Underwater facility for increasing flow rate of tidal current and use thereof

Abstract

To provide an underwater facility for increasing a flow rate of tidal currents in a predetermined sea area at a predetermined water depth in the sea, which flow in laminar manner in one direction.SOLUTION: Along each of right and left side surfaces of a predetermined sea area having a right-left width L0, a plurality of plate-shaped underwater vertical floats KF with a narrow right-left width t and a depth difference h, and with a dimension p extending in a flow velocity direction, are provided in an upstream direction; the right and left underwater vertical floats KF widen their interval in a V-shape along the upstream side to form an induction water channel that increases a flow velocity; and each underwater vertical float is moored to a large sea surface float SF and a seabed anchor AN with a number of wires W in the front-back, right-left, top-bottom directions to hold it approximately vertically in the sea.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] This invention is an underwater facility that can increase the speed of a tidal current in a specific area of ​​the ocean where there is a tidal current, and as a method of using this facility, if a tidal power generation device is installed in a specific section of this area, the output can be increased significantly. Or, by providing an area of ​​a fast current for fish living in the ocean, the amount of movement of the fish can be increased, making it possible to cultivate fish in a fish cage in a state close to nature. Also, this invention relates to other applications of underwater facilities that can utilize fast tidal currents. [Background technology]

[0002] Natural disasters caused by global climate change are becoming increasingly severe, and people are beginning to fear for the very survival of humanity on Earth. COP26 warns that unless CO2 emissions, the main cause of global warming, are reduced to zero by 2050, the Earth will become uninhabitable. The world is making desperate efforts to reduce CO2 emissions, but the results so far have been insufficient, and pessimistic predictions are beginning to emerge. For example, in land-based industries, the use of coal-fired power plants has stalled due to the economic reality, in renewable energy, solar power generation and wind power generation, the main sources of power generation, have suffered significant output shortages due to bad weather, and in marine energy, technological development has stalled due to technical and cost difficulties. In ocean current power generation, the distribution of energy resources in the world is nearly infinite, but there are many technical challenges, such as deep seas, deep oceans, and variable movement. In tidal power generation, the distribution of energy resources is small, and the areas with high-speed currents required for power generation are limited. Many existing tidal power generation devices are installed on the seabed, but the possibility of installing the device depends on the shape of the seabed, which further limits the sea surface where it can be installed. In terms of the type of equipment, most cases are of the horizontal axis propeller type, which is derived from the propeller wheels of onshore wind power generation, but because the density of water is 800 times that of air, there are limitations in terms of strength and installation when making the blades longer, and therefore it is said that there is a limit to the output of a single unit. The largest example currently available is about 200mD x 2MW of wind power. This once again highlights the technical and cost difficulties involved in tidal power generation.

[0003] A technique for increasing the movement of fish and improving the environment in a fish pen by generating a high flow rate of seawater in the pen using a pump is known. However, there are known facilities that improve the environment of a fish cage by operating a pump to generate a seawater current or by providing a rotor that rotates inside the cage with a rotating device.

[0004] However, in order to operate the pump or rotate the rotating device, the engine must be operated using electrical energy or fuel. This requires the use of electricity or the cost of engine fuel. There is a problem in that the electricity and fuel costs become high when used for a long time.

[0005] In addition, as a method of doubling the flow velocity in a part of the water body in seawater, rivers or water pipes, if the water channel area is reduced, the flow velocity through the small water channel area will increase, which is a well-known technique known as Bernoulli's theorem. Structures for increasing the flow velocity in land water channels can be easily manufactured and constructed using concrete blocks, or plastic or steel water channels. However, in order to increase the flow speed of seawater, it is possible to build a diversion channel that gradually reduces the flow area of ​​the seawater in a specified sea area by constructing a waterway embankment (waterway wall) out of strong materials such as concrete blocks or steel products. However, constructing such a large-scale waterway embankment in the sea requires large-scale seabed construction work, which poses the problem of high construction costs due to the costs of manufacturing and transporting the waterway embankment blocks as well as large-scale seabed construction work to install them on the seabed.

