JP2002213343A - Wind speed-up device and wind power generator using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wind speed-up device capable of efficiently increasing speed of wind with a simple structure. SOLUTION: This wind speed-up device is composed of a long cylindrical wind tunnel body 1a expanded from a flow-in port 2 of wind toward a flow-out port 3, a flow-in guide member 5 opened toward the outside 3 with a curved face is formed on an opening edge of the flow-in port 2 of the wind tunnel body 1b, a collar-shaped flange 6 expanded toward the outside is formed on an opening edge of he flow-out port 3, and the neighborhood of the flow-in port 2 is adopted as the wind power taking-out position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wind speed increasing device for speeding up a flow of wind and using the same for a wind power generator, a ventilation device, and the like, and a wind power generator using the same.

[0002]

2. Description of the Related Art In recent years, in the field of power generation, wind power generation devices have been receiving attention from the viewpoints of oil-free energy and environmental cleanliness. The wind power generator uses the flow of wind in the natural world. However, sufficient wind power may not be obtained depending on the topography of the installation location, the weather, and other conditions. for that reason,
It is considered that the flow of the weak wind is accelerated by some means for power generation.

FIG. 15 shows an example of a conventional wind power generator having a wind speed increasing means. FIG. 15 is an external view of the wind power generator, and FIG. 16 is a longitudinal section showing a main part of the wind power generator of FIG. FIG.

The wind power generator shown in FIG. 15 is provided with a diffuser 12 using an airplane wing so as to surround the periphery of a wind turbine 11 for power generation, and the wind speed is increased by the diffuser 12 to rotate the wind turbine 11. (DG Phillip
s, p. J. Richards, R.A. G. FIG. J. Fl
ay: Proceedings of Computa
Tional Wind Engineering 2
000, pp. 189-192).

As shown in FIG. 16, the diffuser 12 has a plurality of slots (gap) 13 in the middle thereof like a flap of an airplane wing. The slot 13 takes in the external wind and adds momentum to the flow of the wind inside the diffuser 12 so that the wind flowing inside the diffuser 12
This is to prevent the film 2a from being peeled off.

That is, the conventional diffuser 12 controls the flow along the inner surface 12a of the diffuser 12 like a combination of a main wing and a flap of an airplane, so that the wind in the diffuser 12 passes smoothly. Is what you do. Therefore,
More wind flows into the diffuser 12,
The wind near the inlet of the diffuser 12 is accelerated, and the windmill 11 surrounded by the diffuser 12 is rotated.

[0007]

The above conventional diffuser 12
When the wind speed is increased, it is necessary to allow the wind flowing into the wind tunnel body 11 to smoothly pass along the inner surface 12a. For this reason, a plurality of openings 13 and inlet rings (not shown) are provided in the wind tunnel 11 to improve the speed increasing effect.

However, the smooth flow along the inner surface 12a of the wind tunnel 11 is disturbed by the rotation of the windmill 11 inside the diffuser 12, and the wind speed cannot be increased to meet the expected power generation. Further, if a plurality of openings 13 and inlet rings are provided, the structure of the diffuser 12 becomes complicated.

In view of the above, the present invention provides a wind speed increasing device capable of efficiently increasing the flow of wind with a simple structure and a wind power generator using the same.

[0010]

Means for Solving the Problems In order to solve the above problems, the present inventors have proposed a long cylindrical wind tunnel body arranged in an open space with a flow of wind for the purpose of collecting wind. , A contraction type shown in FIG. 1A, a neutral type shown in FIG. 1B, and an enlarged type shown in FIG. Figure 1
The contraction type shown in (a) has a shape in which the inflow port is wide and the outflow port is narrow with respect to the flow of the wind, and the neutral type shown in FIG. 1 (b) has a shape in which the inflow port and the outflow port have the same width, and FIG. The enlarged type shown in c) has a shape with a narrow inlet and a wide outlet.

Here, assuming that there is no separation or the like, the velocity distribution of the wind flow in the wind tunnel arranged in the closed space is set to be inversely proportional to the cross-sectional area of the wind tunnel from the viewpoint of mass conservation. Distribute. Also, the velocity distribution of the wind flow in the wind tunnel arranged in the open space is the same as the internal flow when the wind flow is arranged in the closed space. However, in an open space, the wind does not necessarily need to flow into the wind tunnel, and the wind tunnel may simply be an obstacle, and the wind may flow around the wind tunnel.

