JP2018119483A - Wings and windmills using them - Google Patents

Abstract

The present invention provides a simple and inexpensive blade and wind turbine that generate a rotational torque by a wind parallel to a rotation axis and a wind perpendicular to the wind. A wing in a wind turbine composed of a plurality of wings having a mounting structure arranged around a rotation axis of a rotating base, wherein the wing has an arc-convex long side 10 and a short side 11 extending from a front edge, and a rear wing. The cross section has a streamline shape in which the thickness intersects at the edge and continuously changes, and the curvature of the neutral line d between the long side and the short side of the blade cross section continuously changes from the blade tip to the blade base and the blade The airfoil reference line perpendicular to the cross section changes continuously or intermittently or has a curved shape with a predetermined radius of curvature, and the sign of the neutral line curve of the airfoil cross-sectional shape is the sign of the radius of curvature of the airfoil reference line. When the neutral line is convex in the direction away from the center is defined as a positive value, the curvature of the neutral line d on the blade tip side is within a positive value range of 0% to 8%. The magnitude of the wing base side curvature is in the range of negative values from 0% to -8%, along the airfoil reference line Aerofoil serial cross-sectional shape is disposed. [Selection] Figure 1

Description

  The present invention relates to a wing and a windmill using the wing, and more particularly to a wing and a windmill that can generate a rotational torque by either a wind parallel to a rotation axis or a wind perpendicular to the rotation axis.

  A large number of cooling towers (cooling towers) for air conditioning are installed on the roof of a high-rise building such as a building, and at the same time as exhaust heat from the air conditioning, fluid kinetic energy associated with forced convection heat exchange by a blower is also released. Such fluid kinetic energy is surplus energy, and if this is recovered by a small wind power generator, the efficiency of the entire system is improved, which is also useful from the viewpoint of environmental considerations.

  Usually, cooling towers are often installed outdoors, and the exhausted airflow is affected by natural wind. Therefore, a vertical axis wind power generator is installed in front of the airflow outlet of the cooling tower and the cooling tower is operated. A wind turbine that rotates with the wind of a blower when the cooling tower is stopped and rotates with natural wind when the cooling tower is stopped has been proposed (Patent Document 1).

  In addition, various wind turbine systems combining vertical axis wind turbines and horizontal axis wind turbines have been proposed. During cooling tower operation, the horizontal axis wind turbine is rotated by the wind of the blower that blows upward from the lower side in the vertical direction. There are known wind turbines in which a vertical axis wind turbine and a horizontal axis wind turbine are rotated in cooperation with natural winds blowing from various horizontal directions when the tower is stopped (Patent Document 2, Patent Document 3, and Patent Document 4). .

  Cost reduction is one of the most important issues in putting a wind turbine into practical use. In particular, cost reduction of blades, which are the main elements of a wind turbine, is important.

  For example, the blade shape is simplified by bending a plate-shaped material with a uniform thickness to configure the blade, and attaching the free end of the blade to the blade base so that it is displaced in the blade rotation direction. A wind turbine has been proposed in which the rotational efficiency is simultaneously increased (Patent Document 5).

  In addition, a technique has been proposed in which the blades are erected by centrifugal force acting on the blades at a high wind speed by using elastic deformation of the blades having a uniform thickness (Patent Document 6). However, in the case of a blade with a uniform thickness in a plate shape, the air flow past the leading edge of the blade tends to peel off, and the airfoil is a flow that is used in an aircraft etc. when importance is placed on improving the performance of the wind turbine. It may be desirable to have a linear shape to suppress delamination.

JP 2007-100583 A JP2013-040610A JP 2014-080983 A JP2015-214982A JP 2013-189970 A JP 2014-141901 A

  However, in the wind turbine described in Patent Document 1, cooling is performed by arranging a vertical axis wind turbine with a rotation axis perpendicular to the exhaust flow before the outlet of the cooling tower from which the exhaust flow is discharged upward from the vertical direction. Since it can be rotated by either the natural wind blowing from the direction perpendicular to the exhaust flow from the tower, it rotates for the natural wind blowing from the direction parallel to the rotation axis of the vertical axis wind turbine. I can't let you.

