JP4322845B2 - Tapered Savonius vertical axis wind turbine, gyromill vertical axis wind turbine and wind power generator using it - Google Patents

Description

  The present invention relates to a Savonius vertical axis wind turbine having a wind receiving surface tapered in the vertical direction, a gyromill vertical axis wind turbine, and a wind power generator using the same.

  The Savonius windmill is known for its characteristic of starting to rotate even in light winds. A conventional Savonius windmill rotates by receiving wind from the side with a wind receiving surface of a style in which two or more arc-shaped blades are stacked in steps. However, while it has the feature that it starts to rotate even with a light wind, it has an aspect in which the output efficiency in a strong wind is bad, and various improvements have been tried to use this high energy wind with a high wind speed.

  In order to improve the output efficiency, an invention in which the shape of the inner surface and the outer surface of the blade is different is known (see, for example, Patent Document 1 and Patent Document 2), and a twist type in which the blade is twisted The Savonius windmill is manufactured by Windside (Finland).

  In addition, performance studies based on differences in the shape of the Savonius wind turbine have been made, and behavioral analysis of the airflow around the blade is known (Non-Patent Document 1). Based on the results of previous research, the performance of the Savonius wind turbine in terms of the difference in the shape of the Savonius wind turbine is the same as that of the Bach type, when comparing the Savonius wind turbine with three shapes, semicircular (with overlap) and semicircular (no overlap). It is most efficient, then semicircular (with overlap) and semicircular (no overlap).

  In Non-Patent Document 1, conventionally, the most efficient of the Bach type was considered to be because it is easier to obtain torque because the portion where the moment is applied is outside the semicircular type. However, from the analysis of the air flow around the blade, it is pointed out that the Bach type has a straight portion of the bucket on the return side from its shape, so there is more air flow flowing into the wind receiving bucket than the semicircular type. ing. In the case of a semi-circular shape, the torque of the return side bucket tends to block the flow of the airflow that is about to flow into the wind receiving bucket (due to the resistance during the return movement), and the efficiency is reduced. It is pointed out that it gets worse.

As described above, the conventional Savonius windmill has a blade having a shape in which two or more arc-shaped blades are stacked in steps, but the vertical direction (longitudinal direction) of the blade is a linear shape. The area is the same regardless of the top or bottom cross section.
On the other hand, the wind has a difference in wind speed in the height direction (vertical direction) from the ground, and generally the upper wind speed is high, and of course the energy is large.
In the conventional Savonius wind turbine, the wind in the high wind speed region where the upper energy is large is received by a cross section having a small wind receiving area, while the return motion is performed with respect to the energy obtained from the wind in the low wind velocity region where the lower energy is small. The resistance at the time increased, and the output of the windmill could not be increased.

Japanese Patent Publication No. 8-93627 JP 2003-293928 A Proc. 22nd Wind Energy Symposium “Performance Evaluation by Visualizing Internal Flow of Vertical Axis Wind Turbine”

  In the conventional Savonius windmill described above, the efficiency is improved for uniform wind speed, but it is insufficient for the actual wind with a difference in wind speed, and especially the energy of the upper high speed wind and the lower low speed wind can be absorbed well. The output decreased.

  In addition, since the windmill itself is heavy, there is a problem that the resistance to the bearing is large and the turbulence of the airflow around the blade due to the downwind wind becomes a resistance, and there is a demand for a windmill with good wind receiving efficiency according to the actual wind It was.

The Savonius vertical axis wind turbine according to the present invention aims to further improve the output efficiency of the wind turbine, and can use wind with high energy and high wind speed, and in the region where the wind speed is low, the resistance by wind during return movement is reduced. Let's make it a subject.
An object of the present invention is to provide a gyromill vertical axis wind turbine having high output efficiency, and to provide a wind power generator in combination with the Savonius vertical axis wind turbine according to the present invention.

