JP2021119299A - Wind power generation device and wind power generation unit - Google Patents

Abstract

To provide a wind power generation device that can efficiently generate power with a weak wind even if it is compact.SOLUTION: A wind power generation device comprises a wind tunnel 12 constituting a flow passage for introducing and passing a wind. A power generator 20 in which a rotating shaft is arranged along the flow passage, and a piezoelectric element 28 to be warped by a force of the wind flowing through the flow passage are comprised inside the flow passage. An impeller 22 is provided in the power generator 20. The flow passage comprises at least a wind collection part 14 provided with an inclination so as to narrow an opening area of the flow passage toward the impeller 22 from an inlet of the wind tunnel 12, an expansion part 16 located behind the impeller 22, and expanding the opening area, and an exhaust part 18 in which the piezoelectric element 28 is arranged behind the expansion part 16.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wind power generation device, and more particularly to a wind power generation device suitable for power generation in a weak wind environment, and a unit provided with the wind power generation device.

Wind power generation using a wind turbine generally requires a predetermined amount of wind power (wind speed) or higher. Therefore, it is considered that the amount of power generation can be increased by realizing the possibility of power generation in a weak wind environment.

Here, in order to generate electricity in a weak wind, it is common to (a) increase the wind speed on the wind receiving surface, and (b) increase the number of poles in the case of an alternator. In addition, when power generation is possible in weak winds, excessive rotational force is applied in strong winds, which may cause damage to equipment.Therefore, measures have been taken to stop the function or reduce the number of rotations and the amount of power generation. ing.

For example, in the wind power generator disclosed in Patent Document 1, the air guide port that guides the wind to a rotating body that rotates by receiving the wind has an expansion / contraction structure. Then, by expanding the wind guide port when the wind is weak and contracting the wind guide port when the wind is strong, it is configured to give the same amount of wind power to the rotating body even when the wind is weak or strong, and the amount of power generation is stabilized. I am trying to do it.

Further, in the wind power generator disclosed in Patent Document 2, a generator equipped with a wind turbine is arranged at the center, and a wind guide path whose flow path is narrowed toward the center side is arranged around the entire circumference thereof. It has a structure. The generator equipped with the wind turbine is configured to be capable of directing the wind turbine in the direction in which the wind blows. According to such a configuration, the wind from the front of the wind turbine accelerates due to the wind collecting effect by the wind guide path, and negative pressure is generated behind the wind turbine due to the expansion of the wind guide path, which causes a pull-in effect (wind lens). Will occur.

Japanese Unexamined Patent Publication No. 2003-49760 Japanese Unexamined Patent Publication No. 2014-95305

All of the wind power generation devices disclosed in the above patent documents are large-scale and cannot generate power in a weak wind (about 1 m / s) in an urban area. In particular, the wind power generator disclosed in Patent Document 1 requires a means for measuring the wind force and a mechanical mechanism for expanding / contracting the air guide.

Therefore, an object of the present invention is to provide a wind power generation device and a wind power generation unit capable of efficiently generating power with a weak wind even if the structure is simplified and the structure is simplified.

The wind power generator according to the present invention for achieving the above object has a wind tunnel constituting a flow path for taking in and passing wind, and a rotation axis is arranged along the flow path inside the flow path. The generator is provided with a piezoelectric element that bends due to the force of the wind flowing through the flow path. The generator is provided with an impeller, and the flow path is provided with at least the impeller from the entrance of the wind tunnel. A wind collecting portion that is inclined so as to narrow the opening area of the flow path toward the air, an expanding portion that is located behind the impeller and widens the opening area, and the piezoelectric portion behind the expanding portion. It is characterized by having an exhaust portion in which the element is arranged.

Further, in the wind power generation device having the above-mentioned characteristics, the wind collecting portion constitutes a plurality of flow paths, each flow path is formed in a funnel shape, and the downstream side is directed to the blades of the impeller. It is characterized by that. By having such a feature, it is possible to improve the rotational moment given to the impeller. Therefore, the cut-in wind speed can be reduced.

Further, in a wind power generator having the above-mentioned characteristics, the generator is supported by an elastic member that expands and contracts in a direction along a flow path, and the elastic member changes the pressing force of the wind with respect to the impeller. It is characterized in that the support position of the generator is moved in the direction along the flow path according to the above. By having such a feature, it is possible to make an escape route for the wind in a strong wind. Therefore, the set value of the cutout wind speed can be increased.

Further, in the wind power generation device having the above-mentioned characteristics, the flow path is provided with an inclined surface so that the cross-sectional area of the exhaust portion is smaller than the cross-sectional area of the expanded portion. .. According to having such a feature, the wind speed in the exhaust part can be improved, and the power generation effect by the piezoelectric element can be improved.

