CN106762389A - Blade tip, blade of wind generating set and blade tip installation method - Google Patents

Abstract

The invention provides a blade tip, a wind turbine blade and an installation method of the blade tip. The blade tip includes: a main body, the main body including a pressure surface and a suction surface; a winglet, the winglet is formed at the end of the main body and is inclined toward the suction surface or the pressure surface; a main beam, the The main beam includes a first part disposed inside the housing formed by the pressure surface and the suction surface, and a second part extending to the outside of the housing. The wind turbine blade includes a blade root, a blade body and the blade tip. The installation method includes cutting off the original blade tip of the wind turbine blade; and installing the blade tip onto the blade body after the original blade tip is cut off. The blade tip according to the present invention can use the flow field characteristics to increase the utilization of the aerodynamic lift component of the winglet part and increase the efficiency of wind energy capture; in addition, the blade tip can be installed on the blades of the active wind turbine generator, thereby improving wind power generation. The overall efficiency and performance of the unit.

Description

Blade tip, wind turbine blade and blade tip installation method

technical field

The invention relates to the technical field of wind power generation, and more specifically, to a blade tip, a blade of a wind power generating set, and a method for installing the blade tip.

Background technique

The blade of a wind turbine is a key component used to capture wind energy in a modern wind turbine. When the blade of a wind turbine is running, the pressure on the pressure side is higher than the suction side. Under the action of the pressure difference, the airflow on the pressure side bypasses the tip of the blade. Flow to the suction side, so that the streamline on the pressure side is inclined from the blade root to the blade tip, while the streamline on the suction side is biased from the blade tip to the blade root. Since the airflow on the pressure surface and the suction surface have different flow directions at the trailing edge, a vortex is formed, and the backward flow forms a tip vortex. During operation, due to the pressure difference between the suction surface and the pressure surface, a tip vortex is formed at the blade tip. , resulting in blade tip noise and reduced overall aerodynamic efficiency of the wind turbine.

Referring to the winglets commonly used in civil aircraft, the blade design with tiplets can reduce blade tip noise and improve the overall aerodynamic efficiency of wind turbines. However, there are still many problems in the existing blades with tiplets, for example, there are trailing edge noises such as turbulent flow noise at the trailing edge of the blade tip during operation.

In addition, most of the blades of wind turbines currently in service are not equipped with tiplets, which will greatly reduce the overall efficiency and performance of wind turbines. Therefore, it is necessary to study a blade that can be installed on existing wind turbines. of leaflets.

Contents of the invention

In order to solve the problems of energy loss caused by blade tip vortex and noise generated by the trailing edge, according to one aspect of the present invention, a blade tip, a wind power generator blade including the blade tip, and a method for installing the blade tip are provided.

According to an exemplary embodiment of the present invention, there is provided a blade tip for a wind turbine blade, the blade tip comprising: a main body including a pressure surface and a suction surface; a winglet formed on the the end of the main body and bend towards the suction surface or the pressure surface; the main beam, the main beam includes a first part arranged inside the shell formed by the pressure surface and the suction surface and extends to the The second part on the outside of the enclosure.

According to an exemplary embodiment of the invention, the winglet is bent towards the suction side or the pressure side with a camber angle between 30° and 80°.

According to an exemplary embodiment of the present invention, the trailing edge of the main body and/or the trailing edge of the winglet may be provided with serrations.

Preferably, the sawtooth portion may include a plurality of sawteeth arranged continuously or discontinuously.

Preferably, the included angle between adjacent saw teeth among the plurality of saw teeth can be set between 20° and 60°.

Preferably, the included angle between adjacent saw teeth among the plurality of saw teeth may be set to 40°.

Preferably, said first portion is bondable to at least one of said pressure side and said suction side.

According to an exemplary embodiment of the present invention, the blade tip may further include: a junction box disposed on a side of the first part of the main spar.

