Turbine device Description Prior art The invention relates to a turbine device according to the preamble of Claim 1, to a hydropower plant according to Claim 12 having a corresponding turbine device and to a method for designing a hydropower plant according to Claim 13.
The publication EP 2 295 808 A2 discloses a turbine device having stator vanes which are inclined at a flat angle in order to avoid injury of fishes.
Further, a turbine device according to the preamble of Claim 1 is known from the publication US 2018/106234 Al.
The object of the invention consists in particular in providing a generic device with improved characteristics in terms of safety, in particular a fish-friendliness, in par- ticular while at least largely maintaining efficiency.
The object according to the invention is achieved through the features of Patent Claims 1 and 13, while advan- tageous configurations and further developments of the invention can be taken from the subclaims.
Advantages of the invention
The invention is based on a turbine device, in particular a Kaplan turbine device, tubular turbine device and/or Straflo turbine device, with at least one conduction unit for conducting at least one fluid flow and with at least one impeller vane unit which is arranged within the conduction unit, which is rotatable around a rotation axis and which comprises at least one impeller vane, and with a protective unit which is configured in at least one operating state to urge objects flowing in the fluid flow in particular flotsam and preferably fishes, in particular eels in the direc- tion towards the rotation axis.
By way of this, damage to the objects through sharp
< 9 - outside edges of the impeller vane can be avoided.
Advantageously, a safe and/or fish-friendly configuration of the impeller vane can be concentrated on a sub-region of the impeller vane which is nearest to the rotation axis.
A ”turbine device” is to mean in particular a device which is provided to convert kinetic energy of a fluid, in particular water, into rotational energy, in particular of a shaft of the turbine device.
Preferentially, the kinetic energy is created through a conversion of a potential energy of the fluid.
Advantageously, a flow direction of the fluid flow runs at least partially along a gravity direction.
In particular, the conduction unit defines the flow direction of the fluid flow.
A “conduction unit” is to mean in particular a unit which is provided for conducting the fluid flow.
Preferably, the conduction unit comprises at least one in particular tubular conduction element.
Preferably, the conduction unit comprises at least one inlet and one outlet, between which the impeller vane unit is arranged.
In particular, a flow direction of the fluid flow can vary continuously and/or abruptly between the inlet and the outlet.
An “impeller vane unit” is to mean in particular a unit which is provided to be subjected in the operating state to a rotational movement caused by a passing fluid flow.
Preferably, the impeller vane unit is operatively connected to at least one generator unit of the turbine device, which converts rotational energy of the impel- ler vane unit into electric energy.
In particular, the turbine device comprises at least one shaft which defines the rotation axis.
Advantageously, the impeller vane unit comprises at least one impeller vane hub attached to the shaft.
The impeller vane hub carries in particular the impeller vane.
In particular, the impeller vane can be rotatable relative to the impeller vane hub.
Alternatively, the impeller vane could also be firmly connected to the impeller vane hub.
Preferentially, the impeller vane comprises at least one mounting element, which makes possible a mounting of the impeller vane to the impeller vane hub and/or defines an adjusting rotary axis of the impeller vane relative to the impeller vane hub.
Alternatively and/or addition- ally, the impeller vane unit can comprise at least one vane ring which surrounds in
< 3 -
particular when viewed along the rotation axis, all impeller vanes of the impeller vane unit.
In particular, the vane ring lies against outer edges of all impeller vanes.
The impeller vane comprises in particular at least one vane leaf which preferentially comprises in particular leaf regions located in particular with respect to the adjust- ing rotary axis opposite one another.
In this context a “leaf region” is to mean in particular a part of the vane leaf that is distinct from a pure surface which comprises at least 20%, advantageously at least 30% and preferably at least 40% of a volume of the vane leaf.
In particular, both leaf regions can form the entire vane leaf.
Ad-
vantageously, the first leaf region forms a front side of the impeller vane and the second leaf region a back of the impeller vane.
A “front side” in this context is to mean in particular a part of the vane leaf which is arranged nearer the inlet of the conduction unit than a back.
Advantageously, the vane leaf comprises two main surfaces located opposite one another, which are preferentially jointly defined by both leaf regions.
