KR20190126086A - Vertical axis windmills and wind turbines - Google Patents

Abstract

In the vertical axis windmill, the blade 9 is connected to the vertical main shaft via a support. The wing | blade 9 is equipped with the main wing part 10 extended in parallel with a vertical main axis, and the wing tip inclination part 11 extended inclined and bent to the side of a vertical main axis from the both ends of this main wing part 10. As shown in FIG. do. As for the cross-sectional shape of the blade | wing 9, the radial direction outer side and / or the inner surface are radially advancing direction of the blade | wing 9 so that the thickness of radial direction may become thickest at the position near the front end of the rotational direction of the blade | wing 9. It is a shape which gradually expands in the radial direction outward and / or inward from both front-rear and front ends of. The blade tip inclined portion 11 has a shape in which the width of the rotational progression direction of the blade 9 becomes narrow as it goes to the tip end side. As for the stationary point position P of the blade tip inclination part 11, the distance B2 from the rear end of a rotating advancing direction exists in 50%-83% of range with respect to the width B1 of the rotating advancing direction of the blade 9.

Description

Vertical axis windmills and wind turbines

This application claims the priority of Japanese Patent Application No. 2017-050981, Patent Application No. 2017-050999, and Patent Application No. 2017-051024 of March 16, 2017, which are incorporated herein by reference in their entirety. Quote.

This invention relates to the vertical axis wind turbine which has a vertical main axis, and the wind generation device provided with this vertical axis windmill.

Windmills used in the wind turbine generators are roughly divided into horizontal and vertical axes. In the vertical axis type, a rotational force is obtained regardless of the wind direction, and control of the wind direction is unnecessary, so it is often used for a relatively small windmill. In the vertical axis windmill, it is known that the amount of power generated depends on the shape of the blade, and the development of a blade capable of generating good efficiency is in progress. One of them is a blade provided with a blade tip inclined portion at a blade end (for example, Patent Documents 1 to 4). The blade tip inclined portion is a blade tip plate in which the tip side is inclined to be close to the vertical main axis. By providing a blade tip inclination part, generation | occurrence | production of a vortex in a blade tip is suppressed. Thereby, the rotation energy conversion efficiency which converts the energy received from wind into rotation energy can be improved, and also the noise by wind noise can be reduced.

Japanese Unexamined Patent Publication No. 2004-204801 Japanese Unexamined Patent Publication No. 2004-293409 Japanese Unexamined Patent Publication No. 2011-169267 Japanese Unexamined Patent Publication No. 2016-205204

Although the effects of the wing tip bevel described above are known empirically, it is still sufficiently studied how the shape of the entire wing and the shape of the wing tip bevel is related, and how the shape of the wing tip bevel can achieve the optimum effect. There is something that is not. For example, the relationship between the position of the stationary point which is the position of the uppermost point in the axial direction in the blade tip inclination, and the resistance at the time of noise and idle. Was not clear. The resistance at the time of idleness becomes a judgment material of whether rotation is easy to stop under the fluctuation wind of a natural system, and influences generation efficiency. In the vertical axis windmill provided with the wing tip inclination part of the related art, the position of the peak point of a wing tip inclination part is determined empirically, and it was not clear whether it was a suitable position.

An object of the present invention is to provide a vertical axis windmill which can suppress noise and has a low resistance at idle, and is excellent in noise and resistance at idle.

Another object of the present invention is to provide a wind power generation device with low noise and good power generation efficiency under natural winds.

The vertical axis windmill of the present invention, the vertical main shaft is rotatably installed,

A support provided on the vertical spindle,

Wings connected to the vertical spindle through the support and rotating around the axis of the vertical spindle under the wind.

As a vertical axis windmill comprising,

The said wing has a main wing part extended in parallel with the said vertical main axis, and the blade tip inclination part bent and extended inclined toward both sides of the said vertical main axis from the both ends of this main wing part, The said main wing part and the said The cross-sectional shape of the blade over the blade tip inclined portion is at least one of the radially outer side and the inner side such that the thickness in the radial direction becomes thickest at a point closer to the front end than the center in the rotational direction of the blade. It is a shape which expands gradually to the outer side and / or the inner side of radial direction from the front and rear ends of the rotation progress direction of a blade, The said blade tip inclination part is a shape which becomes small gradually the amount of expansion of the surface of a radial direction outer side as it goes to a front end side. Further, the blade tip inclined portion, the width of the direction of rotation of the blade becomes narrower as it goes to the tip side It is a prize,

As for the stationary point position which is the position of the highest end of the said axial direction in the said blade tip inclination part, the distance from the rear end of the said rotating advancing direction is 50%-with respect to the width of the said rotating advancing direction of the said blade. It is in the range of 83%.

The peak point position is more preferably in the range of 60% to 75% of the distance from the rear end of the rotational advancing direction with respect to the width of the rotational advancing direction of the blade.

The blade tip inclined portion is a portion for the purpose of suppressing vane vortices, but the position of the top point of the blade tip inclined portion affects the generation of noise and resistance at idle.

