NL2019168B1 - Wind turbine and method of installing thereof - Google Patents

Abstract

The present invention relates to a wind turbine, comprising: - a nacelle with a generator that is drivable by a rotor that comprises rotor blades, wherein the rotor blades convert wind power into energy; - a monopile tower, supporting said nacelle; and - a compartment configured to accommodate an energy storage medium to store the energy. The invention further relates to a method of installing such a wind turbine, comprising the steps of: - arranging said compartment in said monopile tower before transport; - transporting said monopile tower; and - driving said monopile tower into a seabed.

Description

Netherlands Patent Office © 2019168 © Application number: 2019168 © Application filed: July 4, 2017 © B1 PATENT © Int. CL:

F03D 9/10 (2018.01) F03D 9/17 (2018.01) F03D 13/25 (2018.01) F03D 9/18 (2018.01) F03D 13/40 (2018.01) F03D 9/19 (2018.01)

0 Application registered: © Patent holder (s): January 14, 2019 Fistuca B.V. in DELFT. © Request published: - © Inventor (s): Jasper Winkes in The Hague. © Patent granted: January 14, 2019 © Authorized representative: © Patent issued: ir. P.J. Hylarides et al. In The Hague. May 8, 2019

Wind turbine and method of installing © The present invention relates to a wind turbine, including:

- a nacelle with a generator that is drivable by a rotor that comprises rotor blades, including the rotor blades convert wind power into energy;

- a monopile tower, supporting said nacelle; and

- a compartment configured to accommodate an energy storage medium to store the energy.

The invention further relates to a method of installing such a wind turbine, including the steps of:

- arranging said compartment in said monopile tower before transport;

- transporting said monopile tower; and

- driving said monopile tower into a seabed.

NL B1 2019168

This patent has been granted regardless of the attached result of the research into the state of the art and written opinion. The patent corresponds to the documents originally submitted.

Wind turbine and method of installing

The present invention relates to a wind turbine, and to a method of installing such a wind turbine.

Energy production by wind turbines fluctuates significantly over time, both on short scale (hours / days) and long scale (weeks / months / seasons) time periods. Besides this, energy demand also fluctuates or time. As energy supply and energy demand both fluctuate independently from each other, wind turbines sometimes have a surplus of energy, and some time a shortage.

In order to reduce the likelihood of a temporary shortage of energy, some time a larger capacity wind turbine is installed. When the capacity of a whole wind power plant including multiple wind turbines is chosen larger than stipulated in a connection agreement with a transmission system operator, this is called 'transplanting'.

An object of the present invention is to provide a wind turbine, that is improved relative to the prior art and that is least one of the above stated problems is obviated.

Said object is achieved with the wind turbine according to the present invention, including:

- a nacelle with a generator that is drivable by a rotor that comprises rotor blades, including the rotor blades convert wind power into energy;

- a monopile tower, supporting said nacelle; and

- a compartment configured to accommodate an energy storage medium to store the energy.

The energy of the rotor is kinetic energy and normally converted to electrical energy using said generator, said electrical energy is delivered to a grid. Although the energy may be stored after a conversion to electrical energy, and may be subject to even further energy conversions, it is also conceivable that the energy of the rotor is used directly, eg for driving a pump that may be directly pressurize the energy storage medium.

According to the invention, energy may be stored in the energy storage medium when there is temporarily a surplus on energy, i.e. when the energy supply or the generated energy is temporarily higher than the demand for energy at that time. In this way, the wind turbine is capable of more closely matching energy supply and demand. It may also reduce the need for a wind power plant.

Alternatively, transplantation in combination with energy storage according to the invention will result in a wind power plant with a very stable and reliable energy delivery to the grid.

According to a preferred embodiment, the compartment is bounded by a circumferential wall or said monopile tower, and a partition wall and a further partition wall that are vertically offset. Having a compartment enclosed by two vertically offset partition walls has multiple advantages.

On the one hand, the partition wall and further partition wall strengthen the monopile tower, which becomes less vulnerable to deformations during transport in a lying state.

