JP2006002725A - Windmill with rotary cylindrical body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a windmill with a rotary cylindrical body rotating efficiently at mild wind. <P>SOLUTION: The windmill 10 with the rotary cylindrical body is provided with a cylindrical body 14 rotatably installed on a support shaft 12 and blades 16 attached on the cylindrical body 14 separately in a radial direction and rotating as one unit with the cylindrical body 14. In this case, distance between the cylindrical body 14 and the blade 16 is kept in a range of 0.4r or more and 0.6r or less when radius of the cylindrical body 14 is determined as (r). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wind turbine with a rotating cylindrical body, and more particularly to a wind turbine with a rotating cylindrical body that efficiently rotates at a low wind speed.

  In recent years, clean energy technology development using sunlight, wave power, wind power, etc. has been carried out as alternative energy to replace fossil fuels such as coal and oil. In particular, wind turbines used for wind power generation are roughly divided into horizontal axis types and vertical axis types and are put into practical use. The horizontal axis type includes a horizontal axis propeller wind turbine, a multi-blade type wind turbine, and the like. Particularly, the propeller wind turbine is most frequently used for power generation. The horizontal axis type requires direction control so that the center of the rotation axis faces the wind direction.

On the other hand, in the vertical type, three to five blades (rotary blades) are arranged at equal distances in the radial direction around a vertical thin rotating shaft, and the torque generated by the force of the tangential component of the aerodynamic force acting on the blades There are some which rotate the blade around the rotation axis. Therefore, since the vertical type does not depend on the wind direction like the horizontal axis propeller wind turbine, it can rotate with respect to the wind direction in any direction. As such a vertical windmill, Patent Document 1 discloses a windmill in which a plurality of blades 3 are attached to a rotating body 2. In this windmill, as shown in FIG. 5, a blade-like blade 3 rotates with a rotating body 2 around a thin support shaft 1. By controlling the direction of the blade 3, the number of rotations of the rotating body 2 can be controlled within a specified range and kept constant.
JP 2003-278737 A

The windmill described in Patent Document 1 is rotated by lift generated in the blade 3 by the wind. As a result of extensive research on the vertical wind turbine, the present inventor has found that there is an important relationship that the rotation of the wind turbine affects the distance between the cylindrical body and the blade. However, although the wind turbine for wind power generation according to Patent Document 1 is attached to the thin support shaft 1 and rotated together with the blade 3 formed on the rotating body 2, the distance between the rotating body 2 and the blade 3 is not specified at all. Therefore, sufficient rotation efficiency cannot be obtained. Moreover, a complicated mechanism and power are required for the direction control of the blade 3.
The present invention pays attention to the problems of the prior art described above, and an object of the present invention is to provide a wind turbine with a rotating cylindrical body that has high rotational efficiency and rotates even at low wind speeds.

  According to the wind turbine with a rotating cylindrical body according to the present invention, a cylindrical body that is rotatably mounted on a support shaft, and a blade that is attached to the cylindrical body so as to be spaced apart in the radial direction and rotates integrally with the cylindrical body. And the distance between the cylindrical body and the blade is 0.4r or more and 0.6r or less, where r is the radius of the cylindrical body.

  The wind turbine with a rotating cylinder has a configuration in which the distance between the cylinder and the blade is defined as described above. When the blade hits the wind, lift and thrust are generated on the blade. Further, according to the present invention, the distance between the cylindrical body and the blade is set to 0.4r to 0.6r (r is the radius of the cylindrical body), so that the ground effect is generated by the airflow flowing between the blade and the cylindrical body. . For this reason, the induced drag of the blade is reduced and the lift and thrust are relatively increased. Therefore, the rotation efficiency of the blade is improved, and consequently the energy conversion efficiency is increased. The thrust increases due to the improvement of the lift-drag ratio due to the ground effect, and the windmill can be rotated even at a low wind speed such as 3 m / s to 5 m / s.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a wind turbine with a rotating cylindrical body according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a schematic configuration of a wind turbine with a rotating cylindrical body according to the embodiment. (1) is a figure which shows the side of a windmill with a rotating cylindrical body. (2) shows a sectional view of the side surface of the wind turbine with a rotating cylindrical body. FIG. 2 is a view showing an AA cross section of the wind turbine with a rotating cylindrical body of FIG.

  As shown in FIG. 1, a wind turbine 10 with a rotating cylindrical body basically includes a cylindrical body 14 that rotates around a support shaft 12 and a blade 16 that is formed outside the cylindrical body 14 and that can rotate integrally with the cylindrical body 14. It is configured. The support shaft 12 is a shaft upright in the vertical direction. Further, the support shaft 12 is thicker than the conventional one, and an existing structure such as a utility pole or a chimney can be used. The cylindrical body 14 has a cylindrical shape surrounding the outside of the support shaft 12 and may be made lighter by using, for example, a metal such as aluminum or a plastic resin as a material. A bearing portion 22 is provided between the support shaft 12 and the cylindrical body 14. The bearing portion 22 is formed in a ring shape covering the outside of the support shaft 12 at both ends of the cylindrical portion 14. Thereby, the frictional resistance generated when the cylindrical body 14 rotates around the support shaft 12 can be reduced.

