WO2019111674A1

WO2019111674A1 - Vertical axis-type wind turbine

Info

Publication number: WO2019111674A1
Application number: PCT/JP2018/042486
Authority: WO
Inventors: 裕寺尾
Original assignee: 裕寺尾; 寺尾進
Priority date: 2017-12-06
Filing date: 2018-11-16
Publication date: 2019-06-13
Also published as: JP2019100289A

Abstract

Provided is a vertical axis-type wind turbine which provides extremely high energy conversion efficiency exceeding the performance of a known high-efficiency vertical axis wind turbine in which blades are subjected to heaving motion. The vertical axis-type wind turbine 1 is provided with blades 5 which rotate around a vertically mounted rotating shaft 2, wherein, by means of a heaving motion providing mechanism, the blades 5 rotating around the rotating shaft 2 are subjected to rotating orbital motion other than that of a circular orbit, and, during rotating orbital motion of the blades 5, at least the blades 5 are subjected to a pitching angle varying operation for varying the pitching angle of the blades.

Description

Vertical axis wind turbine

The present invention relates to a wind turbine, and more particularly to a vertical axis wind turbine whose rotation axis is perpendicular to the ground which can efficiently convert natural energy into electric energy and the like.

A horizontal axis wind turbine is affected by the wind direction, while a lift-type vertical axis wind turbine is a wind turbine for wind power generation that is suitable for environments where the wind direction is variable, with wind in any direction available and having no dependence on the wind direction. is there. The vertical axis wind turbine need not be specially controlled in attitude according to the wind direction, and can be installed at a position close to the ground, so that it can be easily handled during installation and maintenance, and can be miniaturized.

In a typical vertical axis wind turbine, blades are connected by rods so as to be parallel to a vertically installed rotation shaft, and the radius of the wind turbine, that is, the rotation radius of the blades is fixed (Patent Document 1). For this reason, it is necessary to provide a specification of structure and strength that can withstand the wind speed exceeding the cut-out wind speed, and the entire weight and friction also require a rotational force under high wind speed. For this reason, the conventional lift-type vertical axis wind turbine has a small moment for rotating the wind turbine under low wind speed, and it is difficult to obtain the starting torque of the wind turbine under the low wind speed for the same reason and can not start Problem is pointed out.

In order to solve such a problem, in a vertical axis type wind turbine for lifting power type wind turbine having a fixed shaft installed vertically, a rotation shaft rotating around it, and a blade arranged parallel to the rotation shaft, Support arm that connects the shaft and the rotation shaft and supports the blade to extend and contract in the radial direction centering around the rotation shaft and moves the blade in parallel, and the blade is always urged radially outward to make the blade support arm radially outward When the force to radially inward the blade is greater than the force to bias the blade radially inward by using the centrifugal force when the blade is rotated while urging the blade radially inward while pushing the blade radially outward. A biasing means for radially contracting the wing support arm inward, and at least at the start-up, the wing support arm is extended radially outward at least at the start-up to expand the blade's radius of rotation to the maximum radius and wind turbine radius Maximize the centrifugal force when the windmill starts to rotate Ri shortens the blade support arm radially inward, have been developed techniques to reach the cut-in wind speed at least until the wing rotation radius is minimized (Patent Document 2). However, even with such a technology, it is far from being able to achieve the fundamental efficiency improvement of the vertical axis wind turbine.

Therefore, as shown in Non-Patent Document 1, a vertical axis wind turbine is provided with a wing mechanism for flapping (heaving), and while a normal vertical axis wind turbine blade movement locus draws a circle, it is made not to follow a circular orbit on the wing. Vertical axis wind turbines have been proposed to improve their performance.

An example of motion control that gives a heaving motion to the blades of a vertical axis wind turbine can employ a simple and efficient transmission mechanism using a combination of a pair of gears and a scotch yoke. This is a simple mechanism and high mechanical transmission efficiency. Verification by numerical calculation in the range of blade linear theory shows that a performance improvement of 15% or more can be expected compared to a normal vertical axis wind turbine It is done.

