Floating wave power generation device and power generation method

Abstract

To provide a floating type wave power generation device capable of being easily installed on the sea and obtaining high power generation efficiency.SOLUTION: A floating type wave power generation device floating on a sea surface includes a floating body including a wave inflow path, a rotating body including a plurality of wave receiving blades that rotate 360 degrees around a predetermined rotating shaft fixed to the floating body, the rotating body receiving waves flowing in from the wave inflow path with the plurality of wave receiving blades and rotating, a power generator attached to the rotating shaft, and a mooring member that moors the floating body on a sea bottom in a state where the floating body can float on the sea surface.SELECTED DRAWING: Figure 2

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 received by a wave receiving plate attached to a rotating shaft, and to a power generation method thereof. [Background technology]

[0002] Ocean energy, a type of natural energy, originates from thermal energy from the sun, and its interactions include the movement of air caused by the distribution of thermal energy in the atmosphere, and the movement of seawater caused by thermal energy in the ocean. 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 oscillating water column type, movable object type, and wave overtopping type.

[0003] An example of the configuration of an oscillating water column type is shown in Figure 10. A floating object 113 is attached to a column 111 that is fixedly or moored to the seabed 19. The floating object 111 is structured so that it can move in accordance with changes in the sea level. The floating object 113 absorbs the up and down movement of the sea surface caused by waves that occur on the sea surface, and the fluctuations in its position relative to the column 111 are 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 is installed on a breakwater 121, offshore structure 123, or the like on the seabed 19. 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 this vibration into energy to generate electricity.

[0005] An example of the configuration of a 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 is provided between the wave overtopping plate 133 and the breakwater to store seawater from overtopping waves. A water channel 137 is provided midway between the wave overtopping water storage space 135 and the wave overtopping plate. The overtopping plate 133 and the seawater that has overtopped the waves collect in the wave overtopping water storage space 135. When the water level on the sea surface side of the wave overtopping pillar 133 drops below the water level stored in the wave overtopping storage space 135, the plate 133 is released. At that time, the potential energy of the water flow installed in the water channel 137 is converted into kinetic energy, and this energy is used to generate electricity. In addition, in areas where there are constant water currents (tidal currents, ocean currents) in the seawater, there are structures in which a propeller-shaped 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] Japanese Patent Application Publication No. 2024-20118 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 by the fact that the wave power generation device comprises a rotating shaft installed on the floating structure, the wave receiving plate attached to which can rotate 360 ​​degrees around the rotating shaft, four or more wave receiving plates of the same length arranged radially from the rotating shaft, and a generator that extracts rotational energy attached to the rotating shaft, which extracts the energy of the seawater waves received by the wave receiving plate as rotational energy of the 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 tidal currents, which have a certain direction, and wave energy, which is the vertical and horizontal kinetic energy of the water surface rotating with a certain period. When there are no ocean currents or tidal currents and the water is deep enough, the vertical and horizontal kinetic energy are the same. In addition, where waves come into contact with the coast, the horizontal energy of the waves is reflected by breakwaters, etc., so methods are used to convert the vertical kinetic energy of the waves into electrical energy.

[0009] Because ocean currents and tides are dominant far from the coast, power generation is often performed using a rotating body installed on the ocean floor in deep water, which results in extremely large facilities. In ocean areas far from the coast, there is a method of generating power by using a power generating body that can deform to match the wave wavelength (several meters) or more to match the wave swell, but in this case too, the size of the power generating body must be approximately the wavelength of the waves, which makes it extremely large. On the other hand, because waves tend to be higher near land, such as on the coast or breakwaters, power generation is often achieved by the movement of oscillating water columns or movable objects installed on the coast, breakwaters, or in locations close to them. Installation on the coast or breakwater has the advantage of reducing the initial cost of installation, since the location for installing the power generation equipment already exists, eliminating the need to build new structures. However, coasts and breakwaters are already in use, and in locations where wave energy is high and suitable for wave power generation, wave-dissipating blocks and other structures are generally installed to prevent erosion by waves, limiting the number of locations where power generation equipment can be installed adjacent to the coast or breakwater. In wave power generation, wave energy is absorbed and converted into electrical energy, so it is thought that it could be used as a substitute for wave-dissipating blocks, 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 installed close to the coast or a breakwater.

[0010] Given these factors, it is expected that the freedom to install wave power generation devices will expand if there is a wave power generation system that can be installed in coastal areas a little distance from the shore or breakwaters. When installing a facility in a coastal area some distance from the shore or breakwater, there are three major challenges.

