JP2002332946A - High output wave activated power generation buoy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a high-output wave activated power generation buoy in which high output can be gained based on a small-sized buoy moored on the ocean, power unit price per output is extremely low, and control of over-input from stormy wave is rationally possible compared to a conventional highly efficient wave activated power generating device having obtained energy from motion of a buoy in relative to a fixed member. SOLUTION: A quasi sealed water chamber containing a large amount of sea water in a base buoy as an ocean station is provided, a natural vibration cycle of the base buoy is prolonged by using a large mass addition effect of this sea water for phase lag, and a new power generation method is obtained for high-output wave activated power generation from a relative motion with a short cycle buoy with a small phase lag and a short natural vibration cycle. By providing a difference in the horizontal cross section of a float chamber between a normal wave with small wave height and a stormy wave with high wave height, a large difference is generated in a buoyancy change by wave, and rational control on over-input is realized by considerably compressing the phase lag of the base buoy at a storm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wave power buoy capable of supplying high-output power to an offshore buoy moored particularly offshore from a coastal area. It can be used as a wave energy application device that can be easily installed on the sea surface where the water depth is deep, and it can be used not only for power generation but also for seawater desalination equipment, aquaculture, fishing, deep sea water utilization, seawater pumping power generation, etc. It can also be used as pump power.

[0002]

2. Description of the Related Art A conventional wave power buoy generates an air flow from the vertical movement of a wave and uses the generated air flow for driving an air turbine. This power was used to power the sign lights, but the output was very small and far from satisfactory. In this buoy for wave power generation, it is said that a portion directly related to power generation is small with respect to the size of the buoy, and the power generation efficiency is limited to about 5%. As a result of staying at such low power generation efficiency, conventional wave power buoys have had to be extremely expensive. As a countermeasure, we have heard that some buoys equipped with wind power and solar power have been considered, but if you try to avoid the effects of waves during stormy weather, you have to configure a large buoy, Similarly, large-sized buoys are inevitable for solar power generation in which a large output cannot be obtained unless a large light receiving area is secured.

The present inventor has also disclosed "Japanese Patent Laid-Open No. 2000-15577.
4 ”A small high-efficiency wave power generator has been newly proposed using the“ wave energy converter ”. However, since this device also requires a tower fixed to the sea floor, there is no limit to the water depth that can be installed as it is. Was.

As described above, it has been difficult to realize a high-output wave power buoy using an economical small buoy with the conventional technology.

[0005]

[Problems to be solved by the present invention] The problems to be solved by the present invention are based on the knowledge and know-how obtained by the inventor of the wave power generation demonstration plant near Muroran Port for many years, and the wave power generation. It is an object of the present invention to provide a low-priced, high-output small power generation buoy by realizing the buoy. It is an object of the present invention to provide a highly reliable small offshore power buoy which can continue to exhibit a sufficiently high output without maintenance for a long period of time on the sea isolated from the coast.

[0006]

The principle of wave power generation is to convert kinetic energy of a moving object excited by a wave into electric power. For efficient power generation, it is preferable to directly vibrate a moving object by wave power without using a medium such as air. Further, it is desirable to employ a method in which wave motion kinetic energy in both the vertical direction and the horizontal direction can be absorbed by a moving object. As a wave power generation system satisfying this condition, Japanese Patent Laid-Open No. 2000-15
No. 4774 has a wave energy conversion device. In addition, the solder duck system, the Bristol cylinder system in the UK, and the rotary buoy system in Korea are considered to be wave power systems with relatively high energy acquisition efficiency. In each of these methods, energy is absorbed from the relative motion of the moving object with respect to the fixed object, so that there is nothing to do without a fixed object serving as a basis for supporting the moving object. For buoys moored offshore, this problem must first be addressed. In addition, fixed objects are inflexible,
There are few means to limit excessive input in the event of a storm, and the excessive input tends to damage the power generator.