In this context, a “main surface of the impeller vane” is to mean in particular a surface which defines a side of the vane leaf.
Preferentially, the im-
peller vane comprises at least two main surfaces located opposite one another.
It would be conceivable that both leaf regions are formed so as to be axially symmet-
rical to one another in particular axially symmetrical to the adjusting rotary axis.
In particular, the vane leaf comprises at least one outer edge which preferably de- fines a joint outer edge of both leaf regions.
In particular, the front side comprises at least one front edge located opposite the outer edge.
In particular, the back com-
prises at least one rear edge located opposite the outer edge.
The outer edge can be formed in particular as a continuous edge.
Alternatively, the outer edge could be interrupted by at least one stabilizing element of the impeller vane.
A “stabilizing element” in this context is to mean in particular a part of the impeller vane which is provided, in an operating state, to stabilize the impeller vane preferentially dur-
ing rotation of the impeller vane.
Particularly preferably, the stabilizing element is formed integrally with the vane leaf.
In particular, the leaf regions, the mounting element and the stabilization element are formed integrally with one another. “In- tegrally” is to mean in particular to be connected in particular in an integral manner,
for example through a welding process, a bonding process, an over-moulding pro-
cess and/or another process deemed practical to a person skilled in the art and/or
< 4 - advantageously formed in one piece, such as for example through manufacture from a single mould and/or through manufacture in a one-component or multi-compo- nent injection moulding method and advantageously from a single blank.
Preferentially, the turbine device is configured as a Kaplan turbine device.
A “Kaplan turbine device” is to mean in particular a turbine device in which the flow direction of fluid striking the impeller vane runs at least approximately parallel to the rotation axis.
Here, “at least approximately” is to mean in particular that the flow direction and the rotation axis jointly define an angle of maximally 40%, ad-
vantageously maximally 35%, advantageously maximally 30% and particularly ad- vantageously maximally 25%. Preferably, the impeller vane of the Kaplan turbine device 1s configured so as to be adjustable.
The objects can preferentially comprise objects naturally occurring within bodies of water, such as for example water plants and/or aguatic creatures, in particular fishes, in particular, eels and/or crabs and/or mussels.
It would also be conceivable that the objects comprise foodstuff and/or land-based plants and/or land-based crea- tures.
An object being “urged” in a direction is to mean in this context in particular that a movement against the direction is rendered more difficult for the object and/or a movement along the direction is rendered more favourable to the object and/or the object is transported in the direction.
Preferably, the protective unit is free of sharp edges at least in a region accessible to the objects.
Advantageously, the protective unit is free of impact surfaces which run perpendicularly to a move- ment direction of the objects.
Particularly advantageously, the protective unit causes a continuous movement of the objects in the direction to the rotation axis.
It would be conceivable that the protective unit is at least partially detachably mounted to a remaining turbine device.
Furthermore, it is proposed that the protective unit is provided to conduct the flow-
ing objects radially towards the rotation axis.
Preferably, the protective unit con- ducts the flowing objects, by means of a shaping of the protective unit, radially towards the rotation axis.
In particular, the protective unit comprises sub-regions which upon contact of the flowing objects with the sub-regions, causes the objects
< 5 - to slide off radially towards the rotation axis.
Advantageously, the protective unit comprises at least one deflection element which is provided to redirect a movement direction of the objects.
In particular, the deflection element is formed as a me- chanical element.
It would be conceivable that the deflection element is configured as a rail which is configured in particular so as to be separate from the impeller vane unit and steers the flowing objects radially towards the rotation axis prior to a contact with the impeller vane unit.
Thus, in particular a careful and easily im- plemented movement of the flowing objects radially towards the rotation axis can be achieved.
Advantageously, damage to the flowing objects through the movement of the flowing objects radially to the rotation axis can be avoided.
Particularly pref- erably, the movement of the flowing objects radially towards the rotation axis can be achieved without any additional energy consumption to speak of and/or any sig- nificant deterioration of an efficiency of the turbine device.
The protective unit is formed at least partially integrally with the impeller vane unit.
