Wind turbine and wind power plant

Abstract

A counter-rotating wind turbine (10) is disclosed comprising a first turbine rotor (36) mounted on a first turbine shaft (37) rotatable about an axis of rotation (A) and a second turbine rotor (47) mounted on a second turbine shaft (48) rotatable about an axis of rotation (A). And the second turbine shaft (48) is rotatable in opposite directions about the same axis of rotation (A). The first turbine rotor (36) comprises at least one first turbine blade (38) extending in an outward direction from the first turbine shaft (37), and the second turbine rotor (47) comprises at least one second turbine blade (49) extending in an outward direction from the second turbine shaft (48). At least one of the first turbine blades (38) also forms a first blade angle (40) with respect to the first turbine shaft (37) and at least one of the second turbine blades (49) forms a second blade angle (51) with respect to the second turbine shaft (48), the first blade angle (40) and the second blade angle (51) being both acute angles during operation of the wind turbine (10).

Description

Technical Field

[0001] The present invention relates to a counter-rotating wind turbine, which wind turbine comprises at least: a first turbine rotor and a second turbine rotor mounted in counter-rotation; and to a wind power generation device comprising a counter-rotating wind turbine, which counter-rotating wind turbine comprises at least: a first turbine rotor and a second turbine rotor mounted in counter-rotation. Background Art

[0002] Wind power is playing an increasingly important role in the ongoing energy transition to renewable energy sources. It is estimated that the global cumulative installed capacity of onshore wind power will more than triple by 2030 and could grow sevenfold by 2050, with further substantial global growth in installed wind power capacity expected by 2050.

[0003] There are two main wind turbine technologies today that are categorized by the orientation of the wind turbine's axis of rotation. Three-bladed horizontal axis wind turbines (HAWTs) with blades located upwind of a tower generate the vast majority of wind power generated in the world today. These turbines have a main rotor shaft and a generator at the top of a tower and are aimed into the wind. The generator is placed on top of the shaft in a nacelle. The technology involved in this type of wind turbine has matured, and all horizontal turbines produced and installed today have a similar design. Over the past few years, both the size and installed capacity of HAWTs have increased, and now range from 1 MW to 14 MW per turbine. HAWTs have traditionally been installed onshore, but are now also beginning to be installed on the seafloor in shallow waters.

[0004] A vertical axis wind turbine (VAWT) has an axis of rotation perpendicular to the wind direction and is typically mounted with the axis of rotation vertical relative to the ground. Thus, this is a type of wind turbine in which the main rotor shaft is arranged transverse to the wind, and the main components can be located at the base of the turbine. This arrangement allows the generator to be located close to the ground, where the center of gravity is low, allowing for easy access for maintenance and repair. VAWTs do not need to be pointed into the wind, which eliminates the need for wind sensing and orientation mechanisms. However, VAWTs have not received the same attention and investment as HAWTs, and today account for less than 0.1% of wind power generation capacity.

[0005] There are several drawbacks to the existing technology associated with VAWTs, which is why VAWTs have received very little attention to date. Firstly, the efficiency of the conventional Savonius VAWT turbine is lower relative to the HAWT, as it is primarily a drag-operated turbine, and the downwind blades do not contribute to power generation. The smaller Darius turbines are also subject to vibration from the torque applied to the mast, resulting in increased wear and maintenance requirements. Finally, and perhaps most importantly, VAWTs have received far less investment in research and development than HAWTs, and are therefore a less mature technology.

[0006] Generally speaking, the problem with existing wind turbines is the gear system that is subject to large and varying forces. Therefore, the gear system must be designed to withstand large and varying forces over time, which is expensive. Wind turbines still require a lot of maintenance and monitoring to prevent and avoid complete gear failure.

[0007] Wind turbines are often installed in locations with harsh climatic conditions, so the design of the wind turbine must compensate for the effects of high winds and also compensate for the effects of waves on wind turbines installed offshore. Furthermore, wind conditions can vary greatly depending on how far from the ground or water surface the wind turbine is installed.

[0008] Purpose of the Invention

[0009] Therefore, it is an object of the present invention to develop a wind turbine in which at least one and preferably some or all of the above mentioned problems are alleviated.

[0010] A further object of the present invention is to develop a wind turbine which can be scaled up to much larger sizes than wind turbines installed today.

[0011] A further object of the present invention is to provide a wind turbine which is capable of generating substantially more power than wind turbines known today are capable of generating.

[0012] A further object of the present invention is to develop a wind turbine with a generator that does not require a gear system.

[0013] A further object of the present invention is to provide a wind turbine, wherein the manufacturing, maintenance and monitoring costs of the gear system of the wind turbine are reduced. Summary of the invention

[0014] These objects are achieved with a counter-rotating wind turbine as defined in claim 1 and a wind power plant as defined in claim 27. Further embodiments of the invention are defined in the dependent claims.

[0015] Therefore, a counter-rotating wind turbine is provided, the wind turbine comprising at least: a first turbine rotor mounted on a first turbine shaft and a second turbine rotor mounted on a second turbine shaft, wherein the first turbine shaft is rotatable about a rotation axis (A) and the second turbine shaft is rotatable in opposite directions about the same rotation axis (A), wherein the first turbine rotor comprises at least one first turbine blade extending in an outward direction from the first turbine shaft, and wherein the second turbine rotor comprises at least one second turbine blade extending in an outward direction from the second turbine shaft.

