EP2870355A1

EP2870355A1 - Flow-based power generating plant with twist bearing in the blade root

Info

Publication number: EP2870355A1
Application number: EP13737188.6A
Authority: EP
Inventors: Martin Baldus; Efim GROH; Gerhard Jensen
Original assignee: Schottel GmbH
Current assignee: SCHOTTEL HYDRO GMBH
Priority date: 2012-07-06
Filing date: 2013-07-04
Publication date: 2015-05-13
Also published as: CA2877046A1; DE102012106099A1; WO2014006133A8; WO2014006133A1; US20150139804A1

Abstract

The invention relates to a flow-based power generating plant with a turbine that can be subjected to a fluid flow and comprises a number of blades that extend from a blade root to a blade tip and are attached by the blade root to a rotating rotor, wherein, under the effect of the fluid flow, the blades can be elastically twisted about an axis (P) running through the blade root in such a way that the pitch of the blades can be increased, wherein the blade root is fastened to the rotor with a bearing device interposed and the bearing device is formed with respect to the axis rigidly in terms of tension, compression, bending and shearing but yieldingly in terms of torsion, wherein the bearing device has a primary connection part fastened to the rotor and a secondary connection part fastened to the blade root, which parts are connected to one another via a multiplicity of leaf springs in such a way that the primary connection part can be turned in relation to the secondary connection part under elastic deformation of the leaf springs, and the leaf springs are arranged on a substantially circularly formed circumference and have a rectangular cross section with a longer side and a shorter side, the longer side running radially outwards with respect to the circumference on which the leaf springs are arranged.

Description

FLOW POWER PLANT WITH DRALL BEARING IN SHEET ROOT

Description:

The invention relates to a flow power plant with a turbine which can be started by a fluid flow and which comprises a plurality of wings extending from a flyfoot to a fuselage and attached to the rotor foot on a rotating rotor, the fins, under the influence of the fluid flow, passing around a finned foot Axis are elastically rotatable, such that the pitch of the wings is increased, the wing foot is fixed with the interposition of a bearing means on the rotor and the bearing means with respect to the axis tensile, compressive, bending and shear stiff, but torsionally soft ,

Flow power plants are known per se and may, for example, as wind or hydroelectric power plants from a corresponding fluid, i. Wind or water flow are impinged to generate electrical energy by rotation of the rotor within the turbine.

In such flow turbines, such as axially flowed tidal power plants or wind turbines, however, occur in addition to the desired torques also unwanted shear forces that must be derived with high construction costs through the structural components in the foundation. Particularly at high flow rates of the inflowing fluid, which exceed the nominal operating point, one endeavors to reduce the thrust To limit forces and also the absorbed power of the flow power plant by appropriate measures.

One type of thrust and power limitation is the so-called stall control. Here, the turbine is decelerated until it adjusts due to the Anströmsituation a flow tearing on the wings.

Another, now common, method is the so-called pitch control. In this case, the forces and moments that occur are limited, for example by with an adjustment mechanism, the vanes rotate to a higher pitch position, thus reducing the angle of attack, so as to reduce the energy taken from the fluid flow. Adjustment mechanisms for turbine blades are usually made of a bearing, which is designed as a rolling or sliding bearing and a drive that moves with an electric or hydraulic power supply, the wings in the desired position. A disadvantage of this design, in addition to the susceptibility to failure and the high construction cost of unavoidable wear on bearings and drive components, the regular maintenance is required, which, however, especially in poorly accessible offshore facilities are to be avoided.

From DE 30 17 886 A1 discloses a storage device is known which comprises a torsionally soft, as long as possible length having torsion bar and a hydraulic Anstelldämpfer. The device is difficult to interpret and is maintenance-intensive due to the stop damper.

It is known from GB 1 534 779 A to connect the vanes to the hub via a torsion spring which is clamped in bearing bushes at the end, this type of connection being flexible and also prone to wear in the area of the bearing bushes.

Object of the present invention is therefore to propose a flow power plant of the type mentioned, in which the wing adjustment as possible without wear and without separate supply of electrical or hydrau- iischer energy is based solely on the available fluid flow.

To achieve the object, a flow power plant according to the invention with the features of claim 1 is proposed.

Advantageous embodiments and modifications of the invention are the subject of the dependent claims.