A fluid analysis was performed on the relationship between the position of the peak point of the blade tip inclination and the noise and resistance at idle, and the following results were obtained. That is, with respect to the noise, the larger the ratio of the distance from the rear end of the blade to the peak point position with respect to the width in the direction of rotation of the blade, the less the noise, and the noise is maintained at a high level at around 50% or less. If the ratio exceeds 50%, the noise level is lowered secondarily. Regarding the resistance at idle, the larger the ratio is, the smaller the resistance is. The resistance is somewhat lowered at around 50% or higher, and when the ratio is 50% or lower, the resistance is rapidly large.

Thereby, it turned out that the said ratio exists in the range of 50%-83% totally excellent in noise and resistance at idle. In addition, it was found that the ratio is more preferably in the range of 60% to 75%.

In the present invention, the cross-sectional shape of the blade over the main blade and the blade tip inclined portion is radially outer side so that the thickness in the radial direction becomes thickest at a point closer to the front end than the center of the rotational advancing direction of the blade. Is a shape in which the surface of the blade is gradually expanded outward in the radial direction from both front and rear ends of the rotation progress direction of the blade, and the bending angle of the blade tip inclined portion with respect to the main blade may be within a range of 20 ° to 55 °. . The bending angle of the blade tip inclined portion is more preferably in the range of 40 ° to 50 °.

The blade tip inclined portion is a site for the purpose of suppressing vane vortex, but its bending angle affects the rotational energy conversion efficiency of converting wind energy into rotational energy of the blade. In addition, the bending angle of the blade tip inclined portion also affects the resistance at idle and the degree of noise caused by wind noise. When the resistance at the time of idleness is large, the rotation of the blade is likely to stop when the wind is weak in the variable wind.

The fluid analysis was conducted on the relationship between the bending angle of the blade tip inclination, the rotational energy conversion efficiency, the resistance at idle, and the noise. As a result, the rotational energy conversion efficiency decreases as the bending angle increases. It can be seen that up to some degree. The resistance at idle is the smallest at around 20 °, and the resistance increases even when the angle is larger than the angle, but the change is gentle until around 45 °. The noise gradually decreased from around 0 ° to around 45 °, but did not change much above 45 °, but rather the noise was slightly increased as the bending angle increased.

As a result, it was found that the bending angle of the blade tip inclined portion was in the range of 20 ° to 55 °, and was excellent overall in rotational energy conversion efficiency, resistance at idle, and noise. Moreover, it turned out that the bending angle is more preferable in the range of 40 degrees-50 degrees.

In the present invention, the ratio of the length in the axial direction of the blade tip inclined portion to the length of half of the length in the axial direction of the entire blade may be within a range of 10% to 20%. The ratio of the length in the axial direction of each blade tip inclined portion to the length of half of the length in the axial direction of the entire wing is more preferably in the range of 16% to 18%.

The blade tip inclination is a portion aimed at suppressing vane vortex, but the ratio between the total length of the blade and the length of the blade tip inclination affects the rotational energy conversion efficiency of converting wind energy into rotational energy of the blade. .

The ratio of the length of the blade tip slope to the length of the blade tip slope relative to the length of the half of the length in the axial direction of the entire wing was determined by fluid analysis of the relationship between the total length of the blade and the length of the blade tip slope and the rotational energy conversion efficiency. It was found that the rotational efficiency was the highest at around 17%, and the rotational energy conversion efficiency was lowered even if it became larger or smaller. Moreover, it turned out that the rotation efficiency to some extent is maintained in the said ratio within 10 to 20% of range. From this, the ratio of the length of the blade tip inclined portion to the total length of the blade is preferably within the range of 10% to 20 °, and more preferably within the range of 16% to 18 °.

The wind turbine generator of this invention is equipped with the said vertical shaft windmill and the generator which generate | occur | produces by rotation of the said vertical main shaft of this vertical shaft windmill.

As mentioned above, the vertical axis windmill used for this wind power generator can suppress a noise, and its resistance at idle is small. Therefore, this wind power generator is low in noise and has good power generation efficiency in the direction of fluctuation of natural wind.

Any combination of two or more configurations disclosed in the claims and / or specification and / or drawings is included in the invention. In particular, any combination of two or more of each claim in the claims is included in the present invention.

