JP2922722B2 - Windmill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wind turbine.

[0002]

2. Description of the Related Art Conventionally, in wind turbine power generation, two blades, three blades,
Windmills with propeller-shaped wings such as single blades have been used. As a wind turbine used for power such as pumping, a multi-blade wind turbine has been mainly used.

[0003]

However, in the above-described wind turbine having the propeller-type blades, the rotation speed is large and suitable for power generation, but the obtained torque is small. In addition, there is a problem that the wind turbine does not rotate under a low wind speed when the starting wind speed becomes relatively high.

On the other hand, in a multi-blade wind turbine, the starting wind speed is small and a large torque can be obtained, but the rotation speed is small. However, as long as the torque is sufficiently large, it can be transmitted to the generator at a predetermined rotational speed by mechanical acceleration.

[0005] Further, the airfoil of the conventional windmill, which is considered to be efficient, has a shape close to the shape represented by the airfoil of an aircraft. That is, as shown in FIGS. 9 and 10, the portion near the leading edge b of the wing a was made thick and gradually became thinner toward the trailing edge c. Conventional wind turbines having such wings have utilized wing lift described by Bernoulli's theorem.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a wind turbine capable of increasing the wind turbine efficiency and increasing the obtained torque more than the conventional one without lowering the peripheral speed ratio, which is the ratio of the peripheral speed of the blade to the wind speed. With the goal.

[0007]

In order to achieve the above-mentioned object, a wind turbine according to the present invention comprises a first point connecting a first point and a second point.
Drawing a line segment, drawing a second line segment at a predetermined angle from a first midpoint of the first line segment, and a first intersection between a first perpendicular line set at the second point and the second line segment; A second perpendicular is drawn from a second midpoint of a third line segment connecting the first midpoint and the second perpendicular,
A straight line that passes through the first middle point of the first line segment and is orthogonal to the first line segment;
A first arc having a fourth line segment as a radius is drawn around the second intersection point, and a fifth line segment is drawn at a predetermined leading edge angle with respect to the first line segment. Third with the straight line
A third perpendicular is drawn from a third midpoint of a sixth line connecting the intersection and the first intersection, and a radius is a seventh segment centered on a fourth intersection between the third perpendicular and the straight line. A second arc is drawn, and an eighth line segment that is in contact with the second arc and is parallel to the fifth line segment is drawn. The first point, the fourth perpendicular line set at the first point, and the eighth line A small arc connecting the fifth intersection with the line segment is drawn, and a ninth line segment connecting the fifth intersection with the contact point between the second arc and the eighth line segment and the ninth line connecting the fifth intersection with the fifth intersection point. A third arc continuing to the line segment, the first arc, a tenth line segment connecting the first midpoint and the first point, and the small arc are formed, and the ninth line segment and the A plurality of blades having a cross-sectional shape surrounded by three arcs, a first arc, a tenth line segment, and a small arc are radially provided.

Further, the wind turbine according to the present invention has a first point and a second point.
A first line segment connecting the points is drawn, a second line segment is drawn at a predetermined angle from a first midpoint of the first line segment, and a second line segment between the first perpendicular line set at the second point and the second line segment is drawn. A second perpendicular line is drawn from a second midpoint of a third line segment connecting the one intersection and the first midpoint, and passes through the first midpoint of the first line segment and is orthogonal to the second perpendicular line. Draw a first arc having a fourth segment as a radius around the second intersection of the straight line and a fifth segment with a predetermined leading edge angle with respect to the first segment. A third perpendicular line is drawn from a third midpoint of a sixth line segment connecting the third intersection point between the line segment and the straight line and the first intersection point, and a fourth intersection point between the third perpendicular line and the straight line is centered. Draw a second arc having a radius of the seventh line, draw an eighth line in contact with the second arc and parallel to the fifth line, and draw the first point and the first point The fourth A fifth intersection point between the line and the eighth line segment,
A ninth line segment connecting the contact point between the second arc line and the eighth line segment and the fifth intersection point, and a third arc line connected to the ninth line segment at the contact point. , The first arc,
A tenth line segment connecting the first middle point and the first point and the small arc are formed, and the ninth line segment, the third arc, the first arc, the tenth line segment, and the small arc are formed. A main wing having an enclosed cross-sectional shape, and having the same curved surface as the wind receiving surface which is disposed substantially parallel to the main wing with a predetermined interval and a predetermined shift width and includes the first arc and the tenth line segment of the main wing. A plurality of double wings having substantially uniform and thin sub wings are radially provided.

