WO2022018046A1

WO2022018046A1 - Hydraulic power plant

Info

Publication number: WO2022018046A1
Application number: PCT/EP2021/070187
Authority: WO
Inventors: Mikael Rüdlinger
Original assignee: Rv Lizenz Ag
Priority date: 2020-07-21
Filing date: 2021-07-19
Publication date: 2022-01-27
Also published as: CH717747A2

Abstract

A buoyant power plant unit (1) for generating electrical energy from a directional water flow (91) at the surface of a body of water (90) comprises at least one float element (20); at least one water prime mover (40) for driving an electricity generator (41); a build-up device (70) which is supported by the at least one float element and by means of which, in the case of the power plant unit spatially fixed in relation to a surface flow (91) of a body of water (90), inflowing (98) water can be conducted upward in relation to a local water level (96) of the body of water and can be built up perpendicularly with respect to the flow direction (92a, 92b) to form a first standing water wave (94a) on a first side of a reference plane (14); and a first supply device (42a) for diverting water from the first standing wave into the at least one water prime mover.

Description

POWER PLANT

field of technology

The present invention relates to buoyant power plant units for generating electrical energy from a directed flow of water on the surface of a body of water, and corresponding methods.

Technological background

There are a number of different options for generating renewable energies, which can be relevant in different ways depending on local conditions. One such source of renewable energy is hydroelectric power. For the most part, hydroelectric power plants are used, in which water is dammed with dams. Depending on the available flow rate and head, different types of water turbines are used to convert the potential energy and/or kinetic energy of the dammed water as efficiently and effectively as possible into kinetic energy of the rotating turbine, which in turn generates electrical energy using electricity generators.

Also known are tidal power plants, in which bays with a high Ti denhub are completed by barrages in order to use the tidal currents in both directions to generate energy using water turbines. There are only a few technically suitable locations for such large-scale plants. Larger hydroelectric power plants require complex fixed infrastructure with correspondingly high investment costs. This makes a correspondingly long planning horizon necessary. The impact on the environment is usually significant, which can cause corresponding political resistance. In remote locations, on the other hand, maintenance and logistics are often very complex. Hydroelectric power plants have also been developed to utilize existing directional tidal currents in marine waters for energy without the need for construction of complex barriers. Such power plant units, which are small in comparison to the aforementioned tidal range power plants, use turbines or rotors arranged directly in a water flow to drive the power generators. In some cases, they can also be used to utilize the flow in rivers. They can be divided into different types based on their arrangement or attachment in the body of water.

In one type of such power plants, the relevant devices are mounted on a support structure arranged on the ground. By way of example, US Pat. No. 5,440,176 shows a system with a plurality of Kaplan-like turbines arranged in the water flow on a supporting structure. WO 2014/130840 A1 discloses a rotor arranged in the flow, which is fixed on a mast anchored on the ground.

Alternatively, turbine nacelles or rotor nacelles are arranged floating or hanging in the open water, as disclosed in US 2007/096472 A1 and GB 2256011 A, for example.

For the maintenance of the aforementioned systems, the system parts must be recovered from the water, which is expensive.

In another type of power plant, structures projecting downwards into the water are used on a floating platform to support the rotor and turbine units. Such systems are known, for example, from DE 2635529 A1 and WO 2004/104411 A1. The resulting draft of such floating systems is considerable. Such device tongues are therefore not very suitable for shallower water depths such as, for example, in rivers. If the water levels are temporarily lower, there is also a risk of ground contact and the resulting damage.

There is a general need for improvement in this area.

PRESENTATION OF THE INVENTION One object of the invention is to provide a buoyant power plant unit of the type mentioned at the outset which does not have the above-mentioned and other disadvantages. In particular, a power plant unit according to the invention should be able to be produced more quickly and cost-effectively and be easier to transport and maintain. Furthermore, such a power plant unit should be easily adaptable to changing conditions.

A power plant unit according to the invention should be suitable for using surface currents in bodies of water, for example tidal currents, but also flow currents in rivers, for the generation of electrical energy.

A power plant unit according to the invention should be as maintenance-friendly and low-maintenance as possible.

The ecological effect of a power plant unit according to the invention should be as small as possible. These and other objects are achieved by a buoyant power plant unit according to the invention and a method according to the invention according to the independent claims. Further advantageous embodiments also emerge from the dependent claims and the description.

The solution according to the invention can be further improved by various configurations that are advantageous in and of themselves and, unless stated otherwise, can be combined with one another as desired. These embodiments and the advantages associated with them are discussed below.

