JP2007285289A - Reverse direction-half rotation blade perpendicular shaft type windmill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make blades "reverse direction-half rotation blades" to make both of lift and drag generated on the blade most effectively act on rotation of a rotor at any position and design blade area large although it is believed that using lift at high speed rotation is a condition to show high performance and slim and flow line shape blade to keep drag generated on the blade as small as possible are used for most of present windmills. <P>SOLUTION: This windmill is a windmill having a shaft perpendicular to flow of wind as represented by a straight Darrieus wind turbine. A bearing allowing rotation of the blade itself is provided on an edge support part of a plurality of blades provided in parallel with the rotary shaft and with keeping equal distances. Each blade rotates by half (1/2) of rotation of the rotor when the same rotates around a rotor (windmill main body) center shaft by one rotation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an anti-semi-rotary blade wind turbine.

  Modern windmills are considered to be conditions for high-speed, high-efficiency windmills, such as propeller-type windmills and darume windmills, to become high-performance windmills. And the relative speed of the blades of a large windmill may exceed 100 meters per second.

  However, no matter how fast the windmill is rotated, there is a limit value of Betz, and there are also problems of increased loss and noise caused by high speed rotation. Further, although the lift generated on the blade is proportional to the square of the relative speed, the direction of the generated force is greatly deviated from the rotation direction, so that the effective rotating force is reduced to a fraction. At this time, the blade itself is loaded with the total lift generated, and the strength of the blade needs to be designed to be quite high. Furthermore, the high-speed type windmill is designed to have a small blade area in order to reduce the resistance caused by the drag generated on the blades, and in reality the start-up performance and operation performance during low winds are poor.

  A wind turbine whose axis is perpendicular to the wind flow, as represented by a straight Darius wind turbine, and a bearing that allows the blade itself to rotate on each support part of multiple blades (blades) installed parallel to the rotation axis and equidistant. A type characterized by a blade that rotates half (1/2) in the opposite direction to the rotation of the rotor when each blade rotates once around the center axis of the rotor (wind turbine body). The windmill.

  Due to the heavy use of fossil fuels, global warming and air pollution have been promoted, and various disasters have been caused by environmental destruction, abnormal weather, etc. Currently, the development of clean natural energy utilization is an urgent need worldwide. . The spread of solar power generation is the most advanced in Japan in the world, but the development of wind energy utilization has been delayed due to low energy density and difficulty in handling. Constructed on the coast, on the sea, on hills and mountain peaks from windmills that can stably extract small energy from refreshing breeze and large energy from strong winds, and small windmills that can be easily installed on the roofs of buildings and rooftops of buildings The present invention is effective in the development of a popular wind turbine that can be installed in places where the location is relaxed, even in large-scale wind turbines.

1 is straight. It is for making it easy to understand the image of the windmill of the present invention while comparing with the Darius windmill.
In this invention, the surface area of the blade of the wind turbine is designed to be large, and the lift and drag generated in the blade are controlled as the rotational force of the wind turbine by controlling the angle of the blade when the wind turbine is at each position with respect to the wind flow. It is a low-speed type windmill that aims to draw out effectively.

FIG. 2 is a cross-sectional view of the wind turbine, and the wing A.V. B. C. D shows the heading angle at each position. The lift La acts at point A, the drag Db at point B, and the lift Lc at point C, respectively, in the direction of the arrow to generate torque. At point D, the angle of attack of the wing against the wind is 0 degrees, so no force is generated.
In FIG. 2, Po is a pulley installed on the central axis of the windmill, Pe is a pulley attached to the blade, and the diameter of Pe is twice the diameter of Po, and both are connected by a belt or a chain. Instead of a belt or a chain, an odd number of gears may be used for connection. (In this case, Pe / Po uses a gear with a gear ratio of 2 to 1.) ・ When the blade rotates 90 degrees by the torque La generated at point A and moves to point B, the blade rotates 45 degrees to the left. This is for explaining that the angle of attack shown in (3) is obtained. When the wind direction is changed, the angle of attack of the blade against the wind flow can be kept as shown in the figure (tracking) by rotating the Po arrow in the direction of the wind.

