EP2691633A1

EP2691633A1 - Power plant for obtaining energy from a flow of a body of water, and method for the operation thereof

Info

Publication number: EP2691633A1
Application number: EP12709521.4A
Authority: EP
Inventors: Norman Perner; Jochen Weilepp
Original assignee: Voith Patent GmbH
Current assignee: Voith Patent GmbH
Priority date: 2011-03-28
Filing date: 2012-03-09
Publication date: 2014-02-05
Also published as: KR20140014201A; CA2828148A1; DE102011015335A1; WO2012130386A1; US20140037449A1

Abstract

The invention relates to a power plant for obtaining energy from a flow of a body of water with a varying main incident flow direction, comprising a rotating unit with an axial turbine which is assigned an axis of rotation and which comprises at least one rotor blade; wherein the rotor blade is fastened in a rotationally conjoint manner to a rotor head of the rotating unit; and wherein the rotor blade has, at least over a partial region of the longitudinal extent thereof, a profile which can be impinged on by flow bidirectionally for windward and leeward operation. The invention is characterized in that a rotary device is provided for a power plant component for adjusting a relative angle between the axis of rotation and the main flow direction, wherein the rotary device is assigned a first stop and a second stop which limit the range of movement of the rotary device to a range of angle of rotation of less than 180°.

Description

Power plant for generating energy from a stream of water and method for its operation

The invention relates to a power plant according to the preamble of claim 1 for the production of energy from a stream of water with a varying

Main flow direction, in particular a tidal flow, and a method for its operation.

For the adaptation of tidal power plants to a cyclical change of the

Direction of flow in the course of ebb and flow, different concepts have been proposed. One way, for example, by the

GB 2347976 A, is to rotatably fix the rotor blades of an axial turbine to a hub and to perform a 180 ° rotation about the longitudinal axes of the rotor blades for the tidal exchange. The advantage of this approach is that efficient rotor blade profiles designed for unidirectional flow can be used. However, the increased

Blade angle adjustment mechanism the complexity of the rotor blade connection. In addition, the controller for the blade angle adjustment must work very reliable because _. Incorrect flow can lead to serious system damage.

Another, the use of a unidirectionally inflatable rotor blade profile enabling plant concept for tidal power plants to adapt to the Tidenwechsel consists in a total tracking of the turbine-bearing component. Typically, this is a nacelle housing with the

Storage device for an axial turbine. Known is the concept of wind power - this reference is made by way of example to the US 2008/0111379 AI, with a rotating device for the nacelle housing of a tidal power plant must perform a rotation of 180 °. The rotary drive used for this purpose can be done, for example, electrically or hydraulically. It is also conceivable to use an external drive in the form of a thruster, the forces on initiating a nacelle housing - this is referenced, for example, to US 2010/0038911 AI. Also conceivable is the use of a passive-acting

Turning device, for example by means of a leeward arrangement of the axial turbine. In the case of a windward design disclosed, for example, in DE 1020090116152 A, fin-shaped, leeward-lying flow guide surfaces are necessary for aligning the installation.

The known devices for the total tracking of an axial turbine for a tidal power plant either allow a rotational movement of the

Machine nacelle about a vertical axis or a rotation about a substantially horizontal axis. For the latter, reference is made to DE 10 2007 013 293 A1 and GB 2 431 207 A. For both configurations is the

Rotary device associated with a rotation angle range of at least 180 ° to allow the operation of the system with incoming and outgoing tidal flow.

Another plant concept for tidal power plants is based on a stationary plant with rotor blades articulated rigidly on an axial turbine. Adaptation to the tidal change is effected by a bidirectionally inflatable profile of the rotor blades. For this purpose, double-axis symmetric elliptical profiles can be used. This is on the

WO 2006/125959 AI referenced. An alternative are profiles with a

Point symmetry and a vault, so that the skeleton line an S-beat follows - this is referred to the US 2007/0231148 AI. The use of torsionally rigidly hinged rotor blades with bidirectionally inflowable profiles leads to robust and low-maintenance systems, since additional storage and

Drive components for a rotary device used for tracking can be dispensed with.

