JP5829583B2 - Wind turbine blade, wind turbine and wind power generator - Google Patents

Description

The present invention relates to a wind turbine blade body, a wind turbine, and a wind power generator.

  Wind turbines for wind power generation include a horizontal axis type wind turbine in which a rotation axis is arranged horizontally with the ground and a vertical axis type wind turbine in which a rotation axis is arranged perpendicular to the ground. The vertical axis type windmill is roughly classified into a lift type that rotates the windmill by lift acting on the wing body and a drag type that rotates the windmill by drag acting on the wing body. As a conventional drag type windmill, for example, the one described in Patent Document 1 is known.

JP 2006-46306 A

  Since the conventional drag type windmill has a rotational speed that is proportional to the wind speed, the rotational speed is excessive in a strong wind speed region such as a typhoon, which may cause deformation. Further, in order to avoid such a situation, when the rotational speed of the windmill is suppressed in the entire wind speed region, there is a problem that startability in the weak wind speed region and efficiency in the medium wind speed region are impaired.

The present invention has been made in view of the problems as described above, and can obtain good startability in a low wind speed region and high energy conversion efficiency in a medium wind speed region, and can improve the speed in a high wind speed region. blade body for wind capable of preventing an excessive reduction, and to provide a wind turbine and a wind turbine generator.

In order to achieve the above object, a wind turbine blade according to the first aspect of the present invention includes:
A windmill wing body that travels in the direction of travel in response to drag from the wind and extends straight from one wing tip to the other wing tip,
A first wing surface;
A second blade surface portion forming a back surface of the first blade surface portion;
A stepped portion that protrudes in a direction away from the second blade surface portion from the front end of the first blade surface portion, and has a rear end surface that is formed in a curved shape that is concave with respect to the front side in the traveling direction;
A front edge portion formed in a curved shape that is continuous with the front end of the stepped portion and the front end of the second blade surface portion and is convex toward the traveling direction;
After the rear end of the first wing surface portion and the rear end of the second wing surface portion are formed in an acute angle toward the rear side in the traveling direction and curved toward the second wing surface portion side The edge,
Wherein formed in the first wing surfaces, with a plurality of peaks and projecting in a direction away from said second wing surfaces,
The mountain portion is formed in a saw blade shape and is inclined toward the trailing edge portion side.
And wherein a call.

  The peak portion may be smaller as it is on the rear edge side.

  The path of the wind from the leading edge of the leading edge to the trailing edge of the trailing edge via the first blade surface portion is from the leading edge of the leading edge to the trailing edge portion via the second blade surface portion. It may be longer than the path of the wind to reach the rear end.

The windmill according to the second aspect of the present invention is
A wing body that travels in the direction of travel in response to drag from the wind and extends straight from one wing tip to the other wing tip,
A first wing surface;
A second blade surface portion forming a back surface of the first blade surface portion;
A stepped portion that protrudes in a direction away from the second blade surface portion from the front end of the first blade surface portion, and has a rear end surface that is formed in a curved shape that is concave with respect to the front side in the traveling direction;
A front edge portion formed in a curved shape that is continuous with the front end of the stepped portion and the front end of the second blade surface portion and is convex toward the traveling direction;
After the rear end of the first blade surface portion and the rear end of the second blade surface portion are formed with an acute angle toward the rear side in the traveling direction and curved toward the second blade surface portion side The edge,
A wing body including a plurality of ridges formed on the first wing surface portion and protruding in a direction away from the second wing surface portion, the first wing surface portion facing outward. Features.

A wind turbine generator according to a third aspect of the present invention includes the wind turbine according to the second aspect.

  According to the present invention, good startability in a low wind speed region and high energy conversion efficiency in a medium wind speed region can be obtained, and excessive speed in a high wind speed region can be prevented.