On the other hand, the compartment allows the introduction of a medium therein, continuously increasing a buoyancy or said monopile tower. In this way, the monopile tower may be transported in a floating state, reducing the need for ships with large transport capacity on deck. Moreover, if a part of the monopile tower extends the compartment, this extending part will not be floatable. Returns, the least buoyant part will position itself downward relative to the buoyant compartment under the influence of gravity, and may cause a substantial upright orientation of the floating monopile tower. A substantially upright orientation of the floating monopile tower largely agreed to the upright orientation of the floating monopile lower during driving said monopile tower into the seabed. In this way, the load on the cranes may be significantly reduced, and cranes with a smaller capacity may be sufficient for lifting the monopile tower before the monopile is supported by a gripper during driving or said monopile tower into the sea bed.

According to a preferred embodiment, the wind turbine further comprises a pressure release that is, after installation, arranged between the compartment and a seabed. The monopile tower may have one or two sections that extend fits the compartment that is arranged in said monopile tower. If there is only one section extending the compartment, this will be the least part of the monopile tower. However, if the monopile tower comprises sections extending on both sides of the compartment, the heavier or those extending sections will be the least buoyant section. Preferably, the pressure release is arranged in the least buoyant section of the monopile tower. In the situation described above or the substantially upright orientation of the floating monopile tower, the least buoyant section is automatically downward directed. The pressure release will be arranged below the compartment. While driving the monopile tower into the seabed, water that is enclosed inside said monopile tower, between the compartment and the seabed, may escape via the pressure release to the water body surrounding the monopile tower.

According to a further preferred embodiment, the pressure release is a through hole that is arranged in said circumferential wall or said monopile tower. Alternatively, the pressure release may be arranged in said partition wall and / or further partition wall. The latter case may include a conduit extending through at least the further partition wall and the compartment.

The invention is further related to a method of installing such a wind turbine, including the steps or:

- arranging said compartment in said monopile tower before transport;

- transporting said monopile tower; and

- driving said monopile tower into a seabed.

Further preferred are the subject of the dependent claims, hi the following description preferred expired of the present invention tire further elucidated with reference to the drawing, in which:

Figure 1 is a perspective view of a wind turbine;

Figure 2 is a cross sectional view of the monopile lower of the wind turbine or Figure 1;

Figure 3 is a schematic view of a first embodiment of a wind turbine according to the invention;

Figure 4 is a schematic view of a second embodiment of a wind turbine according to the invention;

Figure 5 is a view of a wind power plant with multiple wind turbines according to the invention being applied; and

Figures 6-9: show successive steps of transporting and installing a monopile tower or a wind turbine according to the invention.

The wind turbine 1 shown in Figure 1 comprises a nacelle 2 with a generator 3 that is drivable by a rotor 4 that comprises rotor blades 5. The rotor blades 5 convert wind power into energy. The wind turbine 1 further comprises a monopile tower 6, supporting said nacelle 2. The wind turbine 1 further comprises a compartment 7 configured to accommodate an energy storage medium 8 to store the energy.

The energy of the rotor 4 is kinetic energy and normally converted to electrical energy using said generator 3, said electrical energy is delivered to a (not shown) grid. Although the energy may be stored after a conversion from kinetic energy to electrical energy, and possibly even further energy conversions, it is also conceivable that the kinetic energy of the rotor 4 is used directly, eg for driving a pump 12 that directly pressurizes the energy storage medium.

The compartment 7 of the wind turbine 1 is bounded by an inner circumferential wall 9 or said monopile tower 6 and a partition wall 10 on an upper side of compartment 7.

The compartment 7 may be enclosed by the circumferential wall 9 or said monopile tower 6, said partition wall 10, and a seabed 25 being arranged by the monopile tower. However, in the preferred embodiment that is shown in the Figures, the compartment 7 is bound by a further partition wall 11 on a bottom side of the compartment 7. This has several advantages. Firstly, the compartment 7 is closed and may be very rigid, therefor capable of withstand relatively high pressures. Secondly, a pressure build up in compartment 7 will not be supported by the seabed 25. A separate compartment 7 thus avoiding the monopile tower 6 may be moved upward relative to the seabed 25due to pressure in said compartment 7. This is especially important if the energy storage medium 8 is floatable and the compartment 7 is relatively large. Thirdly, a compartment that is closed on all sides may be used to safely increase the buoyancy of the monopile tower 6. This is advantageous during transport and installing, as will be described in more detail below.

