JP2018053802A - Wave power generation device and method for installing wave power generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wave power generation device that can be relatively easily installed without a reduction in generation efficiency, and to provide a method for installing the wave power generation device.SOLUTION: A wave power generation device 1 includes: a pillar 2 moored underwater in an erected state; a float 3 vertically moving with a wave along the pillar 2; and a power generation mechanism 4 for generating power using relative motion of the float 3 to the pillar 2. A hollow body 14 is installed to the pillar 2 and sea water is brought into a poured state by pouring the sea water into the hollow body 14 when the wave power generation device 1 is disposed underwater.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wave power generation apparatus that generates power using energy when a float moves up and down, and a method for installing the wave power generation apparatus, and more particularly, it is relatively easy to install without reducing power generation efficiency. The present invention relates to a wave power generator that can be used and a method for installing the wave power generator.

  Various wave power generators that generate power by the relative movement of a float with respect to a support column installed in water have been proposed (see, for example, Patent Document 1). In the wave power generation device described in Patent Document 1, a support is fixed to the seabed (pile driving method). This wave power generator could not be installed in a relatively deep sea area because the lower end of the support must be fixed by reaching the bottom of the sea.

  On the other hand, a method of tension mooring by connecting anchors and struts sunk in the seabed with mooring lines is also conceivable (tension mooring method). At this time, a buoyant body is installed on the support column. An upward force from the buoyant body and a downward force from the mooring line are generated in the column. By tensioning the mooring line, the column is fixed in the water. This configuration makes it possible to install a wave power generation device in a relatively deep sea area.

  However, in order to fix the column so that it does not move up and down due to the influence of waves, it is necessary to increase the size of the buoyant body installed on the column and increase the size of the anchor. When installing a wave power generation device, it is necessary to transport a large-sized anchor to a predetermined sea area, resulting in a problem that the transportation cost increases. In addition, a large crane or the like is required for the work when the anchor is submerged in the seabed, resulting in a problem that the installation cost increases.

  Moreover, the support | pillar fixed by the tension mooring system may move to the downward direction which becomes a direction approaching a water bottom with a tide level change. When the column moves downward, the mooring line is loosened, and the column is not fixed. At this time, since the column moves up and down in synchronization with the wave, the relative motion with the float becomes small, and the power generation efficiency decreases.

  As described above, the pile driving method has a problem that a wave power generation device cannot be installed in a deep water area. Further, the tension mooring method has a problem that the installation cost of the wave power generator increases and the power generation efficiency decreases due to a change in tide level.

JP 2007-518024 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a wave power generator and a wave power generator installation method that can be installed relatively easily without reducing power generation efficiency. It is.

In order to achieve the above object, a wave power generator according to the present invention comprises a column disposed underwater in a standing state, a float that moves up and down by waves along the column, and a relative relationship between the float and the column. A wave power generation apparatus including a power generation mechanism that generates electric power using motion includes a hollow body installed on the support column, and the hollow body is configured to be filled with seawater. .

  The installation method of the wave power generation device of the present invention utilizes a support column moored underwater in a standing state, a float that moves up and down by waves along the support column, and a relative motion between the float and the support column. In a control method of a wave power generation device including a power generation mechanism for generating power, the method includes a hollow body installed on the support column, and the hollow body is poured with seawater when the wave power generation device is disposed in water. It is characterized by water injection.

  According to the wave power generation device and the installation method of the wave power generation device of the present invention, the mass of the support can be increased by filling the hollow body with seawater, and the natural period of the support can be lengthened. . This makes it easier to fix the column to the wave.

It is explanatory drawing which illustrates the wave power generator of this invention. It is explanatory drawing which illustrates the float of FIG. 1 in a cross section. It is explanatory drawing which illustrates the modification of the hollow body of FIG. It is explanatory drawing which illustrates another modification of the hollow body of FIG. It is explanatory drawing which illustrates the water injection state of the hollow body of FIG. 4 in a cross section. It is explanatory drawing which illustrates the empty state of the hollow body of FIG. 5 in a cross section.

  Hereinafter, a wave power generation device and a wave power generation device installation method according to the present invention will be described based on the embodiments shown in the drawings.

  As illustrated in FIG. 1, a wave power generator 1 according to the present invention includes a support column 2 that is placed underwater in a standing state, a float 3 that moves up and down by waves along the support column 2, and the float 3 and the support column. And a power generation mechanism 4 that generates power using relative motion with the power generation mechanism 2.

  The support column 2 is formed in, for example, a cylindrical shape having an up-down direction as an axial direction, and is disposed in the water in a state in which a part of the upper part protrudes on the water and the remaining part is submerged in the water. The shape of the support column 2 is not limited to a cylindrical shape, and may be a prism shape in which a cross section in a direction parallel to the horizontal plane is a quadrangle or a polygon.