In the context of the invention it is provided to fix the wings by means of the bearing means on the rotor, that from the fluid flow as a result of the flights! given geometry at this attacking normal and shear forces and bending moments with minimal deformation of the bearing device derived from the rotor and there converted into the desired rotation for generating geeelectric energy, whereas occurring torques about the axis of rotation of the wing, with the strength of the Correlate fluid flow, lead to the desired torsion of the wing about the axis of rotation and limit itself to the self-adjusting power of the same increasing the wing pitch.

An overload of the turbine, for example, in adverse weather conditions is thus automatically prevented, without the need for a control device and the supply of separate electrical or hydraulic energy to the flow power plant.

According to the invention, the bearing means comprises a primary fastener fixed to the runner and a secondary fastener fixed to the wing root, which are interconnected by a plurality of leaf springs, such that the primary fastener is rotatable relative to the secondary fastener under elastic deformation of the leaf springs. By suitable orientation and dimensioning of the leaf springs, it can then be achieved that the desired tensile, compressive, bending and shear stiffness is present between the primary terminal part and the secondary terminal part, but the desired torsional softness is present so that the primary terminal part is present and the Sekundäranschlussteii can rotate relative to each other and in the sequence of attached to the SekundÃ¤ranranschlussteii wings to increase its pitch is elastically rotatable when correspondingly strong fluid flow flows to.

The leaf springs are arranged according to the invention on a substantially circular circumference and have a rectangular cross-section with a longer and a shorter side, wherein the longer side extends radially outwardly relative to the circumference on which the leaf springs are arranged.

By this orientation, all leaf springs in the circumferential direction to a small moment of inertia and behave so torsionally soft, while they have a large area moment of inertia in the radial direction and in contrast to the allowable large torsional movements only small shear deformations, bending angles and longitudinal strains or - allow compression. A resulting due to the flow through the fluid elastic bending of the wing is thus divided in the storage device in tensile and compressive forces and derived almost no elastic deformation of the leaf springs in the rotor and the further structure of the flow power plant.

According to one proposal of the invention, it is provided that the leaf springs are formed coincident and have regular distances from each other to realize a uniform load-bearing behavior over the entire storage device.

According to one proposal of the invention, the primary terminal is connected to the secondary terminal by interposing the leaf springs, it being further possible for the leaf springs to have a straight axial extent, at one end the primary terminal and at the other, opposite end the secondary terminal is.

In addition to the arrangement of leaf springs along a circumference can also be provided that the primary terminal part and the Sekundäranschlussteii are concentrically aligned with each other and the leaf springs each comprise a plurality of part springs, which are arranged on concentrically arranged around each other and are connected to each other via an intermediate ring, wherein the one part springs are connected to the primary terminal part and the other part springs to the Sekundärranschiussteil.

Alternatively it can also be provided that the primary and the secondary secondary part are arranged concentrically to each other and the leaf springs have an approximately U-shaped configuration with two leg ends, of which one leg end is connected to the primary terminal part and the other leg end to the secondary terminal part. In such a case, for example, the Flügelfuß be hollow and engage in its inner cavity over the primary terminal part and the secondary terminal part protruding leaf springs.

In each of the aforementioned embodiments, however, the leaf springs used are each torque-rigid clamped in the primary end part and secondary end part.

Furthermore, it can be provided that end stops are present between the primary terminal part and the secondary terminal part, which limit the relative rotatability of the same to one another and to that extent define the starting and ending point of a working area of the storage device according to the invention. This makes it possible, for example, to limit the maximum elastic rotation of the wing and thus the maximum increase in wing pitch by the end stop is approached, which defines the end point of the working area.

Furthermore, it can also be provided that the leaf springs are already elastically biased at the starting point of the work area, so that an exceeding rotation of the wings using their slope increases only after overcoming the set by the bias elastic restoring forces of the leaf springs. In that regard, it is possible by appropriate dimensioning of the leaf springs used and the bias of the same a wing adjustment in terms of an increase in the slope of the same can only be used when the flow power plant inflowing fluid flow exceeds a suitably predeterminable threshold, while falls below this threshold no significant increase in the wing pitch, so that the flow power plant according to the invention until reaching a predetermined nominal operating point can work with maximum energy yield from the fluid flow through optimized sash position.

According to a proposal of the invention, the leaf springs are preferably made of anisotropic materials, which may include, for example, suitable metals, such as corresponding spring steels, but also suitable fiber composites.

