JPH09100774A - Blade for wind power generator - Google Patents

Abstract

(57) Abstract: A blade capable of increasing the amount of power generation of a wind turbine generator is provided. SOLUTION: A current plate is attached to a required portion of the back surface of a blade main body 12 so as to extend in the chord length direction.
The flow B ′ of the wind in the span direction generated by the centrifugal force during the rotation of the blade I is blocked by the flow straightening plate, and the blade main body 1
The influence on the flow A of the wind in the chord length direction from the front edge 12a to the rear edge 12b is reduced. The separation of wind from the middle of the chord length direction is suppressed, the lift of the blade I is improved, and the rotation torque is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade used in a wind turbine generator that rotates blades by wind force to generate electric power.

[0002]

2. Description of the Related Art In the development of new energy and natural energy, there is wind power generation that converts wind energy into electric energy. Wind power has attracted attention as a clean energy source, and is widely used in places with low energy, such as offshore structures and remote islands.

In the wind power generator used for the wind power generation, as shown in the outline of an example in FIG. 4, the nacelle 2 is supported on the upper end portion of the tower 1 so as to be horizontally rotatable, and the inside of the nacelle 2 is supported. The tip of the rotating shaft 3 rotatably supported by
By projecting forward from the nacelle 2 and integrally attaching a theta hub 5 having a set of two blades 4 coaxially attached to the tip end portion of the rotary shaft 3 through a theta pin 6,
Rotational power is transmitted to the rotating shaft 3 via the theta hub 5 by rotating the blade 4 by wind force, and the speed increasing device 7 and the generator 8 installed in the nacelle 2 are connected to the rotating shaft 3 of the rotating shaft 3. Connected to the rear end, the power transmitted to the rotary shaft 3 is increased by the speed increasing device 7 and transmitted to the generator 8,
It is made to generate electricity. Reference numeral 9 denotes a pitch angle operation unit provided at the tip of the rotary shaft 3 so that the pitch angle of the blade 4 can be changed by the cylinder 10 connected to the root of the blade 4.

[0004]

However, as for the blade 4 of the above-mentioned conventionally used wind power generator, as shown on the back surface side of the blade 4 in FIG. A flow A in the chordal length direction from the leading edge 4a to the trailing edge 4b is formed, but at this time, the root portion 4 of the blade 4 is generated by the centrifugal force generated by the rotation of the blade 4.
Since a strong wind flow B in the span direction (longitudinal direction) from the c side to the tip 4d is generated, the flow A in the chord length direction is carried to the flow B in the span direction and deflected.
In a region that is deflected by about a degree or more (a region surrounded by a broken line), a phenomenon occurs in which the wind flow A does not follow the blade surface and is separated from the middle in the chord length direction. In particular, this tendency remarkably appears in the intermediate region except both ends in the span direction. When the wind separation phenomenon occurs, a vacuum is generated in that portion, so that turbulent flow occurs and the lift force is reduced. As a result, the rotational torque of the blade 4 is reduced, and the electrical energy based on the rotation of the blade 4 is reduced. There is a problem that you will not get as planned.

Therefore, the present invention provides a blade for a wind turbine generator capable of increasing the amount of power generation by suppressing the wind separation phenomenon on the back surface side and improving the lift to increase the rotational torque. Is what you are trying to do.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a weir for a wind flow in a span direction due to a centrifugal force when the blade body rotates at a required portion on the back surface of the blade body for a wind turbine generator. The current plate for stopping is attached so as to extend in the chord length direction.

The flow of the wind in the span direction generated on the back surface side of the blade body by the centrifugal force when the blade body rotates is
It will be blocked by the straightening vane, so that the flow of wind in the chord length direction will not be largely changed, and the separation phenomenon of wind flowing along the chord length direction will be suppressed,
The lift of the blade is improved and the rotational torque is increased.

Further, when the current plate has an arc shape, the shape resistance can be further reduced.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

1 (a) and 1 (b) show an embodiment of the present invention. As with the one shown in FIG. 3, two blades 4 attached to a rotary shaft 3 are rotated to generate electricity. In the wind power generator that is configured to perform the conventional blade 4
The blade I is used instead of. That is, the blade I of the present invention is designed so that the flow B ′ of the wind in the span direction due to the centrifugal force during rotation is blocked in the middle of the blade I, so that the blade body 12 has its back surface extending from the axis 0 of the rotary shaft 3 to the tip of the blade body 12. 1/4 and 1 / of the length L up to 12d, respectively
A plate 11 serving as a straightening plate extending in the chord length direction is attached to the position 2 so as to have a height that slightly protrudes from the back surface of the blade body 12 in a small projection shape.
It should be noted that FIGS. 1A and 1B show only one blade body 12. Also, for convenience, the blade body 1
2 is represented as a flat plate having no twist.