JP 2005-171852 A (page 5, FIG. 1) JP-A-2015-197093 (page 6, FIG. 2)

An object of the present invention is to provide a vertical axis wind turbine capable of exhibiting extremely high energy conversion efficiency, which further exceeds the performance of a high efficiency vertical axis wind turbine in which a blade is known to have a heaving motion.

In order to solve the above problems, the vertical axis wind turbine of the present invention is
A vertical axis wind turbine having blades rotating about a rotation axis installed vertically, comprising:
A heaving motion imparting mechanism imparts a rotational orbit motion other than a circular orbit to the wing pivoted around the rotation axis, and at the time of the rotational orbit motion of the wing, the wing pitching angle changes with respect to at least the wing It is characterized in that the pitching angle changing operation is given.
According to this feature, the stall characteristics in the range beyond the linear wing theory of an actual wing can exhibit energy conversion efficiency exceeding the performance of a highly efficient vertical axis wind turbine in which the wing is given a heaving motion. That is, by considering the non-linear characteristics of the blade, it is possible to exhibit the highest performance among vertical axis wind turbines in which the blade is given a heaving motion.

The vertical axis wind turbine of the present invention is
An arm extending from the rotation shaft and the wing are pivotally supported, and the wing can rotate relative to the arm.
According to this feature, since the wing rotates relative to the arm rotating with the shaft within a predetermined range, it is possible to effectively move the heaving movement and the pitching angle changing operation.

The vertical axis wind turbine of the present invention is
An elastic return means is interposed at a connection portion between the rotation shaft and an arm portion for supporting the wing.
According to this feature, since the rotating wing is subjected to centrifugal force and repeated expansion and contraction due to the action of the elastic return means due to the change of the distance between the rotation axes, the relative inflow angle and the optimum flow angle automatically for the rotor Relative inflow rates can be generated.

The vertical axis wind turbine of the present invention is
The elastic return means interposed at the connection between the rotation shaft and the arm supporting the wing is characterized in that it is a spring having strength and performance optimum for wing attack angle control.
According to this feature, it is possible to automatically generate the optimum relative inflow angle and relative inflow velocity for the rotor with a simple spring structure. Furthermore, energy loss is small because no special power source is required.

The vertical axis wind turbine of the present invention is
A connection portion between the rotation shaft and an arm portion for pivotally supporting the wing is characterized in that it is disposed on the head position side of the wing.
According to this feature, since the change of the blade pitching angle is started from the leading direction of the blade, the swing width of the blade is increased, and the relative inflow angle and the relative inflow velocity are automatically generated in the rotary blade. Can.

The vertical axis wind turbine of the present invention is
It is characterized in that the rotation orbit motion other than the circular orbit is a orbit formed by combining the orbit whose rotation diameter changes with the rotation around the rotation axis and the pitching angle change operation.
According to this feature, it is possible to obtain wing vibrational motion represented by the flight by the wing of a bird and the movement of the tail of an aquatic organism, and to generate the maximum efficiency with the minimum energy.

It is a figure which defines the azimuth of a vertical axis type windmill. It is a figure which shows the blade thrust of a vertical axis windmill. It is a figure which shows the rotation track of a vertical axis type windmill. It is a conceptual diagram showing the drive mechanism of the vertical axis type windmill concerning the present invention. It is a figure which shows the wing | blade Heaving movement generation | occurrence | production mechanism by a planetary gear. (A), (b) is a figure which shows the drive mechanism of the vertical axis type windmill which concerns on this invention. It is a figure which shows the drive mechanism of the vertical axis type windmill using a parallel link. (A) is a conceptual diagram which shows blade motion axisymmetric to the rotation axis, (b) is a conceptual diagram which shows blade motion axisymmetric to the rotation shaft. (A) is a figure which shows a connection with the rotating shaft and the arm part which supports a wing | wing, (b) is a figure which attached the thrust increase Flap structure with respect to the up-down motion of an arm to a wing tip. It is a conceptual diagram which shows the dynamic control mechanism of wing Heaving movement. It is a modification which shows arrangement of an actuator, and (a) is a figure showing a combination of a bevel gear and a link mechanism, and (b) a spur gear.