  Moreover, in the windmill of patent documents 2-4, the fault that there is direction dependence with respect to the natural wind in the windmill of patent document 1 is improved with the structure which combined the vertical axis type windmill and the horizontal axis type windmill. However, since it is necessary to combine two types of windmills, the structure is complicated.

  Further, in the wind turbines described in Patent Documents 5 and 6, a plate having a uniform thickness is bent to form a horizontal axis wind turbine to reduce the cost of the blades. However, since the thickness is uniform, the air flow is separated. In addition to the possibility that high performance cannot be obtained, the wing is likely to be elastically deformed.

  In view of such problems, the present invention uses a wing that is capable of generating a rotational torque with either a wind that is parallel to a rotation axis or a wind that is perpendicular to the rotation axis without causing a high structure and cost. It is an object to provide a windmill.

  Therefore, the blade according to the present invention has a plurality of attachment structures arranged around the rotation axis of the rotation base with respect to the rotation base, preferably a plurality of attachment structures rotationally symmetric around the rotation axis so as to ensure smooth rotation. The blade has a streamlined cross-sectional shape whose thickness changes continuously when the long and short sides of the arc extend from the front edge and intersect at the rear edge. The curvature of the neutral line between the long and short sides of the arc-shaped convex section of the blade cross-section varies continuously from the blade tip to the blade base, and the airfoil reference line perpendicular to the blade cross-section is continuous or intermittent Or a curved shape with a predetermined radius of curvature, and the neutral line d of the wing cross section has a sign of the curvature of the neutral line of the wing cross section in a direction away from the center of the radius of curvature of the airfoil reference line. When the convex shape is defined as a positive value, the blade tip side In the blade section, the neutral line d has a curvature of 0% to 8%, and the blade section neutral line d has a curvature of 0% to -8%. An airfoil having the above cross-sectional shape is disposed along the airfoil reference line, and the airfoil is parallel to the rotation axis and the wind perpendicular to the rotation axis. A rotational torque in the same direction is generated around the rotation axis.

  In addition, the blade according to the present invention has a plurality of attachment structures arranged around the rotation axis of the rotation base, preferably a plurality of rotationally symmetric attachment structures around the rotation axis so as to ensure smooth rotation. The blade has a streamlined cross-sectional shape whose thickness changes continuously when the long and short sides of the arc extend from the front edge and intersect at the rear edge. The sign of the mounting angle in the blade cross section is defined as a positive value in the direction in which the leading edge of the blade cross section is head-down with respect to the direction perpendicular to the airfoil reference line perpendicular to the blade cross section and perpendicular to the rotation axis of the rotating base In this case, the attachment angle of the blade cross section at the blade tip side is within a positive angle range of 0 ° to 15 °, and the attachment angle of the blade cross section at the blade base side is a negative angle range of 0 ° to −45 °. The blade mounting angle is continuously from the blade tip to the blade base. The airfoil reference line changes continuously or intermittently or is bent with a predetermined radius of curvature, and the airfoil having the above cross-sectional shape is arranged along the airfoil reference line Further, the present invention is characterized in that a rotational torque in the same direction is generated around the rotation axis for both the wind parallel to the rotation axis and the wind perpendicular to the rotation axis.

One of the features of the present invention is that the wing is formed by bending it into an arbitrary curve along an airfoil reference line perpendicular to the cross section of the wing.
As a result, it acts as a horizontal axis wind turbine for the exhaust flow from the cooling tower near the blade tip, while acting as a vertical axis wind turbine for the natural wind at the blade base side, and the wind turbine characteristics do not depend on the wind direction of the natural wind Therefore, it can rotate with respect to natural winds from all directions.
As a result, the wind turbine can be configured from blades that can rotate with respect to both the wind parallel to and perpendicular to the rotation axis, and the rotation axis of the wind turbine is provided in the discharge direction of the cooling tower in the mainstream direction of the exhaust flow. By installing them in a consistent manner, it can be rotated not only by the exhaust flow from the cooling tower, but also by natural wind blowing in a direction perpendicular to the exhaust flow. When this rotational torque is applied to power generation, it is highly efficient. Power generation is possible.

The second feature of the present invention is that the functions of a vertical axis wind turbine and a horizontal axis wind turbine can be realized with a single blade.
Thereby, a windmill structure is simple and can also reduce material.

