JP2011058483A - Small propeller wind turbine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent small propeller wind turbine efficiently generating electric power even at a low wind speed, having no breakage of the wind turbine even in strong wind with low environmental load. <P>SOLUTION: The propeller wind turbine includes blades having a corrugated profile while cantilever-supporting them by elastic bodies. The blades and the elastic bodies are formed of paper. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a propeller wind turbine, and more particularly to a small propeller wind turbine for small-scale power generation. The small propeller windmill according to the present invention is suitable for small-scale wind power generation with a low environmental load.

  While wind turbines used for wind power generation can acquire power using powerful natural energy, the wind turbines need measures to withstand strong winds and pass winds in the natural environment. It is said that.

  In general, in a propeller windmill with a fixed blade mounting angle of attack (pitch angle), the rotational speed of the windmill generally increases in proportion to the wind speed, so the centrifugal force acting on the blade is Since it increases in proportion to the square of the wind speed, the lift and resistance generated in the blade also increase in proportion to the square of the wind speed. It can be said that the wind pressure acting on the air pressure increases in proportion to the square of the wind speed. For this reason, in a simple propeller wind turbine in which no countermeasure is taken, if the wind speed exceeds a certain value, the wind turbine is destroyed by centrifugal force and wind pressure that increase in proportion to the square of the wind speed. Since this is obvious, various propeller wind turbines that have been known so far have been subjected to various strong wind countermeasures.

  In a relatively large and expensive propeller wind turbine, a countermeasure against strong winds that suppresses an increase in centrifugal force and wind pressure acting on the wind turbine by changing and controlling the pitch angle of the blade according to the wind speed using a mechanical mechanism or the like is provided. Are known. For example, Patent Document 1 discloses an invention in which a pitch mechanism of a plurality of blades provided in a wind turbine is independently changed and controlled by a mechanical mechanism provided in a hub of a propeller wind turbine (see Patent Document 1). .)

  In addition, while it is not possible to incorporate such a complicated pitch angle change control mechanism, it is easy to be affected by wind turbulence because it is installed near the surface of the earth, and a small propeller that requires a countermeasure against wind shear is also required. Conventionally, wind turbines have taken measures against strong winds and wind shear, mainly by increasing the strength of wind turbine blades and blade mounting parts, and mechanical or electromagnetic mechanisms that brake the rotation of wind turbine blades. Measures against strong winds, measures against strong winds that use blade torsional deformation due to the action of centrifugal force to slow down the blades and suppresses the increase in rotation speed, and strong winds that orient the blade rotation surface of the windmill itself parallel to the wind direction Countermeasures are known.

  However, in the case of countermeasures against strong winds accompanying the rigid structure or enlargement of these windmills, it can be said that there are disadvantages that the startability and power generation efficiency of the windmills at low wind speeds are impaired. PROVEN as a small propeller wind turbine designed to generate power efficiently from low wind speeds to strong winds and without causing damage to the wind turbines, without taking measures against strong winds due to rigid construction or large size. A windmill is known. The conventionally known PROVEN wind turbine is characterized in that a wind turbine blade is allowed to have a flap angle by providing a hinge at a blade mounting portion of the wind turbine, so that the wind turbine blade is imparted with a characteristic of flying in the wind. (See Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5, and Patent Document 6.)

JP 2003-56448 A Japanese Patent Publication No. 25-3964 Japanese Patent Publication No. 29-8608 JP-A-4-103883 JP-A-9-79127 Japanese Patent No. 3435540

  In recent years, as fossil fuel depletion problems and environmental destruction problems have become apparent, the importance of wind power generation has increased, and wind power generators capable of generating power even at lower wind speeds and lower environmental impacts. It can be said that a wind power generator capable of generating electricity is desired. Therefore, the present invention can efficiently generate power even at a lower wind speed than a conventionally known small propeller windmill, and the windmill is not destroyed even at a strong wind, and in addition, the environmental load is small. An object is to provide an excellent small propeller windmill.

  The present invention has the following configuration in order to solve the above problems. That is, the small propeller windmill according to the present invention is characterized in that a blade having a corrugated airfoil is cantilever-supported by an elastic body.

  The small propeller windmill according to the present invention is characterized in that the blade having the corrugated airfoil and the elastic body are provided by paper.

  Moreover, the small propeller windmill according to the present invention is characterized in that a weight is provided on the rear end side of the tip of the blade having the corrugated airfoil.

