Power generation and / or power storage devices

Abstract

1. An electrical power generation and / or power storage apparatus comprising a floating flywheel, the flywheel being adapted, in use, to contact a body of liquid for rotation about a substantially vertical axis, the underside of the flywheel including circumferentially extending openings, gas being trapped in the openings by the surface of the liquid, in use, to define a gas cushion for supporting said flywheel.

Description

Technical Field

[0001] The present invention relates to power generation and / or power storage devices, and more particularly to such systems using floating flywheels.

Background Art

[0002] There is a widespread and publicly stated long-term vision globally to move away from fossil fuels for power generation and towards more environmentally friendly alternatives. Renewable energy sources such as wind and solar have obvious potential to reduce dependence on fossil fuels. Due to climate change issues among other factors, both technologies are being increasingly deployed. Both solar power generation and wind energy have intermittent outputs. The variability of these supply sources causes natural problems regarding the reliability of power grids that obtain most of their energy from these sources of generation. In particular, as the dependence on renewable energy sources increases, energy storage is widely understood to be fundamental to the evolving energy system.

[0003] There are several methods of electrical energy storage, including pumped hydroelectric energy storage, batteries, compressed air energy storage, and flywheels.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention has been made as a result of research related to the provision of an improved energy generation and / or energy storage device.

Means for Solving the Problems

[0005] In one embodiment, the present invention provides a power generation and / or power storage device including a floating flywheel, wherein the flywheel is configured to contact a liquid area for rotation about a substantially vertical axis when in use, and the lower side of the flywheel includes an opening that extends substantially circumferentially, and when in use, gas is trapped within the opening by the liquid surface to define a gas cushion for supporting the flywheel.

[0006] In this configuration, the flywheel is made to float on the surface of a gas cushion when in use. Contact of the flywheel with the liquid area provides a fluid seal to the gas cushion. The liquid area may be an open body of water such as a sea or lake, or it may include a suitable trough or other. The opening may face the liquid area so that the gas cushion is supported by the surface of the liquid area, or it may face a support surface other than the liquid area so that the gas cushion is supported by the support surface. In further configurations, the opening may face both the water area and a support surface other than the water area. Regardless of the configuration, the flywheel is stabilized in longitudinal and transverse motion by contact with the liquid area. Contact with the liquid area is preferably via one or more circumferential hanging walls, in which case stabilization occurs by the displacement of one or more circumferential hanging walls into the liquid area.

[0007] The gas is most preferably air. The liquid is most preferably water. The opening extends substantially continuously around the entire circumference of the flywheel.

[0008] In this configuration, the flywheel is supported on one or more gas cushions, most preferably air cushions. The gas cushions play a role in reducing frictional forces. In addition, in the case of installation in open water, wave-induced motion is substantially reduced. The amount of gas cushion and the draft of the flywheel can be maintained or restored by injecting more gas. This may be done using an air compressor.

[0009] As mentioned above, the gas is not limited to air, but for simplicity, the following explanation will focus on providing an air cushion. However, as will be readily apparent to those skilled in the art, any of the described configurations can be appropriately modified to use a gas other than air.

[0010] The embodiment provides a large floating horizontal flywheel that stores mechanical energy by rotating around a vertical axis. This flywheel can function to store naturally occurring wind energy and / or converted electrical energy taken in elsewhere as rotational mechanical energy. Such mechanical energy can be substantially converted back into electrical energy as needed and distributed to end users by cables. Alternatively, this electricity can be used for other purposes. For example, this energy can be used on or adjacent to the apparatus to produce hydrogen by electrolysis, and then distributed to end users by pipeline, along with by-product oxygen, if necessary, by separate pipeline.

[0011] In the case of naturally occurring wind energy, the flywheel can be equipped with multiple attached sails.

[0012] Embodiments including an extremely large flywheel have the potential to store, generate, and distribute gigawatt-level energy.

[0013] According to one or more embodiments, the device can be installed offshore in open waters and moored to the seabed. In other embodiments, the device can float in or around a circular trough on land along the coast of a body of water.

[0014] In a preferred configuration, when installed in open water, the overall dimensions of the flywheel can be large enough to minimize the longitudinal and transverse motion of the flywheel relative to the incident wavelength, thereby keeping it substantially isolated from the incident wave. The minimum inherent overall dimensions required to achieve this isolation can be, for example, about 1500 meters in open water where a typical wave spectrum is dominant.

[0015] Effective gyro stabilization is a key feature of various implementations that also offers performance advantages.

[0016] The flywheel may be substantially annular in shape. The flywheel may include a cover that is airtight and closes the center of the annulus. The cover may include a disc that can be cellular, or a frame closed by an outer shell that can be made of steel, concrete, glass-reinforced plastic, or airtight fiber. The cover may close off openings.

[0017] The flywheel may, in any form, include a pair of spaced circumferential walls that hang down from the flywheel during use, in which case the opening is provided between the walls. One of the circumferential walls may be an outer wall, or both walls may be spaced radially inward of the outer circumference of the flywheel. Alternatively, the flywheel may include a single circumferential wall that hangs down from the flywheel during use, in which case the opening is provided by the circumferential wall. The circumferential wall may be located on the outer circumference of the flywheel, or may be spaced radially inward of the outer circumference of the flywheel. The circumferential wall preferably hangs down substantially vertically during use. The circumferential wall preferably penetrates the surface of the liquid during use. Such penetration provides a submerged surface on the liquid surface that supports the flywheel. As described above, the displacement of the circumferential wall into the liquid region provides stabilization in longitudinal and transverse motion.

[0018] In such offshore embodiments, surface friction between the rotating submerged surface and the surrounding water will generate a circulation. This can provide further available energy storage capacity and will play a role in reducing surface friction as a result of the decrease in relative velocity between the rotating submerged surface and the water.

[0019] Because most of the energy of the incident wave passes under the wall, propagates through the lowered water surface defining the underside of the air cushion, and then passes under the wall again to return to the open water area, thereby reducing the force of the incident wave, the apparatus in various embodiments becomes semi-permeable to waves. In this way, as the wave passes under the flywheel, the air displaced by the wave crest in the air cushion simply moves into the trough of the wave with virtually zero change in air pressure on the structure. This can be characterized by the observation that it behaves like a semi-submersible mechanism where the flywheel is supported by an air cushion but stabilized by elements / walls penetrating the surface, thereby separating buoyancy and stability.

[0020] The presence of air cushions and the minimal bending moment generated by the buoyancy of surface-penetrating elements that function as supports allow for the adoption of relatively lightweight structures.

[0021] The flywheel can be formed from any suitable material, such as steel or concrete, but other materials are not excluded. A preferred embodiment is formed from post-tensioned concrete.

[0022] A flywheel can feature a compartmentalized / cellular structure, where the compartments / cells can be ballasted with water. Ballasting the cells increases the polar second moment of inertia of the flywheel, thereby increasing its energy storage capacity at any angular velocity.

[0023] The water in the ballasted cell may be subject to significant centrifugal pressure, in which case the water can be drained tangentially to regenerate electrical energy. In certain embodiments, improved damage stability can be obtained by leaving an appropriate number of cells unsubmerged and / or by providing circumferential compartmentalization of the air cushion.

[0024] The fluid seal may include segmented labyrinths. The labyrinth can be formed by a plurality of connected cells formed by a hanging wall where each cell hangs from the flywheel 1 and an opposing wall that protrudes on the opposite side of the hanging wall.

[0025] According to one or more embodiments, electrical energy taken in from elsewhere can be reversibly converted by a fixed facility into rotational mechanical energy for storage by the flywheel at the interface between the fixed facility and the flywheel, and the flywheel is rotated by that rotational mechanical energy.

[0026] According to one or more embodiments, electrical energy taken in from elsewhere can be conducted to the flywheel, where it can be reversibly converted into rotational mechanical energy by equipment on the flywheel for storage by the flywheel, and the flywheel is rotated by that rotational mechanical energy.