  One end of a mooring line 5 composed of a wire, a rope, or the like is connected to the lower end of the column 2. The other end of the mooring line 5 is connected to an anchor 7 disposed on the bottom 6.

  You may make it the structure which installs in the lower end part of the support | pillar 2 the flat plate-shaped heave plate 8 extended in a horizontal direction. Since the heave plate 8 serves as a resistance when the support column 2 moves up and down in synchronization with the wave, the natural period of the support column 2 can be increased. In the present invention, the heave plate 8 is not an essential requirement.

  The float 3 is formed in a cylindrical shape having a through hole 9 through which the support column 2 penetrates at a substantially central portion in plan view. The shape of the float 3 is not limited to the above, and it is sufficient that the float 3 has a shape that moves up and down by waves along the support column 2. For example, the float 3 may be formed in a spherical shape or a rectangular tube shape.

As illustrated in FIG. 2, the power generation mechanism 4 includes an annular core 10 disposed inside the float 3 and surrounding the outer peripheral surface of the support column 2, a coil 11 wound around the core 10, and a coil 11. And a battery 12 to be connected. The power generation mechanism 4 includes a permanent magnet 13 installed on the support 2.

  When the float 3 moves up and down relatively with respect to the support 2, the power generation mechanism 4 can generate power by electromagnetic induction. The configuration of the power generation mechanism 4 is not limited to the above, and any configuration may be used as long as it generates power using the vertical movement of the float 3 with respect to the support 2. For example, the power generation mechanism 4 may be configured by a motor installed on the float 3, a pinion gear installed on the motor, and a rack installed on the support column 2 and extending in the vertical direction. The pinion gear arranged on the float 3 side is configured to mesh with the rack and rotates by the vertical movement of the float 3.

  Electricity generated by the power generation mechanism 4 is supplied to the outside of the wave power generation device 1 via the battery 12. The battery 12 may not be installed and electricity may be directly supplied to the outside from the power generation mechanism 4.

  As illustrated in FIG. 1, a hollow body 14 is installed at the lower end of the column 2. The hollow body 14 is formed in, for example, a spindle shape, a spherical shape, or a cylindrical shape, and has a cavity inside. The hollow body 14 can be constituted by a rubber bag, for example, and may use a fender. The hollow body 14 should just have the structure which can pour at least seawater not only in the above. For example, the hollow body 14 may be made of plastic. On the outer peripheral surface of the hollow body 14, a valve 15 used for pouring seawater is disposed.

  When the heave plate 8 is installed in the wave power generation device 1, the hollow body 14 may be installed at the lower end of the heave plate 8.

  Next, the installation method of the wave power generator 1 of this invention is demonstrated. When the wave power generation device 1 is transported on a work boat or the like, it is desirable that the interior of the hollow body 14 be empty. When the hollow body 14 is formed of a relatively soft material such as rubber, the empty hollow body 14 can be folded and transported. This is advantageous for reducing transportation costs.

  After the work ship arrives at a predetermined sea area, the wave power generator 1 is moved underwater from the work ship by a crane or the like installed on the work ship. At this time, the anchor 7 connected to the column 2 via the mooring line 5 is thrown into the water. In this embodiment, the mooring line 5 is set to a length that can maintain a relaxed state even when the anchor 7 is landed on the seabed.

  After the wave power generation device 1 is placed in the water, water around the work ship is injected into the hollow body 14 connected to the lower end of the support column 2 using, for example, a pump installed on the work ship. To do. Seawater is injected into the hollow body 14 via the valve 15 and enters a water injection state.

  The water-filled hollow body 14 is desirably adjusted to a neutral buoyancy state in which the mass of the hollow body 14 and the buoyancy acting on the hollow body 14 are equal. In this specification, the neutral buoyancy state is a state in which the weight of the hollow body 14 in water is zero, and when the hollow body 14 is disposed at an arbitrary position in water, the state in which the hollow body 14 does not float or sink. Say. The neutral buoyancy state includes not only a state in which the mass and buoyancy of the hollow body 14 are strictly equal, but also a state in which the mass has an error of about ± 10% with respect to the buoyancy of the hollow body 14 in the water injection state.

  For example, when the buoyancy acting on the hollow body 14 is 100 kg, a neutral buoyancy state is assumed if the mass of the hollow body 14 in a water-filled state is in the range of 90 to 110 kg. Adjustment of the mass and buoyancy of the hollow body 14 can be performed by adjusting the amount of seawater injected into the hollow body 14.