[0006] In particular, with tidal power generation, the distribution of tidal energy resources is small worldwide, and the areas with the high-velocity currents required for power generation are limited. Furthermore, existing tidal power generation devices are installed on the seabed, so they are dependent on the shape of the seabed, further limiting the sea surface where they can be installed. Tidal currents are said to be generated by the movement of seawater on the ocean surface due to the gravitational forces of the Earth, Moon and Sun. Among these, high-velocity tidal currents are understood to be the result of tidal currents being accelerated by narrow waterways and straits created accidentally by natural land coasts. In reality, there are not many places where they occur, and the world's energy resources are also small. Therefore, the contribution of tidal power generation to green electricity worldwide is small and limited, and investment is also sluggish. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2012-2220 A [Patent Document 2] Patent No. 4717966 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention provides underwater equipment that uses the flow velocity of natural tidal currents to increase their speed in a specific sea area, thereby improving the fish cage environment in the specific sea area by using the increased speed tidal current as is, or using the increased speed tidal current to operate underwater tidal power generation equipment to generate tidal power and produce high output electricity at low cost, and the generated energy can be supplied to onshore or offshore equipment via an undersea electric cable, or the generated energy can be used to produce hydrogen fuel at low cost and supply hydrogen as a fuel source to onshore equipment, offshore ships and underwater aquaculture equipment, or even by generating electricity underwater and using that electricity or hydrogen as an energy source for underwater fish cages and aquaculture equipment, it is possible to operate fish cages and aquaculture at low cost, reduce energy costs in the fishing industry and improve the marine ecological environment of the fish in the sea area, as well as technology for using such underwater equipment, such as tidal power generation devices and underwater aquaculture equipment.

[0009] The present invention aims to provide underwater equipment for increasing the flow velocity of tidal currents below the sea surface in a specified area of ​​the tidal current, and to provide a technology for using the equipment, which can increase the flow velocity of the tidal current at low construction costs. In particular, by installing a tidal power generation facility in a specific area of ​​the sea, a large amount of power generation energy can be output even in the sea with a slow natural tidal current, enabling the supply of cheap electricity, and hydrogen can be produced in the sea as a large amount of energy source at low cost using the generated energy, making it possible to provide hydrogen as an energy source on land at low cost, and furthermore making it easy to use the facility as energy for underwater fish cages and aquaculture facilities. [Means for solving the problem]

[0010] The configuration of the present invention that solves such problems is as follows: 1) In a tidal area where natural tidal currents occur at a specified depth below the sea surface and the flow velocity is a laminar flow in approximately the same direction, A submarine facility for increasing the flow velocity of a tidal current in a specified sea area, the submarine facility having a predetermined width L0 in a direction perpendicular to the flow velocity direction of the natural tidal current and approximately parallel to the seabed surface, a length p in the upstream direction of the tidal current from each of the left and right ends of the predetermined width L0, and a cube with three sides of lengths L0 x p x d, the length p being determined by a required depth difference d at the specified water depth, A plate-shaped subsea vertical float having a required length p and a required left-right thickness t, and a size of p×h×t, is arranged along the left and right sides of the cube of the specified sea area from the left and right end positions separated by the specified width L0, along the upstream of the natural tidal current, and the subsea vertical float is connected by wires to a large surface float floating on the sea surface above it to give it a large buoyancy upward, and is connected by wires to a plurality of seabed anchors installed on the seabed surface below it to keep the subsea vertical float approximately vertical at a specified position in the sea. and further, a plurality of submarine vertical floats having the same structure and approximately the same dimensions t and h are arranged in a row in the upstream direction of the tidal current so that their leading and trailing ends are in contact with or continuous with each other at the upstream tip of the submarine vertical float. The submarine vertical floats are arranged so that the left and right spacing between the submarine vertical floats arranged opposite each other widens the further up the tidal current they go, and the left and right spacing between the submarine vertical floats expands in a V-shape. Each submarine vertical float is moored with a plurality of wires to a large surface float floating above, and also moored with a plurality of wires to a seabed anchor below so that it can be left stationary. A wire connects each row of submarine vertical floats between the front and rear of the submarine vertical floats and between pairs of left and right submarine vertical floats, and each submarine vertical float is further moored to a plurality of seabed anchors installed on the left, right, front and rear of the float with wires extending in the left and right, front and rear, and up and down directions, so that the submarine vertical floats arranged in a V-shape in the direction of the tidal current can be moored and held in a V-shape, and the double row of V-shaped submarine vertical floats forms an underwater waterway that guides the tidal current in a specified sea area, and the underwater waterway formed by the V-shaped submarine vertical floats narrows the passage area of ​​the left and right submarine waterways, thereby accelerating the tidal current and resulting in a high tidal current speed in the specified sea area. 2) The underwater vertical wall float has an outer shell made of steel plate or strong metal and shaped into a vertical box with a short width, and the outer shell is filled with foamed resin at a predetermined ratio to form a nearly vertical float. The outer surface of the underwater vertical wall float is hard to break and has a buoyancy. This is the underwater equipment for increasing the flow speed of a tidal current described in 1) above. 3) In the underwater facility for increasing the flow speed of a tidal current described in 1) or 2), a tidal current power generation device that generates electricity from tidal current energy is installed in a specified sea area downstream of where the flow speed of the tidal current has increased, thereby enabling high electrical output even at high tidal current speeds. is located. Effect of the Invention