Further, the third feature of the present invention is that the wing cross section has a cross-sectional streamline shape having a curvature of 0% to 8% of a streamline shape used in an aircraft or the like.
As a result, separation of the air flow is less likely to occur compared to a plate-shaped blade section having a uniform thickness, and high wind turbine performance can be expected. Further, if the thickness of the blade is increased, the structural strength can be increased.

Furthermore, the fourth feature of the present invention is that a mounting angle is provided so as to twist the blade section around the airfoil reference line perpendicular to the blade section.
Accordingly, if an appropriate angle of attack is set from the blade base to the blade tip, it is possible to obtain higher rotational energy conversion efficiency. In particular, by setting the mounting angle from 0 ° to 15 ° on the blade tip side and the mounting angle from 0 ° to -45 ° on the blade base side, the exhaust flow in a direction parallel to the rotation axis is achieved. On the other hand, the blade tip portion rotates as a highly efficient horizontal axis windmill, while the blade base portion can act as a drag type vertical axis windmill against natural wind in a direction perpendicular to the rotation axis.
The wind turbine blades described in Patent Documents 5 and 6 are different from the present invention in that the free end of the wind turbine blade is attached so as to be displaced in the blade rotation direction with respect to the root of the blade.

  Here, the airfoil reference line perpendicular to the blade cross section may be configured to be arbitrarily bent in a plane specified by the wind turbine rotation axis and a straight line facing the radial direction perpendicular thereto, and the blade tip may be configured with respect to the blade base. Since it is not necessary to shift in the rotation direction, the design and manufacture may be facilitated, and the wing can be firmly fixed by an easy method.

It is a perspective view for demonstrating the basic wing | blade shape in preferable embodiment of the wing | blade which concerns on this invention. It is a perspective view for demonstrating the said wing | blade shape. It is a perspective view which shows the relationship between the said wing | blade and a rotation base. FIG. 4 is a trihedral view for explaining the structure of FIG. 3. It is a figure for demonstrating the definition of the lift, drag, and angle of attack which generate | occur | produce in a general airfoil. It is a figure which shows an example of the aerodynamic data in an airfoil. Wind A parallel to the rotation axis in the blade cross section of the blade type No. 1 on the blade tip side, the resulting wind force f _A , the rotation direction D of the blade, the relative wind force f _D due to the relative rotation of the blade, the angle of attack α, the mounting angle θ It is a figure which shows the relationship of lift _fCL . Vertical wind B to the axis of rotation of the blade tip side of the blade section of the airfoil No.1, illustrates the relationship between the mounting angle θ and its by drag f _CD. Vertical wind B to the rotation axis in the blade section of the airfoil No.7 of the blade base portion is a diagram showing the relationship of the mounting angle θ and its by drag f _CD. Vertical wind B to the rotation axis in the blade section of the different shapes of the airfoil No.7 of the blade base portion is a diagram showing the relationship of the mounting angle θ and its by drag f _CD. It is a figure which shows preferable embodiment of the windmill comprised by five blades shown by FIG.3 and FIG.4. It is a figure which shows other embodiment of the windmill comprised by five blades shown by FIG.3 and FIG.4. It is a figure which shows the example installed in the perpendicular | vertical upper part of the exhaust-flow outlet of the cooling tower of the windmill comprised by three blades shown by FIG.3 and FIG.4. It is a figure which shows the example installed in the vertical upper part of the exhaust-flow outlet of the cooling tower of the other windmill comprised with 3 blades. It is a figure which shows the windmill characteristic obtained by the wind tunnel experiment of the 5-blade windmill shown in FIG. It is a figure which shows the windmill characteristic obtained by the wind tunnel experiment of the said 5-blade windmill. It is a figure which shows the windmill characteristic obtained by the wind tunnel experiment of the said 5-blade windmill. It is a figure which shows the windmill characteristic obtained by the wind tunnel experiment of the said 5-blade windmill. It is a figure which shows the general form of the windmill which assumed that the number of blades was three and the blade shape was uniform with NACAOO18 of symmetrical blades. It is a figure which shows the windmill characteristic obtained by the wind tunnel experiment of the windmill of 3 blades shown by FIG. It is a figure which shows the windmill characteristic obtained by the wind tunnel experiment of the said 3-blade windmill. It is a figure which shows the windmill characteristic obtained by the wind tunnel experiment of the said 3-blade windmill. It is a figure which shows the windmill characteristic obtained by the wind tunnel experiment of the said 3-blade windmill.