[0016] At least one first turbine blade may form a first blade angle relative to the first turbine axis, and at least one second turbine blade may form a second blade angle relative to the second turbine axis, the first blade angle and the second blade angle being both acute angles, at least when the wind turbine is in operation, but also possibly when it is not in operation.

[0017] Thus, preferably, at least one first turbine blade has a first longitudinal axis forming a first blade angle with the axis of rotation (A), such that when the at least one first turbine blade rotates about the axis of rotation (A), the first longitudinal axis forms a conical shape, and / or at least one second turbine blade preferably has a second longitudinal axis forming a second blade angle with the axis of rotation (A), such that when the at least one second turbine blade rotates about the axis of rotation (A), the second longitudinal axis forms a conical shape. Thus, when the at least one first turbine blade and the at least one second turbine blade rotate about the axis of rotation (A), the at least one first turbine blade and the at least one second turbine blade preferably sweep a respective conical area.

[0018] Thus, the at least one first turbine blade preferably sweeps a conical area and / or in counter-rotating wind turbine operation the at least one second turbine blade preferably sweeps a conical area.

[0019] When the wind turbine is in operation, the rotation axis (A) preferably forms an acute angle with the horizontal plane. Thus, at least when the wind turbine is in operation, the wind turbine has a rotation axis that is inclined relative to the wind direction.

[0020] The first turbine rotor sweeps a first swept area when in operation and the second turbine rotor sweeps a second swept area when in operation, and preferably the first turbine rotor and the second turbine rotor are configured such that when the axis of rotation (A) is vertical, the first swept area and the second swept area do not substantially overlap.

[0021] The second turbine shaft is preferably rotatably mounted within the first turbine shaft such that the first turbine shaft and the second turbine shaft are coaxial.

[0022] The at least one first turbine blade is mounted or attached to the first turbine shaft by means of a first connection means, and wherein the at least one second turbine blade is mounted to the second turbine shaft by means of a second connection means.

[0023] The first longitudinal axis of at least one first turbine blade preferably extends from an outer tip of the at least one first turbine blade to a center point of the first connecting device, and / or the second longitudinal axis of at least one second turbine blade preferably extends from an outer tip of the at least one second turbine blade to a center point of the second connecting device.

[0024] The first connection means is preferably configured to allow adjustment of the first blade angle and / or the second connection means is preferably configured to allow adjustment of the second blade angle.

[0025] The first blade angle and the second blade angle can preferably be adjusted independently of one another or separately.

[0026] The first connection means is preferably configured to allow adjustment of the pitch of the at least one first turbine blade and / or the second connection means is preferably configured to allow adjustment of the pitch of the at least one first turbine blade.

[0027] The first blade angle and the second blade angle are preferably adjusted independently of each other, for example, such that after the adjustment, the first blade angle and the second blade angle are equal.

[0028] The first blade angle may preferably be adjusted such that the first blade angle is less than 70 degrees and greater than 20 degrees, and / or the second blade angle may preferably be adjusted such that the second blade angle is less than 70 degrees and greater than 20 degrees.

[0029] More preferably, the first blade angle may be preferably adjusted such that the first blade angle is less than 50 degrees and greater than 40 degrees, and / or the second blade angle may be preferably adjusted such that the second blade angle is less than 50 degrees and greater than 40 degrees.

[0030] The at least one first turbine blade is preferably airfoil-shaped and / or the at least one second turbine blade is preferably airfoil-shaped.

[0031] The first turbine rotor preferably comprises at least one first support arm mounted to the first turbine blade and to the first turbine shaft, and the second turbine rotor preferably comprises at least one second support arm mounted to the second turbine blade and to the second turbine shaft.

[0032] At least one first support arm is preferably mounted to the first turbine blade and to the upper side of the first turbine shaft, and / or at least one second support arm is preferably mounted to the second turbine blade and to the upper side of the second turbine shaft. Thus, the first turbine shaft preferably extends to enable the first support arm to be mounted to the first turbine shaft.

[0033] The length of the at least one first support arm is preferably adjustable so that the first blade angle, ie the angle between the at least one first turbine blade and the rotation axis, can be adjusted. For example, the at least one first support arm may comprise two or more telescopic sections to adjust the length of the at least one first support arm.

[0034] The length of the at least one second support arm is preferably adjustable so that the second blade angle, ie the angle between the at least one second turbine blade and the rotation axis, can be adjusted. For example, the at least one second support arm may comprise two or more telescopic sections to adjust the length of the at least one second support arm.

[0035] The swept area of ​​the first turbine rotor is preferably 0% to 20% greater than the swept area of ​​the second turbine rotor.

[0036] The at least one first support arm is preferably airfoil-shaped and / or the at least one second support arm is preferably airfoil-shaped.

[0037] At least one first support arm and / or at least one second support arm is provided with a motion damper arrangement.The motion damper arrangement is preferably configured to be able to dampen / reduce shocks and / or vibrations.