In order to solve this problem, the present inventor has proposed a long-period buoy, which has a large substantial mass instead of a fixed object, and has a remarkably dull swing response characteristic to ordinary waves, and, on the contrary, a light-weight buoy. Based on a combination with a short-period buoy that is composed of a floating body and has good response characteristics to ordinary waves,
For normal waves, long-period buoys create a large phase lag, thereby promoting the amplitude of short-period buoys, which are responsible for power generation, and allowing for greater output, while having long wavelengths when storms rush. For long waves, the long-period buoy reduces the relative amplitude between the two buoys by improving the response characteristics relatively and reducing the phase lag with the short-period buoy,
We have considered a new method that can limit excessive input during a storm by reasonably limiting the output of short-period buoys. In order to increase the mass of this long-period buoy, it is reasonable to take seawater itself into the buoy by the water chamber, and in the present invention, it can also serve as a fish reef to which seaweeds and shellfish can adhere. A semi-closed water chamber having an appropriate area and an appropriate number of openings was constructed. By appropriately selecting the dimensions of the water chamber, the natural oscillation period (7 to 9 sec) which is about 1.4 to 1.8 times longer than the normal wave having a wave height of 5 sec assumed to be about 1 m. Buoys can be easily designed. The point of this long-period buoy is that even if it is excited by a wave having a period of 5 sec, the amplitude is small in 5 sec-period and the phase is delayed, causing a phase delay. The natural frequency of the short-period buoy in which the difference in the amplitude becomes the effective amplitude is shorter than 5 sec and 2.5 to 4 sec. While the effective amplitude of the buoy increases, the effective amplitude between the two buoys, which have a small phase difference due to the small phase lag of the long-period buoy, also decreases in a storm wave with a strong excitation force. A wave power generation method capable of limiting excessive input can be easily realized. In this case, the short-period buoy does not generate self-excited vibration corresponding to the natural frequency, but means that it can follow the vibration of the wave without delay. Vibration motion synchronized with the waves. Further, the long-period buoy has a groove-shaped open water chamber opened in the front-rear direction in which the wave travels so that the movement of the short-period buoy is performed stably, and the short-period buoy is disposed inside the water chamber. did. In addition, the horizontal cross-sectional area of the floating chamber of the long-period buoy has a shape that changes as a function of the vertical direction. That is, the cross section has a small cross-sectional area in a portion that normally comes into contact with a wave, but has a large cross-sectional area in an underwater portion and an upper portion that is washed by a storm wave.

[0008]

The reason that the horizontal cross-sectional area of the long-period buoy is a function of the vertical direction due to such a shape is that in the range of normal waves, the action of the added weight in the semi-closed water chamber in the water is less than the influence of waves. This is because in a stormy wave, which works strongly and has a high wave height, the large buoyancy-enhancing effect of the floating chamber reduces the effect of the seawater added weight of the water chamber. While normal waves can generate power with high efficiency, storms mean that power generation efficiency drops significantly. The quasi-sealed water chamber of the long-period buoy has a large volume, and the motion of the long-period buoy has to involve most of the seawater in the quasi-sealed water chamber in the same oscillating motion as the buoy.
As a result, the vibration motion of the long-period buoy has the effect of making it dull, and the natural vibration period of the long-period buoy is 1.4 to that of the normal wave.
As a result, the period is extended by 1.8 times.