The invention is based on the object, a power plant for generating energy from a stream of water whose flow direction is temporally variable, specify that has a low-maintenance design. In addition, the power plant should efficiently use a directionally variable stream of water

Use energy generation and at the same time have a structurally simple Abregelung for the overload case.

The object underlying the invention is solved by the features of the independent claims. According to the invention, a system with a bidirectionally flowable axial turbine with rotationally fixedly articulated rotor blades, which has a bidirectionally flow-in profile for the combined windward and leeward operation, is combined with a rotary device which does not complete

Direction reversal allows and instead causes only a partial rotation.

Accordingly, the power plant operates in cyclic alternation in windward and in the Leebetrieb and the relative angle between the axis of rotation of the axial turbine and Hauptanströmungsrichtung is tracked only in a limited rotation angle range less than 180 ° to asymmetries of Tidenzykluses or

compensate for meteorological induced flow variations. In addition, the rotating device allows for adjusting the relative angle between

Rotation axis and main flow direction in case of overload a

System control by the relative angle is guided to the predetermined by stops maximum angle deviation.

The rotating device has a first stop and a second stop for limiting the angle of rotation to an angular range of less than 180 °. As a result, the control device can be simplified structurally, since a malfunction of the rotary device is not a fundamental

Incorrect flow of designed for the windward and leeward operation rotor can lead. Therefore, a failure of the rotating device does not endanger the entire system. In addition, resulting from the inventively provided partial rotation in a rotation angle range smaller than 180 °, a constructive simplification of the drives and the storage for the rotating device. Thus, the linear movement of a hydraulic cylinder can be used by means of a mechanical deflection to perform a rotation by a limited angular range. In addition, rudders and fins on the nacelle to drive the

Turning serve, without that they have a large projecting length in the leeward direction, as by the stops of the rotating device, the rotatable

Power plant component by the specification of a limited rotation angle range can not be completely wrong to the flow. To the execution of the

Rotary drive as possible to simplify the rotation angle range of

Turning device as narrow as possible and adapted to the plant location. For a preferred embodiment, the rotation angle range is less than 90 ° and particularly preferably less than 60 °. Further, the first and second stops are preferably set according to the asymmetry of the tidal flow at the plant site. For asymmetric tidal ellipses with an angular deviation of less than 30 ° from the 180 ° relative position for the averaged directions at low tide on the one hand and high tide on the other hand, a rotation angle range is less than 45 ° advantageous because the system tracked to the main Hauptanströmungsrichtungen and the rotating device structurally simple can.

For a preferred embodiment, the rotating unit with the

Axial turbine mounted on a nacelle and arranged the rotating device between the nacelle and the support structure. Accordingly, the moving of the rotating device within the predetermined rotation angle range

Power plant component the engine nacelle. Accordingly, the

Rotary axis of the axial turbine adjusted relative to the direction of flow. As flow direction while a Hauptanströmungsrichtung is assumed, which represents an averaging of the flow field in the rotor circuit of the axial turbine. A possible embodiment of the rotating device comprises a rotation axis which extends horizontally and which is perpendicular to the axis of rotation of the axial turbine. For an embodiment with a nacelle and an axial turbine mounted thereon, it is possible by a limited tilting movement of the nacelle, the axis of rotation of the axial turbine of the

Main direction of flow away, in order to plant shutdown the

Change rotor characteristic. For this purpose, a preferred

Overload detection device used at the power plant with a

Control device for the rotating device is in communication.

For efficient energy utilization at a location with an asymmetrical Tidenellipse a rotary device with a vertically extending and perpendicular to the axis of rotation of the axial turbine axis of rotation is preferred. This makes it possible to compensate for a weather-related variation of the main flow direction as well as site-specific directional deviations of an incoming or outgoing tidal flow, which are caused by the relief at the water bottom. For this purpose, the power plant comprises a flow measuring device for determining the currently present main flow direction, which communicates with a control device for the rotary device.