Hereinafter, the present invention will be described in detail based on specific examples shown in the drawings. 1 to 14 (excluding FIG. 10) show a preferred embodiment of a wind turbine according to the present invention. First, an example of how to configure the wing will be described with reference to FIG. A single straight line is assumed as the airfoil reference line 12, the airfoil cross section is perpendicular to the airfoil reference line 12, and the arc-shaped convex long side 10 and the short side 11 extend from the leading edge and intersect at the trailing edge. As a result, seven airfoils No. 1 to No. 7 having a cross-sectional streamline shape whose thickness continuously changes are arranged along the airfoil reference line 12 to form a basic airfoil shape.
The blade type No. 1 at the tip of the blade is NACA6518 whose neutral line d between the arc-shaped convex long side 10 and the short side 11 is curved upward, and the curvature ratio (bending amount f ÷ blade chord length c) is 6%. It is said that the wing type. The bending amount f is defined as the distance between the neutral line d and the chord line 13 (chord length c) at the maximum bend position x _f of the neutral line d of the blade cross section.

Here, in the NACA 4-digit series airfoil, among the four digits, the first number indicates the bending ratio%: f / c, and the second number indicates the chord line at the maximum bending position x _f of the neutral line d. Ratio of chord length c between 13 leading and trailing edges: _xf / c percentage divided by 10. Therefore, the maximum bending position x _f is from the leading edge 50% of the positions of the chord length in the case of NACA6518. The two-digit number consisting of the third and fourth numbers indicates the ratio of the maximum blade thickness t between the arc-shaped convex long side 10 and the short side 11 to the chord length c, that is, the ratio of the thickness ratio: t / c. In the case of NACA6518, the thickness ratio is 18%.

  In the position of No.2, the wing profile of NACA4518 with a curvature ratio of 4%, where the neutral line d of the wing cross section is curved upward, is similarly located in the position of No.3. A curved NACA2518 airfoil with a curvature ratio of 2% is arranged. The airfoil at No. 4 position is the reference symmetrical airfoil NACA0018, and from No. 5 to No. 6 and No. 7, the bending direction is opposite to No. 1 to No. 3. An airfoil is arranged. The wing is formed by smoothly connecting the profile of the wing shape at these seven positions along the direction of the wing shape reference line 12.

  FIG. 2 is an example in which each section of the blade shown in FIG. 1 is given an attachment angle θ with the airfoil reference line 12 as the central axis of torsion. In FIG. 2, at the blade tip position No. 1, the mounting angle θ is 2 ° in the head-down direction with respect to the straight line 16 that is perpendicular to the airfoil reference line 12 and perpendicular to the rotation axis 15 of the rotating base 14. In each cross section from position No. 2 to blade base position No. 7, the mounting angles of θ = + 2 °, + 1 °, 0, −15 °, −30 °, −30 ° It has become. The wing is formed by smoothly connecting the profile of the wing shape with attachment angles θ at these seven positions along the direction of the wing shape reference line 12.

  FIG. 3 shows a state in which the blade shown in FIG. 2 overlaps the surface of the rotary base 14 that can rotate around the rotary shaft 15 with the blade cross section of the blade base position No. 7 in a state where the airfoil reference line 12 is bent. The straight line 16 that is the reference of the mounting angle θ shown in FIG. 2 is coupled in a relationship that is perpendicular to both the direction of the rotation axis 15 of the rotating base 14 and the radial direction of the rotating base 14. At this time, the blade cross section of the airfoil No. 1 at the tip of the blade is positioned farthest from the rotary shaft 15 as compared with the blade cross sections at other positions.

