JPH02230970A - High-performance wave activated power generating buoy - Google Patents

Abstract

PURPOSE:To effectively utilize the wave power and generate a high electric power output by forming an oblong floating body section with a pigeon breast- shaped cross section, providing a power generating device constituted of an air turbine and a power generator on the floating body, and connecting it to an air chamber. CONSTITUTION:A floating body section 1 has a pigeon breast-shaped cross section. An air chamber 2 is provided at a position separated from the floating body section 1, and a horizontal duct 3 communicated to it and opened at the terminal is fitted below it. A power generating device constituted of an air turbine 5 and a power generator 6 is provided on the floating body section 1 and connected to the air chamber 2. The large pitching motion of the floating body section 1 caused by waves is utilized to convert the air output of the air chamber 2 into electric power. A high electric power output can be generated accordingly.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a high-performance wave power generation buoy, which can be used not only as a small power generation buoy but also as a large wave power generation device, and can generate electricity by wave power. It can be generated economically and can be used not only as a navigational aid but also as a power generation source on remote islands and on land where transportation is inconvenient. [Prior Art] Wave power generation devices that are currently in practical use as small power generation buoys are wave power generation buoys for navigational aids, and one example of this is shown in Figure 7, in which a buoyant body A long cylindrical central pipe with a bottom opening is provided at the center, an air chamber is formed above the central vibe, and a valve box containing an air turbine and a generator is formed at the upper center of the air chamber. Additionally, four valves for controlling air passages are installed around the outer circumference of the valve box. The small power generation buoy has a central pipe length of approximately 4 m, and when the nozzle squeeze ratio (nozzle area/air chamber area) = l/100, the peak of the specific pressure (air chamber pressure head/wave height) is 0.3.
It demonstrates this performance. One example of a practical experiment as a large-scale wave power generation device is the ``Kaimei'' experiment conducted by the Japan Marine Science and Technology Center off the coast of Yura, Tsuruoka City, Yamagata Prefecture. Kaimei is 80mX12mX
The length of the ship is 5.5 m, which is longer than the wavelength, and is formed into an immovable floating body, moored on the sea surface facing the direction of the waves, and the bottom of the floating body is opened to accommodate a number of air chambers in parallel. The system generates electricity using an air turbine and a generator using airflow controlled by valves. Kaimei's experimental results showed a specific pressure of 0.1 to 0.15. Another example of a large wave power generation device is shown in Figure 8. It has a short bottom plate-like air chamber with openings on the front and sides of the hull with a length equal to the wavelength,
It rotates an air turbine generator by receiving waves coming from the front or side. The specific pressure is squeeze ratio 1/1
Under the conditions of 00, it is 0.3 (bow) to 0.15 (ship side), but it has the disadvantage that the mooring force is about three times that of Kaimei. A highly improved high-performance wave power generation buoy compared to these conventional techniques has been proposed in Japanese Patent Application Laid-Open No. 62-233483. The high performance of this buoy was confirmed in an aquarium experiment, and subsequent sea trials were conducted with good results. What was tested at sea was a single-hulled and two twin-hulled duct buoys with a length of 2.
, 3m. It has a high conversion efficiency that converts 100% of the wave energy of the width of the floating body into air power with a wave period of 2.3 seconds. The feature of this buoy is that the floating body length is about 0.4 of the wavelength, and the power generation output peaks at the pitching period of the buoy and the resonance period of the horizontal duct. Currently, its main use is as a power source for offshore buoys such as telemeter buoys, but the biggest goal is to use it as a power source for remote islands. An example of a large wave power generation device is shown below. This buoy has a length of 36 m in the direction of the waves, a floating part of 30 m in length, and a width of 36 m.The total weight of the buoy is approximately 1000 tons, and the unit power generation cost is 15 to 20 yen on the British coast where waves are high. It is calculated as yen/kwh. However, this is too expensive compared to other power sources, and considering its use in low-wave oceans like Japan.
