DE20206234U1 - Floatable wind turbine - Google Patents

Description

93 148 v5/abr

Floating wind turbine

Field of the invention

The invention relates to a floating wind turbine that can be anchored near the coast and generates energy as cost-effectively as possible in poorly developed or undeveloped areas. This energy can be used, for example, to operate a seawater desalination plant.

State of the art

There are various systems for seawater desalination, all of which have a relatively high energy requirement. Almost all seawater desalination plants are operated with diesel generators, which in turn drive the corresponding generators to produce the required electrical energy. The operation of conventional seawater desalination plants therefore places a burden on the environment and climate through exhaust emissions and the resulting cooling heat. In addition, it is difficult to build such plants in coastal areas that are difficult to access and do not have the appropriate infrastructure.

The same problems of difficult installation occur with conventional wind turbines, which, when large, are extremely difficult to transport and often cannot be transported to the locations most suitable for generating wind energy.

Description of the invention

The invention is based on the object of proposing a decentralized energy supply facility that can also be installed in coastal areas that are difficult to access and can be coupled with seawater desalination.

This object is achieved by a floating wind turbine having the features of claim 1.

Advantageous embodiments of the invention follow from the remaining claims.

The invention is based on the idea of proposing a floating wind turbine that has a buoyancy body from which a rotor unit and an underwater part extend on opposite sides to stabilize the wind turbine. The rotor unit comprises at least one Gelhard rotor.

A Gelhard rotor, as will be shown later in Fig. 1, is essentially the same in structure as a Darrieus H rotor, the advantages of which are that the rotor rotates around a vertical axis, which means that the tilting moments that occur with horizontal axis systems are not present. Gelhard rotors are inexpensive to manufacture because a simple mast construction is possible, no additional wind tracking is required, as is the case with horizontal axis systems, and the individual rotor blades have a simple wing shape. In addition, the floating wind turbine with Gelhard rotors is also almost maintenance-free, as a very long service life can be achieved, particularly due to the uniform rotation. In addition, the wind turbine is self-starting and has very low operating costs. Another advantage is that the

A floating wind turbine with at least one Gelhard rotor is quiet because no unpleasant, beating rotor noises (so-called shadows) occur.

A final advantage associated with the use of at least one Gelhard rotor is that the wind turbine starts up even at very low wind speeds of around 2.25 m/s (wind force 2).

The floating wind turbine is transported by water to the desired installation location and anchored to the waterbed using suitable anchors.

Preferred embodiments of the invention follow from the remaining claims. According to a preferred embodiment of the invention, a rotating body designed as a gyroscope is provided in the underwater part of the floating wind turbine, which can be driven in the direction of rotation. This design has several advantages. Firstly, an appropriate weight must be provided in the underwater part in order to generate the stabilizing and righting moment of the wind turbine when waves hit. For this purpose, a high weight must be provided in the area of the underwater part, similar to a keel in boat building. By having a rotating body that can be driven as a gyroscope in the underwater part, the weight required to stabilize the wind turbine is provided and at the same time this weight is also used to store kinetic energy. A rotating body in the underwater part, which can have a diameter of about 2m and a height of about 1m, for example, can store a considerable amount of kinetic energy when rotating quickly and thus buffer climatically induced changes in the available wind energy.

Preferably, the rotating body has poles on its circumferential surface and acts together with a coil arrangement on the surrounding inner wall of the underwater part as a multi-pole generator. In addition to the two functions mentioned above of providing sufficient weight to stabilize the wind turbine and storing kinetic energy, this solution provides a third function of the rotating body. The rotating body acts as a multi-pole generator for generating electrical energy.

According to a preferred embodiment, the underwater part can be tightly sealed and evacuated from the buoyancy body. The tight sealing of the underwater part is done on the one hand with regard to the operational safety of the entire system, which, when designed as a multi-chamber system, can still provide an undamaged chamber with appropriate buoyancy even if the buoyancy body is damaged. On the other hand, by evacuating the underwater part in which the rotating body is located, the frictional resistance during rotation of the rotating body designed as a gyroscope can be minimized in accordance with the degree of evacuation, which can reduce corresponding losses.