When the blade I is rotated by wind force,
The wind that comes into contact with the back surface side of the blade I becomes a chord length direction flow A along the back surface from the front edge 12a to the rear edge 12b of the blade body 12. At this time, due to the centrifugal force due to the rotation of the blade I, a spanwise wind flow B ′ from the root portion 12c side of the blade body 12 toward the tip 12d is generated. The blade 11 is blocked by the plate 11 extending in the chord length direction which is attached to the back surface of the blade body 12 in the middle of the span direction, and escapes rearward. That is, the plate 11
Is mounted at positions of L / 4 and L / 2 from the axis 0 of the rotary shaft 3, so that the spanwise wind flow B ', which is about to be accelerated in the intermediate region of the blade body 12 in the span direction, is effective. Can be suppressed. Therefore, the wind flow B ′ in the span direction is the wind flow B in the span direction shown in FIG.
The wind flow A in the chord length direction can be rectified without largely changing the direction.

Therefore, the wind A flowing in the chord length direction is not separated from the back surface of the blade and follows the entire surface thereof. As a result, the lift of the blade I can be improved and the rotational torque is increased. Therefore, the amount of power generation can be increased by the amount of increase in the rotation torque. Since the plate 11 has a height slightly protruding from the back surface of the blade body 12, the shape resistance of the blade body 12 during rotation is extremely smaller than the increase in the rotational torque.

Next, FIG. 2 shows another embodiment of the present invention. The chord length attached to the back surface of the blade body 12 in the same construction as that shown in FIGS. 1 (a) and 1 (b). The plate 11 extending in the direction is formed into an arc shape having a radius centered on the axis 0 of the rotary shaft 3.

The configuration shown in FIG. 2 is more advantageous than the configuration shown in FIG. 1 because the shape resistance of the plate 11 during the rotation of the blade body 12 can be made smaller.

It should be noted that the mounting location and the number of mounting of the plate 11 are not limited to the above-mentioned embodiment,
Further, the plate 11 can be attached to the blade main body 12 regardless of whether it is a new product or an existing product. Further, in the embodiment, the case where the wind power generator having two blades is adopted is shown. Needless to say, it can be similarly applied to a wind turbine generator having one or more blades, and various changes can be made without departing from the scope of the present invention.

[0016]

Next, the results of experiments conducted by the present inventors will be described.

FIG. 3 shows the experimental results. The vertical axis is the torque, the horizontal axis is the forward constant obtained by dividing the rotational speed of the blade by the rotational speed multiplied by the diameter of the wind turbine with the blade, and the curve X is shown. The blade I of the present invention is shown, and Y is shown for the conventional blade 4.

As is apparent from FIG. 3, in the case of the blade I of the present invention, the negative torque is large, and accordingly a large amount of generated power is obtained.

[0019]

As described above, according to the blade for a wind power generator of the present invention, since the straightening plate extending in the chord length direction is projected and attached to a required portion on the back surface of the blade body, the blade is rotated. The flow of the wind in the span direction generated by the centrifugal force can be blocked by the straightening vanes, and the flow of the wind in the chord length direction can be rectified without being significantly changed. By suppressing the separation phenomenon of the wind flowing in the direction, it is possible to improve the lift of the blade and increase the rotational torque, and therefore, it is possible to increase the amount of power generation with a simple configuration, Further, by forming the straightening plate in an arc shape having a radius centered on the rotation axis of the blade body, it is possible to reduce the shape resistance of the straightening plate, which is an excellent effect. Exhibit.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a blade for a wind turbine generator of the present invention, in which (a) is a rear view and (b) is a side view.

FIG. 2 is a back view of a blade showing another embodiment of the present invention.

FIG. 3 is a graph showing the results of experiments on the relationship between torque and forward constant performed using the blade of the present invention and the conventional blade.

FIG. 4 is a schematic perspective view showing an example of a wind turbine generator.

FIG. 5 is a schematic diagram showing a situation of wind flow acting on a conventional blade used in a wind turbine generator.

[Explanation of symbols]

 11 plate (rectifying plate) 12 blade body 0 axis center

Claims (2)

[Claims] 1. A rectifying plate for blocking a wind flow in a span direction due to a centrifugal force when the blade body rotates is attached to a required portion on the back surface of the blade body for a wind turbine so as to extend in the chord length direction. A blade for a wind turbine generator characterized in that 2. The blade for a wind turbine generator according to claim 1, wherein the current plate has an arc shape with a radius centered on the rotation axis of the blade body.