[0027] According to one or more embodiments, equipment attached to the flywheel can directly convert wind energy into rotational mechanical energy for storage by the flywheel, and the flywheel is rotated by that rotational mechanical energy.

[0028] According to one or more embodiments, equipment attached to the flywheel can directly and reversibly convert rotational hydrodynamic energy from the surrounding water into rotational mechanical energy for storage by the flywheel, and the flywheel is rotated by that rotational mechanical energy.

[0029] Furthermore, desirable features are indicated in the dependent claims.

[0030] Hereinafter, embodiments of the present invention will be described with reference only to the drawings, as non-limiting examples. [Brief explanation of the drawing]

[0031] [Figure 1] These are a plan view and a cross-sectional elevation view showing an energy storage device according to the first configuration. [Figure 2] This is an enlarged partial cross-sectional view of the flywheel of the device in Figure 1, cut along line AA in Figure 1. [Figure 3] This figure shows the viewpoints A and B in detail. [Figure 4] This diagram shows the energy intake / transmission configuration along with an enlarged cross-sectional view of the flywheel. [Figure 5] Figure 5 shows a further energy intake / transmission configuration. [Figure 6] Figure 6 shows a further energy intake / transmission configuration. [Figure 7] Figure 7 is a diagram disclosing different ballasting and mooring configurations. [Figure 8] Figure 8 is a diagram disclosing different ballasting and mooring configurations. [Figure 9] Figure 9 is a diagram disclosing different ballasting and mooring configurations. [Figure 10] Figures 10A, 10B, and 10C are cross-sectional views of three different flywheel configurations. [Figure 11] Figures 11A and 11B show different onshore configurations. [Figure 12] Figures 12A and 12B show different sail configurations. [Figure 13] Figure 13 is a diagram disclosing different configurations of the sail configuration shown in Figures 12A and 12B. [Figure 14] Figure 14 is a diagram disclosing different configurations of the sail configuration shown in Figures 12A and 12B. [Figure 15] Figures 15A and 15B disclose different configurations of the sail configuration shown in Figures 12A and 12B. [Figure 16] Figure 16 is a diagram disclosing different configurations of the sail configuration shown in Figures 12A and 12B. [Figure 17] Figure 17 is a diagram disclosing different configurations of the sail configuration shown in Figures 12A and 12B. [Figure 18] Figures 18A, 18B, and 18C disclose different configurations of the sail configuration shown in Figures 12A and 12B. [Figure 19] Figure 19 is a diagram disclosing a typical damage stability enhancement configuration. [Figure 20] Figure 20 is a diagram disclosing a typical damage stability enhancement configuration. [Figure 21] This is a cross-sectional elevation view showing a preferred optimized flywheel configuration. [Figure 22] Figure 21 is a plan view showing the flywheel. [Figure 23] Figures 12A and 12B show the preferred optimized configuration C. [Figure 24] This is a partial cross-sectional view showing a preferred sealing configuration. [Modes for carrying out the invention]

[0032] Generally, embodiments of the present invention provide a device for power generation and / or power storage that includes a novel floating flywheel.

[0033] Throughout this specification, we assume the flywheel rotates clockwise, but it should be noted that counterclockwise rotation is also acceptable, as will be readily apparent to those skilled in the art.

[0034] Figure 1 shows a power generation and / or power storage device according to a first embodiment. The device includes an annular flywheel 1.

[0035] The flywheel 1 is buoyant and, during use, is configured so that the underside of the flywheel contacts the surface of the liquid area with the liquid surface facing it. The flywheel is configured to rotate about a substantially vertical axis. The underside includes an opening 2 that extends circumferentially. During use, the liquid surface traps gas within the opening. This provides a gas cushion that supports the flywheel 1 and gives the rotational friction significantly reduced as described above. In this configuration, preferably, the circumferential opening extends substantially continuously around the entire circumference of the flywheel 1. Alternatively, it may include multiple separate sections, as will be detailed below.

[0036] In this configuration, the flywheel includes a pair of spaced circumferential walls 3 and 4 that hang down from the flywheel 1 when in use, and the opening is located between the walls, as is clearly visible in section AA. In this configuration, a deck 5 extends between the walls and closes the upper side of the opening 2. The deck is closed in such a way that it confines the gas within the opening.

[0037] As shown in the figure, the walls preferably hang vertically when in use. Walls 3 and 4 penetrate the surface of the liquid when in use, and walls 3 and 4 thereby define a support surface for the flywheel 1.

[0038] In this configuration, the flywheel floats on the surface of a gas cushion confined within opening 2 during use. Contact of the flywheel with the liquid zone provides a seal to the gas cushion through walls 3 and 4. The flywheel 1 is stabilized in both longitudinal and transverse motion by contact with the liquid zone due to the displacement of walls 3 and 4 into the liquid zone. Opening 2 faces the liquid zone. In onshore configurations, such as those described later with respect to Figures 11 and 24, opening 2 may instead face a solid support surface such as the ground or a platform.

[0039] The flywheel 1 in this configuration has a depth Z, a deck width X, and an inner diameter Y. As will be apparent to those skilled in the art, increasing any of these dimensions increases the polar second moment of inertia of the flywheel 1, thereby increasing its energy storage capacity at any angular velocity.

[0040] Referring to Figure 1, an exemplary, non-limiting external electrical energy intake and distribution facility 6 is shown. It should be noted that the embodiments in Figure 1 are not limited to the presence or form of these facilities as described in the following paragraphs, and various alternative configurations are implementable, as will be apparent to those skilled in the art.

[0041] A typical energy generation module remains stationary in global coordinates as the flywheel rotates. The relative motion between the energy generation module and the flywheel is used to generate electricity or increase rotational mechanical energy by any suitable conventional means, not limited to, such as a wheeled bogie connected to a generator / motor supported on the inner surface of the energy generation module and leaning against the outer surface of the flywheel. Alternatively, a row of excitation coils or permanent magnets on the outer circumference of the flywheel, opposite a generating coil or power coil on the inner surface of the energy generation module, can form a generator or motor as required by the context. A further preferred alternative is an annular magnetic levitation orbit that serves a dual purpose: in addition to bearing some or all of the total weight supported on the air cushion, resulting in a reduction in the depth of the air cushion, a reduction in the hanging wall dimensions, and a reduction in frictional losses, it converts the incoming electrical energy stored as rotational mechanical energy and vice versa. Many suitable configurations will readily come to mind for those skilled in the art, and the present invention is not limited thereto.

[0042] The energy generation module can be supported, for example, by rails or ledges around the outer circumference of the flywheel on a suitable wheeled bogie or bearing, allowing for free relative circumferential movement and the freedom of vertical movement of the flywheel while it carries the energy generation module.

[0043] Alternatively, if power is generated on the flywheel for transmission or taken into the flywheel to be converted into rotational mechanical energy on the flywheel, the energy generation module may, as is readily apparent to those skilled in the art, simply hold slip rings, pantographs, or other conventional devices to send electricity to or from the flywheel.

[0044] In some exemplary configurations, the selected energy generation module also holds the upper end of a mooring leg consisting of cables and / or chains, in the conventional manner of offshore floating structures. In such cases, there may be three or more pairs of mooring legs arranged circumferentially to hold the flywheel in place, maintain the accompanying energy generation module in a global position, and allow the flywheel to move freely vertically over a desired vertical range.

[0045] In the alternative configuration, the energy generation module or integrated module does not need to hold the mooring leg pair. The module may be maintained in a global position by a suitable module connector, for example, as will be apparent to those skilled in the art.

[0046] The embedded module, as shown in Figure 1, is preferably a multi-processing module that also includes an energy generation module and power management equipment. The embedded module may include additional equipment, such as, but not limited to, an electrolysis unit for generating hydrogen and oxygen. The embedded module may further provide, for example, accommodation facilities.