[0038] The first support arm preferably forms an angle with the at least one first turbine blade of less than 135 degrees and greater than 45 degrees, and / or the second support arm preferably forms an angle with the at least one second turbine blade of less than 135 degrees and greater than 45 degrees.

[0039] More preferably, the first support arm preferably forms an angle of less than 120 degrees and more than 70 degrees with the at least one first turbine blade, and / or the second support arm preferably forms an angle of less than 120 degrees and more than 70 degrees with the at least one second turbine blade.

[0040] The at least one first turbine blade is preferably provided with a first airfoil mounted to a tip portion of the at least one first turbine blade and / or the at least one second turbine blade is preferably provided with a second airfoil mounted to a tip portion of the at least one second turbine blade.

[0041] The first airfoil is preferably arranged substantially perpendicular to the longitudinal axis of the at least one first turbine blade and / or the second airfoil is preferably arranged substantially perpendicular to the longitudinal axis of the at least one second turbine blade.

[0042] The first airfoil is installed with its concave side facing the first turbine blade or with its concave side facing away from the first turbine blade. Similarly, the second airfoil is installed with its concave side facing the second turbine blade or with its concave side facing away from the second turbine blade.

[0043] The first airfoil is preferably adjustably mounted to at least one first turbine blade and / or the second airfoil is preferably adjustably mounted to at least one second turbine blade.

[0044] The first fin is preferably airfoil-shaped and / or the second fin is preferably airfoil-shaped.

[0045] The length of the at least one first turbine blade is preferably greater than the diameter of the first turbine shaft and / or the length of the at least one second turbine blade is preferably greater than the diameter of the second turbine shaft.

[0046] The length of the at least one first turbine blade is preferably substantially greater than the diameter of the first turbine shaft and / or the length of the at least one second turbine blade is preferably substantially greater than the diameter of the second turbine shaft.

[0047] The at least one first turbine blade preferably comprises a plurality of first blade sections connected or attached to one another and / or the at least one second turbine blade preferably comprises a plurality of second blade sections connected or attached to one another.

[0048] Two adjacent first blade segments are preferably attached to each other at an angle so that the two adjacent first blade segments form a non-linear first turbine blade, and / or two adjacent second blade segments are preferably attached to each other at an angle so that the two adjacent second blade segments form a non-linear second turbine blade.

[0049] At least one pair of adjacent first blade segments are preferably attached to each other in an articulated manner, and / or at least one pair of two adjacent second blade segments are preferably attached to each other in an articulated manner.

[0050] The at least one first blade segment is preferably attached to the at least one first support arm and / or the at least one second blade segment is preferably attached to the at least one second support arm.

[0051] At least a portion of at least one first turbine blade may be bent upward or downward relative to the direction of the rotation axis (A), and / or at least a portion of at least one second turbine blade may be bent upward or downward relative to the direction of the rotation axis (A).

[0052] At least a portion of at least one first turbine blade may be curved forwards or backwards relative to the rotation direction of the first turbine rotor and / or at least a portion of at least one second turbine blade may be curved forwards or backwards relative to the rotation direction of the second turbine rotor.

[0053] The at least one first turbine blade may be bent at least partially in a circumferential direction around the first turbine axis and / or the at least one second turbine blade may be bent at least partially in a circumferential direction around the second turbine axis.

[0054] A wind power generation device is also provided, which includes a counter-rotating wind turbine, which does not include any of the above additional features, includes one of the above additional features, includes some of the above additional features, or includes all of the above additional features.

[0055] The wind power plant preferably comprises a generator driven by counter-rotating wind turbines.

[0056] The generator is preferably a synchronous generator.

[0057] More preferably, the generator is preferably a permanent magnet synchronous generator. For example, the permanent magnet synchronous generator may include a neodymium iron boron (NeodyniumIronBor) magnet or a ferrite magnet.

[0058] The armature winding preferably comprises a high voltage cable.

[0059] The first turbine shaft is preferably mounted to a stator portion of the generator and the second turbine shaft is preferably mounted to a rotor portion of the generator.

[0060] The stator portion may be defined as the portion of the generator including the armature windings.

[0061] The stator part on the rotating first turbine shaft preferably comprises a commutator so that direct current can be transmitted via the rotating contacts. For example, the rotating contacts may comprise slip rings or liquid metal contacts.

[0062] The generator is preferably dimensioned to withstand a load of 1 to 5 times the rated power, preferably 2 to 3 times the rated power. This will allow operational control of the first wind turbine and the second wind turbine even in stormy weather conditions.

[0063] The rectifier is preferably configured to perform active rectification or to perform rectification using a diode.

[0064] The absorption of the effects of the first wind turbine and / or the second wind turbine is preferably controlled by controlling the rotational speed of the first wind turbine and / or the second wind turbine, i.e. stall controlled by the torque of the generator, which torque can be controlled by selecting the voltage level on the DC side of the rectifier for active rectification or passive rectification.

[0065] The stator part preferably comprises a first stator part and a second stator part, wherein the first stator part is preferably non-rotatable and the second stator part is preferably rotatable.

[0066] A non-rotatable first stator part is mounted to a tower section of a wind power plant and a rotatable second stator part is mounted to a first turbine shaft.

[0067] The stationary first stator part is preferably configured such that it is possible to use the first stator part as an electric machine, via which torque can be applied to the second turbine shaft.