A first aspect of the invention relates to a buoyant power plant unit for generating electrical energy from a directed flow of water on the surface of a body of water. The buoyant power plant unit comprises at least one float; at least one hydroelectric power machine for driving a power generator; a damming device carried by the at least one floating body, with which, in the case of the power plant unit that is locally fixed in relation to a surface current of a body of water, inflowing water can be guided upwards in relation to a local water level of the body of water and to a first standing water wave on a first side a reference plane perpendicular to the direction of flow can be stacked; and a first delivery device for discharging water from the first standing wave into the at least one hydroelectric power machine.

Such a buoyant power plant unit according to the invention is intended to be fixed in place floating on a body of water, for example by suitable anchorages on the bottom or on the bank of the water body. The Kraftwer unit is aligned for the inventive operation in relation to the direction of flow on the surface of the body of water such that the impounding device dams the inflowing water on the surface to a standing wave whose crest level is above the local water level. The damming device thus converts the kinetic energy of the water flow into potential energy in the form of a pressure drop between the wave crest and the local water level.

The standing wave represents a dynamic equilibrium as a result of the relative movement between the body of water and an obstacle in the form of the power plant. However, a continuous barrage is not necessary. The potential energy of the water can in turn be converted into electrical energy by diverting water from the standing wave into a hydroelectric power machine.

The electrical current generated by a power plant unit according to the invention is fed into the grid via suitable lines and in a suitable form. Corresponding techno logies are known, for example, from the application for offshore wind power plants.

A power plant unit according to the invention can be used at different flow speeds, for example from 0.5 m/s to 5 m/s.

The formation of the standing wave can also be influenced by the angle of attack of the entire storage device, which can be achieved, for example, by changing the water position of the power plant unit with adjustable floats. These will be discussed further.

In addition to the volume flow that is diverted to the hydroelectric power machine, part of the volume flow can also flow around the obstacle that the power plant unit represents, in particular over the impoundment device, in the sense of an overflow, or past the side or under the power plant unit.

The damming device can be arranged parallel to the reference plane. However, it can also be concave or convex in relation to the flow direction, with the specific design being advantageously optimized with a view to the greatest possible fall height.

It is also possible to arrange several power plant units according to the invention next to one another in the direction of flow and/or one behind the other in a body of water Sufficient distance must be observed so that the individual power plant units do not negatively influence each other's effectiveness. This is particularly important because standing waves are a dynamic effect. For example, if a power plant unit is located too close behind another power plant unit downstream, the resulting flow shadow of the power plant unit upstream can reduce the height of the standing wave.

Since the water can pass between the ground and the power plant unit, the impact on the ecology is much lower than with a dam or a plant that is arranged on the water bed. The fish-friendliness of a power plant unit according to the invention can be guaranteed by a suitable choice of the water power machine, for example by large, slowly rotating rotor blades. The passage of larger animals, but also flotsam, wood or nets can be reduced by raking.

Floating power plant units according to the invention are mobile, since no fixed installations are necessary, apart from anchoring points, if necessary, and can be towed to other locations if necessary. For more complex maintenance work, power plant units according to the invention can be towed into a port or a dock.

The dimensioning of a power plant unit according to the invention can be selected depending on the area of use. For larger bodies of water, such as larger rivers or locations at sea with strong tidal currents, systems with larger dimensions can be used. The size of a power plant unit according to the invention is advantageously selected such that it can be set up and maintained in a conventional dock.

In order to make it more difficult for the water flow to flow around a power plant unit according to the invention, the front side facing the oncoming water is advantageously designed to be as wide as possible.

For this purpose, for example, a power plant unit according to the invention can be created by reversible or irreversible coupling of individual buoyant modules. In a simple variant, for example, modules can be moored together in the longitudinal direction (parallel to the direction of flow), but mechanical ones are also possible Couplings for the positive and/or non-positive connection of modules to form a power plant unit can be provided.

A power plant unit according to the invention can be constructed, for example, from three individual power plant units each having a width of 12-14 m, a height of 4-6 m and a length of 40-60 m. The overall width of the front of the entire power plant unit is advantageously five to six times the height of the power plant unit.

In another dimensioning example, the width of a power plant unit according to the invention is 30 m, the length is 40 m and the draft is 12-15 m.

The individual modules can be designed as independent power plant units according to the invention. By coupling several individual power plant units, the size of an entire power plant unit can be scaled.

Advantageously, in a power plant unit according to the invention, the impoundment device is constructed essentially mirror-symmetrically, so that when the direction of flow of the surface current of the body of water is reversed, water flowing from an opposite direction of flow can be guided upwards with the impoundment device in relation to the local water level of the body of water and to a second stand the water wave is aufstaubar on a second side of the reference plane. A second supply device is provided for diverting water from the second standing wave into the at least one hydroelectric power machine.