[0047] In some configurations, the embedded module may be located on a fixed structure adjacent to the flywheel, in which case the energy generation module is mounted separately on the flywheel, and the electrical energy it generates is sent to the embedded module. For example, the electrical energy may be sent by one or more suspension cables or otherwise. In the case of suspension cables, they may first be suspended from the module connector before reaching the intended embedded module at a nearby circumferential location.

[0048] Figure 2 shows an exemplary but preferred configuration of a flywheel. The deck width X is shown in the enlarged section cut off along line AA in Figure 1.

[0049] As described above, opening 2 is provided so that an air cushion, which serves to support the flywheel, can be installed. When used in open water, the air cushion further reduces the force of the incident wave by isolating the flywheel's longitudinal and transverse motion responses from the incident wave that passes beneath the flywheel and propagates with little attenuation.

[0050] As mentioned above, it is preferable that the flywheel has a cellular structure. By providing a cellular structure, the amount (and cost) of material can be reduced, and the mass can be changed by ballasting. Note that either the wall or the deck can be ballasted in any combination that maintains a uniform mass distribution in the circumferential direction of the flywheel.

[0051] The energy storage capacity of flywheel 1 can be enhanced by increasing its mass, and therefore its polar second moment of inertia. The cellular structure allows for increasing the mass by ballasting water in cell 7. This provides an economical solution for varying the flywheel's mass and thereby managing its energy storage capacity and rotational angular velocity as needed.

[0052] In this configuration, it is preferable (though not required) that each cell is bounded by both radial and circumferential walls to minimize the free surface effect of unfilled cells on the overall hydrostatic stability of the flywheel. In preferred operational practices, the majority of ballasted cells are compressed to their full capacity to minimize the free surface effect.

[0053] Notably, the uniform air pressure beneath the entire flywheel structure, when realized, plays a role in reducing the bending moment formed in the cross-section shown in Figure 2, thereby enabling the adoption of a highly economical thin-wall design in the deck structure.

[0054] If necessary, a ballast system may be provided to allow selective ballasting of the cells. The ballast system includes a plurality of valves 8 and preferably further includes a pump 9. The ballast system allows for controlled injection and drainage of water into the cells 7.

[0055] Figure 2 shows, for illustrative purposes, a configuration that includes both ballasted cells (shaded) and anhydrous cells.

[0056] In this exemplary configuration, cell 7 is supplied with water by an injection manifold 10 and drained by a drain manifold 11, and is preferably controlled by a remotely operated valve 8. The present invention is not limited to such exemplary configurations. For example, alternative configurations may omit the manifolds. In this configuration, which includes manifolds 10 and 11, there are inlet 12 and outlet 13 connected to the injection manifold 10 and the drain manifold 11, respectively. The inlet 12 and outlet 13 are preferably oriented such that both ballasting and deballasting are assisted by the rotation of the flywheel. The ballast system can thus be implemented without using the pump 9. However, it is preferable that one or more pumps are provided as shown in the figure.

[0057] The pump will be particularly useful in assisting ballast when the water intake manifold is at a level above the water inlet during use, or when the flywheel is rotating at a speed insufficient to automatically prime the system.

[0058] The introduction of one or more pumps allows for further improvements in practicality in certain exemplary configurations, particularly when the pumps are configured to function as both pumps and turbines.

[0059] In a preferred configuration in which the captured electrical energy is converted into mechanical energy in the energy generation module by an electric bogie through the use exemplified above, or in which the outer circumference of the flywheel functions as the rotor of an electric motor / generator with the energy generation module forming a stator, the rotational mechanical energy thus converted is directly applied to the flywheel at this interface, thereby increasing its angular velocity. Alternatively, if it is desired to maintain a constant angular velocity, additional ballast may be added, for example, to increase the angular moment of inertia of the flywheel by a corresponding amount, typically to maintain the target tangential velocity at its set point. The reverse applies when regenerating electrical energy from stored rotational mechanical energy.

[0060] If electrical energy in the flywheel is converted from rotational kinetic energy stored by the flywheel, another preferred option is to allow the flow to enter the drain manifold 11 from the ballasted cell 7 under centrifugal pressure through the valve 8 to generate electrical energy, and then through the pump 9 which acts as a turbine, or through one or more separate turbines.

[0061] Conversely, if electrical energy from an external source, such as a wind farm or elsewhere, is taken into the flywheel 1 in such a way that it is converted from electrical energy to rotational kinetic energy stored by the flywheel 1, one preferred option for this conversion is that the taken-in electrical energy generates a tangential force on the flywheel 1, which powers a pump 9 that functions as a jet pump for draining high-energy water through a drain outlet, thereby increasing the angular velocity of the flywheel 1 and thus increasing the amount of rotational kinetic energy stored. The water thus drained through the drain outlet may be drawn from the ballasted cell 7 through a valve 8 to the drain manifold 11, thereby further reducing the polar second moment of inertia and helping to accelerate the rate at which the tangential velocity rises toward a target value.

[0062] Alternatively, the water drained from the drain port 13 may pass through the drain manifold 11 under centrifugal pressure, directly from the inlet port 12 through a portion of the manifold crossed over to the drain manifold (not shown), and then through a pump 9 that functions as a pump-driven turbine using the captured electrical energy to increase its tangential velocity, and be stored as rotational mechanical energy.

[0063] It should be noted that each of the above configurations may be implemented using a separate pump / turbine that can be mounted on a suitable manifold so that one or the other can function.

[0064] Flywheels based on the principles described herein exhibit a relatively flat performance curve, indicating that the “reciprocating” energy storage and recovery efficiency can withstand actual angular rotational speeds to some extent; however, in any particular design, it is expected that there will be a target tangential velocity and a corresponding angular rotational speed. By providing a ballast configuration such as the exemplary configuration described above or otherwise, the flywheel will be provided with the ability to, firstly, take in ballast when accepting electrical energy for conversion and storage as rotational kinetic energy, and secondly, discharge ballast in the reverse context of generating electrical energy from the rotational kinetic energy of the flywheel. This allows the total mass of the flywheel to be varied so that the pole second moment of inertia of the flywheel varies to compensate for the change in stored energy, thereby maintaining a constant tangential velocity, which in turn maintains peak operating efficiency and further usefully flattens the performance curve.

[0065] The flywheel 1 may optionally include drag members 14, as shown in example Figure 2. The form of the drag members 14 is not particularly limited. The drag members 14 may include plates. The use of drag members is of particular interest when the flywheel is positioned in open water. Such drag members 14 may be installed at regular points on the outer circumference of the flywheel 1. The drag members 14 may preferably be mounted in a retractable manner, in which case they can be opened as needed and stored flush with the outer circumference of the flywheel 1 when not in use. The drag members 14 may be mounted swivelly for such purposes. Many suitable mounting configurations will be readily apparent to those skilled in the art. Viewpoint A in Figure 3 shows a side elevation of an exemplary drag plate 14 fully extended, and also shows a recess 15 into which the drag plate 14 can be stored.

[0066] As mentioned above, one function of the air cushion is to limit surface friction between the flywheel 1 and the water by minimizing the wetted area. Some friction remains, which reduces the tangential velocity and works to circulate the surrounding water by dragging the water along with the wetted surface to some extent. By providing the drag member 14, some of the kinetic energy of this circulating water can be recovered. The velocity profile of the circulating water decreases as the radius increases away from the flywheel, but its effective size in plan view continues to increase radially outward over time as the energy increases, forming a recirculation around the flywheel. Such a recirculation is an extremely efficient storage of rotational kinetic energy that decays quite slowly and naturally.

[0067] It should also be noted that this recirculation absorbs energy from the flywheel 1, and as its size increases, the tangential velocity of the recirculation also increases near the interface with the outer wetted surface of the flywheel 1, reducing the relative velocity between the recirculation and the flywheel 1, thereby reducing the shear force between them and limiting the energy loss to the recirculation.

[0068] In this context, the drag member 14 can perform the following two functions.