Thus, preferably, the compartment Ί is bounded by the circumferential wall 9 or said monopile tower 6, and the partition wall 10 and the further partition wall 11 that are vertically offset.

In Figure 3, the wind turbine 1 further comprises a pump 12 that is configured to pressurize said energy storage medium 8, and said compartment 7 is reinforced to contain the compressed energy storage medium. The compressed energy storage medium may be transported from the pump 12 to the compartment via a first conduit 13, and back via a second conduit 14.

The partition wall 10 and / or the further partition wall 11 are preferably dome shaped (Figure 2). The dome shape guarantees an optimal loading due to membrane stresses in the partition wall 10 and / or in the further partition wall 11. Therefore, a dome shape is capable of withstanding accelerations during driving said monopile into the seabed, and pressure inside the compartment 7 .

As shown in Figure 2, the partition wall 10 and / or the further partition wall 11 is arranged at or near an end of a truncated conical section 23 of the monopile tower 6. The partition walls reinforce the monopile tower 6 near the transitions of a truncated conical section to a straight section or a truncated conical section that has a different slope. At such a transition, the circumferential walls of the truncated conical section 23 and an adjacent section of the monopile tower 6 will be arranged at an angle a. This will lead to the force F being decomposed into an axial force F, and a radial force F, · (detailed view in Figure 2). The partition wall 10 and / or the further partition wall 11 reinforcement the monopile tower 6 relative to the radial force F _r component.

A method for failure energy generated by a wind turbine I comprises the steps of: providing a compartment 7, providing a medium 8 in said compartment 7, and failure energy generated by said wind turbine 1 in said medium 8. After an amount of time, which may be short term (order of hours / days) or long term (order of weeks / months / seasons), the energy stored in said medium 8 may be retrieved.

The energy storage medium 8 that is pressurized by pump 12 may be storage medium is water or air. Using air as medium, a compressed air energy storage (CAES) has been obtained, which is useful for peak shaving power supply over relatively short time periods in the order of hours and days. Internal pressure inside compartment 7 also reduces the chance of that segment of buckling.

Storage media 8 that may be more energy-rich, e.g. hydrogen and ammonia, and thus they may be used for peak shaving over long term (weeks / months / seasons) time periods. Both hydrogen and ammonia are obtained through a chemical process. In Figures 4 and 5, the wind turbine 1 comprises a chemical converter 15 (Figure 4), or is connected to a chemical converter 18 (Figure 5), which is configured to drive a chemical conversion.

The chemical converter 15, 18 may be configured to produce the hydrogen that is used as the energy storage medium 8, or configured to produce the ammonia that is used as the energy storage medium 8. Such processes, such as the Haber-Bosch process are known to the skilled person, and therefore they are not described in detail here.

The method may include the steps of:

- extracting nitrogen from air;

- making hydrogen from water by electrolysis using electricity generated by said generator 3;

- converting said hydrogen and nitrogen to ammonia (in a Haber-Bosch process); and

- said ammonia failure in said compartment 7.

In Figure 4, the chemical converter 15 may be power via a power supply line 16 that connects the converter 15 to the generator 3 of the wind turbine 1. Chemical compositions formed in the chemical converter 15, such as hydrogen and ammonia, may be fed via a transfer conduit 17 to the compartment 7.

In Figure 5, the chemical converter 18 is arranged remote from the wind turbines 1 in a wind power plant. The chemical converter 18 is arranged on a support 19, and power for the chemical converter 18 may be supplied via a (not shown) connection to a generator 3 or one or more than one of the wind turbines 1. Chemical compositions formed in the chemical converter 18, such as hydrogen and ammonia, may be fed via transfer conduits 20 to one or more than one compartment 7 or wind turbines I or said wind power plant.