Distributed sensors and / or volume measurement methods are preferably used for the flow measuring device in order to be able to detect the flow conditions over the entire area swept by the rotor or to estimate them with sufficient accuracy. For this purpose, a sonar, an ultrasonic Doppler profile flow meter (ADCP) or a laser Doppler anemometer in question. Further, for measuring the flow field, vortex flowmeters,

Back pressure pipes, differential pressure sensors or indirect measuring systems such as

Strain gauges are used at the areas acted upon by the flow. The sensory components are preferably arranged around the plant or on stationary plant parts, such as the support structure. she However, they can also be placed on moving system components such as the hood of the rotor, the coupling connection to the tower or the machine nacelle. Furthermore, the measured values are averaged on a time scale of several minutes and examined for the occurrence of flow anomalies, such as the formation of vertebrae. In addition, a location-adapted tidal model can be stored for controlling the turning device. This is based on a tide prediction, based on the lunar calendar for the present

Location refined by site-specific fixes. The

Site-specific corrections can be determined during operation from the accumulated actual flow data. It is also conceivable to use data from the energy production of the plant and the times at which the plant standstill occurs to determine the correction factors. In addition, a control of the rotating device is conceivable, which aligns the system so that the output power is optimized. For this an MPP controller can be used.

For a further embodiment of the invention is carried out by the rotating device no change in position of the axis of rotation of the axial turbine relative to the stationary system. Instead, the rotary device stands with a power plant component in

A compound associated with a flow surrounding the axial turbine flow housing. The starting point is therefore a shell turbine with an axial turbine enclosed by a flow housing. Preferred is a movable design of the inflow and outflow areas of the

Flow housing, so that this relative to a varying

Main flow direction are adjustable. Also conceivable is the rotation of the entire flow housing or a rotation of components of the axial turbine upstream or downstream nozzle. According to the invention, the angle of rotation for the respective power plant component is on an angular range is limited to less than 180 °, so that the flow at the axial turbine reverses in a Tidenwechsel.

The invention will be explained in more detail below on the basis of exemplary embodiments in connection with figure representations, which represent the following:

1 shows an inventive power plant according to the sectional view A-A of Figure 2.

Figure 2 shows an embodiment of a power plant according to the invention in

Side view.

FIG. 3 shows an asymmetrical tidal ellipse.

Figures 4a, 4b show the power plant of Figure 1 for different

Anströmungsbedingungen.

Figures 5a, 5b show an alternative embodiment of an inventive

Power plant in side view in normal operation and in

Overload position.

FIG. 2 schematically shows in simplified form a power plant according to the invention

Side view. Shown is a mounted on a nacelle 8

Axial turbine 4. In this case, the axial turbine 4 has a horizontal axis of rotation 5, which is aligned parallel to the main flow direction 2. The

Main flow direction 2 represents a velocity-weighted averaging of the flow in the region which is defined by the rotor circle of the axial turbine 4. As sketched by the double arrow, there is a varying

Hauptanströmungsrichtung 2 in the sense of a cyclic change of

Direction of flow that drives the axial turbine 4 alternately in windward and in lee mode. Accordingly, the rotor blades 6.1, 6.2, which are fixed in a torsionally rigid manner to a rotor head 7 of the rotating unit 3 of the axial turbine 4, are designed as bidirectionally drivable rotor blades 6.1, 6.2. The necessary bidirectionally flowable profile, typically a double-symmetrical or S-shaped profile, extends at least over a partial region of the longitudinal extension of the sheet.

According to the invention, an additional turning device 13 is provided for a system designed for the combined windward and leeward operation, which allows a partial rotation of the machine nacelle 8. The rotation takes place about the plant vertical axis, which in the present case forms the axis of rotation 20. As shown, the interface between the rotating part 18 of the plant and the fixed part 27 is located on a tower adapter on the nacelle 8, which is at a

Coupling device 12 is placed on a support member 9. In this case, the support element 9 rests on a foundation part 10, through which the support on

River bottom 11 is effected.