As a result of producing and improving various prototypes, the present inventors have completed the Savonius vertical axis wind turbine according to the present invention.
The Savonius vertical axis windmill according to the present invention uses wind of high energy and high wind speed, and reduces wind resistance during the return motion in a low wind speed region, so that the windmill blades are vertically moved (vertical direction). The blade was tapered so as to give a difference in cross-sectional area. In general, since the upper wind speed is high, the taper shape of the wind turbine blade is set so that the upper wind receiving sectional area is increased and the lower wind receiving sectional area is decreased. If the wind speed difference is upside down (the upper wind speed is low and the lower wind speed is high), the taper shape of the wind turbine blade is made larger on the lower wind receiving cross section, and the upper wind receiving cross section is increased. Make it smaller.
The Savonius vertical axis wind turbine according to the present invention is structurally configured to perform a movement to obtain energy by the wind and a return movement to rotate against the wind while the blade rotates once.

The first aspect of the present invention is characterized in that the pair of wind-receiving face bodies 1 have a taper shape in the vertical direction, have a lift generation splitter 13, and are formed in a blade cross-section thick streamline. A Savonius vertical axis wind turbine is provided.
Since the pair of wind-receiving face bodies 1 have a vertically tapered shape, they can cope with winds having a difference in wind speed between the upper and lower sides, and can absorb the energy of high-speed wind and low-speed wind and increase the output. That is, by making the taper shape, a difference in cross-sectional area can be given in the vertical direction (longitudinal direction) of the blade.
Also, the lift generation splitter is provided to reinforce the blades and to reduce the bearing load by lifting force due to the rising airflow and to reduce the torque at the time of startup.

Here, preferably, the Savonius vertical axis windmill according to the first aspect of the present invention includes a structure that twists or shifts in the vertical direction of the blade, or a structure that generates shift and twist.
By providing twisting and shifting in the vertical direction of the blade, it is possible to cope with any wind direction and to generate a flow toward the wind receiving face body.

Moreover, it is preferable that the wind-receiving surface body 1 consists of a carbon material FRP blade.
By using a carbon FRP blade, the blade can be made light and sturdy, and can withstand gusts and strong winds. Also, the windmill itself can be reduced in weight and the bearing load can be reduced.

From the second aspect of the present invention, the chord length of the wind turbine blade of the gyromill vertical axis wind turbine is designed so that the ratio of the blade length to the rotation circumference (solidity) is 0.18 to 0.20. A gyromill vertical axis wind turbine is provided. Here, the thickness of the wind turbine blade is preferably designed so that the blade thickness ratio of the wind turbine blade is 0.2. This is because the wind turbine efficiency can be maximized.
Moreover, it is preferable that the curvature of the blades of the wind turbine blade is designed to be 5%. The starting force can be obtained even in the low wind speed region, and the rotation performance in the low rotation region is taken into consideration.

  According to a third aspect of the present invention, a Savonius wind turbine is axially coupled to a gyro mill vertical axis wind turbine via a shaft mechanism (clutch), and is axially coupled using the output of the Savonius vertical axis wind turbine. There is provided a wind turbine generator that assists in starting an axial wind turbine and increases the power generation output by transmitting the shaft rotation to the generator by reversing the direction of the shaft rotation.

The Savonius wind turbine uses the area effect and has a characteristic that the start efficiency is good and a large torque is generated even in a light wind, but the output efficiency of the wind turbine is low. On the other hand, the gyromill vertical axis wind turbine uses blade lift, and the start-up performance of the wind turbine is low. However, since the lift can be used, the output efficiency of the wind turbine is high. By connecting the Savonius wind turbine and the gyromill vertical axis wind turbine with a shaft mechanism (clutch), the hybrid wind turbine can be rotated even at a low wind speed and can be a wind power generator with high output efficiency. By utilizing the characteristics of each windmill, the power generation efficiency of the wind turbine generator is improved.
Further, by using the tapered Savonius vertical axis wind turbine according to the present invention, which can be expected to improve operating efficiency and power generation efficiency, a wind power generator capable of rotating at a low wind speed and having high output efficiency is realized.

