Floating wave power generation device and power generation method

Abstract

A floating wave power generation device that can be easily installed on the sea and can obtain high power generation efficiency is provided. [Solution] This is a floating wave power generation device that floats on the sea surface, comprising a floating body with a wave inlet, a rotating body with multiple wave receiving blades that rotate 360 ​​degrees around a specific rotation axis fixed to the floating body and rotates by receiving waves flowing in from the wave inlet with the multiple wave receiving blades, a generator attached to the rotating axis, and mooring members that moor the floating body to the seabed in a state where it can float on the sea surface.

Description

[Technical field]

[0001] The present invention relates to a wave power generation device that is installed on a floating structure and generates power by using the force of waves that are received by a wave receiving plate attached to a rotating shaft, and a power generation method thereof. [Background technology]

[0002] Ocean energy, a type of natural energy, originates from thermal energy from the sun, the movement of the atmosphere caused by the distribution of thermal energy in the atmosphere, and the movement of seawater caused by thermal energy in the ocean, among other interactions. The main methods of generating electricity using ocean energy include power generation using the power of waves, power generation using tidal and ocean currents, and power generation using ocean temperature differences. Wave power generation using the power of waves includes the oscillating water column type, the movable object type, and the wave overtopping type.

[0003] An example of the configuration of the oscillating water column type is shown in Figure 10. A floating object 113 is attached to a pillar 111 that is fixedly installed or moored to the seabed 19. The floating object 111 is structured so that it can operate in accordance with changes in the sea level. The floating object 113 receives the up and down movement of the sea surface caused by waves generated on the sea surface, and the change in its relative position with the pillar 111 is converted into energy to generate electricity.

[0004] An example of the configuration of the movable object type is shown in Figure 11. A movable object 127 that can move around a rotation axis 125 installed on a breakwater 121, offshore structure 123, or the like on the seabed 19 is installed. The movable object 127 vibrates around the rotation axis due to the horizontal or vertical components of the force of waves generated on the sea surface. This structure converts the force of the vibration into energy to generate electricity.

[0005] An example of the configuration of the wave overtopping type is shown in Figure 12. A wave overtopping plate 133 is installed on a breakwater 131 or the like on the seabed 19 so that the water level is lower than the highest water level of the waves, and an overtopping water storage space 135 for storing seawater from overtopping waves is provided between the wave overtopping plate 133 and the breakwater. A water channel 137 is provided midway between the wave overtopping water storage space 135 and the wave overtopping plate. The wave overtopping plate 133 and the overtopping seawater are stored in the wave overtopping water storage space 135. When the water level on the sea surface side of the wave overtopping pillar 133 becomes lower than the water level stored in the wave overtopping storage space 135, the plate 133 is released. At that time, the structure converts the kinetic energy, which is the potential energy of the water flow provided in the water channel 137, into electricity to generate power. In addition, in areas where there are constant water currents (tidal currents, ocean currents) in the seawater, there are structures in which a propeller-type rotating body is installed on the seabed and the kinetic energy of the moving seawater is converted into energy for the rotating body to generate electricity. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2024-20118 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention is a wave power generation device that generates electricity using the force of waves received by a wave receiving plate attached to a rotating shaft installed on a floating structure, and is characterized in that the wave power generation device comprises a rotating shaft installed on the floating structure, which can rotate 360 ​​degrees around the rotating shaft, four or more wave receiving plates of the same length radially arranged about the rotating shaft, and a generator that extracts rotational energy attached to the rotating shaft, which extracts the energy of seawater waves received by the wave receiving plate as rotational energy of a rotating shaft installed perpendicular to the direction of wave travel and converts the rotational energy into electrical energy.

[0008] The kinetic energy of seawater generated in the ocean consists of kinetic energy caused by ocean currents and tides, which have a certain directionality, and wave energy, which is the vertical and horizontal kinetic energy of the water surface rotating with a certain period. If there are no ocean currents or tides and the water is deep enough, the vertical and horizontal kinetic energy will be the same. In addition, where waves come into contact with the coast, the horizontal energy of the waves is reflected by breakwaters, etc., so a method is used to convert the vertical kinetic energy of the waves into electrical energy.

