Inverted pendulum type wave energy conversion device

Abstract

An inverted pendulum wave energy converter for floating structures, boats, and ships is disclosed. The device comprises an inverted pendulum structure having an inertia moment changing system and an energy conversion connection system connecting the inverted pendulum structure to a host vessel. The ability to control the inertia moment of the inverted pendulum structure with respect to the oscillation axis of the host vessel sufficiently minimizes the risk of capsizing in survival mode, maximizes the conversion of wave energy to electricity, and minimizes the oscillation amplitude of the host vessel. In boats and ships, the inverted pendulum structure is equipped with a wind-assisted propulsion system that maximizes the efficiency of clean energy recovery.

Description

Technical Field

[0001] The present invention relates to an inverted pendulum type wave energy conversion device installed on a floating structure, a boat, and a ship, which converts wave energy into electrical energy and reduces the swing amplitude.

Background Art

[0002] The host vessel may be a floating structure, a boat, or a ship. Such a host vessel absorbs wave energy and converts it into rocking energy. To convert this rocking energy, that is, a part of the wave energy, into electrical energy, a rocking oscillator device is installed on the host vessel (Yong Ma, Shan Ai, Lele Yang, Aiming Zhang, Sen Liu, Binghao Zhou; Research on design and optimization of the pitching float wave energy converter; July 2020). Such an oscillator type wave energy conversion device includes an oscillator structure and an energy conversion connection mechanism that connects the oscillator structure to the host vessel. Usually, the oscillator structure is a rod having a concentrated mass at one end and connected to the host vessel via an energy conversion connection mechanism at the other end. In recent years, various energy conversion connection mechanisms for converting kinetic energy into electrical energy have been developed, which may be hydraulic, electromagnetic, or mechanical, but other technologies are also available. Similar systems are widely used in other fields of engineering, such as the suspension of automobiles. Usually, by controlling the stiffness and damping of the energy conversion connection mechanism so that the dynamic motion of the oscillator structure is controlled, the wave energy conversion during operation is maximized.

[0003] However, such pendulum-type wave energy conversion devices have a drawback: the moment of inertia of the pendulum structure around the host vessel's oscillation axis is extremely small compared to the mass of the pendulum structure. This is because the center of gravity of the pendulum structure is close to the host vessel's oscillation axis. As a result, even to convert a relatively small amount of wave energy into electrical energy and slightly reduce the oscillation amplitude of the host vessel, a very heavy pendulum structure is required, which is not economically practical.

[0004] An improved wave energy converter is one in which the pendulum structure is replaced with an inverted pendulum structure (Jinming Wu, Chen Qian, Siming Zheng, Ni Chen, Dan Xia, Malin Goeteman; Investigation on the wave energy converter that reacts against an internal inverted pendulum; Volume 247, May 15, 2022, 123493, ELSEVIER). In these devices, the center of gravity of the inverted pendulum structure is far from the oscillation axis of the host vessel. Therefore, during operation, such an inverted pendulum structure can obtain a very large moment of inertia relative to its mass, and as a result, the conversion of wave energy and reduction of oscillation amplitude can be economically feasible. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] European Patent Application Publication No. 2738925 [Patent Document 2] German Utility Model No. 212013000254 Specification [Overview of the project] [Problems that the invention aims to solve]

[0006] However, such inverted pendulum-type wave energy conversion devices also have drawbacks. Specifically, in emergencies where the energy conversion connection mechanism fails and stops due to very rough seas, or in survival mode with extremely high waves, the inverted pendulum structure may overturn the host vessel. Furthermore, under conditions where the host vessel's oscillation is quite irregular (chaotic), in order to improve the efficiency of wave energy conversion, it is desirable to have the ability to control more parameters of dynamic motion, in addition to the ability to control the stiffness and damping of the energy conversion connection mechanism. Further improved wave energy conversion devices are published in European Patent Application Publication No. 2738925 (Okayama University, National University Corporation [Japan]; Mitsui Engineering & Shipbuilding Engineering [Japan], published June 4, 2014) and German Utility Model No. 212013000254 (Man Mei Chan [China], published July 17, 2015). In particular, the latter patent (German Utility Model No. 212013000254) solves the above problem and can be considered the current technology in the art. Furthermore, this document discloses an inverted pendulum wave energy conversion device comprising an inverted pendulum structure and an energy conversion connection system connecting the inverted pendulum structure to a host vessel, characterized in that the inverted pendulum structure is equipped with an inertia moment changing system. Although these state-of-the-art devices have many advantages, In order to make various inverted pendulum-type wave energy conversion devices more economically practical, especially in boats and ships, it is desirable to combine them with wind energy systems.