[0012] Of the three types of wind tunnel shown in FIG.
In the case of the neutral type shown in (b), if the influence of the boundary layer due to the inner wall is ignored, the wind flows without being affected by the wind tunnel. Therefore, the inventors examined in detail the flow of the wind, the state of the pressure and the velocity distribution, and the like for the contraction type shown in FIG. 9A and the enlarged type shown in FIG. 10C.

In the experiment, as shown in FIG. 2, a model of the wind tunnel body has a square cross section of 12 × 12 cm and 24 × 24 cm, and a length L = 92 c.
m hollow pyramid was used. The cross-sectional area ratio between the inlet and the outlet of the wind tunnel body is 4, and the opening angle is about 3.7 degrees. With respect to such a wind tunnel, the static pressure distribution and the wind velocity distribution on the center line of the wind tunnel were measured. The static pressure was measured with a diameter of 3 m.
The end of a copper pipe of m was closed and rounded so as to be smooth, and a static pressure tube having four 0.5 mm-diameter holes formed on the circumference at a position of 1 cm from the tip was used. In addition, a hot wire anemometer having a spherical sensor having a diameter of 2 mm was used for measuring the wind speed.

[0014] external to approach wind velocity U _∞ was set to 5m / s. Here, the approaching wind speed U _で is an upstream wind speed that is not affected by an object such as a wind tunnel. FIG. 3 shows the static pressure distribution at this time, and FIG. 4 shows the wind speed distribution. The static pressure distribution in FIG. 3 shows a difference from a position where there is no influence of the wind tunnel.
The horizontal axis in FIGS. 3 and 4 is the measured horizontal position X
Is dimensionless by the length L. The vertical axis of FIG. 3 represents the ratio dimensionless by dynamic pressure due to the wind velocity U _∞ to approach the static pressure difference, and the vertical axis in FIG. 4 represents the ratio dimensionless by wind to approach the speed of the wind. In addition, X represents the axial distance based on the inflow port cross section. FIG. 5 is a diagram visualizing the state of the flow of wind by the smoke wire method.

From these results, the following can be understood. Since the wind tunnel is located in an open space,
The static pressure at the inlet and outlet of the model must be the same as the static pressure of the surrounding atmosphere. Actually, looking at the static pressure difference distribution in FIG. 3, the static pressure difference is almost zero near the inflow port and the outflow port. The static pressure inside the wind tunnel is always a positive pressure in the contraction type and a negative pressure in the expansion type. In addition, the degree of the positive pressure or the negative pressure is 30 to 40 from the inlet.
The maximum value is obtained at the position of mm, and gradually becomes zero toward the outlet. Corresponding to this pressure distribution, as shown in FIG. 4, the wind speed becomes extremely slow in the vicinity of the inlet in the contraction type with respect to the surrounding wind speed, and gradually recovers toward the outlet. On the other hand, in the expansion type, the speed is rapidly increased near the inflow port to increase the speed, and decreases toward the outflow port. The maximum wind speed is about 1.8 times the surrounding wind speed.

Referring to the state of the flow in FIG. 5, in the contraction type, the wind is largely curved so that the wind is excluded outside the wind tunnel body in front of the inlet. On the other hand, in the enlarged type, it can be seen that the wind around the wind tunnel is flowing in a funnel shape so as to be sucked into the inflow port. 30 to 40 mm from the inlet with an enlarged wind tunnel
The reason why the maximum wind velocity is obtained at the position is that the cross-sectional area around the flow is substantially minimized because the flow separates at the inflow port.

From the results of the above experiments, it was found that the long cylindrical wind tunnel body which gradually expands in the direction of the flow of the wind can create a high wind speed area inside the wind tunnel body. It can be seen that the extent of the increase depends on the resistance when flowing into the wind tunnel and the static pressure at the outlet of the wind tunnel. The present invention is directed to a wind speed increasing device that can increase the speed of the wind most effectively in consideration of the characteristics of such an enlarged wind fuselage.

That is, the wind speed-increasing device of the present invention is constituted by a long cylindrical wind tunnel body that expands from the wind inlet to the outlet, and the vicinity of the inlet is a wind take-out position. This allows the slow wind flow at the wall of the wind tunnel to be entrained by the wind flow at the center of the wind tunnel that flows in from the front of the inlet, and the wind at the center of the axis and the wind outside the wind tunnel at the back of the outlet. With this flow, the flow of the slow wind on the wall portion inside the wind tunnel is entrained, and a high wind speed region for extracting wind power can be obtained near the inflow port inside the wind tunnel.

