CN101099040B - Vertical axis turbine apparatus - Google Patents

Abstract

Vertical axis turbine apparatus is described in which a rotating blade turbine member mounted on a fixed base consists of one to fifty, preferably two or three, upwardly and outwardly inclined spars (F). On each spar is set at least one aerofoil or hydrofoil section blade (S). If there is more than one spar, the spars are preferably held to one another via a plurality of guy wires (T).

Description

A vertical axis turbine device

technical field

The present invention relates to a vertical axis turbine, in particular to a vertical axis turbine for, but not limited to, power generation.

Background technique

It has been known for centuries that energy can be obtained from wind power. Windmills are a well-known feature in medieval landscape painting in many countries, and even today they are used on various occasions around the world. Power generation is a particular application of wind turbines.

With growing concerns about the depletion of fossil fuels and the possible adverse environmental impacts of their use, the possibility of generating electricity from wind turbines, especially on a large scale, is attracting renewed interest.

So-called "wind farms" have been built in many countries to harvest wind energy in this way. A "wind farm" generally consists of a row of towers, each with a rotatable top for aligning with the wind, on which are mounted a number of turbine blades, which, like propeller blades, are all aligned with the A rotary shaft connection. But the difference is that the propeller blades are driven by the engine, and these turbine blades are driven by the wind, which creates forward thrust. A large amount of literature has been published on such horizontal axis wind turbine installations.

While commercial power generation from such devices has begun, some observers worry that the installation would be an eyesore when it sits in a rural setting. Offshore wind turbines reduce the impact on the landscape and deflect objections to the sheer size and number of installations. By increasing the size of offshore wind turbines, the number of wind turbines needed to provide a given power can be reduced, thereby reducing the cost of electrical connections to shore.

Fatigue damage (eg "metal fatigue") caused by repetitive bending and flipping of the blade due to its weight as the blade rotates limits the size of horizontal axis wind turbine installations. Assuming no other improvements are made in the design, the fatigue damage caused by the blade weight increases proportionally with the blade size. As the size of the blades becomes larger, designers have to use different materials with better fatigue resistance, but these materials are usually more expensive, thus reducing the cost efficiency of the device.

Wind turbine installations with blades rotating about a vertical axis are not subject to reverse bending due to weight, but are subject to fatigue damage due to wind pressure loads. However, wind pressure fatigue does not increase with the size of so-called vertical axis wind turbine installations and therefore does not impose a limit on their size.

Many proposals have been made in the past to generate electricity using vertical axis wind turbines. There is extensive literature dealing with so-called Savonius designs and Darrieus designs, and practical generating units have also been built. However, generating electricity from vertical-axis wind turbines has not gained traction with commercial wind farm operators due to lack of well-developed technology. The reason for the lack of development of vertical axis wind turbines is that vertical axis wind turbines are generally considered to operate less efficiently than horizontal axis turbines.

GB-A-2102079 describes a vertical axis wind turbine having twin blades inclined upwards at a selectable angle relative to the horizontal, the bottom ends of which are connected to a shaft allowing it to wind around a vertical axis rotate. This design has not undergone any commercial development. This design has the disadvantage of generating wind pressure which can cause excessive tipping or overturning moments of the entire unit. The cost of anti-overturning moment is uneconomical.

GB-A-2303409 discloses a similar vertical axis wind turbine consisting of balanced tilted individual blades rotating about a vertical axis which, under wind pressure, can swing in the direction. This design reduces the overturning moment, but requires heavier blades and balancing masses, and is less economical.

Turbine devices for extracting electricity from running water are also well known, from medieval waterwheels to more modern designs of turbines called hydroelectric power installed underwater to extract electricity from a flow of water.

Contents of the invention

We provide a novel design of a vertical axis turbine that can increase the size of the vertical axis turbine beyond the size of an economically viable horizontal axis turbine. The vertical axis turbine can be used as an onshore or offshore wind turbine or underwater to extract electrical energy from a fluid.

