JPS6129981Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a floating wave power generation device that doubles as a floating breakwater and is attached to an object floating on a wave surface to efficiently absorb the energy of incident waves and convert it into electrical energy. It is something.

As shown in Figure 1, in the conventional wave power generation device, a funnel-shaped structure A is installed upside down on a quay 8, and as the water level inside the funnel rises and falls as waves approach it, the water level rises and falls from the top of the funnel. Air enters and exits, the air flow drives an air turbine 4, and a generator 5 generates electricity.

In this wave power generation device, the bottom end B of the funnel must be sufficiently submerged under the water surface in order to prevent the bottom surface of the funnel from being exposed above the water surface. Therefore, the amplitude of the rise and fall of the water surface in the funnel is the same as the point B of the incident wave. This is supported by the amplitude of the subsurf S at , and is considered to be considerably smaller than the amplitude of the incident wave. For example, if we consider a case where a sinusoidal two-dimensional wave is occurring on the surface of a deep ocean, a plane located at a depth Z below the water surface in the absence of waves has an amplitude exp.
A sinusoidal wavefront is formed such that (-2xZ/λ) (λ=wavelength). This wavefront is called subsurf S. The amplitude of subsurf S becomes smaller as Z becomes larger, that is, as the depth increases.

Furthermore, since the lower end B of the funnel must be sufficiently submerged under the water surface, the funnel will be subject to large fluctuating pressure near the water surface, which is extremely disadvantageous in terms of structural strength.

In order to overcome the drawbacks of conventional wave power generation devices as mentioned above, the present inventor first applied for
An improvement plan was proposed in No. 111614 (Utility Model Application No. 51-39143). What is shown in FIG. 2 is one embodiment of the improvement plan.

In Fig. 2, the shallow floating body 1 of the water is
It is installed so that it can rotate around the center. The air push plate 6 has a rigid body and is partially engaged with the floating body 1, and is configured to rotate around the support shaft 2 like the floating body 1, and has the role of pushing the air pump 3. . The air dust 7 guides the airflow from the air pump 3 to the air turbine 4, drives the generator 5, and generates electricity. The chain 9 connecting the floating body 1 and the quay 8 serves to suppress the displacement of the floating body 1 due to wave motion to below a certain limit, and to prevent the air pump 3 from being destroyed.

When waves occur on the water surface, the floating body 1 makes a reciprocating motion about the support shaft 2, pushes the air pump 3, and sends out a reciprocating airflow to the air duct 7. The reciprocating airflow thus created is sent to the air turbine 4, which drives the generator 5 to generate electricity.

The wave power generation devices illustrated in FIGS. 1 and 2 described above are both directly attached to a coast or a large floating structure. Therefore, in order to install the wave power generation device, there are restrictions such as the condition of the coast, and it has been impossible to apply it to all coasts. Furthermore, it has been extremely difficult to obtain a highly efficient floating wave power generation device.

Regarding wave-dissipating devices, in order to keep the water surface within a harbor calm, breakwaters are used to block waves from the open sea. However, although the currently commonly constructed breakwaters can block waves from the open sea and keep the bay calm, they also limit the exchange of water within the bay with clean water from the open sea. The water quality is contaminated and is not suitable for industrial use, nor is it sanitary. Also, oyster farming,
It will also have a negative impact on the fisheries industry, such as seaweed cultivation and fish farming. The energy of waves is concentrated near the water surface, and the concentration tendency is small in the flow velocity distribution of tidal currents, etc., so if a wave dissipating device that floats on the water surface and has high wave dissipation efficiency can be manufactured, the water inside and outside the wave dissipating device will be absorbed. It passes freely in and out of the bay, eliminating almost any risk of deteriorating the water quality in the bay.

The purpose of the present invention is to eliminate the drawbacks of the conventional example described above, and the purpose is to create a pair of floating bodies that is sufficiently long compared to the wavelength λ of the incident wave, and to set the center-to-center distance between the floating bodies to S.
When λ/S=1.4 to 2.5, an inverted funnel-shaped member with a wide opening submerged in the sea is fixed between the floating bodies, and the inverted funnel-shaped member is placed on the floating body. An air turbine is installed at the narrow outlet of the member via a valve that regulates the reciprocating airflow into a one-way flow, and the floating body efficiently absorbs the energy of waves incident on the floating body. The present invention aims to provide a floating wave power generation device which has a wave-dissipating effect and which converts absorbed energy into electrical energy.