[0009]

In the wind turbine of the present invention, the ninth cross section of the wing
The surface corresponding to the line segment is a flat surface. If a slight opening angle is set between the surface corresponding to the ninth line and the airflow flowing from the leading edge side of the blade, a negative pressure is generated on the surface corresponding to the ninth line. . Then, the negative pressure is applied to the lift described by Bernoulli's theorem, and the obtained torque increases.

[0010] In the case of a double wing having a main wing and a sub-wing arranged substantially parallel to the main wing, the lift of the sub-wing is further added to the lift of the main wing which is increased in the same manner as described above.
Greater torque can be obtained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments.

FIG. 3 shows an embodiment of the wind turbine according to the present invention. Reference numeral 1 denotes a wind turbine that is rotatable around an axis L. The wind turbine 1 includes a plurality of blades 3 in a direction orthogonal to the axis L in a radial manner.

That is, the base ends of the multiple blades 3 are fixed radially at a predetermined pitch along the outer peripheral surface of the shaft portion 2 rotatably held around the axis L.

Although not shown, the shaft portion 2 is connected to a generator or the like via a gearbox having a plurality of gears or the like.

The double wing 3 has a main wing 4 and a sub wing 5 arranged on the wind receiving surface 6 side of the main wing 4.

In other words, as shown in FIG. 1, the main wing 4 has a maximum thickness in a cross-sectional shape slightly from the front-rear intermediate portion to a portion near the rear edge 10, and the front half gradually becomes thinner forward. It is tapered, and in the latter half, it becomes gradually thinner rearward and concavely curved toward one side. One side of the concavely curved surface is the wind receiving surface 6.

Specifically, the cross-sectional shape of the main wing 4 is
Set as shown below.

That is, as shown in FIG. 2, a first line segment XX 'connecting the first point X and the second point X' is drawn, and the first line segment XX 'is drawn.
A second line segment OP is drawn from the first middle point O at a predetermined angle ρ.

From the second middle point E of the third line segment OQ connecting the first intersection point Q between the first perpendicular line H and the second line segment OP set at the second point X 'and the first middle point O. A second perpendicular I is drawn.

A second intersection point O ₁ between the second perpendicular line I and a straight line YY ′ passing through the first middle point O of the first line segment XX ′ and crossing at right angles.
The first arc OQ having a fourth line segment OO ₁ as a radius around the center
pull.

Further, a fifth segment XR is drawn at a predetermined leading edge angle ψ with respect to the first segment XX ′, and a third intersection S between the fifth segment XR and the straight line YY ′ and a first intersection Q, a third perpendicular J is drawn from a third midpoint F of a sixth segment QS connecting the
The around the fourth intersection point O ₂ of the perpendicular line J and the straight line YY '7
A second arc QST having a radius of the line segment SO ₂ is drawn.

An eighth line segment X ₁ R ₁ that is in contact with the second arc QST and is parallel to the fifth line segment XR is drawn, and a first point X is obtained.
The fourth perpendicular line K set at the first point X and the eighth line segment X ₁ R
A small arc VX connecting the fifth intersection V with ₁ is drawn.

Thus, the second arc QST and the eighth line segment X ₁
A ninth line segment UV connecting the contact point U and the fifth intersection V with R _1,
A third arc QSU continuous with the ninth segment UV at the contact point U,
A first arc OQ, a tenth line segment OX connecting the first middle point O and the first point X, and a small arc VX are formed.

Thus, the ninth line segment UV and the third arc Q
The shape surrounded by SU, the first arc OQ, the tenth line segment OX, and the small arc VX is the cross-sectional shape of the main wing 4 shown in FIG.

The main wing 4 formed as described above has a wind receiving surface 6 comprising a first arc OQ and a tenth line segment OX, a leading edge 8 comprising a small arc VX, a ninth line segment UV, 3 arc QSU
And a back surface 9 made of

The first half of the wind receiving surface 6 (corresponding to the tenth line segment OX) and the first half of the back surface 9 (corresponding to the ninth line segment UV) are flat surfaces.

In FIG. 1, δ ₁ is a blade angle at which the main wing 4 is inclined with respect to the rotation direction A. α is the angle of attack with respect to the airflow W ₂ flowing with the airflow angle φ with respect to the rotation direction A of the main wing 4.