According to a preferred embodiment of the invention, the rotor unit comprises two Gelhard rotors, the rotor shafts of which are arranged coaxially to one another and which rotate in opposite directions when exposed to wind. This special design of two counter-rotating rotors means that no lateral torque is generated, since the torques of the two rotors cancel each other out. If the torques of the rotors cancel each other out, the anchoring of the floating wind turbine is possible even if the seabed is not of optimal quality, since the anchors do not generate any torques.

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no longer have to absorb, but primarily serve to fix the location.

According to a preferred embodiment of the invention, each rotor shaft drives a gear pump, with which hydraulic fluid can be pumped into an associated hydraulic circuit. In other words, each rotor shaft acts on a gear pump and each gear pump has an independent hydraulic circuit. When two Gelhard rotors are used, two hydraulic circuits are thus present, with the hydraulic fluid being pumped by a gear pump connected to a rotor shaft. Gear pumps are particularly characterized by their wear-free and maintenance-free operation.

Preferably, each hydraulic circuit includes a gear motor, the gear movement of which can drive the rotating body belonging to the multi-pole generator. The generator is thus driven hydraulically by the two rotors rather than mechanically. The advantage is that this measure enables a gear ratio to be achieved. The speed of the coaxially arranged rotor shafts is around 70 - 80 rpm with a normal drive - a speed that is too low to drive the generator. In order to achieve a gear ratio, a separate hydraulic circuit is used for the entire power transmission of the two rotors and the gear pumps are selected to be so much larger in terms of volume than the gear motors as the gear ratio required for the generator on the drive side requires. In this way, wear-free and maintenance-free power transmission can be achieved.

According to a preferred embodiment, an intermediate gear and/or a freewheel is provided between each gear motor and the rotating body acting as a generator. The freewheel is required so that the

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Wind turbine does not brake the rotating body when there is no wind or can bring it to a standstill when there is no wind for a long time. An intermediate gearbox can be provided in order to be able to constructively set the desired gear ratios to the optimal values. The gear motors can, for example, act on the rotating body via an intermediate planetary gearbox.

According to a preferred embodiment of the invention, a bypass line around the gear motor is provided in each hydraulic circuit, as well as a three-way valve with which the flow distribution between the bypass line and the flow line to the gear motor can be adjusted. This measure makes it easy to disconnect and reconnect the power transmission between the rotor shafts and the rotating body of the generator and, if, according to a further preferred embodiment, the three-way valve in each hydraulic circuit works together with a speed limiter that is mechanically or informationally coupled to the rotating body, the maximum speed to be set can also be controlled. By having a speed controller control the hydraulic three-way valve accordingly when the maximum speed is exceeded, a safe, reliable and, above all, cost-effective control of the speed limit can be achieved.

The floating wind turbine preferably includes a seawater desalination plant that is located in the area of the buoyancy body and can be operated using the wind energy generated. The environmentally friendly electricity generated by the wind turbine thus operates an integrated seawater desalination plant, with which seawater desalination and thus decentralized drinking water supply can be achieved cost-effectively. The operation of the corresponding pumps for sucking in seawater and pumping drinking water can also be operated using the electrical energy generated.

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It has proven particularly advantageous if the entire floating wind turbine also includes a device for buffering the electrical energy. Since the rotating body in the underwater part already buffers the kinetic energy and provides as even a release of electrical energy as possible via the generator, the seawater desalination plant can be regulated as needed by separately buffering the electrical energy and longer periods of calm wind can be bridged by providing additional buffering for electrical energy. Various systems such as batteries can be used to buffer the electrical energy, or an additional system for electrolyzing water, a device for storing hydrogen and a fuel cell can be provided. Alternatively, however, other systems known in technology for storing electrical energy can also be used.

Short description of the drawings

Fig. 1 shows a schematic view of the floating wind turbine with two Gelhard rotors arranged one above the other;

Fig. 2a shows a top view of the lower rotor, i.e. the rotor located closer to the water surface,

Fig. 2b shows a top view of the upper rotor, and

Fig. 3 schematically explains the power transmission between the rotor shafts and the multi-pole generator.

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Ways to implement the invention

In the following description, the same components will be designated by the same reference numbers.