[0009] Ocean currents and tides are dominant far from the coast, so electricity is often generated using a rotating body installed on the ocean floor in deep water, which requires very large equipment. In ocean areas far from the coast, there is a method of generating electricity by using a generator capable of deforming to match the swell of the waves, which can deform to a size equal to or larger than the wavelength of the waves (several meters), but even in this case, the size must be about the wavelength of the waves, making it very large. On the other hand, because waves are high near land such as coasts and breakwaters, power generation is often achieved by the movement of oscillating water columns or movable objects installed on coasts, breakwaters, or in close proximity to them. When installed on coasts or breakwaters, the locations for installing the power generation equipment already exist, so there is an advantage in that the initial cost of the equipment can be reduced, as there is no need to build new structures. However, coasts and breakwaters are already in use, and in places where the wave energy is high and suitable for wave power generation, wave-dissipating blocks and the like are installed to prevent erosion by waves, so there are limited locations where power generation equipment can be installed next to coasts or breakwaters. Wave power generation is thought to be a substitute for wave-dissipating blocks because it absorbs wave energy and extracts it as electrical energy, but when waves larger than the rated capacity arrive, power generation is often stopped to prevent damage to the power generation equipment, making it difficult to use as a substitute. In other words, it would be too large to install far from the coast, and installation locations would be limited if it were to be installed close to the coast or a breakwater.

[0010] For these reasons, it is expected that the freedom to install wave power generation equipment would be expanded if there were a wave power generation system that could be installed in coastal areas a short distance away from the shore or breakwaters, which would expand the options for installation locations. When installing in coastal areas some distance from the shore or breakwaters, there are three major challenges.

[0011] First, the power generation equipment needs to be installed in water of a certain depth. But in locations suitable for wave power generation, the waves are relatively large, which limits the period during which construction is possible. In addition, the power generation equipment needs to be able to withstand the force of the waves, so a structurally strong design is required and the construction work to secure it to the seabed is extensive.

[0012] Secondly, when wave energy is transmitted from the deep sea to the coast or breakwater, the waves in the deep sea form waves by periodically rotating vertical and horizontal energy. When the wave energy is transmitted toward the coast or the coastal part of the breakwater, the influence of the seabed appears when the water depth reaches about the wavelength of the wave. As the water depth becomes shallower, the cross-sectional area of ​​the wave in the direction of travel gradually decreases, so part of the periodically rotating energy of the wave is converted into group velocity component energy that has a velocity component in the direction of travel. When the wave has a group velocity component, the periodicity of the wave changes. As the periodicity of the wave is disturbed, the power generation efficiency decreases in power generation methods that utilize the periodicity in the vertical and horizontal directions. In order to suppress the group velocity component and ensure the periodicity of the wave, a method is being considered to create an ideal situation by using a caisson or fixed structure in three directions or one direction of the power generation equipment to cancel the non-periodic component of the wave at the place where the power generation equipment receives the wave energy through resonance phenomena. In this case, an ideal situation can be created when the designed specific wavelength has a constant period over the long term; however, in order to create ideal wave conditions by canceling out the incident energy and reflected energy in terms of the group velocity components of the waves, energy that would contribute to power generation is consumed as heat.

[0013] Third, ocean wave periods are statistically distributed with a certain peak (e.g., 8 or 12 seconds), but are irregular in terms of amplitude and phase. When the waves are calm and the wave height is low, the waves may be continuous and periodic, but when the wave amplitude increases and the wave conditions are suitable for wave power generation, the waves become irregular, with multiple individual waves overlapping. When multiple waves overlap, the phase of the succeeding wave changes suddenly relative to the previous wave. In power generation methods that utilize vertical and horizontal periodicity, the sudden change in phase causes a jump in the periodicity, disrupting the synchronization and resonance states and reducing power generation efficiency.

[0014] The present invention has been made in consideration of the above circumstances, and its object is to provide a floating wave power generation device and a power generation method that can be easily installed at sea and can obtain high power generation efficiency. [Means for solving the problem]

[0015] The present invention is a floating wave power generation device that floats on the sea surface, comprising a floating body with a wave inlet, a rotating body having a plurality of wave receiving blades that rotate 360 ​​degrees around a predetermined rotation axis fixed to the floating body and that rotates by receiving waves flowing in from the wave inlet with the plurality of wave receiving blades, a generator attached to the rotating axis, and mooring members that moor the floating body to the seabed in a state where it can float on the sea surface. Preferably, the mooring members moor the floating body such that the floating body is located at a mounting position at a mean water level shallower than half the mean wavelength of the waves.