[0069] Firstly, if it becomes necessary to stop the flywheel 1 as quickly as possible, for example, for unplanned maintenance or other reasons, the stored energy needs to be dissipated. If this exceeds the capacity of the power generation system to convert electrical energy, or the output or consumption capacity of the energy transmission and distribution equipment, a drag member 14 can be employed to receive increased drag, thereby slowing down the rotational speed. Such drag will create turbulence near the drag member 14, in which energy is permanently lost as heat. However, this drag also increases the size and kinetic energy of the recirculation, in which some of the lost energy will be stored.

[0070] Secondly, if the stored energy is significantly depleted by long-term demand with little or no replenishment, a situation may arise where the surrounding recirculation rotates faster than the flywheel 1. In such a situation, a portion of the flywheel's stored energy can be usefully recovered by employing a drag member 14 to increase the tangential drag force of the recirculation acting on the flywheel 1, that is, by a process opposite to the process described above.

[0071] Figure 3 shows a side elevation view of the inlet 12 and outlet 13 as described above, with particular reference to Figure 2. In the example configuration shown, the inlet 12 has a bell-shaped opening configured to facilitate inflow. As will be readily apparent to those skilled in the art, the inlet may be configured in other forms. Both the inlet 12 and outlet 13 are preferably housed in smooth nacelles as shown to minimize drag. Depending on the configuration, these nacelles may be retractable, in which case retracting them when not in use leaves a smooth circumferential surface on the flywheel to further limit drag.

[0072] The apparatus is preferably configured so that the velocity of the wastewater flow from the drain port 13 can be varied. In one configuration example, the drain port 13 can optionally be segmented into two or more retractable sections with gradually increasing inner diameters to form a draft pipe for slowing the flow out of the drain port without excessive turbulence loss. Figure 3 shows an example with such three sections. Other configurations may be different. Specifically, there may be alternative means implemented to control the velocity of the wastewater.

[0073] As described above, the flywheel according to the principle of the present invention generally has an optimized tangential velocity V TThe flywheel 1 will be designed to operate at or near its optimal performance point, which includes the optimal performance point. In such a case, the drainage velocity of the flow from the drain port 13 relative to the flywheel 1 can be set so that the flow has a velocity close to zero relative to the adjacent water being drained. Such a configuration will function to minimize turbulence losses. However, if the flywheel 1 is operating away from its optimal design point, it may be desirable to accelerate the rotational angular velocity of the flywheel 1 to reduce or eliminate the velocity mismatch between the discharged flow and the water in the recirculation, into which the discharged flow needs to mix without excessive loss.

[0074] The speed control using the configuration example shown in Figure 3 will be discussed in more detail below.

[0075] The flywheel has a tangential velocity V T When the fully designed value is reached, a relatively high relative velocity between the drainage from outlet 13 and the surrounding water may be appropriate. In such cases, only the first upstream section of the nacelle may be used, and the outlet diameter of the drainage port will be the smallest available diameter.

[0076] During startup, when the flywheel is still rotating at a low speed, the velocity mismatch between the drain and the surrounding water is much smaller, and it would be preferable for the drain to be able to decelerate more in the longer draft pipe before flowing out into the surrounding water to minimize energy loss. Here, all three divisions may be employed, for example (as shown in Figure 3), to minimize turbulence loss by more closely matching the velocity of the drain with the velocity of the surrounding water.

[0077] Furthermore, in the case of intermediate rotational speeds, it may be appropriate to use only two classifications.

[0078] As described above, it should be noted that, as will be readily apparent to those skilled in the art, alternative means of controlling the drainage rate by implementing the above control by a different method may be implemented.

[0079] Figure 2 shows the seabed 17. In extremely shallow waters, bottom clearance is limited, and the resulting circulating currents can cause erosion. This can be avoided by proper rock dumping in the area before installation.

[0080] In any annular configuration of the flywheel 1 including spaced-apart circumferential hanging walls 3 and 4, it should be noted that the walls may be substantially the same as or different from each other. The walls can be configured to include an inner circumferential wall 4 and an outer circumferential wall 3. Both the inner and outer circumferential walls may contain cells 7 so that they can be ballasted, or only one of the inner or outer circumferential walls may contain cells, or neither of the circumferential walls may contain cells. The inner and outer circumferential walls may have the same thickness, or they may have different thicknesses. Different combinations of these features may be provided in the exemplary configuration.

[0081] Figure 4 shows an example configuration in which the thickness of the outer perimeter wall 3 is greater than the thickness of the inner perimeter wall 4. Both walls have a capacity for ballast, but this is not necessarily required as explained above.

[0082] The outer circumferential wall 3 is located at the maximum diameter of the flywheel, and therefore its displacement in water is a major factor in maintaining the flywheel's hydrostatic longitudinal and transverse motion stability; thus, the outer circumferential wall 3 is made thicker. The inner circumferential wall 4 is a secondary factor for hydrostatic stability, and if sufficient hydrostatic stability is already more efficiently provided by the selected thickness of the outer circumferential wall, the thickness of the inner circumferential wall 4 may be selected primarily to provide sufficient structural strength.

[0083] In this case as well, the thickness and configuration of the deck 5 can also vary, as this is a separate consideration applicable to all annular flywheel configurations. The thickness can be set to maximize its volume, and therefore the mass of ballast water in the cell 7, in order to efficiently increase energy storage capacity. Notably, an advantage of the air cushion is that the weight of the deck, and the ballast if present, is uniformly supported. This makes it possible to create a relatively lightweight structure. The uniform support of the air cushion minimizes bending moment stress. This makes it possible to reduce the overall cost of the flywheel compared to a structure without such uniform support.

[0084] While not solely related to the above-described features of the flywheel 1 shown in Figure 4, the configuration in Figure 4 is also disclosed as an example in the transmission system 6, which will be described in detail below. Note that such a configuration may be incorporated into other devices, including flywheels configured in a different way, such as those described elsewhere in this application.

[0085] The transmission and distribution system 6 includes an embedded module on which a power management system is installed. This may include, for example, conventional cables for power transmission, such as high-voltage DC cables, but not limited to those. Furthermore, it may include pipelines, such as, but not limited to, steel pipelines, for transmitting and distributing hydrogen when hydrogen is optionally generated from electrical energy in the embedded module.

[0086] This type of energy transmission and distribution system is suitable for transmission from a fixed structure to which electrical cables can be attached, as shown in the figure. The electrical cables can be attached, for example, by pulling them up through a J-pipe, or by other means after installation to the supports or legs of the fixed structure. If a pipe is provided, a pipeline riser may be installed on the fixed structure for later subsea connection to the pipeline. Alternatively, (in the case of small diameters) they may be pulled up through a J-pipe.

[0087] Figure 5A discloses a configuration in which no fixed structures exist. Such a configuration can be implemented, for example, when the water depth is sufficient for the energy transmission and distribution system to be provided in the form of a flexible cable or flexible pipeline 19 that has sufficient structural integrity to hang from a flywheel to the seabed via a suspension line.

[0088] Figure 5B shows a detailed view of Figure 4, part B. Note that in this configuration example, the built-in module 6 is equipped with a helideck for access by maintenance personnel. The helideck is entirely optional.

[0089] Figure 6 discloses a further alternative configuration in which the integrated module 6 is positioned on a semi-submersible mechanism 20 moored to the energy generation module. Such a configuration may be useful in deep-sea environments. In such a configuration, it would be preferable to provide support means for the semi-submersible mechanism. In this example configuration, an articulated mooring frame 21 is provided. This is preferably configured to give the semi-submersible mechanism freedom of pitch, roll and swell. Furthermore, it may be configured to provide access to the flywheel 1 by maintenance personnel and equipment. Note that an optional horizontal configuration for the energy generation module is also shown, which can be implemented in the various alternative configurations described herein.