The novelty of this invention is that the wave power generation device is made into a floating body.In other words, the device is attached to an object floating on the wave surface, and the energy of the incident waves is efficiently absorbed and converted into electrical energy. This was done in such a way that it was possible to do so.

Furthermore, as described above, by efficiently absorbing the energy of the incident wave by the floating body, the energy of the transmitted wave is reduced, thereby providing a wave-dissipating effect.

Specifically, this method takes advantage of the fact that the relative motion between the twin hulls and the water surface of the twin hulls placed in a transverse wave becomes extremely large for a certain frequency.

Next, the basic idea of the present invention will be described.

When an incident wave hits some floating body, the energy of the incident wave is equal to the energy of the reflected and transmitted waves plus the energy absorbed at the floating body. Now, if the energy of the incident wave is efficiently absorbed by an efficient wave power generation device, the energy of the transmitted wave passing through the floating body will be reduced, and therefore the wave height of the transmitted wave will be: The wave height is significantly lower than that of the incident wave. In other words, an efficient wave power generation device in a floating state can serve as a floating breakwater with good wave dissipation efficiency.

FIG. 3 is a perspective view showing a situation in which the amplitude of the relative water level between the twin bodies is measured when a wave of a certain wavelength (λ) is incident on the twin bodies.

In FIG. 3, reference numeral 10 indicates a pair of elongated cylindrical floating bodies (hereinafter abbreviated as cylinders). The length of this cylinder is made long enough to handle phenomena related to incident waves two-dimensionally. 11 is a support plate fixed to the upper end of each cylinder, 12 is a support stand fixed to the support plate 11, and 13 is a pair of connecting members that connect the upper ends of the pair of cylinders in the front and back. A twin body is formed by the pair of cylinders 10, the support plate 11, the support base 12, and the connecting member 13. 14 is a pair of water level gauges attached to two locations on the connecting member 13, S is the distance between the centers of the cylinders 10, λ is the wavelength of the wave that enters the twin body from the direction of the white arrow, and W and L are stationary. Shows the horizontal plane of the state.

Figures 4 and 5 show water level gauges 1 installed at two locations between the cylinders 10 of the twin body shown in Figure 3.
4 is a chart showing the measured values of the amount of displacement of the water surface between the cylinders 10 with respect to the twin body when waves of various wavelengths λ are incident on the twin body, the so-called relative water level amplitude, together with theoretically calculated values. .

In these figures, the vertical axis is the relative water level amplitude H _R
It is a value obtained by dividing by the incident wave amplitude H _r to make it dimensionless, and the horizontal axis shows a dimensionless value obtained by dividing the incident wavelength λ by the center-to-center distance S between the cylinders 10. In addition, the 〇 marks are measured values, and the solid lines indicate theoretically calculated values.

Moreover, FIG. 6 shows the average of the values of the curves in FIGS. 4 and 5. According to Figure 6,
In the two regions of λ/S=0.7 to 1.1 and 1.4 to 2.5, the incident wave is amplified and the relative water level amplitude becomes larger than the incident wave amplitude. Among these, λ/S=0.7~1.1
In the short wavelength region of , even though the relative motion of the wavefront is large, the actual motion of the wavefront is as shown in Figure 7A, according to observation. On the other hand, λ/S=1.4~2.5
In the region of , the twin fuselage almost only moves up and down, and the water surface between the cylinders has a longer wavelength than the width of the water surface, so it moves up and down in almost the same phase as shown in Figure 7B. ing. That is, λ/S=1.4~
In the region of 2.5, the width of the water surface between the cylinders is narrow relative to the incident wavelength, so there are few irregularities (waves) on the water surface, and the water surface acts as if it were a single flat plate with respect to the twin fuselage, making the incident light on average It was observed that the vertical movement was about twice the wave vibration.

The present invention utilizes the above-mentioned phenomenon to provide a device that can efficiently generate wave power generation using a floating body and also has an efficient wave dissipation effect.

The present invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

8 and 9 show an embodiment of the invention. FIG. 8 is a front sectional view, and FIG. 9 is a perspective view seen from below.

The twin body C floats on the water surface by a pair of elongated cylinders 15 that are sufficiently long compared to the wavelength of the incident wave.
The deck 17 attached via the support columns 16 is set so that the distance S between the centers of the pair of columns 15 is 1/2.5 to 1/1.4 of the wavelength λ of the natural wave at the installation point.
It is fixed by. The deck 17 is provided with a space for attaching a funnel-shaped structure 18. These are light enough to allow the device of the invention to float on the sea surface.