  Further, the small propeller windmill according to the present invention includes a plurality of blades having the corrugated airfoil arranged symmetrically with respect to a rotation center axis of the blade having the corrugated airfoil, and rotation of the blade having the corrugated airfoil. The elastic body is provided so as to be cantilevered by the elastic body provided symmetrically and integrally with the central axis.

  The small propeller wind turbine according to the present invention has a configuration in which a blade having a corrugated airfoil is cantilevered and supported by an elastic body, and based on the aerodynamic characteristics of the blade having the corrugated airfoil, that is, at low wind speed, low rotation, The aerodynamic performance (lift-drag ratio) of the blade in the low Reynolds number region can be greatly improved, and the blade having the corrugated airfoil is cantilevered and supported by an elastic body. Since the blade support hinge and the flap angle control mechanism, which are required in the PROVEN wind turbine, are not required, the wind turbine can be configured to be extremely small and light. Rotational startability can be greatly improved and the power generation efficiency of the wind turbine at low wind speeds can be greatly increased. It can be improved.

  On the other hand, in a strong wind, that is, in a region where the Reynolds number is high, it can be said that the aerodynamic characteristics of the blade having the corrugated wing shape are drastically reduced. The mechanical performance (lift-drag ratio) can be drastically reduced and the elastic body that cantilever-supports the blade having the corrugated airfoil can be greatly elastically deformed. The elastic deformation gives a large flap angle to the blade having the corrugated airfoil, thereby preventing the windmill from being destroyed in a strong wind.

  Moreover, since the small propeller windmill according to the present invention is configured to provide the blade having the corrugated airfoil and the elastic body with paper, the windmill can be configured extremely lightly. In addition to significantly improving the rotational startability and power generation efficiency at low wind speeds, it is possible to realize an excellent small propeller windmill with less environmental load.

  Further, the small propeller windmill according to the present invention has a weight provided on the trailing edge side of the tip of the blade having the corrugated airfoil, so that the rotation of the blade with the flap angle during strong winds causes the centrifugal force acting on the weight to Due to the action of the component component of the windward direction generated, it is possible to lower the tip trailing edge of the blade having the corrugated airfoil to the windward side, twist the blade and increase the angle of attack of the blade. The stall state of the blade having the corrugated airfoil during a strong wind can be freely controlled to prevent the windmill from being damaged.

  Further, the small propeller windmill according to the present invention includes a plurality of blades having the corrugated airfoil arranged symmetrically with respect to a rotation center axis of the blade having the corrugated airfoil, and rotation of the blade having the corrugated airfoil. A bending moment applied to the elastic body that cantilever-supports a plurality of blades having the corrugated airfoil is configured to be cantilevered and supported by the elastic body that is axisymmetric and integrally provided with respect to the central axis. An elastic body that is axisymmetrically and integrally provided with respect to the rotation center axis of the blade having the corrugated airfoil is distributed and supported substantially symmetrically with respect to the rotation center axis of the blade having the corrugated airfoil. Regardless of the difference in shape and aerodynamic performance of each of the blades having a plurality of corrugated airfoils. To achieve substantially axisymmetric elastic deformation with respect to the rotational center axis of the blade with the corrugated airfoil of the elastic member can be realized rotation of less windmill of smooth and loss.

It is explanatory drawing which shows the small propeller windmill by this invention seeing from a side surface. It is explanatory drawing which shows the corrugated airfoil which the blade | wing of the small propeller windmill by this invention has. It is explanatory drawing which shows balance of the force which acts on the braid | blade of the small propeller windmill by this invention. It is an expansion explanatory view which shows the small propeller windmill by this invention seeing from the side. It is explanatory drawing which shows the wind tunnel experiment result of the small propeller windmill by this invention seeing from a side surface. It is explanatory drawing which shows the small propeller windmill by this invention seeing from the leeward side. It is an expansion explanatory view which shows the small propeller windmill by this invention seeing from the side.

  Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is an explanatory view showing a downwind type propeller wind turbine according to the present invention in which the rotation diameter of a blade is 22 cm at the maximum when viewed from the side. The two Kent paper blades 1 having the corrugated airfoil shape shown in FIG. 1 which will be described in detail later are provided by being bonded and fixed to two Kent paper thin plates (elastic bodies 2), respectively. Each of the elastic bodies 2 is fixed to the hub 3 in a state where the elastic bodies 2 are bonded and fixed to the hub 3 made of Kent paper, that is, the blade 1 is cantilevered by the elastic body 2 which is a thin board made of Kent paper. Is provided.

