FIELD OF THE INVENTION

The invention concerns a vertical-axis wind turbine which can be used mainly for the generation of electricity for household needs of individual households and for industrial purposes, as component of wind power mills. The vertical-axis wind turbine may also be used for driving various vehicles, but especially those that run on water.

BACKGROUND OF THE INVENTION

Known is a vertical-axis wind turbine which consists of a shaft rotating around longitudinal axis and multiple hard turbine blades mechanically fixed to the shaft. Each one of the multitude of hard turbine blades represents an elongated solid with upper and lower end, where the upper and the lower ends are rotationally shifted one away from the other along the rotation axis so that each turbine blade has with helical shape and the cross section of the elongated solid of each turbine blade has aerodynamic surface. The aerodynamic surface of each turbine blade is with arc-curved shape so that the centre line of the aerodynamic profile of the surface passes along the line of constant curvature with a specified terminal radius of curvature. (RU 2 006 105 624 A).

A disadvantage of the known vertical-axis wind turbines is first and foremost their complicated structure that prevents efficient use of wind energy.

DESCRIPTION OF THE INVENTION

The task of the invention is to create a structure of a vertical-axis wind turbine with simplified and process-oriented design allowing maximum use of the wind power. This task is solved by a vertical-axis wind turbine comprising a shaft rotating around longitudinal axis and multiple hard turbine blades. According to the invention, the turbine blades are combined into one or more turbine units, each consisting either of two identically sized bottom and top tube rings, or of one pair of bottom tube rings concentrically positioned one above the other and one pair of top tube rings concentrically positioned one above the other, so that the inner turbine rings and the outer ones are of the same size. Regardless of the type of turbine unit, the tube rings are fixed perpendicularly to the single shaft by means of distribution washers and load-bearing radial ribs. The length of the load-bearing radial ribs for each turbine unit is different and depends on the diameter of the corresponding turbine unit. The top and the bottom tube rings are positioned in parallel to each other and at a certain distance above each other, so that this distance defines the height of the turbine unit. The height of all turbine units is the same.

In addition to the load-bearing radial ribs, the concentric bottom and top tube rings are connected to each other also with supporting ribs; through the load-bearing radial ribs and supporting ribs the tube rings are divided into equal sectors. The sectors of the top tube rings are located right above those of the bottom tube rings.

When the turbine unit consists of one top and one bottom turbine round, each one of the turbine blades is attached with its one end to a load-bearing radial rib of the top tube ring and with its other end to the subsequent rib of the bottom tube ring.

When the turbine unit consists of one pair of top turbine rounds and one pair of bottom turbine rounds, each one of the turbine blades is attached with its one end to a load-bearing radial rib (or supporting rib) of the top pair of tube rings and with its other end to the subsequent rib of the bottom pair of tube rings.

The vertical-axis wind turbine may be elaborated with different number of turbine units with different number of turbine blades, but for the purposes of this invention the most appropriate are different variations of four turbine units, each with 6, 12, 18 or 24 turbine blades.

In operational position each of the turbine blades has a complex spatial form defined by an inner and an outer contours and by the corresponding ribs of the bottom and top tube rings to which the turbine blade is attached, and the ribs to which turbine blades are attached are located adjacent relative to the vertical axis of the wind turbine.

The outer contour of each turbine blade represents a spatial curve which begins from the corresponding rib of the bottom tube ring. This spatial curve comprises a top and bottom part smoothly overflowing into one another. The bottom part of the spatial curve starts at the outermost end of the corresponding rib of the bottom tube ring and is in the form of a semicircle with diameter equal to 0,05 R (m). This diameter is perpendicular to the bottom tube ring. The top part of the outer contour is a helical curve.

The inner contour of the turbine blade lies in a plane forming an angle from 60° to 90° with the plane which is perpendicular to the bottom tube ring and passes through the supporting rib. The inner contour also comprises a bottom and a top parts smoothly overflowing into one another. The starting point of the bottom part rests on the corresponding rib, sits at a distance equal to (0.1 - 0.15) R (m) away from the wind turbine axis and starts with a sector of a circle with radius from 0.518 to 0.549 R (m). At the end of this sector the bottom part transforms into a straight line which is tangential to the so described circular sector. This straight line ends into the respective rib of the top turbine round and has a length ranging from 0.371 to 0.865 R (m).