That two units are configured “at least partly integrally” with one another is to mean in this context in particular that the two units comprise at least one common element.
Preferably, the protective unit is configured at least partially integrally with the impeller vane.
Thus, an in particular compact and sturdy design of the protective unit can be achieved.
Advantageously, installation space can be saved compared with a separately configured protective unit.
Particularly advanta- geously, a detaching and/or displacing of the protective unit during an operation of the turbine device can be avoided.
The protective unit comprises at least one contour element of the impeller vane.
A “contour element” is to mean in particular an element of an object which, along a predefined viewing direction looking at the object, partially defines an outer con- tour of the object.
Preferably, the predefined viewing direction onto the contour element is perpendicularly to a main surface of the impeller vane.
That the contour element looking along the viewing direction, “at least partially defines” the outer contour of the object in this context is to mean in particular that the contour ele- ment, looking along the viewing direction, defines the outer contour of the object at least by 10%, advantageously at least by 20% and particularly advantageously by at least 30%. An “edge” is to mean in particular a surface region of the impeller vane which connects the main surfaces of the vane leaf.
For example, the edge could be configured smooth or rounded.
Thus, a protection of the flowing objects can be improved in particular.
Advantageously, damage to the flowing objects by the impeller vane can be avoided.
In order to augment the protection of the flowing objects even further, the contour element forms at least partly, advantageously for a major part and preferably com- pletely, a front edge of the impeller vane.
Thus, a careful configuration of the front edge which in the prior art is particularly dangerous to flowing objects, can be achieved.
Advantageously, a cutting into pieces of the objects because of a rota- tional movement of the front edge can be avoided.
Further it is proposed that the front edge is at least substantially realized in a sickle shape. “At least substantially” is to mean in particular that a difference is within popular manufacturing tolerances.
That the front edge of the impeller vane is to be realized “in a sickle shape” is to mean in this context in particular that the front edge has a curvature and at least one end of the edge meets a further end of a further edge in particular the outer edge, of the impeller vane with a further curvature and contributes to the forming of a tip.
A “curvature” in this context is to mean in par- ticular a local change of a course direction, in particular during a movement from the first end of the front edge to the second end of the front edge.
An *end” in this context is to mean in particular a part region of the front edge, which delimits the front edge along a course direction of the front edge towards the outside and the length of which amounts to maximally 20%, advantageously maximally 15%, pref- erably maximally 10% and particularly preferably maximally 5% of a length of the front edge.
A “tip” is to mean in particular a sub-region of a body which delimits the body in at least one direction towards the outside and has a shape tapering along the direction.
Preferably, the tip is oriented facing away from the rotation axis.
In particular, a leaf region comprising the front edge is realized in a sickle shape.
Advantageously, the front edge, at least with a perpendicular view onto at least one main surface of the impeller vane, is configured arc-shaped. “Perpendicular view onto a surface” is to mean in particular a viewing direction which, with a point of
< 7 - the surface it intersects, defines a right angle.
In particular, the perpendicular view onto the surface can be dependent on a viewed point of the surface.
An *arc-shaped front edge” in this context is to mean in particular an edge which has a curvature extending over the entire edge and which is preferentially continuously variable.
Preferentially, the front edge is curved towards the rotation axis.
Thus, a conducting of the flowing objects towards the rotation axis can be improved in particular.
Ad- vantageously, projections and/or protruding tips and/or corners of the front edge, which could damage the flowing objects, can be avoided.
Furthermore it is proposed that the front edge in at least one operative position of the impeller vane unit penetrates a plane extending perpendicularly to the rotation axis in at least one intersection point, which during an imaginary movement of the plane parallel to the rotation axis, is displaced in a radially non-uniform manner.
In particular, the imaginary movement of the plane describes at least substantially a movement of the flowing objects.
Advantageously, the intersection point is dis- placed upon a constant movement speed of the plane with, in particular continu- ously, an increasing movement speed.
Thus, a gentle conducting of the flowing objects to the rotation axis can be achieved in particular.
Advantageously, a con- ducting of the flowing objects to the rotation axis can be ensured before the flowing objects pass the front part.