[0068] The counter-rotating turbines are preferably configured so that, during operation, the axis of rotation (A) is inclined relative to the horizontal.

[0069] The wind power generation equipment is preferably configured so that: when in operation, at least one first turbine blade forms a first blade angle with the rotation axis (A), the first blade angle being substantially equal to the inclination of the rotation axis (A) relative to the horizontal plane, and / or at least one second turbine blade forms a second blade angle with the rotation axis (A), the second blade angle being substantially equal to the inclination of the rotation axis (A) relative to the horizontal plane.

[0070] The at least one first turbine blade may be arranged such that when the first blade tip portion is in an uppermost position of the rotational path of the first blade tip portion, the at least one first turbine blade is substantially vertical.

[0071] The at least one second turbine blade may be arranged such that when the second blade tip portion is in a highest position of the rotational path of the second blade tip portion, the at least one second turbine rotor is substantially vertical.

[0072] The wind power plant may be an onshore wind power plant.

[0073] The wind power plant may also be a floating wind power plant, ie a wind power plant adapted to be arranged to float in a body of water.

[0074] The wind power plant preferably comprises at least one hydrofoil arranged such that the hydrofoil is below the water surface of the body of water, the at least one hydrofoil being adjustable when there is a current in the body of water to provide a desired moment for the wind power plant.

[0075] The tower of the wind power plant is preferably mounted to the anchoring system.

[0076] The anchoring system is preferably configured to withstand any torque produced by the generator.

[0077] The generator may be configured such that the generator may be used as a motor by which a torque is applied between the first turbine shaft and the second turbine shaft. This will allow the generator to be used as a motor to start the rotation of the first turbine rotor and the second turbine rotor.

[0078] The tower preferably comprises at least one buoyancy unit and / or ballast unit.

[0079] The tower is preferably made of steel, aluminium, wood or a combination of these materials.

[0080] The buoyancy unit and / or the ballast unit and / or the generator housing are preferably made of steel, or concrete, or a combination of steel and concrete.

[0081] The first turbine shaft and / or the second turbine shaft are preferably made of steel, aluminium, wood or a combination of these materials.

[0082] The at least one first turbine blade and / or the second turbine blade and / or the first turbine shaft and / or the second turbine shaft are preferably made of composite material, steel, aluminium, wood or a combination of these materials.

[0083] The connection connecting the first support arm to the first turbine blade and the connection connecting the first support arm to the first turbine shaft and the connection connecting the second support arm to the second turbine blade and the connection connecting the second support arm to the second turbine shaft preferably have rotational freedom in at least one dimension so that the connections do not transmit bending moments.

[0084] All bearings of a wind power plant are preferably equipped with a monitoring system which allows the condition of the bearings to be monitored remotely.

[0085] The counter-rotating wind turbines are preferably equipped with a Supervisory Control and Data Acquisition (SCADA).

[0086] The stationary platform mooring and power take-off cable connection is preferably mounted to the lower end of the second turbine shaft.The stationary platform may have hydrodynamic damper plates to increase rotational stability and mitigate any torque fluctuations from the mooring system.

[0087] Power cables connected to the platform moorings are preferably connected to a marine substation or connection point on the seafloor for transmission of power to shore.

[0088] The tower preferably comprises at least one buoyancy unit and / or preferably comprises a ballast unit.

[0089] The tower preferably comprises a buoyancy unit adapted to be positioned at the surface of a body of water in which the wind power plant is arranged.

[0090] The lower part of the tower preferably comprises a nacelle, which preferably comprises a ballast unit.Therefore, the ballast unit can form a part of the nacelle of the wind power plant.

[0091] The nacelle may also be provided with a hydrodynamic wing on the outside. The wing may be controlled to provide a stabilizing effect for the wind turbine.

[0092] The mooring system is preferably rotatably attached to the ballast unit, for example using a turret, but other attachment means may also be used to attach the mooring system to the wind power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Non-limiting embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

[0094] Figure 1 A perspective view of a wind power plant comprising counter-rotating wind turbines according to the invention is shown, wherein the wind power plant is arranged to float offshore in a body of water.

[0095] Figure 2 A perspective view of a wind power plant comprising counter-rotating wind turbines according to the invention is shown, which wind power plant can be installed on a suitable foundation on shore.

[0096] Figure 3 A perspective view of a wind power plant comprising counter-rotating wind turbines according to the invention is shown, wherein the wind power plant is arranged to float offshore in a body of water.

[0097] Figure 4 An example of a swept area of ​​a first wind turbine rotor and a second wind turbine rotor is shown when the first turbine shaft and the second turbine shaft of the first wind turbine and the second wind turbine, respectively, are tilted relative to a vertical line.

[0098] Figure 5 An imaginary volume delineated by at least one first turbine blade or at least one second turbine blade is shown when the first turbine shaft or the second turbine shaft, respectively, is inclined relative to a vertical line.

[0099] Figure 6 A wind power plant comprising counter-rotating wind turbines according to the invention is shown, wherein a first blade tip of a first turbine blade and a second blade tip of a second turbine blade are provided with respective fins.

[0100] Figure 7 An adjustable attachment of first and second turbine blades to the first and second turbine shafts is shown, whereby the first and second blade angles can be adjusted.

