JP2011027055A - Horizontal wind turbine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a horizontal wind turbine which is simplified in structure, safe in a strong wind, and accurately braked by sensitively responding to the change of the direction of the wind. <P>SOLUTION: This wind turbine includes a rotational speed control mechanism which is installed in a nacelle 3 and which controls the rotational speed of a blade 7 by the centrifugal force. The front portion of the nacelle 3 is swingably supported on a strut 2, and a plurality of rudders 14 extending radially are disposed on the rear portion outer peripheral surface of the nacelle 3. In the strong wind, the front portion of the nacelle 3 is directed toward the wind and maintained by the rudders 14 while the rotational speed of the blade 7 is controlled by the rotational speed control mechanism. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wind turbine, particularly used in a wind power generator. When receiving a high-speed wind, the wind turbine faces upward and the rotational speed of the blade is controlled by centrifugal force so that the rotational speed is kept constant. It relates to a horizontal axis windmill.

  The blade pitch angle in a wind turbine generator using a horizontal axis wind turbine is generally fixed, but in the case of high-speed wind, the wind speed is measured electronically, and the pitch angle of the blade is mechanically changed to reduce the wind pressure against the blade. For example, Patent Document 1 discloses that the load caused by the above is reduced.

JP 2004-353644 A

In the case where the wind speed is measured and the pitch angle of the blade is mechanically changed by computer control based on the measured value, the blade speed is not limited to the above-mentioned Patent Document 1, In many cases, the wind turbine cannot follow its direction, and the wind turbine cannot fully perform its performance.
This is due to a structural problem that mechanical movement cannot immediately follow the instantaneous wind direction change. Especially, if the windmill is large, the mechanical loss is large, and improvement of this point is a big issue. .
SUMMARY OF THE INVENTION An object of the present invention is to provide a horizontal axis wind turbine that is simple in structure, safe in strong winds, and sensitive to changes in wind direction and capable of accurate braking action.

  The specific contents of the present invention are as follows.

(1) In a horizontal axis wind turbine provided with a rotational speed control mechanism for controlling the rotational speed of the blade by centrifugal force inside the nacelle, the front part of the nacelle is supported by the support so as to be able to turn, and the rear outer peripheral surface of the nacelle is The rudder is arranged in a radial direction, and the front of the nacelle is kept upwind by the rudder in a state where the rotation speed of the blade is controlled by the rotation speed control mechanism in a strong wind. Horizontal axis windmill.

(2) The rudder is an abscissa wind turbine according to (1), wherein the rudder has an X shape when viewed from the front, and curved portions that are curved outward are formed at the respective distal ends on the left and right.

(3) The horizontal rudder wind turbine according to (1) or (2), wherein the rudder has a thick front edge and is gradually formed thinner toward the rear edge.

(4) The horizontal axis according to any one of (1) to (3), wherein the rear edge of the rudder is orthogonal to the main axis and has a width at the tip portion wider than the base portion in a side view. Windmill.

  The present invention has the following effects.

In the horizontal axis windmill described in (1) above, since the rudder is mounted on the nacelle, even if the wind direction changes instantaneously, the nacelle also instantaneously follows the direction by the rudder, and winds the front part of the nacelle upwind. Turn to.
When a strong wind blows, the rotational speed measuring machine converts the amount of movement by centrifugal force into rotational speed as the main shaft rotates, and when the rotational speed exceeds a certain level, the rotational speed control mechanism automatically changes the direction of the blade. Thus, the rotation speed decreases.
If the wind direction changes in that state, the front of the nacelle changes the direction of the windward in the windward direction instantaneously by the action of the rudder, so that the blade direction is maintained so that it does not face the wind current, and the blade rotates. However, the speed does not increase and there is no risk of over-rotation. Moreover, since the area of the blade hit by the strong wind is small, there is no possibility that the blade is damaged by the strong wind. When the rotational speed of the main shaft decreases, the direction of the blade is automatically restored by the rotational speed control mechanism and rotates as before.

In the horizontal axis windmill described in (2) above, the rudder has an X shape when viewed from the front in the nacelle. Therefore, the wind flow hit from the side hits the wide side surface of the upper and lower rudder, and the rudder is Since it is formed in the rear part of the nacelle, the front part of the nacelle is easily turned toward the windward with the front support as a fulcrum.
In addition, since each tip portion of the rudder is formed with a curved portion that is curved outward, the airflow hit from the side surface direction of the rudder is suppressed from spreading from the tip portion of the rudder and is excellent in steering performance.