Further, the wind power generation unit for achieving the above object is characterized in that an electronic device is provided on the power output side of the wind power generation device having the above-mentioned characteristics.

According to the wind power generation device having the above-mentioned characteristics, it is possible to efficiently generate power with a weak wind even if it is small. Further, according to the wind power generation unit having the above characteristics, the degree of freedom of application to a weak wind location can be improved.

It is sectional drawing which shows the structure of the wind power generation apparatus which concerns on embodiment. It is a figure which shows the structure of the left side surface of FIG. It is a figure which shows the structure of the AA cross section in FIG. It is a figure which shows the structure of the BB cross section in FIG. It is a figure which shows the state which the impeller is pushed to the downstream side of a flow path by wind pressure. It is a figure which shows the example of the case where the wind power generation device which concerns on embodiment is applied to the door pocket of the platform door of a train. It is a figure which shows the right side surface of FIG.

Hereinafter, embodiments of the wind power generation device and the wind power generation unit of the present invention will be described in detail with reference to the drawings. It should be noted that the embodiment shown below is one of the preferred embodiments for carrying out the present invention, and even if a part of the configuration is changed within the range in which the effect of the present invention is exhibited, the present invention is used. Can be considered part.

[Constitution]
First, the configuration of the wind power generation device 10 according to the present embodiment will be described with reference to FIGS. 1 to 4. In the drawings, FIG. 1 is a cross-sectional view showing the configuration of the wind power generation device according to the embodiment, and FIG. 2 is a diagram showing the configuration of the left side surface of FIG. Further, FIG. 3 is a diagram showing the configuration of the AA cross section in FIG. 1, and FIG. 4 is a diagram showing the configuration of the BB cross section.

The wind power generation device 10 according to the present embodiment is basically composed of a wind tunnel 12 constituting a flow path, a generator 20 arranged inside the flow path (ventilation path), and a piezoelectric element 28.

The wind tunnel 12 includes at least a flow path having a wind collecting portion 14, an expanding portion 16, and an exhaust portion 18, and plays a role of taking in and passing wind into the inside of the flow path. The wind collecting portion 14 is a region provided with an inclination from the inlet side of the wind tunnel 12 toward the impeller 22, which will be described in detail later, so as to narrow the opening area of the flow path. The expansion portion 16 is a space located on the downstream side of the arrangement position of the impeller 22, and is a region configured to widen the opening area as compared with the downstream end portion (small diameter portion) of the wind collecting portion 14. be.

The exhaust portion 18 is a flow path located on the downstream side of the expansion portion 16, and the opening area is narrower than that of the portion where the opening area of the expansion portion 16 is widened so as to increase the velocity of the wind passing through the flow path. It is configured. Further, in the wind tunnel 12 according to the present embodiment, the outlet of the exhaust unit 18 is provided in the upper part (or the side surface) of the wind tunnel 12. With such a configuration, the outlet portion (the dashed shaded portion shown in the exhaust portion 18 in FIG. 1) is due to the speed difference between the wind passing through the outer periphery of the wind tunnel 12 and the wind passing through the inside of the wind tunnel. Negative pressure is generated, which has the effect of improving the flow velocity of the wind passing through the flow path. In addition, in order to increase the negative pressure generated at the outlet portion of the flow path, unevenness or the like may be provided on the outer periphery of the wind tunnel 12 to improve the flow velocity of the passing wind. The broken line arrow shown in FIG. 1 schematically represents the flow of wind.

The generator 20 is provided with a coil and a magnet (not shown) in a casing to generate electric power by rotating the rotating shaft, and includes an impeller 22 for rotating the rotating shaft by wind power. The generator 20 is fixed to the support portion 24 provided in the expansion portion 16 constituting the flow path via the elastic member 26. The elastic member 26 plays a role of compressing by receiving a force along the arrangement direction of the flow path, that is, the direction in which the wind flows, and moving the arrangement position of the generator 20 to the downstream side of the flow path. The specific configuration of the elastic member 26 does not matter, but it is preferable that the elastic member 26 has elasticity and resilience, such as a coil spring.

The impeller 22 can be assumed to have a wide variety of forms, but in the present embodiment, it has a fan-shaped three-blade blade as shown in FIG. 3 and has a large wind receiving area. In the present embodiment, the position of the generator 20 is determined so that the impeller 22 is located at the boundary between the wind collecting portion 14 and the expanding portion 16 in a state where the impeller 22 is not subjected to the pressing force due to the wind. With such a configuration, when the generator 20 moves to the downstream side of the flow path, the space between the tip of the impeller 22 and the flow path becomes wide, and the space through which the wind can escape can be widened (FIG. 5). reference).