  FIG. 4 shows a three-sided view of one wing attached to the rotating base 14 with the airfoil reference line 12 shown in FIG. 3 bent. In this example, an airfoil reference line 12 in which the blade sections from position No. 1 to position No. 7 are bent with a constant radius of curvature, that is, arranged at equal intervals at a central angle of 15 ° along an arc is shown. The radius of curvature of bending of the airfoil reference line 12 is not constant and may be changed. Further, the number of blade cross sections for specifying the airfoil shape need not be seven, and the number of blade cross sections may be smaller or larger. Further, the intervals of the cross sections for specifying the blade shape do not have to be equal, and may be specified by a plurality of blade cross sections arranged at unequal intervals. Furthermore, although the chord length c is constant in the examples shown in FIGS. 1 to 4, the chord length c may be changed. The airfoil need not be a NACA 4-digit series of wings, and may be another airfoil.

Next, the reason why the blades shown in FIGS. 3 and 4 generate a rotational force for both the wind A parallel to the rotation shaft 15 and the wind B perpendicular to the rotation shaft 15 will be described. FIG. 5 is a diagram for explaining definitions of lift f _CL (lift coefficient CL), drag f CD (drag coefficient CD) and angle of attack α generated in a general airfoil. FIG. 5 shows a state where the chord line 13 connecting the leading edge and the trailing edge of the airfoil is inclined with respect to the relative wind 17 by an angle α. This angle α is the angle of attack, and a drag force f _CD acts on the airfoil in a direction parallel to the relative wind 17, and a lift force f _CL acts in a direction perpendicular to the relative wind 17. The lift force f _CL and the drag force f _CD that are aerodynamic forces vary depending on the angle of attack α, and the angle of attack of the magnitude of these aerodynamic forces depends on the airfoil, the viscosity of the surrounding fluid, and the wind speed of the relative wind 17. Dependency also changes.

  FIG. 6 shows an example of NACA6518 aerodynamic data. Data for Reynolds number Re (= cV / ν: ν is the kinematic viscosity coefficient) based on the chord length c and relative wind velocity V is 360,000. Therefore, both the lift coefficient CL and the drag coefficient CD have asymmetrical aerodynamic characteristics with respect to the vertical axis of the angle of attack α.

When the blades shown in FIGS. 3 and 4 receive the wind A parallel to the rotation shaft 15, the state becomes the same as that of a normal horizontal axis wind turbine mainly at a portion near the blade tip, and a rotational force is generated. FIG. 7 shows an example of the blade section of No. 1 blade at the blade tip. In this figure, it is assumed that wind A parallel to the rotation axis is blowing vertically upward from the lower surface side of the blade, and the blade has already moved leftward (rotation direction D) by the action of lift f _CL . The state is assumed.

The movement direction D of the wing is leftward by attaching an attachment angle θ in the counterclockwise direction so that the wing shape is lowered from the straight line drawn in the horizontal direction in FIG. Now assume a mounting angle of + 2 °), which is more reliable at the start of rotation. Therefore, in a steady rotation state at a constant wind speed, the combined relative when viewed from the wing is synthesized by synthesizing the vertically upward wind A and the relative wind (reverse to D) by the wing movement D. Wind power f _G ,
That is, the angle of attack α is determined, and the lift f _CL acts in a direction perpendicular to the combined relative wind.

In FIG. 7, since it is assumed that the blade mounting angle is + 2 °, the angle of attack α is an angle obtained by subtracting the mounting angle θ from the angle between the direction of the combined relative wind and the horizontal direction, and the angle of attack is 10 ° or less. Small values are expected. In this case, referring to the aerodynamic data in FIG. 6, in the range of the angle of attack α of 5 ° to 10 °, the drag coefficient CD is a very small value close to zero, while the lift coefficient CL is 1 to 1.5. Has a large value of the degree. Therefore, the lift f _CL having a large force component in the rotational direction (leftward in FIG. 7) acts predominantly on the airfoil, and operates as a horizontal axis wind turbine.

Next, consider the case of wind B blowing in a direction perpendicular to the rotation axis. FIG. 8 illustrates the state of the drag f _CD at the No. 1 location at the blade tip. The wings can exist at any position of 360 ° around the rotation axis, but in FIG. 8, the drag force f against a certain wind direction (assuming blowing from the right side to the left side in FIG. 8) B is perpendicular to the rotation axis. _The figure which looked at the case where _CD becomes the maximum and the case where it becomes the minimum from the direction perpendicular | vertical to the rotating shaft of a rotation base is drawn.