  A hub 3 made of Kent paper shown in FIG. 1 is directly connected and fixed to an input shaft 4a of a generator 4 which is a micro-generator, and the generator 4 is a stabilizer plate made of four separate Kent papers. 5 is connected to and fixed to one end of a horizontal column 6 made of a steel cylindrical rod that is bonded and fixed in the vertical direction and the horizontal direction, respectively. Further, the horizontal column 6 is also formed of a steel cylindrical rod. As a whole, a vertical wind turbine of a downwind type is configured by being rotatably attached to the vertical support column 7 via a rotation support portion 8 configured using a bearing.

  The blade of the small propeller windmill shown in the present embodiment has a corrugated airfoil having the shape shown in FIG. The inventor of the present invention has studied in detail the wing shape of a dragonfly that flies in the low Reynolds number region, and in other regions where the corrugated airfoil has a chord length Reynolds number of less than the order of 10 to the third power. While the aerodynamic performance (lift-drag ratio) surpasses that of the airfoil, the aerodynamic performance (lift-drag ratio) of the corrugated airfoil drastically increases in the region where the chord length Reynolds number exceeds 10 4. It has been found that it has a tendency to decline. This tendency can be said to be common to all corrugated airfoils having an arbitrary uneven shape.

  For this reason, in the small propeller wind turbine shown in the present embodiment, based on the excellent aerodynamic performance (lift-drag ratio) in the low Reynolds number region of the corrugated airfoil, the blade 1, the elastic body shown in FIG. 2 and boss 3 are each made of lightweight Kent paper, and based on the effect of greatly reducing the moment of inertia, the rotational startability and power generation efficiency at low wind speeds are greatly improved compared to conventionally known wind turbines. It can be said that

  On the other hand, in strong winds, it can be said that the aerodynamic performance (lift-drag ratio) of the blade having the corrugated airfoil of the small propeller wind turbine shown in this embodiment is drastically reduced due to an increase in the chord length Reynolds number. FIG. 3A is an explanatory view showing the small propeller wind turbine according to the present embodiment as viewed from above, and lift acting on the blade 1 having a corrugated airfoil provided in the small propeller wind turbine according to the present embodiment. Is smaller than the drag acting on the blade 1 and reduces the rotational force of the windmill, thereby cutting off the proportional relationship between the wind speed and the rotational speed of the windmill during strong winds. Destruction can be prevented.

  Further, during strong winds, the flaps acting on the blade 1 against the decrease in the increase rate of lift acting on the blade 1 having the corrugated airfoil provided in the small propeller wind turbine of the present embodiment shown in FIG. Since the rate of increase of the aerodynamic force becomes abruptly large, lift force acting on the blade 1 is also shown in FIG. 3 (b) which is an explanatory view showing the small propeller wind turbine of the present embodiment as viewed from above. As a result, the increase rate of the centrifugal force acting on the blade 1 that obtains the rotational force is reduced, while the increase rate of the flap aerodynamic force acting on the blade 1 is rapidly increased, and the blade 1 is cantilevered. A large bending moment acts on the elastic body 2 to be supported.

  Here, according to the present invention, as shown in FIG. 4, which is an explanatory view showing the small propeller wind turbine according to the present invention as seen from the side, the elastic body provided by Kent paper in the present embodiment in which the blade 1 is cantilevered. Since the blade 2 can be flexibly elastically deformed and bent on the leeward side, the blade 1 can have a flap angle. Therefore, the wind receiving area of the windmill can be effectively reduced to receive the wind during strong winds. It is possible to prevent the windmill from being destroyed.

  FIG. 5 is an explanatory view showing the result of a wind tunnel experiment in which the small propeller wind turbine according to the present embodiment is rotated in the wind tunnel as seen from the side. In addition, the measurement before the wind tunnel experiment measured that the twist angle of the blade 1 of the small propeller wind turbine according to the present embodiment shown in FIG. 5 used in the wind tunnel experiment was 0 degree and the pitch angle was minus 15 degrees. Has been. In the wind tunnel experiment, in the rotating state at the wind speed of 6 m / s shown in FIG. 5, the small propeller wind turbine according to the present embodiment does not generate a flap angle, and the rotational speed of the wind turbine increases in proportion to the wind speed. confirmed.