FIG. 2 also outlines a flow measuring device 21 on the stationary part 27, which serves to detect the main flow direction 2. The

Measuring signals are transmitted to a control device 22, which for

Control and / or regulation of the rotary drive 23 for the rotary device 13 is provided.

Figure 1 shows the section A-A of Figure 2, wherein for clarity of the

Turning device 13 only the rotation angle limiting device is simplified outlined. Shown are a first stop 15 and a second stop 16 on the stationary part 27. These act with a projection 19 on the rotating part for limiting a rotation angle range 17 for the rotating device 13

together. For the present embodiment results for the nacelle 8, a rotation angle range 17 of 90 ° about the axis of rotation 20. By a in the

Individual rotary drive, not shown in Figure 1, a

Plant tracking within the rotation angle range 17 are performed.

The main flow direction 2 sketched in FIG. 1 shows a relative angle 14 to the axis of rotation 5 of the axial turbine 4 for a windward or leeward flow, which can be recirculated through the rotary device 13. Such variations of the main inflow direction 2 which may occur for tides at certain plant locations are shown in Figure 3 - illustrated is an asymmetric tidal ellipse. In this case, the main flow direction within a

Tidal phase due to site-specific conditions or due to weather conditions vary. This is shown in FIG

Main flow directions 2.1, 2.2, 2.3 for the flood phase and the

Main inflow directions 2.4, 2.5, 2.6 are shown for the ebb phase.

It can also be seen that the parts of the tidal ellipse associated with the ebb and the tide are not symmetrical, with one such

Flow characteristic of the present at the river bottom relief and the course of the coastline and the location upstream or downstream islands or marine engineering structures results.

In Figures 4a and 4b, the plant position for two different

Flowing situations shown. In Figure 4a, the present leads

Main flow direction 2.7 to a leeward operation of the system, as shown, the axis of rotation 5 and the main flow direction 2.7 are parallel. Figure 2.8 shows the power plant 1 in windward operation and in a by the

Turning device 13 tracked position. In this case, there is a relative angle 14 between the rotation axis 5 and the main flow direction 2.8. This is preferably on a time scale of a few minutes through the Rotary device 13 corrected, with a time averaging and filtering for the measurement data of the main flow direction 2.8 are based.

A simplified embodiment of the invention is outlined in FIGS. 5a, 5b. Shown is a power plant according to the invention in side view in two

different operating positions. In the present case, the rotating device 13 has a horizontally extending axis of rotation 20.2, which is a tilting movement of the

Machine nacelle 8 on the tower adapter, which forms the stationary part 27 allows. In Figure 5a, the nacelle 8 abuts a first stop 15.1 of the rotating device 13 and is in the operating position. Outlined is an alternating main flow direction 2, which leads to a bidirectional flow at the axial turbine 4 and to a combined windward and leeward operation.

By means of an overload detection device 24, which is in communication with the overload sensors 25.1, 25.2, the flow field is measured. In the case of one

Hauptanströmungsrichtung 2, the speed is above a predetermined threshold, is effected to relieve the axial turbine 4, a tilting movement of the machine nacelle 8 about the rotation axis 20 until reaching the second stopper 16.1. This operating position shown in Figure 5a leads to a

Oblique flow, which reduces the loads on the rotor blades 6.1, 6.2. The load reduction is based on a reduction of the projection area of the

Rotor circuit on a plane perpendicular to the main flow direction 2 level. Furthermore, the oblique flow leads to a change in the rotor characteristic which changes the power consumption and the rotor loads. The relative angle 14 between the rotation axis 5 and the main flow direction 2 set for this embodiment for system regulation by the rotary device 13 corresponds to the rotational angle range defined by the position of the first stop 15.1 and the second stop 16.1, which is less than 45 ° in the present case. To transfer the nacelle 8 from that shown in Figure 5a

Operating position to the illustrated in Figure 5b, regulated position, a buoyancy tank 26 in the nacelle 8 can be used. By blowing out the buoyancy tank 26 creates a positive buoyancy, the

Machine nacelle 8 rotates together with the axial turbine 4 in the partially raised position shown in Figure 5b. The righting moment must be sufficiently large that the back pressure of a leeward flow does not return the nacelle 8 to the first stop 15.1. Further embodiments of the invention will become apparent from the following claims.

