WO2013104578A1

WO2013104578A1 - Wind tower

Info

Publication number: WO2013104578A1
Application number: PCT/EP2013/050147
Authority: WO
Inventors: Enrico Bozano
Original assignee: Enrico Bozano
Priority date: 2012-01-12
Filing date: 2013-01-07
Publication date: 2013-07-18
Also published as: ITGE20120002A1

Abstract

Wind tower, comprising a substantially vertical shaft (5) connected to an electric generator (2); said tower comprises a series of wind rotors (9) arranged in a circle and connected to support means (6, 7) integral with said vertical shaft (5), being said rotors (9) rotating with respect to said support means (6, 7) and adapted to put into rotation said support means (6, 7) and said vertical shaft (5) thanks to the wind action that, due to the Bozano effect, determines on the axes (10) of each of said rotors (9) forces (A1 -A6) perpendicular to the direction (V) of the wind and oriented, initially and for low wind speeds, in the opposite direction to the rotation motion (R) of said rotors (9); the direction of the said forces is reversed for higher speeds of the wind, therefore in the same direction of the rotors rotational motion.

Description

TITLE:

WIND TOWER DESCRIPTION

The present invention relates to a wind tower.

As known the wind energy derives from the conversion of the kinetic energy possessed by the wind into mechanical and electrical energy. Among the devices that exploit the wind energy there are the so-called wind towers, which generally comprise blades with horizontal or vertical axis that are actuated by the wind and are integral with a shaft cooperating in known manner with an alternator to produce electricity.

The purpose of the present invention is the construction of a wind tower with a vertical axis that will prove to be extremely efficient, functioning also with winds of weak entity and flowing from any direction.

This objective is achieved by the present invention by way of a wind tower, comprising a substantially vertical shaft connected to an electric generator, characterized by comprising a series of wind rotors arranged in a circle and connected to support means integral with said vertical shaft, said wind rotors rotating with respect to said support means and being adapted to put into rotation said support means and said vertical shaft thanks to the wind action that, in the first place causes the rotation of said rotors with a rotation speed proportional to its intensity, while in the second place, for an effect discovered by the owner of the present application and in the following called "Bozano effect", determines on the axes of each of the rotors in rotation, certain forces perpendicular to the wind direction that, in the initial step, i.e. with wind speeds up to a certain value, are oriented in the opposite direction to the rotation movement of the rotors, while subsequently, therefore for a further increase of the wind speed, the rotation direction is reversed and the thrusts are oriented in the same rotation direction of the rotors.

Basically for said Bozano effect that is applied to the wind rotors, there are different phenomena from those that occur in the known "Magnus" effect that instead considers only cylinders or full rotating geometries. The first most obvious difference is that the rotors, from the resting state, due to the action of the wind begin automatically to spin thus triggering the above forces perpendicular to the wind direction, while the cylinder considered by Magnus, is in the resting state, and remains in said state and no induced forces appear.

Another difference appears in the case of low wind intensity during this step, in fact, the direction of perpendicular forces is in the opposite direction compared to that present with the Magnus effect in the case of a rotating cylinder and with equal wind intensity.

Of great importance is then the phenomenon which manifests itself only with the rotors and not with the cylinders of the Magnus effect, namely that increasing the wind speed increases even automatically the rotation speed of the rotors, then both factors intervene in an automatic manner to increase the perpendicular forces to the wind direction; while in the Magnus cylinders their rotation speed is not dependent on the wind speed but on the motor apparatus, to which it remains constant when the wind increases, unless the speed of the engines that make them turn is varied.

At last, fundamental is the difference in yield for the production of energy between the two systems, i.e. one of the Magnus effect type, composed of rotating cylinders and the other of the Bozano effect type, composed of wind rotors: in the Bozano plant that uses the rotors all the energy produced can be sent to the user, while in the plant that uses the cylinders of Magnus type, a part of the energy produced must be used to spin the cylinders themselves, therefore the greater the number of cylinders that compose the system, the greater the energy that must be used to put them into rotation. In the Bozano plant instead the greater the number of rotors, the greater the amount of energy that the plant of the wind tower can produce, without any waste.

Further characteristics and advantages of the present invention will be better understood in the course of the following description, regarded in an illustrative and non-limiting way and in reference to the accompanying drawings, wherein:

- Fig. 1 shows a sectional view of a wind tower with vertical axis according to the present invention and provided with a series of wind rotors rotating pivoted on the outer circumference of two wheels;

- Fig. 2 shows a plan view of a bottom wheel of the wind tower of Fig. 1 ;

- Fig. 3 shows a front view of the wind tower of Fig. 1 ;

- Fig. 4 shows a sectional view of an alternative embodiment of the present wind tower inside which fans are placed, whose function is to suck the internal air flow and direct it in an upward motion towards the outside through the upper wheel;

- Fig. 5 shows a front view of the present wind tower provided with an external fairing;

- Fig. 6 shows a plan view of the wind tower provided with fairing of Fig. 5;

- Fig. 7 shows a side view of the present wind tower provided with external fairing;

- Fig. 8 shows the wind tower of Fig. 4 provided with external fairing;

- Fig. 9 shows a plan view of the wind tower provided with the particular fairing of Fig. 10, adapted to optimize the flows, and

- Fig. 10 shows the front view of the wind tower provided with the particular fairing of Fig. 9.