[0011] First, the power generation equipment needs to be installed in a location with a certain degree of water depth. However, locations suitable for wave power generation have relatively large waves, 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 it needs to have a structurally strong design, and the construction work to secure it to the seabed is extensive.

[0012] Second, when wave energy is transmitted from deep water to the coast or breakwater, the waves are formed by a periodic rotation of vertical and horizontal energy. As this wave energy propagates toward the coast or the coastal portion of a breakwater, the effects of the seabed begin to appear when the water reaches a depth equivalent to the wavelength of the wave. As the water depth decreases, the cross-sectional area of ​​the wave in the direction of travel gradually decreases, and some of the periodic rotation of the wave energy is converted into group velocity energy, which has a velocity component in the direction of travel. The group velocity component of the wave changes the wave periodicity. Because the wave periodicity is disrupted, power generation methods that utilize vertical and horizontal periodicity decrease in efficiency. To suppress the group velocity component and maintain wave periodicity, methods are being considered for creating ideal conditions by using caissons or fixed structures on three or one side of the power generation facility, thereby canceling the non-periodic components of the waves through resonance at the location where the power generation facility receives wave energy. In this case, an ideal situation can be created if the designed specific wavelength has a constant period over the long term, but in order to create an ideal wave situation by canceling out the incident energy and reflected energy in terms of the group velocity component of the wave, energy that contributes 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 waves with random amplitude and phase. When the waves are calm and low in height, 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 subsequent 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 synchronization and resonance, and reducing power generation efficiency.

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

[0015] The present invention is a 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 that flow in from the wave inlet with the plurality of wave receiving blades, 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. Preferably, the mooring members moor the floating body so that the floating body is located at a set position where the mean water level is 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 rotation axis is located above the mean draft plane of the floating body and the longitudinal direction of the rotation axis is approximately perpendicular to the mean direction of wave movement on the sea surface.

[0018] Preferably, the floating body further comprises an offshore wave suppression means that is located offshore with respect to the rotation axis of the floating body and that prevents waves 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 the shore side 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 width of the wave inflow channel in a direction substantially perpendicular to the direction in which the waves flow in is shorter on the shore side than on the offshore side.

[0022] Preferably, a flywheel having rotational inertia force is attached to the same rotating shaft as the generator that is attached to the rotating shaft and extracts rotational energy.

[0023] Preferably, 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 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 positioning the floating wave power generation device in a floating manner at the installation position; and a third step of generating power using the floating wave power generation device installed at the installation position in the second step.The floating wave power generation device comprises the floating body provided with a wave inlet channel, 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 that have flowed 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 that have flowed 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. [Effects 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 achieve high power generation efficiency. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a diagram illustrating the configuration of the planar side of a floating wave power generation device 1 according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram for explaining the configuration of the side surface of the floating wave power generator 1 shown in FIG. [Figure 3] FIG. 3 is a diagram for explaining a modified example of the floating wave power generator 1 shown in FIG. [Figure 4] FIG. 4 is a flowchart illustrating a power generation method using the floating wave power generation device 1 shown in FIG. [Figure 5] FIG. 5 is a diagram illustrating the configuration of the side surface of the floating wave power generator 1 according to the second embodiment of the present invention. [Figure 6] FIG. 6 is a diagram illustrating the configuration of the side surface of the floating 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 wave power generation device 1 according to the fourth embodiment of the present invention. [Figure 8] FIG. 8 is a diagram illustrating the configuration of the side surface of the floating wave power generator 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 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 INVENTION

[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 coastal locations (locations away from the coast or breakwaters where the water depth is shorter than the wavelength of the waves) where group velocity components occur in response to the periodic vibration components of the waves.

[0028] First Embodiment FIG. 1 is a diagram illustrating 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 wave power generator 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 inflow channel 11 through which waves from offshore flow in.

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

[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 positioned 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, they act as a rotational force in the opposite direction to the below on the rotation axis 15, thereby working 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 draft surface 31 of the floating body 3, and the draft surface 31 corresponds to the average 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 to the seabed 33 as possible, energy can be extracted from a wide range up to the seabed 33. In order to prevent the wave-receiving vanes 17 from coming into contact with and being damaged by the up and down movement of the floating body 3 due to waves, changes in sea level due to 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 that receives waves is smaller than when the floating body 3 is fixed on the sea, but because the draft position of the floating body 3 is always at the position of the average wave height of the waves, it is possible to always install a constant wave-receiving vane 17 at the 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 deal with up and down movement due to waves and changes in sea level due to tides and sea level rise with a wave-receiving vane 17 of a fixed length, and therefore it is necessary to use a wave-receiving vane 17 that is larger than necessary.