[0007] The object of the present invention is to provide an inverted pendulum wave energy converter in which the inverted pendulum structure is safe for the host vessel in emergency or survival mode, more parameters of dynamic motion can be controlled during operation, and part of the device can be combined with a wind energy system.

[0008] According to the present invention, It has a moment of inertia changing system. The inverted pendulum structure and the energy conversion connection mechanism that connects the inverted pendulum structure to the host vessel are provided, and the inverted pendulum structure Wind-powered propulsion system An inverted pendulum type characterized by having ocean A wave energy conversion device is provided. The host vessel may be a floating structure, a boat, or a ship. During operation, the moment of inertia changing system can change the moment of inertia of the inverted pendulum structure with respect to the oscillation axis of the host vessel by, firstly, increasing or decreasing the mass of the inverted pendulum structure; secondly, increasing or decreasing the vertical distance between the center of gravity of the inverted pendulum structure and the oscillation axis of the host vessel; or thirdly, by a combination of these two methods.

[0009] The moment of inertia changing system may include a folding mechanism that can raise or lower the center of gravity of the inverted pendulum structure. This folding mechanism allows the inverted pendulum structure to be folded in a short time.

[0010] The inverted pendulum structure may include a water tank, and the moment of inertia changing system may include a water supply and drainage system. Furthermore, the moment of inertia changing system may further include an emergency drainage door that allows for quick drainage from the water tank.

[0011] The inverted pendulum structure may include a columnar body and a main body connected to the columnar body. The moment of inertia changing system may include a guide connection between the columnar body and the main body, and a motor mechanism that can move the main body up and down along the columnar body. Furthermore, the moment of inertia changing system may further include an emergency decoupling mechanism that can decouple the motor mechanism to lower the main body in a short time.

[0012] If the host vessel is a boat or ship, the energy conversion connection mechanism may include a yaw rotation mechanism that can rotate the wind-assisted propulsion system. The wind-assisted propulsion system may include one or more rotor sail mechanisms (Flettner rotors), rigid-wing sail mechanisms, soft-wing sail mechanisms, flexible sail mechanisms, or ventilated foil mechanisms.

[0013] The inverted pendulum wave energy conversion device according to the present invention has many advantages. In emergency or survival mode, the moment of inertia modification system reduces the moment of inertia of the inverted pendulum structure with respect to the oscillation axis of the host vessel to an extremely small size in a short time, thereby sufficiently reducing the adverse effects of the inverted pendulum structure on the stability of the host vessel. Furthermore, the moment of inertia of the inverted pendulum structure with respect to the oscillation axis of the host vessel is an important dynamical parameter, and therefore, having the ability to control this moment of inertia during operation, in addition to the ability to control the stiffness and damping of the energy conversion connection mechanism, enables maximization of wave energy conversion efficiency and minimization of the oscillation amplitude of the host vessel. In addition, the inverted pendulum structure is equipped with a wind-assisted propulsion system. We In the apparatus of the present invention, wave energy technology and wind energy technology are combined. doing Such integrated clean energy devices are highly efficient and therefore extremely attractive from an economic standpoint, making them particularly suitable for installation on boats and ships. [Brief explanation of the drawing]

[0014] Some preferred embodiments of the present invention will be described below by reference only to the accompanying drawings.

[0015] [Figure 1] Figure 1 shows a cross-sectional view of a vessel equipped with an inverted pendulum-type wave energy converter according to one embodiment of the present invention. In this figure, the sea surface is choppy, the vessel maintains a vertical attitude, the inverted pendulum-type wave energy converter is not operating, and therefore the device is also positioned vertically. Note that the wind-assisted propulsion system is not shown.