[0016] Preferably, the mooring member moors the floating body so that the floating body is located at the installation position where the average group velocity of waves is greater than 1 / 8 of the wavelength of the waves.

[0017] Preferably, the mooring member moors the floating body so that the floating body is positioned at the installation position where the rotation axis is located above the average waterline of the floating body and the longitudinal direction of the rotation axis is approximately perpendicular to the average direction of travel of waves on the sea surface.

[0018] Preferably, the floating structure further comprises an offshore wave suppression means that is located offshore with respect to the rotation axis of the floating structure and that suppresses waves from the offshore side from directly hitting the wave receiving blades located above the rotation axis.

[0019] Preferably, the vessel further comprises a shore-side wave suppression means for suppressing waves from directly hitting the wave receiving blades located at or below the height of the rotation shaft.

[0020] Preferably, the wave receiving blades are shaped to provide greater resistance to waves coming from the offshore side and less resistance to waves coming from the shore side.

[0021] Preferably, the wave inflow channel has a width in a direction substantially perpendicular to the direction in which the waves flow in that is shorter on the shore side than on the offshore side.

[0022] Preferably, a generator for extracting rotational energy is attached to the rotating shaft, and a flywheel having rotational inertia is attached to the same rotating shaft.

[0023] Preferably, the function of controlling the rotational torque of the generator is characterized by extracting electric power as a generator for a specific rotation direction of the generator, and adding rotational energy as a motor for a rotation direction opposite to the specific rotation direction, and the amount of power generated is the difference between the electric power extracted as the generator and the energy loaded as rotational energy.

[0024] The present invention comprises a first step of using a water level gauge to identify an installation position on the sea where the mean water level is shallower than half the mean wavelength of the waves; a second step of fixing one end of a mooring part to the seabed and attaching the other end of the mooring part to a floating body, and floatingly positioning the floating-type wave power generation device at the installation position; and a third step of generating power with the floating-type wave power generation device installed at the installation position in the second step. The floating-type wave power generation device comprises the floating body provided with a wave inlet, and a plurality of wave receiving blades that rotate 360 ​​degrees around a predetermined rotation axis fixed to the floating body, a rotating body that receives waves flowing in from the wave inlet channel with the plurality of wave receiving blades and rotates, a generator attached to the rotation axis, and mooring members that moor the floating body to the seabed in a state where it can float on the sea surface, and the wave receiving blades are rotated by the waves flowing in from the wave inlet channel, and power is generated by the generator based on the rotational force of the rotation axis corresponding to the rotation. Effect of the Invention

[0025] According to the present invention, it is possible to provide a floating wave power generation device and a power generation method that can be easily installed on the sea and can obtain high power generation efficiency. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a diagram for explaining the configuration of the planar side of a floating wave power generation device 1 according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram for explaining the configuration of the side surface of the floating type wave power generation device 1 shown in FIG. [Diagram 3] FIG. 3 is a diagram for explaining a modified example of the floating type wave power generation device 1 shown in FIG. [Figure 4] FIG. 4 is a flow chart for explaining a power generation method using the floating type wave power generation device 1 shown in FIG. [Diagram 5] FIG. 5 is a diagram for explaining the configuration of the side surface of the floating type wave power generation device 1 according to the second embodiment of the present invention. [Figure 6] FIG. 6 is a diagram for explaining the configuration of the side surface of the floating type wave power generation device 1 according to the third embodiment of the present invention. [Figure 7] FIG. 7 is a diagram for explaining the configuration of the planar side of the floating type wave power generation device 1 according to the fourth embodiment of the present invention. [Figure 8] FIG. 8 is a diagram for explaining the configuration of the side surface of the floating type wave power generation device 1 according to the fifth embodiment of the present invention. [Figure 9] FIG. 9 is a diagram for explaining the configuration of the planar side of the floating type wave power generation device 1 according to the sixth embodiment of the present invention. [Figure 10] FIG. 10 is a diagram for explaining the first conventional technique. [Figure 11] FIG. 11 is a diagram for explaining the second conventional technique. [Figure 12] FIG. 12 is a diagram for explaining the third conventional technique. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, a floating wave power generation device according to an embodiment of the present invention will be described. The present invention provides an efficient power generation facility at a coastal location (a location away from the coast or breakwater where the water depth is shorter than the wavelength of the waves) where a group velocity component occurs in response to the periodic vibration component of the waves.