The above-mentioned long-period buoy is combined with a short-period buoy composed of a lightweight floating body, and the relative motion between the two buoys causes wave power generation of the power generation buoy. Not only can you obtain a nearly constant output in both normal and normal waves, but you can also reduce the need to increase the intensity in preparation for buoy storms. Furthermore, a long-period buoy that constitutes a platform base buoy on the ocean has a groove-shaped open water chamber with openings directed upstream and downstream in the normal traveling direction of waves, so that waves from different directions can be prevented. When the buoy rushes, the moored buoy naturally follows the new wave direction,
The buoy is always headed in front of the waves because of the effect of correcting the direction, which is advantageous for maintaining high power generation efficiency. In addition, since the short-period buoy is provided in the groove-shaped open water chamber, the light-weight short-period buoy is protected by the groove-shaped open water chamber, and only a wave in one direction acts.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail with reference to the accompanying drawings, in which: FIG. FIG. 1 is a perspective view of an embodiment of the present invention, and shows an entire state of a wave power buoy moored in a predetermined sea area by a mooring line 20 on the sea. In this embodiment, Japanese Patent Laid-Open No. 2000-1 proposed by the inventor described above.
Although the wave energy conversion device of No. 54774 is employed as a short-period buoy, other types of buoy structures devised in foreign countries which are considered to have good efficiency may be excluded from the present invention. It is not something to be done. However, the new technology proposed by the present inventor is based on a model experiment that can change the wave conditions in various ways. It has been confirmed that a considerably high energy acquisition efficiency of about 35 to 40% can be realized under the conditions described above. Therefore, this technology, which can reliably expect a power generation efficiency of 30% or more as a wave power buoy, is selected as an embodiment of the short-period buoy of the present invention. In the wave power buoy shown in FIG. 1, a long-period buoy 1 constituting a base buoy as an offshore platform has a box-shaped quasi-enclosed water chamber 15 also serving as a weight in the seawater below the buoy. A pair of floating chambers 12 and 12 fixed to both parallel side surfaces and extending parallel to the sea surface;
These form the basic structure of the long period buoy 1. A region surrounded by the pair of floating chambers 12, 12 and the upper surface of the water chamber 15 in seawater through which waves can pass constitutes a groove-shaped open water chamber 11 in which the short-period buoy 2 is provided. As shown in the figure, the semi-sealed water chamber 15 in seawater has six to nine holes of an appropriate diameter on one side surface. Seawater can enter and exit the water chamber through this hole, but the amount of water that can enter and exit during the swinging of the buoy 1 is limited and small compared to the total amount of water in the water chamber. Make up. With this hole, the water chamber 15 can replace a fish reef prepared for habitat of seagrass, shellfish, fish and the like. The groove-shaped open water chamber 11 provided at the center of the long-period buoy 1 has a floating chamber 12,
A pair of side plates 13, 13 is formed on the extension of the facing inner surface of 12, and covers the side surface of the floating body 9 that plays an auxiliary role with respect to the floating body 8 that is the main body of the short-period buoy 2.
Also serves as a protection plate. Since the side plate 13 is farther away from the center of the long-period buoy 1, the buoy 1 is easily given a moment, and plays an important role in that the opening of the water chamber 11 always faces the front of the wave. Long period buoy 1
At the top of the floating chamber 12, there are provided a power generator for generating electric power from the high-pressure water generated by the short-period buoy 2, a sensor for weather and oceanographic data, a wireless transmitter, a marker light, and the like. do not do.

FIG. 2 is a longitudinal sectional view of the entire power generation buoy when the grooved open water chamber 11 of the embodiment of the high power wave power generation buoy shown in FIG. 1 is viewed from the front, and FIG. Open water chamber 11
1 is a longitudinal sectional view of the entire power generation buoy when viewed from the side. FIGS. 2 and 3 also show the structure of the short-period buoy 2 in this embodiment so as to be roughly understood. Most of this power buoy is below sea level, and its foundation as a base buoy is in this subsea part. In FIG. 2, the floating chambers 12, 12 fixed to the upper end portions of the left and right side surfaces of the semi-sealed water chamber 15 located at the lower part and extending parallel to the sea surface, have grooves formed on the inner surface and the upper surface of the water chamber 15. Forming an open water chamber 11,
The short-period buoy 2 is connected to the inside. In this embodiment, the height of the semi-sealed water chamber 15 in the sea is 4.3 m, and the depth of the groove-shaped open water chamber 11 to the still water surface is 3.2 m.
The height from the still water surface to the upper surface of the floating chamber 12 is 2 m.
The subsea part of the long-period buoy 1 is 7.5 m, while the marine part is only 2 m. Since the lower box-shaped semi-sealed water chamber 15 has a large volume and can also serve as a weight, the posture of the long-period buoy 1 is stabilized in combination with the floating chamber 12 that generates buoyancy. Structure. The width of the water chamber 15 shown in FIG. 2 is 2.5 m, but it has nine holes of a suitable diameter, and the width of the water chamber 15 shown in FIG. Has holes. These holes are provided only on the side surface, and are not provided on the upper surface and the lower surface. The reason is that there is a possibility that the action of the water chamber 15 as an additional mass against the vertical movement of the wave may be reduced.