EMBODIMENT OF THE INVENTION The form for implementing the vertical axis type windmill concerning this invention is demonstrated below based on an Example.

A vertical axis wind turbine according to an embodiment will be described with reference to FIGS. 1 to 11. First, reference numeral 1 in FIG. 1 is a vertical axis wind turbine to which the present invention is applied.

Vertical Axis Wind Turbine (VAWT: Vertical Axis Wind Turbine) can generate power regardless of the wind direction compared to Horizontal Axis Wind Turbine (HAWT: Horizontal Axis Wind Turbine), and install the generator part near the ground In addition to achieving a low center of gravity, it has the advantages of low manufacturing and maintenance costs and easy installation and transportation.

However, the efficiency of the vertical axis wind turbine is said to be lower than that of the horizontal axis wind turbine. One of the factors is a factor relating to performance degradation when the blades of a vertical axis wind turbine rotate and face the wind. As shown in FIGS. 1 and 2, the blade does not generate any rotational torque near the azimuth angle θ = 0 ° of the wind direction, and conversely generates only a resistance component in the rotational direction. It becomes a negative factor to the occurrence.

More specifically, as shown in FIG. 2, in the vertical axis wind turbine, the rotational torque increases according to the direction in which θ increases (the area on the windward side of the blade: θ = 0 to 90 °), and around θ = 90 ° The maximum value of torque is then taken, and thereafter the generated torque decreases, and once at θ = 180 °, it takes a negative extreme value. Further, as θ increases, the torque output gradually recovers, and becomes a local maximum at around 259 ° to 270 °, and thereafter takes a minimum value at θ = 360 °. In practice, the generated torque of 0 to 180 ° is larger than the generated torque at the blade position of 180 ° to 360 °. This is considered to be the effect of the release vortex.

The vertical axis wind turbine 1 (FVAWT: Pitch Angle Controlled Vertical Winding Vertical Axis Wind Turbine) according to the present invention is defined as a wind turbine having a wing driving mechanism that heaving as described later. Therefore, as shown in FIG. 3, the blade 35 of the normal vertical axis wind turbine draws a circular orbit C at the rotation axis center, but the wing 5 of the vertical axis wind turbine according to the present embodiment does not draw a circular orbit. It may be rephrased as a system for drawing a pivoting track D other than a circular track.

(Number of blades of vertical axis wind turbine)
The number of blades of the vertical axis wind turbine 1 is not particularly limited, but an even number is a basic form. This is because we considered the function and structure to cancel the centrifugal force generated by the wing when performing rotational movement around the rotation axis of the vertical wing. If blade motion control is not performed to balance the centrifugal force generated by each blade with respect to the rotation axis, the burden on the shaft system increases, which affects the reliability of the shaft system and the entire system.
Therefore, in the vertical axis wind turbine 1, by making the normal motion of the swinging motion of the opposing blades equal to the distance between the shaft and the blades, the centrifugal force generation is canceled between the two opposing blades, or the opposing two blades are Minimize the difference in force acting on the central axis of rotation of centrifugal force acting on each other.

