Fan blade, fan, and fan blade anti-sweeping method

Abstract

The application discloses a fan blade, a fan and a fan blade anti-sweeping method. The main blade and the tail blade of the fan blade are detachably connected through a connecting assembly. The fan blade further comprises a position detection device for detecting the distance between the fan blade and the fan tower drum. The connecting assembly can release the connection of the main blade and the tail blade when the minimum distance is less than a threshold value. During the operation of the fan, the position detection device is used to actively detect the distance between the fan blade and the fan tower drum. When the fan blade is at risk of sweeping the fan tower drum, the connecting assembly can timely release the connection of the main blade and the tail blade, so that the tail blade is separated from the main blade, thereby avoiding the fan blade from sweeping the fan tower drum, reducing the damage degree and economic loss of the fan, and reducing the difficulty of subsequent repair work of the fan.

Description

Technical Field

[0001] This invention relates to the field of wind turbine power generation technology, specifically to a wind turbine blade, a wind turbine, and a method for preventing wind turbine blade swiping. Background Technology

[0002] Wind power, as a new type of energy, is being used more and more widely. In recent years, with the development of wind power technology, the power of wind turbines has increased, the corresponding blades have become longer, and the required tower height and diameter have also increased. Due to the imperfections of the wind turbine control system, there are often delays or overreactions in the control of blades when they deform under wind, frequently resulting in blade sweeping. Steel towers, being thin-walled structures, typically have a diameter of 4m to 5m and a wall thickness of 15mm to 40mm, making them highly susceptible to tower collapse during sweeping. Even if the blade rotation speed is low and tower collapse does not occur during sweeping, the blade will break, requiring complete replacement. Subsequent blade replacement requires not only the cost of the blade itself but also the deployment of a 1000t-class main crane, resulting in extremely high costs and significant losses. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art in which wind turbine blades sweep against the tower, causing blade damage and tower collapse, and to provide a wind turbine blade, wind turbine, and wind turbine blade anti-sweeping method.

[0004] The present invention solves the above-mentioned technical problems through the following technical solution:

[0005] A wind turbine blade includes a main blade close to the main unit of the wind turbine, a tail blade away from the main unit of the wind turbine, and a connecting assembly, wherein the main blade and the tail blade are detachably connected by the connecting assembly.

[0006] The wind turbine blades also include a position detection device, which is used to detect the distance between the wind turbine blades and the wind turbine tower;

[0007] The connection component can disconnect the main blade and the tail blade when the distance is less than a threshold.

[0008] In this technical solution, the wind turbine blade is divided into two parts: a main blade and a tail blade, connected by a connecting assembly. A position detection device is also included to monitor the distance between the wind turbine blade and the tower during operation, and controls a limit device based on this distance. The connecting assembly can maintain or disengage the connection between the main blade and the tail blade based on feedback from the position detection device. When the distance between the wind turbine blade and the tower is not less than a threshold, the main blade and tail blade remain connected; when the distance is less than the threshold, the connection is disengaged, allowing the tail blade to detach from the main blade under centrifugal force, thus preventing the wind turbine blade from swiping against the tower and achieving active anti-swiping of the wind turbine blade.

[0009] Preferably, the connection component includes:

[0010] A first connector and a second connector are respectively disposed on the main blade and the tail blade. The second connector is sleeved on the outside of the first connector. The inner surface of the second connector abuts against the outer surface of the first connector. The first connector has a first limiting hole and the second connector has a second limiting hole. The first limiting hole and the second limiting hole are correspondingly disposed.

[0011] A fastener, the two ends of which are respectively inserted into the first limiting hole and the second limiting hole provided accordingly, the structure of the second limiting hole being configured to restrict the degree of freedom of the fastener to move away from the first limiting hole;

[0012] An elastic element is provided for applying a force to the fixing member to disengage it from the second limiting hole in the direction of the first limiting hole;

[0013] A limiting device is provided to restrict the fixing member from disengaging from the second limiting hole, and to release the restriction on the fixing member when the distance is less than a threshold.