The wind power generator of the present invention uses such a wind speed increasing device and arranges a wind turbine for power generation at a position for taking out the wind near the inlet. This allows
Even when the outside wind is weak, the wind turbine located near the inlet inside the wind tunnel, which is the high wind speed area of the wind tunnel of the wind intensifier, can be effectively rotated, and the power generation capacity as a wind power generator increases It is possible to improve the efficiency.

Further, it is desirable to provide an inflow guide piece having a curved surface toward the outside at an edge of the inflow port. This allows the wind near the front of the inlet of the wind tunnel to be smoothly drawn in by the flow around the axial center of the wind tunnel, and the wind that has flowed into the wind tunnel is not separated from the wall of the wind tunnel near the inlet. Since it passes through the inside, a region with a high wind speed can be obtained more efficiently.

On the other hand, it is desirable to provide a flange-like piece which spreads outward at the edge of the outlet. Thereby, the wind flowing outside the wind tunnel collides with the flange-shaped pieces to form a vortex, and the pressure near the outlet of the wind tunnel becomes low. A high wind speed area can be obtained.

Here, the ratio of the length of the wind tunnel to the diameter of the inlet of the wind tunnel is preferably 0.5 or more, more preferably 1 or more. Thereby, the wind speed can be more efficiently extracted by setting the speed increase ratio of the wind extraction position to 1.2 or more. Further, if this ratio is set to 2 or more, the speed increase ratio at the wind take-out position can be set to 1.5 or more without providing the inflow guide pieces and the flange-shaped pieces at the edges of the inflow port and the outflow port, respectively. It is possible to extract wind power more efficiently.

The wind tunnel body can be formed in various shapes such as a rectangular tube, and it is particularly preferable that the inner wall surface has a smooth cylindrical shape in order to allow the wind to pass smoothly.
Thereby, the action of entraining the slow-flowing wind on the wall portion of the wind tunnel inside the wind tunnel by the wind passing through the wind tunnel inside can be further strengthened, and a region with a high wind speed can be obtained more efficiently.

Further, the inclination angle of the side trunk portion with respect to the axis of the wind tunnel body of the present invention is desirably in the range of 2 to 5 °. The present inventors have found that when the inclination angle is less than 2 °, the effect of increasing the speed increase ratio tends to be reduced even if the ratio of the length of the wind tunnel body to the diameter of the inflow port of the wind tunnel body is reduced, and the inclination angle is reduced. If the angle exceeds 5 °, the effect of entraining the slow-flowing wind on the wall of the wind tunnel tends to be weak, and the slowest wind on the wall of the wind-tunnel can be entrained most efficiently within the range of 2 to 5 °. It is found by experiments that

In the wind power generator according to the present invention,
It is desirable that the side trunk portion of the wind tunnel be provided with an opening / closing port for introducing wind outside the wind tunnel. By opening and closing the opening and closing port according to the strength of the wind flowing from the inlet, it is possible to reduce and adjust the wind speed in the high wind speed region obtained in the wind tunnel, and it is possible to control the fluctuation of the power generation amount Become.

At this time, if the system further comprises means for detecting the flow velocity of the wind flowing into the inlet and control means for opening the opening and closing when the flow velocity is equal to or higher than the set value, the wind flowing from the inlet is further provided. When the flow velocity is too high, the opening and closing port is automatically opened,
The wind speed in the high wind speed region obtained in the wind tunnel can be decelerated and adjusted to control fluctuations in the amount of power generation, and also to protect the wind turbine from excessive wind and prevent damage to the wind turbine.

[0027]

(Embodiment 1) FIG. 6 shows a wind tunnel body 1a constituting a wind speed increasing device according to a first embodiment of the present invention.
FIG. 7 is an explanatory view showing the state of the flow of wind by the wind tunnel body 1a of FIG.

As shown in FIG. 6, a wind tunnel body 1a, which is a main component of the wind speed increasing device according to the first embodiment, is a long cylindrical hollow body formed using a metal material such as aluminum. It has a wind inlet 2 at the front end (left side in FIG. 6) and an outlet 3 at the rear end (right side in FIG. 6). The side plate 4 of the wind tunnel 1a is inclined with respect to the axis of the wind tunnel 1a so as to gradually expand from the inlet 2 to the outlet 3 of the wind tunnel 1a. That is, the cross-sectional area on the inflow side of the wind to the wind tunnel body 1a is smaller than the cross-sectional area on the outflow side.