There is a strong demand for smaller equipment, increased output, further improvements, and cost reduction. As a prior art related to the present invention, Figure 11 shows the floating shape of a British salter duck. This is known as a highly efficient wave power generation device that generates a large oscillating motion, but the oscillating motion is generated by turning a hydraulic turbine into four-turn power output using a gyro installed inside. ．． Also shown in Figure 12 is a pendulum-type wave power generator, which has an underwater inertial body at the bottom and front of the circular floating bottom and a counterweight at the bottom and rear, and generates a powerful pitching motion by waves. Although the salter duck and pendulum types mentioned above have not been put into practical use, they have undergone sufficient basic tests and experiments on lakes and seas. [Problem to be solved by the invention] A conventional example of 3000k with a length of 36m shown in FIG.
A design example of a large wave power generation device in a backward bending buoy is as follows.
The length of the floating body is short at 0.4 of the wavelength, which is an improvement over Kaimei and others, but in order to achieve economic efficiency, a smaller buoy and higher output are required. The present invention meets this need and aims to generate higher power generation output with a floating body that is extremely short, 0.04 to 0.06 times the wavelength. [Means for solving the problem] The high-performance wave power generation buoy of the present invention has the following configuration as a means for solving the above problem. (1) Consisting of a substantially vertical air chamber moored to the sea surface, a horizontal duct with an open end communicating with the air chamber via a curved part, and a floating body fixed on the horizontal duct, A power generation chamber consisting of an air turbine and a generator is provided in the air chamber, and the floating body is an oblong body located at a position away from the air chamber,
The top surface is horizontal, and the bottom surface has a cross-sectional shape that changes from a large curvature at the rear to a small curvature at the front (pigeon chest shape). (2) In (1) above, the lateral length of the floating body is approximately 0.04 to 0.06 times the maximum wavelength on the sea surface. (3) The length of the horizontal duct in (1) above, including the air chamber, should be approximately 0.0 mm of the maximum wavelength at the sea surface. Make it 4 times. (4) Instead of the floating body having a pigeon-chest shape on the bottom surface in (1) above, the floating body has a circular bottom surface and underwater inertia bodies and heavy objects are attached to the front and rear. (5) The lateral length of the floating body in (4) above is approximately 0.04 to 0.06 times the maximum wavelength on the sea surface. (6) The length of the underwater duct in (4) above, including the air chamber, should be approximately 0.00 mm of the maximum wavelength at the sea surface. Make it 4 times. (7) Two air chambers moored to the sea surface in a substantially vertical direction, front and rear, horizontal ducts that communicate with the lower parts of the front and rear air chambers via each curved part, and upper air that communicates between the upper parts of the front and rear air chambers. a passageway, and a floating body fixed on the horizontal duct; water is sealed in the horizontal duct so that a water column is centered in both air chambers; and a power generation device consisting of an air turbine and a generator is installed in the upper air passageway. The floating body is an oblong body located in the middle of a horizontal duct apart from the front and rear air chambers, and has a horizontal top surface and a curved bottom surface that changes from a small radius of curvature at the rear to a large radius of curvature at the front (pigeon chest shape).
It must have a cross-sectional shape consisting of: (8) The lateral length of the floating body in (7) above is approximately 0.04 to 0.06 times the maximum wavelength on the sea surface. (9) In (7) and (8) above, the front and rear air chambers are provided adjacent to the oblong floating body to further shorten the length of the device in the wave direction. (10) In (9) above, the lower or side surfaces of the front and rear air chambers are opened to seawater to further simplify the process. In order to do this, a strong pitching motion can be generated by adopting a pigeon-chest cross-sectional shape of the floating body as in the prior art Salter duct buoy, or a floating body as in the prior art pendulum type wave buoy. By attaching an underwater inertial body suspended by a cable to the lower front end of the floating body and a counterweight to the lower rear end, the vertical motion of the waves can be extracted as the pitching motion of the floating body. This reduces the length of the floating body to 10 m or less, whereas the floating body of a large wave power generator with a length of 30 m shown in Figure 1 is required to match the wave period of approximately 9 seconds. This not only greatly reduces the weight and construction cost of the floating body, but also strengthens the pitching motion. On the other hand, when fixing the air chamber and the open-ended horizontal duct connected to it to the shortened floating body, the pitching movement can be amplified by positioning