(Drive mechanism of vertical axis wind turbine)
The drive mechanism 10 of the vertical axis wind turbine 1 adopts a simple mechanism as shown in FIG. This is to minimize energy losses given product cost and transfer efficiency. As shown in FIG. 5, in the proposed example of the drive mechanism 10, a pair of

planetary gears

12, 12 disposed concentrically with the rotation shaft 2 and meshed with a sun gear 11 fixed to the ground is scotch as an actuator 15. Attach a yoke, and when the

blades

5, 5 of the vertical axis wind turbine 1 rotate automatically, with the hinge portion 4 interposed between the upper ends of the

blades

5, 5 and the arm portion 3 as the base end, in the centrifugal force operating direction The wing position is a mechanism that expands and contracts with the wings 5 'to 5-5''(see FIG. 4). A link mechanism is adopted as the flapping generation mechanism of the wing. Other than this, a mechanism for changing the blade turning trajectory using a motor system and a hydraulic actuator, or a mechanical system using a slider system is also conceivable. However, considering the cost and the energy transfer coefficient in any case, it is considered that a system adopting the link mechanism according to the present embodiment is advantageous.

As a result, three control variables that are not included in the normal vertical axis wind turbine are added to the blade Heave motion control.
a) Heaving Amplitude (The amplitude of Heave)
b) Frequency (Heaving vibration frequency)
c) Phase Lag (phase difference to start movement)

The performance of the vertical axis wind turbine 1 is determined by using the optimum combination of these variables. Further, since it is more efficient to carry out the Heaving motion of the wing 5 in parallel with the rotation axis 2 in the normal direction of the wing rotational motion, a parallel link method capable of controlling the wing motion is adopted. The centrifugal force direction In / Out of the wing adopts a gear and link system as shown in FIGS.

(Motion of the wing of a vertical axis wind turbine)
Considering that the positional relationship between the rotation axis and the blades is parallel, as shown in FIGS. 7 and 8A, the relative positions of the two

blades

5 and 5 which form the basis of the vertical axis wind turbine 1 are as follows: The wing movement is axisymmetric to the rotation axis 2 and the

wings

5 and 5 perform parallel movement, or as shown in FIG. 8 (b), the wing movement is axisymmetric to the rotation axis 2 and the two

wings

5 and 5 are There are two possible mechanisms for performing the seesaw motion according to the mounting

arms

14 and 14 and for the

wings

5 and 5 to perform the parallel motion.

In energy absorption from the flow field, which energy absorption efficiency does not differ much, but in FIG. 8 (a), the reaction force by moving the blade up and down works as a force to vibrate the rotation axis up and down, and In (b), no force is generated by the vertical motion of the wing. Therefore, practically, the system of FIG. 8 (b) is considered to be advantageous.

(Pitching control of the wing of PACFVAWT)
The relative inflow angle and the relative inflow velocity of the VAWT are determined by the flow velocity U and the blade trajectory radius r and the circumferential velocity ratio TSR. However, in FVAWT, the relative inflow angle to the rotating wing and the relative flow velocity can be arbitrarily set by changing the wing control variable.

Therefore, heaving motion control of the wing is performed to increase the relative inflow angle, and the relative wing angle is set in advance so that the relative angle of attack becomes optimum (stall angle limit) with a simple mechanism (Pitch Spring). High energy absorption efficiency can be exhibited by carrying out. In addition, it is also possible to adopt various actuators in this blade angle control part and actively control the blade angle to aim at higher performance.

As with FVAWT, PACFVAWT has three blade control parameters, so the optimum combination of variables can not be determined simply. PACFVAWT is a high-performance FACFVAWT constructed by setting optimal values of control variables derived as a result of many numerical calculations and new optimal Pitch Spring.

Furthermore, the cycloidal wing control system shown in FIG. 2 arranges a complicated link mechanism in the VAWT, and exhibits performance beyond the VAWT for the first time. However, in this system, it is shown by numerical calculation that wing Pitch angle control is simple passive type, and it is far simpler than cycloidal type, and it exhibits performance beyond these.

Rotor blades 5 of FVAWT and PACFVAWT can control large inflow blade attack angle and relative inflow velocity. Therefore, the wing 5 can also operate beyond the stall region. As shown in FIGS. 9 (a) and 9 (b), a spring 16 (Pitch Spring) as an elastic return means is disposed at the wing joint, and the relative inflow angle is passively controlled to obtain an optimum relative inflow. Create a wing angle. This mechanism is also applicable to FVAWT.