It is a perspective view which shows the wind power generator which concerns on embodiment of this invention. It is a top view which shows a wind power generator. It is a perspective view which shows a wing body. It is sectional drawing which looked at the wing body from the AA direction shown in FIG. It is an enlarged view of the 1st wind receiving part and 2nd wind receiving part of a wing | blade body. It is a figure for demonstrating the lift which acts on a wing body. It is a top view which shows typically a Savonius type | mold windmill. It is a graph which shows transition with time progress of angular velocity of a wind power generator. It is a figure which shows the relationship between the torque of the wind power generator which concerns on embodiment of this invention, and time. It is a figure which shows the relationship between the angular velocity of a Savonius type | mold windmill, and time. It is a figure which shows the relationship between the torque of a Savonius type | mold windmill, and time.

  Hereinafter, the wing body 10, the windmill 20, and the wind power generator 30 which concern on embodiment of this invention are demonstrated in detail with reference to drawings.

  FIG. 1 is an overall perspective view of the wind power generator 30, and FIG. 2 is a plan view of the wind power generator 30 as viewed from above. The wind power generator 30 generates power using the rotational force of the windmill 20 rotated by wind power, and includes the windmill 20, the driving body 31, the generator 32, and the rotary bearing 33.

  The windmill 20 is a so-called vertical axis type windmill, and is arranged on the driving body 31 of the wind power generator 30 so that the rotating shaft 21 is perpendicular to the bottom surface and the ceiling surface of the driving body 31.

  The windmill 20 includes a rotating shaft 21, two rings 22, spokes 23, and three wing bodies 10. The ring 22 is connected to the rotary shaft 21 via three spokes 23 that are elongated round bars extending radially from the rotary shaft 21. The spoke 23 is inserted in a hole (not shown) formed in the wing body 10 and penetrating in the thickness direction of the wing body 10. Each wing body 10 is fixed to the inner surface of the ring 22 with a first wing surface portion 11 (see FIG. 4) described later facing outward. The radius R of the windmill 20 is, for example, 980 mm.

  As shown in FIG. 2, when the wind turbine 20 is viewed from the upper end side of the rotating shaft 21, the three blade bodies 10 all have a front edge portion 13 (see FIG. 4) described later around the axis of the rotating shaft 21. It faces counterclockwise. In addition, although mentioned later in detail, the windmill 20 is comprised so that it may rotate counterclockwise as shown by the white arrow of FIG.

  The body 31 is a rectangular frame made of a steel material such as a square pipe or an angle material. The height of the driving body 31 is, for example, 2800 mm, and the width and depth of the driving body 31 are, for example, 2300 mm.

  Square pipes are arranged in a cross shape at the bottom of the body 31, and a generator 32 is fixed to the upper surface of the intersection. In the ceiling portion of the body 31, square pipes are arranged so as to intersect in an X shape so as to connect the corner portions of the opposing ceiling surfaces, and the rotary bearing 33 is attached to the lower surface of the intersection portion. The rotary bearing 33 rotatably supports the upper end portion of the rotary shaft 21 of the windmill 20. Leg plates are welded to the four corners of the bottom surface of the body 31. The hole formed in the leg plate is for fixing the body 31 to the ground or a structure, and an anchor bolt is driven into this hole.

  The generator 32 includes a stator (not shown) and a rotor (not shown) having a magnetic pole supported rotatably with respect to the stator. The stator is fixed to the bottom surface of the driving body 31, and the rotor is connected to the lower end portion of the rotating shaft 21 of the windmill 20.

  Next, the configuration of the wing body 10 will be described with reference to FIGS. 3 and 4.

  The wing body 10 has a rectangular wing plane shape, and includes a wing end plate 10a, a first wing surface portion 11, a second wing surface portion 12, a front edge portion 13, a rear edge portion 14, and a first wind receiving portion 15. And the 2nd wind receiving part 16 is provided. The distance W between the blade tips of the wing body 10 (the length in the depth direction in FIG. 4) is, for example, 2500 mm, and the length L in the front-rear direction of the wing body 10 (the length in the left-right direction in FIG. 4) is, for example, 723 mm. The thickness T of the wing body 10 (the length in the vertical direction in FIG. 4) is, for example, 120 mm. The wing body 10 is made of, for example, aluminum and has a hollow inside, and a reinforcing material (not shown) is provided therein. The weight of the wing body 10 is, for example, 14 kg.