  Flange portions 18 are formed at both ends of the upper and lower openings of the cylindrical body 14. The flange portion 18 is a donut-shaped flat plate and is formed orthogonal to the cylindrical body 14. The flange portion 18 may be made of the same material as the cylindrical body 14 in order to reduce the weight as described above. The flange portion 18 fixes and holds both end portions of a blade 16 to be described later in parallel with the axis of the support shaft 12 at a predetermined interval from the center of the support shaft 12.

  A blade 16 is installed between the upper and lower flange portions 18. As shown in FIG. 2, the blade 16 has a blade shape whose cross-sectional shape reduces air resistance and easily generates thrust, and the blade 16 has a blade width in the vertical direction that is the same as that of the cylindrical body 14. Is formed. In the blade 16, the chord length direction coincides with the tangential direction of the cylindrical body 14. A plurality of 2 to 5 blades 16 can be installed on the outer surface of the cylindrical body 14. In this embodiment, two blades are installed in the diameter direction of the cylindrical body 14. Here, the relationship between the blade 16 installed on the cylindrical body 14 and the cylindrical body 14 depends on the radius of the cylindrical body. In this embodiment, as shown in FIG. 2, when the radius of the cylindrical body 14 is r, the distance a between the cylindrical body 14 and the outer surface of the blade 16 is set to 0.4r to 0 so that a ground effect is generated on the blade 16. .6r is set.

  Further, the wind turbine 10 with the rotating cylindrical body is supported by a stopper 20 attached to the support shaft 12. The stopper 20a is formed in a ring shape having an inner diameter substantially the same as the diameter of the support shaft 12. The stopper 20a is fixed to the support shaft 12 by fixing means such as a bolt. The windmill 10 is inserted from above the support shaft 12 through the inside of the cylindrical body 14, placed on the stopper 20 a, and mounted on the support shaft 12. Further, a stopper 20b is disposed at the upper end of the wind turbine 10 with the rotating cylindrical body to prevent the wind turbine from being displaced. Therefore, the wind turbine 10 with the rotating cylindrical body can be installed at any position in the vertical direction of the support shaft 12 by adjusting the mounting position of the stopper 20. Moreover, after arrange | positioning the fastener 20b in the upper end part of the windmill 10 with a rotation cylinder, the windmill 10 with a rotation cylinder is further inserted from the support shaft 12 upper part. By disposing the stopper 20 at the upper end of the windmill, the windmill 10 with the rotating cylindrical body can be easily mounted in multiple stages in the direction perpendicular to the support shaft 12.

  The wind turbine 10 with a rotating cylindrical body configured as described above operates as described below. The stopper 20a is fixed to an arbitrarily set position of the support shaft 12. Then, the opening of the cylindrical body 14 of the wind turbine 10 with the rotating cylindrical body is inserted from above the support shaft 12, arranged on the stopper 20 a, and attached to the support shaft 12. After mounting the windmill, the stopper 20b is arranged at the upper end of the windmill 10 with the rotating cylindrical body. As a result, the wind turbine 10 with the rotating cylindrical body is detachably attached to the support shaft 12, and the frictional resistance is reduced via the bearing portions 22 at both ends of the cylindrical body 14, so that it can rotate around the axis of the support shaft 12. Become. When the wind turbine 10 with the rotating cylinder is installed in multiple stages in the vertical direction of the support shaft 12, the stopper 20 b is disposed at the upper end of the wind turbine 10 with the rotating cylinder as described above, and then the upper portion of the support shaft 12. It is good to insert the windmill 10 with a rotating cylinder from the top, and arrange | position the stopper 20 in an upper end part.

  The wind turbine 10 with a rotating cylinder generates lift and thrust when wind strikes the blade 16, and the blade 16 rotates integrally with the cylinder 14. In the wind turbine 10 with the rotating cylindrical body, when the radius of the cylindrical body 14 is r, the interval a between the cylindrical body 14 and the blade 16 is set to 0.4r to 0.6r. The ground effect is generated by the air (airflow) flowing between the blades 16 and the induced drag of the blade 16 is reduced. For this reason, the lift force and thrust acting on the blade 16 become relatively large with respect to the drag force, and the rotation efficiency is improved, so that even if the wind speed is about 3 m / s, it can be easily rotated and the energy conversion efficiency can be increased. .