With reference to said accompanying drawings and with particular reference to Fig. 1 thereof, number 1 indicates the support structure of a wind tower with vertical axis according to the present invention. Said structure 1 comprises a base 101 secured to the ground and a compartment 201 housing an electric generator 2 positioned on the base 101 . Said generator 2 comprises a shaft 3 connected by way of a joint 4 to a vertical axis 5, crossing a cylindrical upright 301 arranged above said compartment 201 . Said vertical axis 5 is connected with the central hub of a first bottom wheel 6, positioned substantially at the top of the cylindrical upright 301 , and with the central hub of a second upper wheel 7, positioned substantially at the upper end of said axis. Said first wheel 6 is supported on the cylindrical upright 301 by way of a rolling body 8, for example a bearing or the like, which allows it to rotate with respect to the fixed structure 1 . On the periphery of each of the two wheels 6 and 7 are pivoted wind rotors 9. Each of said wheels will be provided with a number of rays, see for example the rays 12 of the lower wheel in Fig. 2. Each of said rotors 9 is centrally traversed by a pin 10 which is fixed to the upper end in the vicinity of the periphery of the upper wheel 7 and to the lower end near the periphery of the lower wheel 6.

In Fig. 2 a plan view of the present wind tower is shown wherein can be better understood the arrangement in circle of the rotors 9, equally spaced one from the other and from the vertical axis 5. The lower wheel 6 comprises a series of rays 12 of number equal to the number of rotors 9.

Each of said rotors 9 is put into rotation, for example in the direction of the arrows R of Fig. 2 by the wind action V. Assuming that the wind tower is hit by a wind having the direction of the arrows V, for the Bozano effect on the rotating wind rotors 9 invested by the wind, perpendicular forces to the wind direction and oriented in the direction T opposite to the rotation of the rotors are created: said forces are symbolized in the figure by the arrows A1 , A2, A3, A4, A5, A6. Said forces A1 -A6 perpendicular to the direction of the wind V are applied on the axes 10 of the rotors 9 which then put into rotation in the direction of the arrow T the whole mobile unit of the wind tower, i.e. the two wheels 6 and 7, the vertical axis 5 and the rotors 9 themselves. As seen, the vertical axis 5 is connected by way of a joint 4 to the shaft of an electric generator 2, therefore, by way of said rotation T an electrical current will be generated by said generator which is substantially proportional to the wind speed and therefore to the rotary motion of the mobile unit of the wind tower, i.e. the axis, the wheels and the rotors.

In Fig. 4 an alternative embodiment of the present wind tower is shown wherein some fans 1 1 are placed inside the same, having the function of aspirating the internal air flow and directing it in an upward motion, outwardly through the upper wheel. In fact, the fans 1 1 are designed to suck the air from the inside of the wind tower in the direction of the arrows D when the unit is in rotation, making it flow out from the upper part of the tower. Said air suction generates a vertical flow that substantially follows the path indicated by the arrows D in Fig.4 flowing out from the upper part of the wind tower. Said upwards vertical air flow in the direction D will then draw the air from the outside in the radial direction. Said draw of air from the outside will facilitate the front air flow due to the wind and will produce a centripetal air flow from the outside towards the inside also to the sides and in the rear part of the tower, thus further contributing to the rotary movement R and creating a further thrust Ap in the side and rear rotors. In essence thanks to the suction of air upwards, generated by the fan 1 1 of the present wind tower, air is drawn from the outside towards the inside of the tower, that in the front part will increase the action of the wind, creating even further impulse to the rotors 9 placed at the sides and at the rear where they would not be exposed to the action of the wind V. The overall force of the wind in the front part and of the suction air flow present at the sides and at the rear will be given by the resultant T, due to the sum of the forces resulting from the Bozano effect A1 - A6 in the front part exposed to the wind plus the sum of all forces Ap due to the radial suction air flow which acts on the remaining ten rotors located at the sides and at the rear part of the wind tower.

The present wind tower provided with rotating rotors 9 can be provided with a suitable swivel fairing 14, see in this regard Figures 5 and 6. Said fairing 14 comprises a cylindrical portion 1 14 which surrounds part of the rotating rotors 9. Said cylindrical part 1 14 has an arc aperture 214 from which the wind is conveyed into the wind tower to interact with the rotating rotors 9. On each side of said opening 214 is positioned an arched shield 314 having the purpose of conveying and better directing the wind inside the tower. Said fairing 14 thus has the function of conveying a greater amount of wind into the tower and optimize the internal vertical and upwardly oriented flow in the direction D. The lower part of the fairing 14 is positioned around the cylindrical upright 314 by way of a support 16 which allows the rotation with respect to the upright, so that it can be oriented from time to time with the opening 214 and the shields 314 facing the direction V of the wind. In this regard, said fairing 14 is provided on the top of a directional rudder 15 able to orient it appropriately and thus exploit the kinetic energy of the wind in an extremely effective way, which is converted into electrical energy through the generator 2.