[0011] According to the present invention, in a sea area of ​​a specific depth where the tidal current flows in a vertical laminar current with the direction being approximately the same, submarine vertical floats are arranged on the left and right of the specific sea area in a V-shape with the left and right distances increasing toward the upstream direction of the tidal current. Each of these submarine vertical floats is moored by a wire to a large float floating on the sea surface, exerting a large buoyancy in the upward direction. To counter this large buoyancy, multiple seabed anchors are provided on the seabed below the submarine vertical float, and the submarine vertical float is moored to the seabed anchors by multiple wires, generating a pulling force downward toward the seabed, thereby countering the buoyancy and holding the submarine vertical float at a specific position in the sea. The submarine vertical floats arranged in a row can basically be held as a waterway that guides the tidal current in the seawater to a specific sea area at a specific depth. Furthermore, the submarine vertical floats in a row are connected to each other with wires at the front-to-back and left-to-right intervals, and seabed anchors are installed widely at the front-to-back, bottom, left-to-right intervals, and these are moored to the submarine vertical floats with multiple wires, allowing them to be held firmly in the sea.

[0012] As a result, the natural tidal current is captured in the underwater channel of the V-shaped row of submarine vertical floats, and is guided into the underwater channels of the left and right submarine vertical floats to a specific sea area with a small channel passage area. As a result, the natural tidal current flows from the tidal current induction port, which has a large channel passage area, to the specific sea area with a small passage area. Therefore, the flow speed of the tidal current in the specific sea area becomes much faster. The flow speed in this specific sea area can be two to three times faster than the natural tidal current speed, which can significantly increase the flow speed in that specific sea area.

[0013] Therefore, if a tidal power generation device is placed in this specific sea area, it will be possible to generate a large amount of electricity. Also, if it is made part of the swimming path of an aquaculture cage, it will be possible to stimulate the movement of the fish. The tidal power generation device may be a buoyancy flap rotation type tidal power generator developed by the applicant, a propeller type or a rotary water wheel type generator, or a power generator that is not a generator.