[0028] First Embodiment FIG. 1 is a diagram for explaining the configuration of the planar side of a floating wave power generation device 1 according to a first embodiment of the present invention. FIG. 2 is a diagram for explaining the configuration of the side surface of the floating type wave power generation device 1 shown in FIG.

[0029] As shown in Figs. 1 and 2, a floating wave power generation device 1 is a wave power generation device that floats on the sea surface. The floating wave power generation device 1 includes, for example, a floating body 3, a rotating body 5, a generator 7, and a mooring part 9. The floating body 3 is provided with a wave inlet 11 through which waves from the offshore flow in.

[0030] The rotor 5 directs the waves flowing in from the wave inlet 11 to the multiple wave receiving blades 17. A plurality of wave receiving blades 17 that rotate 360 ​​degrees around a rotation shaft 15 fixed to the floating body 3 are positioned in the wave inflow channel 11. The rotation shaft 15 is fixed to the floating body 3 via a rotation holder (bearing). The generator 7 is attached to a rotating shaft 15 and generates electricity using the rotation of the rotating shaft 15.

[0031] The mooring unit 9 moors the floating body 3 to the seabed (ocean bottom surface) 19. The mooring unit 9 fixes the floating body 3 so that the floating body 3 is located at an installation position where the average water level is shallower than half the average wavelength of the waves. The mooring unit 9 is, for example, a rope. The mooring unit 9 moors the floating body 3 to the seabed 19 by, for example, fixing four ropes to the four corners of the bottom surface of the floating body 3.

[0032] The mooring section 9 moor the floating body 3 so that the average group velocity of waves at the installation position of the floating body 3 is greater than ⅛ of the wavelength at the installation position.

[0033] The mooring section 9 moors the floating body 3 so that the rotation axis 15 is positioned above the average draft surface of the floating body 3 at the installation position and the longitudinal direction of the rotation axis 15 is approximately perpendicular to the average direction of travel of waves on the sea surface at the installation position.

[0034] In the floating wave power generation device 1, the water level of the floating body 3 is the average water level of the sea surface, so when the waves become rough and the wave height increases, if the wave height is higher than the water level of the floating body 3 above the rotation axis 15 and the floating body 3 above the sea is exposed, when the overtopping waves reach above the rotation axis 15, this acts as a rotational force in the opposite direction to the lower side of the rotation axis 15, thereby acting in the direction of reducing the rotational energy.

[0035] As shown in FIG. 2, a waterline 31 is defined. Since the rotation axis 15 is located higher than the water surface 31 of the floating body 3, and the water surface 31 corresponds to the mean water level of the sea surface, the wave forces acting below the rotation axis 15 on the four or more wave receiving blades 17 installed on the floating body 3 are greater than the wave forces acting above the rotation axis 15, and in Figure 1, the force rotating counterclockwise becomes more dominant than the force rotating clockwise.

[0036] By installing the rotor 5 on the floating body 3 moored to the seabed 33, the distance between the seabed 33 and the wave receiving blade 17 can be kept constant. By ensuring that the length of the wave receiving blade 17 is as close as possible to the seabed 33, energy can be extracted from a wide range up to the seabed 33. In order to prevent the wave receiving blade 17 from coming into contact with the seabed 33 and being damaged by the up and down movement of the floating body 3 caused by waves, changes in sea level caused by tides and sea level rise, etc., it is necessary to provide a certain amount of clearance between the floating body 3 and the seabed 33. This has the disadvantage that the surface area receiving waves is smaller than when it is fixed on the sea, but since the draft position of the floating body 3 is always at the average wave height position, it is possible to install a constant wave receiving blade 17 at a depth where wave energy is concentrated. On the other hand, in the case of an offshore structure fixed to the seabed 33, it is necessary to respond to up and down movement caused by waves and changes in sea level caused by tides and sea level rise with a fixed length wave receiving blade 17, and it is necessary to contact a wave receiving blade 17 that is larger than necessary.