LIST OF REFERENCE NUMBERS

power plant

.., 2.8 Main flow direction

3 revolving unit

4 axial turbine

5 rotation axis

6.1, 6.2 Rotor blade

7 rotor head

8 nacelle

9 support element

10 foundation part

11 body of water

12 coupling device

13 turning device

14 relative angle

15, 15.1 first stop

16, 16.1 second stop

17 rotation angle range

18 rotating part

19 advantage

20, 20.2 axis of rotation

21 flow measuring device

22 control device

23 rotary drive

24 Overload detection device

25.1, 25.2 Overload sensors

26 buoyancy tank

27 stationary part

28 tidal ellipse

Claims

claims

A power plant for generating energy from a stream of water having a varying main flow direction (2), comprising

1.1 a peripheral unit (3) with an axial turbine (4), the one

Is associated with rotation axis (5) and the at least one rotor blade (6.1, 6.2) comprises;

1.2 wherein the rotor blade (6.1, 6.2) rotationally fixed to a rotor head (7) of the

encircling unit (3) is attached; and

1.3 wherein the rotor blade (6.1, 6.2) for the windward and leeward operation at least over a portion of its longitudinal extent a bidirectional

having inflowable profile;

characterized in that

1.4 a rotating device (13) for a power plant component for adjusting a relative angle (14) between the rotation axis (5) and the

Main direction of flow (2) is present, wherein the rotary device (13) is associated with a first stop (15) and a second stop (16), the movement range of the rotating device (13) to a

Restrict rotation angle range (17) smaller than 180 °.

2. Power plant according to claim 1, characterized in that the revolving unit (3) is mounted on a nacelle (8), which of a

Support member (9) is supported, wherein the rotating device (13) between the nacelle (8) and the support element (9) is arranged.

3. Power plant according to claim 2, characterized in that the

Turning device (13) comprises a rotation axis (20.2) which extends horizontally and which is perpendicular to the axis of rotation (5) of the axial turbine (4). Power plant according to claim 2, characterized in that the rotary device (13) comprises a rotation axis (20) which extends vertically to the axis of rotation (5) of the axial turbine (4).

Power plant according to one of the preceding claims, characterized

characterized in that the axial turbine (4) is flowed around freely of the water flow and the rotating device (13) is arranged so that the position of the rotation axis (5) within the rotation angle range (17) is adjustable.

Power plant according to one of claims 1 - 4, characterized in that the axial turbine (4) is enclosed by a flow housing and the rotating device (13) is applied so that the position of at least one flow housing component is adjustable.

7. Power plant according to one of the preceding claims, characterized

in that the power plant comprises a flow measuring device (21) for determining the main flow direction (2), which is connected to a control device (22) for the rotary device (13).

8. Power plant according to one of the preceding claims, characterized

characterized in that the power plant comprises an overload detection device (24) which is connected to a control device (22) for the rotary device (13).

9. A method for operating a power plant for the production of energy from a stream of water with a varying main direction of flow (2) with a rotating unit (3) comprising an axial turbine (4), which is associated with a rotation axis (5) and the at least one rotor blade (6.1, 6.2), wherein the rotor blade (6.1, 6.2) rotationally fixed to the rotor head (7) of the rotating Unit (3) is attached; and

wherein the rotor blade (6.1, 6.2) for the windward and leeward operation over at least a portion of its longitudinal extension has a bi-directional inflow profile;

with the process step

a setting of a relative angle (14) between the rotation axis (5) and the main flow direction (2) by means of a rotating device (13), which are associated with a first stop (15) and a second stop (16), wherein the setting of the relative angle (14 ) is performed in a rotation angle range (17) which is limited by the first stop (15) and the second stop (16) to an angular range smaller than 180 °.