the air chamber ahead of and away from the pitching buoyant body. This is taken up as the relative motion of waves in an air chamber. This width increase makes it possible to reduce the length of the air chamber and the open-end horizontal duct in the direction perpendicular to the wave traveling direction (the width of the duct), as shown in Figure 8. This makes it possible to significantly reduce the weight and construction cost of the machine. Furthermore, as one design, the rear end of the horizontal duct with an open end is bent in a nearly vertical direction, and by placing an air chamber spaced at a distance behind the floating body here, the floating body This amplifies the pitching motion of the water in the horizontal duct, and generates air pressure that is in the opposite phase to the air chamber due to its relative movement with the water in the horizontal duct, thereby operating the air turbine more efficiently. Separating the air chamber from the oblong wave body greatly increases the relative motion of the air chamber with the waves, thereby reducing the amount of force inside the air chamber. However, another way to think about it is to make the air chamber almost the same as that of the oblong floating body, and instead place the air chamber adjacent to the floating body. Similarly, the front and rear air chambers each have their lower or side surfaces open to the seawater, and it is also possible to absorb the pitching motion caused by the pigeon-chest shape of an oblong floating body or the action of an underwater inertial body as air output in each air chamber. [Embodiment] FIG. 1 is a perspective view showing an example of an embodiment of the present invention, in which a floating body part 1
is a pigeon-chest type floating body with a cross-sectional shape that pitches best in the highest number of waves on the sea surface where the buoy is floating. An air chamber 2 attached in combination with this is located in front of the floating body part 1 and is placed apart from it, and a horizontal duct 3 with an open end communicating with this is attached to the lower surface. Furthermore, the length of the floating body part 1 in the direction perpendicular to the waves is long, while the length of the duct in the same direction is short. In the conventional model, the length of the floating body including the air chamber was chosen to be 0.4 of the wavelength, which was a major improvement over the Kaimei model, which required a length equal to the wavelength. However, in order to obtain economical wave power generation, the floating body part l is designed to have a pigeon-chest shape. As shown in Fig. 11, the rear face of the wave has a circular cross section with radius a centered at A, and the front face has a circular cross section with radius b slightly longer than a centered at B. The swinging motion centered on A due to the waves is induced by the change in the buoyancy of the front bulge caused by the waves.
As a result, even if the length of the floating body is shortened to 1/22 #0.045 of the wavelength, it is possible to obtain a structure with a stronger pitching force when compared to the box-shaped floating body shown in Figures 7 and 8. however. 0.045 is for optimal conditions, and in practice it is 0.0
The range is 4 to 0.06 times. According to research results from the University of Edinburgh in the UK, the floating body length is 10
The floating body with a pigeon-chest cross-section of 1.5 m is freely floating and generates a powerful oscillating motion that absorbs more than 50% of the energy of waves with an extremely long wavelength of 12 seconds, and has a wide response period width of 5 to 12 seconds. have. A 12 second wave has a wavelength of 220 m, so if a box-shaped floating body like the one shown in Figure 8 is used, the length of the buoy would be 220 m x 0.4 = 88 m. The advantage of adopting a pigeon-chest-shaped floating body cross section is that it only needs to be 10 meters long, and another advantage is that the periodic width of the response becomes wider. On the other hand, air chamber 2 and horizontal duct 3 have a problem with the vibration frequency of the water column inside the duct. Now, when the length of the water column in the duct is L, the natural vibration period T2 of the water column in the duct with one fixed end opened underwater is T. =12
Seconds. Also, at L=24m, T. = 9.8 seconds. On the other hand, the dimensions of the back-bending duct buoy shown in Figure 8 are designed with a pitching period T of 9 seconds. In order to obtain high output at pitching period -a, the natural vibration period T2 of the water column in the duct must be set to T. <T2, and the water column inside the duct is designed under conditions where it does not move or resonates. Therefore, in the case of Figure 1, the desirable dimensions are a floating body length of 10 m and a duct length of 24 m to 36 m. The air chamber 2 is conveyed through this long duct 3, and the floating body l
It is located further away and in front. As a result, the relative motion with the waves in the air chamber 2 is amplified by the oscillation motion induced by the floating body part 1, and a larger air pressure can be generated. Since the power generation output is proportional to the square of the relative motion with the waves in the air chamber, the length of the air chamber or duct in the direction perpendicular to the direction of wave propagation can be shortened.