  The wing body plate 10 a is a flat plate and is provided so as to close both end faces of the wing body 10. The contour shape of the blade end plate 10a is formed in a contour shape in which the cross-sectional shape of the main body of the blade body 10 is expanded outward.

  The front edge portion 13 is formed in a streamlined cross-sectional shape by a curved surface convex toward the outside of the wing body 10, and the curvature of the front end portion is the largest. Further, the length M in the front-rear direction of the front edge portion 13 is formed to be about twice the thickness T of the front edge portion 13, and is formed to be about one quarter of the length L in the front-rear direction of the wing body 10. ing.

  The trailing edge portion 14 is formed in an acute angle shape, and is warped with a constant curvature on the second blade surface portion 12 side so that the first blade surface portion 11 side is convex.

  Between the front edge part 13 and the 1st wing | blade surface part 11, the level | step-difference part which has a curved surface which turns to the front edge part 13 side toward the front edge part 13 side is provided. The curved surface of the step portion functions as a first wind receiving portion 15 that receives a drag force from the wind. The first wind receiving portion 15 is provided in the entire longitudinal direction of the wing body 10, that is, from one wing tip to the other wing tip. The height of the first wind receiving portion 15 (length in the vertical direction in FIG. 4) is slightly smaller than the distance between the first blade surface portion 11 and the second blade surface portion 12.

  The first blade surface portion 11 extends along a chord (a line connecting the front end of the front edge portion 13 and the rear end of the rear edge portion 14) CL, and on the first blade surface portion 11, a blade body is formed. Six sawtooth-shaped six crests 16a arranged in the front-rear direction are formed. The six peak portions 16a are inclined toward the rear edge portion 14, and the height and the length in the front-rear direction of the peak portion 16a are smaller as they are closer to the rear edge portion 14 side. The six mountain parts 16a function as the second wind receiving part 16 that receives a drag from the wind.

  The six peak portions 16a pass through the connecting portion B between the front edge portion 13 and the first wind receiving portion 15, and are formed to be lower than a straight line (two-dot chain line in FIG. 4) in contact with the rear edge portion 14. ing. Thereby, the 2nd wind receiving part 16 receives only the wind blowing from the rear edge part 14 side, and does not receive the wind blowing from the front edge part 13 side.

The total of the wind receiving area of the first wind receiving portion 15 and the wind receiving area of the second wind receiving portion 16 is, for example, 4.9 m ² .

  The second blade surface portion 12 extends along the chord CL, and is formed of a curved surface that is convex toward the outside of the blade body 10.

  Next, the wind flow around the wing body 10 and the lift acting on the wing body 10 will be described. In the following description, the direction from the front edge 13 toward the rear edge 14 is referred to as “forward flow direction”, and the direction from the rear edge 14 toward the front edge 13 is referred to as “reverse flow direction”. As described above, the wind power generator 30 includes the three wing bodies 10. However, for the sake of simplicity, the wind flow around one wing body 10 and the lift acting on the wing body 10 are described. explain.

  FIG. 5 is an enlarged view of the first wind receiving portion 15 and the second wind receiving portion 16 of the wing body 10 arranged along the wind flow direction. As shown in FIG. 5, when wind in the reverse flow direction (shown by a solid line) blows, the wing body 10 hits the first wind receiving portion 15 and the second wind receiving portion 16 and receives drag from the wind. receive. When a drag force in the reverse flow direction acts on the wing body 10, the wing body 10 advances in the reverse flow direction while cutting air at the front edge portion 13. The cut air flows in the forward flow direction on the surface of the wing body 10.

  As shown in FIG. 6, the path of air flowing along the first blade surface portion 11 is slightly longer than the path of air flowing along the second blade surface portion 12. Due to the difference in the travel distance, a lift FL in the direction from the second blade surface portion 12 toward the first blade surface portion 11 (upward in FIG. 6) acts on the blade body 10. The horizontal component Va of the lift FL acts in the reverse flow direction, and its magnitude is larger than the air resistance Ua acting in the forward flow direction. As a result, a propulsive force (= Va−Ua) corresponding to the speed of the wing body 10 is generated. In addition, since the path difference is small, the magnitude of the lift FL acting on the wing body 10 is smaller than the magnitude of the drag.