Given the function performed by the turbine blades, it is recommendable that they are made of a suitable plastic material, such as fibre glass plastic, polyethylene terephthalate or polycarbonate.

The vertical orientation of the turbine implies a simplified and reliable mechanics, regardless of the wind direction, reduced distances when positioning the turbines in windmill parks, minimized noise levels. The design provides maximum wind-driven surface per unit of volume, as the internal turbulence of the air drives the flow from one blade to another and thus yields further self-acceleration of the rotation.

At the same time, the design has as simplified as possible manufacturing technology ensuring low cost per unit of output. The design of this vertical- axis wind turbine is easy to assemble/disassemble and easy to transport due to the reduced volume it occupies.

Explanation of the figures

Sample embodiment of the invention is shown in the attached figures, where:

Figure 1 shows a supporting structure of vertical-axis wind turbine with single turbine unit.

Figure 2 - Vertical-axis wind turbine with single six-blade turbine unit.

Figure 3 - Supporting structure of vertical-axis wind turbine with two turbine units.

Figure 4 - Vertical-axis wind turbine with two turbine units - one with six blades and another unit with twelve blades.

Figure 5 - Schematic front view of the supporting structure of a vertical-axis wind turbine with four turbine units.

Figure 6 - Schematic top view of the supporting structure of a vertical-axis wind turbine with four turbine units.

Figure 7 - Front view of a turbine blade in operating state.

Figure 8 - Schematic view of a turbine blade.

Figure 9 - Vertical-axis wind turbine with three turbine units and attached electrical generator.

EXEMPLARY EMBODIMENT OF THE INVENTION

Figure 1 shows one alternative supporting structure design of a single-unit vertical-axis wind turbine with six blades attached to the turbine unit. The turbine unit ( 1) of this vertical-axis wind turbine on Figure 1 consists of a shaft (2) rotating around a longitudinal axis; pre-bent and equally sized top (5) and bottom (6) tube rings are fixed to the shaft ( 1) by means of load- bearing radial ribs (3) with length R (m) and distribution washers (4). The tube rings (5) and (6) are mounted perpendicularly to the axis of the shaft (2) at a specified distance from one another, which distance determines the height H (m) of the turbine unit ( 1). At the same time, the tube rings (5) and (6) are parallel to each other in a way that the radial ribs (3) (six per tube ring) are positioned exactly one above the other. The radial ribs (3) divide the top (5) and bottom (6) tube rings into six identical sectors each. In this particular case there are six turbine blades (7) attached between the top (5) and the bottom (6) tube rings - Figure 1 and Figure 2. Each of the turbine blades (7) is attached with its one end to a load-bearing radial rib of the top tube ring (5) and with its other end to the subsequent rib of the bottom tube ring (6). In operational position each of the turbine blades (7) has a complex spatial form defined by an outer (8) and inner (9) contour and by the corresponding ribs of the bottom (6) and top (5) tube rings to which the turbine blade (7) is attached.

Figure 3 presents a supporting structure of an alternative version of a double-unit vertical-axis wind turbine. The first turbine unit (1) has the same design as the previously described one and features two sets of six load-bearing radial arms (3), one for the top (5) and one for the bottom (6) tube rings.

The second turbine unit (10) comprises of two pairs of top tube rings concentric to one another and two bottom tube rings concentric to one another. These pairs of tube rings are set parallel to each other at a certain distance H (m) and perpendicularly to the shaft (2) of the vertical-axis wind turbine. The top inner turbine round (6) with radius R is identical to the bottom tube ring of the first turbine unit ( 1). The second outer tube ring (1 1) lies in the same plane as the top inner turbine round (6) and has radius of 2R (m). In addition to being connected by means of six supporting radial ribs (3), the outer ( 1 1) and inner (6) top tube rings are fixed also by six supporting ribs ( 12) arranged between the load-bearing radial ribs (3) in such a way as to form twelve identical radial sectors. The load-bearing radial ribs (3) are fixed, to the shaft (2) by means of the distribution washer (4) .