The piezoelectric element 28 is an automatic valve that hangs down from the upper part of the boundary portion between the expansion portion 16 and the exhaust portion 18 and has an opening amount according to the flow rate. The size of the piezoelectric element 28 is slightly smaller than the opening of the exhaust portion 18 so that it does not become a block valve when the flow rate is small. When the flow rate is high, it opens wide and the deflection becomes large, and electric power is generated. In the example shown in FIG. 4, a plurality of slits 28a are provided in the piezoelectric element 28 so as not to form a blocking valve to reduce the rigidity of the piezoelectric element and make it easy to bend. With such a configuration, it is possible to generate electric power in a weak wind and reduce the pressure loss in the flow path.

[Details of the wind collecting section]
In particular, in the present embodiment, the same number of funnel-shaped wind collecting cones 14a as shown in FIGS. 1 and 2 are arranged with respect to the wind collecting portion in the same number as the number of impellers 22 (three in the present embodiment). ), The wind taken in is preferentially guided to the blade portion of the impeller 22. The impeller 22 rotates by receiving the wind pressure from the wind collecting portion 14 on the blades. The rotational moment M at this time can be expressed by Equation 1.

ここで、Ｆを作用する力、ｒを回転中心からの距離とすると、回転モーメントＭは、回転中心から遠い位置に風圧を作用させることで、同じ風力（風圧）であっても、羽根車２２に対して高い回転モーメントを与えることがきるということができる。よって、弱風であっても、羽根車２２に対して高い回転モーメントを与えることができ、羽根車２２に対するカットイン風速（発電開始風速）を低減することが可能となる。
また、集風部１４に集風コーン１４ａを配置して流路に風を導入することにより、集風コーン１４ａの無い中心部（図１において集風部１４に破線斜線で示す領域）には、負圧が生じる。この負圧により、集風コーン１４ａの内部を流れる風を引き込む効果を奏し、風速を高めることができる（風レンズと同様な効果）。

Here, assuming that the force acting on F and r are the distance from the center of rotation, the rotation moment M is the impeller 22 even if the wind pressure is the same by applying the wind pressure to a position far from the center of rotation. It can be said that a high rotational moment can be given to the vehicle. Therefore, even if the wind is weak, a high rotational moment can be applied to the impeller 22, and the cut-in wind speed (power generation start wind speed) with respect to the impeller 22 can be reduced.
Further, by arranging the wind collecting cone 14a in the wind collecting portion 14 and introducing the wind into the flow path, the central portion without the wind collecting cone 14a (the region indicated by the broken line diagonal line in the wind collecting portion 14 in FIG. 1) is formed. , Negative pressure is generated. Due to this negative pressure, the effect of drawing in the wind flowing inside the wind collecting cone 14a can be achieved, and the wind speed can be increased (similar effect to that of a wind lens).

[Details of expansion and exhaust]
The expansion portion 16 is provided with a portion that widens the cross-sectional area of the flow path as compared with the downstream end portion of the wind collecting portion 14, so that when the impeller 22 (generator 20) is pushed down by wind pressure, the expansion portion 16 is provided. It is possible to create an escape route for the wind. Therefore, it is possible to suppress an excessive increase in the rotation speed of the impeller 22, and it is possible to set a high cutout wind speed (power generation stop wind speed).

On the downstream side of the expansion portion 16, an inclined surface that narrows the cross-sectional area of the flow path toward the exhaust portion 18 is provided. With such a configuration, it is possible to increase the flow velocity of the air (wind) flowing into the exhaust unit 18.

Here, for the cross-sectional area Sa of the exhaust portion 18 (opening area of the BB cross section), the area on the downstream side of the wind collecting portion 14 (sum of the opening areas of the wind collecting cone 14a in the AA cross section) is set to S1. In some cases, it is desirable to have an area of S1 or more. This is to prevent the pressure on the upstream side of the piezoelectric element 28 from increasing and hindering the introduction of wind into the wind tunnel 12.

[Example]
As one embodiment in carrying out the present invention, the radius r of the impeller 22 is set to 0.3 m, and the ratio of energy obtained by rotating the impeller 22 by wind power by the generator 20 according to the embodiment ( Assuming that the power coefficient) Cp value is 0.2, the force (wind energy) Pe value obtained by the impeller 22 can be expressed by Equation 2.

ここで、ρは、空気密度であり、ρ＝１．２９３とする。また、Ａは、受風面積であり、本実施例では、Ａ＝πｒ^２である。さらに、Ｖは風速を示す。周辺風速Ｖ_０＝１ｍ／ｓ時に、集風部１４の風上側開口面積に対して風下側開口面の割合を０．４４と仮定すると、加速後の風速Ｖは２．２７ｍ／ｓとなる。

Here, ρ is the air density, and ρ = 1.293. Further, A is a wind receiving area, and in this embodiment, A = πr ² . Further, V indicates the wind speed. Assuming that the ratio of the leeward opening surface to the leeward opening area of the wind collecting portion 14 is 0.44 when the ambient wind speed V _{0 = 1 m / s, the wind speed V after acceleration is 2.27 m / s.}

Under such conditions, the force Pe value obtained by the impeller 22 is 0.4 W. Here, assuming that the increase value of the rotational moment due to the concentration of wind power on the blade portion by the wind collecting cone 14a is 1.2 times, the Pe value is 0.48 W.