[0037] When a floating body is fixed to the seabed 33, the length of the wave receiving blades becomes very long, and therefore the floating body needs to oscillate in accordance with the wave period relative to the installation position. Therefore, it is necessary to extract the oscillating energy during one round trip in a typical wave period of about 8 to 12 seconds. In the case of the wave receiving plate 13 having a mechanism for rotating 360° as in this embodiment, the tip of the wave receiving plate 13 can move at about the group velocity of the waves, so "rotation angle of the wave receiving plate 13 (° / s) = 360° × (length of the wave receiving plate × 2 × π) / group velocity component of the waves (m / s)". When the rotation angle of the wave receiving plate 13 is 360°, if four wave receiving plates 13 are installed on the rotation shaft 15, four times as many effective wave receiving plates 13 come into contact with the sea surface, and if eight plates are installed, eight times as many effective wave receiving plates 13 come into contact with the sea surface, so the equivalent wave receiving area can be expanded. An example of the case where eight plates are installed is shown in FIG. 3. Of the eight wave receiving plates 17 installed on the rotation shaft 15, wave forces Xa and Xb are applied to the wave receiving vanes 17a and 17b, respectively. Although the length of the wave receiving blade 17 is limited, the equivalent wave receiving area can be increased by configuring it with multiple wave receiving blades 17 that can rotate 360 ​​degrees, which makes it possible to ensure the amount of power generation while maintaining a strong offshore structure for use on rough seas and reducing installation costs as a result.

[0038] The floating type wave power generation device 1 extracts energy for 8 seconds with a wave size of 8 to 12 seconds, a wave length of 40 to 60 m, etc. In this embodiment, the multiple wave receiving blades 17 receive waves, so that wave energy can be efficiently extracted. In order to extract the energy of waves, the wave receiving blades 17 receive the waves and transmit the force to the generator 7 to extract the energy. In order to extract the energy, it is necessary to operate the reflector in accordance with the waves over as wide a range as possible. In the horizontal direction, this is the swing angle or the horizontal movement amount. When using a swinging reflector with a limited movable range with respect to the rotation axis 15, ideally, it is necessary to evenly touch the direction from which the waves come (offshore side) and the direction from which the waves leave (shore side) with the vertical direction of the waves as the center. However, since the group velocity component of the waves is included in addition to the vibration component of the waves from the offshore side to the shore side, the wave receiving plate 17 is inclined toward the shore side. As a result, the swing range of the wave receiving plate 17 becomes narrower, and the wave energy received by the wave receiving plate 17 decreases, and the amount of power generation decreases.

[0039] Since the rotation axis 15 of the floating wave power generation device 1 rotates 360 degrees, even if a group velocity component from the offshore is added to the waves and causes the wave receiving plate 17 to rotate, the weight is balanced because the wave receiving plate 17 is point-symmetric with respect to the rotation axis 15, and energy that hits the wave receiving plate can be extracted as energy without depending on the phase of the rotation angle of the wave receiving blades. In addition, since wave energy can be extracted regardless of the wave phase, there is no need to install a caisson wall or other reflective structure located 1 / 4 wavelength away from the wave receiving plate 17 to align the wave phase components using the resonance phenomenon, making it possible to install power generation equipment on a floating structure.

[0040] The waves that exist on the sea are irregular and generally have a Rayleigh distribution. At the same time, because many wave components overlap, the wave phase is random. In other words, the wave peak following one wave peak is not necessarily one wave period later (360° in phase). If a design is made using the average period of the waves in the horizontal or vertical direction, and the next wave arrives randomly relative to the previous wave, a jump in phase will occur, and at that timing the direction and phase of the energy will change suddenly, acting as a brake, causing a loss in the energy that can be extracted, and reducing the amount of energy that can be extracted.