[0090] Figure 7 discloses a further configuration example including a flywheel 1 featuring a central inverted nacelle 23. Any of the energy systems described above can be implemented, and this configuration is not limited thereto. The central nacelle 23 provides an alternative means of taking in ballast. In such a configuration, the nacelle 23 is preferably in fluid communication with the cells 7 of the flywheel structure through suitable radially extending fluid transport members 24. In this configuration, these fluid transport members 24 include pipes. The pipes can be spoke-shaped. The liquid flowing into the nacelle 23 flows radially outward through the pipes under centrifugal pressure. Deballasting may be performed through suitable drainage ports, as described above or by other means. As in the configuration described above, a pump may or may not be provided, and the pump may function as a turbine or be provided in addition to a separate turbine.

[0091] Generally speaking, the pump / turbine may be omitted from any configuration to increase the flow rate of deballasting water. Such a configuration results in simplified auxiliary equipment installation and reduced surface friction.

[0092] Figure 8 shows an example configuration with mooring / support legs 25. Such mooring / support legs 25 can be attached to the central swivel 27 as shown in the figure. Nevertheless, they are preferably deployed on the seabed substantially within the planned footprint of the flywheel 1 to achieve a compact configuration.

[0093] Figure 8 also discloses an onboard module 26, which can be installed in any of the above-described configurations as needed, but is particularly suitable for configurations with onboard energy generation. The onboard module 26 can accommodate various auxiliary equipment and utilities as needed, which may be housed in the embedded module in other ways in alternative configurations, or otherwise arranged / housed.

[0094] Such conventional auxiliary equipment may include, but is not limited to, one or more of the following: • An air compressor to manage the pressure and volume of the air cushion and to replenish the air lost beneath the structure during extreme weather or by absorption into seawater. Voltage control that enables a combination of electrical energy supply from multiple sources and economical transmission and distribution to the onshore power grid. • Emergency power generation. • Main fire pump. • Temporary or permanent dwelling area. In any such dwelling space, a floor inclined toward the central flywheel axis can be installed. The inclination angle is determined by the target peripheral speed V. T In order to allow personnel to move around without being hindered, the line of action of the combined force of gravity and centripetal force can be set to simulate the standard line of action of gravity. • Ballasting and / or deballasting pumps. • Communication and AI-assisted instrumentation and control systems. • An electrolytic plant for generating, compressing, regulating, and distributing hydrogen. If necessary, it can also dry, pressurize, and distribute the by-product oxygen.

[0095] In configurations including a swivel 27, the swivel 27 may be provided for energy transmission and distribution via electrical cables and / or flexible hydrogen pipelines, as described above. The swivel 27 may also be configured to provide for the intake of electrical energy from an external source for storage as rotational kinetic energy.

[0096] In a preferred configuration, the swivel includes a buoyancy tank 30. The buoyancy tank 30 is preferably configured to partially submerge when in use.

[0097] The buoyancy tank 30 can help support the weight of the components of the flywheel 1. The buoyancy tank 30 can help support the weight of one, more, or all of the following components if they are provided: namely, the components are a swivel, a helideck 31, and spoke elements which may transport liquid as described above or be purely structural as in the diagrammatic configuration.

[0098] In addition to the above, or in lieu thereof, if mooring / support legs 25 are provided in the buoyancy tank 30, the mooring / support legs 25 may be configured such that their lines of action intersect with the swivel 27 at the position where the swivel 27 contacts the spoke element 24. Such a configuration minimizes the significant bending moment acting on the spoke element due to the lateral force suppressed by the support / mooring legs.

[0099] As described above, the flywheel 1 may optionally be equipped with a helideck 31. If provided, the helideck can be positioned in the center of the flywheel. In a configuration with spoke elements 24, the spoke elements 24 can provide support to the helideck 31 and can also provide access facilities. In a closed circular configuration of the flywheel, such as that shown in Figure 10A, the helideck can, for example, simply be marked on the deck. As can be expected within the scope of this disclosure, a sufficiently large flywheel will have a sufficiently clear approach path in the center for a helicopter to land. Also, in the central position, the rotational speed of the flywheel will be sufficiently slow during operation so as not to interfere with helicopter operations. For example, a large flywheel may take several minutes to complete one rotation.

[0100] Figure 9 shows a configuration similar to that of Figure 8, namely a configuration including a swivel 27, but further including a central inverted nacelle 23 as described with respect to Figure 7. The swivel 27 and nacelle 23 may be combined as a single unit. Similar to the configuration of Figure 7, the spoke elements 24 preferably include pipes for ballast. A mooring support / leg 25 is provided according to the configuration of Figure 8.

[0101] As stated above, and as will be readily apparent to those skilled in the art, the different features / combinations of features of the different configurations described above may be combined / modified. Specifically, the disclosure of certain features combined with other features of a particular configuration does not link those features together. These embodiments are non-limiting and are for illustrative purposes only.

[0102] Figures 10A, 10B, and 10C show three different flywheel structure configurations that can be implemented in configurations that include any of the features described above.

[0103] Figure 10A shows a closed circular configuration, which contrasts with the annular flywheel configuration described above. Because the closed configuration involves only one wetted surface penetration, it generates lower surface friction than the annular configuration.

[0104] Figure 10B shows a ring-shaped configuration. If this has the same planar surface area and mass as the closed circular configuration in Figure 10A, it will have a greater energy storage capacity because its mass is concentrated near its outer circumference.

[0105] Figure 10C shows a layered annular structure. If this has the same planar dimensions as the structure in Figure 10B but twice the mass, it will have twice the energy storage capacity.

[0106] However, the target tangential velocity V for any flywheel configuration T It should be noted that the values ​​can be selected to have similar maximum values ​​that limit surface friction between the outer surface and the surrounding water to a reasonable level. The upper limit of the tangential velocity may be set, for example, to 80 km / h. For example, a closed circular configuration as shown in Figure 10A and a layered annular configuration as shown in Figure 10C have the same tangential velocity V T If it has a larger diameter (assuming it does), the latter's inherent energy storage advantage is negated by the lower rotational angular velocity resulting from the larger diameter.

[0107] Figures 10A to 10C are provided to illustrate the design principles described herein and are not otherwise limiting.

[0108] Figure 11 shows an exemplary, non-limiting flywheel in a complete cross-sectional view. This flywheel has a layered annular structure, but it is not limited to this configuration. The flywheel can be annular and formed by any of the above-described configurations. Alternatively, the flywheel may be formed in a closed circular configuration.

[0109] Figure 11A shows an onshore configuration option in which the lower ends of the inner and outer circumferences of the flywheel are submerged in separate troughs 33 and 34 that are perfectly circular in plan view.

[0110] Figure 11B shows another onshore configuration option in which the end is submerged in a single trough 35.

[0111] The choice between these two options is an economic issue. For example, separate troughs may require less excavation in site than a single trough. However, to economically maintain the required target head of the air cushion, airtight blinds may be needed in the exposed ground between the two concentric troughs in a configuration including separate troughs. As will be readily apparent to those skilled in the art, the troughs can be constructed in any suitable conventional manner.

[0112] Unlike offshore flywheels, in onshore configurations, water may be a separate quantity, thus reducing the drag on the flywheel or the target tangential velocity V. T It should be noted that, in order to increase the energy storage capacity, it is possible and sometimes desirable to add friction-reducing chemicals, such as but not limited to long-chain polymers, to water.

[0113] It should also be noted that site economics can be improved by selecting the height of the flywheel so that the excavation beneath it to create ground clearance provides enough excavated soil to construct the embankment that supports the separate outer trough.

[0114] Multiple energy generation modules 6 may be provided. There may be three or more equally spaced energy generation modules held in predetermined positions in the circumferential and radial directions by a suitable support structure. The vertical height of the energy generation modules can be controlled by the position of the flywheel. The support structure can also be configured to maintain the flywheel in a predetermined position in a plan view.

[0115] The example onshore configuration is a ring shape, but closed circular configurations can be included in the same way.