Here, when the Cp value is 0.2, the remaining 0.8 energy is flowing behind the impeller 22. Therefore, 1.6 W of energy becomes unused energy. About half of this energy contributes to the force that bends the piezoelectric element 28, and when the power generation efficiency of the piezoelectric element 28 is about 10%, 0.08 W of energy can be obtained. Therefore, it is considered that the wind power generation device 10 of the present embodiment can obtain 0.56 W of energy.

[Action / Effect]
According to the wind power generator 10 having the above configuration, the effect of the wind collecting unit 14 in which the wind collecting cone 14a is arranged accelerates the wind taken into the flow path even if the wind is weak, and the impeller The 22 can be rotated efficiently to promote the power generation of the generator 20. Further, the energy that did not contribute to the rotation of the impeller 22 remains in the wind that has passed through the impeller 22 from the wind collecting portion 14 and has flowed into the expansion portion 16. When this energy (wind) flows into the exhaust unit 18, the piezoelectric element 28 provided in the exhaust unit 18 is oscillated. As a result, power is generated by the piezoelectric element 28.

That is, in the present embodiment, electric power is obtained from both the generator 20 that generates electric power by the rotational action and the piezoelectric element 28 that generates electric power by the rocking action generated by the energy that does not contribute to the rotation.

Further, in the wind power generator 10 according to the present embodiment, when the wind force is strengthened, the impeller 22 and the generator 20 provided with the impeller 22 are moved to the downstream side by the wind pressure as shown in FIG. As a result, the gap between the impeller 22 and the inner wall of the flow path (the portion indicated by the broken line circle in FIG. 5) is widened, and a wind escape path can be created. Therefore, it is possible to avoid a situation in which the rotation of the impeller 22 exceeds the dangerous rotation speed and is damaged due to the excessive strong wind acting on the impeller 22. Further, power can be generated by swinging the piezoelectric element 28 due to the escaped wind. Since the generator 20 is supported by the elastic member 26, when the wind becomes weak again, it returns to the original position.

Since the power generation device 10 according to the above embodiment is small, for example, as shown in FIGS. 6 and 7, a plurality of wind power generation devices 10 (in the example shown in FIG. 6) are on the track side of the door pocket 52 of the platform door 50 of the train. When the wind tunnel 12 is one and the flow paths (a form in which a plurality of wind collecting portions 14) are arranged in an integrated manner), power can be generated from a weak wind such as a running wind of a train.

At this time, by connecting a light emitter, a residual prevention sensor 54, or the like to the output side of the wind power generation device, it acts as a power source for these electronic devices.

10 ………… Wind power generator, 12 ………… Wind tunnel, 14 ………… Wind collecting part, 14a ………… Wind collecting cone, 16 ………… Expansion part, 18 ………… Exhaust part, 20 ………… Power generation Machine, 22 ……… Impeller, 24 ……… Support, 26 ……… Elastic member, 28 ……… Piezoelectric element, 28a ……… Slit, 50 ……… Platform door, 52 ……… Door pocket, 54 ……… Remaining prevention sensor.

Claims (5)

It has a wind tunnel that constitutes a flow path that takes in and passes wind.
Inside the flow path, a generator having a rotating shaft arranged along the flow path and a piezoelectric element flexed by the force of the wind flowing through the flow path are provided, and the generator has an impeller. As well as being provided
The flow path is located at least behind the impeller and a wind collecting portion that is inclined so as to narrow the opening area of the flow path from the entrance of the wind tunnel toward the impeller. A wind power generator having an expanding portion to be expanded and an exhaust portion in which the piezoelectric element is arranged behind the expanding portion. The wind collecting part is
The wind power generator according to claim 1, wherein a plurality of flow paths are formed, each flow path is formed in a funnel shape, and the downstream side is directed to the blades of the impeller. The generator is supported by an elastic member that expands and contracts in the direction along the flow path.
The first or second aspect of the present invention, wherein the elastic member is configured to move the support position of the generator in a direction along the flow path in response to a change in the pressing force of the wind with respect to the impeller. Wind power generator. The method according to any one of claims 1 to 3, wherein the flow path is provided with an inclined surface so that the cross-sectional area of the exhaust portion is smaller than the cross-sectional area of the expanded portion. Wind power generator. A wind power generation unit characterized in that an electronic device is provided on the power output side of the wind power generation device according to any one of claims 1 to 4.

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