Here, the shaft mechanism (clutch) that connects the Savonius wind turbine and the gyromill vertical axis wind turbine has an axis mechanism that assists the initial rotation of the gyromill vertical axis wind turbine and cuts the rotation assistance when the rotational speed increases. It is preferable. When the gyromill vertical axis wind turbine rotates at a steady speed, it is assumed that the axis rotation of the Savonius wind turbine is faster and the shaft rotation of the Savonius wind turbine becomes a load. It is a thing.
The starting force of the Savonius wind turbine is transmitted to a lift type wind turbine such as a gyromill vertical axis wind turbine or Darius vertical axis wind turbine through a shaft mechanism (clutch) placed in the middle, and the lift type wind turbine has obtained a constant rotational force. By the way, the Savonius windmill is cut off.

  In the Savonius vertical axis wind turbine according to the present invention, the pair of wind-receiving face bodies 1 have a vertically tapered shape, have a lift generation splitter 13, and are formed in a blade cross-section thick streamline. In response to wind with wind, the energy of high speed wind and low speed wind can be absorbed well and the output can be increased. In other words, it is possible to use wind with high energy and high wind speed, and in the region where the wind speed is low, there is an effect of reducing resistance caused by wind during the return movement.

  Further, by connecting the Savonius vertical axis wind turbine according to the present invention and a gyromill vertical axis wind turbine having excellent output efficiency by a shaft mechanism (clutch), a hybrid combined wind turbine can be rotated even at a low wind speed and wind power generation having high output efficiency. Equipment can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  Hereinafter, an embodiment of a Savonius vertical axis wind turbine according to the present invention will be described in detail with reference to FIGS. FIG. 1 is a front view of a Savonius vertical axis wind turbine according to the present invention. FIG. 2 shows a cross-sectional view (a) and an external view (b) from the side of one of the wind receiving face bodies of the Savonius vertical axis wind turbine according to the present invention. In particular, FIG. 2 (a) shows the cross-section of the wind receiving face, with the position of the lower end (A in FIG. 2), the position 1/3 of the height (B in FIG. 2), and 2/3 of the height. 4 (C of FIG. 2) and the position of the upper end (D of FIG. 2), the cross-sectional shape and the arrangement viewed from directly above are shown.

In the front view of FIG. 1, reference numeral 1 denotes a pair of wind receiving surfaces, the upper surface is wide, the lower surface is narrow, and the overall shape is an inverted taper shape, which is displaced vertically and twisted 180 degrees spirally. ing. That is, the wind receiving surface body 1 is provided with a half turn around the turning center of the windmill. This can be understood from FIG. 2 (a) sectional view and (b) side view.
FIG. 2 (a) focuses on one of the pair of wind-receiving face bodies 1, and the position (A) of the lower end, the position 1/3 of the height (B), and the height shown in FIG. The cross-sectional shape of the wind receiving face body is shown at four locations, 2/3 position (C) and upper end position (D). The A cross section is at the lower end, the B cross section is at 1/3 of the height, the C cross section is at 2/3 of the height, and the D cross section is at the upper end. It can be understood that the cross-sectional shape from the A cross section to the D cross section is similarly increased, and is arranged so as to make a half turn around the turning center of the windmill from the lower end to the upper end. This twisting of the wind receiving surface body 1 brings about the effect of smooth rotation and less noise such as wind noise.

  Two stages of a lift generation splitter 13 and a lift generation splitter 14 are provided midway in the vertical direction of the wind receiving surface body 1. Reference numeral 2 denotes an upper end plate, and 3 denotes a lower end plate. The upper surface 11 and the lower surface 12 of the pair of wind receiving surface bodies 1 are sandwiched and integrated.

  Reference numeral 4 denotes a bearing which supports the weight of the Savonius vertical axis wind turbine and is rotatable. The lift generation splitters 13 and 14 generate lift during rotation to reduce the load on the bearing.

  The wind receiving surface body 1 is formed in a blade cross section thick streamline, and the air flow around the blade is improved by the wind together with the lift generating splitters 13 and 14. It is made of FRP made of carbon material, and is lightweight and sturdy and thick.

  Next, FIG. 3 shows an external view of the wind turbine generator according to the present invention. In the present embodiment, a composite wind turbine of a Savonius vertical axis wind turbine and a gyromill vertical axis wind turbine is used.

  Reference numeral 5 denotes a clutch that transmits or cuts off the rotation of the shaft. 6 is a double-sided twin-rotor generator that generates electricity by rotating a Savonius vertical axis wind turbine. Reference numeral 7 denotes a gyromill vertical axis wind turbine. 8 is an auxiliary solar cell, and 9 is a support frame.