The present invention will be more clearly understood from the description of the following preferred embodiments with reference to the accompanying drawings. However, embodiments and figures are for illustration and description only, and are not intended to be used to define the scope of the invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in the plurality of drawings denote the same or corresponding parts.
BRIEF DESCRIPTION OF THE DRAWINGS It is a front view of the wind turbine generator provided with the vertical axis windmill which concerns on one Embodiment of this invention.
2 is a plan view of the wind turbine generator.
3A is a front view of the wing of the vertical axis windmill.
3B is a side view of the wing of FIG. 3A.
4A is an enlarged partial view of FIG. 3A.
4B is a partially enlarged view of FIG. 3B.
FIG. 5A is a cross-sectional view taken along the line VA-VA of FIG. 4B. FIG.
5B is a cross-sectional view taken along the line VB-VB of FIG. 4B.
5C is a cross-sectional view taken along line VC-VC of FIG. 4B.
It is a front view which shows a part of each wing sample used for analysis of the bending angle of a blade tip inclination part.
7 is a graph showing the relationship between the bending angle of the blade tip inclined portion and the rotation moment acting on the vertical main axis when the blade rotates by wind.
8 is a graph showing the relationship between the bending angle of the blade tip inclined portion and the rotational moment acting on the vertical main axis at the time of revolving of the blade.
9 is a graph showing the relationship between the bending angle and the noise of the blade tip inclined portion.
FIG. 10 is a diagram showing the maximum sound generation point at the wing tip of each wing sample and the magnitude of the sound. FIG.
It is a front view of each wing sample used for the analysis of the length of a blade tip inclination part with respect to the full length of a wing.
12 is a graph showing the relationship between the length of the blade tip inclined portion with respect to the entire length of the blade and the rotation moment acting on the blade when the vertical axis windmill rotates due to the wind.
It is a top view which showed the cross section of a part of each wing sample used for analysis of the position of the top point of a blade tip inclination part.
14 is a graph showing the relationship between the position of the peak point of the blade tip inclined portion and the noise.
It is a figure which shows the largest acoustic generation place in the blade | wing tip of each wing sample, and the magnitude | size of the sound.
It is a graph which shows the relationship between the position of the top point of a blade tip inclination part, and the rotational moment which acts on a blade | wing at the time of revolution of a vertical axis windmill.

Embodiment of this invention is described with drawing. BRIEF DESCRIPTION OF THE DRAWINGS The front view of the wind turbine generator provided with the vertical axis windmill which concerns on one Embodiment of this invention, and FIG. A pylon 2 is constructed on the foundation 1 stacked on the ground, and a wind power generator 3 is provided on the pylon 2. The wind turbine generator 3 includes a vertical shaft windmill 4, a generator 6 that is generated by rotation of the vertical main shaft 5 of the vertical shaft windmill 4, and other equipment for distribution and control. . The vertical main shaft 5 is an axis extending along the vertical direction, is rotatably supported by a bearing, and has a lower portion connected to the generator 6. The vertical spindle 5, the generator 6, and other equipment are covered by the cover 7.

In the vertical shaft windmill 4, a plurality of blades 9 are attached to the vertical main shaft 5 via the support 8. In the example of the figure, the number of the blade | wings 9 is two, and each blade | wing 9 is provided in the position which differs 180 degree phase centering on the perpendicular | vertical main axis 5. The number of the wings 9 may be three or more. The support body 8 is one horizontal arm 8a fixed horizontally to the upper end of the vertical main shaft 5, and from the vicinity of the central portion of the horizontal arm 8a toward the left and right sides of the figure, respectively. It consists of four inclination arms 8b extending inclined upwardly and obliquely downward. The left wing 9 is coupled to the tip of the left end of the horizontal arm 8a and the two inclined arms 8b on the left side, and the right end of the horizontal arm 8a and the right of the two inclined arms 8b of the horizontal arm 8a. The right wing 9 is coupled to the tip. When the vertical axis windmill 4 receives the wind, the vertical axis windmill 4 rotates around the axis O of the vertical main shaft 5 in the direction of the arrow in FIG. 2.

3A and 3B are front and side views of the blade 9, respectively. The wing | blade 9 is the main blade | wing part 10 extended in parallel with the vertical spindle 5 (refer FIG. 1), ie along an up-down direction, and the vertical spindle 5 from the upper and lower ends of this main blade | wing 10, respectively. It consists of the upper and lower blade tip inclined portion 11 is bent obliquely to the side. The blade tip inclined portion 11 may extend in a straight line or may extend in a curved line. In the case of a curved shape, the curve may be an arc or a combination of a plurality of arcs having different curvatures. The up-and-down wing tip inclination part 11 is formed in the same shape which becomes line symmetry with respect to the center line CL of the longitudinal middle part of the main wing part 10. As shown in FIG.

In addition, in the following description, the axial direction of the vertical main axis 5 is called "up-down direction." Moreover, the outer diameter side of radial direction centering on the axial center O of the vertical main shaft 5 is called "outer side", and the inner diameter side is called "inner side". In addition, when the vertical axis windmill 4 rotates in the arrow direction of FIG. 2, the side which the blade | wing 9 advances is called "front side", and the opposite side is called "rear side". The rotation progress direction R of the blade | wing 9 is determined along the cross-sectional shape of the blade | wing 9 mentioned later.

As shown in FIG. 3A, the cross-sectional shape and cross-sectional dimension of the main blade part 10 are constant over the whole upper and lower parts, and the blade tip inclination part 11 becomes thinner toward the front end side. However, also about the main blade part 10 and the blade tip inclination part 11, thickness will differ according to the position of rotation progress direction R as demonstrated below. The thickness of the blade tip inclination part 11 demonstrated above is with respect to the thickness of the largest thickness part of a rotating advancing direction.