Fig. 1 shows the floating wind turbine according to the invention. The wind turbine, generally designated by reference number 10, floats in a body of water, the water surface of which is shown schematically in Fig. 1. The wind turbine 10 consists of a buoyancy body 12 which is rotationally symmetrical and, in addition to an essentially cylindrical floating part 12a, has a truncated cone-shaped attachment part which is firmly connected to the floating part, which together form a buoyancy housing in which the units of the overall system 10, which are explained in more detail later, are housed. The truncated cone shape above the water surface serves to offer only a small surface area for both the wind and the waves to attack.

On one side of the buoyancy body 12, an underwater part 14 is firmly connected to it, which acts as a keel and stabilizes the entire wind turbine 10, i.e. it keeps it steady even in heavy waves and returns the entire wind turbine to a vertical position if it tilts undesirably. One or more anchoring elements 16 are attached to the underwater part 14, with which the wind turbine is anchored to the bottom of the water (not shown) using anchors or similar.

On the side of the buoyancy body opposite the underwater part 14, the rotor unit 18 is provided, which consists of two Gelhard rotors 18a and 18b arranged one above the other. The two rotors 18a and 18b can each be rotated about a vertical axis 20 and are arranged coaxially to one another, as will become clearer later from the explanation of Figs. 2a and 2b.

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The buoyancy body 12 is provided with an access hatch 22 which, similar to submarines, can be completely closed and ensures absolute tightness. The hatch is arranged as high up as possible, i.e. directly next to the support tube 24 for the rotors 18a, 18b, and is additionally surrounded by a grid 26 which serves as protection against wave impact. Starting from the hatch there are ladders leading into the buoyancy body 12 and the underwater part 14. The underwater part could be provided with a diameter of approximately 1.0 m in the area 14a, which is the connecting pipe from the buoyancy body 12 to the extended underwater part 14b, which accommodates the rotating body explained later, so that a person can easily reach the underwater part using a ladder.

The underwater part 14 of the wind turbine 10 consists of a connecting pipe 14a and a rotationally symmetrical underwater housing 14b in which there is a rotating body 28 which is designed as a gyroscope and, as will be explained later, is set in rotation by the rotation of the rotors 18a, 18b. In the present embodiment, the rotating body 28 is provided with magnetic poles 30 which interact with a coil 32 arranged on the housing 14b and together form a multi-pole generator which generates electrical energy when the rotating body 28 rotates.

In Fig. 2a and 2b, the two rotors 18a and 18b are shown in section. This is a horizontal section plane when using the floating wind turbine on calm water. As can be seen from Fig. 2a and 2b, three rotor blades 34 with a streamlined profile are rigidly connected to a rod assembly 36, which in turn is rigidly connected to a hollow axle 38a for the rotor 18a or 38b for the rotor 18b. The outer diameter of the hollow shaft 38b and the inner diameter of the hollow shaft 38a are coordinated so that the

Hollow shaft 38b of the rotor 18b can be arranged inside the hollow shaft 38a of the rotor 18a. When exposed to wind from a certain wind direction, the profiling of the rotor blades causes the entire rotor, consisting of rotor blades, rods and hollow shaft, to rotate. Since, as is clear from a comparison of Fig. 2a and 2b, the arrangement of the profiled rotor blades is different for the two rotors, this also results in the two rotors 18a and 18b rotating in opposite directions. This in turn means that the torques generated on the rotor shafts 38a and 38b during operation of the wind turbine are in opposite directions to one another, cancel each other out and therefore do not need to be absorbed. In wind turbines that are operated stationary on land, the torques that occur can be easily absorbed via the foundation of the wind turbine. In the case of the floating wind turbine according to the invention, however, such a torque must be absorbed via the anchorage 16 between the underwater part and the bottom of the water, which is why this is no longer possible in larger-dimensioned systems or can only be achieved with considerable difficulty and therefore the special design with two rotors rotating in opposite directions to each other has particular advantages.

In the area of the buoyancy body, there can be a seawater desalination plant, which, in addition to the fittings and instruments required for this, also accommodates the necessary control, regulating and monitoring instruments. In the underwater part, in addition to the already described rotating body 28, which can be used as part of a multi-pole generator, a storage device for electrical energy in the form of hydrogen electrolysis as well as fuel cells, high-pressure bottles for storing hydrogen or buffer batteries for emergency power can be conveniently accommodated.