[0101] Figure 8 The lower part of a wind power plant is shown, comprising a buoyancy unit and a nacelle containing a generator, wherein the nacelle is rotatably connected to a mooring system.

[0102] Fig. 9 A turbine blade that may be used with the present invention is shown.

[0103] Fig.10 Shown in more detail Fig. 9 Shown is how a first turbine blade and a second turbine blade may be attached to a first turbine shaft and a second turbine shaft, respectively. DETAILED DESCRIPTION

[0104] Figures 1 to 10 is an embodiment of a wind turbine 10 according to the invention which is arranged on a wind power plant 11 also according to the invention.

[0105] exist Figure 1 In FIG. 6 , a wind power plant 11 is shown, comprising a wind turbine 19 . The wind power plant 11 shown in the figure is a semi-submersible wind power plant floating in a body of water having a surface 65 .

[0106] The wind power plant 11 comprises a first turbine rotor 36 and a second turbine rotor 47. As shown, the first turbine rotor 36 comprises at least one first turbine blade 38, but preferably comprises a plurality of first turbine blades 38. The first turbine blade 38 is mounted on a first turbine shaft 37. The first turbine shaft 37 is rotatable about an axis of rotation A.

[0107] As shown, the second turbine rotor 47 includes at least one second turbine blade 49, but preferably includes a plurality of second turbine blades 49. The second turbine blade 49 is mounted on a second turbine shaft 48. The second turbine shaft 48 is rotatable about the same axis of rotation A.

[0108] like Figure 6As shown, the first turbine blade 38 and the second turbine blade 49 may be provided with respective first and second vanes 43 and 54 mounted to the first and second blade tips 39 and 50 , respectively.

[0109] The first turbine rotor 36 and the second turbine rotor 47 are arranged so that they rotate in opposite directions. Therefore, they are coaxial and rotate around the same rotation axis A in opposite directions.

[0110] In case the wind power plant 11 comprises a tower 30 , when the wind power plant 11 is in operation, the tower 30 and thus the axis of rotation A will be arranged such that the tower 30 and the axis of rotation A are inclined relative to the horizontal plane, as shown.

[0111] As shown, the first turbine shaft 37 may be considered to form at least a portion of the upper portion 32 of the tower 30 of the wind power plant 11 .

[0112] The lower part 31 of the tower 30 comprises a buoyancy unit 12. As shown, the buoyancy unit 12 may be arranged so that it is partially submerged in the water. The buoyancy unit 12 may also be arranged so that it is fully submerged in the water.

[0113] The lower part 31 of the tower 30 further comprises a nacelle 14. A generator 17 of the wind power plant 11 is driven by the counter-rotating first and second turbine shafts 37, 48 of the wind turbine 10 and is arranged in the nacelle 14.

[0114] like Figure 8 As shown, the generator 17 includes a stator portion 18 mounted to the second turbine rotor 48 and a rotor portion 19 mounted to the first turbine rotor 37, i.e., the nacelle 14. The generator 17 is preferably a permanent magnet synchronous generator. For example, the rotor portion 19 of the generator 17 may include neodymium iron boron magnets or ferrite magnets, while the stator portion 18 of the generator 17 includes an armature winding, which preferably includes a high voltage cable.

[0115] The generator 17 generates electricity, which may be exported via at least one export cable 20 to an external user or an external storage facility.

[0116] The lower part 31 of the tower 30 is preferably firmly attached to the upper part 32 of the tower 30 by means of a connection device 34. For example, the connection device 34 may be a conventional flange connection, wherein the lower part 31 and the upper part 32 of the tower 30 are provided with respective flanges, such as Figure 8As shown, the flanges are bolted together by a suitable number of bolts. The lower part 31 and the upper part 32 of the tower 30 are therefore not connected in a rotatable manner and will rotate together when the wind power plant 11 is in operation.

[0117] The second turbine shaft 48 passes through the buoyancy unit 12 and enters the nacelle 14, and is rotatably supported in the tower 30 by a plurality of bearing devices 27. These bearing devices 27 are as shown in FIG. Figure 6 and Figure 8 Thus, the second turbine shaft 48 is rotatable relative to the tower 30 including the buoyancy unit 12 and the nacelle 14 .

[0118] At the lower end of the tower 30 and the nacelle 14, a mooring arrangement 22 is provided, which includes a mooring line connector 23. Figure 8 As shown, the mooring line connector 23 is rotatably supported by a bearing device 24 arranged in the nacelle 14. The mooring line connector 23 is designed to allow relative movement between the mooring line connector 23 and the nacelle 14. For example, the mooring line connector 23 may be a turret that allows relative rotation between the turret and the nacelle 14.

[0119] The mooring device 22 also includes at least one, but preferably a plurality of mooring lines 25, which are attached to the mooring line connector 23 at one end and to the seabed at the other end. The mooring system 22 is preferably of a well-known design, such as for anchoring of a semi-submersible vessel, and will not be described in detail here.

[0120] like Figure 8 As shown, the lower part 31 of the tower 30 is preferably provided with one or more ballast units 15. The ballast unit 15 may be a ballast tank for water, so that the amount of additional weight at the lower part 31 of the tower 30 can be adjusted. Alternatively, the ballast unit may also be a solid weight, for example made of steel or iron, which is arranged in the nacelle 14. The ballast unit may also include a combination of a ballast tank and a solid weight.