[0116] It should be noted that the comparative economic measures for closed circular configurations, annular configurations, and layered annular configurations differ in the case of onshore configurations from the measures that control the choice of offshore configurations, for reasons including the following: Having a minimum overall diameter of approximately 1500m eliminates the need to isolate the flywheel from the incident spectral wave energy. Smaller diameters may be sufficient to meet the field requirements of onshore flywheels. Only the outermost, separate trough is needed. • Because the air cushion extends across the entire planar area of ​​the flywheel, the area of ​​blinding can be substantially larger.

[0117] Regarding offshore installations, other systems and considerations remain, and it should be noted that, as will be readily apparent to those skilled in the art, various configurations of the offshore configurations described herein can be introduced into onshore configurations.

[0118] As briefly mentioned, this device has so far primarily been described in terms of the storage of externally generated energy. Referring to Figures 12 to 20, we will now consider power generation using this device. The device can be configured to generate power using wind power, which provides rotational kinetic energy to the flywheel for storage without any conversion.

[0119] For this purpose, any flywheel 1 in any configuration described herein may be equipped with a plurality of mounted sails 37. The sails can be mounted on the deck 5 of the flywheel and substantially form a large cross-flow wind turbine. The sails may be mounted in other ways. As will be apparent to those skilled in the art, any such sail can take many configurations. Several non-limiting sail configurations are described below.

[0120] Figure 12A shows an example configuration with a sail. This configuration preferably includes a continuously variable sail configuration. In this example configuration, a single flexible sail is provided that can be twisted to the optimal attack angle for the prevailing wind direction at any altitude in the fine grooves above the water.

[0121] This configuration accurately takes into account continuously variable wind speed and direction at different altitudes. Such variations occur naturally, but are also characteristics of the flow through the cross-flow turbine. In this configuration example, there is preferably a rigid vertical mast 38. Taking into account the wind load from the sail that this mast corresponds to, the mast can be segmented into several segments. The number of segments can be determined based on the maximum allowable bending moment and axial Euler buckling load of each mast segment.

[0122] Figure 12A shows a configuration including two such segments, and as can be seen in accordance with the above description, any configuration provided by this principle may have more or fewer segments. The vertical length of each such segment is preferably increased by providing universal joints where the segment connects to a flywheel or another segment, thereby substantially eliminating the bending moment at these intersections. Each segment may be constrained circumferentially and radially inward in plan view by rigging 39 which can preferably be diagonal, and radially outward by rigging 40 which can be substantially horizontal.

[0123] Appropriate instrument / sensing devices may be provided to determine the continuously changing optimal attack angle and / or aerofoil shape of the continuously variable sail configuration at stress levels in each altitude increment and / or length increment of the mast segment. As will be readily apparent to those skilled in the art, an AI system equivalent to those used in advanced aviation operations may be implemented.

[0124] Figure 12B shows a sail configuration similar to that of Figure 12A. The configuration in Figure 12B also includes multiple sail sections. However, this configuration employs multiple rigid sail sections. Each section can be configured, for example, in the same way as the wings of a conventional aircraft. While the use of rigid sail sections eliminates the need for a separate rigid vertical mast, configurations with such masts are also possible. Each individual sail section can be rotated independently to match the average wind speed and direction over its length in order to obtain the best available direction and magnitude of lift across that section. The more sections there are, the more accurately the sail sections can follow the dominant wind speed and direction at each altitude step. Figure 12B shows four such sections as an example. However, it is not limited to these; more or fewer sections can be used. Similar to Figure 12A, rigging 39 and 40 are provided to support the sail structure. When considering the number of sections to be implemented, increasing the number of sail sections will increase the required rigging. More rigging leads to greater drag. It would be desirable to strike an efficient balance.

[0125] Similar to the configuration in Figure 12A, appropriate instrument / sensing devices may be provided for input to the sail control system. In this case, an AI system can also be implemented.

[0126] Figure 13 shows a plan view of the configuration shown in Figure 12A. Note that Figure 13 partially shows two possible rigging options labeled A and B, respectively. Understand that only one of these rigging configurations can be implemented per equipped mast at a time. According to configuration A, each strand of the rigging 39 extends to the center of the flywheel. In configuration B, each strand 39 extends to be supported radially outward from the center of the flywheel. Appropriate support structures may be provided for this purpose. Naturally, in configurations where the flywheel is not annular, the top deck becomes available for attaching the ends of the rigging strands. The cost and operational drag economies will likely determine the preferred configuration of the rigging for any given design. Also, alternative configurations to A and B will be readily apparent to those skilled in the art. As mentioned above, these configurations are illustrative and can be modified or altered in many ways, as will be apparent to those skilled in the art.

[0127] It should be noted that, for maintenance purposes and to return the system to the operational configuration shown in the diagram afterward, equipment may be provided to adjust the length of the rigging cables so that the entire sail and rigging system can be safely and flatly positioned on the flywheel deck, either radially or circumferentially.

[0128] Figure 14 is shown to illustrate a method in which both the aerofoil shape of the continuously variable sail configuration described in Figure 12A and the rigid sail configuration described in Figure 12B are inverted, and a symmetrical shape is also adopted with respect to the average wind direction indicated by the arrow.

[0129] From this wind direction, the sail section, regardless of its specific configuration, can be configured to adopt an aerofoil shape as shown in the figure, thereby allowing the sail section in the distal and proximal halves of the flywheel shape to contribute to clockwise rotation. The sail section at the junction of the proximal and distal halves preferably has a symmetrical transition shape as shown in the figure. The leftmost sail section is preferably perpendicular to the wind direction to contribute to clockwise rotation. The rightmost sail section preferably has a symmetrical transition shape with respect to the wind direction so as to face the wind direction to minimize drag.

[0130] It should be noted that the orientation and shape of each aerofoil section are preferably not simply maximized by the control system to provide the maximum lateral lift, and the parameter controlling the tangential velocity can be the moment of lateral lift about the vertical axis of the center of rotation. Therefore, the control system preferably continuously calculates and maximizes the product of the lift and the moment arm about the central axis, and adjusts the aerofoil shape and direction accordingly. Thus, the control system can be configured to set an attack angle that generates lift in the direction of a larger moment arm, even if the lift is less than the maximum lift.

[0131] Referring next to Figures 15 to 18, non-limiting configurations of mechanical components for a control system that orients a sail to the appropriate shape and direction are shown. The system of this disclosure can be implemented for either a continuously variable sail configuration or a rigid sail section. While described in the context of a rigid vertical mast, it can be appropriately adapted for use in mast-less configurations, including, but not limited to, configurations that include a rigid sail section as described above. As will be readily apparent to those skilled in the art, many alternative mechanical configurations are also possible.

[0132] Figure 15A discloses a short aerofoil shape control cylinder 41 surrounding a rigid vertical mast 38. The aerofoil shape control cylinder 41 can be rotated in both directions relative to the rigid vertical mast 38 as shown, by an actuator 43 mounted on a bush in the rigid vertical mast 38 to hold a spherical bearing 42 and drive a gear 44 that engages with an opposing rack. The aerofoil shape control cylinder 41 is maintained concentrically with two or more idler wheels 45 and supported by the idler wheels 45. Hydraulic supply and return pipes 46 power all elements of the entire system under the control of signals received from a cable. Situation feedback signals are also sent back by the cable. Computerized management of all control system elements, preferably utilizing AI, is one of the mechanisms that can be housed in an embedded module or mounted module 26 as appropriate.

[0133] Figure 15B discloses the installation of a shorter sail-directing cylinder 47 concentrically around the aerofoil shape control cylinder. The sail-directing cylinder is mounted on a rigid vertical mast and rotated in both directions by a concentrically held actuator supported by a plurality, preferably at least three, idler wheels.

[0134] Figure 16 discloses an example configuration in which a sail direction cylinder 47 holds a sail profile stretcher 48. An aerofoil tip shape profiler 49 is attached to a support arm 50 which includes a telescopic portion 50a. The support arm is attached to a trunnion held on the sail direction cylinder and slides through a bushing held in a spherical bearing 42.

