WO2012073321A1

WO2012073321A1 - Vertical shaft windmill

Info

Publication number: WO2012073321A1
Application number: PCT/JP2010/071336
Authority: WO
Inventors: 健杉崎
Original assignee: 株式会社Cno
Priority date: 2010-11-30
Filing date: 2010-11-30
Publication date: 2012-06-07
Also published as: JPWO2012073321A1

Abstract

[Problem] Conventional vertical shaft windmills struggled to obtain good rotation starting properties, because drag operated more strongly than lift force in low wind regions. The purpose of the present invention is to provide a vertical shaft windmill capable of efficient rotation even in low wind regions. [Solution] In order to solve said issue, the present invention provides a vertical shaft windmill comprising a cylindrical rotating shaft and a plurality of blades supported by the cylindrical rotating shaft via a blade supporting arm. The interval between the blades and the cylindrical rotating shaft is at or below the length of the blades in the vertical direction.

Description

Vertical axis windmill

The present invention relates to a vertical axis type windmill used for wind power generation and the like.

As a windmill, a horizontal axis type windmill having a horizontal rotation axis and a vertical axis type windmill having a vertical rotation axis are known. Unlike the horizontal axis type wind turbine, the vertical axis type wind turbine has an advantage that it can be used as a rotational drive source for wind from either direction of 360 degrees and can be arranged in a compact space.

As a vertical axis type wind turbine, one having a structure in which a plurality of blades are installed on a circumference around a thin rotating shaft is generally known. For example, Patent Document 1 discloses a technique for improving the aerodynamic characteristics of a blade by adjusting the blade thickness of a vertical axis wind turbine to improve the rotation efficiency.

JP 2009-191744 A

However, in the conventional vertical axis type windmill, the drag acts more strongly than the lift force in the slight wind speed region, so it is difficult to obtain high rotational startability. Therefore, an object of the present invention is to propose a vertical axis type windmill that can be efficiently rotated even in a low wind speed region.

In order to solve the above-mentioned problems, the present invention is a vertical axis wind turbine comprising a cylindrical rotating shaft and a plurality of blades supported by a blade rotating arm on the cylindrical rotating shaft. A vertical axis wind turbine is proposed in which the interval between the cylindrical rotating shafts is substantially the same as the diameter of the cylindrical rotating shaft.

In the present invention, since the force (inductive drag) that drags the blade toward the trailing edge is weakened and the ratio of lift to the drag is increased, the blade can be efficiently rotated even in the low wind speed region.

The top view which shows an example of the shape of the vertical axis type windmill of Embodiment 1. The front view which shows an example of the shape of the vertical axis type windmill of Embodiment 1. 1 is a side view showing an example of the structure of a vertical axis wind turbine according to a first embodiment. The top view which shows an example of the structure of the vertical axis type windmill of Embodiment 1. The figure which shows the mode of the induction drag which acts on the blade of the conventional vertical axis type windmill The figure which shows the mode of the induced drag which acts on the blade | wing of the vertical axis type windmill of Embodiment 1. The figure which shows the lift and the drag which act on the wing | blade of the vertical axis type windmill of Embodiment 1. The front view which shows an example of the shape of the vertical axis type windmill of Embodiment 2. The side view which shows an example of the structure of the vertical axis type windmill of Embodiment 2. The side view which shows an example of the structure of the vertical axis type windmill of Embodiment 3. The side view which shows the other example of the structure of the vertical axis type windmill of Embodiment 3. The figure which shows the relationship between the electric power generation amount of the vertical axis type windmill of Example 1, and a wind speed.

Hereinafter, embodiments of the present invention will be described. The correspondence between the claims and the embodiment is as follows. The first embodiment mainly relates to claims 1 to 5, the second embodiment mainly relates to claims 6 and 7, and the third embodiment mainly relates to claim 9. In addition, this invention is not limited to the example of the following embodiment, It is possible to implement in various aspects.