FIG. 2 most clearly shows a change in the cross section of a pair of floating chambers 12 extending in parallel to the sea surface. This central portion room 12-2 near static water level is the smallest thickness _{w 2,} the thickness _{w 1} of the upper chamber 12 - that is on the sea surface, the thickness _{w 3} of the lower chamber 12-3 underwater large thickness It has become. In the illustrated embodiment, the groove-shaped open water chamber 11 is used.
The spacing between the inner surfaces of the floating chambers 12 and 12 forming the
, And the thickness _{w 1} and _{w 3} of the upper chamber and the lower chamber is 0.7 m. The thickness of the w ₂ is about half that. w ₁ , w ₂ ,
w ₃ that has a shape having a variation such that this way function, by swinging the long period buoy 1 for normal wave suppressing buoyancy change in float chamber 12 to the low level, semi-sealed water chamber On the other hand, for the storm wave having a high wave height, a large change in buoyancy occurs in the floating chamber 12, and the mass adding effect of the quasi-enclosed water chamber 15 is reduced. Is to compress the phase lag of the short period buoy 2 so that the output of the short period buoy 2 can be naturally limited. Groove open water chamber 1
1, the width of the main floating body 8 of the short-period buoy 2 which is responsible for the power generation action of the power generation buoy is 2 m, and as shown in FIG. It is dimensioned to catch most wave power.

FIG. 3 is a sectional view showing the main structure of the short-period buoy 2 in this embodiment. As mentioned earlier,
This embodiment does not limit the structure of the short-period buoy of the present invention, and other types can be adopted. However, it is shown as a preferable example in which reliable high-power generation can be expected even under a wide range of wave conditions. . The floating body 8 arranged substantially at the center of the groove-shaped open water chamber 11 is the main body of the short-period buoy 2 and is moored at the center of the water chamber 11 by the link 3 having a length equal to or greater than the assumed wave height. The link 3 is connected to the floating body 8 by the connecting shaft 5, while being connected to the long-period buoy 1 by the connecting shaft 4 at the other end. The link 3 has pumps 6 at both ends.
A pump 7 is provided, and the connecting shafts 4 and 5 are respectively provided with pumps 6
And the pump shaft of the pump 7. The floating body 8 can simultaneously perform two kinds of motions, that is, right and left swinging about the axis 5 and up and down swinging about the axis 4, and absorb kinetic energy of up, down, left and right waves having different phases. Can be prepared. Further, the floating body 8 is characterized in that an auxiliary floating body 9 is connected to a position separated by a connecting plate 10, and the auxiliary floating body 9 realizes a natural oscillation period shorter than a normal wave. . The floating body 9 gives a strength to the horizontal swinging moment of the floating body 8 by completely sinking into the seawater or completely jumping out of the sea surface by the swinging of the floating body 8 in the left-right direction. The force in the return direction, in which the force of the vibration is weakened, is urged to shorten the natural oscillation period. The floating body 8 has a substantial height of 2.8 m, a width of 2.0 m and a thickness of 0.5 m. The dimensions of the floating body 9 conform to the dimensions of the floating body 8. The length of the link 3 is 3.0 m, and the distance between the floating bodies 8 and 9 is also 3.0 m. In addition, a generator or the like that generates electric power from high-pressure water generated by the pump 6 and the pump 7 is disposed inside the upper chamber 12-1 of the floating chamber 12. The protective structure is provided inside the link 3, the connecting shafts 4 and 5, and is not exposed to waves at all. Above the groove-shaped open water chamber 11 of the long-period buoy 1, both inner surfaces project 1.5 m forward, and the connecting shaft 4 is fixed at the front end thereof. At the rear of the groove-shaped open water chamber 11, the inner surface of the floating chamber 12 is the longest part.
Since the side plate 13 extended by 3 m extends to cover the side surface of the floating body 9 completely, and the distance from the center of the long-period buoy 1 is long, it is easy to change the direction of the buoy when the direction of the wave changes. The posture control in which the opening of the open water chamber 11 always faces the front of the wave can be naturally performed. The total length of the groove-shaped open water chamber 11 including the portion projecting in the front-rear direction is 6.8 m, and a pair of projecting portions is provided at the front end and the rear end thereof with connecting portions for connecting with each other. Increases mechanical strength.