[0016] [Figure 2]FIG. 2 is a cross-sectional view of a ship equipped with the inverted pendulum type wave power energy conversion device according to the embodiment of the present invention shown in FIG. 1, showing the state during operation, that is, when the ship is rolling and the device is swinging. On the wavy sea surface, the ship has a random rolling angle with respect to the vertical direction, and the inverted pendulum type wave power energy conversion device is in operation. Therefore, the angle of the device with respect to the vertical is generally different from the angle of the ship with respect to the vertical. Note that the wind power assist propulsion system is not shown.

[0017] [Figure 3] FIG. 3 shows a longitudinal sectional view of a ship equipped with the inverted pendulum type wave power energy conversion device according to the embodiment of the present invention shown in FIGS. 1 and 2. Here, the inverted pendulum structure is shown in a folded state on the ship deck. On the wavy sea surface, the ship is shown in a state of maintaining its posture in the vertical direction. Note that the wind power assist propulsion system is not shown.

[0018] [Figure 4] FIG. 4 shows a cross-sectional view of a ship equipped with the inverted pendulum type wave power energy conversion device according to another embodiment of the present invention. On the wavy sea surface, the ship is in a state of maintaining its posture in the vertical direction, and the inverted pendulum type wave power energy conversion device is not in operation. Therefore, the device is also located in the vertical direction. Note that the wind power assist propulsion system is not shown.

[0019] [Figure 5] FIG. 5 shows a cross-sectional view of a ship equipped with the inverted pendulum type wave power energy conversion device according to the embodiment of the present invention shown in FIGS. 1 to 3. The inverted pendulum structure includes a rotor sail mechanism (Flettner rotor). On the wavy sea surface, the ship is shown in a state of maintaining its posture in the vertical direction, and the inverted pendulum type wave power energy conversion device is not in operation. Therefore, the device is also located in the vertical direction.

Embodiments for Carrying Out the Invention

[0020] (The wind-powered propulsion system is not shown.)According to the preferred embodiment of the present invention shown in FIG. 1, the host vessel is a ship 1, and the inverted pendulum structure includes a cylindrical water tank 2 that is perpendicular to the ship deck when the inverted pendulum type wave power energy conversion device is not operating. The energy conversion connection mechanism includes a hydraulic connection mechanism 3 that connects the circular bottom of the cylindrical water tank 2 to the ship 1.

[0021] Examples of the hydraulic connection mechanism 3 include a hydraulic piston cylinder, a hydraulic accumulator, a hydraulic motor - generator system, and a mechanical hinge support. During operation, the spring stiffness constant is actively controlled by a small electric motor - hydraulic pump system, and the damping coefficient is actively controlled by controlling the conversion output. There can also be many other known hydraulic or non - hydraulic configurations as the energy conversion connection mechanism. The moment of inertia change system includes a water supply and drainage system. Examples of this water supply and drainage system include a control electric motor - hydraulic pump system, valves, and a PLC.

[0022] Furthermore, the moment of inertia change system further includes an emergency drainage door that can drain water from the cylindrical water tank 2 in an extremely short time. (The wind-powered propulsion system is not shown.) During operation as shown in FIG. 2, in an emergency, for example, when the rolling angle of the ship exceeds its threshold value, the water supply and drainage system and the emergency drainage door drain water from the cylindrical water tank 2 in an extremely short time. As a result, the mass of the cylindrical water tank 2, and thus the moment of inertia of the cylindrical water tank 2 about the rocking axis of the ship 1, is reduced. Consequently, the adverse effect of the cylindrical water tank 2 on the stability of the ship 1 is sufficiently minimized.

[0023] Furthermore, by having the ability to change the mass of water, and thus the moment of inertia of the cylindrical water tank 2 about the rocking axis of the ship 1, the ability to control the dynamic motion during operation is improved, thereby maximizing the wave power energy to be converted and minimizing the rocking amplitude of the ship. Also, the moment of inertia change system further includes a folding mechanism. This folding mechanism includes a hinge - actuator system provided at the bottom of the cylindrical water tank 2, (The wind-powered propulsion system is not shown.)As shown in Figure 3, this makes it possible to rotate the cylindrical water tank 2 and lay it on its side on the ship's deck.