<< Embodiment 1 >>

<Overview>
The vertical axis wind turbine according to the present embodiment is characterized in that the distance between the blade and the cylindrical rotating shaft is equal to or less than the length of the blade in the vertical direction. With this configuration, the force that drags the wing toward the trailing edge (inductive drag) decreases, and the ratio of lift to drag increases, so that the rotational startability of the wing increases.

<Configuration>
1 and 2 are a plan view and a front view showing an example of the shape of the vertical axis wind turbine according to the present embodiment. As shown in these drawings, the “vertical shaft type windmill” of the present embodiment is supported by the “cylindrical rotating shaft” 1 and the “cylindrical rotating shaft” by the “wing support arm” 2. And a plurality of “wings” 3.

The “cylindrical rotating shaft” 1 has a function as a rotating shaft of the wing and a function of receiving air blowing from the horizontal direction on its side surface to form an airflow around the shaft. Furthermore, it plays a role as a surface facing the “lower surface of the blade” 31 and has a function of increasing the pressure of the airflow between the blade and the cylindrical rotating shaft.

It is preferable that the diameter of the cylindrical rotating shaft is substantially the same as the “chord chord length” 32 in order to sufficiently fulfill the role of the surface facing the cylindrical rotating shaft. If the diameter of the cylindrical rotating shaft is made smaller than the chord length, the function as the surface facing the lower surface of the wing will be reduced, and if it is made too large, the size and weight of the cylindrical rotating shaft will become larger than necessary. turn into. In the present specification, “substantially the same” means that the difference between the values of one and the other is within ± 20% of the magnitude of the smaller one or the other.

Similarly, it is preferable that the vertical length of the cylindrical rotating shaft and the vertical length of the blade are substantially the same in order for the cylindrical rotating shaft to sufficiently fulfill the role of the surface facing the lower surface of the blade. When the vertical length of the cylindrical rotating shaft is shortened compared to the vertical length of the wing, the function as the facing surface is reduced, and the vertical length of the cylindrical rotating shaft is reduced to the vertical length of the wing. If it is longer than that, the size and weight of the cylindrical rotating shaft will be larger than necessary.

3 and 4 are a side view and a plan view showing an example of the internal structure of the vertical axis wind turbine according to the present embodiment. As shown in FIG. 3, the “cylindrical rotating shaft” includes a “post member” 11, a “connecting member” 12 that connects the post member and the wing support arm member, and a “cylindrical cover” for covering the post member and the like. The structure which consists of "member" 13 etc. can be considered. The cylindrical cover member is provided with an “arm extraction hole” 14 through which the member of the wing support arm passes.

Here, high strength materials such as stainless steel and carbon fiber are used for the strut members, and durable and lightweight materials such as metal such as aluminum, carbon fiber, and plastic resin are used for the connecting member and the cylindrical cover member. Is preferably used. In addition, it is also conceivable to use a lightweight plastic material that is easy to process, such as an acrylic resin or an ABS resin, for a portion of the cylindrical cover member that does not require strength.

The “wing support arm” 2 has a function of connecting the blade and the cylindrical rotating shaft and transmitting the rotational force of the blade to the cylindrical rotating shaft. For example, as shown in FIGS. 3 and 4, the “wing support arm” includes two “arm members” 21 </ b> A and 21 </ b> B connected to a cylindrical rotating shaft, and a pair of “arm cover members” covering the arm members. A configuration including 22A, 22B, and the like is conceivable.

Here, it is preferable to use a highly durable and lightweight material such as aluminum or carbon fiber for the arm member. For the arm cover member, it is preferable to use a lightweight plastic material that is easy to process, such as acrylic resin or ABS resin.

Further, by setting the “interval between the blade and the cylindrical rotating shaft” 41 to be “the length of the blade in the vertical direction” 33 or less, as described below, the force (inductive drag) that drags the blade toward the trailing edge is reduced. It becomes possible.