  FIG. 3 is a diagram showing a comparison of power coefficients of the wind turbine with a rotating cylindrical body according to the embodiment. Curve (1) in the figure is a wind turbine with a rotating cylinder according to the present embodiment. When the radius of the cylinder 14 is r, the distance between the cylinder 14 and the blade 16 is 0.4r. Curve (2) is an example in which the cylindrical body is fixed and only the blade rotates around it, and the distance between the fixed cylindrical body and the blade is set to be the same as (1). Curve (3) is a wind turbine with a rotating cylindrical body in which the distance between the cylindrical body and the blade is 0.3r. Also, the horizontal axis in FIG. 3 is the peripheral speed ratio λ, which is the ratio between the tip peripheral speed and the wind speed, and the vertical axis is the power coefficient (Cp). In both cases, the chord length is set to 0.4r, where r is the radius of the cylindrical body 14.

  As shown in the figure, in the case of a wind turbine in which the distance between the cylindrical body of the curve (1) and the blade is 0.4 r, the power coefficient is about 0.3 when the peripheral speed ratio λ is about 2.5. It was. The larger the power coefficient, the greater the rotational efficiency of the windmill and the higher the output. The power coefficient (Cp) of the curve (1) is large because, in addition to the lift generated in the blade itself when the wind hits the wind turbine with the rotating cylinder, the air current between the blade and the cylinder is further influenced by the cylinder. This is because the lift-drag ratio of the blade is improved by the ground effect that changes, and the lift and thrust become relatively large with respect to the drag.

  On the other hand, in the case of the curve (2), the peripheral speed ratio λ is about 1.8 and the power coefficient (Cp) is about 0.07 which is the maximum, but the power coefficient is lowered. This is because the cylindrical body is fixed. If the cylindrical body does not rotate integrally with the blade, the efficiency cannot be expected even if the distance between the cylindrical body and the blade is optimal. In addition, when the distance between the cylindrical body and the blade was 0.7 r or more, the same performance as the curve (2) was exhibited. In the case of the curve (3), the power coefficient was lower than that of the curve (2). This is because the distance between the blade and the cylindrical body is short, and the airflow hitting the blade is not affected by the cylindrical body to generate sufficient thrust, resulting in energy loss due to rotation of the cylindrical body supporting the blade. This is probably due to this.

  In the wind turbine 10 with the rotating cylindrical body of the embodiment, when the distance between the cylindrical body and the blade is 0.5r and the chord length l is 0.8r, the power coefficient is the same as that of the curve (1) described above. The power coefficient is shown, and even when the chord length l is increased, no significant change is seen in the power coefficient. Therefore, it is considered that the ground effect described above affects the distance between the cylindrical body and the blade and does not affect the chord length l.

  As described above, the vertical axis wind turbine with a cylinder according to the present invention improves the lift-drag ratio of the blade by the ground effect in which the airflow between the blade and the cylinder changes due to the influence of the cylinder, for example, 3 m / s to 5 m / Even at a low wind speed such as s, the windmill can be rotated with high efficiency.

  FIG. 4 is a diagram illustrating an installation state of the wind turbine with a rotating cylindrical body according to the embodiment. As shown in the figure, the wind turbine 10 with a rotating cylindrical body is installed in multiple stages in the direction perpendicular to the support shaft 12. Thereby, large electric power can be generated. In addition, a power generation unit 30 that converts driving force into electric power is installed on the support shaft 12 below the wind turbine 10 with a rotating cylindrical body. The power generation unit 30 is configured so that power obtained by the rotation of the wind turbine 10 with a rotating cylindrical body is transmitted to the drive of a generator installed therein to generate power. Moreover, it can install in the existing structures, such as a utility pole and a chimney, by changing the design of the internal diameter of the cylindrical body 14 arbitrarily. Therefore, it is possible to reduce the cost associated with securing the installation location and newly installing the support shaft. Furthermore, since the noise generated when the blade 16 rotates is smaller than that of the propeller, it can be installed in a city area or the like to generate electric power.

It is a figure which shows the structure outline of the windmill with a rotating cylindrical body which concerns on embodiment. It is a figure which shows the cross section of the AA diagram of FIG. It is a figure which shows the comparison of the power coefficient of the windmill with a rotating cylinder which concerns on embodiment. It is a figure which shows the installation state of the windmill with a rotating cylindrical body which concerns on embodiment. It is a figure which shows the structure outline of the conventional vertical axis windmill.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ......... Supporting shaft, 2 ......... Rotating body, 3 ......... Blade, 10 ......... Windmill with rotating cylindrical body, 12 ...... Supporting shaft, 14 ......... Cylinder, 16 ......... Blade, 18 ......... Flange part, 20 ......... Stopper, 22 ......... Bearing part, 30 ......... Power generation unit.

Claims (1)

A cylindrical body rotatably mounted on a support shaft, and a blade that is attached to the cylindrical body and spaced apart in the radial direction and rotates integrally with the cylindrical body, where r is the radius of the cylindrical body And a distance between the cylindrical body and the blade is 0.4 r or more and 0.6 r or less.

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