[0014] In this technical solution, the connecting assembly specifically achieves the connection between the main blade and the tail blade by simultaneously inserting a fixing member into the first and second limiting holes of both the main blade and the tail blade. An elastic element is incorporated to allow the fixing member to disengage from the second limiting hole. Specifically, when the distance between the wind turbine blade and the wind turbine tower is not less than a threshold value, the fixing member is confined within the first and second limiting holes by the limiting device, maintaining the connection between the main blade and the tail blade. When the distance between the wind turbine blade and the wind turbine tower is less than the threshold value, the limiting device releases the constraint on the fixing member, allowing it to disengage from the second limiting hole under the action of the elastic element, thus preventing the main blade and the tail blade from maintaining their connection.

[0015] Preferably, the limiting device includes:

[0016] An airbag abuts against one end of the fixing member that is closer to the first limiting hole, in order to prevent the fixing member from disengaging from the second limiting hole;

[0017] An explosive device for detonating the airbag;

[0018] The controller is connected to the blasting device and the position detection device respectively. The controller is used to obtain the minimum distance detected by the position detection device and control the blasting device to start when the minimum distance is less than a threshold.

[0019] In this technical solution, an airbag is used to limit the pin, and a controller and a bursting device are used to control whether the airbag bursts. The airbag has a lightweight structure, which reduces the burden on the wind turbine blades, and the overall structure is simple and reliable.

[0020] Preferably, the first limiting hole and the second limiting hole extend along the normal direction of the outer surface of the first connector, and the airbag is disposed within the inner surface of the first connector.

[0021] Preferably, the first connector is disposed on the main blade and integrally formed with the main blade; the second connector is disposed on the tail blade and integrally formed with the tail blade.

[0022] In this technical solution, by integrally molding the first connector with the main blade and the second connector with the tail blade, the connection between the first connector and the main blade, and the second connector and the tail blade, can be made more reliable. On the other hand, there is no need to drill holes in the main blade and the tail blade, so that the main blade and the tail blade can be detachably connected without affecting the structural strength of the main blade and the tail blade.

[0023] Preferably, the elastic element is compressed within the second limiting hole, and along the extension and retraction direction of the elastic element, both ends of the elastic element abut against the bottom wall of the second limiting hole and the fixing element, respectively.

[0024] Preferably, there are multiple second limiting holes and multiple first limiting holes, and the second limiting holes and the first limiting holes are arranged in a one-to-one correspondence. The fixing member is inserted into at least one of the corresponding second limiting holes and the first limiting hole.

[0025] Preferably, the first connecting member is a first connecting ring, the second connecting member is a second connecting ring, and the inner circumferential surface of the second connecting ring abuts against the outer circumferential surface of the first connecting ring.

[0026] Preferably, the fastener comprises a rectangular pin.

[0027] Preferably, the length of the fan blade is L, and the length of the tail blade is a, where 0.05L≤a≤0.15L.

[0028] A wind turbine, the wind turbine comprising a wind turbine tower and wind turbine blades as described above.

[0029] Preferably, the wind turbine also includes a nacelle, and the position detection device is disposed at the bottom of the nacelle.

[0030] A method for preventing wind turbine blade swiping includes the following steps:

[0031] The wind turbine blades are divided along the blade axis into main blades that are close to the main wind turbine and tail blades that are far from the main wind turbine. The main blades and the tail blades are connected by a connecting assembly.

[0032] The distance from the wind turbine blade to the wind turbine tower is detected. If the distance is less than the threshold corresponding to the detected point, a control signal is sent to the connecting component, and the connecting component controls the tail blade to detach from the main blade.

[0033] In this technical solution, the wind turbine blade is divided into two parts: the main blade and the tail blade, which are connected by a connecting assembly. During the operation of the wind turbine blade, the distance between the wind turbine blade and the wind turbine tower is detected. If the detected distance is less than the threshold corresponding to the detected point, it indicates that there is a risk that the wind turbine blade will sweep the wind turbine tower. At this time, by sending a control signal to the connecting assembly, the tail blade is controlled to detach from the main blade, thereby preventing the wind turbine blade from sweeping the wind turbine tower, reducing the degree of damage to the wind turbine and economic losses, and reducing the difficulty of subsequent repair work.

[0034] Preferably, the distance is the minimum horizontal distance from the wind turbine blade to the wind turbine tower.

[0035] The positive and progressive effects of this invention are as follows: the wind turbine blades, wind turbine, and wind turbine blade anti-sweeping method of this invention can actively detect the distance between the wind turbine blades and the wind turbine tower during wind turbine operation. When there is a risk that the wind turbine blades will sweep the wind turbine tower, the tail blades can be detached from the main blades in time, thereby avoiding the wind turbine blades from sweeping the wind turbine tower, reducing the degree of wind turbine damage and economic losses, and reducing the difficulty of subsequent wind turbine repair work. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the wind turbine blade in Embodiment 1 of the present invention.