In addition, the materials and construction costs required for the horizontal duct 3 can be reduced. The air pushed and pulled by the water surface in the air chamber passes through the air passage 4, rotates a Welsh-type air turbine 8, and generates electricity by a generator 6. Figure 2 shows a situation where the pitching motion of the floating body part 1, which has a pigeon-chest shape, is amplified at the position of the air chamber 2. Figure 3 shows another example. In this case, the cross-sectional shape of the floating body part 1 may be circular, but the water packet 7 suspended at the lower front has a large mass of water, making it difficult to move when being salvaged, while the counter mounted at the lower rear Weight 8
acts to return floating body part 1 to its original position. This is one way to downsize the floating body part l, which causes oscillating motion due to waves. The air chamber 2, horizontal duct 3, air passage 4, Welsh air turbine 5, and station 141116 are the same as in Fig. 1 except for the principle of inducing the pitching motion of the floating body. Figure 4 shows another embodiment in which the air chamber 1 and horizontal duct 2 are improved. In the embodiments shown in FIGS. 7 and 3, the horizontal duct 2 has its rear end open into the water. However, the length of the horizontal duct 2 is required to be between 24 m and 36 m under the condition of (pitting period T, of the floating body part) < (resonant period T. of water in the horizontal duct), and if When T2>T, the water generally moves and the air pressure does not increase. This is clearer than the example of the prior art shown in FIG. 5, in which the air pressure suddenly decreases due to the shortening of the length of the central pipe in the central pipe buoy. However, the desire for smaller size and lighter weight also strongly calls for some kind of improvement in reducing the length of the horizontal duct. The one shown in Figure 4 is an example of this as a countermeasure, and the horizontal duct 3 is longer than the floating body length of the floating body part l, but is 24 m.
It is shorter than ~36m, and the natural vibration period of the water in the duct is also shorter than the swing period of floating body part l. However, the rear air chamber is shaped by bending the terminal upwards instead of opening it to seawater. The period of vibration of the U-shaped tubes crossed in this way is, and even if the length of the water column is 16 m, T is 5.
．． This is 7 seconds, which is shorter than the oscillation period of floating body part 2. The air pressure in the front and rear air chambers, which move up and down due to the oscillation of the floating body 2, is low in each chamber due to the movement of the opposing water surface, but due to the upper air passage 4 The two air chambers 2 and 9 connected to the turbine 5 have opposite phases, so they act as a sum. It goes without saying that the rear air chamber 9 is also located away from the buoyant body 1 in the same way as the front, thereby making it possible to utilize the oscillating motion to a greater degree. What is shown in FIG. 5 is a variation of the embodiment of FIG.
The front air chamber 2 and the rear air chamber 9 are arranged adjacent to the floating body part l. Therefore, the vibration frequency of the water column in horizontal duct 3! tll T. becomes shorter than the pitching period T of the horizontally elongated floating body part 1. Under the condition T1>T, the water column is not stationary but moves and stops at a position where the difference in the water column is equal to the air pressure, which means that the specific pressure is slightly lower. An extreme example of this is the condition in which the lower surfaces of the front air chamber 2 and the rear air chamber 9 are open to seawater, as shown in Figure 6. BaT
s = 2.2 seconds, and the water column moves quickly and balances at a certain pressure. Under these conditions, the maximum air pressure is around 0.2 in terms of specific pressure, but as explained earlier, the two air chambers act to reverse the phase of each other, and the difference in air pressure becomes the sum. The effect of locating the air chamber away from the center of motion of the floating body makes it possible to increase the air output. As explained above, not only the length of the floating body part l is greatly reduced, but also the length of the air chamber and duct in the direction perpendicular to the wave, and furthermore, the length of the air chamber is increased to the outside of the floating body part. The length can be reduced to the extent that they can be kept apart, and the output can be improved by making the swinging motion more powerful.This will reduce the power generation cost of wave power generation, which currently costs 20 to 15 yen per KWH, to 7 yen per KWH. The goal is to create a small model for use on remote islands, as shown below. [Effects of the Invention] (1) By using a horizontally elongated floating body and making its cross-sectional shape pigeon-chested, the length can be shortened and wave power can be used effectively. (2) By using a horizontally elongated floating body with a circular cross-sectional shape and attaching an underwater inertial body and heavy objects to the front and rear, the length can be shortened and wave power can be used effectively. (3) Pitching motion can be amplified by placing the floating body part on a horizontal duct away from the air chamber. (4) A static chamber is provided at the front and rear, and the upper and lower sections are
By communicating with the horizontal duct through the upper air passage, the phase difference between both air chambers can be effectively utilized.