In FIG. 3B, the positions of the maximum thicknesses of the main wing 10 and the wing tip inclination 11 are shown by lines A1 and A2. The line A1 which shows the largest thickness part of the main blade part 10 is a straight line. The line A2 which shows the largest thickness part of the blade tip inclination part 11 is changed by the peak point position P which is a position of the uppermost end of the blade tip inclination part 11 in the up-down direction. The peak point position P is located on the line A2. As shown in the example shown in Fig. 3B, when the peak point position P is located on the extension line of the line A1 indicating the maximum thickness of the main wing 10, the line showing the maximum thickness of the blade tip inclined portion 11 ( A2) becomes a straight line. When the peak point position P deviates from the extension line of the line A1 which shows the maximum thickness part of the main wing part 10, the line A2 which shows the maximum thickness part of the blade tip inclination part 11 is the main wing part 10 It becomes a line bent with respect to the line A1 which shows the largest thickness part of (). In this case, although the line A2 may be a curve or a straight line, in either case, it is preferable that the connection part is connected smoothly to the front end of the line A1, and the base end of the line A2.

As shown in FIG. 4B, which is a partially enlarged view of FIG. 3B, in the main wing portion 10, the front edge 13F and the rear edge 13R are each formed in a straight line, and the width of the rotation progressing direction R is shown. B1 is constant. The front edge 14F and the rear edge 14R of the wing tip inclined portion 11 are formed in curves that are smoothly connected to the front and rear edges 13F and 13R of the main wing 10, respectively. The width of the rotation progressing direction R gradually decreases gradually as it goes to the tip end side. The edges 14F and 14R before and after the blade tip inclined portion 11 are smoothly connected to each other, and the connecting portion becomes the peak point position P. FIG. The curve which forms the edge 14F, 14R before and behind the blade tip inclination part 11 consists of a circular arc and an elliptical arc, for example. The curve forming the edges 14F and 14R may be a single curve or a plurality of curves may be combined. In addition, the edge 14F, 14R before and behind may be comprised combining the straight line and the curve.

As shown in FIG. 4A, which is a partially enlarged view of FIG. 3A, the wing tip inclined portion 11 includes a bent portion 11a and an event portion 11a which are continued at both upper and lower ends of the main wing portion 10. ) And an inclined portion 11b extending obliquely. The front edge 13F of the main wing 10 is straight in front view. The front edge 14F of the blade tip inclined portion 11 is an arc shape that is smoothly connected to the front edge 13F of the main blade portion 10 in the vent portion 11a in this example. The inclined portion 11b is straight. The edges 13R, 14R on the rear side of the main blade 10 and the blade tip inclined portion 11 overlap with the front edges 13F, 14F at the same position.

The outer side surface 15 of the main wing part 10 and the outer side surface 16a of the vent part 11a of the blade tip inclination part 11 are smoothly connected, and the vent part 11a of the wing tip inclination part 11 is connected. The outer side surface 16a of) and the outer side surface 17 of the inclination part 11b are connected smoothly. The outer side surface 16a of the vent part 11a, the outer side surface 16b of the inclination part 11b, and the outer side surface 16 of the blade tip inclination part 11 are comprised. The outer outlines of the main blade 10 and the blade tip inclined portion 11 in FIGS. 3A and 4A correspond to the lines A1 and A2 in FIGS. 3B and 4B, and the main blade 10 ) And the maximum thickness of the blade tip bevel 11. When viewed from the front shown in FIG. 4A, the outer contour line of the outer side of the main wing portion 10 is straight, and the outer contour line of the outer side of the wing tip inclined portion 11 is an arc shape and an inclined portion in the vent portion 11a. In 11b, it is a curve or straight line connected smoothly to the said arc.

In addition, the inner side surface 17 of the main wing portion 10 and the inner side surface 18a of the vent portion 11a of the blade tip inclined portion 11 are smoothly connected to each other so that the bent portion of the blade tip inclined portion 11 is smooth. The inner side surface 18a of 11a and the inner side surface 18b of the inclination part 11b are connected smoothly. In this example, the inner surface 18b of the inclined portion 11b of the blade tip inclined portion 11 is planar except for the tip portion, and the tip portion is curved. The inner side surface 18a of the vent part 11a, the inner side surface 18b of the inclination part 11b, and the inner side surface 18 of the blade tip inclination part 11 are comprised.

5A, 5B, and 5C are sectional views taken along the line VA-VA, VB-VB, and VC-VC of FIG. 4B, respectively. In each of these sectional views, although the main wing part 10 and the blade tip inclination part 11 are shown by the solid, it is actually comprised by various materials for weight reduction. For example, it may be formed hollow by fiber reinforced resin or the like, or may be formed of a lightweight material such as foam or aluminum.

As shown to FIG. 5A, 5B, 5C, the main wing part 10 and the blade tip inclination part 11 are outer side surfaces so that the thickness of a radial direction may become thickest at the point closer to the front end than the center of rotation progress direction R. As shown to FIG. (15, 16) [16a, 16b] and the inner side surfaces 17, 18 and [18a, 18b], with respect to the wing chord length 19, are gradually separated from the front and rear ends from both ends in the radial direction. It is a shape expanding inward. The blade string length 19 indicates a straight line passing through the front end QF and the rear end QR of the wing 9. In other words, the outer side surfaces 15 and 16 expand outward with respect to the wing string length 19, and the inner side surfaces 17 and 18 expand inward with respect to the wing string length 19. Only one of the outer side surfaces 15 and 16 and the inner side surfaces 17 and 18 may have a shape inflated with respect to the wing string length 19.