Similarly, the two bottom concentric rings of the second turbine unit (10) - the inner (13) and the outer (14) rings - have respectively radii of R (m) and 2R (m), lie in one plane and are connected to the shaft (2) by means of the load-bearing radial ribs (3) and the distribution washer (4). In between the load-bearing radial ribs (3) are positioned supporting arms (12) fixed to the two tube rings (13) and ( 14) in such a way as to from twelve identical radial sectors.

The mounting of the turbine blades (7) is identical to that described for the turbine blades (7) in a single turbine unit. Each of the turbine blades (7) is secured with its one end to the outer part of a load-bearing radial rib (3) or to a supporting rib (12) located between the inner tube ring (6) and the outer tube ring (1 1) of the top pair of tube rings, and with its other end to the part of the subsequent load-bearing radial rib (3) or supporting rib (12) located between the inner (13) and outer (14) tube rings from the bottom pair of tube rings.

As mentioned above, and as it may also be seen on Figure 4, this design of vertical-axis wind turbine features two turbine units (1) and (10), of which the first one is equipped with six turbine blades (7) and the second one - with twelve turbine blades (7).

Such a vertical-axis wind turbine may be assembled with one or more turbine units and each turbine unit may also have different number of turbine blades. However, it is preferable that the number of turbine units does not exceed four, and the number of blades per turbine unit does not exceed twenty four. The optional different number and type of turbine units, as well as their different positioning allows creating different layouts of wind turbines - with various turbine units each having different number of blades, and different positioning of the turbine units.

Table 1 presents the basic technical data of vertical-axis wind turbines with different combinations of the number and type of turbine units. The letter "a" denotes a vertical-axis wind turbine with six blades, "b" - 12 blades, "c" - 18 blades, "d" - 24 blades; D (mm) designates the diameter and H (mm) - the height of the turbine. The following figures present schematic front view (Figure 5) and top view (Figure 6) of the supporting structure of a four-unit vertical-axis wind turbine. The principle of design of the turbine units is the same as the above described for a two-unit turbine. The uppermost turbine unit (1) has two sets of six radial ribs for each of its top and bottom tube rings and, respectively, six turbine blades; the subsequent turbine unit ( 10), viewed from top to bottom, has 12 ribs in total - with equal number of load-bearing radial ribs and supporting ribs on each of its tube rings and with 12 turbine blades. The third turbine unit (15) from the top has 18 blades respectively and the last turbine unit (16) has 24 blades.

Figure 7 shows front view of a turbine blade (7) in operational state and Figure 8 provides a schematic view of a turbine blade (7).

Table 1

No. Combination D (mm) H (mm) Number of Aggregate

turbine turbine blades area of the diameter height turbine

(m ² )

1. a 2,000 1 , 146.6 6 8.4

2. a- a 2,000 2,293.2 12 16.8

3. a-b 4,000 2,293.2 18 25.2

4. a-b-a 4,000 3,439.8 24 33.6

5. a-b-b 4,000 3,439.8 30 42

6. a-b-b-a 4,000 4,586.4 36 50.4

7. a-b-c 6,000 3,439.8 36 50.4

8. a-b-c-b 6,000 4,586.4 48 67.2

9. a-b-c-b-a 6,000 5,733 54 75.6

10. a-b-b-c 6,000 4,586.4 54 75.6

1 1. a-b-c-c-b 6,000 5,733 66 92.4

12. a-b-c-c-b-a 6,000 6,879.6 72 100.8

13. a-b-c-d 8,000 4,586.4 60 84

14. a-b-c-d-c 8,000 5,733 78 109.2

15. a-b-c-d-c-b 8,000 6,879.6 90 126

16. a-b-c-d-c-b-a 8,000 8,026.2 96 134.4 No. Combination D (mm) H (mm) Number of Aggregate

turbine turbine blades area of the diameter height turbine

(m ³ )