According to such a wind speed increasing device, FIG.
As shown in FIG. 7A, the slow flow wind B on the wall of the wind tunnel body 1a is engulfed by the central flow of the wind flowing from the inflow port 2 of the wind tunnel body 1a, and as shown in FIG. Body 1a
At the rear of the outlet 3 of the wind turbine 1a, the wind D of the slow flow behind the wind tunnel 1a is entrained and flows by the central flow A and the external flow C. Region E can be obtained.

(Embodiment 2) FIG. 8 is a longitudinal sectional view of a wind tunnel body 1b constituting a wind speed increasing device according to a second embodiment of the present invention. The wind speed increasing device according to the second embodiment has a configuration similar to that of the wind turbine 1a according to the first embodiment.
As shown in FIG. 8, an inflow guide piece 5 is provided at the edge of the inflow port 2 of FIG.

In the case of the wind speed increasing device in the first embodiment,
Although the degree of increase in the wind speed in the high wind speed region is affected by the wind inflow resistance, in the wind speed increasing device according to the second embodiment shown in FIG. 8, the wind is smoothly drawn into the inflow port 1 by the inflow guide piece 5. While guiding, the wind flowing from the inflow port 1 is prevented from peeling off from the inner wall surface near the inflow port of the wind tunnel body 1b, so that the generation of the high wind speed region can be promoted, and the high wind speed region can be obtained more efficiently. .

(Embodiment 3) FIG. 9 is a longitudinal sectional view of a wind tunnel body 1c constituting a wind speed increasing device according to a third embodiment of the present invention. The wind speed increasing device according to the third embodiment has a configuration similar to that of the wind turbine 1a according to the first embodiment.
At the rim of the outlet 3 of FIG. 3C, a flange 6 is provided which extends outward as shown in FIG.

In the case of the wind speed increasing device according to the first embodiment, the degree of increase in the wind speed in the high wind speed region is affected by the static pressure at the outlet 3 of the wind tunnel body 1a. In the wind speed increasing device, the static pressure at the outlet 3 is reduced by the flange 6 at the rim of the outlet 3 of the wind tunnel body 1c. That is, the wind flowing outside the wind tunnel 1c collides with the flange 6 to form a vortex, and the wind tunnel 1c
Since the pressure near the outlet 3 becomes low, the wind of the slow flow on the wall portion of the wind tunnel body 1c is drawn out, and the generation of the high wind speed region is promoted, so that the high wind speed region can be obtained more efficiently.

(Embodiment 4) FIG. 10 is a longitudinal sectional view of a wind tunnel body 1d constituting a wind speed increasing device according to a fourth embodiment of the present invention. The wind speed increasing device according to the fourth embodiment is shown in FIG.
As shown in FIG. 0, both the inflow guide piece 5 in the second embodiment and the flange 6 in the third embodiment
d, and as described above, the synergistic effect of the inflow guide piece 5 and the flange 6 assists the generation of a high wind speed region.

FIG. 11 is a diagram showing the change characteristics of the speed increase ratio of the maximum wind speed with respect to the length of each of the wind turbine bodies 1a, 1b, 1c, 1d constituting the wind speed increasing device in the first to fourth embodiments. is there. The horizontal axis L / D is the ratio of the length L of the wind tunnel bodies 1a to 1d to the diameter D of the inflow port 3 of the wind tunnel bodies 1a to 1d. Ordinate U _max / U _∞ is the ratio of the maximum wind U _max in the vicinity of the inlet 2 on the central axis of the wind tunnel body 1 a to 1 d against external to approach wind velocity U _∞ of augers 1 a to 1 d.

As shown in FIG. 11, the wind tunnel bodies 1a to 1d
In each case, the maximum gradually increases as the length L increases.
It is changing so that the wind speed increases. Also, inflow guidance
Wind tunnel 1b, 1c, 1d provided with piece 5 and flange 6
Is the speed increase ratio U compared with the wind tunnel body 1a. _max/ U_∞Is high. In particular,
Wind tunnel 1 provided with both inflow guide piece 5 and flange 6
In d, when L / D = 2.6 or more, the speed increase ratio U_max/ U
_∞= 2 or more, which is the most effective for increasing the wind speed.
I understand that The length D of the wind tunnel bodies 1a to 1d is long.
Moderate, but considering the installation conditions and economics, its length
Needless to say, there is a limit.