[0037] Figure 2 This is a schematic diagram of the main blade and the first connecting ring in Embodiment 1 of the present invention.

[0038] Figure 3 This is a schematic diagram of the tail blade and the second connecting ring in Embodiment 1 of the present invention.

[0039] Figure 4 This is a schematic diagram of the structure of the first connecting ring and the second connecting ring in Embodiment 1 of the present invention.

[0040] Figure 5 This is a partial cross-sectional structural diagram of the connection component in Embodiment 1 of the present invention.

[0041] Figure 6 for Figure 5 An enlarged schematic diagram of part A in the middle.

[0042] Explanation of reference numerals in the attached figures:

[0043] Wind turbine blade 1

[0044] Main blade 11

[0045] Tail blade 12

[0046] First connector 131

[0047] Second connector 132

[0048] Fastener 133

[0049] Elastic component 134

[0050] Airbag 135

[0051] Signal line 14 Detailed Implementation

[0052] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0053] Example 1

[0054] like Figures 1-6 As shown, this embodiment provides a fan, which includes fan blades 1 and a fan tower (not shown in the figure).

[0055] Specifically, such as Figure 1As shown, the length L of the wind turbine blade 1 is 90m. The wind turbine blade 1 includes a main blade 11 near the wind turbine main unit, a tail blade 12 away from the wind turbine main unit, and a connecting assembly. The separation point of the main blade 11 and the tail blade 12 is 5m from the blade tip a. The main blade 11 and the tail blade 12 are detachably connected by the connecting assembly. The wind turbine blade 1 also includes a position detection device (not shown in the figure), which is used to detect the distance between the wind turbine blade and the wind turbine tower. At the same time, the connecting assembly can disconnect the main blade 11 and the tail blade 12 when the distance is less than a threshold. By splitting the wind turbine blade 1 into two parts, the main blade 11 and the tail blade 12 are connected by the connecting assembly. A position detection device is also provided to detect the distance between the wind turbine blade 1 and the wind turbine tower during the operation of the wind turbine blade 1, and to control the limit device based on this distance. The connecting assembly can maintain or disengage the connection between the main blade 11 and the tail blade 12 based on the feedback from the position detection device. When the distance between the wind turbine blade 1 and the wind turbine tower is not less than the threshold, the main blade 11 and the tail blade 12 are kept connected; when the distance between the wind turbine blade 1 and the wind turbine tower is less than the threshold, the connection between the main blade 11 and the tail blade 12 is released so that the tail blade 12 can detach from the main blade 11 under the action of centrifugal force, thereby preventing the wind turbine blade 1 from sweeping into the wind turbine tower, thus realizing the active anti-sweeping of the wind turbine blade 1.

[0056] Generally speaking, the dividing point between the main blade 11 and the tail blade 12 is usually located 3m to 10m from the tip of the blade.

[0057] Specifically, such as Figures 2-6 As shown, the connecting assembly includes a first connector 131, a second connector 132, a fixing member 133, an elastic member 134, and a limiting device. The first connector 131 is disposed on the main blade 11, and the second connector 132 is disposed on the tail blade 12. The second connector 132 is sleeved on the outside of the first connector 131, with its inner surface abutting against the outer surface of the first connector 131. The first connector 131 has multiple first limiting holes for inserting the fixing member 133, and the second connector 132 also has multiple second limiting holes for inserting the fixing member 133. These first and second limiting holes are correspondingly arranged, allowing both ends of each fixing member 133 to be inserted into any set of corresponding first and second limiting holes, thus maintaining the connection between the main blade 11 and the tail blade 12. Specifically, in this embodiment, fixing members 133 are inserted into all the first and second limiting holes to distribute stress.