FIG. 5 is a diagram showing a state of induced drag acting on the blades in a conventional general vertical axis type wind turbine. In the conventional vertical axis type wind turbine, from the viewpoint of increasing the rotational force, the “interval between the blade and the rotary shaft” 40 is made relatively large, and the diameter of the rotary shaft is made as small as the strength allows. In such a case, the pressure at the distance between the blade and the rotating shaft is slightly higher than the upper surface of the blade, but not so high. For this reason, the “inclination of airflow (down angle)” 26 increases from the upper surface side to the lower surface side of the blade at the trailing edge of the blade. Here, since the induced drag acting on the wing increases as the blowing angle increases, a relatively large “induced drag” 27 is generated on the wing.

FIG. 6 is a diagram showing a state of induced drag acting on the wing when the distance between the wing and the cylindrical rotating shaft is equal to or less than the vertical length of the wing. When the “interval between the blade and the cylindrical rotating shaft” 41 is equal to or less than the length in the vertical direction, the pressure at the interval between the blade and the cylindrical rotating shaft is higher than that of the conventional vertical axis type wind turbine. Therefore, the “airflow inclination (down angle)” 26 from the upper surface side to the lower surface side of the blade at the trailing edge of the blade is relatively small. Since the induced drag acting on the wing becomes weaker as the blow-down angle is smaller, the “induced drag” 27 acting on the wing decreases as the blow-down angle decreases. That is, it is possible to reduce the induced drag acting on the blade by making the rotation shaft cylindrical and setting the distance between the blade and the cylindrical rotation shaft to be equal to or less than the vertical length of the blade.

It should be noted that when the distance between the blade and the cylindrical rotating shaft is not more than half the vertical length of the blade, it is preferable in that the induced drag acting on the blade is particularly reduced. However, if the distance between the blade and the cylindrical rotating shaft is too narrow, the rotational torque will be reduced. Therefore, the distance between the blade and the cylindrical rotating shaft is about 25 to 35% of the vertical length of the blade. It is preferable.

Also, the “average horizontal width of the wing support arm” 42 is preferably 30% or more of the diameter of the cylindrical rotating shaft from the viewpoint of rectifying the air flowing on the side surface of the wing support arm in the horizontal direction. From the viewpoint of lightness, the blade support arm is preferably less than 50% of the diameter of the cylindrical rotating shaft. Further, by making the arm cover member a curved surface as shown in FIGS. 2 and 3, the flow of the airflow can be made smooth.

It is also preferable to provide a hole in any position of the blade support arm to ensure a vertical flow path. With this configuration, since the flow path is secured in the vertical direction even when the blade support arm is rotated, air can smoothly enter and exit from the inside of the circumferential locus of the blade. Specifically, as shown in FIG. 4, two “arm members” 21 </ b> A and 21 </ b> B are arranged at a predetermined interval, and the “arm member” is arranged at the approximate center of the region from the wing to the cylindrical rotating shaft. It is conceivable that the

arm cover members

22A and 22B are not covered. As a result, a “hole” 23 serving as a vertical flow path is formed in the approximate center of the region from the blade to the cylindrical rotation axis.

2 and 3 show the configuration in which the wing is supported by the wing support arm at one central position in the vertical direction. However, the wing support arm may be configured to support the wing at two upper and lower positions. There is also a configuration in which the support is provided at more points. Various support points are also conceivable.

“Wings” 3 has a function of generating torque in the rotational direction by lift. Here, it is preferable to use a lightweight and high-strength material such as fiber reinforced plastic or carbon fiber for the wing. Moreover, it is preferable that a some wing | blade is supported at equal intervals in a rotation direction from a viewpoint of generating a torque equally irrespective of the direction where the wind of a horizontal direction blows.