In the above embodiment, the wind tunnel 1
Although the case where a to 1d is a quadrangular cylinder is described, when this is made cylindrical and the inclination angle of the side trunk is set to a range of 2 to 5 °, the value of the maximum wind speed is most effectively increased. can do. Figure 12 is a diagram showing a speed increasing ratio U _max / U _∞ for φ angle of inclination of the side body portion of the wind tunnel body 1a. As shown in FIG. 12, when the inclination angle of the side trunk is in the range of 2 to 5 °,
The speed increasing ratio U _max / U _∞ can be 1.6 or more.

(Embodiment 5) FIG. 13 is a longitudinal sectional view of a wind power generator using a wind speed increasing device according to a fourth embodiment of the present invention. The wind power generator shown in FIG. 13 has a wind turbine 7 for power generation in which the vicinity of the inflow port 2 on the center axis of the wind tunnel 1d of the wind speed increasing device according to the fourth embodiment is taken as a wind takeout position. The windmill 7 is mounted on the wind tunnel 1d using a support member having a small air resistance.

In the wind power generator having such a configuration, the windmill 7 mounted in the high wind speed region obtained by the synergistic effect of the inflow guide piece 5 and the flange 6 can be efficiently rotated as described above. Thus, even if the installation location of the wind power generator is a place where the outside wind is weak due to conditions such as terrain, a sufficient amount of power generation can be obtained. This means that, in theory, the amount of power generation ∝1 /
The formula of 2ρV ² · A · V∝V ³ is obtained (however, 1 / 2ρV
² : kinetic energy, A: cross-sectional area of the impeller, V: inflow wind speed), that is, a power generation amount proportional to the cube of the wind speed V flowing into the wind fuselage 1d is obtained. It is possible to realize a revolutionary wind power generator.

In this embodiment, the wind tunnel body 1d having both the inflow guide piece 5 and the flange 6 is used, but the wind tunnel bodies 1b and 1c without either the inflow guide piece 5 or the flange 6 are used. Alternatively, the wind tunnel body 1a without both may be used.

(Embodiment 6) FIG. 14 is a longitudinal sectional view showing another embodiment of the wind turbine generator of the present invention. In the wind power generator shown in FIG. 14, the wind power generator according to the fifth embodiment has an opening / closing port 8 for introducing wind outside the wind fuselage at a side trunk portion of a wind fuselage 1d. The opening and closing port 8 opens and closes in accordance with the flow velocity (strong and weak) of the wind flowing into the inflow port 2 so that the wind speed in a high wind speed region obtained in the wind tunnel 1d can be reduced and adjusted. It is possible to control the variation of the quantity.

Further, in the wind power generator according to the present embodiment, a wind sensor (not shown) for detecting the flow velocity of the wind flowing into the inlet 2 and an electromagnetic mechanism for opening and closing the opening when the flow velocity is equal to or higher than the set value. (Not shown), the opening / closing port 8 is automatically opened when the flow velocity of the wind flowing from the inflow port 2 is equal to or higher than a set value, that is, excessively high, and a high wind speed region obtained in the wind tunnel 1d. The deceleration of the wind speed is controlled to control the fluctuation of the power generation. Further, in the case of an extremely strong wind such as a typhoon, the high-speed rotation of the windmill 7 is limited to protect the windmill 7 and prevent the windmill 7 from being damaged.

In each of the embodiments, the wind power generator is mainly described. However, the wind speed increasing device of the present invention can be used not only for the wind power generator but also for an automatic ventilation device and the like. It goes without saying that it includes the above.

[0044]

According to the present invention, the following effects can be obtained.

(1) It is composed of a long cylindrical wind tunnel body that expands from the wind inlet to the wind outlet, and the vicinity of the inlet is the wind take-out position, so that the inside of the wind tunnel body is simple and efficient. A high wind speed region for extracting wind force can be obtained near the inlet of the wind turbine, and a wind power generator using such a wind speed increasing device can reduce the wind tunnel of the wind speed increasing device even when the outside wind is weak. The windmill arranged in the high wind speed region can be rotated effectively, and the power generation capacity is dramatically improved.

(2) By providing an inflow guide piece having a curved surface open outward at the rim of the inflow port, the wind that has flowed into the wind tunnel body does not peel off from the wall surface of the wind tunnel body near the inflow port. As a result, the region with a high wind speed can be obtained more efficiently.