  In the wind tunnel experiment, it has been confirmed that the rotational speed of the small propeller wind turbine according to the present embodiment increases in proportion to the wind speed in the region up to the wind speed of 8 m / s. In the region where the wind speed and the rotational speed of the wind turbine are proportional, the small propeller wind turbine according to the present embodiment has the excellent aerodynamics of the blade 1 shown in FIG. 5 having the corrugated airfoil provided in the small propeller wind turbine according to the present embodiment. It can generate large lift very efficiently based on the dynamic performance (lift-drag ratio) and can provide a large rotational force (rotational torque) to the small propeller wind turbine according to the present embodiment very efficiently. Therefore, wind power generation can be suitably performed by converting wind power into electric power more efficiently than a conventional propeller windmill.

  On the other hand, when the wind speed exceeds 8 m / s, the aerodynamic performance (lift-drag ratio) of the corrugated airfoil of the blade 1 provided in the small propeller wind turbine according to the present embodiment shown in FIG. As shown in FIG. 5, the elastic body 2 which is a thin plate made of Kent paper that cantilever-supports the blade 1 can be prevented. By being elastically deformed and bent, a large flap angle begins to be attached at a wind speed of 16 m / s, the flap angle exceeds 45 degrees at a wind speed of 28 m / s, and the flap angle is 40 m / s, which is the maximum experimental wind speed of the wind tunnel. The blade 1 is blown by the wind so as to reach 75 degrees to receive the strong wind, and the small propeller windmill in the present embodiment is not destroyed.

  In addition, in order to more arbitrarily adjust the aerodynamic performance (lift / drag ratio) of the blades provided in the small propeller wind turbine according to the present embodiment, it is an explanatory view showing the small propeller wind turbine according to the present embodiment as viewed from the leeward side. As shown in FIG. 6, a weight 9 for adjusting the angle of attack, which is a paper adhesive tape, is affixed to the trailing edge of the blade 1 with its weight adjusted. By attaching the weight 9 shown in FIG. 6, the tip trailing edge of the blade 1 is caused by the component component of the windward direction force generated by the flap angle of the centrifugal force acting on the weight 9 in the rotation with the flap angle in the strong wind. Is lowered to the windward side, and the blade 1 is twisted and the angle of attack of the blade 1 can be increased at the tip of the blade 1, that is, the blade surface of the blade 1 is twisted to provide twisting. Therefore, it is possible to freely change and control the angle of attack and the stalled state of the blade 1 during a strong wind to prevent the wind turbine from being damaged by this embodiment.

  The small propeller wind turbine according to the present embodiment described above is small and lightweight, so that it can be easily installed anywhere without selecting a location, and it has not been conventionally used for wind power generation. While wind power can be used at wind speeds, power generation can continue without breaking the windmill even in strong winds, and blades and other parts can be made of paper even in high rotation conditions during strong winds. Therefore, it can be said that it is an excellent small propeller windmill that does not pose a danger to the surroundings and can suppress the environmental burden required for manufacturing the windmill to a very small extent.

  Of course, in order to improve the weather resistance against wind and rain, sunlight, etc., the surface of the Kent paper used in this embodiment may be provided by applying a paint having water repellency and ultraviolet blocking performance. Any material such as biodegradable plastic or PET can be used in place of the Kent paper used in the above. In addition, it is of course possible to change the configuration of the small propeller wind turbine according to the present embodiment shown as a down-wind type wind turbine in the present embodiment, and to configure an up-wind type small propeller wind turbine based on the present invention. is there.

  Hereinafter, other examples of the small propeller wind turbine according to the present invention will be described. FIG. 7 is an explanatory view showing another embodiment of the small propeller wind turbine according to the present invention as seen from the side. The configuration of the small propeller wind turbine of this embodiment other than the configuration particularly shown in FIG. 7 and the following description is the same as the configuration of the small propeller wind turbine according to the present invention already shown in the embodiment of the present invention. In the small propeller wind turbine of the present embodiment, the blade 1 having two corrugated airfoils arranged in an axial symmetry (rotational symmetry) with respect to the rotation center axis of the blade 1 having the corrugated airfoil shown in FIG. It is configured to be cantilevered and supported by an elastic body 2 that is axially symmetric (rotationally symmetric) with respect to the rotation center axis of the blade 1 having a corrugated airfoil.

  Further, a through hole having a diameter slightly larger than the diameter of the input shaft 4a of the generator 4 is provided at the rotation center portion of the elastic body 2, and the elastic body 2 is connected to the input shaft of the generator 4 by the through hole. 4a is rotatably supported and assembled. In addition, in the small propeller wind turbine of the present embodiment, a steel stopper 10 having a cylindrical shape shown in FIG. 7 is provided to be fixed integrally with the input shaft 4a of the generator 4, and at the center of rotation. A urethane rubber liner 11 shown in FIG. 7, which has a through hole having a diameter slightly larger than the diameter of the input shaft 4 a of the generator 4, is rotatably supported on the input shaft 4 a of the generator 4. It is assembled and provided.