As shown in FIG. 4, the “wing upper surface” 30 is gently curved from the leading edge to the trailing edge, and the “wing lower surface” 31 is planar from the leading edge to the trailing edge. The leading edge portion of the wing has a rounded shape, and the trailing edge portion has a sharp shape. These features are similar to the main wing of an airplane. The blade thickness is preferably 5 to 30% of the diameter of the cylindrical rotating shaft at the thickest portion from the viewpoint of generating high lift.

FIG. 7 is a diagram showing the force acting on the wing when a horizontal wind blows. As shown in this figure, the “wing” 3 generates “lift” 52 by receiving “wind from the horizontal direction” 51. The lift acts in a direction perpendicular to “drag” 53 acting on the wing, and has a component of “rotation direction” 54. The blade rotates using the component in the rotation direction as a drive source. Here, the “force for dragging the blade toward the trailing edge (inductive drag)” 27 is reduced by setting the distance between the blade and the cylindrical rotating shaft to be equal to or less than the vertical length of the blade as described above. For this reason, in the vertical axis type windmill of this embodiment, the ratio of the lift to the drag is increased, and a larger rotational force can be obtained.

<Effect>
In the vertical axis wind turbine of the present embodiment, the force (inductive drag) that drags the blade toward the trailing edge is reduced, and the ratio of lift to the drag is increased. Therefore, the blade can be efficiently rotated even in the low wind speed region. It becomes possible.

<< Embodiment 2 >>

<Overview>
In addition to the features of the first embodiment, the vertical axis wind turbine according to the present embodiment supports the wings at two upper and lower positions so that the rectification surrounded by the wing support arms, the cylindrical rotating shaft, and the wings A window is formed. Since the air that has entered the inside of the wing's circumferential trajectory is compressed by the rectifying window, the induced drag acting on the wing is further reduced, and the ratio of lift to drag is increased. It becomes possible to do.

<Configuration>
FIG. 8 is a front view showing an example of the shape of the vertical axis wind turbine of the present embodiment. The basic configuration is the same as that of the first embodiment, but the vertical axis type wind turbine of the present embodiment supports the “wings” 3 by the “wing support arms” 2A and 2B at two upper and lower positions. A “rectifying window” 4 surrounded by the “wing support arms” 2A and 2B, the “cylindrical rotating shaft” 1 and the “wing” 3 is formed.

The “rectifying window” has a function of adjusting the flow velocity and direction of the air flowing into the space between the blade support arm, the cylindrical rotating shaft, and the blade. Since the air flowing into the rectifying window is compressed, the induced drag acting on the wing is further reduced. Therefore, in the vertical axis type windmill of this embodiment, the ratio of lift to drag is further increased, and higher rotational efficiency can be obtained even in the slight wind speed region.

FIG. 9 is a side view showing an example of the structure of the vertical axis wind turbine of the present embodiment. As shown in this figure, when the “wing support arm” is composed of two “arm members” 21A and 21B (21C and 21D) and “arm cover members” 22A and 22B (22C and 22D), the arm cover member Is a hyperboloid, and when the rectifying window is viewed from the front, it may be substantially zero-shaped. Note that the arm cover member may have a curved shape such as a truncated cone or a hemispherical surface.

In order to increase the effect of rectification, the horizontal width of the blade support arm is preferably 30% or more of the length of the blade in the rotation direction. Note that even if it is 50% or more, the effect of rectification is not greatly affected, so 30 to 50% is preferable from the viewpoint of weight reduction.

Also, the distance between the upper and lower wing support arms is preferably 50% or more of the vertical length of the wing. By enlarging the area of the rectifying window to some extent, it becomes possible to rectify (compress) a predetermined amount or more of air in the horizontal direction.

In addition, it is particularly preferable that the distance between the blade and the cylindrical rotating shaft is approximately half of the distance between the upper and lower blade support arms. Since the distance is less than half the vertical length of the wing, the force acting on the trailing edge of the wing (inductive drag) can be reduced sufficiently, and between the wing and the cylindrical rotating shaft. Since there is a certain interval, a relatively large rotational torque can be generated.