[0037] When a floating body is installed fixed to the seabed 33, the length of the wave receiving blades becomes very long, so the floating body needs to oscillate in accordance with the wave period relative to the installation position, and 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 a wave receiving plate 13 with a mechanism that rotates 360°, as in this embodiment, the tip of the wave receiving plate 13 can move at approximately the group velocity of the waves, so the 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 around the rotation axis 15, four times as many effective wave receiving plates 13 come into contact with the sea surface. If eight wave receiving plates 13 are installed, eight times as many effective wave receiving plates 13 come into contact with the sea surface. This allows for an increase in the equivalent wave receiving area. Figure 3 shows an example when eight plates are installed. Of the eight wave receiving plates 17 installed around the rotation axis 15, wave forces Xa and Xb are applied to the wave receiving vanes 17a and 17b, respectively. Although the length of the wave receiving blades 17 is limited, by configuring the structure with multiple wave receiving blades 17 that can rotate 360 ​​degrees, the equivalent wave receiving area can be increased, making it possible to ensure the amount of power generation while building a strong offshore structure for use on rough seas and reducing installation costs as a result.

[0038] The floating wave power generator 1 extracts energy for 8 seconds when the wave size is 8 to 12 seconds, the wave length is 40 to 60 m, and the wave energy is extracted. In this embodiment, the multiple wave receiving blades 17 receive the waves, so that the wave energy can be extracted efficiently. To extract wave energy, the wave receiving blades 17 receive the waves and transmit the force to the generator 7, thereby extracting energy. To extract 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 horizontal movement. When using a swinging reflector with a limited range of movement relative to the rotation axis 15, ideally, it is necessary for the reflector to be evenly in contact with the direction from which the waves are coming (offshore) and the direction from which the waves are leaving (shore), centered on the vertical direction of the waves. However, since the wave receiving blade 17 includes not only the vibration component of the waves moving from offshore to shore, but also the group velocity component of the waves, it tilts the reflector toward shore. This narrows the swing range of the reflector 17, reducing the wave energy received by the reflector 17 and the amount of power generated.

[0039] In the floating wave power generation device 1, the rotation axis 15 rotates 360°, so even if a group velocity component from the offshore side is added to the waves and the wave receiving plate 17 rotates, the weight is balanced because the wave receiving plate 17 is point-symmetric with respect to the rotation axis 15, and energy can be extracted from the wave receiving plate without depending on the phase of the rotation angle of the wave receiving blades. Furthermore, since wave energy can be extracted regardless of the wave phase, it is not necessary to install a caisson wall or a 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] Waves that exist on the ocean are irregular and generally follow 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 does not necessarily occur one wave period later (360° in phase). When designing using an average period for the horizontal or vertical waves, if the next wave arrives randomly relative to the previous wave, a jump in phase will occur. At that time, the direction and phase of the energy will change suddenly, acting as a brake, resulting in a loss of 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, so even if a wave arrives randomly relative to the previous wave, the next wave receiving plate 17 will be present 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 waves 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 causes the rotation axis 15 to rotate 1 / 8 or more times during one wave cycle, and when there are four wave receiving plates, two of the plates come into contact with the wave front, allowing more wave energy to be captured 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 cycle, 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 flowchart illustrating a power generation method using the floating wave power generation device 1 shown in FIG. Each step will be explained. Step ST1: In coastal areas, the sea level is measured using a water level gauge, and the installation location is identified 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 wave power generation device 1 is positioned so that the wave inlet channel 11 of the floating body 3 faces offshore.

[0044] Step ST3: Waves from offshore 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 rotation shaft 15. Then, the generator 7 converts the rotational force of the rotation shaft 15 into electrical energy to generate electricity.

[0045] As described above, the floating wave power generation device 1 makes it possible to extract energy including the energy of the group velocity component 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 the periodic component due to the influence of the seabed.

[0046] Second Embodiment FIG. 5 is a diagram illustrating the configuration of the side surface of the floating wave power generator 1 according to the second embodiment of the present invention. In FIG. 5, the 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 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 offshore with respect to 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 suppressor 41, the clockwise rotation efficiency of the rotor 5 can be increased, and power generation efficiency can be increased.