[0014] In sea areas where natural tidal currents exist, sea areas with high current speeds of 3 to 6 to 9 knots required for high-output power generation are limited and very rare. Therefore, as a solution to this problem, the present invention does not seek out sea areas with natural fast currents, but rather proposes that if slow currents can be artificially increased to high speeds, sea areas with the tidal current speeds required for power generation can be widely obtained. The speed of a slow current of 1 to 2 to 3 knots can be increased to a high current of 3 to 6 to 9 knots in a specific sea area. This makes it possible to realize high-output tidal power generation by the tidal power generation equipment using the buoyancy flap developed by the present inventor in sea areas with low current speeds. Even in limited areas of ocean with natural high-speed currents, it is even rarer to find a place where the shape of the seabed is suitable for installing the device. Moreover, by installing a buoyancy flap turbine type tidal power generation device, which is known from Patent Publication No. 5451938, developed by the present inventor, which allows the device to be installed underwater in an area of ​​a specified depth rather than on the seabed, it is easier to obtain a high-speed tidal current. This is because when the flow speed of the tidal current is close to the seabed or ocean surface, it becomes difficult to obtain a high-speed laminar flow because it is affected by the flow speed of the seabed or ocean surface, where there is no flow speed. This invention makes it easier to obtain a high-speed laminar flow by utilizing a laminar flow at an appropriate depth.

[0015] The installation of the subsea vertical wall float in the sea is performed by fixing one end to the subsea vertical wall float and pulling the other end upwards with a large sea surface float with a large buoyancy. On the other hand, by mooring the subsea vertical float to a seabed anchor and mooring it with multiple wires in the seabed direction, left-right direction, and front-back direction vertically downward, the subsea vertical wall float can be moored almost vertically in the sea by pulling it strongly up and down with the large buoyancy and the anchoring force of the seabed anchor. In other words, the subsea vertical wall float is easily oriented in an almost vertical direction in the sea due to the large vertical buoyancy toward the sea surface. Furthermore, the tension of multiple other mooring wires in the seabed surface direction, left-right direction, front-back direction, and diagonal direction, which are fixed at one end to the subsea vertical float, and the connecting force of the wires connecting the subsea vertical floats to each other, strongly holds the subsea vertical position in the sea against the forces of the tidal currents in the front-back and left-right directions that the subsea vertical float receives.

[0016] According to the present invention, the subsea vertical wall floats are installed so that the tips of a pair of subsea vertical float rows arranged on the left and right sides of a position KP0 at a predetermined distance L0 in a specific sea area of ​​a predetermined water depth where the underwater tidal current flows in a laminar flow in a fixed direction are at positions KP1, KP2, KP3... where the width gradually widens in a V-shape upstream. The installation is such that the tips of the elongated plate-like subsea vertical floats arranged on the left and right sides of the V-shape in a row are at a height of a predetermined water depth h at the predetermined water depth and with a width that widens upstream on the left and right sides, and the tidal current enters from the inlet that widens like a V-shape and flows in a streamline that narrows in width toward the specific sea area downstream. When an ocean current enters between the tips of the long floats at the upstream tips of this pair of left and right submarine vertical wall floats, which have a width of L1, at a flow velocity V0, the waterway narrows to a distance L0 on the left and right toward the specific sea area KPo, and the flow velocity V0 of the invading current increases in accordance with Bernoulli's theorem as it passes through the specific section KP0. As a result, the tidal current velocity at the tip KP0 of this specific sea area is increased to a current velocity V0 of about 1.5 to 3.0 times the current velocity V0 at the tip of the row of submerged vertical floats. K If a tidal power generation device is placed in this specific sea area, it will be possible to generate 2 to 9 times more electricity.

[0017] Furthermore, if this specific sea area is provided as a part of a fish cage, the cultured fish in the fish cage can be made to swim at high speed in this specific sea area, making it possible to culture fish that are firm and athletic.

[0018] Furthermore, although not explicitly shown in the drawing, if part of the tidal current downstream of the KP0 position in this specific sea area were to flow toward the seabed surface, the current would disturb the seabed, drawing out organic matter and small animals from the seabed mud and dispersing them into the current. This would release plankton, small fish, organic matter, and inorganic matter, which serve as food for fish, onto the current, making the downstream sea area seawater rich in food for fish, and also could cause fish to concentrate in this specific section downstream, increasing the catch downstream.