The basic principle of the present invention is to combine a long-period buoy 1 having a long natural oscillation period and a short-period buoy 2 having a short natural oscillation period, so that a large phase difference allows a substantial wave to be applied to a normal wave having a low energy density. In the case of stormy waves with intense energy density, the difference in natural frequency is reduced to reduce the phase difference between two buoys and the relative amplitude of storm waves. The goal is to increase the overall amplitude and limit the input of excessive energy by reducing efficiency. Since such a power generation system in a power generation buoy is a new power generation method, based on the structural description of the above-described embodiment, the starting equation of motion of the floating body is again used, and a solution of a mathematical model is obtained. The characteristics of the power generation buoy in the present invention will be described in detail.

In mathematically expressing the movement of the floating body or buoy of the present invention, only the vertical movement of the floating body or buoy will be described for simplicity. That is, when the floating body is vibrated by waves and moves up and down, the movement of the floating body is as follows.

## EQU1 ##

[0016]

(Equation 1)

[0017] Σm wherein: the mass of the moving portion including the additional mass of seawater z: static floating body vertical displacement relative to the c: resistance coefficient K: coefficient of restitution F _z: excitation force due to the wave amplitude omega: Angular velocity when wave motion is regarded as circular motion t: time

The above equation of motion

The solution of Equation 1 is represented by z, the amplitude of the floating body: A _z , and the phase delay: Φ
When the damping coefficient:

[Equation 2],

[Equation 3],

[Equation 4],

It can be expressed by the following equations.

[0019]

(Equation 2)

[0020]

(Equation 3)

[0021]

(Equation 4)

[0022]

(Equation 5)

For each of these equations, the angular velocity corresponding to the circular period of the normal wave: ω _nor = 1.257 rad / sec
(However, the circular cycle T _nor = 5.0 sec, the wave height H = 1 m), and the angular velocity corresponding to the circular cycle of the storm wave on one side: ω _stom = 0.2683 rad / sec (the circular cycle T _stom = 10.0 sec) , Wave height H = 4m)
If a simulation is to be performed for the case described above, the angular velocity ω _z corresponding to the natural vibration period of the buoy has the following values for the normal wave and the storm wave of the long and short period buoy. Angular velocity corresponding to the natural oscillation period of the long-period buoy 1: ω _z1
= 0.817 rad / sec (Natural oscillation period T _z1 = 7.7 sec, H = 1m for normal wave) Angular velocity corresponding to the natural oscillation period of the long period buoy 1: ω _z1
= 1.16 rad / sec (Natural oscillation period T _z1 = 5.4 sec, H = 4 m Storm wave) Angular velocity corresponding to the natural oscillation period of the short-period buoy 2: ω _z2
= 2.01 rad / sec (equivalent vibration cycle T _z2 = 3.1 sec)