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A tightly sealable hatch can be provided in the area of the connection 14a between the buoyancy body and the underwater part 14. This hatch divides the unit consisting of the buoyancy body 12 and the underwater part 14 into two chambers so that in the event of possible damage to the remaining chamber there is sufficient residual buoyancy. The tightly sealable hatch also makes it possible to evacuate the underwater part so that the rotating body 28 does not have to overcome air friction during its rotation and thus the energy loss is minimized.

Fig. 3 shows the function of the entire system in a highly schematic manner according to the embodiment described here. The individual components are both shown schematically and arranged on the plane of the drawing at a location which is suitable for easier representation of the interaction between the individual components, but does not represent the correct geometric position of the individual components. For example, as described above, the seawater desalination system is preferably arranged in the buoyancy body 12, while in the present example it is shown on the plane of the drawing in Fig. 3 below the rotating body.

Turning to Fig. 3, the hollow shafts 38a and 38b belonging to the two rotors 18a and 18b are shown schematically. The hollow shaft of the rotor 18b, i.e. the axis 38b, is directly connected to a first gear pump 40 in a rotationally rigid manner and drives the first gear pump 40 through its rotation. The hollow shaft 38a of the rotor 18a is also connected to the second gear pump 42 in a rotationally rigid manner. In the present example of the hollow shaft 38a, it was shown schematically that the hollow shafts do not have to be directly connected to the gear pumps, but that an intermediate gear can also be present, as shown by

the reference number 44 is indicated in relation to the external hollow shaft 38a.

A separate hydraulic circuit is assigned to both the first gear pump 40 and the second gear pump 42. However, since the flow in both hydraulic circuits is the same, the separate hydraulic circuits can be discussed together below. The hydraulic fluid in the hydraulic circuits is pumped through the pipes via the gear pumps 40 and 42 and reaches a three-way valve 46 or 48 in the direction of arrow A, via which the hydraulic fluid can be divided into the partial flows Bl and B2. The three-way valve 46 or 48 can of course be operated in such a way that hydraulic fluid only flows through path Bl or B2 or also through both paths simultaneously in predetermined ratios. While the path Bl flows through the additional gear pump 5 0 or 52 assigned to each hydraulic circuit, which acts as a gear motor and is set in rotation by the flow of the hydraulic fluid, the paths Bl serve as a bypass around the gear motors 5 0 and 52. After the partial lines Bl and B2 have been reunited, the hydraulic fluid flows back to the first gear pumps 4 0 and 42 via the return path C.

The gear motors 5 0 and 52 are set in rotation by the flowing hydraulic fluid and act on the rotating body 28, which is arranged in the underwater part and can be set in rotation in the form of a gyroscope. The transfer of the kinetic energy between the gear pumps 5 0 and 52 and the rotating body 2 8 can take place via intermediate gears 54 and 56, which are preferably each provided with a freewheel so that at low wind speeds and, as a result, a low delivery capacity of the gear pumps 40 and 42 and a low rotational speed of the gear motors 5 0 and

52, the rotating body 28 cannot be braked or even brought to a standstill. On the other hand, a precaution has also been taken to ensure that the rotating body 28 cannot reach too high a speed. This is implemented in the form of a speed limiter 58, which is rigidly connected to the rotating body 28 and can act in a manner familiar to those skilled in the art, for example via a centrifugal mechanism. The speed limiter 58 is either directly mechanically connected to the three-way valves 46 and 48 via the connections 60, or is in information communication with them. If the speed of the rotating body 28 becomes too high according to the specification, the three-way valves 46 and 48 open the bypass path B2, so that less hydraulic fluid is available to drive the gear motors 50 and 52.