Since it is assumed that the blade mounting angle θ is + 2 °, the angle of attack when the drag force f _CD is maximum is α = 178 °, and the drag coefficient in this case is NACA6518, the data of FIG. Thus, CD = 0.08731 and, on the other hand, the angle of attack when the drag force f _CD is minimum is α = −2 °, and the drag coefficient in this case is CD = 0.01342 from the data of FIG. Due to the difference in drag coefficient between the two, even in the vicinity of the tip of the blade, the wind perpendicular to the rotation axis generates a rotational force in the direction of the leading edge of the blade, but the value is small (in the example of FIG. The difference between the value and the minimum value is 0.07389). If the frictional resistance of the rotating shaft or the load on the generator is large, there is a high possibility that it will not rotate.

FIG. 9 shows a blade section of No. 7 corresponding to the blade base, representing a portion close to the blade base. Although the wings can exist at any position of 360 ° around the rotation axis, in FIG. 9, the drag force f against a certain wind direction B perpendicular to the rotation axis (assuming that it blows from the right side to the left side in FIG. 9). Two cases are shown in which the _CD is maximized and minimized when viewed from a direction perpendicular to the rotation axis of the rotating base. Since the blade mounting angle θ is assumed to be −30 °, the angle of attack when the drag force f _CD is maximum is α = 150 °, and the drag coefficient in this case is assumed to be NACA6518 as shown in FIG. From the data, CD = 0.67363. On the other hand, the angle of attack when the drag force f _CD is minimum is α = −30 °, and the drag coefficient in this case is CD = 0.45751 from the data of FIG. Since the difference between the drag coefficients is large (in the example of FIG. 9, the difference between the maximum value and the minimum value of the drag coefficient CD is 0.12792), it can act as a drag type windmill in the vicinity of the blade base.

FIG. 10 shows the blade cross section of No. 7 corresponding to the blade base with respect to the wind B perpendicular to the rotation axis, as in FIG. 9, but the blade shape is different from the case of FIG. The case where the attachment angle θ of the blade root is + 30 ° is assumed. Therefore, in the case of FIG. 10, the angle of attack when the drag force f _CD is the maximum is α = 30 °, and the drag coefficient in this case is CD = 0.62137 from the data of FIG. 6 assuming NACA6518. The angle of attack when the drag force f _CD is minimum is α = −150 °, and the drag coefficient in this case is CD = 0.61749 from the data of FIG. The difference between the drag coefficients of both is CD = 0.00388, which is a small value. As shown in FIG. 10, the rotational torque is generated in the clockwise direction, and the rotational force moves toward the trailing edge of the blade. This occurs in the opposite direction to the rotational force generated at the blade tip shown in FIG. Therefore, it is desirable that the attachment angle θ of the blade base is within a negative value range of 0 ° to −45 °.

  FIG. 11 shows an example of a wind turbine in which five blades shown in FIGS. 3 and 4 are arranged on a rotating base. For both the wind A parallel to the rotation axis and the wind B perpendicular to the rotation axis, the wind turbine generates torque that rotates counterclockwise as viewed from above.

  FIG. 12 shows an example in which a ring-shaped collar 20 is attached to the tip of five blades of the wind turbine shown in FIG. As a result, the wind collecting effect can be expected by the principle of generating a negative pressure in the wake of the collar 20 as in the wind lens windmill.

  FIG. 13 is an example in which the number of blades is three in a wind turbine having blades similar to that in FIG. 11, and this wind turbine is further installed in the vertical upper part of the exhaust flow outlet 22 of the cooling tower 21. The maximum diameter of the wind turbine (rotational diameter of the blade tip) is assumed to be 750 mm. The blades of the windmill are bent in a quarter arc shape, and the radius of curvature is 300 mm. A rotating base 14 having a diameter of 200 mm is provided at the base of the wing, and a windmill body portion 23 having a length of about 200 mm is provided at a lower portion thereof to support the windmill. The windmill body portion 23 includes a support arm 25 and a column 26. Is supported by the cooling tower 21. There is a nose cone portion 24 with a built-in generator at a further vertically lower side of the wind turbine body portion 23. However, the resistance received by the wind turbine from the exhaust flow is reduced, and the flow is prevented from being greatly disturbed. The lower side of the nose cone has a tapered structure with a rounded tip to guide it toward the upper wind turbine blade.