In the case of the example of FIGS. 5A to 5C, the inner surfaces 17, 18 (18a, 18b) of the main wing 10 and the wing tip inclination 11 are curved in the vicinity of the front end QF inwardly, Although it is linear from the end of this curved part to the back end QR, the shape may expand in the radial direction inward from the front end to the back end, and the center part of the radial direction may be concave. And the rotational trace C of the blade | wing 9 is a trace | route which the front-end QF and the rear-end QR of the blade | wing 9 pass.

As shown in FIG. 5A, the front side of the outer surface 15 and the inner surface 17 of the main wing 10 are connected to each other by a smooth curved surface, and the main wing 10 on this curved surface. ) Is the shear QF. In addition, the rear end sides of the outer side surface 15 and the inner side surface 17 cross each other at an acute angle, and the intersection portion becomes the rear end QR of the main wing portion 10. Similarly, as shown in Figs. 5B and 5C, the front ends of the outer surfaces 16 [16a, 16b] and the inner surfaces 18 [18a, 18b) of the blade tip inclined portion 11 are connected to each other in a smooth curved surface. The front end QF of the blade tip inclination part 11 is located on this curved surface. Moreover, the rear end side of the outer side surface 16 and the inner side surface 18 mutually cross each other at an acute angle, and this intersection part becomes the rear end QR of the blade tip inclination part 11.

The cross-sectional shape of the tip of the main blade 10 and the cross-sectional shape of the base of the blade tip inclined portion 11 are the same. The cross-sectional shape of each part of the inclination direction in the blade tip inclination part 11 may be a similar type whose only a dimension changes according to the position of an inclination direction, or may be a non-like type which changes not only a dimension but a shape. In this embodiment, since the position of the largest thickness part of the main blade part 10 and the blade tip inclination part 11 is in the same position of rotation progress direction R, the cross section of each part of the inclination direction in the blade tip inclination part 11 is carried out. Although the shapes become substantially similar to each other, the blade tip inclined portion 11 when the position of the maximum thickness portion of the blade tip inclined portion 11 is shifted in the rotation progressing direction R with respect to the position of the maximum thickness portion of the main blade portion 10. The cross-sectional shapes of the respective portions in the inclined direction in Fig. 1) do not become similar to each other.

The operation, effect, and specific configuration of the vertical axis windmill 4 of this configuration will be described. The outer side surfaces 15, 16a, 16b and / or the inner side surface 17, so that the cross-sectional shape of the blade | wing 9 becomes thickest at the point near the front end of the rotation progress direction R of the blade | wing 9 in thickness. 18a, 18b is the shape which expands gradually to the outer side and / or the inner side of radial direction from the front and rear ends of the rotation progress direction R of the blade | wing 9 gradually. Therefore, when the wing 9 is subjected to the wind, the lift force is generated in the wing 9, and by this lift force, the vertical axis windmill 4 progresses the rotation shown in FIG. 2 around the axis center O of the vertical main axis 5. Rotate in direction R

When the blade tip inclined portions 11 are provided at both ends of the blade 9, the pressure difference between the inner surfaces 17, 18 and the outer surfaces 15, 16 of the blade 9 becomes small, and the air current is rolled up ( Since entrainment is suppressed, vortex is not easily generated near the blade tip, and noise is suppressed.

Since the cross-sectional shape of the blade | wing 9 was made so that the thickness of radial direction might become thickest at the point near the front end of rotation progress direction R, a strong lifting force generate | occur | produces in the front of rotation progress direction R, and a wing | blade on rotation trajectory C is shown. Even if the pitch angle at which the front end QF and the rear end QR are arranged (0) is 0 °, the blade 9 can rotate. Since the pitch angle is 0 °, the resistance at the time of rotation, in particular, the resistance at idle, becomes small, and the rotation of the vertical axis windmill 4 does not stop.

Moreover, since the width | variety of the rotation progress direction R of the blade | wing 9 becomes narrow as it goes to the front end side, the blade tip inclination part 11 air | atmosphere around the blade | tip edge when the blade | wing 9 is rotating is progressing. Flows smoothly, and noise is suppressed.

The vertical axis windmill 4 of this embodiment further has a detailed shape of the blade tip inclined portion 11 in order to improve rotational energy conversion efficiency, reduce resistance at idle, and suppress noise. have.

[Bending Angle of Wing Tip Tip]

Bending angle (theta) (FIG. 3A) of the up-and-down wing tip inclination part 11 with respect to the main blade part 10 exists in the range of 20 degrees-55 degrees, More preferably, it exists in the range of 40 degrees-50 degrees. Here, the bending angle θ is an angle formed by the center in the radial direction (center of the cross section) of the main wing portion 10 and the center in the radial direction (center of the cross section) of the blade tip inclined portion 11. And the edges 13F and 13R before and after the main blade 10 and the edges 14F and 14R before and after the inclined portion 11b of the blade tip inclined portion 11 coincide with each other. Said preferable bending angle (theta) was obtained by the following fluid analysis.