<Effect>
In the vertical axis wind turbine of the present embodiment, since the induction drag is further reduced as compared with the vertical axis wind turbine of the first embodiment, it is possible to obtain higher rotational efficiency even in the low wind speed region. .

<< Embodiment 3 >>

The vertical axis wind turbine according to the present embodiment is characterized in that in addition to the configuration of the first or second embodiment, a generator sharing a shaft with a cylindrical rotating shaft is provided. With this configuration, the rotation of the cylindrical rotation shaft can be directly transmitted to the generator, and power generation can be performed efficiently.

<Configuration>
FIG. 10 is a diagram illustrating an example of the structure of the vertical axis wind turbine according to the present embodiment. The basic configuration is the same as in the first or second embodiment, but the vertical axis wind turbine of the present embodiment has a “generator” 5 that shares a “cylindrical rotating shaft” 1 and an “axis” 11. It is characterized by.

“The“ generator ”has a function of converting the rotation of the cylindrical rotating shaft into electric power. Since the generator of this embodiment shares a shaft with the cylindrical rotating shaft, the rotating force of the cylindrical rotating shaft can be directly used, and power generation can be performed efficiently. As a specific example of the generator, for example, a permanent magnet type AC generator may be used. The electric power generated by the generator is taken out by wiring not shown. It is conceivable that the electric power is consumed by an electric device such as a lighting fixture or a battery is charged.

FIG. 11 is a diagram showing another example of the structure of the vertical axis wind turbine of the present embodiment. The generator can be arranged inside the cylindrical rotating shaft as shown in FIG. 10. However, for example, when the shape of the generator is large and cannot be arranged inside the cylindrical rotating shaft, FIG. As shown, it is possible to adopt a configuration in which it is arranged below the cylindrical rotating shaft. Moreover, the structure which arrange | positions a generator above a cylindrical rotating shaft is also possible.

It is also possible to configure a low-rotation high-output wind power generator by disposing a gear, pulley, etc. that share the shaft with the cylindrical rotation shaft and providing a generator that is connected to the transmission. is there.

Also, a configuration in which the generator is controlled by a controller installed inside or outside the vertical axis wind turbine is possible. For example, when it is desired to control the rotation speed within a constant speed range, it is conceivable to apply an electric brake or accelerate using the power of a battery connected to the generator.

<Effect>
In addition to the effects of the first embodiment, the vertical axis wind turbine of the present embodiment can directly transmit the rotation of the cylindrical rotary shaft to the generator, so that it is possible to efficiently generate power.

The vertical axis wind turbine of the present embodiment includes a cylindrical rotating shaft, a blade supporting arm that supports the blade at two upper and lower positions, three blades supported at equal intervals in the rotation direction, and a cylindrical rotating shaft. And a generator that shares the shaft and is arranged inside the cylindrical rotating shaft. The shape of the vertical axis wind turbine of this embodiment is the same as the example shown in FIGS. 7 and 8, and the structure is the same as the example shown in FIG.

The cylindrical rotating shaft is composed of a support member, a connecting member that connects the support member and the wing support arm, and a hollow cylindrical cover member that covers the support member and the like. Here, the support member is made of stainless steel, and the connecting member and the cylindrical cover member are made of aluminum. The upper and lower portions of the cylindrical cover member are acrylic resin dome. The diameter of the cylindrical cover member is the same as the chord length of the wing, and the vertical length of the cylindrical cover member including the dome is 115% of the vertical length of the wing. The chord length is 0.30 [m], and the vertical length of the wing is 1 [m].