  If the mass of the hollow body 14 itself is almost negligible with respect to the total mass of the hollow body 14 in the water-filled state, the hollow body 14 is almost in a neutral buoyancy state when the hollow body 14 is filled with water. Therefore, adjustment becomes easy.

Next, a description will be given of an increase in the natural period of the column 2 due to the installation of the hollow body 14. First, the natural period T (sec) of the floating body such as the support 2 can be expressed by the following formula (1) from the mass M (kg) of the floating body, the additional mass coefficient α, and the restoring force k (N / m). Here, the additional mass coefficient α refers to the proportion of mass that apparently increases due to the effect of acceleration in the surrounding seawater when the support column 2 or the like moves up and down in water.

Assuming that the support column 2 is cylindrical, the restoring force applied to the support column 2 (buoyancy minus weight) works as a spring force. The spring constant k representing the spring force can be expressed by the following formula (2) when the cylindrical cross-sectional area S is used.

Here, ρ represents the density of seawater (1000 kg / m 3), and g represents the acceleration of gravity (9.8 m / sec 2). Further, the mass M (kg) of the column 2 can be expressed by the following formula (3), where d (m) is a draft (submerged depth).

As described above, the equation (1) representing the natural period T of the support column 2 can be transformed into the following equation (4). In addition, when the support | pillar 2 is a cylindrical shape, it will be about additional mass coefficient (alpha) = 0.1.

  From the above equation (4), the natural period T is about 2.1 sec when the draft of the column 2 is 1 m, for example, T = about 4.2 sec when the draft is 4 m, and T = about 6.3 sec when the draft is 9 m. Become. Since the wave period constantly changes, for example, in 4 to 12 seconds, the column 2 that does not include the hollow body 14 moves up and down in synchronization with the wave.

  In the present invention, since the mass M of the column 2 in the formula (1) is increased by installing the hollow body 14, the natural period T of the column 2 can be lengthened. If the mass of the water-filled hollow body 14 is equal to or larger than the buoyancy generated in the hollow body 14, only the mass M increases without increasing the spring constant k of the formula (1). It can be increased efficiently.

  With the configuration in which the water-filled hollow body 14 is installed on the support column 2, the natural period T of the support column 2 can be increased to, for example, 20 sec. Since the natural period T = 20 sec of the support column 2 is sufficiently larger than the wave period of 4 to 12 sec, the support column 2 hardly moves up and down in synchronization with the wave. Since the support column 2 is almost stopped in the water with respect to the float 3 that moves up and down in synchronization with the waves, the relative motion in the vertical direction between the support column 2 and the float 3 becomes relatively large, and power generation efficiency is maintained. Can do.

  Since the support column 2 is almost stopped in the water, the wave power generator 1 can be installed by a loose mooring method in which the support column 2 is moored with the mooring cable 5 loosened. Since the anchor 7 used in the loose mooring method only needs to prevent the wave power generation device 1 from flowing from a predetermined sea area, the anchor 7 can be reduced in size. By reducing the size of the anchor 7, the installation cost and the transportation cost of the anchor 7 can be suppressed.

  Since the wave power generator 1 can be moored by a loose mooring method in which the mooring line 5 is loosened, there is no possibility that the power generation efficiency of the wave power generator 1 is lowered even when the tide level changes.

  In the present invention, the anchor 7 is not an essential requirement. A state in which the support 2 is towed by being connected to a ship or the like with a wire or the like without installing the anchor 7 may be used. Since the support column 2 can be substantially fixed in water without using the anchor 7, the wave power generator 1 can efficiently generate power even in a state without the anchor 7.

  If the hollow body 14 is emptied when the wave power generation device 1 is transported, the weight of the wave power generation device 1 hardly increases, so even if the hollow body 14 is installed, the transportation cost of the wave power generation device 1 is reduced. Increase can be suppressed. Even if the hollow body 14 is transported in a water-filled state, the effect of increasing the natural period T of the support column 2 and suppressing the installation cost can be obtained. The configuration to be performed is not an essential requirement of the present invention.

If the hollow body 14 in the water injection state is drained, the wave power generation device 1 can be easily recovered and transported. For example, the wave power generation device 1 is transported by a work ship and poured into water at a predetermined position, and water is poured into the hollow body 14 to start power generation. Electricity generated by the wave power generator 1 is supplied to a diver's luminaire or the like to support the diver's underwater work. After completion of the work, the wave power generator 1 can be drained from the hollow body 14 and collected in a work ship and returned to the port or the like. That is, the wave power generator 1 can be used as a portable generator.