As the trial samples, five wing samples shown in Fig. 6 were assumed and analyzed. The blade 9A shown in (A) consists only of the main blade part 10, and does not have a blade tip inclination part. In the blades 9B, 9C, 9D, and 9E shown in (B), (C), (D), and (E), the bending angles θ of the blade tip inclined portion 11 are 0 °, 20 °, and 45, respectively. °, 60 °. The entire length of the blade 9A and the entire length of the blade 9B are the same. The wings 9B, 9C, 9D, and 9E have the same length of the main wing portions 10, and the lengths of the wing tip inclination portions 11 are also the same. The sizes of the wings 9B, 9C, 9D, and 9E were about 2800 mm in total length.

(1) Relationship between bending angle of blade tip slope and rotational energy conversion efficiency

For each of the blades 9B, 9C, 9D, and 9E having the blade tip inclined portion 11, the rotation moment acting on the vertical spindle 5 when the blade 9 rotates due to wind blowing in a predetermined direction is calculated. It was. The rotation speed of the blade | wing 9 is changed into four methods, and it calculates and the analysis result of the rotation speed from which the result of the best efficiency was obtained is shown in FIG. From this analysis result, the rotational energy conversion efficiency decreases as the bending angle θ becomes larger, but the rotational energy conversion efficiency remains high until the bending angle θ is around 50 °, and when the bending angle θ exceeds 50 °, the reduction rate of the rotational energy conversion efficiency increases. Could know.

(2) Relationship between bending angle of blade tip slope and resistance at idle

The blade 9 was rotated in a windless environment, and the rotation moment acting on the vertical spindle 5 at this time was calculated. As a result, it can be seen that resistance at idle, that is, rotation of the blade 9 when the wind is weakened does not stop easily. The rotation speed of the blade | wing 9 was made into the rotation speed of the most efficient efficiency obtained by the said analysis of "the relationship between the bending angle of a blade tip inclination part, and rotation energy conversion efficiency." The analysis result is shown in FIG. From the analysis results, it was found that the resistance at idle is the smallest at the bending angle θ around 20 °, and the resistance at idle becomes larger even if the bending angle θ is larger or smaller than this. Moreover, it turned out that the ratio which becomes large when the bending angle | corner (theta) turns to 45 degrees becomes large at idle. For reference, the rotation moment was calculated under the same conditions for the blade 9A having no wing tip bevel, but compared with the blades 9B, 9C, 9D, and 9E having the blade tip bevel 11, 9A shows that the resistance at idle is extremely large.

(3) Relationship between bending angle and blade noise

The blade 9 was rotated in a windless environment, and the sound at the blade tip was calculated. The rotation speed of the blade | wing 9 was made into the rotation speed of the most efficient efficiency obtained by the said analysis of "the relationship between the bending angle of a blade tip inclination part, and rotation energy conversion efficiency." The analysis result is shown in FIG. Further, wings 9A, 9C, 9D, and 9E in which the bending angles θ of the wing 9A and the wing tip inclination portion 11 that do not have the wing tip inclinations are 0 °, 20 °, 45 °, and 60 °, respectively 10 shows the maximum sound generation point at the tip of the blade and the magnitude of the sound. From these analysis results, the noise gradually decreases until the bending angle θ is around 0 ° to 45 °, but when it exceeds 45 °, the noise decreases with each other, and when the bending angle θ is higher than the bending angle θ, the noise tends to increase. I could see that.

From the analysis results of (1) to (3), it is preferable that the bending angle θ is less than 55 ° with respect to the rotational energy conversion efficiency, and the blade tip inclined portion 11 should be provided with respect to the resistance at idle, and with respect to the noise. It is preferable that bending angle (theta) is 20 degrees or more. When these are judged compositely, it is preferable that the bending angle (theta) of the blade tip inclination part 11 with respect to the main blade part 10 exists in the range of 20 degrees-55 degrees, More preferably, it is 40 degrees-50 degrees. In this way, by setting the bend angle θ of the blade tip inclined portion 11, the vertical axis windmill 4 can be obtained that can satisfy the rotational energy conversion efficiency, the resistance at idle, and the noise.

[Length of wing tip inclination with respect to half the length of the wings]

The ratio of the length L2 (FIG. 3A) of the up-down direction of the blade tip inclination part 11 with respect to the half length L1 (FIG. 3A) of the whole length of the up-down direction of the whole wing 9 is in the range of 10 to 20%. More preferably, it exists in the range of 16%-18%. Here, the length L2 of the up-down direction of the blade tip inclination part 11 is the up-down direction from the base end of the vent part 11a of the blade tip inclination part 11 to the top point position P of the blade tip inclination part 11. Indicates length. Said preferable ratio was obtained by the following fluid analysis.

The three wing samples shown in FIG. 11 were assumed as a construct and analyzed. The wing 9F shown in (A) has 11.4% of (L2 / L1), the wing 9G shown in (B) has 17.0% of (L2 / L1), and the wing 9H shown in (C) is (L2 / L1) is 26.8%. Each blade | wing 9F, 9G, and 9H had the same total length (for example, L1 is about 1400 mm), and the bending angle | corner (theta) of the blade tip inclination part 11 was 45 degrees in all.