  In the wind power generator 30 having the above-described configuration, when wind strikes the first wind receiving portion 15 and the second wind receiving portion 16, drag acts on the wing body 10, and the windmill 20 is illustrated with the rotating shaft 21 as the center. Starts rotating counterclockwise of 2. When the rotational speed of the windmill 20 is increased, lift according to the speed of the wing body 10 acts on the wing body 10. The windmill 20 rotates by converting the reaction force acting on the wing body 10 into rotational energy.

  Further, when the windmill 20 rotates, the rotor of the generator 32 integrated with the windmill 20 also rotates, so that the magnetic field between the stator and the rotor changes, and electric power is generated by the principle of electromagnetic induction. The generated electric power is sent to a battery (not shown).

  As described above, according to the wind turbine generator 30 of the present embodiment, the wing body 10 includes the first wind receiving portion 15 and the second wind receiving portion 16, and therefore receives wind in the reverse flow direction. Can receive drag. Thereby, the favorable startability in a weak wind speed area can be obtained.

  Since the wing body 10 includes the second wind receiving portion 16 behind the front edge portion 13, the wind receiving area for the wind in the reverse flow direction can be increased without increasing the projected area. it can. Thereby, the air resistance which acts on the wing body 10 can be suppressed.

  Since the second wind receiving portion 16 is formed in a saw blade shape inclined toward the rear edge portion 14, the second wind receiving portion 16 can reliably catch the wind in the reverse flow direction and receive a larger drag.

  Since the height and width of the peak portion 16a of the second wind receiving portion 16 are smaller toward the rear edge portion 14, the wind can be applied to all the peak portions 16a.

  Since the cross-sectional shape of the leading edge portion 13 is formed in a streamline shape, the generation of turbulent flow around the leading edge portion 13 can be suppressed, and the air resistance acting on the wing body 10 can be suppressed.

  When the wing body 10 moves forward, the lift FL acts on the wing body 10, so that the energy conversion rate in the medium wind speed region can be increased, and the propulsive force acting on the wing body 10 can be increased. Thereby, the rotational speed of the windmill 20 can be increased in the middle wind speed region. However, since the magnitude of the lift FL is smaller than the magnitude of the drag, the rotational speed of the windmill 20 does not become too high. Specifically, the peripheral speed ratio (= speed of the wing body 10 / wind speed) converges to about 1.

  Since the trailing edge portion 14 is warped toward the second blade surface portion 12, when air flows in the forward flow direction, turbulence is generated on the surface of the trailing edge portion 14 on the second blade surface portion 12 side. The generated turbulent flow acts as a resistance acting on the wing body 10 in the forward flow direction. Further, the magnitude of the turbulent flow increases as the moving speed of the wing body 10 increases. The generated turbulent flow generates a resistance force in the forward flow direction and cancels a part of the drag force in the reverse flow direction. Thereby, excessive rotation speed of the windmill 20 in the strong wind speed region can be prevented.

  Next, the characteristics of the wind turbine 20 are compared with the characteristics of the Savonius type wind turbine shown in FIG. 7 while referring to the graphs of FIGS. FIGS. 8 and 10 show the time t (sec) of the angular velocity ω (rad / sec) when the wind turbine 20 and the Savonius type wind turbine in the stopped state are activated by applying a wind in a predetermined medium wind speed range. 9 and 11 are graphs showing changes in the torque T (Nm) acting on the rotary shaft 21 at that time.

  8 to 11, the horizontal axis represents time t, the vertical axis represents angular velocity ω in FIGS. 8 and 10, and the vertical axis represents torque T in FIGS. Each graph has a scale for comparison. The graphs of FIGS. 8 to 11 represent measurement results in a state where the wind turbine 20 is not connected to the generator 32 (no load state).