[0121] like Fig. 9 and Fig.10 As shown, the first turbine blade 38 and the second turbine blade 49 are provided with at least one, but preferably a plurality of, connecting arms 57, such as two connecting arms 57 shown in the figure. As shown, the connecting arms 57 may be an integral part of the first turbine blade 38 and the second turbine blade 49. Alternatively, the connecting arms 57 may be separate parts that are securely fastened to the first turbine blade 38 and the second turbine blade 49 by appropriate fastening means.

[0122] A blade connector 61 is provided at the end of the connecting arm 57. The blade connector 61 may be an integral part of the first turbine blade 38 and the second turbine blade 49. Alternatively, the blade connector 61 may also be a separate part, which is securely fastened to the connecting arm 57 by appropriate fastening means. Fig. 9 As shown, the blade connector 61 is provided with bolt holes 62 .

[0123] The first turbine shaft 38 and the second turbine shaft 49 are provided with a bolt connector 58, which is firmly attached to the first turbine shaft 38 and the second turbine shaft 49 by, for example, welding. The bolt connector 58 is provided with a bolt hole corresponding to the bolt hole 62 on the blade connector 61, and the bolt 60 is arranged to pass through the bolt hole of the bolt connector 58 and the bolt hole 62 of the blade connector 61. Thereby, the first turbine blade 38 and the second turbine blade 49 are rotatably connected to the first turbine shaft 37 and the second turbine shaft 48, respectively, and can rotate around the bolt 60.

[0124] The first turbine rotor 36 is preferably provided with at least one first support arm 41. The number of support arms 41 will generally be the same as the number of first turbine blades 38. The length of the first support arm 41 may be adjustable or fixed.

[0125] One end of the first support arm 41 may be rotatably attached to the first turbine blade 38, and the other end may be rotatably attached to the first turbine shaft 37. Figure 7 As shown, the first support arm 41 may include a first telescopic section 44 and a second telescopic section 45. The first blade angle 40 (see Figure 3 ), i.e. the angle between the first turbine blade 38 and the first turbine shaft 37, is thus adjustable. Alternatively, one end of the first support arm 41 may be slidably attached to the first turbine blade 38, or more preferably to the first turbine shaft 37, to adjust the angle between the first turbine blade 38 and the first turbine shaft 37. Thus, the inclination of the first turbine blade 38 relative to the first turbine shaft 37 is adjustable, but makes the first blade angle 40 an acute angle.

[0126] Likewise, the second turbine rotor 47 is preferably provided with at least one second support arm 52. The number of second support arms 52 will generally be the same as the number of second turbine blades 49. The length of the second support arms 52 may be adjustable or fixed.

[0127] One end of the second support arm 52 may be rotatably attached to the second turbine blade 49, and the other end may be rotatably attached to the second turbine shaft 48. Figure 7As shown, the second support arm 52 may include a first telescopic section 44 and a second telescopic section 45. The second blade angle 51 (see Figure 3 ), that is, the angle between the second turbine blade 49 and the second turbine shaft 48, is thus adjustable. Alternatively, one end of the second support arm 52 may be slidably attached to the second turbine blade 49, or more preferably to the second turbine shaft 48, to adjust the angle between the second turbine blade 49 and the second turbine shaft 48. Thus, the inclination of the second turbine blade 49 relative to the second turbine shaft 48 is adjustable, but preferably the second blade angle 51 is an acute angle.

[0128] exist Figure 3 In the embodiment, the inclination of the first turbine blades 38 relative to the first turbine shaft 37 (and the rotation axis A) is between 40 and 50 degrees, and is closer to about 45 degrees. The inclination of the second turbine blades 49 relative to the second turbine shaft 48 (and the rotation axis A) is also between 40 and 50 degrees, and is closer to about 45 degrees.

[0129] Furthermore, the inclination of the tower 30 and the axis of rotation A relative to the horizontal, and therefore relative to the surface 65 of the water, is between 40 and 50 degrees, and more closely to about 45 degrees.

[0130] When the first blade angle 40 is approximately the same as the inclination of the rotation axis A relative to the horizontal plane, the first turbine blade 38 will be in a more or less horizontal position when the first blade tip 39 is in its lowest position. Thereby, the probability that the first turbine blade 38 will hit the water is reduced. At the same time, when the first blade tip 39 is in its highest vertical position, the first turbine blade 38 will be in a more or less vertical position and an optimal swept area is obtained.

[0131] When the second blade angle 51 is approximately the same as the inclination of the rotation axis A relative to the horizontal plane, when the second blade tip 50 is in its lowest position, the second turbine blade 49 will also be in a more or less horizontal position. At the same time, when the second blade tip 50 is in its highest vertical position, the second turbine blade 49 will be in a more or less vertical position and an optimal swept area is obtained.

[0132] As the first turbine rotor 36 and the second turbine rotor 47 rotate, the first turbine blades 38 and the second turbine blades will sweep the conical area 67, such as Figure 5 As shown. Figure 4 As shown, the swept area 68 swept by the first rotor blade 38 and the swept area 69 swept by the second rotor blade are elliptical in vertical projection.