According to one of its broadest aspects, the present invention provides a vertical axis turbine comprising a fixed base and a turbine member having blades mounted on the fixed base and rotatable about a vertical axis, the bladed The structure consists of at least one obliquely elongated spar inclined outwardly from the axis of rotation, on which or on each spar at least one blade of short airfoil or hydrofoil section is arranged. Preferably, the angle of the short airfoil or hydrofoil section blades to the spar is adjusted to optimize the total rotational couple about the vertical axis and minimize the total tilting moment when the turbine is subjected to wind or water flow loads. When there is more than one blade, the angles between all the blades and the spar can be different. As the structural support for the airfoil or hydrofoil shaped part, the elongated spar must bear the load on its own, therefore, the spar preferably has an airfoil or hydrofoil shaped section to minimize drag.

Preferably the number of said spars is 2 or 3, but up to 50 said spars may be provided if desired. If there is more than one spar, preferably the plurality of spars are held together by cables or the like connecting each spar to the opposite or adjacent spar . The angle of inclination of each spar relative to the vertical is adjustable, eg, by hinged bases of each spar to adjust the angle of inclination by shortening or lengthening the cables. Preferably, the number of short airfoil sections or hydrofoil shaped elements is between 1 and 20, more preferably between 2 and 5, most preferably 4.

The airfoil or hydrofoil profile of blades and spars, ie their leading edge to trailing edge profile, can differ in their classification, thickness-to-chord ratio, and arch shape. For wind turbines, the aerodynamic profile of the blade preferably has a maximum thickness-to-chord ratio of between 10% and 50%.

The aspect ratio of each of said short airfoil or hydrofoil section blades is preferably between 2 and 5, but most preferably between 3 and 4.

The mounting angle of the short airfoil or hydrofoil section blade on the or each spar is preferably between 90° and 160°, but most preferably about 145°.

The length of each of said short airfoil or hydrofoil section blades on the spar is measured from a horizontal line in the normal cross-sectional plane of the short blade perpendicular to the radially vertical plane including the centerline of the spar. The installation angle, ie the inclination angle, is preferably between +5° and -5°. The installation angle of each blade can be the same or different. The angle should be adjusted to maximize the efficiency of the turbine in harvesting power from wind or water flow, but this angle adjustment can be used for other purposes as well. For example, by changing the inclination angle of one or more short airfoil or hydrofoil blades in a gradual manner, the inclination angle can be changed by up to 90° to achieve aerodynamic or hydraulic braking. Effect. This is invaluable for efficiently controlling the turbine, for example in the event of high winds or floods, using the aforementioned angle adjustments to limit output power. Additionally, one or more of said short airfoil or hydrofoil sections may include a device that can cycle like an airfoil from +90° to -90° about a spanwise hinge Rotate the rearmost portion of the blades to maximize the power output of the turbine.

The size of the turbine of the present invention can vary widely, and of course the larger the size of the turbine, the greater the power it can generate. Typical dimensions of a wind turbine with a design capacity of 1 MW are: the diameter of the circle swept horizontally by the outer edge of the spar is 100 meters, the spanwise length of the blades is 16 meters, and the chord length is 5.5 meters.

The structure of the vertically sloping spars can vary widely, from simple, with a single central spar extending outwardly upwards, to complex, such as a frame of many sub-spars, the frame For mounting individual short airfoil or hydrofoil section blades. Preferably, the cross-section of the spar and any other members such as struts or their connecting straps are airfoil or hydrofoil-shaped in order to minimize drag. Under this condition, various designs can be adopted.

Description of drawings

The present invention will be further described in detail below with reference to accompanying drawing and by embodiment, wherein:

1 is a perspective view of a vertical axis wind turbine device of the present invention;

Fig. 2 is a vertical axis section of the device shown in Fig. 1;

Figure 3 is a schematic perspective view of another embodiment; and

FIG. 4 is a full vertical section through the embodiment of FIG. 3 .

Detailed ways

Referring initially to Figures 1 and 2, there is shown a wind turbine installation having two arms F connected by guy cables T, the arms F comprising independent spars supporting short Blade S of airfoil section.