Moreover, this windmill can be considered as both a vertical axis type and a horizontal axis type with respect to the ground surface (horizontal) surface, and has respective features.
The correspondence when the wind direction changes is mentioned earlier. This is an effective yaw control device for the vertical axis type. In FIG. 2, yaw control is possible by turning the gear or pulley Po attached to the center axis of the windmill in accordance with the change in the wind direction in a cross section as seen from the top (or bottom) of the windmill. The vertical axis type is easy to install on the roof or the roof of a building and is suitable for relatively small ones.
The horizontal axis type is a cross-sectional view as seen from the side with B as the top and D as the bottom in FIG. 2. In this case, the change in the wind direction is the horizontal direction, and the change in the vertical direction of the wind flowing along the ground surface is The Po attached to the central shaft is fixed, and it is necessary to control the entire wind turbine so that the rotational axis of the wind turbine is perpendicular to the wind flow and the A side is upwind. Therefore, the horizontal axis type yaw control requires a large device for rotating the entire wind turbine. Looking at the angle of attack of this type of wing against the wind, the higher the torque, the easier it is to obtain a stronger torque. Generally, the higher the wind speed is, the better the wind turbine is. As wind turbine installation locations in the future, coastal or offshore can be considered, but when installing on the water, the entire wind turbine is installed on the float and anchored to a solid pile etc., so it operates as a downwind type wind turbine, There is no need for a large yaw control device. In addition, this theory can also be applied by means such as providing a rectifying plate that also serves as a tail on both sides of a windmill on the leeward side from the center of the rotating shaft when installed on the ground.

Next, I would like to describe the control of the angle of attack for the wing wind flow.
(Control method 1)
In this wind turbine, when the rotor rotates once, the blades rotate half (1/2) counterclockwise. However, when the control is performed with the 2 to 1 diameter or gear ratio described in the explanation of FIG. 2, the rotor always rotates. Rotate in the opposite direction at half the speed.
FIG. 3 is a diagram for explaining another angle of attack control.
(Control method 2)
From point E to point F in FIG. 3 (1/4 turn), the blade is rotated in the opposite direction at the same speed as the rotation of the rotor. In the ¼ turn from the point F to the point G, the wing is fixed to the rotating shaft of the wing. The quarter turn from point G to point H rotates the blade in the opposite direction at the same speed as the rotor. The wings are fixed to the shaft for ¼ turn from point H to point E.
When controlled in this way, the angle of attack of the wing is a right angle (90 degrees) between E and F, and parallel (0 degrees) between G and H. Further, the angle between F and G rotates from 90 degrees to 90 degrees from parallel (0 degrees), and the distance between H and E rotates from 90 degrees to parallel (0 degrees) to 90 degrees, respectively, and the rotor rotates once (360). The wings make a half turn (180 degrees) in the opposite direction. In this attack angle control, 100% drag is used between E and F, the effect of some lift is discarded between G and H, the drag acting in the negative direction of rotation is set to 0, and between F and G and between H and H Between E, lift is mainly used. As described above, there are two methods for controlling the blades to make a half rotation during one round of the rotor, and they can be selectively used for designing a wind turbine utilizing the respective features and advantages.

  Next, the idea about the wing is described. The idea of the windmill according to the present invention began by efficiently converting the force acting on the sail of a yacht or sailing ship that captures the wind and sprints with a large wind to a rotational force. Therefore, it is desirable that the wind receiving area of the wing be large (when the slim wing is used, the number of wings is large), and the shape that efficiently generates both drag and lift. A solid symmetrical wing type using strong and relatively lightweight materials such as aluminum and FRP can be considered first, but it is light and flexible because it is a low speed type with less load on the wing than the high speed type. Sail-like wings and lift using materials. The future challenge is to develop a wing that is curved to generate drag more efficiently.

  In the case of gusty winds or strong winds exceeding the rated output, a device that temporarily accumulates energy in a flywheel or the like and releases the energy when the wind weakens is an effective means because it is a low speed type. When a strong wind exceeding that continues, output control can be performed by shifting the arrow direction of the Po wind direction described in the section of yaw control from the wind direction (horizontal direction in the horizontal axis type).

  Sectional drawing of a straight Darius windmill and the windmill of this invention.   Sectional drawing of a windmill. The angle of attack of the wing at each position of the wind turbine and the force (arrow) generated there are shown for the wind flow.   Explanatory drawing of the anti-half-rotary blade control method.

Explanation of symbols

O is the central axis of the windmill.
A, B, C, D, and E indicate positions from the point O with respect to the wind flow.

Claims (1)

  A wind turbine whose axis is perpendicular to the wind flow, as represented by a straight Darius wind turbine, and a bearing that allows the blade itself to rotate on each support part of a plurality of blades (blades) installed in parallel and equidistant to the rotation axis. The wind turbine is characterized in that when each wing rotates once around the central axis of the rotor (wind turbine body), it rotates while rotating half (1/2) in the opposite direction to the rotation of the rotor.

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