  In the vertical axis wind turbine device having the above-described structure, the upper half of the inverted tapered twist wind receiving body 1 receives the upper high-speed wind and the lower half receives the lower low-speed wind. The lift generating splitters 13 and 14 reduce the weight of the windmill itself by turning and lighten the load on the bearing 4. The Savonius vertical axis windmill that is easy to start even with a slight wind improves the power generation efficiency by turning the gyromill vertical axis windmill 7 that is difficult to start via the clutch 5 and the generator 6.

  When the gyromill vertical axis wind turbine starts to rotate at a high speed, the clutch 5 is disengaged to make the rotation of the Savonius wind turbine free, and power is generated only by the gyromill vertical axis wind turbine.

  Here, the chord length of the wind turbine blade of the gyromill vertical axis wind turbine is preferably designed so that the solidity σ = 0.18. The solidity σ represents the ratio of the blade length to the rotation circumference, and if the rotation radius and the number of blades are determined, the chord length can be determined so that σ = 0.18. FIG. 5 is a graph showing the relationship between the wind turbine efficiency and the peripheral speed ratio, using the solidity σ of the wind turbine blades of the gyromill vertical axis wind turbine as a parameter. The graph of FIG. 5 is based on the experimental results of lift / efficiency characteristics of the wings actually performed by the inventors.

  The thickness of the wind turbine blade of the gyromill vertical axis wind turbine is preferably designed such that the blade thickness ratio β = 0.2 (20%) of the wind turbine blade. Since the blade thickness ratio β of the wind turbine blade represents the ratio of the chord length to the blade thickness, if the chord length is determined, the blade thickness can be determined so that β = 0.2. FIG. 6 is a graph showing the relationship between the wind turbine efficiency and the peripheral speed ratio with the blade thickness ratio β of the wind turbine blade of the gyromill vertical axis wind turbine as a parameter. The graph in FIG. 6 is based on the experimental results of the lift / efficiency characteristics of the blades actually performed by the inventor. According to the graph, the maximum efficiency is obtained at the blade thickness ratio β = 0.2 (20%). Can be understood.

  Further, the blade warp of the wind turbine blade of the gyromill vertical axis wind turbine is preferably a blade with a warpage of 5% with good rotational performance in a low rotation region. The blade warp λ = 0 (0%) shows the highest efficiency, but the blade with 0% warp has little starting force and is not suitable for the low wind speed region. This is because a blade with a 5% warpage and good rotation performance in a low rotation range is preferable although it is reduced. FIG. 7 is a graph showing the relationship between the wind turbine efficiency and the peripheral speed ratio, using the blade warp λ of the wind turbine blade of the gyromill vertical axis wind turbine as a parameter. From the graph of FIG. 7, it can be seen that the maximum efficiency is shown at blade warp λ = 0 (0%), but it can be understood that the blade with 0% warp has little starting force and is not suitable for low wind speed regions. .

4A and 4B show the shape of the second embodiment of the present invention, and the reverse-tapered wind receiving surface body 1 of the second embodiment is not twisted and is straight.
The upper surface 11 is wide and easy to receive wind, and the lower surface 12 is narrow as in the above embodiment. However, since there is no twist in the vertical direction of the blade, the shape is easy to understand.

  As shown in FIG. 4B, there is a deviation between the larger upper end surface 110 and the smaller lower end surface 120 of the wind receiving surface body 1 toward the turning center side of the windmill, and the diameter of the upper end plate 2 is The diameter of the lower end plate 3 is large and small. The lift generation splitters 13 and 14 are provided in two stages in the vertical direction as in the above-described embodiment, and generate an upward force during turning to reduce the load on the bearing 4. It is preferable that the lift generation splitters 13 and 14 have a horizontal or elevation angle with respect to the turning direction of the windmill.

  The Savonius vertical axis wind turbine having such a structure can absorb wind energy having a difference in wind speed in the vertical direction, and can obtain smooth rotation.