Particularly advantageously, damaging the flowing ob- jects by too abrupt a conducting of the flowing objects can be avoided.
In order to increase an efficiency it is proposed that with a view perpendicularly onto a main surface of the impeller vane and an imaginary movement of a point from an end of the front edge to a further end of the front edge, a movement direc- tion of the point rotates by at least 70°, in particular at least 120°, advantageously at least 170°, preferably at least 220° and particularly preferably at least 270° in a direction.
In particular, a first end of the front edge is substantially oriented per- pendicularly to the rotation axis.
Preferentially, a second end of the front edge con-
tributes to the forming of the tip.
Thus, objects flowing in particular through a sin- gle impeller vane can be intercepted over a wide range and urged in the direction towards the rotation axis.
In particular, a maximum perpendicular distance when viewed perpendicularly be- tween a connecting line of two end points of the front edge and any remaining points of the front edge amounts to at least 15%, advantageously at least 25%, pref- erably at least 35% and particularly preferably at least 45% of a length of the con- necting line.
Advantageously, the distance defines a local movement speed of the intersection point to the rotation axis.
Thus, a safety can be increased in particular in an efficient manner.
Advantageously, a material-saving and light impeller vane with increased safety, in particular increased fish-friendliness, can be provided.
Advantageously, the front edge has a rounding which connects at least one first main surface of the impeller vane with at least one second main surface of the impeller vane located opposite.
In particular, the rounding forms a concave sub- region of the impeller vane.
Advantageously, when viewing a cross-sectional con- tour of the rounding perpendicularly to the main surfaces, a maximum perpendicu- lar distance between a connecting line of two end points of the rounding and any remaining points of the rounding amounts to maximally 40%, advantageously max- imally 35%, preferably maximally 30% and particularly preferably maximally 25% of a length of the connecting line.
Preferentially, the perpendicular distance de- creases radially in the direction of the rotation axis.
Thus, damage to the flowing objects in particular during the conduction can be avoided even better.
Advanta- geously, a severing of the flowing objects by the front edge can be avoided.
According to the invention, a thickness of the front edge increases radially in the direction of the rotation axis, preferentially continuously.
Advantageously, the rounding of the front edge flattens out proportionally to a thickness of the front edge.
Preferably, the front edge is aligned with the mounting element.
In particular damage to the flowing objects near the rotation axis can thus be easily avoided.
Advantageously, impact forces upon an impact of the flowing objects on an end region of the front edge facing the rotation axis can be distributed over a higher area.
Preferably, the thickness radially in the direction of the rotation axis increases by at least 200%, advantageously at least 400%, preferably at least 600% and particularly preferably at least 800%. Thus, in particular a damage of the flowing objects near the rotation axis can be avoided even better.
Advantageously, the rounding of the front edge can be configured sufficiently flat in order to prevent a severing of the flowing objects by the front edge.
In order to efficiently increase a fish-friendliness it is proposed that the impeller vane is configured rotationally non-symmetrically.
That a body is *rotationally non-symmetrical” is to mean in particular that the body, with respect to any rotation axes, is free of rotational symmetries.
In particular, both leaf regions are free of rotational symmetries relative to one another.
Advantageously, the second leaf re- glon comprises, with a view perpendicularly onto the main surface of the impeller vane, a substantially linearly extending rear edge.
Advantageously, a configuration of a rear edge, which does not touch the flowing objects anyway, can be dispensed with with increased safety.
Particularly advantageously, the further leaf region comprising the rear edge can be configured instead for an optimal energy genera- tion.
In addition to this it is proposed that the protective unit comprises at least one shielding element which is provided to at least render an entering of objects in a region between a radially outer side of the impeller vane and at least one wall of the conduction unit more difficult.
In particular, the shielding element can be pro- vided, with a view along the rotation axis, to cover a region between a radially outer side of the impeller vane and at least one wall of the conduction unit.
That the shielding element “covers” the region is to mean in particular that the shielding element renders a movement of the flowing objects into the region more difficult and preferentially avoids such.
A *radially outer side” is to mean in particular a side of the impeller vane which faces away from the rotation axis.
In particular, the outer edge of the impeller vane defines the radially outer side of the impeller vane.