Such an advantageous embodiment of a power plant unit according to the invention has the advantage that when the flow direction is reversed by 180°, the power plant unit remains operational without the orientation of the power plant unit having to be changed in relation to the flow direction. A reversal of flow direction occurs in tidal currents, four times in about 25 hours. Tidal currents can also occur in rivers near the sea, where they can interfere with and temporarily reverse the direction of river flow. When changing the direction of flow, the power unit according to the invention can be switched between two corresponding operating modes. This is further discussed below.

Alternatively, a power plant unit according to the invention can also be fixed in the body of water in such a way that it automatically aligns itself in the direction of flow. In such a In this case, however, it must be able to rotate around a single fixation point, which is possible, for example, with a single anchorage on the bottom of the water. Such a solution requires more space, since it must be ensured that a power plant unit cannot collide with any obstacles when changing its position and orientation.

Advantageously, the damming device of a power plant unit according to the invention has a barrier arranged on an upper side of the power plant unit opposite the body of water, for damming up the inflowing water.

Such a barrier, in the simplest case a wall parallel to the reference plane perpendicular to the direction of flow, which is arranged on the upper side of the power plant unit, forms an obstacle for surface water flowing against it, which leads to a standing wave.

It is also advantageous if the damming device of a power plant unit according to the invention has at least one guide element arranged on an upper side of the power plant unit opposite the body of water, with which inflowing water can be guided to the barrier.

Such a guide element can be designed, for example, as a vertical wall parallel to the direction of flow, which prevents or reduces the inflowing water from escaping transversely to the direction of flow. For example, two guide walls can be arranged upstream of a barrier of an impounding device on both sides of the barrier, which prevent flow around the barrier.

In another advantageous embodiment of a power plant unit according to the invention, the damming device has a ramp arranged on an upper side of the power plant unit opposite the body of water. Such a ramp, which rises in the direction of flow, can direct the inflowing water upwards against gravity and thus convert its kinetic energy into potential energy. Functionally, such a ramp can be considered both as part of a barrier of the damming device and as a guiding element.

In a particularly advantageous embodiment of a power plant unit according to the invention, the damming device has a damming device located opposite the body of water Top of the power plant unit arranged ramp, which is laterally limited by a vertical right baffle.

The angle of inclination of the ramp in relation to the horizontal is advantageously 0° at the beginning of the ramp, on the front side of the power plant unit, and is below the water line during operation. The slope of the ramp then steadily increases to 45°, exceeding the waterline, eventually turning the ramp into a barrier.

The ramp and the lateral guide walls thus form a channel in the direction of flow, into which the inflowing water enters. Without wanting to be bound by the following explanation, the thickness of the turbulent flow in the water flow on the surfaces of the channel (the ramp and the side walls) increases with increasing ramp in the channel, which additionally reduces the channel volume for inflowing water and the water rises upwards dodge. Finally, the oncoming wave comes to a standstill in the stationary wave, which can also cause surf effects.

A rake can be arranged on the front surface of the channel in order to prevent larger objects from getting into the channel in the first place.

If the crest of the standing wave is above the crest of the barrier, some of the water in the standing wave drains over the barrier. On the one hand, this limits the height of the standing wave to a maximum operating value and, on the other hand, has the advantage that floating foreign bodies can, in the best case, be washed over the barrier.

In a power plant unit according to the invention, the feed device advantageously has a feed pipe which runs from an opening in the damming device to the at least one water power machine.

Water accumulated in the standing wave can thus be removed from the standing wave and routed to the hydroelectric power machine, where the potential energy of the water resulting from the drop height between the crest level of the standing wave and the hydroelectric power machine is converted into kinetic energy.

The opening through which the water flows out of the standing wave into the supply pipe is preferably provided with a rake in order to prevent foreign bodies from entering the hydroelectric power machine. The at least one hydroelectric power machine of a power plant unit is advantageously a Kaplan turbine or a Kaplan-like turbine.

Kaplan turbines and Kaplan-like turbines offer the advantage that they can work efficiently even at comparatively low heads, such as those that occur in run-of-river power plants, and can be adapted to fluctuating operating parameters such as head or flow rate. This is advantageous in a power plant unit according to the invention, since strong fluctuations occur over the course of the day, particularly in the case of tidal currents.

Kaplan turbines convert potential energy in the form of water pressure into kinetic energy of the rotor. Kaplan turbines have adjustable (rotatable) rotor blades so that the turbine can operate at optimum efficiency with fluctuating flow rates and/or run at a constant speed, which in particular enables direct injection into the power grid. There are also variants of Kaplan turbines in which the rotor blades cannot be adjusted, whereby an adjustment to the flow rate can be achieved in this case by changing the speed, but an AC converter is required to feed the generated electrical energy into the grid power. Also possible in the aforementioned Kaplan turbines is the additional control of the non-rotating guide vanes in order to adapt the turbine to fluctuating operating parameters.