  As shown in the graph of the wind turbine 20 in FIGS. 8 and 9, the torque T increases when the curve of the angular velocity ω is downwardly convex, and the torque T decreases when the curve of the angular velocity ω is upwardly convex. When the angular velocity ω becomes constant, the torque T becomes zero.

  As shown in the graphs of the Savonius type wind turbine in FIGS. 10 and 11, the torque T decreases in a range where the curve of the torque T is convex upward. When the angular velocity ω becomes constant, the torque T becomes zero.

  As shown in FIGS. 8 and 10, the value (maximum value) at which the angular velocity ω converges is larger for the windmill 20 than for the Savonius type windmill. Thus, the wind turbine 20 has a higher rotational speed than the Savonius wind turbine. That is, the windmill 20 has a higher efficiency for converting energy received from the wind into the rotational energy of the windmill 20 in the middle wind speed range than the Savonius type windmill.

  In addition, the wind power generator 30 of this invention is not limited to embodiment demonstrated. For example, in the embodiment, the material constituting the wing body 10 is aluminum, but it may be a lightweight and high-strength material, and may be another appropriate material, for example, carbon fiber or resin. It does not have to be. In the embodiment, the inside of the wing body 10 is a cavity, but it may not be a cavity.

  In the embodiment, the number of the wing bodies 10 attached to the windmill 20 is 3, but the number is not limited to 3, and may be 2 or 4. In that case, the characteristics of the windmill 20 change according to the number of the wing bodies 10.

DESCRIPTION OF SYMBOLS 10 Wing body 10a Blade end plate 11 1st blade surface part 12 2nd blade surface part 13 Front edge part 14 Rear edge part 15 First wind receiving part 16 Second wind receiving part 16a Mountain part 20 Windmill 21 Rotating shaft 22 Ring 23 Spoke 30 Wind power generator 31 Drive unit 32 Generator

Claims (5)

A windmill wing body that travels in the direction of travel in response to drag from the wind and extends straight from one wing tip to the other wing tip,
A first wing surface;
A second blade surface portion forming a back surface of the first blade surface portion;
A stepped portion that protrudes in a direction away from the second blade surface portion from the front end of the first blade surface portion, and has a rear end surface that is formed in a curved shape that is concave with respect to the front side in the traveling direction;
A front edge portion formed in a curved shape that is continuous with the front end of the stepped portion and the front end of the second blade surface portion and is convex toward the traveling direction;
After the rear end of the first blade surface portion and the rear end of the second blade surface portion are formed with an acute angle toward the rear side in the traveling direction and curved toward the second blade surface portion side The edge,
A plurality of crests formed on the first wing surface portion and projecting away from the second wing surface portion;
The mountain portion is formed in a saw blade shape and is inclined toward the trailing edge portion side.
A wind turbine wing body characterized by the above. The peak portion is smaller as it is on the rear edge side,
The wing body for wind turbines according to claim 1 characterized by things. The path of the wind from the leading edge of the leading edge to the trailing edge of the trailing edge via the first blade surface portion is from the leading edge of the leading edge to the trailing edge portion via the second blade surface portion. Longer than the wind path to reach the rear edge,
The wing body for wind turbines according to claim 1 or 2 . A wing body that travels in the direction of travel in response to drag from the wind and extends straight from one wing tip to the other wing tip,
A first wing surface;
A second blade surface portion forming a back surface of the first blade surface portion;
A stepped portion that protrudes in a direction away from the second blade surface portion from the front end of the first blade surface portion, and has a rear end surface that is formed in a curved shape that is concave with respect to the front side in the traveling direction;
A front edge portion formed in a curved shape that is continuous with the front end of the stepped portion and the front end of the second blade surface portion and is convex toward the traveling direction;
After the rear end of the first blade surface portion and the rear end of the second blade surface portion are formed with an acute angle toward the rear side in the traveling direction and curved toward the second blade surface portion side The edge,
A wing body including a plurality of ridges formed on the first wing surface portion and projecting in a direction away from the second wing surface portion, the first wing surface portion facing outward.
A windmill characterized by that. The windmill according to claim 4 is provided.
Wind power generator characterized by that.

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