In particular, the vane ring could contribute to rendering the entry of the objects into the region between the radially outer side and the wall more difficult.
Thus, in particular a safety of the outer edge can be increased.
Advantageously, damaging the flowing objects by the outer edge can be avoided.
= 10 - In an alternative configuration, the shielding element could be configured as a sep- arate additional element attached to the conduction unit.
Preferably, the shielding element is at least partially formed integrally with the conduction unit and prefer- entially configured as a set-back portion of the conduction unit.
In particular, the shielding element connects a first sub-region of the conduction unit facing the inlet with the wall, which in particular is a part of a second sub-region of the conduction unit facing the outlet.
In particular, the wall and/or the second sub-region can, rel- ative to a first diameter of the first sub-region, a higher and/or substantially identi- cal diameter.
That a value and/or an element is “at least substantially identical” to a further value and/or element is to mean in particular that the value and/or the element has a deviation of maximally 20%, advantageously maximally 15%, pref- erably maximally 10% and particularly preferably maximally 5% with respect to the value and/or a shaping of the further element.
In particular, the wall can follow a straight and/or curved course.
Thus, a safety of the outer edge can be increased in particular in a simple manner.
Advantageously, additional mounting steps for attaching the shielding element can be dispensed with.
Further, a hydropower plant, in particular with augmented protection of objects flowing in a fluid flow, with a turbine device according to the invention, is pro- posed.
Thus, a safety of objects flowing through the hydropower plant, in particular flotsam and preferably fishes, in particular eels, can be increased in particular.
The invention is based on a further aspect of a method for designing a hydropower plant, in particular with augmented protection of objects flowing in a fluid flow.
It is proposed that a reduction of efficiency because of a use of a turbine device according to the invention is at least compensated by dispensing with at least one further protective measure for objects flowing in the fluid flow.
The protective measures comprise for example a use of flotsam rakes and/or a reduction of a bar spacing of flotsam rakes.
Thus, an efficiency of the hydropower plant with a high safety of the hydropower plant can be increased in particular.
The turbine device according to the invention shall not be restricted to the applica- tion and embodiment described above. In particular, for fulfilling a function de- scribed herein, the turbine device according to the invention can comprise a number of individual elements, components and units deviating from a number mentioned herein. Drawings Further advantages are obtained from the following drawing descriptions. In the drawings, two exemplary embodiments of the invention are shown. The drawings, the description and the claims contain numerous features in combination. Practi- cally, a person skilled in the art will also consider the features individually, and combine these into practical further combinations. There:
Fig. 1 shows a schematic representation of a hydropower plant with a turbine de- vice,
Fig. 2 shows a more detailed schematic representation of a part of the turbine device,
Fig. 3 shows different schematic views of an impeller vane of the turbine device,
Fig. 4 shows a schematic flow diagram of a method for designing the hydropower plant,
Fig. 5 shows a more detailed schematic representation of a part of a further tur- bine device, and
Fig. 6 shows different schematic views of a further impeller vane of the further turbine device. Description of the exemplary embodiments
= 12 -
Fig. 1 shows a hydropower plant 44a. The hydropower plant 44a has an augmented protection of objects (not shown) flowing in a fluid flow (not shown). The hydro- power plant 44a comprises a dam 46a. The hydropower plant 44 comprises a power house 48a. The hydropower plant 44a comprises a turbine device 10a. A part of the turbine device 10a is shown in more detail in Figure 2. The turbine device 10a is configured as a Kaplan turbine device. Alternatively, the turbine device 10a could also be con- figured as a tubular turbine device and/or a Straflo turbine device. The turbine device 10a comprises a conduction unit 12a. The conduction unit 12a is provided for conducting the fluid flow. The conduction unit 12a is configured as a tubular system. The conduction unit 12a comprises an inlet opening 50a. The conduction unit 12a comprises an outlet