Said fairing 14 is also provided in the upper part, of a convex cover 214 which has the task of facilitating the escape of the air, thanks to the thrust of the fans, from the top of the wind tower and to direct the wind in the direction of the rotors so as to eliminate as much as possible the thrusts V1 -V2-V3 in Fig. 2 contrary to the motion of the entire unit and due to the direct action of the wind, thus, as seen in Fig. 6 the thrusts V2-V3-V4 being oriented along the rays, have no components that hinder the motion of the system.

Similarly in Figures 9 and 10 is represented one of the various types of fairing that can be made to optimize the flows of air, increasing the thrust of the rotors and canceling, see fig. 9, the wind thrusts V2-V3-V4, to have then the greatest possible yield by the wind towers of the plant for the conversion of wind energy into electrical energy. Ultimately with the fairing of Figures 9 and 10 an attempt is made to eliminate the negative thrusts, i.e. those oriented in the opposite direction to the motion of the entire unit.

The following describes the Bozano effect discovered by the owner of the present application by experimentation. According to the tests carried out, a behavior was found being fundamentally different from that according to the cylinder of the Magnus effect. In the first place it is noted that if the cylinder used for the Magnus effect is stationary, i.e. not in rotation, for any incidence wind speed there will be not any lateral thrust, instead using the rotor of the Bozano effect in place of the cylinder, starting always from stationary rotor, for a certain wind speed the rotor is set in motion and then it triggers independently the phenomenon of the lateral thrust perpendicular to the wind direction.

At this step there is the second difference with respect to the Magnus effect, in fact, for low wind intensity and therefore with the corresponding low rotation of the rotor, a lateral thrust perpendicular to the wind direction but contrary to the direction of rotation of the rotor is triggered, and therefore contrary to the rotation that occurs in the cylinder due to the Magnus effect at equal wind intensities.

With the increase of wind speed there is also a corresponding increase in the rotation speed of the rotor, which does not happen for the Magnus cylinder, in which the increase of the lateral thrust will be due to both components, both the increase in intensity of the wind and the increase of the rotor rotation. Also in the Bozano effect there is a singular phenomenon, which is not found in the Magnus effect for the rotating cylinder, and that is that for a certain wind speed, the direction of the lateral thrust changes, becoming the opposite, i.e. in the same rotation direction of the rotor, remaining then the same even for a further increase in the intensity of the wind.

Claims

1 . A wind tower, comprising a substantially vertical shaft (5) connected to an electric generator (2), characterized in that it comprises a series of wind rotors (9) arranged in a circle and connected to support means (6, 7) integral with said vertical shaft (5), said rotors (9) rotating with respect to said support means (6, 7) and being adapted to put into rotation said support means (6, 7) and said vertical shaft (5) thanks to the action of the wind which, due to the Bozano effect, determines on the axes (10) of each of said rotors (9) forces (A1 -A6) perpendicular to the direction (V) of the wind and oriented, initially and for low wind speeds, in the opposite direction to the rotation motion (R) of said rotors (9), the direction of the said forces being adapted to reverse and direct in the same direction of the rotors rotation motion for higher speed of the wind.

2. The wind tower according to claim 1 , characterized in that said support means comprise a first lower wheel (6) and a second upper wheel (7) centrally connected to said vertical shaft (5), being said rotating rotors (9) arranged in circle near the periphery of said wheels (6, 7).

3. The wind tower according to claim 2, characterized in that each of said rotating rotors (9) is centrally traversed by a pin (10) fixed at its ends to said lower wheel (6) and to said upper wheel (7).

4. The wind tower according to claim 2, characterized in that said vertical shaft (5) comprises a series of fans (1 1 ) adapted to suck air upwards and create inside the tower a vertical air flow, drawing air from the outside in the radial direction.

5. The wind tower according to claim 1 , characterized in that said rotating rotors (9) comprise a suitably dimensioned and oriented blading.

6. The wind tower according to any preceding claims, characterized by comprising an external fairing (14) adapted to convey the wind towards said rotating wind rotors (9).

7. The wind tower according to claim 6, characterized in that said external fairing (14) comprises a cylindrical part (1 14) that surrounds said rotating wind rotors (9) and is provided with an opening (214) through which the wind is conveyed towards said rotating wind rotors (9).

8. The wind tower according to claim 7, characterized in that said fairing (14) comprises at the sides of said opening (214) arched shields (314) adapted to direct and convey the wind inside the tower.

9. The wind tower according to claim 6, characterized in that said fairing (14) is connected to a fixed structure (1 ) of the wind tower by way of a support (16) which allows rotation thereof with respect to said structure (1 ).

10. The wind tower according to claim 6, characterized in that said fairing (14) comprises a directional rudder (15) on the top.