Further, the value of the damping coefficient ζ is obtained as follows. Long period buoy: ζ _z1 = 0.5 (normal time), ζ _z1 = 0.
354 (at the time of storm) Short-period buoy: ζ _z2 = 0.24

[0025] Under the conditions described above, the long period buoy 1 and the normal wave are short period buoy 2 and the short-period waves, and the amplitude A _z of the buoy when it is vibrated by the wave storm a long period wave The value of the phase delay Φ is determined, and the effective amplitude determined by the relative amplitude of the two buoys and related to the effective value of the power generation amount: A _ze = A
The value of _z2 - _Az1 is determined and these are

Table 1 summarizes the results.

[0026]

[Table 1]

This simulation is summarized

According to Table 1, the difference in phase lag between the long-period buoy 1 and the short-period buoy 2 is as large as 104 ° under normal conditions, so that the effective amplitude is large even if the wave height is small. The phase difference is remarkably small at 16 °, and the excessive input is naturally limited so that the effective amplitude is also at the same level as in the normal state. That is, when the wave height is 1m or 4m,
This means that the automatic control operation for keeping the power generation output substantially constant is performed naturally, which is the greatest feature of the present invention. Next, when an angular velocity ω _z corresponding to the natural oscillation period is given, a relational expression for obtaining a necessary moving part mass Σm is as follows.

Since Σm is inversely proportional to ω _z ² , it can be easily understood from the simulation result that the mass of the buoy having a small angular velocity ω _z is very large.

[0028]

(Equation 6)

Here, the restoration coefficient K is expressed by the following equation.

## EQU7 ##

[0030]

(Equation 7)

Here, ρ _w : density of seawater g: acceleration of gravity A _wp : horizontal sectional area of the floating chamber at z coordinate

The long-period buoy 1 of the present invention is obtained by seawater in which most of the kinetic mass is captured in the semi-closed water chamber 15.

As is apparent from the relational expression, the restoration coefficient K which is a factor that determines the angular velocity ω _z in relation to the moving part mass Σm
Is also a function of the horizontal sectional area A _wp of the floating chamber 12, so that if this A _wp changes, ω _z can also be changed. Change in thickness of the float chamber 12 shown in Figure 2, that with a change in the coefficient of restitution K can alter the angular velocity omega _z, not only qualitative description of the, as a quantitative easily understandable even I have. The semi-closed water chamber 15 can change the mass of the moving part of the entire buoy widely by changing the size of the water chamber, so that there are both effects of saving materials and expanding design freedom. In addition, a large amount of seawater inside the semi-sealed water chamber 15 enters into the interior when installed on the sea, and is empty when producing a buoy on land or transporting it to the installation sea surface. Needless to say.

The above

Among the simulations whose results have been shown in Table 1, the effective amplitude A, which is the relative amplitude of the two buoys in particular,
FIG. 4 is a graph showing _ze, taking the horizontal axis as the time axis, and taking the effective amplitude of the buoy and the amplitude of the waves on the vertical axis. In the graph of FIG. 4, the curve indicated by the solid line indicates a normal wave having a wave height of 1 m, and the wave period is 5.0 sec and the amplitude is ± 0.5 m. The angular velocity ω is 1.257 rad / sec. One storm wave is represented by a curve shown by a broken line, and has a period of 10.0 sec and an amplitude of ± 2.0 m. The angular velocity ω is 0.6283 rad
/ Sec. When these two waves are compared, the amplitude (wave height) of the storm wave is four times that of the calm normal wave, and the waves rushing at the doubled period are extremely rough waves. The wave input to the power generation buoy is such a wave, but the wave power buoy illustrated as an embodiment of the present invention represents the effective amplitude _Aze from the relative movement of the two buoys, and the dashed line is a solid line. The effective amplitude obtained from the indicated normal wave is shown. The dash-dotted line curve has the same cycle as the normal wave, but the phase is shifted, so the effective amplitude is ± 0.8 m, and the effective amplitude related to the power generation amount is larger than the original normal wave. . This does not violate the law of conservation of energy. The energy added to the short-period buoy is added to the energy added to the short-period buoy, so that such high efficiency can be realized.
The two-dot chain line curve with respect to the storm wave curve shown by the other broken line is a curve representing the effective amplitude of the wave power buoy according to the embodiment of the present invention at the time of the storm.
c, but the effective amplitude of the phase-lagged curve is ± 0.8 m, which greatly limits excessive input from severe storm waves,
As a result, the same effective amplitude as that of a normal wave is realized. From FIG. 4 as well, the advantages of the new wave power generation method of the present invention, which is particularly suitable for a small power generation buoy, can be fully understood.