The airflow W ₂ is generated when the main wing 4 rotates in the rotation direction A due to the wind W ₁ flowing at right angles to the rotation direction A from the wind receiving surface 6 side of the main wing 4. the rotational direction a flowing relatively to 4 which is the resultant force direction of the air flow between the air flow W ₃ and the wind W ₁ in the reverse direction.

The airflow angle φ, the angle of attack α, and the blade angle δ
₁ has a relationship of φ = α + δ ₁ . Further, it is preferable that the blade angle δ ₁ is appropriately changed along the longitudinal direction of the main wing 4. That is, in this case, the blade angle δ ₁ of the main wing 4 changes along the longitudinal direction, and the main wing 4 is twisted.

The predetermined leading edge angle ψ is determined by the airflow W ₂ and the main wing 4
Is set to have a slight (open angle) negative angle β between the back surface 9 and the first half surface (corresponding to the ninth line segment UV).

The sub wing 5 has substantially the same curved surfaces 7a and 7b as the wind receiving surface 6 of the main wing 4, and has a substantially uniform thickness.

The sub wings 5 are arranged substantially parallel to the main wing 4 with a predetermined interval N ₁ and a predetermined shift width N ₂ .

Specifically, the sub wing 5 is attached as follows.

That is, a line segment B ₁ that is parallel to the airflow W ₂ and passes through the trailing edge 10 of the main wing 4 is drawn.

Next, a perpendicular B ₂ is drawn from the leading edge 8 of the main wing 4 to the airflow W ₂ , and the intersection C between the line segment B ₁ and the perpendicular B ₂ is positioned at the leading edge of the sub wing 5. Further, the blade angle δ ₂ of the sub wing 5 is set to be the same as the blade angle δ ₁ of the main wing 4.

By arranging in this manner, the sub wing 5
, Together displaced by a predetermined shift width N ₂ in a direction parallel to the rotational direction indicated by arrow A relative to the main wing 4, and have a predetermined interval N ₁ in the direction perpendicular to the direction of rotation.

The predetermined interval N ₁ and the predetermined shift width N ₂
It is determined by the circumferential speed ratio, the predetermined interval N ₁ and the predetermined shift width N ₂ or more intervals and the shift width is set as described above is unnecessary.

As shown in FIG. 3, the length of each of the sub-wings 5 is approximately one half of the radius of the wind turbine, and is attached to the outer periphery of the wind turbine.

The peripheral speed ratio at the outer peripheral edge of the wind turbine 1 is 2
It is preferably set to at least 5 and at most 5, particularly preferably
The peripheral speed ratio is set to 3. Then, for example, the main wing 4 having a length of 1 m
Is 3, the peripheral speed ratio at the axis L is 0,
The peripheral speed ratio between the axis L and the tip is proportionally determined between 0 and 3.

The chord lengths M ₁ , M of the main wing 4 and the sub wing 5
₂ is progressively larger at the proximal end. In addition, the chord length was calculated by calculating the rigidity from the peripheral speed ratio.

Next, the use state of the wind turbine 1 of this embodiment (returning to FIG. 1) will be described.

The lift W described by Bernoulli's theorem is generated in the main wing 4 by the air flow W ₂ flowing at the air flow angle φ. Further, a negative pressure is generated on the back surface 9 side of the main wing 4 due to the negative angle β.

Further, the same lift as the wind receiving surface of the main wing 4 receives on the sub wing 5 is generated. Therefore, the lift D ₁ of the double wing 3 as a whole is the sum of the lift of the main wing 4, the negative pressure on the back surface 9 side thereof, and the lift of the sub wing 5.

D ₂ is a drag against the airflow W ₂ , and the double wing 3 is rotated by a resultant D ₃ of the drag D ₂ and the lift D ₁ . Specifically, the double wing 3 is rotated by a component force of the resultant force D _{3 in} the rotation direction A.

As described above, a negative pressure due to the negative angle β is applied to the lift of the main wing 4 described by Bernoulli's theorem, and a lift due to the sub wing 5 is applied to the double wing 3. can get. And the wind turbine efficiency per unit diameter {(rotational energy / wind energy) × 100 (%)} can be significantly increased.

Further, when the peripheral speed ratio is small, a large torque can be obtained. Therefore, it is sufficient to use a speed increaser composed of a plurality of gears for use in wind power generation.