  Due to this wind turbine structure, the wind turbine generates a large rotational force mainly in the vicinity of the blade tip due to the flow of the wind A that is discharged upward from the cooling tower 21 and that is parallel to the wind turbine rotation axis. Although rotating and not shown in the drawing, it is coupled to a generator built in the nose cone 24 by a coaxial power transmission shaft to generate power. Even if the cooling tower 21 is stopped and there is no exhaust flow from the vertically lower side, if the natural wind B blows from any direction perpendicular to the rotation axis, a large drag mainly in the vicinity of the blade base. A difference is generated and the wind turbine can be rotated as a drag type.

  It should be noted that the installation of the windmill at the upper part of the cooling tower 21 has an effect of increasing the flow resistance in the discharge of the exhaust flow. Therefore, the tip portion of the windmill having a large rotation diameter is assumed to have an exhaust flow outlet diameter (700 mm is assumed). 13), the vertical distance from the exhaust flow outlet 22 to the tip of the wind turbine blade is about 1000 mm.

  FIG. 14 shows a drag type wind turbine in the wind turbine body shown in FIG. 13 in order to increase the rotational force of the wind turbine when natural wind perpendicular to the rotation axis blows when the cooling tower is stopped. This is an example in which a crossflow wind turbine 27 is installed. The crossflow wind turbine 27 can be coaxially coupled with a power transmission shaft that couples the wind turbine and the generator, so that the rotational torque of the cross flow wind turbine 27 can be applied to the rotational driving force of the generator. The drag type windmill may be a type other than the crossflow windmill, for example, a Savonius type windmill.

  FIGS. 15 to 18 show that a 1/6 model of the 5-blade wind turbine rotor (assuming a maximum diameter of 750 mm) shown in FIG. 11 is manufactured by a 3D printer, and under a wind speed condition of 5 m / s by a wind tunnel experiment. It is the result of measuring the windmill characteristics. 15 and 16 show the results when the wind A is applied to the windmill from a direction parallel to the rotation axis (horizontal arrangement), and since it functions as a horizontal axis windmill, a wide rotation speed range or a wide tip peripheral speed ratio ( Positive torque and output are obtained in the range of the peripheral speed of the blade tip and the wind speed: λ).

  On the other hand, FIG. 17 and FIG. 18 show the results when the wind B is applied to the windmill from the direction perpendicular to the rotation axis (vertical arrangement), and work as a vertical axis windmill. The ratio λ shows that positive torque and output are generated over a wide range up to about 1.3. This indicates that the windmill can rotate well both in the wind A parallel to the rotation axis and in the wind B perpendicular to the rotation axis, and actually rotates.

  FIG. 19 shows an outline of a wind turbine assuming that the number of blades is three and the blade shape is uniform with NACAOO18 which is a symmetrical blade. The blade tip mounting angle is set to θ = 7 ° at which the maximum output is expected when operating as a horizontal axis wind turbine. Since the mounting angle along the airfoil reference line is uniformly set to 7 °, the mounting angle of the blade base is also θ = 7 ° and the rotation direction is drawn in the reverse arrangement. Similarly, the wind turbine is in a head-up mounting state such that the leading edge of the blade cross section of the blade base is away from the center of rotation.

  20 to 23 show that a 1/6 model of the three-blade wind turbine rotor (assuming a maximum diameter of 750 mm) shown in FIG. 19 is manufactured with a 3D printer, and under a condition of a wind speed of 5 m / s by a wind tunnel experiment. It is the result of measuring the windmill characteristics. 20 and 21 show the results when the wind A is applied to the windmill from the direction parallel to the rotation axis (horizontal arrangement), and since it functions as a horizontal axis windmill, a wide rotation speed range or a wide tip peripheral speed ratio ( Positive torque and output are obtained in the range of the peripheral speed of the blade tip and the wind speed: λ).

  On the other hand, FIG. 22 and FIG. 23 show the results when wind B is applied to the windmill from the direction perpendicular to the rotation axis (vertical arrangement), and the arrangement of the vertical axis windmill is measured in almost all rotation speed states. Torque and output are negative values, which indicates that the wind turbine is not functioning and is only driven by the motor used in the experiment. That is, when the leading edge of the blade cross section of the blade base is raised, that is, when the mounting angle is a positive value, the wind parallel to the rotation axis is perpendicular to the rotation axis even if it rotates as a windmill. It shows that it does not rotate against a strong wind.