In the vertical axis wind turbine according to the present embodiment, there are six blade support arms in total because the three blades are supported at two locations, upper and lower. Each wing support arm is composed of two arm members arranged with a gap and a pair of arm cover members. The arm member is an aluminum material, and the arm cover member is an acrylic resin material. The distance from the cylindrical cover member to the wing is 30% of the vertical length of the wing. Further, the average horizontal width of the wing support arms (average horizontal width of the arm cover member) is 40% of the diameter of the cylindrical cover member. Further, the arm cover member is a hyperboloid, and the rectifying window surrounded by the arm cover member, the cylindrical cover member, and the wings has a substantially zero shape when viewed from the horizontal direction.

The upper surface of the wing has a gently curved shape from the leading edge to the trailing edge, and the lower surface of the wing has a planar shape from the leading edge to the trailing edge. The leading edge portion of the wing has a rounded shape, and the trailing edge portion has a sharp shape. The diameter of the circumferential trajectory of the wing is the same as the vertical length of the wing. The thickest part of the wing is 5% of the vertical length of the wing. The weight of each wing is 3 [kg].

The generator is a permanent magnet type three-phase AC generator, which is arranged inside a cylindrical rotating shaft. Here, the body of the generator and the wing support arm are connected by an aluminum connecting member.

FIG. 12 is a diagram showing the relationship between the power generation amount and the wind speed of the vertical axis wind turbine of this example. As shown in this figure, the vertical axis wind turbine of this example generates 11 [W] of power at a wind speed of 4 [m / s] and 305 [W] of power at a wind speed of 12 [m / s]. It is possible to generate electricity. In other words, it was possible to efficiently generate power even in the low wind speed region.

DESCRIPTION OF SYMBOLS 1 ... Cylindrical rotating shaft, 2 ... Blade support arm, 3 ... Blade, 4 ... Rectification window, 5 ... Generator, 11 ... Strut member, 12 ... Connecting member, 13 ... Cylindrical cover member, 14 ... Arm extraction hole, 21A D: Arm member, 22A to D: Arm cover member, 23: Hole, 26: Blow down angle, 27: Inductive drag, 30 ... Upper surface of wing, 31 ... Lower surface of wing, 32 ... Length of chord, 33 ... Vertical length of the wing, 40 ... spacing between the wing and the rotating shaft (conventional technology), 41 ... spacing between the wing and the cylindrical rotating shaft, 42 ... horizontal width of the wing support arm, 51 ... horizontal wind, 52 ... Lift acting on the wing, 53 ... Drag acting on the wing, 54 ... Direction of rotation of the wing

Claims

A cylindrical rotation axis;
A plurality of wings supported by a wing support arm on a cylindrical rotating shaft;
A vertical axis type windmill consisting of
A vertical axis wind turbine in which a distance between the blade and the cylindrical rotating shaft is equal to or less than a length in a vertical direction of the blade.
The vertical axis wind turbine according to claim 1, wherein a distance between the blade and the cylindrical rotating shaft is equal to or less than a half of a vertical length of the blade.
The vertical axis wind turbine according to claim 1 or 2, wherein a diameter of the cylindrical rotating shaft is substantially the same as a chord length of the blade.
The vertical axis wind turbine according to any one of claims 1 to 3, wherein a vertical length of the cylindrical rotating shaft is substantially the same as a vertical length of the blade.
The vertical axis wind turbine according to any one of claims 1 to 4, wherein a horizontal width of the blade support arm is 30 to 50% of a length in a rotation direction of the blade.
The vertical direction according to any one of claims 1 to 5, wherein a rectifying window surrounded by the wing support arm, the cylindrical rotating shaft, and the wing is formed by the wing support arm supporting the wing at two upper and lower positions. Axial wind turbine.
The vertical axis wind turbine according to claim 6, wherein a distance between the blade and the cylindrical rotating shaft is substantially half of a distance between the blade support arms at the two upper and lower portions.
The vertical axis wind turbine according to any one of claims 1 to 7, further comprising a generator sharing an axis with the cylindrical rotating shaft.