WO2014114389A1

WO2014114389A1 - Air turbine for using energy from the sea

Info

Publication number: WO2014114389A1
Application number: PCT/EP2013/074809
Authority: WO
Inventors: Christoph Moisel; Thomas Carolus; Hans-Ulrich Banzhaf; Frank Biskup; Raphael Arlitt; Matthias Arnold
Original assignee: Voith Patent Gmbh
Priority date: 2013-01-22
Filing date: 2013-11-27
Publication date: 2014-07-31
Also published as: DE102013000989B3; EP2948650A1

Abstract

The invention relates to a bidirectional air turbine, comprising the following features and components: - a rotor having a rotor disc, which rotor disc bears a number of rotor blades; - a shaft rotationally fixed to the rotor; - a housing, which together with the rotor forms a chamber through which flow occurs; - the chamber through which flow occurs has a channel segment through which axial flow occurs, a bend, and a channel segment through which radial flow occurs and which has a radial opening; - a dome-like flow-guiding body coaxial with the axis of rotation of the shaft, a base region of the flow-guiding body lying near or on the rotor disc and a tip region of the flow-guiding body pointing toward the axial opening; - a number of guide vanes borne by the housing. The invention is characterised by the following features: - the axial extent of the flow-guiding body is at least twice as large as the axial extent of the rotor blades; a number of guide vanes borne by the housing.

Description

Air turbine to exploit energy from the sea

The invention relates to an air turbine for exploiting ocean energy and for converting the energy into electrical energy. Such systems have become known, for example, from EP 0 000 441 A1 and GB 2 250 321 A. It is therefore a facility that exploits sea-level motion due to surface waves.

Systems of this type are constructed as follows: They comprise a chamber which is open at its lower end and with this open end immersed in the sea. At its upper end, it also has an opening. There is further provided a pipe which serves to guide an air flow. The tube is connected with its one open end to the upper opening of the chamber. In the tube is an enclosed by this and coaxial with the tube arranged energy unit with a turbine rotor and possibly with a standing in driving connection with the rotor electrical generator.

The mirror of the sea water within the chamber constantly rises and falls according to the waves of the sea; the wave motion thus acts into the chamber. With each lifting of the water level, a displacement of the air quantum in the chamber is contained. The air is displaced when lifting the water level and flows through the upper opening of the chamber and thus also through the pipeline in which the turbine is located.

Conversely, when lowering the water level, air from the free environment is drawn into the chamber via the pipe. The periodically changing air flow in its direction drives the turbine, and thus also the electric generator, which as such generates electrical energy.

The turbine is thus an air turbine. It has a rotor with a

Rotor disc on. The rotor disk carries a number of blades. One Housing together with the rotor flows through a space. This space has an axially flowed through channel and a radially flowed channel. See GB 2 125 113 A. The turbine is flowed through in two directions, corresponding to the raising and lowering of the seawater level. The

The direction of rotation of the turbine remains unchanged.

The efficiency of such turbines is not optimal. This goes back to the following: If the turbine flows through radially-axially, it results in the

Exit area of the turbine a flow with high swirl. This lowers the efficiency of the turbine.

If the turbine flows through in an axial-radial direction, flow separations occur in the area of the radial flow guidance, which also increases the efficiency

reduce.

The invention has for its object to design a turbine according to the preamble of claim 1 such that the efficiency over the

The art is significantly improved. This object is solved by the features of claim 1.

The prior art and the invention are explained in more detail with reference to the drawing. Therein, Figures 1 and 2 illustrate the prior art, all other figures illustrate the invention.

The figures show a known air turbine in a schematic representation, namely Figure 1 in an axis-parallel section, and Figure 2 in an axial section.

The inventive meridian contour shown in FIG. 3 comprises the following components or features: A rotor 1 comprises a rotor disk 2. This is rotatably with a shaft 3. The rotor disk 2 carries a plurality of rotor blades 4.

It can be seen a dome-like Stromleitkörper 5 with a foot area 5.1 and a tip area 5.2. The Stromleitkörper 5 thus extends parallel to the axis of rotation. It is firmly connected to the housing 6, for example via

Vanes. But it can also be firmly connected to the shaft 3, and then circulate with it. The Stromleitkörper can also be shared. Foot section 5.1 is then connected to shaft 3 in a rotationally fixed manner, while top section 5.2 is supported by the guide wheels.

A housing 6 forms an axial together with the Stromleitkörper 5

Radially outside the blade 4, the housing forms a radially flowed through channel section 9. This is followed by a cranked channel section 10, which flows in the radial direction, but has a small axial component (hereinafter referred to as "inclined Channel ").

In the axially flowed through channel section 7 is a variety of

Vanes 11. These are supported by the housing 6.