The VLH (Very Low Head) turbine, as known from US 2007/286715 A1, is a Kaplan-like turbine which is particularly suitable for low heads and has a low rotational frequency, which makes it easier for fish to pass through the turbine. The flow rate is regulated and the efficiency is optimized by adjusting the rotor blades and regulating the rotational frequency. The generator is arranged inside the impeller to save space.

Instead of turbines of the Kaplan type, other water power machines can also be used which can work efficiently at comparatively low heads, for example cross-flow turbines as disclosed for the first time in DE 605291, or worm-drive water power machines as disclosed in DE 4139134 A1. In an advantageous form of a power plant unit according to the invention, a pipe is arranged downstream of the turbine, with which the water can be carried away after it has passed the turbine.

For example, the water emerging from the water power machine can be fed back into the body of water below the water line via the pipe mentioned, which minimizes the noise development.

In a further advantageous form of a power plant unit according to the invention, a suction pipe is arranged downstream of the water power machine, which opens below the water level towards the body of water. In the case of turbines of the Kaplan type in particular, such intake pipes serve as a diffuser to dissipate residual energy in the water in order to prevent damage to the system, for example due to cavitation. Furthermore, a backflow of water should also be prevented.

A power plant unit according to the invention can comprise one or more floating bodies, with a floating body being understood in the context of this description as any element generating static buoyancy, in particular both non-closed hulls and pressure-tight closed hollow bodies.

In an advantageous embodiment of a power plant unit according to the invention, a device is provided with which a floating body can be moved in relation to the damming device.

Such an embodiment of a power plant unit allows to change the location of the damming device in relation to the waterline. Floating bodies can be provided, for example, which are moved or rotated with a suitable drive relative to a main structure of the power plant unit, which also includes the impounding device, in order to increase or decrease the buoyancy of the power plant unit.

Several floating bodies can also be provided, which are arranged in such a way that, when actuated separately, they not only allow the entire power plant unit to be raised and lowered in relation to the waterline, but also tilting. Ballast tanks can also be provided, which enable the buoyancy of the power plant unit to be controlled by targeted flooding and emptying. Since the actuation of such ballast tanks is more complex and slower, they are particularly suitable for long-term position optimization.

Adaptive water level adjustment can be used to compensate for the changing weight of the standing wave on top of the power plant unit, as well as a shifting center of mass.

Adaptive adjustment of the water level can also be used to bring a power plant unit into a secure state in unfavorable weather conditions such as a storm, for example by temporarily maximizing the buoyancy.

Dynamic drive elements can also be provided in order to set and control the water position of a power plant unit according to the invention, in particular horizontal lift or downforce wings, advantageously with an adjustable angle of attack or other operating parameters.

Rudders as passive controls but also active controls such as screw drives or propulsion nozzles can be provided in order to adjust and control the alignment of a buoyant power plant unit with respect to the direction of flow.

Advantageously, a first device is provided in a power plant unit according to the invention, with which the water power machine can be fluidically connected alternately to a first feed pipe and a second feed pipe.

Such an embodiment makes it possible to provide two different operating modes for a power plant unit according to the invention, in which the water power machine obtains the pressurized water required for its drive either from two different sources. For example, in one embodiment of a power plant unit according to the invention, which has a symmetrical impoundment device, if the tidal flow changes by 180° and the first standing wave on one side of the impoundment device is eliminated and a second standing wave forms on the other Side of the damming device, the supply for the water power machine can be switched so that water instead of from the no longer existing first standing wave can be derived from the second standing wave in the hydroelectric power machine.

A second device is also advantageously provided in a power plant unit according to the invention, with which the water power machine can be fluidically connected alternately to a first pipe arranged downstream of the turbine and a second pipe arranged downstream of the turbine.

Such an embodiment of a power plant unit according to the invention is particularly advantageous when the power plant unit has to be switched from an operating mode with a first standing wave to an operating mode with a second standing wave. In order to enable problem-free drainage of the water emerging from the water power machine, the drainage direction of the water, generally downstream, is advantageously changed by 180°. This can be achieved with a switchable outgoing pipe.

A second aspect of the invention relates to a method for generating electrical energy from a directed flow of water on the surface of a body of water. Such a method comprises the provision of an impounding device carried by at least one floating body, which is fixed in place with respect to a surface current of a body of water. Incoming water is directed upwards by the damming device with respect to a local water level of the body of water and is dammed to form a standing water wave. Water from the standing water wave is diverted into a hydroelectric power machine. Electrical energy is generated with a power generator driven by the hydroelectric power machine.