After an amount of time, the energy storage medium 8, e.g. ammonia, may be extracted from the compartment. Ammonia may be used as a base chemical (e.g., for use in fertilizers) or as a fuel.

As described above, a compartment 7 enclosed inside the monopile tower 6 between a partition wall 10 and a further partition wall 11 is advantageous during transport and installation. A method of installing a wind turbine according to the invention preferably comprising the steps of:

- arranging said compartment 7 in said monopile tower 6 before transport;

- transporting said monopile tower 6; and

- driving said monopile tower 6 into a seabed 25.

An alternative way of malfunctioning energy in said compartment 7 is by using the wind power to heat the energy storage medium 8 with a heater. The energy storage medium 8 may be heated until a temperature of several hundred degrees Celsius, and stored in a compartment that is provided with a thermal insulation. The thermal insulation may comprise a foam layer and / or a coating.

The compartment being arranged in said monopile tower 6 before transport allows it to be filled with a medium to increase the buoyancy or said monopile tower 6. The method than further comprises the step of filling the compartment with a medium to increase a buoyancy or said monopile tower 6 prior to transporting said monopile tower, carrying transporting said monopile tower 6 comprises floating said monopile tower 6 on a water surface 24. By making the monopile tower 6 floatable, it can be transported in a very efficient way. A floater 26 may be arranged in a section (Figure 6) and / or around a section of the monopile tower 6, and the floater 26 and compartment 7 together provide the monopile tower 6 with sufficient buoyancy for it to be towed in a substantial lying state by a vessel (not shown) (Figure 6).

At the location where the monopile tower 6 is driven into the sea bed 25, the floater 26 is removed from the monopile tower 6, and a gas 27 (typically air) may be introduced as a substitute for buoyancy provided by floater 26 A pressure release 21, which will be described in more detail below, is temporarily closed in order to maintain the gas 27 in the respective section of the monopile tower 6. Because the compartment 7 and gas 27 provide buoyancy to the monopile tower, a relatively low capacity (not shown) crane is sufficient for upending the monopile tower 6 before gripping it with a (not shown) gripper (Figure 7).

A (not shown) floater 26 that is arranged on an external side of a section of the monopile tower 6 has the advantages that gas 27 may be introduced into that section while the external floater 26 still provides buoyancy. In this way, the buoyancy of the monopile tower 6 is very controllable and secure.

Thus, the monopile tower 6 is floatable, and a crane or limited capacity is sufficient for upending and moving said monopile to a (not shown) gripper. The gripper supports the monopile tower 6 when it is driven into the seabed 25.

The method thus may include the additional step of further increasing the buoyance of said floating monopile tower 6 by introducing a gas 27 in a section of the monopile lower 6 that is below said compartment 7 when said monopile tower 6 is arranged in a substantial upright orientation .

The monopile tower 6 further comprises a pressure release 21 that is, after installation, arranged between the compartment 7 and the seabed 25. In the Figures, the monopile tower 6 comprises sections extending on both sides of the compartment 7. The heavy of those extending sections will be the least buoyant section. The pressure release 21 is arranged in the least buoyant section of the monopile tower 6, ie the section that is automatically downward directed during the substantially upright orientation of the floating monopile tower 6. The pressure release 21 will be arranged below the compartment 7 While driving the monopile tower 6 into the seabed 25, water that is enclosed inside said monopile tower 6, between the compartment 7 and the seabed 25, may escape through the pressure release 21. The water escapes to the water body surrounding the monopile tower 6.

The pressure release 21 limits the flow rate at which water enclosed inside said monopile lower 6 may escape to the water body surrounding the monopile tower 6. In this way, the pressure release functions as a restriction that provides a controlled lowering of the monopile tower 6 during driving of said monopile tower 6 into the ground. In this way it is prevented that a monopile tower 6 may drop several meters in an uncontrolled way when it is driven through a soft layer in the sea bed.

In Figures 2 and 6, the pressure release 21 is embodied as a through hole 22 that is arranged in said circumferential wall 9 or said monopile tower 6.