DESCRIPTION OF SYMBOLS 10 Arc convex long side 11 Short side 12 Airfoil reference line 13 Blade chord line 14 Rotation base 15 Rotating shaft 20 Collar ring 21 Cooling tower 22 Exhaust flow outlet 27 Cross flow windmill (drag type windmill)

Claims (7)

A blade in a wind turbine comprising a plurality of blades having a mounting structure disposed around a rotation axis (15) of the rotating base (14) with respect to the rotating base (14),
The wing has an arc-convex shape in which the thickness of the wing cross-section is continuously changed by the arc-convex long side (10) and the short side (11) extending from the leading edge and intersecting at the trailing edge. The curvature of the neutral line d between the long side (10) and the short side (11) continuously changes from the blade tip to the blade base, and the airfoil reference line (12) perpendicular to the blade cross section is continuous. A shape that changes periodically or intermittently or has a predetermined radius of curvature,
The sign of the curvature of the neutral line d of the blade cross-sectional shape is defined as a positive value when the neutral line d of the blade cross-section is convex in a direction away from the center (18) of the radius of curvature of the airfoil reference line (12). Then, the magnitude of the curve of the neutral line d on the blade cross section on the blade tip side is within a positive value range of 0% or more and 8% or less, and the magnitude of the curve of the neutral line d on the blade base side is In the negative range of 0% to -8%,
An airfoil having the cross-sectional shape is arranged along the airfoil reference line (12), and for either the wind A parallel to the rotation axis (15) or the wind B perpendicular to the rotation axis (15). However, the wing is characterized in that a rotational torque in the same direction is generated around the rotating shaft (15). A blade in a wind turbine comprising a plurality of blades having a mounting structure disposed around a rotation axis (15) of the rotating base (14) with respect to the rotating base (14),
The blade has a streamlined cross-sectional shape in which the arc-convex long side (10) and the short side (11) extend from the leading edge and intersect at the trailing edge, and the thickness continuously changes. The leading edge of the blade section is head-down with reference to the direction (16) perpendicular to the airfoil reference line (12) perpendicular to the blade section and perpendicular to the rotation axis (15) of the rotating base (14). When the direction is defined as a positive value, the blade cross section mounting angle θ on the blade tip side is within the positive range of 0 ° to 15 °, and the blade cross section mounting angle θ on the blade base side is from 0 ° to − Within the negative angle range of 45 °, the mounting angle θ of the blade cross section continuously changes from the blade tip to the blade base, and the airfoil reference line (12) changes continuously or intermittently. Or a bent shape with a predetermined radius of curvature,
An airfoil having the above-mentioned cross-sectional shape is arranged along the airfoil reference line (12), and the wind A is parallel to the rotation axis (15) and the wind B is perpendicular to the rotation axis (15). A wing characterized in that a rotational torque in the same direction is generated around the rotating shaft (15).   The mounting angle θ on the blade cross section is orthogonal to the airfoil reference line (12) perpendicular to the blade cross section and the direction (16) perpendicular to the rotation axis (15) of the rotating base (14) is used as a reference. When the direction in which the leading edge of the blade cross-section is defined as a positive value is defined as a positive value, the attachment angle θ of the blade cross-section on the blade tip side is within a positive angle range of 0 ° to 15 °, and the blade on the blade base side The blade according to claim 1, wherein the mounting angle θ of the cross section is in a negative angle range of 0 ° to -45 °, and the mounting angle θ of the blade cross section continuously changes from the blade tip to the blade base.   The blade according to any one of claims 1 to 3, wherein the chord length c of the airfoils arranged along the airfoil reference line (12) is constant, or changes continuously or discontinuously.   Wind turbine characterized in that a plurality of blades according to any one of claims 1 to 4 are arranged around a rotating shaft (15) of a rotating base (14).   The wind turbine according to claim 5, further comprising a collar-like ring (20) having a wind speed enhancing function at a tip of the blade. The wind turbine according to claim 5 or 6, wherein a drag type wind turbine (27) having the same rotation axis is combined.

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