[0041] In the floating wave power generation device 1, four or more wave receiving plates 17 are arranged at equal intervals on the rotation axis 15. Therefore, even if a wave arrives randomly in relation to the previous wave, the next wave receiving plate 17 exists within a phase range of 90° in the case of four plates, and 45° in the case of eight plates, so the phase shift between one wave can be absorbed. When the group velocity of the waves is 1 / 8 or more of the wavelength of the waves, the group velocity component rotates the rotation axis 15 by 1 / 8 or more during one wave period, and when there are four wave receiving plates, two of the wave receiving plates come into contact with the wave front, making it possible to capture more wave energy than with one plate. The larger the group velocity component of the waves, the more wave receiving plates come into contact with the wave front within one wave period, making it possible to capture energy.

[0042] A power generation method using the floating wave power generation device 1 will be described below. FIG. 4 is a flow chart for explaining a power generation method using the floating type wave power generation device 1 shown in FIG. Each step will be explained. Step ST1: In coastal areas, the sea water level is measured using a water level gauge to identify installation locations where the average water level is shallower than half the average wavelength of the waves and the average group velocity of the waves is greater than 1 / 8 of the wavelength of the waves.

[0043] STEP ST2: As shown in Figure 2, one end of the mooring part 9 of the floating wave power generation device 1 is fixed to the seabed 19, the other end of the mooring part 9 is attached to the floating body 3, and the floating wave power generation device 1 is positioned at the installation position on the sea identified in step ST1. At this time, as shown in FIG. 1, the floating type wave power generation device 1 is positioned so that the wave inlet 11 of the floating body 3 faces the offshore direction.

[0044] Step ST3: Waves from the ocean flow into the wave inflow channel 11 of the floating body 3 and hit the wave receiving blades 17, causing the wave receiving blades 17 to rotate around the rotating shaft 15. Then, the generator 7 converts the rotational force of the rotating shaft 15 into electrical energy to generate electricity.

[0045] As described above, according to the floating wave power generation device 1, in coastal waters where there is a wide possibility of installing wave power generation devices, when the waves have a group velocity component in addition to a periodic component due to the influence of the seabed, it becomes possible to extract energy including the energy of the group velocity component.

[0046] <Second embodiment> FIG. 5 is a diagram for explaining the configuration of the side surface of the floating type wave power generation device 1 according to the second embodiment of the present invention. In FIG. 5, components denoted by the same reference numerals as those in FIG. 2 are the same as those described in the first embodiment. As shown in FIG. 5, the floating type wave power generation device 1 of this embodiment has an offshore wave suppression section 41. The offshore wave suppression part 41 is, for example, a plate-like member, and is fixed to or formed integrally with the floating body 3. For example, the offshore wave suppression part 41 is wider than the width of the wave receiving blade 17 in the width direction and higher than the rotational circumference of the wave receiving blade 17 in the height direction.

[0047] The offshore wave suppression unit 41 is located on the offshore side of the rotation axis 15 of the floating body 3, and suppresses waves from the offshore side from directly hitting the wave receiving blade 17 located above the rotation axis 15. This makes it possible to weaken the rotational force that rotates the wave receiving blade 17 clockwise. In this embodiment, by providing the offshore wave suppression unit 41, the clockwise rotation efficiency of the rotor 5 can be increased, and the power generation efficiency can be increased.

[0048] <Third embodiment> FIG. 6 is a diagram for explaining the configuration of the side surface of the floating type wave power generation device 1 according to the third embodiment of the present invention. In FIG. 6, components denoted by the same reference numerals as those in FIG. 2 are the same as those described in the first embodiment. As shown in FIG. 6, the floating type wave power generation device 1 of this embodiment has a shore side wave suppression section 45. The shore side wave suppressor 45 is fixed to the floating body 3 or formed integrally with the floating body 3 . By installing the shore side wave suppression section 45, waves on the shore side, including at positions below the waterline, are prevented from directly hitting the wave receiving blade 17. When the horizontal force F1 of the waves from offshore is equal to the horizontal force F2 of the waves from shore, the horizontal force of the waves from shore is reduced as they hit the floating body 3, becoming a force F3 which is smaller than F2. Taking into account the group velocity component, the force applied to the wave receiving plate from offshore is F1 + F4, but the force applied to the wave receiving plate from shore is F3 - F4. When F4 is larger than F3, F3 - F4 becomes negative, and the direction of rotation of the wave receiving plate 17 becomes a constant direction rather than a reciprocating motion.