The pitch angle control spring of the wing 5 employs a spring 16 having the strength and performance optimum for wing attack angle control. The motion phase of the wing 5 of FVAWT and PCFVAWT has an optimum value. Therefore, it has an optimal wind direction holding mechanism that corresponds to the wind vane with respect to the wind direction.

As shown in FIG. 9 (b), a mounting arm having a function of joining the wing 5 and the rotary shaft 2, resisting the centrifugal force caused by the wing rotation, and converting the thrust of the wing 5 into torque and transmitting it to the rotary shaft 2 The cross section 18a of the portion 18 is provided with an optimal two-dimensional symmetrical wing cross section, or a thrust increasing mechanism 19 which increases the thrust generation of the arm. Since the arm 18 moves up and down while rotating, it behaves like fluttering motion, so the thrust generation in this operation is aimed and the wing cross section 18a and the thrust generating function are incorporated.
The plane shape of the arm portion 18 is a wing plane shape highly efficient for thrust generation with respect to the vertical movement of the arm, and is a thruster system with higher efficiency.

Although all the above described the passive Heaving / Flapping motion of the wing, as a modification of the present invention, as shown in FIG. 10, the Heaving / Flapping motion is active by arranging the electric actuator (rotational angle servo). The way to do it is also conceivable. The use of an electric actuator requires drive energy of the motor. However, FVAWT / FACFVAWT is expected to have much larger energy gain from the flow field than VAWT. Therefore, it can be judged that the energy balance is sufficiently positive, and a simple control system for active control is proposed.

FVAWT / PACFVAWT needs to perform frequency control and phase difference control of motion Heaving (Flapping) of the rotor. However, using one actuator completes the entire system. The actuator control in this case will be described. As shown in FIG. 10, the flow direction and the flow velocity, which are control condition variables, are measured using the measuring meter 21, and the actuator 23 is angularly controlled by the control device 20. It suffices to operate the mechanism for expanding and contracting 5. That is, the control device 20 detects a flow velocity / flow direction which is a control condition, and outputs a rotation angle instruction command of the actuator 23.

If a flow direction / flow velocity meter adopts an ultrasonic flow velocity meter, it is enough with one sensor system. In FIG. 10, rotation angle control by one servomotor 22 is shown as the rotation angle control means. In a system in which the two blades move up and down symmetrically around the rotation axis, two servomotors may be used.

Let's consider FVAWT and PACFVAWT that become Active control. This is at the same time a system that satisfies the directionality of the system with respect to the wind direction. As shown in FIG. 11 as another modified example of the present invention, the actuator is disposed away from the generator body 6 of the rotating body. In addition, expansion and contraction of the wing can be automatically performed even if the actuator 15 is fixed without being rotated, and further the following can be achieved.
1) Low center of gravity 2) Small moment of inertia

Also, with this arrangement, the actuator drive signal can be freely given from the ground. If the actuator is attached directly to the rotating part, signals from the slip ring etc. and their drive energy supply are required, and the wiring and equipment become complicated. However, in the arrangement of FIG. 11 (a), the area resistance portion slightly increases due to the wind direction as compared with FIG. 11 (b).

In addition, although not shown in the drawings, it is possible to construct a system that achieves both Passive Controlled and Active Controlled by the combination of two bevel gears and the combination of a spur gear and an external stepping motor and spur gear. More specifically, high performance can be exhibited by rotating the stepping motor at an angle to the rotation axis and adjusting the phase of the seesaw motion start position of the wing to the wind direction. By stopping the gear when it is in the optimal phase position, the system rotates with wind power and the wing performs flapping motion with seesaw motion. This can be said to have had a performance that surpasses the performance of the wind vane.