[0135] Figure 17 shows the cross-section "AA" of Figure 16, and the same components disclosed in the plan view in Figure 16 are shown in elevation view.

[0136] It should be noted that the complete assemblies disclosed in Figures 15 to 17 can be installed in fine increments of altitude where a continuously variable sail configuration is deployed. In contrast, when rigid sail sections are deployed, one complete assembly can be attached, for example, to the base of each rigid sail section.

[0137] Figures 18A, 18B, and 18C exemplify details of three possible main shapes of the aerofoil portion in accordance with the description of Figure 14 above.

[0138] In one preferred configuration, the leading edge of the aerofoil section may consist of strong fibers attached to both the upper and lower surfaces of the aerofoil section, attached to a sail profile stretcher made of a thin, flexible material such as, but not limited to, steel, aluminum, plastic, or composite material. The aerofoil section may further include a sail profile stretcher that returns to the trailing edge as shown in Figure 18 and continues vertically across the entire surface of a continuously variable sail configuration or a rigid sail section. Alternatively, the rear portion of the aerofoil section may also consist of strong fibers, in which case additional mechanisms similar to those shown in Figures 16 and 17 for modifying the front body of the aerofoil section may be installed to change the shape of the rear body of the aerofoil section.

[0139] One example of an alternative preferred solution involves a sail profile stretcher that continues back to the trailing edge of the segment and is attached to an operating hinge at the very end in a manner similar to the flaps of an aircraft wing, as shown by the dotted line.

[0140] To rotate any sail in plan view as shown in Figure 14 without changing the shape of the aerofoil at any altitude, the actuators can be operated as a single unit so that there is no relative rotation between them. To change the shape of the aerofoil section, actuator 43 or actuator 53 is operated to create relative rotation between the aerofoil shape control cylinder and the sail direction cylinder. This relative rotation is shown in Figure 16 as moving the aerofoil tip shape profiler in both directions. To prevent wear of the flexible fibers that form the leading edge of the aerofoil section, the aerofoil tip shape profiler can be configured to rotate clockwise or counterclockwise. The flexible fibers can be accommodated by a telescopic section attached to a support arm.

[0141] If the control system requires so, an operating hinge may also be employed to further modify the shape of the airfoil section.

[0142] Figure 19 discloses some non-limiting examples of measures that can be taken to enhance the damage stability of the flywheel in any of the above configurations. Note that Figure 19 shows two different component parts of an annular flywheel in elevation views.

[0143] Figure 19 first discloses the fundamentally superior inherent damage stability of any flywheel, provided by the cellular structure forming a “double hull.” To allow air release, a gap is required between two separate surfaces. Further reinforcement can be obtained by extending selected radial cell walls 53 and circumferential cell walls 54 below deck level, but above the lower boundary of the air cushion forming the open cell circumferential and radial walls. When the air cushion is released into the atmosphere, the freeboard of the flywheel is reduced because, except for one or more cells that are opened to the atmosphere for any reason, the open cell circumferential and radial walls are submerged in the water and compressed to the point where the trapped air is restored to buoyancy equilibrium. Many air cushions in many unaffected cells provide adequate means to follow the action of waves sufficient to maintain a reduced but sufficient freeboard, and are designed to reduce damaging bending moments for a sufficiently long period of time for the damaged flywheel to recover to shallow water depths and make the necessary repairs.

[0144] By extending one or more circumferential cell 55 walls downward through the air cushion to the water below, further preservement in the event of damage can be provided. This isolates the loss of air cushion that would otherwise be lost to one or more annular rings unintentionally exposed to the atmosphere, limiting the resulting freeboard reduction in the damaged state. However, this comes at the cost of increased surface friction during operation.

[0145] Figure 19 shows that the inverted triangle symbol represents the water level in all figures, and that the head difference between the free water surface and the air cushion surface is head h.

[0146] Figure 20 shows two conceptual flywheel configurations, a closed circular configuration and an annular configuration, in plan view. Exemplary, non-restrictive open cell circumferential walls and open cell radial walls are shown, as described with reference to Figure 19.

[0147] Many further configurations are conceivable within the context of the above description. Two preferred but non-limiting examples are described with reference to Figures 21 to 23. Note that these configurations can be combined with any of the configurations described above. The examples shown in the figures are not limiting. For example, the flywheel configurations in Figures 21 and 22 can be implemented in place of one of the alternative flywheel structures in any of the above configurations, and / or any feature of those flywheels can be incorporated into the flywheel configuration described herein. Also, any of the power generation configurations described with reference to Figures 12 to 20 can be implemented with the flywheel configured as described below.

[0148] Figures 21 and 22 show a closed flywheel configuration in elevation and plan view, respectively. The flywheel 1 has an annular structure. However, the open center of the annule is closed by a cover 60. The form of the cover is not particularly limited. In the example configuration shown, the cover takes the form of a lightweight airtight disc. With the center of the annule closed, a single circumferential wall 3 can be provided. This contrasts with the annular structure described above. However, it should be noted that a cover like the one described here can be used with any of the annular flywheels described above, or with any other form of annular flywheel including a pair of circumferential walls 3, 4. The use of a single hanging circumferential wall 3 is preferred because it helps reduce surface friction drag from water.

[0149] The cover 60 may be in a cellular form. This enables a rigid, lightweight flywheel structure. The cellular cover may also be ballasted in accordance with the ballasting described above. A ballasted cover increases the energy storage capacity and, in some cases, increases the weight of the disc to more tightly balance the air pressure in the air cushion, keeping the cover relatively lightly stressed during operation. Alternative cover structures include, but are not limited to, a lightweight frame made of steel or other materials enclosed in an airtight outer shell of steel, concrete, glass-reinforced plastic, airtight fiber, or other suitable material.

[0150] By using a closed disc configuration in the annular flywheel in this way, the thickness of the air cushion can be significantly reduced, minimizing the depth of the hanging wall and the area of ​​its wetted surface.

[0151] The hanging circumferential wall may extend a considerable distance from the outer circumference of the annulus; that is, the circumferential wall may be shifted radially inward from the outer circumference of the flywheel. This is advantageous because it shortens the circumferential length, as shown in Figure 22, thereby reducing surface friction drag and maintaining sufficient hydrostatic stability. However, in an alternative configuration, the circumferential wall may be located on the outer circumference. The annulus and central disc are preferably made to remain above the water level by a distance sufficient to minimize the impact of waves.

[0152] Figure 23 shows a third preferred example C of the rigging configuration of Figure 12. This configuration addresses the observation that the spacing between masts can actually be much narrower than illustrated in Figure 13, resulting in the diagonal rigging for each mast overlapping with the diagonal rigging of several adjacent masts to form a cable cluster, potentially casting a wake shadow on the sail and thereby limiting the sail's aerodynamic performance to some extent. The number of diagonal rigging legs can be dramatically reduced, as shown in Figure 23, by arranging the masts in several rows at different radii and supporting them circumferentially and laterally with horizontal rigging. The corresponding increase in total horizontal rigging is far less than the reduction in diagonal rigging, thereby achieving reductions in both drag and cost. As will be readily apparent to those skilled in the art, many alternative mast and / or rigging configurations are also possible.

[0153] Furthermore, in the configuration shown in Figure 23, the horizontal rigging casts a shadow of wake forming a horizontal disk at the level of the joint between adjacent vertical sails, which causes little damage to the airflow profile across the sails and thereby improves performance. Because the extent to which one complete horizontal pattern of rigging exists within a common turbulent wake is greater than that of diagonal rigging, the cables at each horizontal rigging level also generate less drag per unit length than the diagonal rigging.

[0154] The mast is shown to extend from the outer circumference of the ring by a distance W. The distance W is selected to be sufficiently large to give the diagonal rigging a practical geometry. Further increasing W reduces the number of masts that can be installed, thereby reducing the lever arm of the sail's lift around the vertical axis of the flywheel. As those skilled in the art will see, an appropriate balance will be struck based on the specific implementation configuration.