According to an exemplary embodiment of the present invention, the blade tip further includes: a lightning arrester located at the end of the winglet, and the lightning arrester is connected to the junction box through a lightning conductor.

Wherein, the lightning arrester can be formed integrally with the winglet; or, the lightning arrester can also be detachably mounted on the winglet.

Preferably, the lightning arrester may be provided with drainage holes.

According to an exemplary embodiment of the present invention, the blade tip may further include: an operation hole formed on the suction surface or the pressure surface.

According to another exemplary embodiment of the present invention, a blade of a wind power generating set is provided, and the blade includes a blade root, a blade body, and the above-mentioned blade tip.

Wherein, the above-mentioned blade tip can be integrally formed with the blade body through integral molding, or the additionally shaped blade tip can also be installed on the blade body.

According to another exemplary embodiment of the present invention, a method for installing the tip of a blade of a wind power generating set, the installation method includes: cutting off the original tip of the blade of a wind generating set; To the leaf body after the original leaf tip has been amputated.

Preferably, the step of installing the blade tip on the blade body after the original blade tip has been cut off may include: inserting the main beam of the blade tip into the inner cavity of the blade body after the original blade tip has been cut off, so that the main The side of the beam near the front edge and/or the side near the trailing edge is in contact with the side of the web in the inner cavity of the blade body; the side of the main beam in contact with the web is fixedly connected by adhesive ; At least one of the upper and lower surfaces of the main beam is in contact with at least one of the pressure surface and the suction surface of the blade body and bonded.

According to the tip of the blade of the wind power generator set according to the present invention, by setting its winglets to be inclined toward the suction surface or the pressure surface, the flow field characteristics can be used to increase the utilization of the aerodynamic lift component of the winglet part and increase the capture of wind energy. Efficiency; in addition, by setting serrations on the trailing edge, the trailing edge turbulent noise can be reduced.

In addition, the blade tips may be mounted to blades of existing wind turbines, thereby improving the overall efficiency and performance of the existing wind turbines. When the blade tip is installed on the blade body after the original blade tip of the active wind turbine is cut off, through the bonding between the main beam of the blade tip and the web of the blade body, the main beam of the blade tip and the blade body The bonding between the pressure surface and the suction surface can make the accurate positioning between the blade tip and the blade body more accurate, and at the same time, it can increase the connection strength between the blade tip and the blade body, so that the installation quality and installation operation are improved. Controllability has been significantly improved.

Description of drawings

Exemplary embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, and the above and other features and advantages of the present invention will become clearer. In the accompanying drawings:

Fig. 1 is a schematic diagram of a wind turbine blade according to an exemplary embodiment of the present invention;

Fig. 2 is a schematic diagram of a blade tip for a wind turbine blade according to an exemplary embodiment of the present invention;

Fig. 3 is a schematic diagram of a blade tip for a blade of a wind power generating set after the suction surface in Fig. 2 is removed;

Fig. 4 is a partial schematic diagram of installing a blade tip for a blade of a wind power generator set on a blade body after the original blade tip is cut off according to an exemplary embodiment;

5A and FIG. 5B respectively show the effect of a conventional blade tip without winglets on airflow and the effect of a blade tip used for a wind turbine blade according to an exemplary embodiment of the present invention on airflow;

Fig. 6 shows the effect of serrations on the airflow of the trailing edge of the blade tip of a wind turbine blade according to an exemplary embodiment of the present invention.

detailed description

Embodiments of the invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.

A blade tip for a wind power generator blade and a wind power generator blade including the blade tip according to an exemplary embodiment of the present invention will be described below with reference to FIGS. 1 to 3 .

Fig. 1 is a schematic diagram of a wind power generator blade according to an exemplary embodiment of the present invention; Fig. 2 is a schematic diagram of a blade tip 3 for a wind power generator blade according to an exemplary embodiment of the present invention; Fig. 3 is a schematic diagram of Fig. 2 A schematic diagram of a blade tip 3 for a wind turbine blade after removal of the suction face 6 in .