[0058] Meanwhile, the elastic element 134 is disposed between the fixed element 133 and the second limiting hole, exerting a force on the fixed element 133 to disengage from the second limiting hole. A limiting device is disposed at the other end of the fixed element 133 to restrict its disengagement from the second limiting hole. This limiting device can release the restriction on the fixed element 133 when the minimum distance is less than a threshold. Specifically, in this embodiment, the first limiting hole is a through hole, providing clearance for the elastic element 134 to disengage from the second limiting hole; the second limiting hole is a blind hole, to restrict the degree of freedom of the fixed element to move away from the first limiting hole. Simultaneously, the second limiting hole also facilitates the compression of the elastic element within it by having its two ends abut against the bottom wall of the blind hole and the fixed element 133 respectively, thus providing a force on the fixed element 133 to disengage from the second limiting hole. The threshold setting is related to the detection point of the position detection device; different detection points have different thresholds. This threshold is existing technology; that is, the threshold for different detection points can be determined based on statistical data or calculation methods in the prior art, and will not be elaborated further here.

[0059] Specifically, in this embodiment, the position detection device detects the minimum distance between the wind turbine blades and the wind turbine tower. Furthermore, the position detection device used in this embodiment is existing technology, such as a photoelectric position sensor, and will not be described in detail here.

[0060] In other words, in this embodiment, the connecting assembly specifically connects the main blade 11 and the tail blade 12 by inserting the fixing member 133 into the first limiting hole and the second limiting hole. An elastic member 134 is provided to allow the fixing member 133 to disengage from the second limiting hole. A position detection device is also provided so that during the operation of the wind turbine blade 1, the connecting assembly can detect the distance between the wind turbine blade 1 and the tower, and control the limiting device based on this distance. Specifically, when the distance between the wind turbine blade 1 and the wind turbine tower is not less than the threshold corresponding to the detection point, the limiting device restricts the pin in the first and second limiting holes, keeping the main blade 11 and the tail blade 12 connected. When the distance between the wind turbine blade 1 and the wind turbine tower is less than the threshold corresponding to the detection point, the limiting device releases the restriction on the fixing member 133, causing the fixing member 133 to disengage from the second limiting hole under the action of the elastic member 134, thus preventing the main blade 11 and the tail blade 12 from maintaining their connection.

[0061] Of course, in other embodiments, the second limiting hole can also be set as other structural forms in the prior art that can restrict the degree of freedom of the fixing member to move away from the first limiting hole. For example, the second limiting hole can be set as a through hole. In this case, a protrusion can be provided on the inner circumferential side surface of the second limiting hole. The compression of the elastic member is achieved by the abutment of the protrusion with the elastic member. This will not be elaborated here.

[0062] Furthermore, in this embodiment, since the main blade 11 is still intact, when repairing the wind turbine blade 1, only the new tail blade 12 needs to be reinstalled, instead of replacing the entire wind turbine blade 1, thus reducing the material cost of repair. In addition, the tail blade 12 is shorter and lower than the ground, so a large-tonnage main crane is not required for repair; a truck crane of about 100t is sufficient. This further reduces the mechanical cost of repairing the wind turbine blade 1 and greatly shortens the repair period, thereby reducing the loss of normal power generation caused by wind turbine maintenance.

[0063] Meanwhile, since the main blade 11 and the tail blade 12 are connected by the first connector 131 and the second connector 132, the first connector 131 and the second connector 132 have a certain length along the length direction of the wind turbine blade 1, which ensures that the connection between the main blade 11 and the tail blade 12 can withstand a certain shear force and bending moment, and prevents the wind turbine blade 1 from bending at the connection between the main blade 11 and the tail blade 12.

[0064] Of course, in other embodiments, the main blade and the tail blade can be detachably connected by other connecting components in the prior art. Alternatively, in more embodiments, the first connecting member can be disposed on the tail blade and the second connecting member can be disposed on the main blade, which will not be elaborated here.

[0065] Specifically in this embodiment, such as Figures 2-4 As shown, the first connecting member 131 is a first connecting ring, and its cross-sectional shape matches the thicker portion of the main blade, with an arc-shaped treatment near the thinner portion of the main blade. The second connecting ring matches the cross-sectional shape of the tail blade, and its cross-sectional shape also matches the thicker portion of the tail blade, with an arc-shaped treatment near the thinner portion of the tail blade. The inner circumferential surface of the second connecting ring abuts against the outer circumferential surface of the first connecting ring. By setting the first connecting member 131 and the second connecting ring into ring shapes, and matching their shapes to the cross-sectional shape of the thicker portion of the blade, the connection between the first connecting member 131 and the main blade, and the connection between the second connecting member 132 and the tail blade, are made more reliable.