opening 52a. The inlet opening 50a and the outlet opening 52a jointly define a direction of the fluid flow. The fluid flow runs from the inlet opening 50a to the outlet opening 52a. The turbine device 10a comprises an impeller vane unit 16a. The impeller vane unit 16a is arranged within the conduction unit 12a. The impeller vane unit 16a is rotatable about a rotation axis 14a. The rotation axis 14a is oriented parallel to a gravity direction. Alterna- tively, the rotation axis 14a could also be oriented perpendicularly to a gravity di- rection. The impeller vane unit 16a comprises an impeller vane hub 58a. The im- peller vane hub 16a comprises four impeller vanes, which are configured identically to one another, which merely one impeller vane 18a is given a reference sign and is described in the following. Alternatively, the impeller vane unit 16a could also comprise any other numbers of impeller vanes. The impeller vane 18a is rotatably connected to the impeller vane hub 58a. The impeller vane 18a is in an operative position. The impeller vane unit 16a comprises a vane ring 80a. The vane ring 80a, with a view along the rotation axis 14a, surrounds the impeller vane 18a. The vane ring 80a comprises recesses. The impeller vane 18a comprises a stabilizing element 72a. The stabilizing element 72a is provided to stabilize the impeller vane 18a during a
= 13 - rotation of the impeller vane 18a. The stabilization element 72a engages into one of the recesses of the vane ring 80a. The impeller vane unit 16a is firmly attached to a shaft 54a. The shaft 54a is oper- atively connected to a generator 56a. The generator 56a is arranged in the power house 48a. In an operating state, the fluid flow rotates the impeller vane unit 16a. The impeller vane unit 16a passes the rotation on to the shaft 54a. Using the rotation of the shaft 54a, the generator 56a generates power. The turbine device 10a comprises a protective unit 20a. The protective unit 20a is provided to urge, in the operating state, objects flowing in the fluid flow in the direction in the direction towards the rotation axis 14a. The protective unit 20a is provided to conduct the flowing objects radially towards the rotation axis 14a. Al- ternatively, the protective unit 20a could also merely prevent a movement of objects flowing near the rotation axis 14a against the rotation axis 14a. The protective unit 20a is at least partially formed integrally with the impeller vane unit 16a. The protective unit 20a comprises a contour element 21a of the impeller vane 18a. The contour element 21a completely forms a front edge 22a of the im- peller vane 18a. Alternatively, the contour element 21a could merely form a part of the front edge 22a. The protective unit 20a comprises two shielding elements 40a, which are identical to one another, which is why in the following merely one of the shielding elements 40a is described. The shielding element 40a is provided to at least encumber objects entering a region between a radial outer side of the impeller vane 18a and at least one wall 42a of the conduction unit 12a. The shielding element 40a is formed integrally with the line unit 12a. Alternatively, the shielding element 40a could be configured as a separate element and attached to the conduction unit
12a. The shielding element 40a connects an outer sub-region 78a with the wall 42a. The wall 42a has a higher diameter than the outer sub-region 78a. The wall 42a is configured linearly. Alternatively, the wall 42a could also be formed arc-shaped. The Figures 3a to 3e show different schematic representations of the impeller vane
18a. The impeller vane 18a comprises a mounting element 62a. The mounting
= 14 - element 62a contributes to an attachment of the impeller vane 18a to the impeller vane hub 58a. The mounting element 62a, in a mounted state, is completely located within the impeller vane hub 58a. The impeller vane 18a comprises a vane leaf 64a. The vane leaf 64a comprises a first main surface 28a and a second main surface
38a. The main surfaces 28a, 38a arranged located opposite one another. The impel- ler vane 18a comprises an outer edge 60a. The outer edge 60a connects both main surfaces 28a, 38a with one another. The outer edge 60a defines the radial outer side of the impeller vane 18a. The vane leaf 64a comprises a first leaf region 66a and a second leaf region 68a. The outer edge 60 defines a common edge of both leaf regions 66a, 68a. The im- peller vane 18a is rotationally non-symmetrical. The first leaf region 66a and the second leaf region 68a are configured distinct from one another. Alternatively, both leaf regions 66a, 68a could also be configured identical to one another. With a view perpendicularly onto the main surfaces 28a, 