As already explained above with reference to Fig. 1, the rotating body 28 is provided with magnetic poles 30 which interact with a coil 32 and turn the rotating body 28 and the surrounding coil arrangement 32 into a multi-pole generator which generates electrical energy. The electrical energy generated is first preferably fed to an energy buffering device 62 which can, for example, use the electrical energy generated by the multi-pole generator in a first sub-unit 64 for hydrogen electrolysis. The hydrogen generated can be stored in a further sub-unit 66, e.g. in the form of high-pressure bottles, and made available again via a power generator 68, e.g. in the form of a fuel cell, in order to operate a seawater desalination plant 70 to which seawater is fed in the direction of arrow E and from which drinking water is pumped out in the direction of arrow F and conveyed via a pipe to the nearby shore. The seawater desalination plant can operate according to any process known in the art today, but preferably the seawater desalination plant 70 operates according to the reverse osmosis process.

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Through the interaction of the buffering of kinetic energy in the rotating body 2 8 and the buffering of electrical energy in the energy buffering device, even longer periods of calm wind caused by climate change can be bridged and the energy required to operate an energy-intensive seawater desalination plant can still be provided at low cost.

Due to the use of Gelhard rotors, the floating wind turbine is not only easy to operate and maintenance-free, but can also achieve very low kW-hour prices, which are max. EUR 0.05 for systems up to 10 kW and around EUR 0.04 for systems over 10 kW. At the same time, the burden on the environment is reduced and, when such seawater desalination plants are used to meet drinking water requirements, the increase in water in the seas caused by climate change is compensated.

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Claims (13)

1. Floating wind turbine comprising: - a buoyancy body ( 12 ) from which on opposite sides - a rotor unit ( 18 ); and - an underwater part ( 14 ); - the rotor unit ( 18 ) comprises at least one Gelhard rotor ( 18 a, 18 b). 2. Floatable wind power plant according to claim 1, characterized in that a rotating body ( 28 ) designed as a gyroscope is provided in the underwater part ( 14 ), which can be driven in the direction of rotation. 3. Floatable wind power plant according to claim 2, characterized in that the rotating body ( 28 ) has magnetic poles ( 30 ) on its peripheral surface and acts as a multi-pole generator together with a coil arrangement ( 32 ) on the surrounding inner wall of the underwater part ( 14 ). 4. Floatable wind turbine according to one of the preceding claims, characterized in that the underwater part ( 14 ) can be tightly closed off and evacuated relative to the buoyancy body ( 12 ). 5. Floatable wind turbine according to one of the preceding claims, characterized in that the rotor unit ( 18 ) comprises two Gelhard rotors ( 18a , 18b ), the rotor shafts ( 38a , 38b ) of which are arranged coaxially to one another and rotate in opposite directions when exposed to wind. 6. Floating wind power plant according to claim 5, characterized in that each rotor shaft ( 38 a, 38 b) drives a gear pump ( 40 , 42 ) with which hydraulic fluid can be pumped in an associated hydraulic circuit. 7. Floating wind turbine according to claim 6, characterized in that each hydraulic circuit comprises a gear motor ( 50 , 52 ), by whose gear movement the rotating body ( 28 ) can be driven. 8. A floating wind turbine according to claim 7, further comprising an intermediate gear ( 54 , 56 ) and/or a freewheel between each gear motor ( 50 , 52 ) and the rotating body ( 28 ). 9. Floating wind turbine according to claim 7 or 8, further comprising in each hydraulic circuit a bypass line (B2) around the gear motor ( 50 , 52 ) and a three-way valve ( 46 , 48 ) with which the flow distribution between the bypass line and line (B1) to the gear motor ( 50 , 52 ) can be adjusted. 10. Floatable wind power plant according to claim 9, characterized in that the three-way valve ( 46 , 48 ) in each hydraulic circuit interacts with a speed limiter ( 58 ) which is mechanically or informationally coupled to the rotating body ( 28 ). 11. Floating wind turbine according to one of the preceding claims, further comprising a seawater desalination plant which can be operated via the wind energy generated. 12. Floatable wind turbine according to claim 3 or one of claims 4 to 11, as long as it is dependent on claim 3, further comprising a device ( 62 ) for buffering the electrical energy. 13. Floating wind turbine according to claim 12, characterized in that the device ( 62 ) for buffering the electrical energy comprises: - an electrolysis plant ( 64 ), - a hydrogen storage facility ( 66 ); and - a fuel cell ( 68 ).