Further, in the illustrated example, eight double blades 3 are provided. However, such a multi-blade type can reduce the starting wind speed of the wind turbine and rotate even in the case of a weak wind.

The double wings 3...
It is also preferable to use a plurality of sheets such as nine sheets or nine or ten sheets.

Next, an example of a method for manufacturing a wind turbine according to the present invention will be described.

First, the figure enclosed by the ninth line segment UV, the third arc QSU, the first arc OQ, the tenth line segment OX, and the small arc VX shown in FIG. , 1,2, ...
For each of the 16 positions, draw on cardboard, cut out this and make a pattern.

Then, the pattern papers are erected at predetermined intervals and arranged, and hardened with gypsum to form a prototype.

Next, a resin mold of an epoxy resin is made using the above-mentioned prototype, and the main wing 4 is duplicated with the epoxy resin using the resin mold.

After that, using a resin mold surface corresponding to the wind receiving surface 6 of the main wing 4, a release agent is applied to this surface and dried.
Three glass cloths are laminated and laminated, and hardened with epoxy resin to duplicate the sub wing 5.

The sub wing 5 is formed at a portion extending from the middle to the tip of the main wing 4 in the longitudinal direction.

The sub wing 5 is replaced with the sub wing 5 in FIG.
Attach it with the metal fittings 11 as shown in. During this installation,
The sub wings 5 are arranged substantially parallel to the main wing 4 with a predetermined interval N ₁ and a predetermined shift width N ₂ (see FIG. 1).

Next, FIG. 5 shows another embodiment. In this embodiment, the wind turbine 1 has a single blade 12. That is,
The wing 12 is the same as the main wing 4 of the double wing 3 shown in FIG.

FIG. 6 shows a modification of the double wing 3 shown in FIG. 1. In this case, another sub wing 5 is provided on the sub wing 5 of FIG. 1 with a predetermined interval N ₁ and a predetermined shift width N _2. It is arranged.

FIG. 7 shows another embodiment of the double wing 3 in which two sub wings 5 and 5 having different lengths are provided.

Next, specific examples of the wing 12 or the main wing 4 are shown in Table 1 below. Note that i in Table 1 is a numeral (number) indicating each position in FIG. 8 with i = 0 at the blade tip, i = 20 at the axis L of the center of rotation, and equally dividing the interval by 20. It is.

[0060]

[Table 1]

[0061]

Since the present invention is configured as described above,
The following effects are obtained.

According to the wind turbine of the first aspect, the wings 12 are attached so as to have a negative angle β between the airflow W ₂ to the wings 12 and the surface of the wings 12 corresponding to the ninth line segment UV. , A negative pressure due to the negative angle β can be applied to the lift described by Bernoulli's theorem. Therefore, a large torque can be obtained, and the windmill efficiency can be increased.

According to the wind turbine of the second aspect, the lift of the double wings 3 is obtained by applying a negative pressure due to the negative angle β to the lift described by Bernoulli's theorem on the main wings 4. , And an extremely large torque can be obtained, and the windmill efficiency can be further increased.

Further, according to the wind turbine according to the first aspect and the wind turbine according to the second aspect, even if the diameter is smaller than that of the conventional wind turbine, it is possible to obtain the same torque as the conventional one.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an embodiment of a wind turbine according to the present invention.

FIG. 2 is a diagram illustrating a main wing.

FIG. 3 is a front view of the windmill.

FIG. 4 is a perspective view of a double wing.

FIG. 5 is a front view of another embodiment.

FIG. 6 is a cross-sectional view of a modified example.

FIG. 7 is a side view of another embodiment of the double wing.

FIG. 8 is a diagram illustrating a main part.

FIG. 9 is a cross-sectional view of a conventional example.

FIG. 10 is a cross-sectional view of a conventional example.