As shown in FIG. 1 , a wind turbine blade according to an exemplary embodiment of the present invention includes a blade root 1, a blade body 2 and a blade tip 3, wherein the blade root 1 is used for mounting the blade on the hub, and the blade body 2 is The blade root 1 extends, and the blade tip 3 is located at the end opposite to the blade root 1 relative to the blade body 2 . The airfoil 2 includes a pressure side and a suction side, and the pressure side and the suction side are connected to each other by bonding of the leading edge and the trailing edge. In an exemplary embodiment according to the present invention, the blade tip 3 may be formed separately from the airfoil 2 and then mounted on the airfoil 2 . However, the present invention is not limited thereto, and the blade tip 3 and the blade body 2 may also be integrally formed by integral molding.

Referring to FIGS. 2 and 3 , a blade tip 3 according to an exemplary embodiment of the present invention may include a main body 31 and a winglet 32 , the main body 31 includes a pressure surface 5 and a suction surface 6 , and the pressure surface 5 and the suction surface 6 are positioned at The leading edge 8 and the trailing edge 9 are connected (bonded) to form the shell of the main body 31 , and the winglet 32 is formed at the end of the main body 31 and is inclined toward the suction surface 6 at a predetermined camber angle α. Here, the predetermined camber angle α may refer to the angle formed between the central axis of the main body 31 and the central axis of the winglet 32 , that is to say, the predetermined camber angle α indicates that the winglet 32 deviates from the main body 31 inclination. For ease of reference, the predetermined camber angle α may be schematically shown by the inclination angle α of the trailing edge of the winglet 32 from the trailing edge of the main body 31 as shown in FIG. 3 . The predetermined camber angle α may be set between about 30° and 80°. Preferably, the predetermined camber angle α may be set to about 40°, about 45° or about 60°. The length of the winglet 32 can be set to about 0.5m to 1.5m, preferably, can be set to about 1m or about 0.8m. According to an exemplary embodiment of the present invention, the winglet 32 may be formed by bending an end portion of the main body 31 toward the suction surface 6 at a predetermined camber angle. The aforementioned pressure surface and suction surface, no matter on the blade body or on the blade tip, can be formed with skins.

Furthermore, the trailing edge 9 of the blade tip 3 may be provided with serrations, which may be formed by cutting the trailing edge 9, or alternatively, the serrations may be formed separately from the blade tip 3 and then mounted on the trailing edge 9 . Here, the serration may comprise a plurality of serrations 91 which may be arranged continuously on the trailing edge 9 . However, the present invention is not limited thereto, and a plurality of serrations 91 may be discontinuously arranged on the trailing edge 9. For example, as shown in FIGS. The sawtooth portion of the sawtooth 91, and no serration is provided on the curved transition portion between the main body 31 and the winglet 32, so that the strength at the curved transition portion can be enhanced.

Wherein, the included angle between adjacent saw teeth 91 among the plurality of saw teeth 91 may be set to about 20° to 60°. According to another exemplary embodiment of the present invention, the included angle between adjacent saw teeth 91 may be set at approximately 30° to 50°. Preferably, the included angle between adjacent saw teeth 91 can be set to about 40°.

The blade tip 3 according to the exemplary embodiment of the present invention may further include a main spar 7 to enhance the strength of the blade tip. The main beam 7 may include a first part disposed inside the casing formed by the pressure surface and the suction surface and a second part extending to the outside of the casing, wherein the first part may be fixedly bonded to the pressure surface 5 and the suction surface by using an adhesive. At least one of the surfaces 6 is arranged inside the shell, and the length of the second part extending to the outside of the shell is between about 0.3m and 1m. Preferably, the length of the second part can be set to about 0.6m. m. Here, if the length of the second part is too short, the main spar 7 cannot provide sufficient auxiliary connection strength when the blade tip 3 is connected to the airfoil 2; if the length of the second part is too long, it may It will affect the connection operation between the main beam 7 and the airfoil 2 .