The method according to the invention is advantageously carried out with a power plant unit according to the invention.

Further aspects of the present invention also result from the following description. Brief description of the drawings

For a better understanding of the present invention reference is made to the undersigned references. These merely show exemplary embodiments of the subject matter of the invention and are not suitable for restricting the invention to the features disclosed herein.

The same or similar reference symbols are used in the following figures and the associated description for parts that are the same or have the same effect.

FIG. 1 schematically shows an advantageous embodiment of a power plant unit according to the invention in a longitudinal section. FIG. 2 schematically shows a front view of the power plant unit according to the invention from FIG. 1, viewed from the direction of the inflowing water.

FIG. 3 schematically shows, in a longitudinal section, another advantageous embodiment of a power plant unit according to the invention, with an essentially symmetrical structure of the damming device. FIG. 4 schematically shows, in a longitudinal section, a further advantageous embodiment of a power plant unit according to the invention, with an essentially symmetrical structure of the damming device.

FIG. 5 schematically shows an advantageous switchable water supply device for a vertical Kaplan turbine, (a) in a cross section, and (b) in a section through the horizontal section plane A-A.

FIG. 6 schematically shows an advantageous switchable water discharge device for a water power machine, (a) in a cross section and (b) in a plan view. implementation of the invention

An advantageous embodiment of a power plant unit 10 according to the invention is shown schematically in FIGS. The power plant unit 10 is floating in a Ge water 90 fixed in place. The corresponding fixing means are not shown, but the known means for anchoring floating bodies can be used. It is possible, for example, to fix it at four points on the power plant unit, which are connected to anchoring elements on the bottom of the water body via anchor chains.

The power plant unit 10 is arranged with its longitudinal axis parallel to the flow direction 92a of the surface water flow 91 of the body of water.

On a first box-shaped floating body 20 on the bottom 13 of the power plant unit 10 facing the body of water 90, a damming device 70 is constructed. The floating body shown purely schematically in the figures must be dimensioned in such a way that the position of the water in the power plant unit is correct, possibly in conjunction with other floating bodies 20', 20''.

Two additional floating bodies 20', 20" are arranged laterally along the longitudinal axis of the power plant unit. The floating bodies 20', 20" can be lowered or raised in relation to the rest of the power plant unit by means of devices not shown, which changes the overall buoyancy of the power plant unit accordingly. For example, actuation by means of hydraulic actuators or chain drives is possible.

The impounding device 70 comprises a ramp 73a, which begins at the bow side 13a with a gradient of 0° and becomes steeper downstream until it merges into a barrier 71. Four vertical guide walls 72a together with the ramp 73a form three channels through which the water 98 flowing in from the bow side 13a is directed downstream. In the area of the standing wave, the baffles 72a prevent the water from flowing off to the side, so that the achievable backwater height is greater.

The barrier 71 runs parallel to a virtual reference plane 14 perpendicular to the longitudinal axis of the power plant unit or the flow direction 92a of the surface water flow 91. Initially, the channels of the dam are below the waterline 96, but then rise steadily downstream so that the water flow 98 is directed against gravity upwards over the waterline 96 due to its kinetic energy. The speed of the water flow 98 steadily decreases until finally the water comes to a standstill in the standing wave 94a. When the crest height 95a of the standing wave 94a reaches the height of the barrier 71, some of the water continues to drain over the barrier.

Depending on the geometry of the barrier and the flow speed, surf effects can occur if part of the water has to flow back due to geometric constraints and the standing wave breaks up. The breaking of the standing wave is energetically unfavorable, since part of the potential energy of the standing wave is converted into thermal energy and is thus lost for energy generation. The geometry and the other parameters of the power plant unit are therefore advantageously selected in such a way that breaking can be avoided as far as possible. Arranged in the barrier 71 are openings 74a covered with rakes 47, through which water can flow out of the standing wave 94a into a shaft 43a of a feed device 42a, which directs the water to a water power machine in the form of a Kaplan turbine 40. The set in rotation rotor of the turbine in turn drives a generator 41, which generates electrical energy. A suction pipe 44a is arranged downstream of the turbine 40, which reduces the residual energy of the water and opens 55a on the stern side 13b to the body of water.

In the exemplary embodiment shown, the power plant unit is constructed in one piece. Alternatively, it would also be conceivable to couple three separate modules to one another along the longitudinal axis. The shape of the power plant unit is advantageously chosen so that the flow resistance and the formation of turbulence is as low as possible, so that the fixing means with which the power plant unit is fixed in the water flow can be dimensioned to a minimum.