For each of the blades 9F, 9G, and 9H, the rotation moments acting on the vertical spindle 5 when the blades 9 were rotated by the wind were calculated. The rotation speed of the blade | wing 9 is changed by four methods, and calculation is performed, and the analysis result of the rotation speed from which the result of the best efficiency was obtained is shown in FIG. From this analysis result, it turns out that rotation energy conversion efficiency is the highest when (L2 / L1) is around 17%, and even if it becomes larger than this, rotation energy conversion efficiency will fall. Moreover, it turned out that rotation energy conversion efficiency to some extent is maintained within (L2 / L1) in the range of 10%-20%. From these, the said preferable ratio of the length of the blade | wing 9 and the length of the blade tip inclination part 11 is guide | induced.

[Top position of wing tip slope]

The peak point position P (FIG. 3B) of the blade tip inclination part 11 of the distance B2 from the rear end of the rotation progress direction R of the blade 9 with respect to the width B1 of the rotation progress direction R of the blade 9 is shown. The ratio is in the range of 50% to 83%, more preferably in the range of 60% to 75%. The peak point position P of this preferable blade tip inclination part 11 was obtained by the following fluid analysis.

Four wing samples shown in FIG. 13 were assumed as a construction body, and the analysis was performed. The wing 9I shown in (A) has 83% of (B2 / B1), the wing 9J shown in (B) has 75% of (B2 / B1), and the wing 9K shown in (C) is (B2 / B1) is 53%, and the wing | blade 9L shown to (D) has 33% of (B2 / B1). The width B1 in the advancing direction of each blade 9I, 9J, 9K, and 9L is the same, and the thickness is also the same.

(1) Relation between peak point position and noise of vane tip

The blade 9 was rotated in a windless environment, and the sound at the blade tip was calculated. The analysis result is shown in FIG. In addition, about each wing | blade 9I, 9J, 9K, and 9L, the largest sound generation | occurrence | production point and the magnitude | size of the sound in a blade | wing tip are respectively shown in FIG. From this analysis result, as a whole (B2 / B1) is large, ie, the more the peak point position P of the blade tip inclination part 11 is located in the front side of the rotation progress direction R, the less noise, and (B2 / B1) is 50 It was found that the noise level was maintained at a high level below about%, and when (B2 / B1) exceeded about 50%, the noise level was lowered secondarily.

(2) Relation between peak point position of wing tip inclination and resistance at idle

The blade 9 was rotated in a windless environment, and the rotation moment acting on the vertical spindle 5 at this time was calculated. As a result, the resistance during idle, that is, rotation of the blade 9 when the wind weakens in the variable wind does not easily stop. The analysis result is shown in FIG. From this analysis result, it turned out that resistance as a whole becomes smaller, so that (B2 / B1) is large as a whole, ie, the stationary point position P of the blade tip inclination part 11 is located in the front side of the rotation progress direction R. Moreover, when (B2 / B1) was 50% or more, the resistance at idle is suppressed to some extent, and when it became 50% or less, it turned out that the resistance at idle is large large.

From the analysis results of (1) and (2), it is preferable that (B2 / B1) is 50% or more with respect to the noise, and (B2 / B1) is preferably 50% or more with respect to the resistance at idle. . However, if the peak point position P of the blade tip inclination part 11 is too front side, the surface of the front end of the blade tip inclination part 11 will become large, and air resistance will become large. As a result of judging these in combination, the B2 / B1 value is preferably in the range of 50% to 83%, more preferably in the range of 60% to 75%. In this way, by setting the peak point position P of the blade tip inclined portion, the vertical axis windmill 4 that can satisfy the noise and the resistance at the time of idle can be obtained.

As described above, this vertical axis windmill 4 has a small resistance at idle, and can suppress noise. Therefore, the wind power generator 3 using this vertical axis windmill 4 has good power generation efficiency and low noise.

As mentioned above, although the form for implementing this invention was demonstrated based on the Example, embodiment disclosed here is an illustration and restrictive at no points. The scope of the invention is indicated by the claims rather than the foregoing description, and is intended to include any modifications within the scope and meaning equivalent to the claims.

Next, in the above-mentioned vertical axis windmill, the vertical axis windmill which concerns on the application aspect which is not contained in the scope of the present invention is demonstrated, without limiting the position of the top point in a blade tip inclination part. This application aspect includes the following aspects 1 to 6. The vertical axis windmill according to this application mode can also obtain a vertical axis windmill that is excellent in rotational energy conversion efficiency and / or has low resistance at idle and can suppress noise.

[Sun 1]

A vertical shaft windmill having a vertical main shaft rotatably installed, a support provided on the vertical main shaft, and a wing connected to the vertical main shaft through the support and being rotated around an axis of the vertical main shaft by wind.

The wing has a main wing portion extending in parallel with the vertical main axis, and a wing tip inclination portion bent and extended obliquely from both ends of the main wing portion to the side of the vertical main axis, wherein the main wing portion and the wing tip inclination portion The transverse cross-sectional shape of the blade is gradually diameterd from both front and rear ends of the blade radially forward direction so that the thickness in the radial direction becomes thickest at a point closer to the front end than the center of the blade rotational direction. It is a shape which expands to the outer side of a direction, The said blade tip inclination part is a shape which becomes small gradually the amount of expansion of the surface of a radial direction outer side as it goes to a front end side,

A vertical axis windmill having a bending angle of the blade tip inclined portion with respect to the main blade portion in the range of 20 ° to 55 °.