According to an exemplary embodiment of the present invention, as shown in FIGS. 2 and 3 , the main beam 7 may be configured in a cuboid shape, ie, the ends are rectangular. However, the present invention is not limited thereto, and the main beam 7 may also be arranged in other shapes such as a D-shape, an O-shape, or a C-shape at the end. In addition, the number of main girders 7 can be set to one or more according to actual conditions. In addition, the main girder 7 can also be arranged in the form of a web.

The blade tip 3 according to the exemplary embodiment of the present invention may also include a junction box 12 and an operation hole 13, and the junction box 12 may be arranged on the side of the first part of the main spar 7, so as to facilitate the installation of the blade tip 3 to the airfoil. At 2 o'clock, operations such as the connection of lightning conductors are performed, and the operation hole 13 is sealed with a cover plate after the wiring operation is completed.

The blade tip 3 according to the exemplary embodiment of the present invention may also include a lightning protection and lightning receiving part 10, which is located at the end of the winglet 32, and the lightning receiving and receiving part 10 passes through a lightning protection wire arranged inside the casing 11 is connected to the junction box 12. Here, the lightning arrester 10 may be integrally formed with the winglet 32 . However, the present invention is not limited thereto, and the lightning arrester 10 may also be formed separately from the winglet 32 and then detachably mounted on the winglet 32 for easy replacement. Specifically, the additionally formed lightning arrester 10 may be fixed to the winglet 32 by bolts.

The lightning arrester 10 can be made of aluminum or aluminum alloy. However, the present invention is not limited thereto, and the lightning arrester 10 may also be formed of other conductive materials with strong corrosion resistance.

In addition, the lightning arrester 10 may be provided with drainage holes, so as to avoid damage to the blade caused by opening drainage holes on the suction surface or pressure surface of the blade.

According to another exemplary embodiment of the invention, the winglet 32 of the blade tip 3 may be arranged to be bent towards the pressure face 5 . The blade tip 3 of the winglet 32 according to the other exemplary embodiment is bent towards the pressure surface 5 except that the direction of the winglet 32 is different from the above exemplary embodiment, and other features are similar to the winglet 32. Embodiments that are inclined toward the suction surface 6 are the same or similar, and therefore descriptions of the same or similar features will be omitted here.

In another exemplary embodiment according to the present invention, the winglet 32 is formed at the end of the main body 31 of the blade tip 3 and is inclined towards the pressure surface 5 at a predetermined camber angle α. Here, the predetermined camber angle α may refer to the angle formed between the central axis of the main body 31 and the central axis of the winglet 32 , that is to say, the predetermined camber angle α indicates that the winglet 32 deviates from the main body 31 inclination. The predetermined camber angle α may be set between about 30° and 80°. Preferably, the predetermined camber angle α may be set to about 40°, about 45° or about 60°. The length of the winglet 32 can be set to about 0.5m to 1.5m, preferably, can be set to about 1m or about 0.8m. According to an exemplary embodiment of the present invention, the winglet 32 may be formed by bending an end portion of the main body 31 toward the pressure surface 5 at a predetermined camber angle. The aforementioned pressure surface and suction surface, no matter on the blade body or on the blade tip, can be formed with skins.

Fig. 4 is a partial schematic diagram of installing a blade tip 3 for a blade of a wind power generator set on the blade body 2 after the original blade tip is cut off according to an exemplary embodiment. The method for installing the blade tip 3 of the blade of a wind power generating set according to an exemplary embodiment of the present invention will be described below with reference to FIG. 4 .

According to an exemplary embodiment of the present invention, the installation method of the tip 3 of the blade of the wind power generating set may include: cutting off the original tip of the blade of the wind generating set; The blade tip 3 is installed on the blade body 2 after the original blade tip is cut off.