The power plant unit discussed above is particularly suitable for generating energy in rivers where there are no tides, i.e. the direction of flow remains the same over the long term. A symmetrical structure of the impounding device is advantageous for areas of application in which the direction of flow changes regularly, i.e. for the use of tidal currents, but also in rivers influenced by tides. Such an embodiment of a power plant unit according to the invention is shown schematically in FIG.

The damming device 70 with ramp, guide walls and barrier is realized in a manner similar to that shown in FIGS.

In FIG. 3, the power plant unit is in a first operating mode, in which the direction of flow 92a runs from left to right. A first standing wave 94a forms on a first side 15a of the damming device 70 . Water 98 flows from the first standing wave 94a through a first opening 74a in the barrier into a first feed tube 43a of a feeder which feeds the water into a hydroelectric power machine in the form of a Kaplan turbine 40 disposed vertically. The water exiting the turbine flows off via a first suction pipe 44a, which empties itself through an opening in the barrier downstream to the rear side 13b.

Due to the symmetrical structure, an opening 74b is also arranged on the barrier downstream. From this second opening 74b, a second feed pipe 43b leads to the turbine 40. Downstream of the turbine, in turn, a second suction pipe 44b leads to an opening in the upstream barrier. Since the second feed pipe 43a and the second suction pipe 44a have no function in the first operating mode, switching devices 45, 46 are provided which deactivate the second feed pipe 43b and the second suction pipe 44b in the first operating mode shown, or the first feed pipe 43a in the second operating mode and deactivate the first intake manifold 44a. In the example shown, these switching devices are implemented by suitably placed plate-shaped slides 48, 49, which can be closed to deactivate the supply pipe or suction pipe.

When the direction of flow of the surface water flow 91 turns by 180° from 92a to 92b, this does not happen suddenly, but at a previously known point in time. Closing all slides 48, 49 ends the first operating mode and temporarily disables the water power machine. After the first standing wave 94a has drained and the second standing wave 94 has formed on the second side 15b, the pushers 48, 49 for the second feed tube 43b and the second Suction pipe 44b is opened, while now the first supply pipe 43a and the first suction pipe 44a remain deactivated when the slider 48 or 49 is closed. The power plant unit is now in the second operating mode.

Instead of closing all the slides when switching over, the slides of one or both pairs of slides 48, 49 can both be open. When changing from one operating mode to the other, the sequence in which the valve opens and closes must be selected in such a way that damage to the system, in particular to the hydroelectric power machine, is not possible, for example due to undesired backflows or the formation of negative pressure. The shown implementation of the switching devices 45, 46 for the water supply and water discharge of the water power machine by means of plate-shaped slides 48, 49 is easy to implement, but not particularly ideal in terms of flow technology. More advantageous design options for switching devices 45, 46 are described below in FIGS. 5 and 6. FIG. 4 shows a further power plant unit according to the invention with a substantially symmetrical design of the impounding device. The power plant unit is in a first operating mode, in which the flow direction 92a runs from left to right. On the first side 15a of the damming device 70, a first standing wave 94a forms, from which water 98 flows through a first opening 74a in the barrier into a first feed pipe 43a of a feed device. The hydroelectric power machine 40 is again a vertically arranged Kaplan turbine.

The formation of the standing wave 94a is controlled by a pivotable first gate 75a. A second pivotable storage flap 75b is in the rest position. The first pivoting flap 75a is advantageously pivoted upwards from the horizontal rest position by an actuator device such that the height of the standing wave is as high as possible for a given amount of discharge into the feed device 43a without the standing wave breaking. As a result, the static water pressure at the entrance to the hydroelectric power machine 40 becomes maximum. Avoiding the breaking of the standing wave, in turn, avoids wasting energy by converting potential energy into unusable thermal energy. A small portion of the water from the standing wave flows over the barrage and onto the opposite side of the damming device 70 down the ramp 73b, where the corresponding flow of water flows into the stern water 97.

The storage flaps 75a, 75b can be implemented as plates, or alternatively in the form of a lattice structure or a plate with through-openings or slots, for example horizontal or vertical slots. A plurality of rods arranged at a small distance from one another can also be used as a storage flap. The use of such grid-like dam flaps has the advantage that the dam flap does not completely slow down the water flowing forward in the direction of flow, but instead increases the flow resistance. This also leads to a damming effect, with the amount of water flowing over the damming device and/or its speed being greater at the same time. This can be beneficial in terms of preventing the standing wave from breaking. The remaining flow velocity in the standing wave and the resulting dynamic pressure can also further increase the energy efficiency of the system.

A second switching device 46 in the form of a vertically rotatable valve body 53 is arranged below the turbine. The functional principle of this two-way valve is analogous to the switching device as described in detail in FIG.