Further embodiments and details of the invention will be explained in more detail with reference to the embodiments illustrative drawings. Show it:

Fig. 1 is a front view of a flow power plant according to the invention

2 shows the side view of the flow power plant according to FIG. 1

Fig. 3 shows the view of the rotor of the flow power plant according to Figure 1 in an enlarged view

4a shows a first embodiment of a storage device according to the invention in a perspective view

Fig. 4b, the storage device according to Figure 4a in side view

Fig. 4c, the storage device according to Figure 4a in plan view

Fig. 5a shows a wing of the flow power plant according to the invention in

undeformed condition Fig. 5b of the wing of Figure 5a in a deformed state

Fig. 6a, the top view of the storage device of the wing according to FIG

5a

Fig. 6b, the top view of the storage device of the wing according to FIG

5b shows a detail of the storage device according to FIG. 6a

Fig. 8 shows a further embodiment of a storage device according to the invention Fig. 9 shows a further embodiment of a storage device according to the invention

FIGS. 1 and 2 show a flow power plant 1 which, for example, can be flowed by a flow of water as a tidal power plant or by an air flow as a wind power plant. The flow power plant 1 comprises starting from a foundation 14 a vertically extending mast 13, at the upper end of a turbine 12 is arranged with a rotor 10, which can be set in known manner by the streamed by the wing 1 wings in rotation and a in the interior of the turbine 12 arranged generator for generating electrical energy can drive.

As can also be seen in particular from FIG. 3, the respective wing foot 110 of the wing 11 extending up to a wing tip 111 is fastened to the rotor 10 via a bearing device designated by reference numeral 15 in order to achieve the desired energy conversion from the fluid flow into the rotation of the rotor 10 cause. In this case, the bearing devices 15 comprise a primary clamping part 150 designed as a round disk and fastened to the rotor 10, and a secondary disk section 152 likewise designed as a round disk and fastened to the blade leg 110, which are held apart from one another by a multiplicity of leaf springs 151 described in more detail below and connected with each other.

As can be seen in particular from the combination of FIGS. 4a to 4c, the leaf springs 151 are all made coincident and arranged at regular intervals from one another along a circular circumference, wherein they are anchored to one of their ends in the primary connecting part 150 or secondary connecting part 152 in a torque-stable manner ,

The individual leaf springs 151 act as bending rods and are designed for this purpose with a rectangular cross-section, with a short side 1510 and the opposite side significantly longer, here about four to five times longer side 5 and oriented so that the longer side 511 based on the circumference on which the leaf springs 151 are arranged extends radially outward.

Infoige this orientation of the leaf springs 151, which may be made for example of a suitable anisotropic material, such as spring steel or suitable fiber composites, is achieved that these attacking forces, such as those in Figure 4b with K1 and K2 forces, large area moment of inertia and correspondingly high Oppose resistance, but oppose moments occurring according to arrow M about the vertical axis only extremely low moment of inertia and accordingly give the bearing means 15 a characteristic that this tensile, compressive, bending and shear stiff, but torsionally soft.

By using such a storage device 15 in the connecting region between the blade root 10 of the wing 11 and driven by this rotating rotor 10 ensures that the wings 11 under the action of Fluid flow around an example of Figure 1 apparent, passing through the blade root 110 axis P are elastically rotated, such that with increasing fluid flow, the pitch of the wings is increased in order to limit the power consumption thereof.

This becomes clear from a comparative examination of the representations of FIGS. 5a, 5b and, corresponding thereto, 6a, 6b.

From FIG. 5a, and correspondingly to the enlarged illustration of the bearing device 15 according to FIG. 6a, a wing 11 can be seen, which is flown by a weak or no fluid flow H. The resulting from this at best weak flow of the wing profile of the wing 11 due to the flow H resulting normal forces N, associated transverse forces Q, Torsionsmomente T and any bending moments B on the wing 11 generate forces by the forces K1, K2 in the illustration of Figure 4b are represented and due to the characteristic train, pressure, bending and shear stiff design of the storage device 15 of this without significant deformation starting from the secondary terminal part 152 via the leaf springs 151 and the primary shear part 150 in the rotor 10 (not shown here) are initiated. It can be seen on the basis of the enlarged illustration according to FIG. 6a that the leaf springs 151 do not undergo appreciable deformation here, since they counteract these occurring forces by their large area moments of inertia due to their characteristic orientation as explained above.