If the turbine flows through radially-axially, that is, air enters the inclined channel section 10, turbulence of the air as it enters the axial channel is avoided. This is achieved by the shape of the Stromleitkörpers 5. This is extremely long. Its length, from the foot area 5.1 to the

Peak area 5.2, is a multiple of the axial extent of

Blade 4. In the present case, the Stromleitkörper 5 is about four times as long as the blade is wide. It should be at least twice as long as the blade is wide. The ratio may be, for example, 3: 1, 4: 1, 5: 1, 6: 1, 7: 1 or more. As can be seen, the entire area through which it flows comprises the following

Channel sections: An axially flowed through channel section 7, a manifold 8, a purely radially flowed through channel section 9, and an inclined

Channel section 10. The flow is there predominantly radially, with a small axial component.

The vane 11 provides a firm connection between the housing 6 and

Stromleitkörper 5. The axially flowed through channel section 7 is formed as a diffuser. This also applies to the inclined channel section 10.

Stromleitkörper 5 reduces or avoids turbulence of the flow in the axial region. It reduces the cross section in the channel section 7 and therefore increases the flow rate. This reduces the occurrence of so-called dead water.

The stator also contributes to this.

The design of the sloped channel avoids backflow, which in turn reduces flow losses.

FIGS. 4 to 11 show further embodiments.

The embodiment according to FIG. 4 in turn has a guide blade 11 in the axially through-flowed channel section 7, but no guide blade radially outside the moving blade 4.

By contrast, the embodiment according to FIG. 5 also has a guide blade 12 in the channel section 9 through which it flows radially. The embodiment according to FIG. 6 has a guide blade 13 in the region of the bend 8.

The embodiment according to FIG. 7 in turn has a guide blade 13 in the region of the bend. Further, a guide vane 12 in the radially flowed through channel section. 9

The embodiment according to FIG. 8 has a guide blade 13 in the region of the bend, but close to the moving blade 4.

The embodiment according to FIG. 9 has a guide blade analogous to that in FIG. 8, as well as a guide blade 12 in the radial channel.

The embodiment according to FIG. 10 has a guide blade 11 in the channel section 7, which flows through axially. The axial channel section 7 is curved approximately S-shaped.

The embodiment according to FIG. 11 has the same structure as that according to FIG. 10. However, in this case, in the radial channel section 9 there is again a guide blade 12.

As shown in Figures 10 and 11, the Stromleitkörper 5 contours

have, which differ from a cylindrical contour. He can be club-shaped. He may have constrictions and extensions. He may even have a waveform as a contour - not shown here.

FIGS. 12 to 15 serve above all to illustrate embodiments of the radially through-flowed channel region. In Figures 12 and 13, the housing 6 and a housing wall 6.1 is bent. In the embodiment according to FIG. 12, the bend is located directly radially outside the rotor blades 4, in the illustration according to FIG. 13 somewhat further radially outwards.

In the embodiments according to FIGS. 14 and 15, the inclined channel section 10 is illustrated, starting immediately radially outside the blade 4 in FIG. 14, and slightly radially outside in the embodiment according to FIG.

In addition to the above, the following configuration is possible:

The contour A of the rotor disk and the contour B of the housing or the contour of a cover disk C are designed such that the width X of the radial

flowed through rotor surface increases from outside to inside.

The following configuration is also possible:

flowed through rotor surface from outside to inside initially decreases and then increases again.

Reference number list

1 rotor

2 rotor disk

3 wave

4 blade

5 Stromleitkörper

5.1 foot area

5.2 Tip area

6 housing

6.1 Housing wall

7 axially flowed channel section

8 elbows

9 radially flowed channel section

10 inclined channel section

11 vane

12 vane

13 vane

14 vane

15 vane

Claims

claims

1. Bi-directional air turbine comprising the following features

or components:

1.1 a rotor (1) with a rotor disc (2) having a number of

Carrying blades (4);

1.2 one with the rotor (1) rotatable shaft (3);

1.3 a housing (6) which forms a flow-through space together with the rotor (1);

1.4 the space flowed through has an axially flowed through the channel section (7), a manifold (8) and a radially flowed through channel section (9) with a radial opening;

1.5 a to the rotation axis (3) of the shaft coaxial dome-like Stromleitkörper (5) whose foot region is close to or on the rotor disc (2) and its tip region (5.2) points to the axial opening;

characterized by the following features:

1.6 the axial extent of the Stromleitkörpers (5) is at least twice as large as the axial extent of the blades (4).

1.7 a number of vanes (11-15) carried by the housing (6);

2. Bi-directional turbine according to claim 1, characterized in that the ratio of the axial extents of Stromleitkörper (5) and

Blade (4) that is three, or four, or five, or six, or seven, or eight, nine, or ten times, or a value between those values.

3. Bi-directional turbine according to claim 1 or 2, characterized in that the guide vanes (11) are arranged in the axially flowed channel section.

4. Bi-directional air turbine according to one of claims 1 to 3, characterized in that guide vanes (13) in the region of the manifold (8) are arranged.

5. Bi-directional air turbine according to one of claims 1 to 4, characterized in that guide vanes (12) in the radially flowed through channel section (9) are arranged.

6. Bi-directional air turbine according to one of claims 1 to 5, characterized in that at least part (10) of the radially flowed through channel section (9) is inclined against the radial direction.

7. Bi-directional air turbine according to one of claims 1 to 6, characterized in that the Stromleitkörper (5) stands still.