The water exiting the turbine flows off via a first suction pipe 44a, which empties into the stern water on the stern side 13b. In the embodiment shown, the suction pipe 44a of the power plant unit 10 according to the invention runs within the lower floating body 20. The result is a lower-lying outlet opening 55a of the suction pipe, which is located at the very end of the floating body just below the level 97 of the stern water. The water emerging from the first suction pipe 44a is sucked in due to the negative dynamic pressure in the stern water, which further increases the energy efficiency.

The second suction pipe 44b is arranged symmetrically and opens towards the bow side 13a. In the example shown, the opening 55b of the second suction pipe 44b is open to the flow 92a. This in itself has no effect on the operation of the water power machine 40, since the suction pipe 44b is closed by the switching device 46. However, in order to optimize the flow resistance of the entire power plant unit, the opening can be covered by a suitable closure device. The intrusion of Foreign bodies in the second intake manifold, on the other hand, are not a problem, since such foreign bodies are simply flushed out of the intake manifold when the operating mode is switched.

In the exemplary embodiment shown, the length of the stern water 97, i.e. the zone of the lower local water level downstream due to the water displacement of the power plant unit fixed in the flow, is longer than in the aforementioned examples and is, for example, 1/3 the length of the power plant unit. A local water level in the stern water that is as low as possible allows the negative pressure difference between the output of the turbine 40 and the opening 55a of the suction pipe 44b to be maximized in the stern water, which increases the efficiency of the water power machine.

Advantageously, the position of the turbine 40 in relation to the height of the inlet opening 74a, 74b and the height of the outlet 55a, 55b of the suction pipe 44a, 44b is chosen so that the head of the inflowing water is sufficient for the operation of the turbine, and at the same time the head between the turbine outlet and the suction pipe outlet 55a, 55b maximum.

An advantageous switching device 45 for the water supply of a vertically arranged Kaplan turbine 70 in a power plant unit according to the invention is shown in FIG. An annular chamber 52 serves to impart a suitable swirl to the inflowing water before it passes through the guide vanes 51 . The first feed tube 43a and the second feed tube 43b are aligned so that the water entering the chamber 52 flows around in the correct direction. A semi-circular gate valve 48 closes the first feed pipe 43a while water is allowed to flow into the chamber from the second feed pipe 43b. In FIG. 5, the system is therefore in the second operating mode.

The slider forms a flush outer wall without any protruding structures with the wall section of the ring-shaped chamber 52 lying at the bottom in FIG. 5(b).

To switch from the second operating state to the first operating mode, the arcuate slide 48 is rotated about the axis of rotational symmetry of the annular chamber 52, which here coincides with the longitudinal axis of the turbine. In the final position of the slide 48 shown in dashed lines is then the second Feed pipe 43b closed while the water can flow from the first feed pipe 43a into the chamber 52.

With the switching device shown, it is not possible to close both feed pipes 43a, 43b at the same time. This would require two separate sliders. However, it is not necessary to close them at the same time. A common slide is also simpler in design, since only one actuator is required. Separate slides, in turn, would be less optimal in terms of flow technology, since protruding edges would result in the outer wall of the chamber 52, which would reduce the efficiency of the water power machine. An advantageous switching device 46 for selectively diverting the water flow emerging from a hydroelectric power machine of a power plant unit according to the invention, for example a vertically arranged Kaplan turbine, is shown in FIG.

The switching device 46 works according to the principle of the two-way valve. A suction pipe 44 guides the water flowing out from the upstream hydraulic power machine to the switching device 46, which can fluidly connect the suction pipe 44 by turning a cylindrical valve body 53 by 180° with a first downstream suction pipe 44a and a second downstream suction pipe 44b. The valve body 53 is realized in the example shown as a curved bore in a solid cylindri's block. In a less expensive embodiment, a suitably shaped curved pipe section is mounted in a pivoted support structure.

A sealing of the connections between the suction pipes 44, 44a, 44b and the valve body 53 can be achieved, for example, by labyrinth seals.

Alternatively, the exemplary embodiment shown can also be brought into a closed configuration by rotating the valve body by only 90°, in which the three intake pipes 44, 44a, 44b are fluidically separated.

The switching device 46 from FIG. 6 can also be used to switch between two feed pipes 43a, 43b. The present invention is not limited in scope to the specific embodiments described herein. Rather, for the person skilled in the art, from the description and the associated figures, in addition to the examples disclosed here, there are various further modifications of the present invention that also fall within the scope of protection of the claims. In addition, various references are cited in the description, the disclosure content of which is hereby incorporated in its entirety by reference into the description.

