (111) is provided on each blade segment (11).

10. The wind turbine blade with segmented pitch control according to claim 9, characterized in that: A barrier cover is arranged outside the detection device (111).

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