  The horizontal axis wind turbine described in (3) above has a thick plate at the front edge of the rudder and is formed to become thinner gradually toward the rear edge. Since it passes at a high speed, it is less likely to become an obstacle to the blade located behind.

  In the horizontal axis wind turbine described in the above (4), the rear edge of the rudder is orthogonal to the main axis, and in the side view, the tip portion is wider than the base portion. Can react and change direction.

It is a side view of Example 1 of a horizontal axis windmill concerning the present invention. It is a rear view of a horizontal axis windmill similarly. It is the rotation speed control mechanism part enlarged side view of a horizontal axis windmill similarly. FIG. 4 is a sectional view taken along line IV-IV in FIG. 2. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 2. FIG. 3 is a plan view showing a state in which the blade in FIG. 2 has turned. .

  Embodiments of the present invention will be described with reference to the drawings. A front end portion of the nacelle 3 is turnably disposed at an upper end portion of the support column 2 in the horizontal axis wind turbine 1. A variable pitch propeller 5 is attached to the main shaft 4 protruding from the rear end of the nacelle 3.

  The variable pitch propeller 5 has a plurality of (four in the figure) bases of blades 7 mounted on the outer surface of the hub 6 in the radial direction so that the mounting pitch can be changed.

  Inside the nacelle 3, a power generation device 8 connected to the main shaft 4 is disposed. Further, the rotational speed measuring machine 9A and a rotational speed control mechanism 9 including a computer 9D for changing the direction of the blade 6 of the variable pitch propeller 5 according to the measured value are incorporated.

The rotation speed control mechanism 9 for changing the direction of the blade 7 of these variable pitch propellers 5 may be any known one, and an example thereof is shown in FIG.
In FIG. 3, a bevel gear 11 is rotatably disposed on the outer periphery of the bearing 10 in the nacelle 3. A spur gear 12 is fixed to the front side of the bevel gear 11.

A bevel gear 13 is fixed to the base end portion of the blade 7 rotatably supported by the hub 6 and meshed with the bevel gear 11.
In the rotational speed measuring machine 9A, when the sliding body 9B moves in the centrifugal direction due to the centrifugal force accompanying the rotation of the main shaft 4, the movement amount is detected by the proximity sensor 9C and converted into the rotational speed.

  When the proximity sensor 9C measures a predetermined number of revolutions or more, the computer 9D controls the servo motor 9E so that the transmission gear 9F moves backward and meshes with the spur gear 12 on the bearing 10. Rotate with.

  As a result, the bevel gear 13 at the base end of each blade 7 rotates through the bevel gear 11 by 1 to 45 degrees. As a result, the blade 7 facing the front faces sideways and does not receive a strong wind on the front, so that the rotation speed decreases.

  The rotational speed is measured by the amount of movement of the sliding body 9B. When the wind speed decreases and the rotational speed of the blade 7 decreases, the centrifugal force also weakens, so the sliding body 9B returns to its original position. Thereby, the rotational speed of the blade 7 is always controlled by measuring the centrifugal force.

  1 and 2, a plurality of rudders 14 facing the radial direction are mounted on the rear part of the outer peripheral surface of the nacelle 3. The rudder 14 has a trailing edge that is vertical in a side view, and its leading edge is inclined forward as it goes outward in the radial direction, so that the tip width is longer than the width of the base portion.

  As shown in FIG. 4, the cross-sectional shape of the rudder 14 is formed so that the thickness of the front portion is thick and the thickness is gradually reduced toward the rear end. Moreover, as shown in FIG. 2, each front end portion 14A of the rudder 14 is curved outward.

  In FIG. 1, when the airflow indicated by the arrow A hits the blade 7, the airflow is diffused toward the blade tip, but the diffusion is suppressed by the curved portion 7A of the blade tip, and a large amount of airflow is generated at the blade tip having a wide chord length. The rotational force increases.

  When the wind direction changes and the side airflow indicated by the arrow B in FIG. 2 hits the rudder 14, the nacelle 3 is supported by the support 2 at the front, so the blade 7 in FIG. Turn to. When the air flow indicated by the arrow C in the opposite direction is applied to the blade 7, the blade 7 turns rightward with the support column 2 as a fulcrum.

  In this way, even if the wind direction changes, the front surface of the blade 7 always faces upwind. Even in the case of a strong wind during a typhoon, a strong wind hits the front of the blade 7 and the blade 7 rotates at a high speed.