(3) By providing a flange-shaped piece extending outward at the edge of the outlet, the pressure near the outlet of the wind tunnel becomes low, and a slow-flowing wind at the wall of the wind tunnel is drawn out. Thus, a region with a high wind speed can be obtained more efficiently.

(4) By setting the angle of inclination of the side fuselage to the axis of the wind fuselage within the range of 2 to 5 °, the wind with the slow flow on the wall surface inside the wind tunnel is most efficiently entrained and the high wind speed region Can be obtained.

[Brief description of the drawings]

FIG. 1 is a view showing types of shapes of a wind tunnel body, (a) showing a contraction type, (b) showing a neutral type, and (c) showing an enlarged type.

FIG. 2 is a structural diagram of a truncated pyramid as a model of a wind tunnel used for measuring a static pressure distribution and a wind speed distribution.

FIG. 3 is a characteristic diagram of a static pressure difference distribution.

FIG. 4 is a characteristic diagram of a wind speed distribution.

FIG. 5 is a diagram visualizing a state of a wind flow.

FIG. 6 is a longitudinal sectional view of a wind tunnel body according to the first embodiment of the present invention.

FIG. 7 shows a state of a flow of wind by a wind fuselage of FIG. 6,
(A) is an explanatory view of the flow of the wind inside the wind fuselage, (b)
FIG. 4 is an explanatory diagram of a flow of wind in a rear portion of a wind fuselage.

FIG. 8 is a vertical sectional view of a wind tunnel body according to a second embodiment of the present invention.

FIG. 9 is a longitudinal sectional view of a wind tunnel body according to a third embodiment of the present invention.

FIG. 10 is a longitudinal sectional view of a wind tunnel body according to a fourth embodiment of the present invention.

FIG. 11 is a view showing a change characteristic of a speed increase ratio of a maximum wind speed with respect to a length of a wind turbine body in the first to fourth embodiments of the present invention.

12 is a diagram showing a speed increasing ratio U _max / U _∞ for tilt angle φ of the side body portion of the wind tunnel body.

FIG. 13 is a longitudinal sectional view of a wind turbine generator using a wind speed increasing device according to a fourth embodiment of the present invention.

FIG. 14 is a longitudinal sectional view showing another embodiment of the wind power generator using the wind speed increasing device according to the fourth embodiment of the present invention.

FIG. 15 is an external view showing an example of a conventional wind power generator having a wind speed increasing means.

FIG. 16 is a longitudinal sectional view showing a main part of the wind turbine generator of FIG.

[Explanation of symbols]

 1a, 1b, 1c, 1d Wind fuselage 2 Inflow port 3 Outflow port 4 Side plate 5 Inflow guide piece 6 Flange 7 Windmill 8 Opening / closing port

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Koji Ishii, Inventor 1-11-9, Aobadai, Dazaifu City, Fukuoka Prefecture (72) Akira Sakurai 13-21, Yusentei, Jonan-ku, Fukuoka City, Fukuoka F-term (reference) 3H078 AA02 AA26 BB07 BB11 BB13 CC02 CC44 CC52 CC73

Claims (9)

[Claims] 1. A wind speed increasing device comprising a long cylindrical wind body expanding from a wind inlet to an outlet, wherein the vicinity of the inlet is a wind power take-out position. 2. The wind speed increasing device according to claim 1, wherein a ratio of a length of the wind tunnel body to a diameter of the inlet is 0.5 or more. 3. An inflow guide piece having a curved surface opening outwardly at an edge of the inflow port.
The wind intensifier as described. 4. The wind speed-increasing device according to claim 1, further comprising a flange-like piece extending outward at an edge of the outlet. 5. The wind speed increasing device according to claim 1, wherein the wind tunnel body has a cylindrical shape. 6. The wind speed increasing device according to claim 1, wherein the inclination angle of the side trunk portion with respect to the axis of the wind tunnel body is in a range of 2 to 5 °. 7. A wind power generator, comprising: the wind speed increasing device according to claim 1, wherein a wind turbine for power generation is arranged at a wind takeout position near the inlet. 8. The wind power generator according to claim 7, further comprising an opening / closing port for introducing wind outside the wind tunnel at a side trunk portion of the wind tunnel. 9. The wind power generator according to claim 8, further comprising means for detecting a flow velocity of the wind flowing into the inflow port, and control means for opening the opening / closing port when the flow velocity is equal to or higher than a set value.