But if the fluid flow increases, this flow generates according to arrow H in addition to those already explained with reference to FIG 5a forces and moments T of Figure 5b, where the storage device 15 due to their torsionally soft training is unable to set a sufficiently large moment of resistance conditions and insofar can be relatively easily deformed in response to these attacking large torsional moments T the leaf springs 151, as shown in particular in the representation of Figure 6b, so that there is a relative rotation between the primary end portion 50 and the secondary end portion 152 about the axis P of Figure 1 , Subsequently increases the slope of the so twisted about its axis P wing 11, so that the correlated thereby power consumption from the fluid flow H is reduced, since the angle of attack is correspondingly larger. This rotation of the blade 11 is elastic, since the leaf springs 151 generate a corresponding restoring moment and as far as the wing 1 is also turned back to its original or initial position according to FIG 5a, as soon as the fluid flow H decreases sufficiently.

In other words, large forces N, transverse forces Q, bending moments B and torsional moments T occur under great load due to strong fluid flow H. However, as a result of these large forces, only significant rotation of the bearing device 15 in the direction of torsional moment T occurs.

Thus, the desired automatic and without additional energy supply exiting adjustment of the wings to limit the power consumption of the flow power plant and to protect the same from overload realized.

Of course, as clearly visible in Figure 2, the longitudinal axis of the bearing of the wings 11 have an axial angle less than 90 ° to the main axis of rotation of the rotor 10 to produce in combination with the center of gravity of the wing outside the bearing longitudinal axis resulting from the centrifugal torque which favors the above-described twisting or torsion in the region of the bearing device 15.

Likewise, the longitudinal axis of the bearing may be deviated from the profile-generating axis of the wing in order to generate a torque generated from the hydrodynamic loads, which also supports the desired wing twisting.

In a further development of the invention, it is provided that 152 end stops are provided between the primary terminal part 150 and the secondary terminal part, which limit the relative rotatability thereof to each other. For this purpose, it can be provided, for example, as can be seen from FIG. 7, to provide elongated holes 155 in the secondary connecting part 152, in which a bolt 54, which is firmly clamped in the primary clamping part, not shown here, is guided. The respective end regions of the elongated holes 155 then define the end stops 156 and 157, which at the same time define the start and end points of a working region A of the bearing device 15. In the embodiment shown in Figure 7, the end stop 156 defines the starting point of the working area A and the end stop 157 the end point of the working area A. Once the end stop 157 is reached, this limits further rotation of the wing towards even greater wing pitch, so that the with the storage device according to the invention enabled elastic rotation of the wings 11 is limited. In addition, an embodiment according to FIG. 7 also permits a predeterminable prestressing of the leaf springs 152 if the starting point of the working area A defined by the first end stop 156 does not coincide with the relaxed position of the leaf springs 151 as shown in FIG. 6 a the bolt 154 should actually be in the indicated position according to reference numeral 153. In the Ausführungsbeispiei shown here, the bolt 154 is already rotated in the direction of rotation at the starting point of the work area by the angle V, in which the wing is to be rotated due to the attacking flow H, ie the leaf springs 151 are biased accordingly and act on the Primäranschluss- part 150 and the secondary terminal part 152 with corresponding restoring forces. However, the complete relaxation of the leaf springs 151 is prevented by the end stop 156 against which the pin 154 rests.

The size of this biasing force of the leaf springs can be easily adjusted by determining the angle V of the respective conditions.

With such a preloaded bearing device 15, torques 11 acting on the wing 11 only lead to a further rotation of the same in the direction of an increased pitch, if these moments due to the bias voltage V caused Rückstelikräfte the leaf springs 151 exceed. Thus, it is possible to define a predeterminable and dependent on the restoring forces of the leaf springs 151 threshold to which the wings 1 experience no rotation generated by the fluid flow and thus take optimal with optimal Figeigeometrie the fluid flow energy and only when this threshold is exceeded then sets the To limit the power desired adjustment of the wings 11 in the direction of an increased pitch to prevent mechanical damage and overloading. Such a working flow power plant is characterized by maximum efficiency.

Instead of the apparent in particular from the figures 4a to 4c embodiment of a bearing element 5 with radially outwardly facing and arranged on a circumference leaf springs 151 also Ausgestaitun- gene in the context of the invention are possible.

Thus, FIG. 8 shows a bearing element 15, in which each leaf spring 151 is formed in each case by two part springs 151a, 151b arranged one behind the other in the radial direction. Through an intermediate ring 153, which connects the part springs 151a, 51, a series connection of the part springs 151a, 151b is achieved, which results in a reduced torsional strength.