[0066] Of course, in other embodiments, the first connector and the second connector can also be block-shaped or sheet-shaped connectors that meet the connection strength requirements. When the first connector or the second connector is a block-shaped or sheet-shaped connector, the inner and outer surfaces of the second connector of the first connector are distinguished as follows: perpendicular lines are drawn from the center of the connection position of the main blade and the tail blade to the first connector and the second connector, respectively. The surface that the perpendicular line passes through first is the inner surface, and the surface that it passes through later is the outer surface.

[0067] Specifically, in this embodiment, the fixing member 133 is a rectangular pin.

[0068] Of course, in other embodiments, the fastener may also be a part with a relatively smooth peripheral surface to facilitate disengagement from the second limiting hole, such as a circular pin or a nail, which will not be elaborated here.

[0069] Specifically in this embodiment, such as Figure 5 and Figure 6 As shown, the limiting device includes an airbag 135, a bursting device (not shown), and a controller (not shown). The airbag 135 abuts against the end of the fixing member 133 closest to the first limiting hole. The airbag 135 is filled with nitrogen gas, and its pressure can prevent the fixing member 133 from popping out of the hole in the fixing member 133. The bursting device is installed on the airbag 135 to detonate the airbag 135. The position detection device and the controller are installed at the bottom of the nacelle. The controller is connected to the bursting device and the position detection device respectively. The controller is used to obtain the distance detected by the position detection device and control the bursting device to detonate the airbag 135 when the distance is less than a threshold. By using the airbag 135 to limit the fixing member 133, and using the controller and bursting device to control whether the airbag 135 bursts, the airbag 135 has a lightweight structure, which reduces the burden on the wind turbine blades 1, and the overall structure is simple and reliable.

[0070] Specifically, during the operation of the wind turbine blade 1, the position detection device detects the distance between the wind turbine blade 1 and the wind turbine tower and sends the detection signal to the controller. The controller then detonates the device based on this detection signal. Specifically, when the position detection device detects that the distance between the wind turbine blade 1 and the wind turbine tower is not less than a threshold, the controller does not send a signal to the detonating device, and the detonating device does not detonate the airbag 135, allowing the inflated airbag 135 to abut against the fixing member 133, which keeps the main blade 11 and the tail blade 12 connected. However, when the position detection device detects that the distance between the wind turbine blade 1 and the wind turbine tower is less than the threshold, the controller sends a signal to the detonating device, controlling it to detonate the airbag 135. The outer side of the fixing member 133 loses the restraint of the airbag 135 and, pushed by the elastic member 134, disengages from the second limiting hole, causing the main blade 11 and the tail blade 12 to lose connection, and the tail blade 12 detaches from the main blade 11. Of course, in other embodiments, other solutions existing in the prior art can also be used to make the pin disengage from the second limiting hole when the distance between the wind turbine blade 1 and the wind turbine tower is too close, so that the tail blade 12 falls off. This will not be elaborated here.

[0071] In this embodiment, as Figure 5As shown, the position detection device is electrically connected to the controller via signal line 14, and the controller is electrically connected to the blasting device via signal line 14. The signal line 14 connected to the blasting device is connected to the controller via a slip ring inside the nacelle to prevent the signal line 14 from becoming tangled due to the continuous rotation of the fan blades, thus enabling signal transmission between the position detection device, the controller, and the blasting device. Of course, in other embodiments, the position detection device, the controller, and the blasting device can also transmit signals via wireless transmission or other methods, which will not be elaborated upon here.

[0072] In this embodiment, as Figure 2 , Figure 3 and Figure 4 As shown, the overall shape of the first connector 131 and the second connector 132 is approximately the same as the cross-sectional shape of the fan blade 1. Specifically, the overall shape of the first connector 131 and the second connector 132 matches the cross-section of the thicker part of the fan blade 1, and a rounded transition is used at the trailing edge of the blade. Furthermore, in this embodiment, the outer diameter of the first connector exactly matches the inner diameter of the second connecting ring, and their lengths also match each other.

