JPH09112406A - Sail for windmill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To convert wind power energy into electric power energy, etc., in a wide range of wind velocity. SOLUTION: Plural sets of sail units 4, each of which consists of at least two plate-like stocks 4a, 4b, are radially mounted to the periphery of a rotary shaft 3 of a windmill at equal angles. The flow of a wind blowing from the front into between the stocks 4a, 4b, which is a laminal flow in the upstream zone, develops into a turbulent flow in the downstream zone, and the boundary between the laminar flow and the turbulent flow is moved to the upstream with increasing the wind velocity. Thus, the wind receiving surfaces of the stocks 4a, 4b of the plural sets of the sail units 4 are inclined respectively at different angles to each other and in the same direction as the plane of rotation in order that the rotation of the sail unit 4 is suppressed by the grown turbulent flow to produce the decelerative effect when the wind velocity exceeds a constant value.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a wind turbine blade capable of stably converting wind energy into electric energy or the like in a wide wind speed range from low wind speed to high wind speed.

[0002]

2. Description of the Related Art A conventional wind turbine blade has a plurality of blades radially attached to a rotating shaft at equal angular intervals, of which the wind energy is taken out at a low wind speed and converted into power energy or the like. In order to increase the size of the wind receiving surface, the blade area per blade is increased or the number of blades is increased so that the wind energy is taken out at a high wind speed. We respond by reducing the area of the blades per sheet or by reducing the number of blades.

The above-mentioned blades for low wind speed are designed to prevent damage to equipment against strong winds such as gusts and typhoons, in order to brake the blades, change the angle of the blades, and enlarge the wind receiving surface. It is necessary to remove the seat blades, etc. provided in the above, and the blade for high wind speed does not have any problem at high wind speed, but at low wind speed the blade does not rotate and wind energy cannot be extracted. At present, there is a problem that there is no wind turbine blade that can stably convert wind energy into electric energy over a wide wind speed range from low wind speed to high wind speed.

[0004]

The problem to be solved by the invention is that the above-mentioned conventional blades for a wind turbine function only in a narrow wind speed range, and the wind energy is stable over a wide wind speed range from low wind speed to high wind speed. The present invention has solved the above-mentioned problems, and starts to rotate at a low wind speed, the rotation speed is substantially constant even at a high wind speed, is not significantly affected by the weather, and is wide. A blade for a wind turbine capable of stably converting wind energy into electric energy or the like in a wind speed range.

[0005]

According to the present invention, a plurality of sets of blade units 4 composed of at least two plate-like ribs 4a and 4b arranged in parallel so as to maintain a predetermined interval in a rotation direction are installed in a wind turbine. Radially attached around the rotary shaft 3 at equal angular intervals, and the flow of wind flowing from the front face between the skeletons 4a and 4b is laminar in the upstream region, but develops into turbulence in the downstream region, and the wind speed As the boundary between the laminar flow and the turbulent flow moves to the upstream side with an increase in the wind velocity, and when the wind speed exceeds a certain value, the developed turbulent flow suppresses the rotation of the blade unit 4 to start the deceleration effect. Lamb 4a, 4 of the blade unit 4
A wind turbine blade in which the wind receiving surfaces of b are inclined at the same direction and different angles with respect to the rotating surface, whereby the wind turbine starts to rotate even at a low wind speed, and the rotational speed is substantially even at a high wind speed. It is constant, the rotation of gusts, typhoons, etc. is suppressed and the mechanical part is not damaged, it is not greatly affected by the weather and it is possible to stably convert wind energy into electric energy etc. in a wide wind speed range. Is.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. 1 to 3. Reference numeral 1 is a tower, and 2 is a wind turbine installed in the tower 1, which is configured as follows. That is, 3 is a rotary shaft, 4 is a plurality of blade units radially attached to the periphery of the rotary shaft 3 via mounting brackets 4k at equal angular intervals, and arranged in parallel so as to maintain a predetermined interval in the rotational direction. It is composed of at least two plate-like ribs 4a and 4b. 5 is a rib.