The bases of the two spars F are joined together at an axis H rotatably arranged on the base B. As shown in FIG. As the wind blows, the assembly arms F, blades S and cables T rotate about a vertical axis on the base B and a suitable type of generator means can be driven by a suitable shaft through a transmission or, preferably, can be driven by the shaft Directly drives an appropriate type of generator unit. The overall size of the turbine device shown in Fig. 1 and Fig. 2 can vary in a wide range, the larger the size of the turbine device, the greater the engineering expenditure, but the greater the power generated by its rotation.

Referring now to Figures 3 and 4, there is shown a wind turbine arrangement having two arms comprising a complex structure of struts and connecting straps supporting a blade S of short airfoil section. frame.

Each strut and connecting strip forming an arm or spar has an airfoil-shaped cross-section to minimize wind resistance. As shown in the figures, the leading edges of each airfoil are in the same circumferential direction as seen around a vertical axis passing through the center of the device, so that when the wind blows horizontally through the device, the turbine device of the present invention follows the direction of Fig. 3 Rotate in the direction of rotation represented by R.

As can be easily seen in Figure 3, the two arms are built on a substantially cylindrical base B. As can be seen from the figure, the two arms are respectively rotatably connected at their bases to a pair of mounting lugs so that after the three struts marked F' have been disengaged, each arm can be rotated around a A roughly horizontal axis of rotation. This is very useful, for example, to make it possible to repair any airfoil damage caused by a bird's collision.

The base B is mounted on a suitable bearing system and provides means to directly or indirectly drive a generator to generate electricity when wind blows through to rotate the assembly shown in Figures 3 and 4 .

An underwater turbine arrangement can be made in a similar manner, but take into account the conditions that may be encountered. Through careful design, the effective weight of rotating turbine components can be greatly reduced by, for example, manufacturing hollow hydrofoil-shaped components, thereby greatly saving engineering costs.

Claims (12)

1. A vertical axis turbine comprising: base; and a turbine member mounted to the base for rotation about a vertical axis relative to the base, the turbine member comprising: at least one obliquely elongated airfoil or hydrofoil-shaped spar mounted with its lower end to the base and inclined upwardly and outwardly from the axis of rotation; and Each spar is provided with at least one blade of airfoil or hydrofoil section; wherein the blades of each airfoil or hydrofoil section are inclined downwardly or outwardly with respect to the axis of rotation; and The blades of each airfoil or hydrofoil section are mounted to generate an aerodynamic or hydrodynamic lift force against the tilting moment generated by the spar when the turbine is operating in a fluid flow. 2. The turbine according to claim 1, characterized in that the blades of the airfoil or hydrofoil section are mounted on each spar at an angle in the range of 90° to 160°, the angle being inclusive of the The centerline of the spar is measured radially in the vertical plane from the radially outward horizontal direction. 3. A turbine according to claim 1 or 2, characterized in that the blades of each airfoil or hydrofoil section are mounted to the spar at an angle in the range of +5° to -5°, which is Measured in the normal cross-sectional plane of the short blade from a horizontal line perpendicular to a radial vertical plane including the centerline of the spar. 4. The turbine of claim 1 wherein each airfoil or hydrofoil section blade has a first blade portion extending downwardly and outwardly from the spar and a first blade portion extending upwardly and outwardly from the spar. An inwardly extending second blade portion. 5. The turbine of claim 1, wherein the number of spars is two or three. 6. The turbine of claim 1 wherein the number of blades of airfoil or hydrofoil section on each spar is from one to five. 7. The turbine of claim 1, wherein each airfoil or hydrofoil section blade has an aspect ratio in the range of 2 to 5. 8. A turbine as claimed in claim 1, comprising two or more spars, and further comprising a plurality of cables or the like connecting each spar to an opposing or adjacent spar. 9. The turbine of claim 1 wherein the angle of inclination of the spar is variable. 10. A turbine as claimed in claim 9, wherein each spar is hinged to a base member for rotation about a horizontal hinge axis to vary the angle of inclination. 11. The turbine of claim 1, wherein the spar is formed of a plurality of sub-spars forming a frame for mounting individual short airfoil-section blades. 12. The turbine of claim 1, wherein the turbine is configured as a wind turbine, and wherein the aerodynamic profile of the blade has a maximum thickness-to-chord ratio in the range of 10% to 50%.