[0133] like Figure 6As shown, the first support arm 41 and the second support arm 52 may be straight or curved.

[0134] For example, if the first blade angle 40 is fixed and the inclination of the first turbine blade 38 relative to the first turbine shaft 38 cannot be adjusted, the first turbine rotor 36 may also be provided with a first support rod 42, wherein one end of the first support rod is attached to the first turbine blade 38 and the other end is attached to the first turbine shaft 37.

[0135] For example, if the second blade angle 51 is fixed and the inclination of the second turbine blades 49 relative to the second turbine shaft 48 cannot be adjusted, the second turbine rotor 47 may also be provided with a second support rod 53, wherein one end of the second support rod 53 is attached to the second turbine blades 49 and the other end is attached to the second turbine shaft 48.

[0136] Reference numerals used in the description of the drawings:

[0137]

[0138]

[0139]

[0140]

Claims

1. A counter-rotating wind turbine comprising a first turbine rotor mounted on a first turbine shaft and a second turbine rotor mounted on a second turbine shaft, wherein: The first turbine shaft is rotatable about a rotation axis (A), and the second turbine shaft is rotatable in an opposite direction about the same rotation axis (A), wherein the first turbine rotor comprises at least one first turbine blade extending in an outward direction from the first turbine shaft, and wherein the second turbine rotor comprises at least one second turbine blade extending in an outward direction from the second turbine shaft, wherein at least one of the first turbine blades forms a first blade angle relative to the first turbine shaft, and at least one of the second turbine blades forms a second blade angle relative to the second turbine shaft, the first blade angle and the second blade angle being both acute angles when the wind turbine is in operation.

2. The counter-rotating wind turbine according to claim 1, in, When the wind turbine is in operation, the rotation axis (A) forms an acute angle with the horizontal plane.

3. A counter-rotating wind turbine according to claim 1 or 2, in, As at least one of the first turbine blades and at least one of the second turbine blades rotate about the rotation axis (A), at least one of the first turbine blades and at least one of the second turbine blades sweep respective conical areas.

4. A counter-rotating wind turbine according to claim 1 or 2, in, The first turbine rotor sweeps a first swept area when in operation, and the second turbine rotor sweeps a second swept area when in operation, and wherein the first turbine rotor and the second turbine rotor are configured such that when the axis of rotation (A) is vertical, the first swept area and the second swept area do not substantially overlap.

5. A counter-rotating wind turbine according to any one of claims 1 to 4, in, At least one second turbine blade and at least one second turbine blade are arranged such that when the second blade tip is at a vertically uppermost position in the rotational path of the second blade tip, at least one first turbine blade and at least one second turbine rotor are substantially vertical.

6. A counter-rotating wind turbine according to any one of claims 1 to 5, in, At least one of said first turbine blades is mounted or attached to said first turbine shaft by means of first connection means, and wherein at least one of said second turbine blades is mounted to said second turbine shaft by means of second connection means.

7. A counter-rotating wind turbine according to any one of claims 1 to 6, in, The first connection means is configured to allow adjustment of the first blade angle and / or the second connection means is configured to allow adjustment of the second blade angle.

8. A counter-rotating wind turbine according to any one of claims 1 to 7, in, The first blade angle and the second blade angle can be adjusted independently of each other.

9. A counter-rotating wind turbine according to any one of claims 1 to 8, in, The first blade angle can be adjusted such that the first blade angle is less than 70 degrees and greater than 20 degrees, and / or the second blade angle can be adjusted such that the second blade angle is less than 70 degrees and greater than 20 degrees.

10. A counter-rotating wind turbine according to any one of claims 1 to 9, in, The first blade angle can be adjusted such that the first blade angle is less than 50 degrees and greater than 40 degrees, and / or the second blade angle can be adjusted such that the second blade angle is less than 50 degrees and greater than 40 degrees.

11. A counter-rotating wind turbine according to any one of claims 1 to 10, in, At least one of said first wind turbine blades is of airfoil shape and / or at least one of said second wind turbine blades is of airfoil shape.

12. A counter-rotating wind turbine according to any one of claims 1 to 11, in, The first turbine rotor comprises at least one first support arm mounted to the first turbine blade and to the first turbine shaft, and the second turbine rotor comprises at least one second support arm mounted to the second turbine blade and to the second turbine shaft.

13. A counter-rotating wind turbine according to any one of claims 1 to 12, in, The swept area of ​​the first turbine rotor is 0% to 20% greater than the swept area of ​​the second turbine rotor.

14. A counter-rotating wind turbine according to any one of claims 1 to 13, in, At least one of the first support arms is airfoil-shaped and / or at least one of the second support arms is airfoil-shaped.

15. A counter-rotating wind turbine according to any one of claims 1 to 14, in, At least one of the first support arms and / or at least one of the second support arms is provided with a motion damper arrangement.

16. A counter-rotating wind turbine according to any one of claims 1 to 15, in, At least one of the first turbine blades is provided with a first airfoil mounted to a tip portion of at least one of the first turbine blades, and / or at least one of the second turbine blades is provided with a second airfoil mounted to a tip portion of at least one of the second turbine blades.