At the end of the description of the embodiment of the present invention, the specifications of the wave power buoy having the dimensions shown in FIGS. 2 and 3 will be described again. * Sea surface conditions assumed in the illustrated embodiment Wave height of significant wave: 1.5 m, period of significant wave: 5 sec, average power of incident wave: 9 kW Maximum power of incident wave: 15 kW (however, per 2 m width of short period buoy) * Specifications of wave power buoy Long period buoy: angular velocity ω corresponding to the natural oscillation period of normal waves
_z1 = _0.817rad / sec angular velocity ω _z1 = 1.1, which corresponds to the natural vibration period of the wave of the storm
6 rad / sec Mass of moving part Σm = 36,300 kg (buoy body = 6, 3
00 kg, additional water in water chamber 15 = 30,000 kg) Restoration coefficient K at normal time = 24,240 kg / sec ² Restoration coefficient K at storm = 48,480 kg / sec ² Short-period buoy: equivalent to natural oscillation period Angular velocity ω _z2 =
2.01 rad / sec Mass of moving part Σm = 2,500k
g (buoy body = 2,000 kg, additional water = 500 kg) Restoration coefficient K = 10,100 kg / sec ² * Generator capacity 3 kW

[0035]

According to the new buoy high power wave power generation method suitable for a small offshore buoy according to the present invention, the method can be applied to a natural wave having a low energy density on a natural sea surface where the input energy density changes extremely. Is based on a long-period buoy with a large phase lag and as the base buoy, the relative amplitude of the long-period buoy with a small phase lag as the effective amplitude of wave power generation,
While it is possible to substantially increase the efficiency of energy acquisition, for storm waves with excessive energy density,
By greatly compressing the phase lag and greatly reducing the relative amplitude between the long-period buoy and the short-period buoy, the energy acquisition efficiency is significantly reduced, and it is possible to extremely reasonably limit excessive input. The large phase lag of this long-period buoy is caused by the effect of the added mass created by incorporating a large amount of seawater itself into the buoy. The buoy water chamber that contains seawater has an appropriate diameter and number of holes and takes in seawater when the buoy is installed on the sea surface.Therefore, the water chamber has a very high degree of freedom in design and is easy to manufacture and transport. ,
Costs can be kept low. As a result, according to the high-output wave power generation method of the present invention, in a wave power buoy utilizing natural energy having a remarkable change in energy density, a reasonable automatic output control that keeps the power generation output almost constant is naturally achieved. can do. This point is a new effect that could not be realized at all by the conventional wave power generation system, and is a distinctive feature. By fully utilizing the features of the present invention, even a small buoy installed on the ocean can generate sufficient output power, so the cost per output is extremely low as compared with the conventional wave power buoy. In addition, the reliability of the small high-output wave power buoy on the sea, which is difficult to maintain, can be raised to a sufficiently practical level. As another side effect, the water chamber of the buoy of the present invention has a seaweed, shellfish,
It can also be used as a reef suitable for breeding fish and the like. Conventionally, even when buoys are installed on the sea surface, fishermen are strongly opposed, and the guarantee of fishing rights has been a social burden.
Combined with artificial reefs in large-scale seawater in Kairi's economic waters, artificial formation of fishing grounds is possible, which can help solve this problem. Further, according to the high-output wave power buoy of the present invention, since its total energy output utilizes natural energy, the environmental conservation effect is extremely high. The long-period buoy of the present invention suppresses the amplitude of ordinary waves by the added mass of a large amount of seawater in the water chamber, so that it can be easily used as an offshore station. It will be able to be installed in places where a large number of these units are required. It is thought that this offshore station can further increase application fields such as observation.