[0024] By rotating an empty cylindrical water tank, for example, between a vertical and a tilted position, the vertical distance between the center of gravity of the cylindrical water tank and the pivot axis of the vessel 1 changes, and therefore the moment of inertia of the cylindrical water tank relative to the pivot axis of the vessel 1 also changes. Thus, this rotational motion can be used to further control the moment of inertia of the cylindrical water tank relative to the pivot axis of the vessel 1. As a result, enhanced moment of inertia control can be used in emergency situations to reduce the amplitude of the vessel's rocking motion and to maximize the efficiency of wave energy conversion. The wind-powered propulsion system includes a rotor sail mechanism (Flettner rotor) 6, as shown in Figure 5. The resulting clean energy device is highly efficient and therefore extremely attractive from an economic standpoint. Generally, the wind-powered propulsion system includes one or more mechanisms: a rotor sail mechanism (Flettner rotor) 6, a rigid-wing sail mechanism, a soft-wing sail mechanism, a flexible sail mechanism, or a ventilated foil mechanism. If the wind-powered propulsion system requires yaw rotation, the energy conversion connection system further includes a yaw rotation mechanism.

[0025] (The wind-powered propulsion system is not shown.) According to another preferred embodiment of the present invention shown in Figure 4, the host vessel is a ship 1, and the inverted pendulum structure includes a steel columnar body 4 that is perpendicular to the ship's deck when the inverted pendulum wave energy converter is not operating, and a water tank 5 connected to the steel columnar body 4. The energy conversion connection system includes a hydraulic connection system 3 that connects the base of the steel columnar body to the ship 1.

[0026] The energy conversion connection system is identical to that of the first embodiment. The moment of inertia change system includes all three elements included in the first embodiment: the water supply and drainage system, the emergency drainage door, and the folding mechanism.

[0027] Furthermore, the moment of inertia changing system further includes a guide connection between the steel columnar body 4 and the water tank 5, and a motor mechanism that can move the water tank 5 up and down along the steel columnar body 4. During operation, the vertical movement of the water tank 5 changes the vertical distance between the center of gravity of the inverted pendulum structure and the pivot axis of the ship 1, so the moment of inertia of the inverted pendulum structure with respect to the pivot axis of the ship 1 can be further controlled by controlling this vertical movement.

[0028] This enhanced moment of inertia control maximizes wave energy conversion efficiency and minimizes the ship's oscillation amplitude. Furthermore, the moment of inertia changing system includes an emergency decoupling mechanism that can decouple the motor mechanism and lower the water tank 5 along the steel columnar body 4 in the event of motor mechanism failure and shutdown. This minimizes the adverse effects of the inverted pendulum structure on the stability of the ship 1.

[0029] The inverted pendulum structure is further equipped with a wind-assisted propulsion system. The resulting clean energy device is highly attractive from an economic standpoint due to its high efficiency. Generally, the wind-assisted propulsion system includes one or more mechanisms: a rotor sail mechanism (Flettner rotor) 6, a rigid-wing sail mechanism, a soft-wing sail mechanism, a flexible sail mechanism, or a ventilated foil mechanism. If yaw rotation is required for the wind-assisted propulsion system, the energy conversion connection system further includes a yaw rotation mechanism.

[0030] Although the present invention has been described in relation to the preferred embodiments described above, it should be understood that many other modifications and variations are possible without departing from the scope of the invention. Accordingly, the appended claims are understood to encompass such modifications and variations that fall within the true scope of the invention. Some embodiments of the present invention are described in the following sections [1]-

[13] .