  The Savonius vertical axis windmill according to the present invention has good operating efficiency, is small and has low noise, and can be used as a private power generation system in low-rise and high-rise buildings. In addition, it has high power generation efficiency and is useful as a power generation system for outdoor lights such as outdoor lights and power generation systems for highways and bridges.

The front view of the Savonius vertical axis windmill which concerns on Example 1 of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a cross-sectional view (a) and an external view (b) of a side surface of one wind receiving face body of a Savonius vertical axis wind turbine according to a first embodiment of the present invention. It is an external view of the wind power generator concerning the present invention. The external appearance shape of Example 2 of this invention is shown, (a) is a front view, (b) It is a top view. It is a graph showing the relationship between the wind turbine efficiency and the peripheral speed ratio using the solidity σ of the wind turbine blade of the gyromill vertical axis wind turbine as a parameter. It is a graph showing the relationship between the wind turbine efficiency and the peripheral speed ratio with the blade thickness ratio β of the wind turbine blade of the gyromill vertical axis wind turbine as a parameter. It is a graph showing the relationship between the wind turbine efficiency and the peripheral speed ratio with the blade warp λ of the wind turbine blade of the gyromill vertical axis wind turbine as a parameter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wind receiving surface body 2 Upper end plate 3 Lower end plate 4 Bearing 5 Shaft mechanism (clutch)
6 Double-sided twin rotor generator 7 Gyromill vertical axis windmill 8 Auxiliary solar cell 9 Support frame 11 Upper surface 12 Lower surface 13 Lift generating splitter 14 Lift generating splitter 110 Upper end surface 120 Lower end surface

Claims (10)

  The pair of wind-receiving face bodies 1 have a taper shape in the vertical direction, and have a lift generation splitter 13 that can generate lift by an updraft and reduce torque at startup, and is formed into a blade streamlined streamlined shape. Savonius vertical axis windmill.   The pair of wind-receiving face bodies 1 have a vertically tapered shape, and have a lift generating splitter 13 that can generate lift by an updraft and reduce the torque at the time of startup, causing a twist in the vertical direction of the blade, A Savonius vertical axis windmill characterized by being formed into a meat streamline.   The pair of wind-receiving face bodies 1 have a taper shape in the vertical direction, and have a lift generation splitter 13 that can generate lift by an updraft and reduce the torque at the time of start-up. A Savonius vertical axis wind turbine characterized by being formed into a thick streamlined cross section.   The pair of wind-receiving face bodies 1 has a taper shape in the vertical direction, and has a lift generation splitter 13 that can generate lift by an updraft and reduce the torque at the time of starting, and causes deviation and twist in the vertical direction of the blade. The Savonius vertical axis windmill is characterized by being formed into a thick streamlined blade cross section.   5. A Savonius vertical axis wind turbine characterized in that the wind receiving surface body 1 according to any one of claims 1 to 4 is an FRP blade made of a carbon material.   The Savonius vertical axis wind turbine according to any one of claims 1 to 4 is axially coupled to a gyromill vertical axis wind turbine via a shaft mechanism (clutch), and is axially coupled using an output of the Savonius vertical axis wind turbine. The Savonius vertical is characterized by assisting the start-up of the gyromill vertical axis wind turbine, and by reversing the direction of each shaft rotation so as to transmit each shaft rotation to the generator to increase the power generation output. Wind power generator using an axial windmill.   The wind power using the Savonius vertical axis windmill according to claim 6, further comprising an axis mechanism that assists the initial rotation of the gyromill vertical axis windmill and cuts the rotation assistance when the rotational speed increases. Power generation device.   The chord length of the wind turbine blade of the gyromill vertical axis wind turbine is designed so that the ratio of the blade length to the rotation circumference (solidity) is 0.18 to 0.20. The wind power generator using the said Savonius vertical axis windmill of description.   The wind power using the Savonius vertical axis wind turbine according to claim 8, wherein the thickness of the wind turbine blade of the gyromill vertical axis wind turbine is designed so that the blade thickness ratio of the wind turbine blade is 0.2. Power generation device. The wind turbine generator using the Savonius vertical axis wind turbine according to claim 9, wherein a warp of a wind turbine blade of the gyromill vertical axis wind turbine is designed to be 5%.