[Brief description of the drawings]

FIG. 1 is a perspective view of a high-power wave power buoy according to an embodiment of the present invention moored offshore at a mooring line.

FIG. 2 is a longitudinal sectional view of the entire power generation buoy when the groove-shaped open water chamber of the embodiment of the high power wave power generation buoy shown in FIG. 1 is viewed from the front.

FIG. 3 is a longitudinal sectional view of the entire power generation buoy when the groove-shaped open water chamber of the embodiment of the high power wave power generation buoy shown in FIG. 1 is viewed from the side.

FIG. 4 is a graph showing changes in simulated values of the effective amplitude of a buoy with respect to a normal wave having a height of 1 m and a storm wave having a height of 4 m, with a horizontal axis representing a time axis and a vertical axis representing a wave height and a buoy effective amplitude. 7 is a curve graph showing the change in wave height by comparing the phase delay of the buoy effective amplitude.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Long-period buoy 2 Short-period buoy 3 Link 4 Connecting shaft of long-and-short-period buoy also serving as pump shaft 5 Connecting shaft serving as pump shaft and connecting link and main floating body of short-period buoy 6 Pump 7 Pump 8 Short Floating body that is the main body of the periodic buoy 9 Auxiliary floating body of the short-period buoy 10 Connecting plate of the main-slave floating body of the short-period buoy 11 Slot-shaped open water chamber 12 A pair of floating chambers extending in parallel from the sea to the sea surface 12-1 Floating Upper room of the room 12-2 Central room of the floating room 12-3 Lower room of the floating room 13 Side plate 15 Semi-sealed water room in the sea 20 Mooring of buoy

Claims (4)

[Claims] 1. While constituting a platform as a moored base buoy, while having a natural oscillation period of about 1.4 to 1.8 times the normal wave period generated on the installation sea surface, it responds to normal waves. A combination of a long-period buoy having a difficult response characteristic and a short-period buoy having a good response characteristic to a normal wave by having a natural oscillation period of about 0.5 to 0.8 times the normal wave period, High power wave power generation method for buoys, comprising means for absorbing wave power energy from relative movement of two buoys 2. While forming a platform as a moored base buoy, the lower part has a quasi-enclosed water chamber which substitutes for a weight, and this quasi-enclosed water chamber has an appropriate area and number of openings, A long-period buoy having a natural oscillation period of about 1.4 to 1.8 times the normal wave cycle by having a floating chamber at the top, and a light-floating chamber with a 0.5 to 0 normal wave cycle. .8
A high-power wave power buoy comprising a short-period buoy having twice the natural oscillation period, a connecting shaft connecting the two buoys, and a power generator including a pump on the connecting shaft. 3. The long-period buoy includes an upper surface of the semi-sealed water chamber in seawater, and a pair of floating chambers having lower portions fixed to opposing side surfaces of the semi-sealed water chamber and extending parallel to the sea surface. The high power wave power generation buoy according to claim 2, comprising a groove-shaped open water chamber configured and opened in the front-rear direction of the wave traveling, wherein the short-period buoy is arranged in the water chamber. 4. The size of the horizontal cross-sectional area of the floating chamber of the long-period buoy constitutes a function in the vertical direction, has a constant area after gradually increasing from below, and in a range where a normal wave moves up and down. 4. The high power wave power buoy according to claim 3, wherein the buoy has a small cross-sectional area, but has a large cross-sectional area again at a higher position where it is washed by storm waves.