  With these configurations, when the small propeller wind turbine of this embodiment receives wind power and rotates, the blade 1 having two corrugated airfoils shown in FIG. The rotational center axis of the blade 1 having the corrugated airfoil is caused by a plurality of bending moments that are separately suspended by the elastic body 2 that is axisymmetrically and integrally provided with respect to the rotational center axis of the blade 1 having the corrugated airfoil. Can be distributed substantially axisymmetrically with respect to the blade 1 having two corrugated airfoils, regardless of the difference in blade shape and aerodynamic performance of the blades 1 having the corrugated airfoils. It is possible to realize an ideal windmill rotation with smooth and little loss by realizing substantially axisymmetric elastic deformation with respect to the rotation center axis of the blade 1.

  At this time, in this embodiment, the blades 1 having the two corrugated airfoils provided so as to be freely rotatable by being supported by the input shaft 4a of the generator 4 are simultaneously cut into pieces. A liner 11 provided so that the elastic body 2 to be supported can be freely rotated by being supported by the input shaft 4 a of the generator 4 is fixed integrally with the input shaft 4 a of the generator 4. The input shaft 4a of the generator 4 is rotated via a frictional force generated between the elastic body 2 and the liner 11 and a frictional force generated between the liner 11 and the stopper 10 by rotating while being pressed against the stopper 10 thus formed. In addition, power is generated by transmitting rotational torque generated by the blade 1 having the two corrugated airfoils. Of course, the configuration of the small propeller wind turbine of the present embodiment shown as providing the blade 1 having two corrugated airfoils is configured to provide the blade 1 having two or more corrugated airfoils. Is also possible.

  According to the present invention, a small, light and safe propeller windmill device that can be easily carried and installed can be provided. The small propeller windmill according to the present invention is a new small-scale wind power generation industry, such as wind power generation for charging lithium-ion batteries, etc. that supply power to electronic information devices such as small communication devices or notebook computers with low environmental load. Have the potential to pioneer. For example, a portable cylindrical container provided with a size slightly larger than the diameter of the boss portion of the small propeller wind turbine according to the present invention by utilizing the flexibility of the elastic body that cantilever-supports the blade of the small propeller wind turbine according to the present invention. By inserting the elastic body supporting the blade in a cantilever manner in a bent state and storing the small propeller windmill according to the present invention, the portable cylindrical container can be compactly formed without disassembling the small propeller windmill according to the present invention. Since the small propeller windmill according to the present invention can be easily carried, it can be used for charging mobile phones, notebook computers, etc. at any place.

  In addition, by utilizing the portability of the small propeller windmill according to the present invention, the small propeller windmill according to the present invention is used as a portable emergency wind power generator that can be taken out in an emergency such as a disaster. It is also possible to do this, or alternatively, by utilizing the safety provided by the small propeller windmill according to the present invention made of paper that does not pose a danger to the surroundings, without damaging wild animals etc. It is also possible to use the small propeller windmill according to the present invention as a wind power generator for supplying power to a warning device that generates a sound wave or electromagnetic wave for warning to make a segregation without approaching to the village, The small propeller windmill according to the present invention has the potential to create an unprecedented new industry.

1: Blade 2: Elastic body 3: Hub 4: Generator 4a: Input shaft 5: Stabilizing plate 6: Horizontal strut 7: Vertical strut 8: Rotating support portion 9: Weight 10: Stopper 11: Liner

Claims (4)

  A small propeller wind turbine comprising a blade having a corrugated airfoil and cantilevered by an elastic body.   The small propeller windmill according to claim 1, wherein the blade having the corrugated airfoil and the elastic body are provided by paper.   The small propeller windmill according to any one of claims 1 and 2, further comprising a weight on a trailing edge side of a tip of the blade having the corrugated airfoil.   A plurality of the blades having the corrugated airfoil arranged symmetrically with respect to the rotation center axis of the blade having the corrugated airfoil are axially symmetrical and integrated with the rotation center axis of the blade having the corrugated airfoil. The small propeller windmill according to any one of claims 1 to 3, wherein the small propeller windmill is provided by being cantilevered by the provided elastic body.

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