In the embodiment shown here, the part springs 5 a, 151 b and the primary terminal part 150 and the secondary terminal part 152 are arranged concentrically to each other in order to realize the reduced torsional strength in a comparatively small space. In this case, the blade root 1 0 is formed as shown by dashed lines, hollow and receives the over the primary terminal part 150 and the secondary terminal part 152 vertically projecting leaf springs 151 in its cavity and is suitably connected to the secondary terminal part 152.

FIG. 9 shows a further possible embodiment of a bearing device 15, in which the primary connection part 150 and the secondary connection part 152 are not under the interposition of the leaf springs 151 of each other but they are arranged concentrically with each other, ie, the primary terminal part 150 as a circular disc and surrounded by the annular concentric thereto arranged Sekundäranschlussteil 152. The leaf springs 151 in this case have an inverted U ~ shaped shape and have two leg ends 151.1 and 151.2, of which one leg 151.1 acts on the primary connecting part 150 and the other leg 151.2 on the secondary connecting part 152. Also in this case, the blade root 110 is formed as shown by dashed lines, hollow and receives the over the Primanzranschiussteil 150 and the Sekundaulranschlussteil 152 vertically protruding leaf springs 151 in its cavity and is suitably connected to the secondary secondary part 152.

It is understood that depending on the application even deviating arrangements of the leaf springs 151 between the primary terminal part 150 and the secondary terminal part 52 can be made.

With the above-described flow power plant, it is possible to store the wings wear-free elastic and to adjust within its operating range. The energy required for staging is taken without supply of electrical or hydraulic energy solely from the hydrodynamic thrust forces and / or from the centrifugal forces of the blades, so that this hitherto undesirable but unavoidable forces have a meaningful function.

Claims

1. Ström ungskraftwerk (1) with one of a fluid flow (H) inflatable turbine, which several of a wing foot (1 10) to a wing tip (1 1 1) extending and with the Flugungsfuß (110) on a rotating rotor ( 10) fixed wings (11), wherein the wings (1 1) under the influence of the fluid flow (H) about an axis by the Flügelfuß (110) duri fig fering fenden axis (P), such that the pitch of the wings ( 1 1) is enlargeable, wherein the wing base (1 11) with the interposition of a bearing device (15) on the rotor (10) is fixed and the bearing device (15) with respect to the axis (P) tensile, pressure, bending and shear stiff, but torsionally soft, characterized in that the bearing means (15) comprises a rotor (10) attached to the primary fastener part (150) and the wing base (110) attached to the secondary terminal part (152), which over a plurality of Blattfe in that the primary terminal (150) is rotatable relative to the secondary terminal part (152) under elastic deformation of the leaf springs (151), and the leaf springs (151) are arranged on a substantially circular periphery and a rectangular one Cross-section having a longer and a shorter side (151 1, 1510), wherein the longer side (15 1) relative to the circumference, on which the leaf springs (151) are arranged, extends radially outwardly.

Second flow power plant (1) according to claim 1, characterized in that the leaf springs (151) are formed coincident and have regular distances from each other.

3. flow power plant (1) according to any one of claims 1 or 2, characterized in that the Primäranschlussteii (150) with the interposition of the leaf springs (151) with the secondary terminal part (152) is connected.

4. flow power plant (1) according to claim 3, characterized in that the primary terminal part (150) and the secondary terminal part (152) are concentrically aligned with each other and the leaf springs (151) each comprise a plurality of part springs (151a, 151b) arranged on concentric to each other Scopes are arranged and over an intermediate ring

(153) are connected to each other, wherein the part springs (151 a) with the primary terminal part (150) and the part springs (151 b) are connected to the secondary terminal part (152).

5. flow power plant (1) according to one of claims 1 to 3, characterized in that the primary end part (150) and the secondary end part (152) are arranged concentrically to each other and the leaf springs (151) has an approximately U-shaped configuration with leg ends (151.1, 151.2), of which one leg end (151.1) is connected to the primary connecting part (150) and the other leg end (151.2) is connected to the secondary connecting shaft (152).

6. flow power plant (1) according to one of claims 1 to 5, characterized in that end stops (156, 157) are provided between the primary end part (150) and the secondary kundärranschlussteil (152), the relative rotation of the same limit each other and define the beginning and end point of a work area (A) of the storage device (15).

7. flow power plant (1) according to claim 6, characterized in that at the starting point of the working area (A), the leaf springs (51) are resiliently biased.

8. flow power plant (1) according to one of claims 1 to 7, character- ized in that the leaf springs (151) are made of anisotropic materials.