Specifically, the step of installing the blade tip 3 on the airfoil 2 after the original blade tip has been cut off may include: respectively connecting the pressure surface 5 and the suction surface 6 of the blade tip 3 with the airfoil body after the original blade tip has been cut off. The pressure surface and the suction surface of 2 are aligned and bonded with adhesive glue; after the bonding is completed, glass fibers are used to connect the bonded end faces of blade tip 3 and blade body 2 to strengthen the connection and smooth shape. It should be noted here that during the process of cutting off the original blade tip, attention should be paid to retaining the original lightning conductor so as to be connected to the lightning arrester 10 on the blade tip 3 .

In the case that the blade tip 3 is provided with a main beam 7, the step of installing the blade tip 3 on the blade body 2 after the original blade tip has been cut off may include: inserting the main beam 7 of the blade tip 3 into the original blade tip that has been cut off. In the inner chamber of the airfoil 2 behind the blade tip, make the side of the main beam 7 near the leading edge 8 and/or the side near the trailing edge 9 contact with the side of the web 14 in the inner chamber of the blade air 2; 7 and the contacting side of the web 14 are fixedly connected by adhesive glue; at least one of the upper and lower surfaces of the main beam 7 is in contact with at least one of the pressure surface and the suction surface of the airfoil 2 and glued After the bonding is completed, glass fibers are used to connect the bonded end surfaces of the blade tip 3 and the blade body 2, so as to strengthen the connection and smooth the shape. It should also be noted here that in the process of cutting off the original tip, attention should be paid to retaining the original lightning conductor so as to be connected to the lightning arrester 10 on the tip 3 .

According to an exemplary embodiment of the present invention, through the bonding of the main spar of the blade tip and the web of the blade body, the bonding of the main beam of the blade tip and the pressure surface and suction surface of the blade body, and the pressure surface and suction surface of the blade tip The bonding between the surface and the pressure surface and suction surface of the blade body can make the positioning of the blade tip and the blade body more accurate, the connection strength is stronger, and the installation quality and operation controllability of the blade tip can be improved.

According to an exemplary embodiment of the present invention, by forming a winglet inclined to the suction side or the pressure side at the end of the blade tip, the flow field characteristics can be used to increase the utilization of the winglet part for the aerodynamic lift component, thereby increasing the ability to capture wind energy. efficiency. Fig. 5A and Fig. 5B respectively show the effect of a conventional blade tip 3' without winglets on the airflow and the effect of the blade tip 3 for a wind turbine blade according to an exemplary embodiment of the present invention on the airflow. As shown in 5A, for a conventional blade tip 3' without winglets, the air flow goes around from the pressure surface to the suction surface, forming a vortex on the suction surface, and the air flow has obvious separation phenomenon. As shown in FIG. 5B, since the blade tip 3 for a wind power generator blade according to an exemplary embodiment of the present invention includes winglets inclined towards the suction side, the winglets can block the flow around from the pressure side to the suction side, Weaken the strength of the blade tip vortex so that the airflow does not separate, thereby reducing the induced resistance and improving the aerodynamic efficiency of the wind turbine blades. At the same time, the noise generated by the blade tip vortex can also be reduced. Although there is a risk of moving the tip of the winglet toward the suction side closer to the tower, considering that the actual wind resource data of some wind farms is safer than the design parameters, the safety margin of the blade clearance can be fully utilized to improve the efficiency of blade use. In addition, according to the exemplary embodiment of the present invention, the tip of the blade for a wind power generating set includes a winglet inclined to the pressure surface, which can also block the tip vortex to a certain extent, thereby increasing the efficiency of wind energy capture, Although the additional aerodynamic lift component of a winglet oriented towards the pressure side may not be as large as that of a winglet oriented towards the suction side, it avoids the risk of bringing the blade tip close to the tower.