17. a-b-c-d-d 8,000 5,733 84 1 17.6

18. a-b-c-d-d-c 8,000 6,879.6 102 142.8

19. a-b-c-d-d-c-b 8,000 8,026.2 1 14 159.6

20. a-b-c-d-d-c-b-a 8,000 9, 172.8 120 168

Each one of the turbine blades (7) on Figure 8 in operational position has a complex spatial form defined by an outer (8) (AIB IC I) and an inner (9) (A2B2C2) contours and by the corresponding supporting ribs A1A3 of the bottom and C 1C3 of the top tube rings to which the turbine blade (7) is attached. Al and C I are the outermost points respectively of the supporting ribs A1A3 and C 1C3, and A3 and C3 are the innermost points of the supporting ribs A1A3 and C 1C3. The supporting ribs A1A3 and C 1C3 are not located exactly one above the other, but are adjacent relative to the vertical, so that when C 1C3 stands to the left of A1A3 the turbine unit rotates counter clockwise, and vice versa - when C 1C3 stands to the right of A1A3 the turbine unit rotates in a clockwise direction.

The outer contour (8) (AIB IC I) of the turbine blade (7) represents a spatial curve which begins from the supporting rib A1A3 of the bottom tube ring. This spatial curve comprises a bottom AlB l and a top B lC l part smoothly overflowing into one another. The bottom part AlB l of the spatial curve starts at point Al of the bottom tube ring and is in the form of a semicircle with diameter equal to 0,05 R. This diameter is perpendicular to the bottom tube ring.

The top part of the outer contour, which starts at point B 1 and ends at point CI, is a helical curve.

The inner contour (9) (A2B2C2) of the turbine blade (7) lies in a plane F forming an angle from 60° to 90° with the plane G which is perpendicular to the bottom tube ring and passes through the supporting rib A1A3. The inner contour A2B2C2 comprises a bottom A2B2 and a top B2C2 parts smoothly overflowing into one another. The starting point A2 of the bottom part A2B2 rests on the supporting rib A1A3, point A2 sits at a distance equal to (0.1 - 0.15) R (m) away from the wind turbine axis. From point A2 starts a sector of a circle with radius from 0.518 to 0.549 R (m). At the end of this sector, i.e. point B2, the bottom part transforms into a straight line which is tangential to the so described circular sector. This straight line ends at point C2 of the supporting rib C 1C3. The length of the straight line B2C2 ranges from 0.371 to 0.865 R (m).

Given the function performed by the turbine blades, it is recommendable that they are made of a suitable plastic material, such as fibre glass plastic, polyethylene terephthalate or polycarbonate.

Figure 9 shows a vertical-axis wind turbine with three turbine units and an attached turbine-driven electrical generator ( 17).

Principle of operation

The designed vertical-axis wind turbine is intended to convert the wind energy into a spinning motion of the rotating shaft of the electrical generators for direct and alternating current.

The airflow enters into the inside of the turbine through the open spaces formed between two adjacent outer lines forming the shape of the contour of the turbine blade (7). Unlike the existing designs operating at wind speeds > 3 m/s, this turbine starts rotating at wind velocity > 2 m/ s, ensuring the necessary torque depending on the chosen electrical generator whose power determines the necessary combination of turbine units. One third of the turbine blades (7) of the turbine units, for instance with area of 1.5 m ² , arranged radially to the turbine's axis, take the direct hit of the wind front. The remaining 2/3 of the turbine blades (7) that are not located into the core (active) zone only accelerate their rotational motion, transferring part of the airflow from one blade to another along their inner concave surface. The outer streamlined surface of the turbine blades (7) minimizes the turbulence after the edge of each blade and in the zone of the active wind flow acts as a diffuser, so that the primary air flow slides down along the inner surface of each turbine blade and gets out through the triangular openings formed between two adjacent ribs of the bottom tube ring.