[0049] <Fourth embodiment> FIG. 7 is a diagram for explaining the configuration of the planar side of the floating type wave power generation device 1 according to the fourth embodiment of the present invention. In FIG. 7, components denoted by the same reference numerals as those in FIG. 2 are the same as those described in the first embodiment. As shown in FIG. 7, in the floating type wave power generation device 1 of this embodiment, the shape of a floating body 103 is different from that of the floating body 3 of the first embodiment. As shown in Fig. 7, the wave inlet channel 11 of the floating body 103 has a width L2 on the offshore side, which is the wave arrival direction, wider than a width L1 on the shore side. As a result, the width of the wave inlet channel 11 narrows from the offshore side toward the wave receiving blade 17, and a larger amount of seawater can be guided to the wave receiving blade 17 compared to the floating body 3 of the first embodiment, and the force of the group velocity component can be accelerated and acted on the wave receiving blade 17.

[0050] The floating wave power generation device 1 provides a width for the cutting teeth in the direction parallel to the waves by installing a bearing and a generator 7 on the rotating shaft 15 of the floating body 3. By widening the opening surface of the floating body 3, the force acting on the wave receiving plate 17 can be maintained even if a generator, etc. is installed.

[0051] <Fifth embodiment> FIG. 8 is a diagram for explaining the configuration of the side surface of the floating type wave power generation device 1 according to the fifth embodiment of the present invention. In FIG. 8, components denoted by the same reference numerals as those in FIG. 2 are the same as those described in the first embodiment. As shown in FIG. 8, in the floating type wave power generation device 1 of this embodiment, the shape of the wave receiving vane 117 is different from that of the wave receiving vane 17 of the first embodiment.

[0052] By changing the angle of the surface of the wave receiving blade 117 that the waves hit, relative to the offshore direction, which is the direction in which the traveling waves arrive, the wave resistance is increased in the direction in which the traveling waves arrive (offshore) and is reduced in the direction opposite to the direction in which the traveling waves arrive (shore). As shown in Figure 8, the tip of the wave receiving blade 117 is bent from offshore towards the side that receives the waves. As a result, when the same rocking wave occurs, there is a difference between the force F1 from the offshore side and the force F2 from the shore side, with F1 > F2. When the forces of the traveling waves are combined, the counterclockwise rotation becomes larger than the clockwise rotation.

[0053] Sixth Embodiment FIG. 9 is a diagram for explaining the configuration of the planar side of the floating type wave power generation device 1 according to the sixth embodiment of the present invention. In FIG. 9, components denoted by the same reference numerals as those in FIG. 1 are the same as those described in the first embodiment. As shown in Fig. 9, in the floating wave power generator 1 of this embodiment, by attaching a flywheel 65 with a large rotational moment in the other direction of the rotating shaft 15, part of the energy generated by waves can be retained as rotational energy of the flywheel 65. Alternatively, when a speed-up gear is installed between the rotating shaft 15 and the generator 7, it is also possible to attach the flywheel 65 between the speed-up gear and the generator. If the clockwise force generated from the shore side is smaller than the counterclockwise force in Fig. 8 stored in the flywheel 65, the wave receiving plate 17 will continue to rotate counterclockwise relative to the rotating shaft 15.

[0054] Seventh embodiment By controlling the inverter connected to the generator 7, when the clockwise rotation of the wave receiving plate 17 on the rotating shaft 15 caused by waves from the shore side as shown in FIG. 6 is sufficiently small relative to the counterclockwise rotation of the wave receiving plate on the rotating shaft caused by waves from the offshore side as shown in FIG. 8, the inverter controls so that the generator generates electricity when the rotation is counterclockwise, and when a clockwise force is applied, an equivalent counterclockwise force is applied to the generator 7 to operate as a motor. As a result, the rotating shaft 15 always rotates in a fixed direction, reducing losses due to the rolling resistance caused by the bearing starting to slip due to the rotation stopping temporarily during the timing when the rotation direction is always switched, and at the same time, suppressing losses in the low power generation efficiency area of ​​the generator 7 at low speeds, and controlling so that the energy generated and the energy required for control as a motor are minimized, thereby enabling efficient power generation by always rotating in a fixed direction on the rotating shaft 15.