[0073] Specifically, the first connector 131 has an L-shaped cross-section, with a portion of it protruding towards the tail blade 12 relative to the main blade 11. The root of the first connector 131 has a thickness of 15cm and a length of 30cm, while the protruding portion has a length of 40cm and a thickness of 5cm. The second connector 132 has a rectangular cross-section, with a length of 40cm and a thickness of 10cm. In other words, the outer diameter of the protruding portion of the L-shaped first connector matches the inner diameter of the second connector ring, and the length of the protruding portion of the first connector matches the length of the second connector, so that the outer periphery of the protruding portion of the first connector abuts against the inner periphery of the second connector. The second connector 132 is disposed at the end of the tail blade 12 near the main blade 11, so that after the main blade 11 and the tail blade 12 are aligned, a rectangular space is formed between the first connector 131 and the tail blade 12. The first connector 131 is located exactly in this rectangular space. The outer periphery of the protruding part of the second connector 132 relative to the main blade 11 abuts against the inner periphery of the second connector 132. The connecting ring formed by the first connector 131 and the second connector 132 after abutting has a rectangular cross-section. The width of this rectangle is the thickness of the connecting ring, which is 15cm, and the length of this rectangle is the total width of the first connector 131, which is 70cm. In addition to connecting the main blade 11 and the tail blade 12, this connecting ring, by matching the L-shaped cross-section of the first connector, can further improve the shear force and bending moment resistance at the connection point of the main blade 11 and the tail blade 12.

[0074] Of course, in other embodiments, the overall shape of the first connecting ring and the second connecting ring can also be circular, elliptical, etc. The closer the overall shape of the first connecting ring and the second connecting ring is to the shape of the fan cross section, the higher the fit between the first connecting ring and the second connecting ring and the fan blade, and the more reliable the connection. This will not be elaborated further here.

[0075] Specifically, in this embodiment, the first connector 131 and the main blade 11 are integrally formed, and the second connector 132 and the tail blade 12 are integrally formed. By integrally forming the first connector 131 with the main blade 11 and the second connector 132 with the tail blade 12, the connection between the first connector 131 and the main blade 11, and between the second connector 132 and the tail blade 12, is made more reliable. Furthermore, there is no need to drill holes in the main blade 11 and the tail blade 12, allowing for a detachable connection between the main blade 11 and the tail blade 12 without affecting their structural strength.

[0076] Of course, in other embodiments, the first connecting ring and the fan blades, and the second connecting ring and the fan blades, can also be connected in other ways.

[0077] In this embodiment, the first limiting hole and the second limiting hole extend along the normal direction of the outer peripheral surface of the first connecting ring, and the airbag 135 is disposed inside the inner peripheral surface of the first connecting ring. That is, the first connecting ring is sleeved on the outside of the airbag 135, and the fixing member 133 is perpendicular to the outer peripheral surface of the second connecting ring. Since the outer peripheral surface of the first connecting ring is curved, the normal direction of the outer peripheral surface of the first connecting ring referred to here is the normal direction of the tangent plane at the intersection of the axis of the first limiting hole and the outer peripheral surface of the first connecting ring.

[0078] In other embodiments, when the first connector and the second connector are block-shaped or sheet-shaped connectors, the first limiting hole extends along the normal direction of the plane containing the outer surface of the first connecting ring.

[0079] In this embodiment, the fixing member 133 is a rectangular steel plate pin. The length of the fixing member 133 is approximately 5cm smaller than the sum of the lengths of the first limiting hole and the second limiting hole, i.e., the length of the fixing member 133 is 10cm, the width is 199mm, and the thickness is 39mm. The elastic member 134 is compressed within the second limiting hole. Along the extension and contraction direction of the elastic member 134, both ends of the elastic member 134 abut against the bottom wall of the second limiting hole and the fixing member 133, respectively. Specifically, in this embodiment, the elastic member 134 is a helical spring. By compressing the helical spring within the second limiting hole, a force is applied to the fixing member 133 to disengage from the second limiting hole, resulting in a simple and reliable structure.

[0080] Of course, in other embodiments, the pin can also be a steel cylinder, and the specific size of the pin can be adjusted according to the specific size of the first connecting ring and the second connecting ring, which will not be elaborated here.

[0081] Specifically, in this embodiment, there are eight second limiting holes and eight first limiting holes, with each of the eight second limiting holes corresponding to one of the multiple first limiting holes. Simultaneously, there are also eight fixing members 133, each disposed within a corresponding first limiting hole and a corresponding second limiting hole. Furthermore, the eight first limiting holes and eight second limiting holes are evenly arranged along the circumference of the first connecting member 131 and the second connecting member 132. By providing multiple first limiting holes and multiple second limiting holes, and by evenly arranging these first limiting holes, the connection between the first connecting member 131 and the second connecting member is made more reliable.