(5) By arranging the front and rear air chambers adjacent to the oblong floating body, the length of the floating body can be shortened, and further miniaturization can be achieved by opening the bottom or side of each air chamber to seawater. be measured.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a first embodiment of the present invention, and FIG. 2 is an explanatory diagram of its operation. Figure 3 shows the second implementation example and the fourth implementation example.
The figure is a sectional view of the third embodiment, FIG. 5 is a fourth embodiment, and FIG. 6 is a sectional view of the fifth embodiment. Also the 7th
Figures 1 to 12 are drawings showing conventional examples. The symbols in the diagram indicate the following parts. l: Floating body part 2: Air chamber 3; Horizontal duct 4: Air passage 5: Air turbine 6 Two generators: Water packet: Counter weight

Claims (1)

[Scope of Claims] 1. A horizontally elongated body moored on the sea surface with respect to the waves, with a horizontal upper surface, a circular lower surface, and a cross-sectional shape consisting of a curved surface (pigeon chest shape) that changes from a small radius of curvature at the rear to a large radius of curvature at the front. a floating body having a floating body, a substantially vertical air chamber provided at a position remote from the floating body, a horizontal duct with an open end communicating with the air chamber via a curved part, and an air turbine and a power generation unit mounted on the floating body. 1. A high-performance wave power generation buoy, characterized in that a power generation device consisting of a generator is provided and connected to an air chamber, and the air output of the air chamber is converted into electric power by utilizing the large pitching motion caused by the floating body due to waves. 2. A high-performance wave power generation buoy, characterized in that the lateral length of the floating body according to claim 1 is about 0.04 to 0.06 times the maximum wavelength on the sea surface. 3. A high-performance wave power generation buoy, characterized in that the length of the horizontal duct according to claim 1, including the air chamber, is approximately 0.4 times the maximum wavelength on the sea surface. 4. It is moored on the sea surface and has an oblong shape with a horizontal upper surface and a circular lower surface, and has an underwater inertial body such as a water bucket on one side of the lower surface and a heavy object on the other side. It consists of an attached floating body, a substantially vertical air chamber provided at a position remote from the floating body, and a horizontal duct with an open end communicating with the air chamber via a curved part, and an air turbine and a power generation unit are mounted on the floating body. 1. A high-performance wave power generation buoy, characterized in that it is equipped with a power generation device consisting of a generator, and converts the air output of an air chamber into electric power by utilizing the large pitching motion caused by the floating body due to waves. 5. A high-performance wave power generation buoy, characterized in that the lateral length of the floating body according to claim 4 is about 0.04 to 0.06 times the maximum wavelength on the sea surface. 6. A high-performance wave power generation buoy, characterized in that the length of the horizontal duct according to claim 4, including the air chamber, is about 0.4 times the maximum wavelength on the sea surface. 7. It is moored on the sea surface and has a horizontally elongated shape with a horizontal top surface and a circular bottom surface that changes from a small radius of curvature at the rear to a large radius of curvature at the front (pigeon chest shape) or is effective against waves due to the action of an underwater inertial body. A floating body that causes a pitching motion,
It consists of two air chambers located at the front and rear of the floating body, a horizontal duct that communicates with the lower part of the front and rear air chambers via each curved part, and an upper air passage that communicates between the upper surfaces of the front and rear air chambers. , Water is sealed in the horizontal duct so that the water column is located at the center of both air chambers, and a power generation device consisting of an air turbine and a generator is installed in the upper air passage to utilize the large pitching motion caused by the floating body due to waves. A high-performance wave power generation buoy characterized by converting the air output of the air chamber into electricity. 8. A high-performance wave power generation buoy, characterized in that the lateral length of the floating body according to claim 7 is about 0.04 to 0.06 times the maximum wavelength on the sea surface. 9. In the high-performance wave power generation according to claims 7 and 8, by arranging two air chambers in front and back adjacent to the oblong floating body, the wave direction of the device including the horizontal duct is improved. A high-performance wave power generation buoy characterized by its short length. 10. In the high-performance wave power generation buoy as set forth in claim 9, the lower air chambers arranged in the front and back adjacent to the oblong floating body are horizontal air chambers connecting two air chambers with an open bottom or side surface. A high-performance wave power generation buoy characterized by the omission of ducts.