The funnel-shaped structure 18 is fixed to the deck 17 with the opening 18a facing downward, and the upper end communicates with the air duct 19. The side plates of the opening 18a are welded to the outer plates of the pair of cylinders 15, and the plates forming the front and rear ends are attached almost vertically to the lower ends of the cylinders 15.

The air duct 19 is attached to one end of the funnel-shaped structure 18, and has a known valve structure 20 for changing the reciprocating airflow in one direction (for example, the reference numeral shown in FIG. 6 or 7 of Japanese Utility Model Application Publication No. 51-39143) 10) are provided. One end opening is directed toward the air turbine 21 .

The air turbine 21 is directed toward the opening of the air duct 19 and is rotated by the air flow of the air duct 19 . The air turbine 21 is also connected to a generator 22 .

FIG. 10 shows the state in which the device of the present invention is suspended on the sea surface.

In Fig. 10, from the right side of the twin fuselage C, the wavelength λ
When a wave of do.

Depending on the size of this vertically moving wave, the air within the funnel-shaped structure 18 flows upward or downward in the figure due to the piston action of the water surface. The air is
By the action of the valve mechanism 20, the air is constantly converted into a useful flow, which is ejected from the air duct 19, rotates the air turbine 21, and is converted into electrical energy by the generator 22.

Furthermore, as described above, much of the energy of the incident waves is converted into the energy of waves moving up and down in the seawater portion of the funnel-shaped structure 18, and that energy is ultimately converted into electrical energy. Therefore, the energy of the wave passing through the twin fuselage C, that is, the transmitted wave to the left in FIG. 10, becomes small, and a wave-dissipating effect is therefore obtained. If you think about it this way,
Since an efficient wave power generation device should be a good floating wave dissipating device, the device of the present invention can also be used as a floating wave dissipating device. In this case, since it is a floating type wave dissipating device, water inside and outside can freely enter and exit through the bottom of the wave dissipating device, and there is no risk of polluting the water quality in the bay.

Note that the incident wave is amplified even in the range of λ/S = 0.7 to 1.1, but in that case, as mentioned above, the wavefront moves as shown in Figure 7A.
There is almost no piston action on the air in the funnel-shaped structure 18 and therefore no action to rotate the air turbine.

As shown in FIG.
When the anchor 24 is placed near the coast via the anchor 24, the waves hitting the vessel are swells with a substantially constant wavelength unique to that location, so the design should be designed by selecting an appropriate twin-hull spacing according to that wavelength. is possible. Furthermore, in this case, the energy of the waves hitting the shore is smaller than the energy of the incident waves by the amount converted into electrical energy, so this device also has the effect of a floating wave dissipating device.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the configuration of a conventional wave power generation device, Figure 2 is a schematic diagram showing the configuration of a conventional example with an improvement plan, and Figure 3 is a diagram showing waves of various wavelengths incident on the twin fuselage. Figures 4 and 5 are perspective views showing the situation in which the relative water level amplitude between the twin hulls is measured. A chart showing the measured values of the amplitude of the relative water level between the cylinders together with the theoretically calculated values when a wave with a wavelength of
Figure 7 is a diagram showing the average of the values of the curves in Figure 7, Figure 7 is a diagram explaining the results of observing the movement of the wave front between cylinders, Figure 8 is a front sectional view of the device of the present invention, and Figure 9 is a diagram of the device of the present invention. FIG. 10 is a sectional view showing the device of the present invention floating on the sea surface, and FIG. 11 is a perspective view of the device of the present invention placed near the coast. 15...Cylinder, 16...Support column, 17...Deck, 18...Funnel-shaped structure, 18a...Opening, 19...Air duct, 20...Valve mechanism, 21
...Air turbine, 22...Generator, C...Twin fuselage.

Claims (1)

[Scope of utility model registration request] When a pair of floating bodies is sufficiently long compared to the wavelength λ of the incident wave, and the distance between the centers of the floating bodies is S, λ/
A reverse funnel-shaped member whose wide opening is submerged in the sea is fixed between the floating bodies, and the narrow outlet of the reverse funnel-shaped member is connected to the floating body in a relationship such that S = 1.4 to 2.5. A floating wave power generation device in which an air turbine is installed through a valve that regulates reciprocating airflow to one-way flow.