For decommissioning of the monopile tower 6, the through hole 22 may be used as an input for supplying a medium in the space enclosed between the circumferential wall 9, the further partition wall 11 and the sea bed 25. Due to a pressure build up, the further partition wall 11 is pushed away from the sea bed 25, lifting the monopile tower 6 up out of the sea bed 25.

Although they show preferred embodiment of the invention, the above described are only intended to illustrate the invention and not to limit in any way the scope of the invention. Applied claims are followed by reference signs, such signs are included solely for the purpose of enhancing the intelligibility of claims and are in no way limiting the scope of claims. Furthermore, it is particularly noted that the skilled person can combine technical measures or the different expenses. The scope of the invention is therefore defined solely by the following claims.

Claims (25)

Conclusions A wind turbine comprising: - a gondola with a generator that can be driven by a rotor comprising rotor blades, the rotor blades converting wind power into energy; - a monopole mast that supports the gondola; and - a compartment configured to accommodate an energy storage medium for storing energy. 2. Wind turbine according to claim 1, wherein the compartment is delimited by an inner peripheral wall of the monopole mast and a partition wall at the top. 3. Wind turbine according to claim 2, wherein the compartment is bounded by a further partition on a bottom side. 4. Wind turbine according to claim 3, wherein the compartment is bounded by the peripheral wall of the monopole mast, and by the partition wall and the further partition wall which are arranged vertically at a distance from each other. The wind turbine according to at least one of the preceding claims, further comprising a pump configured to pressurize the energy storage medium, and wherein the compartment is reinforced to contain the compressed energy storage medium. Wind turbine according to at least one of the claims 2-5, wherein the partition wall and / or the further partition wall is dome-shaped. Wind turbine according to at least one of claims 1-6, wherein the energy storage medium is water or air. The wind turbine according to at least one of claims 1 to 6, wherein the energy storage medium is hydrogen. The wind turbine according to at least one of claims 1-6, wherein the energy storage medium is ammonia. The wind turbine according to at least one of the preceding claims, further comprising a chemical converter configured to effect a chemical conversion. The wind turbine of claims 8 and 10, wherein the chemical converter is configured to produce the hydrogen used as the energy storage medium. The wind turbine of claims 9 and 10, wherein the chemical converter is configured to produce the ammonia used as the energy storage medium. A wind turbine according to at least one of the preceding claims, wherein the compartment comprises thermal insulation and is configured to store a heated energy storage medium. A wind turbine according to at least one of the preceding claims, further comprising a pressure outlet. The wind turbine of claim 14, wherein the pressure discharge is at least one of: - arranged in a section of the monopole with the least buoyancy; and - after installation, installed between the compartment and a sea bed. 16. Wind turbine according to claim 14 or 15, wherein the pressure discharge is a bore which is arranged in the peripheral wall of the monopile mast. 17. Wind turbine according to claim 14 or 15, wherein the pressure discharge is arranged in the partition wall and / or the further partition wall. A wind turbine according to claim 2 and at least one of the claims 3-17, wherein the partition wall and / or the further partition wall is arranged at or near an end of a truncated conical part of the monopole mast. A monopaal comprising the features of the monopaal mast according to at least one of claims 1-18. A method for installing a wind turbine according to any of claims 1-18, comprising the steps of: - arranging the compartment in the monopile mast prior to transport; - transporting the monopile mast; and - driving the monopile mast into a seabed. The method of claim 20, further comprising the step of filling the compartment with a medium to increase buoyancy of the monopal mast prior to transporting the monopal mast, and wherein transporting the monopal mast driving the monopaal mast on a water surface. The method of claim 20 or 21, further comprising the step of driving the monopole mast into a substantially upright orientation prior to the step of driving the monopile mast into seabed. The method of claim 22, further comprising the step of driving the monopile mast into the seabed in a substantially upright orientation during the step of driving the monopile mast into the seabed. The method of claim 23, further comprising the step of further increasing the buoyancy of the floating monopole mast by introducing a gas into a portion of the monopaal mast that is lower than the compartment when the monopaal mast is in the substantially upright orientation is provided. A method according to at least one of claims 20 to 24, further comprising the step of, while driving the monopile mast into the seabed, releasing water enclosed by the monopole mast to an environment. 1/8