(Effect of the present invention)
According to the vertical axis wind turbine 1 of the present invention described above, the heaving motion imparting mechanism gives the wing 5 rotating about the vertical axis a rotational orbital motion other than a circular orbit, and causes the wing 5 to rotate. At the time of orbital movement, at least the wing 5 is provided with a pitching angle changing operation in which the wing pitching angle changes, so that the stall characteristics in the range beyond the linear wing theory possessed by the actual wing 5 It is possible to exhibit energy conversion efficiency that exceeds the performance of a highly efficient vertical-axis wind turbine with a heaving motion given to 5. That is, by considering the non-linear characteristics of the blade, the highest performance can be exhibited among vertical axis wind turbines in which the blade 5 is given a heaving motion.

Further, an arm extending from the rotation shaft 2 and the wing 5 are pivotally supported, and the wing 5 can rotate relative to the arm so that the arm rotating with the rotation shaft 2 can be rotated. Since the wing 5 is relatively rotated within a predetermined range, it is possible to make it possible to effectively combine the heaving movement with the pitching angle changing movement.

Further, by interposing an elastic return means at the connecting portion between the rotary shaft 2 and the arm portion for supporting the wing 5, centrifugal force acts on the rotating wing 5 due to the change of the distance between the rotary shafts 2 and further elastic. Since the expansion and contraction is repeated by the action of the return means, it is possible to automatically generate the optimum relative inflow angle and relative inflow velocity for the rotor.

Furthermore, since the elastic return means interposed at the connection between the rotary shaft 2 and the arm supporting the wing 5 is the spring 16 having the strength and performance optimum for wing attack angle control, it has a simple spring structure. It is possible to automatically generate the optimum relative inflow angle and relative inflow velocity for the rotor. Furthermore, energy loss is small because no special power source is required.

In addition, since the connection between the rotary shaft 2 and the arm that pivotally supports the wing 5 is disposed on the head position side of the wing 5, the change of the wing pitching angle is started from the head direction of the wing 5 As the swing width of the wing 5 increases, it is possible to automatically generate the relative inflow angle and the relative inflow velocity optimum for the rotor.

In addition, because the orbit other than the circular orbit is an orbit combining the orbit whose rotation diameter changes with the rotation around the rotation axis 2 and the pitching angle change operation, the flight by the wing of the bird and the aquatic life The wing oscillation movement represented by the movement of the tail fin of a living being is obtained, and the maximum efficiency can be generated with the minimum energy.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and any changes or additions may be made without departing from the scope of the present invention. Be

Reference Signs List 1 vertical axis wind turbine 2 rotary shaft 3 arm 4 hinge 5 wing 6 generator main body 10 drive mechanism 11 sun gear 12 planetary gear 14 arm 15 actuator 16 spring 18 arm 19 thrust increasing mechanism 20 control device 21 measuring meter 22 Servo motor 23 actuator

Claims

A vertical axis wind turbine having blades rotating about a rotation axis installed vertically, comprising:
A heaving motion imparting mechanism imparts a rotational orbit motion other than a circular orbit to the wing pivoted around the rotation axis, and at the time of the rotational orbit motion of the wing, the wing pitching angle changes with respect to at least the wing A vertical axis wind turbine characterized by providing a pitching angle changing operation.
The vertical axis wind turbine according to claim 1, wherein an arm extending from the rotation shaft and the wing are pivotally supported, and the wing can rotate relative to the arm. .
The vertical axis wind turbine according to claim 1 or 2, wherein an elastic return means is interposed at a connection portion between the rotation shaft and an arm portion for pivotally supporting the wing.
The elastic return means interposed at the connecting portion between the rotation shaft and the arm supporting the wing is a spring having strength and performance optimum for wing attack angle control. Vertical axis windmill.
The vertical axis wind turbine according to any one of claims 1 to 4, wherein a connecting portion between the rotation shaft and an arm portion for pivotally supporting the wing is disposed on a leading end side of the wing.
The turning orbit motion other than the circular orbit is a orbit obtained by combining the orbit whose turning diameter changes with the turning around the rotation axis and the pitching angle changing operation. Vertical axis wind turbine according to any of the above.