[Explanation of symbols]

Reference Signs List 3 double wing 4 main wing 5 sub wing 6 wind receiving surface 7a curved surface 7b curved surface 12 wing O 1st midpoint E 2nd midpoint F 3rd midpoint X 1st point X '2nd point H 1st perpendicular I 2nd perpendicular J third perpendicular line K fourth perpendicular Q first intersection O ₁ second intersection S third intersection point O ₂ fourth intersection U contacts V fifth intersection N ₁ a predetermined distance N ₂ predetermined shift width XX 'first line segment OP second segment OQ third line segment OO ₁ fourth line XR fifth line segment QS sixth segment SO ₂ seventh line X ₁ R ₁ eighth line UV ninth line segment OX 10 segment YY 'linear OQ First arc VX Small arc QST Second arc QSU Third arc ρ Predetermined angle 所 定 Predetermined leading edge angle

Claims (2)

(57) [Claims] 1. A first line segment X connecting a first point X and a second point X '.
X 'is drawn, a second line segment OP is drawn at a predetermined angle ρ from the first middle point O of the first line segment XX', and a first perpendicular line H and a second line segment set at the second point X 'are drawn. First intersection Q with OP
, A second perpendicular I is drawn from a second midpoint E of a third segment OQ connecting the first midpoint O and the first midpoint of the second perpendicular I and the first segment XX ′. A straight line YY 'passing through O
When the fourth line segment OO ₁ about the second intersection point O ₁ pulling the first arc OQ whose radius of addition, the first line segment X
A fifth line segment XR is drawn at a predetermined leading edge angle に 対 し て with respect to X ′, and a third intersection S between the fifth line segment XR and the straight line YY ′ is drawn.
, A third perpendicular J is drawn from a third midpoint F of a sixth line segment QS connecting the first intersection Q and the third perpendicular J and the straight line Y.
Pull the second arc QST to the seventh segment SO ₂ and the radius around the fourth intersection point O ₂ of the Y ', further, the parallel to the fifth segment XR together with contact with the second arc QST 8 A line segment X ₁ R ₁ is drawn, and the first point X, and a fifth intersection V between the fourth perpendicular line K set at the first point X and the eighth line segment X ₁ R ₁
And a ninth line segment UV connecting the contact point U between the second arc segment QST and the eighth line segment X ₁ R ₁ and the fifth intersection point V, and the contact point U. A third circular arc QSU continuous with the ninth line segment UV, the first circular arc OQ, a tenth line segment OX connecting the first middle point O and the first point X, and the small circular arc VX; And a plurality of radially provided wings 12 having a cross-sectional shape surrounded by the ninth line segment UV, the third arc segment QSU, the first arc segment OQ, the tenth segment segment OX, and the small arc segment VX. A windmill characterized by the following. 2. A first line segment X connecting a first point X and a second point X '.
X 'is drawn, a second line segment OP is drawn at a predetermined angle ρ from the first middle point O of the first line segment XX', and a first perpendicular line H and a second line segment set at the second point X 'are drawn. First intersection Q with OP
, A second perpendicular I is drawn from a second midpoint E of a third segment OQ connecting the first midpoint O and the first midpoint of the second perpendicular I and the first segment XX ′. A straight line YY 'passing through O
When the fourth line segment OO ₁ about the second intersection point O ₁ pulling the first arc OQ whose radius of addition, the first line segment X
A fifth line segment XR is drawn at a predetermined leading edge angle に 対 し て with respect to X ′, and a third intersection S between the fifth line segment XR and the straight line YY ′ is drawn.
, A third perpendicular J is drawn from a third midpoint F of a sixth line segment QS connecting the first intersection Q and the third perpendicular J and the straight line Y.
Pull the second arc QST to the seventh segment SO ₂ and the radius around the fourth intersection point O ₂ of the Y ', further, the parallel to the fifth segment XR together with contact with the second arc QST 8 A line segment X ₁ R ₁ is drawn, and the first point X, and a fifth intersection V between the fourth perpendicular line K set at the first point X and the eighth line segment X ₁ R ₁
And a ninth line segment UV connecting the contact point U between the second arc segment QST and the eighth line segment X ₁ R ₁ and the fifth intersection point V, and the contact point U. A third circular arc QSU continuous with the ninth line segment UV, the first circular arc OQ, a tenth line segment OX connecting the first middle point O and the first point X, and the small circular arc VX; Wings 4 having a cross-sectional shape surrounded by the ninth line segment UV, the third arc segment QSU, the first arc segment OQ, the tenth segment OX, and the small arc segment VX;
Are arranged substantially in parallel with a predetermined interval N ₁ and a predetermined shift width N _2, and the first arc OQ of the main wings 4.
A double wing 3 having a substantially uniform thin sub-wing 5 having the same curved surface 7a, 7b as the wind receiving surface 6 composed of 10 line segments OX,
A windmill comprising a plurality of radially arranged windmills.