[Sun 2]

The vertical axis windmill of the aspect 1, WHEREIN: The vertical axis windmill whose bending angle of the said blade tip inclination part exists in the range of 40 degrees-50 degrees.

[Sun 3]

A vertical shaft windmill having a vertical main shaft rotatably installed, a support provided on the vertical main shaft, and a wing connected to the vertical main shaft through the support and being rotated around an axis of the vertical main shaft by wind.

The wing has a main wing portion extending in parallel with the vertical main axis, and a wing tip inclination portion bent and extended obliquely from both ends of the main wing portion to the side of the vertical main axis, wherein the main wing portion and the wing tip inclination portion The cross-sectional shape of the blade is at least one of the radially outer side and the inner side of the blade in front and rear of the blade moving direction so that the thickness in the radial direction becomes thickest at a point closer to the front end than the center of the blade rotating direction. It is a shape which expands in radial direction outwardly and / or inward gradually from both ends, The said blade tip inclination part is a shape in which the expansion amount of the surface of a radial direction outer side becomes gradually small as it goes to a front end side, The said blade tip inclination part The width of the blade rotation progressing direction narrows as it goes to the tip side,

A vertical axis windmill in which the ratio of the length in the axial direction of the blade tip inclined portion to the length of half of the length in the axial direction of the entire wing is in the range of 10% to 20%.

[Sun 4]

The vertical axis windmill according to aspect 3, wherein the ratio of the length in the axial direction of each of the blade tip inclined portions to the length of half of the length in the axial direction of the entire wing is in the range of 16% to 18%.

[Sun 5]

The vertical axis windmill according to the sun 3 or sun 4, wherein the bending angle of the blade tip inclined portion with respect to the main wing is in the range of 20 ° to 55 °.

[Sun 6]

The wind power generator provided with the vertical axis windmill in any one of the suns 1-6, and a generator which generate | occur | produces by rotation of the said vertical main shaft of this vertical axis windmill.

3: wind power generator
4: vertical axis windmill
5: vertical spindle
6: generator
8: support
9: wing
10: main wing
11: wing tip bevel
15: outer side of main wing
16a, 16b: outer surface of the wing tip bevel
B1: width in the direction of rotation of the blade
B2: Distance from the rear end of the blade rotation direction to the peak position
O: center
P: normal position
R: direction of rotation progress

Claims (7)

A vertical main shaft rotatably installed;
A support body installed on the vertical spindle; And
A wing connected to the vertical spindle through the support and rotating around the axis of the vertical spindle under wind;
A vertical axis wind turbine comprising:
The wing includes a main wing extending in parallel with the vertical main axis, and a blade end inclined portion bent inclined from both ends of the main wing to the side of the vertical main axis. The cross-sectional shape of the said wing | blade over a main wing part and the said blade tip inclination part is a radial outer side and an inner side so that thickness may become thickest in the position near the front end rather than the center of the rotational direction of the said blade | wing. At least one surface is a shape which gradually expands from the front and rear ends of the rotation progress direction of the blade to the outer and / or the inner side in the radial direction, and the blade tip inclined portion gradually expands the radially outer surface as it goes toward the tip side. The blade tip inclined portion becomes smaller in shape, and as the blade tip inclined portion moves toward the tip side, the width of the blade advancing direction is It is a narrowing shape,
As for the stationary point position which is the position of the uppermost end of the said axial direction in the said blade tip inclination part, the distance from the rear end of the said rotating advancing direction is the said rotating advancing direction of the said blade. In the range of 50% to 83% by
Vertical axis windmill. The method of claim 1,
The said peak point position is a vertical axis windmill whose distance from the rear end of the said rotating advancing direction is in the range of 60%-75% with respect to the width of the said rotating advancing direction of the said blade. The method according to claim 1 or 2,
The cross-sectional shape of the said wing | blade over the said main wing part and the said blade tip inclination part is radially outer side surface so that the thickness of a radial direction may become thickest at the point near a front end rather than the center of the rotation progress direction of the said wing | blade. It is a shape gradually expanding outward in the radial direction from both front and rear ends of the rotation progress direction of
The bending angle of the said blade tip inclination part with respect to the said main wing part is a vertical axis windmill in the range of 20 degrees-55 degrees. The method of claim 3,
The bending angle of the blade tip inclined portion is in the range of 40 ° to 50 °, the vertical axis windmill. The method according to any one of claims 1 to 4,
The ratio of the length of the said axial direction of the said blade tip inclination part with respect to the half length of the said axial direction of the said whole wing is in the range of 10%-20%. The method of claim 5,
The ratio of the length of the said axial direction of each blade tip inclination part with respect to the length of the half of the said axial direction of the whole said wing | blade is a vertical axis windmill in the range of 16%-18%. The vertical axis windmill according to any one of claims 1 to 6; And
A generator for generating power by rotation of the vertical main shaft of the vertical axis windmill;
Including, a wind generation device (wind generation device).

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