[0031] [Item 1] An inverted pendulum type wave energy conversion device, An inverted pendulum structure, The inverted pendulum structure is connected to an energy conversion connection mechanism that is connected to a host vessel, Includes, The inverted pendulum structure is characterized by including an inertia moment changing system. Inverted pendulum type wave energy conversion device. [Item 2] The inverted pendulum type wave energy conversion device according to item 1, characterized in that the moment of inertia changing system includes a folding mechanism that can raise or lower the center of gravity of the inverted pendulum structure. [Item 3] The inverted pendulum structure includes a water tank, The inertia moment changing system is characterized by including a water supply and drainage system. An inverted pendulum type wave energy conversion device as described in item 1. [Item 4] The inverted pendulum wave energy converter according to item 3, characterized in that the moment of inertia changing system further includes an emergency drainage door. [Item 5] The inverted pendulum structure includes a columnar body and a main body connected to the columnar body, The moment of inertia changing system is characterized by including a guide connection portion between the columnar body and the main body, and a motor mechanism that can move the main body up and down along the columnar body. An inverted pendulum type wave energy conversion device as described in item 1. [Item 6] The inverted pendulum wave energy converter according to item 5, characterized in that the moment of inertia changing system further includes an emergency decoupling mechanism capable of decoupling the motor mechanism. [Item 7] The inverted pendulum type wave energy conversion device according to item 1, characterized in that the energy conversion connection mechanism includes a yaw rotation mechanism. [Item 8] The inverted pendulum wave energy conversion device according to item 1, characterized in that the inverted pendulum structure includes a wind-assisted propulsion system. [Item 9] The inverted pendulum type wave energy conversion device according to item 8, characterized in that the wind-assisted propulsion system includes a rotor sail mechanism (Fretner rotor). [Item 10] The inverted pendulum type wave energy conversion device according to item 8, characterized in that the wind-assisted propulsion system includes a rigid-wing sail mechanism. [Item 11] The inverted pendulum type wave energy conversion device according to item 8, characterized in that the wind-assisted propulsion system includes a soft-wing sail mechanism. [Item 12] The inverted pendulum type wave energy conversion device according to item 8, characterized in that the wind-assisted propulsion system includes a soft sail mechanism. [Item 13] The inverted pendulum type wave energy conversion device according to item 8, characterized in that the wind-assisted propulsion system includes a ventilation foil mechanism.

Claims

1. An inverted pendulum type wave energy conversion device, An inverted pendulum structure, The inverted pendulum structure is connected to an energy conversion connection mechanism that is connected to a host vessel, Includes, The inverted pendulum structure is characterized by including an inertia moment changing system. Inverted pendulum type wave energy conversion device.

2. The inverted pendulum type wave energy conversion device according to claim 1, characterized in that the moment of inertia changing system includes a folding mechanism that can raise or lower the center of gravity of the inverted pendulum structure.

3. The inverted pendulum structure includes a water tank, The inertia moment changing system is characterized by including a water supply and drainage system. The inverted pendulum type wave energy conversion device according to claim 1.

4. The inverted pendulum type wave energy conversion device according to claim 3, characterized in that the moment of inertia changing system further includes an emergency drainage door.

5. The inverted pendulum structure includes a columnar body and a main body connected to the columnar body, The moment of inertia changing system is characterized by including a guide connection portion between the columnar body and the main body, and a motor mechanism that can move the main body up and down along the columnar body. The inverted pendulum type wave energy conversion device according to claim 1.

6. The inverted pendulum type wave energy conversion device according to claim 5, characterized in that the moment of inertia changing system further includes an emergency decoupling mechanism capable of decoupling the motor mechanism.

7. The inverted pendulum type wave energy conversion device according to claim 1, characterized in that the energy conversion connection mechanism includes a yaw rotation mechanism.

8. The inverted pendulum wave energy conversion device according to claim 1, characterized in that the inverted pendulum structure includes a wind-assisted propulsion system.

9. The inverted pendulum type wave energy conversion device according to claim 8, characterized in that the wind-assisted propulsion system includes a rotor sail mechanism (Flettner rotor).

10. The inverted pendulum type wave energy conversion device according to claim 8, characterized in that the wind-assisted propulsion system includes a rigid-wing sail mechanism.

11. The inverted pendulum type wave energy conversion device according to claim 8, characterized in that the wind-assisted propulsion system includes a soft-wing sail mechanism.

12. The inverted pendulum type wave energy conversion device according to claim 8, characterized in that the wind-assisted propulsion system includes a soft sail mechanism.

13. The inverted pendulum type wave energy conversion device according to claim 8, characterized in that the wind-assisted propulsion system includes a ventilation foil mechanism.

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