[0155] Referring to Figure 24, a partial cross-sectional view of the configuration of a device including an alternative fluid seal, particularly suitable for use in an onshore configuration, is shown. The fluid seal includes a segmented labyrinth. In this configuration, the labyrinth is formed by a plurality of interconnected cells, each cell being formed by a hanging wall 70 hanging down from the flywheel 1 and a facing wall 71 projecting from the opposite side of the hanging wall 70. In the configuration shown, there are four interconnected cells. It should be understood that alternative configurations may have more or fewer interconnected cells. As can be seen in Figure 24, each interconnected cell results in a head difference K in the water or other fluid F trapped between the walls 70, 71. A head difference equal to the pressure head in the air cushion is cumulatively formed. In Figure 24, where there are four cells, the air cushion head is equal to 4K. The walls 70, 71 extend circumferentially. As will be readily apparent to those skilled in the art, the walls 70, 71 are not particularly limited in terms of material or form. The hanging wall 70 is shown hanging down from the circumferential wall 3 of the flywheel 1, but in an alternative configuration, the circumferential wall 3 may be omitted, and the hanging wall 70 may be directly attached to the underside 82 of the deck 5. The wall 71 can be attached to a suitable base 72, which may be concrete or other material. The fluid F in the labyrinth seal confines the gas within the opening 2 to define an air cushion. The flywheel 1 can incorporate any combination of any of the flywheel features described above. In a preferred example, the flywheel may be an annular ring with a cover, such as the flywheel 1 described with reference to Figure 21. Of course, it may be formed in other ways.

[0156] Figure 24 further shows an optional fluid injection port indicated by arrow 80, which can be optionally positioned at appropriate points on the outer perimeter of the maze for fluid injection into all or selected cells of the sealed maze to provide a desired operational function, including but not limited to the following: • Maintain the optimal head difference K in each cell by pumping water into or out of the selected maze cells. • Maintain the optimal head difference K in each cell by pumping or releasing compressed air into the selected maze cells. • Discharging excess hot water generated by fluid friction from selected labyrinth cells and replacing it with cold water. • Inject fluid friction-reducing chemicals into the water within the selected maze cells. In the alternative configuration, the fluid injection port 80 may be omitted.

[0157] Figure 24 further shows an optional magnetic levitation ("MAGLEV") unit 81, which, as will be apparent to those skilled in the art, can provide desirable operating functions including, but not limited to, the following: • Converting electrical energy input into stored mechanical energy through induced tangential torque. Conversely, it is the process of converting stored rotating mechanical energy into electrical energy output through induced tangential torque. • Provide additional vertical support assistance through the air cushion. • To facilitate construction within practical tolerances, the vertical and horizontal positions of the entire flywheel assembly must be kept within sufficiently strict limits. • Limit the tendency for the entire flywheel assembly to exhibit resonant vibrations.

[0158] It should be understood that the illustrated configuration of the MAGLEV unit 81 is only a schematic diagram and should not be interpreted as limiting. The MAGLEV unit 81 can take any suitable form, as will be readily apparent to those skilled in the art. The illustrated inverted "V" shape of the interface between the rotating upper and stationary lower is just one of many optional configurations that provide both vertical and horizontal support and alignment. Other such optional configurations include, but are not limited to, separate vertical and horizontal MAGLEV units, or configurations in which one of these separate units is a MAGLEV unit and the other is a conventional mechanical structure, diagonal interfaces forming a large conical or inverted conical frustum around the entire outer circumference of the MAGLEV unit 81, upright "V" shapes, "W" or "M" shapes.

[0159] Those skilled in the art will understand that the MAGLEV unit 81 may be omitted, or may even be incorporated into an alternative configuration that omits the labyrinth sealing.

[0160] As used herein and in the claims, the terms “comprises” and “comprising” and their variations mean that the specified features, steps, or integers are included. These terms should not be construed as excluding the existence of other features, steps, or components.

[0161] The features disclosed in the above description or the following claims or accompanying drawings, as appropriate, in a specific form, by means of performing the disclosed functions, or by methods or processes for obtaining the disclosed results, can be used separately or in any combination of such features to realize the present invention in its various forms.

[0162] While specific exemplary embodiments of the present invention have been described, the appended claims are not intended to be limited to these embodiments only. The claims should be interpreted literally, as intended, and / or to encompass equivalents.

Claims

1. A power generating and / or power storage device including a floating flywheel, wherein the flywheel is configured to contact a liquid area for rotation about a substantially vertical axis during use, the underside of the flywheel includes a circumferentially extending opening, and during use, gas is confined within the opening by the surface of the liquid to define a gas cushion for supporting the flywheel. The flywheel has a cellular structure composed of multiple cells, A power generation and / or power storage device further comprising a ballast system including one or more valves, wherein the ballast system is configured to control the injection and discharge of the liquid from the cell.

2. The apparatus according to claim 1, wherein the circumferential opening extends substantially continuously around the entire circumference of the flywheel.

3. The apparatus according to claim 1 or 2, wherein the flywheel is substantially annular.

4. The apparatus according to claim 3, comprising an airtight cover that closes the center of the ring.

5. The apparatus according to claim 4, wherein the cover includes a frame closed by a cellular disc or an outer shell which may include steel, concrete, glass-reinforced plastic or airtight fibers.

6. The apparatus according to claim 4, wherein the cover closes the opening.

7. The apparatus according to claim 1 or 2, wherein the flywheel includes a pair of spaced-apart circumferential walls that hang down from the flywheel when in use, and the opening is provided between the walls.

8. The apparatus according to claim 7, wherein one of the circumferential walls is an outer peripheral wall.

9. The apparatus according to claim 1 or 2, wherein the flywheel includes a single circumferential wall that hangs down from the flywheel when in use, and the opening is provided by the circumferential wall.

10. The circumferential wall is provided on the outer circumference of the flywheel, or the flywheel The apparatus according to claim 9, wherein the components are arranged at intervals on the radially inward side of the outer circumference.

11. The apparatus according to claim 4, wherein a single circumferential wall hanging down from the flywheel during use penetrates the surface of the liquid during use.

12. The apparatus according to claim 4, wherein a single circumferential wall hanging down from the flywheel during use hangs substantially vertically during use.

13. The apparatus according to claim 7, wherein the opening is completely or partially closed by the wall and a deck from which the wall hangs down, and the deck is substantially parallel to the surface of the liquid when in use.

14. The opening is completely or partially closed by the wall and the deck from which the wall hangs down. The flywheel is substantially annular, (1) The deck, The apparatus according to claim 1, wherein one or more or all of the following have a cellular structure: (2) a single circumferential wall hanging down from the flywheel when in use, and (3) an airtight cover that closes the center of the ring.

15. The apparatus according to claim 1, wherein the ballast system further includes a pump for pumping the liquid into the cells and / or pumping the water out of the cells.

16. The apparatus according to claim 1 or 2, comprising one or more compressors for supplying air to the opening.

17. The apparatus according to claim 1 or 2, comprising one or more sails attached to the flywheel.

18. The apparatus according to claim 17, wherein the sail extends substantially around the entire circumference of the flywheel.

19. The apparatus according to claim 17, wherein the sail is rigid or flexible.

20. The apparatus according to claim 17, wherein a control system is provided to change the direction of the sail with respect to the wind direction as the flywheel rotates.

21. The apparatus according to claim 17, wherein the sail is attached to a mast, the mast is freestanding or supported by a support extending between the masts, the support includes rigging, and the sail and rigging are configured to be laid flat.

22. The apparatus according to claim 17, wherein two or more arrays of sails extending in the circumferential direction are provided, spaced apart in the radial direction.

23. The apparatus according to claim 1 or 2, wherein the flywheel has a diameter of 1,500 meters or more.

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