[0048] Third Embodiment FIG. 6 is a diagram illustrating the configuration of the side surface of the floating wave power generation device 1 according to the third embodiment of the present invention. In FIG. 6, the 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 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 part 45, waves on the shore side, including at positions below the waterline, are prevented from directly hitting the wave receiving blades 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 wave power generation device 1 according to the fourth embodiment of the present invention. In FIG. 7, the 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 wave power generation device 1 of this embodiment, the shape of the 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 direction in which the waves arrive, that is wider than the 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, among the group velocity components of waves coming from the offshore side, 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 generator 1 provides a width for the cutting edge in the direction parallel to the waves by installing a bearing and a generator 7 on the rotation axis 15 of the floating body 3. By widening the opening of the floating body 3, the force acting on the wave receiving plate 17 can be maintained even when a generator, etc. is installed.

[0051] Fifth Embodiment FIG. 8 is a diagram illustrating the configuration of the side surface of the floating wave power generator 1 according to the fifth embodiment of the present invention. In FIG. 8, the 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 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 progressive waves arrive, the wave resistance in the direction in which the progressive waves arrive (offshore) is increased, and the wave resistance in the opposite direction in which the progressive waves arrive (shore) is decreased. 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 wave power generation device 1 according to the sixth embodiment of the present invention. In FIG. 9, the 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 Figure 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, if a speed increaser is installed between the rotating shaft 15 and the generator 7, the flywheel 65 can also be attached between the speed increaser and the generator. If the clockwise force generated from the shore side is smaller than the counterclockwise force in Figure 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 generator 7, if the clockwise rotation of wave receiving plate 17 on rotating shaft 15 caused by waves from the shore (as shown in Figure 6) is sufficiently small compared to the counterclockwise rotation of the wave receiving plate on the rotating shaft caused by waves from offshore (as shown in Figure 8), the inverter controls so that the generator generates electricity when the rotation is counterclockwise, and when a clockwise force is applied, an equal counterclockwise force is applied to generator 7, causing it to function as a motor. In this way, rotating shaft 15 always rotates in a fixed direction, reducing losses due to bearing slippage and rolling resistance caused by the rotation stopping temporarily when the direction of rotation changes, and at the same time suppressing losses in the low power generation efficiency range of generator 7 at low speeds. By controlling so that the energy generated and the energy required to control it as a motor are minimized, efficient power generation is achieved by constantly rotating in a fixed direction on rotating shaft 15.

[0055] The present invention is not limited to the above-described embodiments. That is, those skilled in the art may make various modifications, combinations, subcombinations, and substitutions of the components of the above-described embodiments within the technical scope of the present invention or its equivalents. [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 body 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, a floating body having a wave inlet; a rotating body that includes 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 that have flowed in from the wave inlet channel with the plurality of wave receiving blades; a generator attached to the rotating shaft; a mooring member for mooring the floating body to the seabed in a state in which the floating body can float on the sea surface; A floating wave power generation device having the above structure.

2. The mooring members moor 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 waves. The floating wave power generation device according to claim 1.

3. The mooring members moor 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 mean draft of the floating body and the longitudinal direction of the rotation axis is approximately perpendicular to the mean direction of travel of waves on the sea surface. The floating wave power generation device according to claim 3.

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

6. 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 offshore and less resistance to waves coming from shore. 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 generator that extracts rotational energy is attached to the rotating shaft, and a flywheel with rotational inertia is attached to the same rotating shaft. The floating wave power generation device according to claim 4.

10. 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 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 added as rotational energy. The floating wave power generation device according to claim 9.

11. A first step of identifying an installation location on the sea where the mean water level is shallower than half the mean wavelength of the waves using a water level meter; a second step of fixing one end of the mooring portion to the seabed and attaching the other end of the mooring portion to a floating body, thereby floatingly positioning the floating wave power generation apparatus at the installation position; a third step of generating power using the floating wave power generation device installed at the installation position in the second step; and The floating wave power generation device is The floating body is provided with a wave inlet; a rotating body that includes 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 that have flowed in from the wave inlet channel with the plurality of wave receiving blades; a generator attached to the rotating shaft; a mooring member for mooring the floating body to the seabed in a state in which the floating body can float on the sea surface; and The wave receiving blades are rotated by the waves flowing in from the wave inlet channel, and the generator generates electricity based on the rotational force of the rotating shaft corresponding to the rotation. Power generation method.

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