[0055] The present invention is not limited to the above-described embodiments. In other words, those skilled in the art may make various modifications, combinations, sub-combinations, and substitutions of the components of the above-described embodiment within the technical scope of the present invention or an equivalent scope. [Industrial Applicability]

[0056] The present invention is applicable to floating wave power generation devices. [Explanation of symbols]

[0057] 1. Floating wave power generation device 3...Floating object 5...Rotating body 7. Generator 9…Mooring section 11...Wave inlet channel 15...Rotation axis 17…Namiukeba 19…Undersea

Claims

1. A wave power generation device floating on the sea surface at a coastal location, A floating body having a wave inlet; A rotating body includes a plurality of wave receiving blades that rotate 360 ​​degrees around a predetermined rotation axis fixed to the floating body, and rotates by receiving waves flowing in from the wave inflow channel with the plurality of wave receiving blades; A generator attached to the rotating shaft; A mooring member that moors the floating body to the seabed in a state in which the floating body can float on the sea surface; a flywheel having a rotational inertia force attached to the same rotation shaft as the generator for extracting rotational energy attached to the rotation shaft; having The function of controlling the rotational torque of the generator is characterized by extracting electric power as the generator in a specific rotation direction of the generator, and adding rotational energy as a motor in the direction opposite to the specific rotation direction, and the amount of power generated is the difference between the electric power extracted as the generator and the energy loaded as rotational energy. Floating wave power generation device.

2. The mooring member moors the floating body so that the floating body is located at a setting position at a mean water level shallower than half the mean wavelength of the waves. The floating wave power generation device according to claim 1.

3. The mooring member moors the floating body so that the floating body is located at the installation position where the average group velocity of the waves is greater than 1 / 8 of the wavelength of the waves. The floating wave power generation device according to claim 2.

4. The anchoring member is The floating body is moored so that the rotation axis is located above the average water surface of the floating body and the longitudinal direction of the rotation axis is approximately perpendicular to the average traveling direction of waves on the sea surface. The floating wave power generation device according to claim 3.

5. an offshore wave suppression means for suppressing waves from directly hitting the wave receiving blades located above the rotation shaft and located offshore with respect to the rotation shaft of the floating body; The floating wave power generation device according to claim 4, further comprising:

6. A shore-side wave suppression means for suppressing waves from directly hitting the wave receiving blades located at the height of the rotation shaft or below the height of the rotation shaft. The floating wave power generation device according to claim 4, further comprising:

7. The wave receiving blades are shaped to provide greater resistance to waves coming from the offshore side and less resistance to waves coming from the shore side. The floating wave power generation device according to claim 4.

8. The wave inflow channel has a width in a direction substantially perpendicular to the direction in which the waves flow in that is shorter on the shore side than on the offshore side. The floating wave power generation device according to claim 4.

9. A first step of identifying an installation position on the sea surface where the mean water level is shallower than half the mean wavelength of the waves using a water level gauge; a second step of fixing one end of the mooring part to the seabed and attaching the other end of the mooring part to a floating body to float and position the floating wave power generation device at the installation position; a third step of generating power by the floating wave power generation device installed at the installation position in the second step; having The floating type wave power generation device includes: The floating body is provided with a wave inflow passage; A rotating body includes a plurality of wave receiving blades that rotate 360 ​​degrees around a predetermined rotation axis fixed to the floating body, and rotates by receiving waves flowing in from the wave inflow channel with the plurality of wave receiving blades; A generator attached to the rotating shaft; A mooring member that moors the floating body to the seabed in a state in which the floating body can float on the sea surface; a flywheel having a rotational inertia force attached to the same rotation shaft as the generator for extracting rotational energy attached to the rotation shaft; having The wave receiving blade is rotated by the waves flowing in from the wave inlet, and electricity is generated by the generator based on the rotational force of the rotating shaft corresponding to the rotation. The function of controlling the rotational torque of the generator is characterized by extracting electric power as the generator in a specific rotation direction of the generator, and adding rotational energy as a motor in the direction opposite to the specific rotation direction, and the amount of power generated is the difference between the electric power extracted as the generator and the energy loaded as rotational energy. Power generation method.

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