38a, the first leaf region 66a comprises a substantially linear rear edge 70a. The second leaf region 68a comprises a front edge 22a. The front edge 22a is configured arc-shaped. Alternatively, the front edge 22a could also comprise corners and/or multiple different curvature directions. The front edge 22a is realized in a sickle shape. In a tip 74a, the front edge 22a meets the outer edge 60a. The second leaf region 68a is realized in a sickle shape. In the operative position, the front edge 22a penetrates a plane 24a extending perpendicularly to the rotation axis 14a in an intersection point 26a. Upon an imaginary movement of the plane 24a parallel to the rotation axis 14a, the intersection point 26a is displaced radially non-uniformly in the direction of the rotation axis 14a. Alternatively, the intersection point 26a could also be displaced uniformly. With the view perpendicularly onto the main surfaces 28a, 38a of the impeller vane 18a and an imaginary movement of a point (not shown) from one end of the front edge 22a to a further end of the front edge 22a, a movement direction of the point rotates by approximately 80°. Alternatively, the movement direction of the point could rotate by 100° or 200°. A first movement direction 30a of the point at the end
= 15 - of the front edge 22a and a second movement direction 32a of the point at the fur- ther end of the front edge 22a jointly define an angle of approximately 80°. With a view perpendicularly onto the main surfaces 28a, 38a of the impeller vane 18a, a maximum perpendicular distance 34a between a connecting line 36a of two end points of the front edge 22 and any remaining points of the front edge 22a amounts to approximately 40% of a length of the connecting line 36a. Alternatively, the perpendicular distance 34a could amount to 60% or 80% of a length of the connecting line 36a. The front edge 22a has a rounding. The rounding connects the first main surface 28a of the impeller plate 18a with the second main surface 38a of the impeller vane
18a. A thickness of the front edge 22a increases radially in the direction of the rotation axis 14a. The rounding flattens out proportionally to the increase of the thickness of the front edge 22a. The thickness of the front edge 22a increases radi- ally in the direction of the rotation axis 14a by approximately 1000%. Alternatively, the thickness of the front edge 22a could increase radially in the direction of the rotation axis 14a by approximately 200% or 1200%. In Figure 4, a schematic flow diagram of a method for designing the hydropower plant 44a is shown. In a design step 100a, the hydropower plant 44a is equipped with the turbine device 10a. A reduction of efficiency because of the use of the turbine device 10a is compensated by dispensing with a further protective measure. In this case, the further protective measure is the equipping of the hydropower plant 44a with flotsam rakes. In the Figures 5 and 6 a further exemplary embodiment of the invention is shown. The following descriptions and the drawings are substantially limited to the differ- ences between the exemplary embodiments, wherein with respect to identically de- noted components, in particular with respect to components having same reference signs, reference can basically be made to the drawings and/or the description of the other exemplary embodiments, in particular of the Figures 1 to 4. To distinguish the exemplary embodiments, the letter a is suffixed to the reference signs of the
= 16 - exemplary embodiment in the Figures 1 to 4. In the exemplary embodiments of the Figures 5 to 6, the letter a is replaced with the letter b.
Figures 5 and 6a to 6e show a schematic representation of a part of a further turbine device 10b.
The further turbine device 10b comprises a further impeller vane unit 16b with further impeller vanes, of which in the following merely one further im- peller vane 18b is described.
The further impeller vane 16b is free of vane rings.
The further impeller vane 18b is free of guide elements.
The further impeller vane 18b is immovably connected to a further impeller vane hub 58b.
Reference signs 10 Turbine device 12 Conduction unit 14 Rotation axis 16 Impeller vane unit 18 Impeller vane Protective unit 21 Contour element 20 22 Front edge 24 Plane 26 Intersection point 28 Main surface 30 Movement direction 32 Movement direction 34 Distance 36 Connecting line 38 Main surface 40 Shielding element 42 Wall 44 Hydropower plant 46 Dam 48 Power house
= 17 - 50 Inlet opening 52 Outlet opening 54 Shaft 56 Generator 58 Impeller vane hub
60 Outer edge 62 Mounting element 64 Vane leaf 66 Leaf region
68 Leaf region 70 Rear edge 72 Stabilization element 74 Tip 78 Sub-region
80 Vane ring 100 Design step ok kkk