  You may make it the structure which conveys the hollow body 14 in the state isolate | separated from the wave power generator 1, and connects the hollow body 14 to the support | pillar 2 in a predetermined sea area. Moreover, you may make it the structure which tow and convey the wave power generator 1 of the state which floated in the water with a work ship. When towing the wave power generation device 1 on a work ship, an empty hollow body 14 may be installed in the support column 2 in advance, or a water-filled hollow body 14 may be installed in the support column 2 in advance. Good.

  As illustrated in FIG. 3, a plurality of hollow bodies 14 may be installed on the column 2. In this embodiment, the hollow body 14 is formed in a spherical shape, and is arranged side by side in the horizontal direction. The plurality of hollow bodies 14 are arranged side by side on the circumference surrounding the support 2.

  With the configuration in which a plurality of hollow bodies 14 are arranged in the horizontal direction, when the support column 2 tries to move up and down by waves, the hollow body 14 becomes the resistance. That is, the hollow body 14 exhibits the same effect as the heave plate 8 of FIG. It is advantageous to suppress the support 2 from moving up and down in synchronization with the wave.

  As illustrated in FIG. 3, a plurality of mooring lines 5 and anchors 7 may be installed in the wave power generation device 1. The configuration in which the plurality of anchors 7 are installed makes it difficult for the wave power generator 1 to flow from a predetermined sea area. It is advantageous to further reduce the size of the anchor 7 per one.

  As illustrated in FIG. 4, the strut 2 of the wave power generation device 1 and the work ship 16 may be connected by a towline 17 to prevent the wave power generation device 1 from flowing from a predetermined sea area. . The towline 17 is composed of, for example, a wire or a rope. In this embodiment, the wave power generation device 1 does not include the mooring line 5 and the anchor 7.

  The structure in which the hollow body 14 in a water injection state is installed on the support column 2 makes it difficult for the support column 2 to move up and down by waves. Therefore, the wave power generation device 1 can efficiently generate power even when connected to the work ship 16 by the towline 17.

  The hollow body 14 of this embodiment is configured in an annular shape that covers the periphery of the lower end portion of the column 2. Since the hollow body 14 is fixed to the support 2, the hollow body 14 becomes the resistance when the support 2 attempts to move up and down in synchronization with the wave. Since the hollow body 14 produces the same effect as the heave plate 8, the column 2 can be easily fixed in water.

  The hollow body 14 can be made of a material that is easily deformed, such as rubber. Therefore, as illustrated in FIG. 5, the hollow body 14 swells in a water injection state in which seawater is poured into the hollow body 14. As illustrated in FIG. 6, when seawater is drained from the inside of the hollow body 14 to make it empty, the hollow body 14 is deflated. If the hollow body 14 is in an empty state, even if the wave power generation device 1 is towed and transported by the work ship 16, the volume of the hollow body 14 becomes small, so that it can be easily transported.

DESCRIPTION OF SYMBOLS 1 Wave power generator 2 Support | pillar 3 Float 4 Power generation mechanism 5 Mooring line 6 Water bottom 7 Anchor 8 Heave plate 9 Through-hole 10 Core 11 Coil 12 Battery 13 Permanent magnet 14 Hollow body 15 Valve 16 Work ship 17 Towing

Claims (8)

In a wave power generation device comprising: a support column disposed underwater in a standing state; a float that moves up and down by waves along the support column; and a power generation mechanism that generates electric power using relative motion between the float and the support column. ,
A wave power generation device comprising a hollow body installed on the support column, the hollow body configured to be filled with seawater.   The wave power generation device according to claim 1, wherein the hollow body is configured to be switchable between an empty state in which the interior is empty and a water injection state in which seawater is filled inside.   The seawater is filled in the hollow body in a state where the mass of the hollow body is the same or larger than the buoyancy acting on the hollow body in a state where the entire body is submerged. The wave power generator described in 1.   The wave power generation device according to any one of claims 1 to 3, wherein the hollow body is formed of a rubber bag.   The wave power generation device according to any one of claims 1 to 4, comprising a plurality of the hollow bodies, wherein the plurality of the hollow bodies are arranged in a horizontal direction. A wave power generation apparatus comprising: a support column moored underwater in a standing state; a float that moves up and down by waves along the support column; and a power generation mechanism that generates electric power using relative motion between the float and the support column. In the installation method,
It has a hollow body installed on the column,
An installation method for a wave power generation device, wherein when the wave power generation device is placed in water, the hollow body is poured with seawater.   The wave power generator installation method according to claim 6, wherein when the wave power generator is transported, the hollow body is in an empty state in which seawater is drained from the inside.   When the hollow body is in the water injection state, the amount of seawater injected into the state where the mass of the hollow body is the same or larger than the size of the buoyancy acting on the hollow body in a state where the whole body is submerged. The installation method of the wave power generator of Claim 6 or Claim 7 with which is adjusted.

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