Reference List

10 power plant unit

11 top

12 bottom

13a first bow side, first side facing the current

13b Stern side, second side facing away from the current

14 Reference plane, vertical plane perpendicular to the direction of flow

15a first page

15b second page

20, 20', 20” float

40 hydroelectric machine

41 power generator 42a first feeder 42b second feeder

43a, 43b supply pipe 44, 44a, 44b suction pipe

45 first switching device

46 second switching device

47 rakes

48 sliders

49 sliders

50 Turbine

51 empennage

52 annular chamber

53 valve body

55a, 55b outlet of the intake manifold

70 impoundment device

71 barrier

72a, 72b guide element 73a, 73b ramp 74a, 74b opening 75a, 75b storage flap

90 bodies of water

91 surface water flow

92a, 92b direction of flow 94a, 94b standing wave 95a, 95b level of standing wave

96 local water level of the body of water

97 Water level in the stern water of the power plant unit

98 oncoming water

Claims

patent claims

1. Floating power plant unit (1) for generating electrical energy from a directed water flow (91) on the surface of a body of water (90), comprising at least one floating body (20); at least one water power machine (40) for driving a power generator (41); a damming device (70) carried by the at least one floating body, with which, in the case of the power plant unit that is locally fixed in relation to a surface flow (91) of a body of water (90), inflowing (98) water is pumped in relation to a local water level (96) of the Water can be directed upwards and to form a first standing water wave (94a) on a first side of a reference plane (14) perpendicular to the direction of flow (92a, 92b); and a first supply device (42a) for discharging water from the first standing wave into the at least one hydroelectric power machine.

2. Power plant unit according to claim 1, wherein the damming device (70) is constructed essentially mirror-symmetrically, so that when the flow direction of the surface flow (91) of the body of water (90) is reversed, water (98 ) with the damming device () in relation to the local water level (96) of the body of water can be guided upwards and to a second standing water wave (94b) on a second side (15b) of the reference plane; and wherein a second supply device (42b) is provided for discharging water from the second standing wave into the at least one hydroelectric power machine (40).

3. Power plant unit according to claim 1 or 2, wherein the impounding device (70) has an upper side (11) of the power plant unit (10) arranged opposite the body of water (90) for impounding the inflowing water (98).

4. Power plant unit according to claim 3, wherein the damming device (70) has at least one guide element (72a, 72b) arranged on an upper side (11) of the power plant unit (10) opposite the body of water (90) and with which inflowing water (98) can be led to the barrier (71).

5. Power plant unit according to one of the preceding claims, wherein the damming device (70) on a body of water (90) opposite top (11) of the power plant unit (10) arranged ramp (73a, 73b).

6. Power plant unit according to one of the preceding claims, wherein the feed device (42a, 42b) has a feed pipe (43a, 43b) which runs from an opening (74a, 74b) in the damming device (70) to the at least one hydroelectric power machine (40 ) runs.

7. Power plant unit according to one of the preceding claims, wherein the at least one hydroelectric power machine (40) is a Kaplan turbine or a Kaplan-like turbine, for example a VLH (Very Low Head) turbine.

8. Power plant unit according to claim 7, wherein downstream of the turbine (40).

Pipe (44) is arranged, with which the water bine can be carried away after passing through the turbine.

9. Power plant unit according to claim 7 or 8, wherein a suction pipe (44) is arranged downstream of the turbine (40), which opens below the water level (96, 97) to the body of water (90).

10. Power plant unit according to one of the preceding claims, wherein a device is provided with which a floating body (20') can be moved in relation to the storage device (70).

11. Power plant unit according to one of the preceding claims, wherein a device is provided with which a floating body (20') can be moved in relation to the damming device (70).

12. Power plant unit according to one of the preceding claims, wherein a first device (45) is provided, with which the water power machine (40) alternately with a first feed pipe (43a) and a second feed pipe (43b) is fluidly connected.

13. Power plant unit according to any one of the preceding claims, wherein a second

Device (46) is provided, with which the water power machine (40) alternately with a first tube (44a) arranged downstream of the turbine and a second tube (44b) arranged downstream of the turbine can be connected fluidically ver.

14. A method for generating electrical energy from a directed water flow (91) on the surface of a body of water (90), comprising providing a damming device (70) carried by at least one floating body (20), which in relation to a surface flow (91) a body of water (90) is fixed in place, with inflowing (98) water being guided upwards by the damming device in relation to a local water level (96) of the body of water and being dammed to form a standing water wave (94a, 94b); diverting water from the standing water wave 94a, 94b) into a water power machine; the generation of electrical energy with a power generator (41) driven by the water power machine (40).

15. The method according to claim 10, wherein the method is carried out with a power plant unit (1) according to any one of claims 1 to 9.