17. A counter-rotating wind turbine according to claim 16, in, The first airfoil is adjustably mounted to at least one of the first turbine blades and / or the second airfoil is adjustably mounted to at least one of the second turbine blades.

18. A counter-rotating wind turbine according to claim 16 or 17, in, The first wing is airfoil-shaped and / or the second wing is airfoil-shaped.

19. A counter-rotating wind turbine according to any one of claims 1 to 18, in, At least one of the first turbine blades has a length greater than a diameter of the first turbine shaft, and wherein at least one of the second turbine blades has a length greater than a diameter of the second turbine shaft.

20. A counter-rotating wind turbine according to any one of claims 1 to 19, in, At least one of the first turbine blades comprises a plurality of first blade sections connected or attached to one another, and / or at least one of the second turbine blades comprises a plurality of second blade sections connected or attached to one another.

21. The counter-rotating wind turbine of claim 20, in, Two adjacent first blade segments are attached to each other at an angle so that the two adjacent first blade segments form a non-linear first turbine blade, and / or two adjacent second blade segments are attached to each other at an angle so that the two adjacent second blade segments form a non-linear second turbine blade.

22. A counter-rotating wind turbine according to claim 20 or 21, in, At least one pair of adjacent first blade sections are hingedly attached to each other, and / or two adjacent second blade sections are hingedly attached to each other.

23. A counter-rotating wind turbine according to any one of claims 20 to 22, in, At least one of the first blade segments is attached to at least one of the first support arms and / or at least one of the second blade segments is attached to at least one of the second support arms.

24. A counter-rotating wind turbine according to any one of claims 1 to 23, in, At least a portion of at least one of the first turbine blades is bent upward or downward relative to the direction of the rotation axis (A), and / or at least a portion of at least one of the second turbine blades is bent upward or downward relative to the direction of the rotation axis (A).

25. A counter-rotating wind turbine according to any one of claims 1 to 24, in, At least a portion of at least one of the first turbine blades is bent forward or backward relative to the rotation direction of the first turbine rotor, and / or at least a portion of at least one of the second turbine blades is bent forward or backward relative to the rotation direction of the second turbine rotor.

26. A counter-rotating wind turbine according to any one of claims 1 to 25, in, At least one of the first turbine blades is bent at least partially in a circumferential direction around the first turbine shaft and / or at least one of the second turbine blades is bent at least partially in a circumferential direction around the second turbine shaft.

27. A wind power plant comprising a counter-rotating wind turbine according to any one of claims 1 to 26.

28. The wind power generation device according to claim 27, in, The wind power plant includes a generator driven by the counter-rotating wind turbines.

29. The wind power generation device according to claim 27 or 28, in, The first turbine shaft is mounted to a stator portion of the generator and the second turbine shaft is mounted to a rotor portion of the generator.

30. A wind power plant according to any one of claims 27 to 29, in, The stator part on the rotating first turbine shaft comprises a rectifier, enabling direct current to be transmitted via the rotating contacts.

31. The wind power generation device according to claim 30, in, The rectifier is configured to perform active rectification or to perform rectification using a diode.

32. A wind power plant according to any one of claims 27 to 31, in, The stator portion includes a first stator portion and a second stator portion, wherein the first stator portion is non-rotatable and the second stator portion is rotatable.

33. The wind power generation device according to claim 32, in, The first, non-rotatable, stator part is mounted to a tower of the wind power plant and the second, rotatable, stator part is mounted to the first turbine shaft.

34. The wind power generation device according to claim 33, in, The first stationary stator part is configured such that it is possible to use the first stator part as an electric machine, by which torque can be applied to the second turbine shaft.

35. A wind power plant according to any one of claims 27 to 34, in, The counter-rotating turbines are configured such that, in operation, the axis of rotation (A) is inclined relative to the horizontal.

36. A wind power plant according to any one of claims 27 to 35, in, The wind power generation equipment is configured so that: during operation, at least one of the first turbine blades forms a first blade angle with the rotation axis (A), the first blade angle being substantially equal to the inclination of the rotation axis (A) relative to the horizontal plane, and / or at least one of the second turbine blades forms a second blade angle with the rotation axis (A), the second blade angle being substantially equal to the inclination of the rotation axis (A) relative to the horizontal plane.

37. A wind power plant according to any one of claims 27 to 36, in, The wind power plant comprises a tower, wherein the tower is at least partially formed by the first turbine shaft.

38. A wind power plant according to any one of claims 27 to 37, in, The wind power generation equipment is a floating wind power generation equipment suitable for being arranged in a body of water.

39. A wind power plant according to any one of claims 27 to 38, in, The tower components are mounted to the anchoring system.

40. A wind power plant according to any one of claims 24 to 36, in, The anchoring system is configured to withstand any torque generated by the generator.

41. A wind power plant according to any one of claims 27 to 40, in, The tower comprises at least one buoyancy unit and / or ballast unit.

42. The wind power generation device according to claim 41, in, The tower comprises a buoyancy unit adapted to be positioned at the surface of a body of water in which the wind power plant is arranged.

43. The wind power generation device according to claim 41 or 42, in, The lower part of the tower comprises a ballast unit.

44. The wind power generation device according to claim 43, in, A mooring system is rotatably attached to the ballast unit.

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