[0082] Of course, in other embodiments, the number of the first limiting hole and the second limiting hole can be adjusted according to the size of the blade and the size of the first connecting ring and the second connecting ring. When multiple first limiting holes and multiple second limiting holes are provided, the first connecting ring and the second connecting ring are more reliable, which will not be elaborated here.

[0083] Specifically, in this embodiment, the length L of the wind turbine blade 1 is 90m, and the length a of the tail blade 12 is 5m. The length of the tail blade 12 is about 5% of the length of the entire wind turbine blade 1. When the wind turbine blade 1 is at risk of sweeping the tower, the tail blade 12 actively detaches from the main blade 11 after a length of about 5m from the tip of the wind turbine blade 1, so the wind turbine blade 1 will basically no longer sweep the tower.

[0084] Of course, in other embodiments, the length of the tail blade can be adjusted according to the actual situation depending on the size of the wind turbine blades. Generally speaking, the length of the tail blade should account for about 5% to 15% of the total length of the wind turbine blades. When there is a risk of wind turbine blades sweeping the tower, the tail blade can be separated from the main blades to avoid the situation of wind turbine blades sweeping the tower.

[0085] Example 2

[0086] This embodiment provides a method for preventing wind turbine blades from swiping, comprising the following steps: dividing the wind turbine blades along the blade axis into main blades closer to the wind turbine main unit and tail blades farther from the wind turbine main unit, with the main blades and tail blades connected by a connecting assembly; detecting the distance from the wind turbine blades to the wind turbine tower, and if the distance is less than a threshold, sending a control signal to the connecting assembly, which then controls the tail blades to detach from the main blades. By connecting the main blades and tail blades through the connecting assembly, and detecting the distance from the wind turbine blades to the wind turbine tower during wind turbine operation, if the detected distance is less than the threshold, it indicates that the wind turbine blades are at risk of swiping against the wind turbine tower. In this case, by sending a control signal to the connecting assembly, the tail blades are controlled to detach from the main blades, thereby preventing the wind turbine blades from swiping against the wind turbine tower, reducing the degree of damage to the wind turbine and economic losses, and also reducing the difficulty of subsequent repair work. Specifically, in this embodiment, the detected distance is the minimum distance from the wind turbine blades to the wind turbine tower, wherein this minimum distance is the minimum horizontal distance between the wind turbine blades and the wind turbine tower. Furthermore, the minimum distance is the minimum distance from the nearest point of the wind turbine blade to the wind turbine tower to the center of the wind turbine tower.

[0087] For example, in this embodiment, a position detection device is installed at the bottom of the wind turbine nacelle. The length of the wind turbine blade is 90m, and the threshold value is set to 0.9m. When the position detection device detects that the minimum distance between the wind turbine blade and the axis of the wind turbine tower is 0.9m or 1m at a certain moment, there is no need to send a control signal to the connecting component to control the tail blade to detach from the main blade. When the position detection device detects that the minimum distance between the wind turbine blade and the axis of the wind turbine tower is 0.88m at a certain moment, a control signal is sent to the connecting component, and the connecting component controls the tail blade to detach from the main blade to avoid the wind turbine blade sweeping the tower accident.

[0088] Of course, in other embodiments, the threshold can be set according to the actual situation of the blades and the method of measuring the minimum distance. The minimum distance from the wind turbine blade to the wind turbine tower can also be detected at various points, such as measuring the horizontal distance from the closest point of the wind turbine blade to the wind turbine tower to the outer peripheral wall of the wind turbine tower. That is to say, the threshold will also change depending on the detection point, and the selection or calculation method of the threshold is existing technology, which will not be described in detail here.

[0089] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A wind turbine blade, characterized in that, The wind turbine blades include a main blade close to the main wind turbine, a tail blade away from the main wind turbine, and a connecting assembly. The main blade and the tail blade are detachably connected by the connecting assembly. The wind turbine blades also include a position detection device, which is used to detect the distance between the wind turbine blades and the wind turbine tower; The connection component is capable of disconnecting the main blade and the tail blade when the distance is less than a threshold. The connection component includes: A first connector and a second connector are respectively disposed on the main blade and the tail blade. The second connector is sleeved on the outer periphery of the first connector. The inner surface of the second connector abuts against the outer surface of the first connector. The first connector has a first limiting hole and the second connector has a second limiting hole. The first limiting hole and the second limiting hole are correspondingly disposed. A fastener, the two ends of which are respectively inserted into the first limiting hole and the second limiting hole provided accordingly, the structure of the second limiting hole being configured to restrict the degree of freedom of the fastener to move away from the first limiting hole; An elastic element is provided for applying a force to the fixing member to disengage it from the second limiting hole in the direction of the first limiting hole; A limiting device is provided to restrict the fixing member from disengaging from the second limiting hole, and to release the restriction on the fixing member when the distance is less than a threshold.