Explaining the blade unit 4 in more detail, the flow of wind flowing from the front between the ribs 4a and 4b is laminar in the upstream region, but develops into turbulence in the downstream region.
Moreover, as the wind speed increases, the boundary between the laminar flow and the turbulent flow moves to the upstream side, and when the wind speed exceeds a certain value, the developed turbulent flow suppresses the rotation of each blade unit 4 and decelerates in the opposite manner as compared with the normal case. In order to start, the wind-receiving surfaces of the ribs 4a and 4b of the plurality of sets of blade units 4 are inclined at the same direction and different angles with respect to the rotation surface (perpendicular to the wind direction) (see FIG. 2). .

The material of the ribs 4a, 4b and the mounting bracket 4k is not particularly limited as long as it is lightweight, is resistant to rust, and can withstand high wind speeds. A is the distance between the lamellas 4a and 4b, Ba and Bb are the widths of the lamellas 4a and 4b, α,
β is the inclination angle of the lamina 4a and 4b with respect to the wind direction, and θ
Is a rotating surface of the front end surface of the blade unit 4 (correctly, a virtual surface connecting the front ends of the ribs 4a and 4b) (the surface of the mounting bracket 4k)
It is an inclination angle with respect to, and is determined in consideration of the strength of the material, the output, the braking action of turbulent flow on rotation described later, and the like. Note that X is the wind direction, and R is the rotation direction of the blade unit 4. Further, the calves forming one set of blade units are not limited to two as described above, but can be increased as necessary.

In FIG. 3, assuming that the wind turbine rotational speed when there is no braking action at wind speed V ₀ is N ₁ and the decelerating wind turbine rotational speed based on braking is N ₂ , the wind turbine rotational speed of the present invention is (N _1- N ₂ ).

[0010]

As described above, in the vane unit 4 of the present invention, the flow of the wind flowing from the front to the ribs 4a and 4b is laminar in the upstream region but develops into turbulent flow in the downstream region. Moreover, the boundary between the laminar flow and the turbulent flow moves to the upstream side as the wind speed increases (the laminar flow region becomes shorter, the turbulent flow region becomes longer accordingly, and the drag force against the blade unit increases). Moreover,
When the wind speed exceeds a certain value, the developed turbulence increases the braking action, the rotation of the blade unit 4 is suppressed, and the deceleration starts (see FIG. 3).

Since the present invention is constructed as described above, it starts to rotate at a low wind speed, the rotation speed is substantially constant even at a high wind speed, the rotation of gusts, typhoons, etc. is suppressed and the mechanical parts are not damaged. , It is possible to stably convert wind energy into electric energy, etc. over a wide wind speed range without being much affected by weather.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an example of a blade unit of the present invention.

FIG. 3 is a relationship diagram showing the operation of the present invention.

[Explanation of symbols]

 1 Tower 2 Windmill 3 Rotating shaft 4 Blade unit 4a Lamb 4b Lamb 4k Mounting bracket 5 Rib A Lamb spacing Ba Lamb width Bb Lamb width R Rotation direction X Wind direction α Angle of inclination of the angle of the vertebral β Direction of the angle of the vertebral Inclination angle θ Inclination angle of front end face of blade unit

Claims (1)

[Claims] 1. At least two plate-like lamellas (4a, 4b) arranged in parallel so as to maintain a predetermined interval in the rotational direction.
A plurality of sets of blade units (4) consisting of are attached radially around the rotary shaft (3) of the wind turbine at equal angular intervals, and the wind flow from the front surface to the ribs (4a, 4b) flows in the upstream region. Although it is a laminar flow, it develops into turbulent flow in the downstream region, and the boundary between laminar flow and turbulent flow moves to the upstream side as the wind speed increases. Lambs (4a, 4a) of the plurality of sets of blade units (4) so that the rotation of the unit (4) is suppressed and the deceleration effect starts.
Wind turbine blades in which the wind-receiving surface of b) is inclined at different angles in the same direction with respect to the rotating surface.