  When a strong wind such as a typhoon blows, the sliding body 9B of the rotational speed measuring machine 9A shown in FIG. 3 moves due to the centrifugal force accompanying the rotation of the main shaft 4, and the amount of movement is measured by the sensor 9C and converted into the rotational speed. Is done.

  When the rotational speed exceeds a certain value, the servo motor 9E is controlled by the computer 9D, the spur gear 9F moves backward, and meshes with the spur gear 12 on the bearing 10 to rotate, thereby turning the blade 7 in the lateral direction. By turning, the transmission gear 9F returns to the original position.

  As a result, the front part of the nacelle 3 faces the windward side, but the blade 7 at the rear part of the nacelle 3 has its front face sideways, so that the rotational speed decreases. Even if the direction of the strong wind changes, the rudder 14 instantly turns the front of the nacelle 3 to the windward, so that the front surface of the blade 7 remains transverse to the wind current and does not over-rotate.

  That is, in the conventional windmill, the direction of the blade 7 can be changed by computer control due to the strong wind. However, since the wind direction changes in an instant, the computer control cannot follow the changed wind direction, and it rotates. However, in the present invention, the front part of the nacelle 3 instantaneously moves upwind against changes in the wind direction. Because it is suitable, there is little risk of damage.

When the wind speed decreases, the rotational speed of the main shaft 4 decreases and the sliding body 9B moves backward. This is detected by the sensor 9C, and the transmission gear 9E rotates reversely under the control of the computer 9D to change the direction of the blade 7 to the original direction. Restore to position.
At the same time, the transmission gear 9 </ b> E moves forward and is disengaged from the spur gear 12 on the bearing 10.

  As shown in FIG. 2, the blade 7 is formed such that the chord length of the blade tip is wider than the chord length of the blade root, and the tip is bent toward the nacelle 3 with the maximum chord length portion 7B as a boundary. 7A is formed. Further, as shown in FIG. 5, the blade thickness of the front edge 7C of the entire blade 7 is increased and gradually decreased toward the rear edge 7D. The same applies to the curved portion 7A.

  Further, the rear edge 7D on the front surface of the blade 7 is inclined in the rear direction. Therefore, when the blade 7 receives the air flow indicated by the arrow A shown in FIG. 5, the front edge 7C is pushed in the direction indicated by the arrow B as a reaction of the air flow moving in the direction of the trailing edge 7D.

  When the blade 7 rotates, the relative flow hitting the blade 7 becomes negative pressure at the front edge 7C portion of the blade 7 due to the Coanda effect, and becomes high pressure in the rear edge 7D region. Therefore, the blade 7 is pushed forward by the difference in atmospheric pressure, and the rotational efficiency is increased.

  As shown in FIG. 6, such a blade 7 with good rotational efficiency is also difficult to rotate when it is oriented sideways with respect to the air flow in the direction indicated by the arrow A. Moreover, even if it rotates, it does not rotate at high speed.

  However, since the rudder 14 follows the wind direction sensitively even at low wind speeds and directs the front of the blade 7 to the windward, the blade 7 always exhibits high rotational efficiency directly facing the airflow, and the power generation effect is enhanced. .

1. Horizontal axis windmill2. Strut 3. Nasser 4. Spindle 5. 5. Variable pitch propeller Hub 7. Blade 7A. Curved portion 8. Power generation device 9. Rotational speed control mechanism 9A. Rotational speed measuring machine 9B. Slider 9C. Proximity sensor 9D. Computer 9E. Servo motor 9F. Transmission gear 10. Bearing 11. Transmission gear 12. Spur gear 13. Bevel gear 14. Rudder 14A. Curved part

Claims (4)

In a wind turbine equipped with a rotation speed control mechanism that controls the rotation speed of the blades by centrifugal force inside the nacelle, the front part of the nacelle is pivotably supported by the support and the radial direction is directed to the rear outer peripheral surface of the nacelle. A plurality of rudder is arranged, and the front part of the nacelle is maintained facing upwind by the rudder while the rotation speed of the blade is controlled by the rotation speed control mechanism in a strong wind. Horizontal axis windmill. 2. The horizontal axis wind turbine according to claim 1, wherein the rudder has an X shape when viewed from the front, and a curved portion that is curved outward is formed at each distal end portion on the left and right. The horizontal rudder wind turbine according to claim 1 or 2, wherein the rudder is formed such that a front edge is thicker and a rear edge is gradually thinner. The horizontal axis wind turbine according to any one of claims 1 to 3, wherein a rear edge of the rudder is orthogonal to the main shaft and has a tip portion wider than a base portion in a side view. .

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