2. The wind turbine blade as described in claim 1, characterized in that, The limiting device includes: An airbag abuts against one end of the fixing member that is closer to the first limiting hole, in order to prevent the fixing member from disengaging from the second limiting hole; An explosive device for detonating the airbag; The controller is connected to the blasting device and the position detection device respectively. The controller is used to obtain the distance detected by the position detection device and control the blasting device to detonate the airbag when the distance is less than a threshold.

3. The wind turbine blade as described in claim 2, characterized in that, The first limiting hole and the second limiting hole extend along the normal direction of the outer surface of the first connector, and the airbag is disposed within the inner surface of the first connector.

4. The wind turbine blade as described in claim 1, characterized in that, The first connector is disposed on the main blade and is integrally formed with the main blade; and / or: The second connector is disposed on the tail blade and is integrally formed with the tail blade.

5. The wind turbine blade as described in any one of claims 1-4, characterized in that, The elastic element is compressed within the second limiting hole, and along the extension and retraction direction of the elastic element, both ends of the elastic element abut against the bottom wall of the second limiting hole and the fixing element, respectively.

6. The wind turbine blade as described in any one of claims 1-4, characterized in that, There are multiple second limiting holes and multiple first limiting holes. The second limiting holes and the first limiting holes are arranged in a one-to-one correspondence. The fixing member is inserted into at least one of the corresponding second limiting holes and the first limiting hole.

7. The wind turbine blade as described in any one of claims 1-4, characterized in that, The first connector is a first connecting ring, and the second connector is a second connecting ring, wherein the inner circumferential surface of the second connecting ring abuts against the outer circumferential surface of the first connecting ring.

8. The wind turbine blade as described in any one of claims 1-4, characterized in that, The fastener includes a rectangular pin.

9. The wind turbine blade as described in any one of claims 1-4, characterized in that, The length of the wind turbine blade is L, and the length of the tail blade is a, where 0.05L≤a≤0.15L.

10. A fan, characterized in that, The wind turbine includes: a wind turbine tower; The wind turbine blade as described in any one of claims 1-9.

11. The fan as described in claim 10, characterized in that, The wind turbine also includes a nacelle, and the position detection device is located at the bottom of the nacelle.

12. A method for preventing wind turbine blade swiping, characterized in that, It includes the following steps: The wind turbine blades are divided along the blade axis into main blades that are close to the main wind turbine and tail blades that are far from the main wind turbine. The main blades and the tail blades are connected by a connecting assembly. The distance from the wind turbine blade to the wind turbine tower is detected. If the distance is less than the threshold corresponding to the detected point, a control signal is sent to the connecting component, and the connecting component controls the tail blade to detach from the main blade. The connecting assembly includes a first connector, a second connector, a fixing member, an elastic member, and a limiting device. The first connector is disposed on the main blade, and the second connector is disposed on the tail blade. The second connector is sleeved on the outside of the first connector, and the inner surface of the second connector abuts against the outer surface of the first connector. The first connector has multiple first limiting holes for the fixing member to be inserted, and the second connector also has multiple second limiting holes for the fixing member to be inserted. The first limiting holes and the second limiting holes are correspondingly arranged so that both ends of each fixing member can be inserted into any set of corresponding first limiting holes and second limiting holes to keep the main blade and the tail blade connected. The elastic element is disposed between the fixing element and the second limiting hole, and exerts a force on the fixing element to disengage from the second limiting hole. The limiting device is disposed at the other end of the fixing element to restrict the fixing element from disengaging from the second limiting hole. The limiting device can release the restriction on the fixing element when the distance is less than a threshold.

13. The wind turbine blade anti-sweeping method as described in claim 12, characterized in that, The distance is the minimum horizontal distance from the wind turbine blades to the wind turbine tower.

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