According to an exemplary embodiment of the present invention, the blade tip of the wind power generating set according to the exemplary embodiment of the present invention can effectively reduce trailing edge turbulence noise by providing the sawtooth portion. Fig. 6 shows the effect of serrations on the airflow of the trailing edge of the blade tip of a wind turbine blade according to an exemplary embodiment of the present invention. Referring to Figure 6, the sawtooth structure of the trailing edge will cause the airflow to form a row of counter-rotating vortex pairs at the trailing edge, change the structure of the wake vortex, reduce the far-field radiation of noise, and reduce the impact of blade aerodynamic noise on the environment.

While the invention has been particularly shown and described with reference to exemplary embodiments of the invention, it should be understood by those skilled in the art that modifications may be made thereto without departing from the spirit and scope of the invention as defined by the claims. Various changes in form and detail.

Claims (14)

1. A blade tip for a wind turbine blade, characterized in that, the blade tip (3) comprises: a main body (31), said main body (31) comprising a pressure surface (5) and a suction surface (6); a winglet (32), the winglet (32) is formed at the end of the main body (31) and is bent towards the suction surface (6) or the pressure surface (5); The main beam (7), the main beam (7) includes a first part arranged inside the casing formed by the pressure surface (5) and the suction surface (6) and a second part extending to the outside of the casing . 2. The blade tip for a blade of a wind power generating set according to claim 1, characterized in that, the trailing edge of the main body (31) and/or the trailing edge of the winglet (32) is provided with serrations. 3. The blade tip for a blade of a wind power generating set according to claim 2, characterized in that, the serration portion comprises a plurality of serrations (91) arranged continuously or intermittently. 4. The blade tip for a wind turbine blade according to claim 3, characterized in that, the included angle between adjacent serrations (91) among the plurality of serrations (91) is between 20° and 60° between. 5. The blade tip for a wind turbine blade according to any one of claims 1-4, characterized in that the winglet (32) faces the The suction surface (6) or said pressure surface (5) is curved. 6. A blade tip for a wind turbine blade according to claim 1, characterized in that said first part is bonded to at least one of said pressure face (5) and said suction face (6) . 7. The blade tip for a wind power generator blade according to claim 1 or 6, characterized in that, the blade tip (3) further comprises: a junction box (12), arranged on the main beam (7) on the side of the first part of the 8. The blade tip for a wind turbine blade according to claim 7, characterized in that, the blade tip (3) further comprises: a lightning arrester (10) located on the side of the winglet (32) At the end, the lightning arrester (10) is connected to the junction box (12) through a lightning conductor (11). 9. The blade tip for a wind turbine blade according to claim 8, characterized in that, the lightning arrester (10) and the winglet (32) are integrally formed; or, the lightning arrester A portion (10) is detachably mounted to said winglet (32). 10. The blade tip for a blade of a wind power generating set according to claim 8, characterized in that, the lightning arrester (10) is provided with drainage holes. 11. The blade tip for a wind turbine blade according to claim 7, characterized in that, the blade tip (3) further comprises: an operation hole (13) formed on the suction surface (6) or the on the pressure side (5). 12. A wind power generator blade, characterized in that the blade comprises a blade root (1), a blade body (2) and a blade tip (3) according to any one of claims 1-11. 13. A method for installing a blade tip of a blade of a wind power generating set, characterized in that the method for installing comprises: Cut off the original tip of the wind turbine blade; Installing the blade tip (3) according to any one of claims 1-11 on the blade body (2) after the original blade tip has been cut off. 14. The installation method according to claim 13, characterized in that the step of installing the blade tip (3) on the blade body (2) after the original blade tip has been cut off comprises: Inserting the main beam (7) of the blade tip (3) into the inner cavity of the airfoil (2) after the original blade tip has been cut off, so that the main beam (7) is close to the leading edge (8) and/or The side near the trailing edge (9) is in contact with the side of the web (14) in the inner cavity of the airfoil (2); The contacting sides of the girder (7) and the web (14) are fixedly connected by adhesive; At least one of the upper and lower surfaces of the main beam (7) is in contact with at least one of the pressure surface and the suction surface of the blade body (2) and bonded.