[0019] Moreover, in the present invention, each subsea vertical wall float is connected to the large surface float and the seabed anchor by multiple wires in the up-down, front-back, and left-right directions, so that it is stably held almost vertically at a specified water depth. The buoyancy of the large surface float makes it strongly vertical at a specified water depth, and the other ends of multiple wires fixed to the left and right subsea vertical wall floats, stretched downward, left-right, front-back or diagonally, are fixed to the seabed anchor to moor it almost vertically in the sea at a specified water depth, so that the shape of the subsea vertical wall float and the left-right and front-back positions of the mooring are not changed much. This prevents the gap between the left and right of the V-shaped subsea vertical wall float from expanding. The multiple wires fixed to the seabed anchor in the up-down, left-right and front-back directions counter the force that tries to deform and displace the shape and position of the subsea vertical wall float when hit by the tidal current, preventing the V-shape from collapsing, and allowing the speed increase in a specific section to be maintained. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a front view showing the installed state of a submarine vertical float according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram showing the planar arrangement of a pair of left and right submarine vertical floats that form the submarine waterway of the embodiment. [Diagram 3]FIG. 3 is an explanatory diagram showing a structure in which the submarine vertical float of the embodiment is fixed in the sea by a large surface float and a seabed anchor. [Figure 4] FIG. 4 is an explanatory diagram showing the injection and discharge of air or seawater into and from the submarine vertical float of the embodiment, and the control of the switching valve. [Diagram 5] FIG. 5 is an explanatory diagram showing the injection and discharge of air or seawater into and from the submarine vertical float of the embodiment, and the control of the switching valve. [Figure 6] FIG. 6 is an explanatory diagram showing the wire connection state on the upper surface of the submarine vertical float of the embodiment, the mooring wire fastener, and the air pressure supply and exhaust port. [Figure 7] FIG. 7 is an enlarged plan view showing a state in which a plurality of submarine vertical floats of the embodiment are arranged in a row. [Figure 8] FIG. 8 is an explanatory diagram showing a specific sea area of ​​the embodiment. [Figure 9] FIG. 9 is an explanatory diagram showing the structure of the submarine vertical float of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The submarine vertical wall float of the present invention is preferably made of a strong, rust-resistant metal plate as an outer shell, with a hard foamed resin with high strength and interconnected air holes inside, so that the air holes can be filled with either air or seawater alternately, and is preferably made of a structure and material that generates high buoyancy by air injection. Alternatively, it may be made of a structure and mechanism that allows air and seawater to be alternately fed into the space inside the hollow, vertical, narrow box-shaped metal shell. In this embodiment, either air or seawater can be pumped and discharged from the work ship SS on the sea surface to the submarine vertical float, and it has a control fluid line CF for switching the valve, an air / seawater discharge line FP, and a switching valve V.

[0022] The direction of the rotation axis of the rotor TH1 of the tidal power generation device TH of this embodiment is set so that it is approximately perpendicular to the direction of the maximum flow velocity in the sea / underwater where it is installed, and so that the direction of the tidal / water current and the pressure plate are approximately perpendicular at 90° of the rotation phase. In general, tidal / water currents are often approximately parallel to the seabed / water bottom, so the rotation axis of the rotor is often vertical, perpendicular to the ground surface of the seabed / water bottom where it is installed.

[0023] The hollow mounting base for the tidal power generation device in this embodiment comes in several types: a housing type in the shape of a cylinder, truncated cone or box that is fixedly installed on the seabed or water bottom; a subsea or underwater truss structure type that is fixed with anchors to the seabed or water bottom; a mounting base type that is suspended into the sea or water from an aerial structure above the sea or water surface (a bridge, underwater tower, etc.), or a mounting base type that is suspended into the sea or water from a floating body or ship hull that is moored above the sea or water surface.

[0024] The rotor of the tidal power generation device of this embodiment generally has a cylindrical outer shape that is rotatable relative to the installation base, but a rotor with a framework may also be used. A rotor that minimizes water resistance is selected.

[0025] The mounting frame of the buoyancy flap rotating tidal power generation device TH in this embodiment is a component that protrudes radially from the rotor blades TH1 in a roughly horizontal direction parallel to the installation ground. Because force is loaded onto this mounting frame from the pressure plate, the preferred structure for the mounting frame is one in which it is connected to a number of upper and lower horizontal frames each having one end attached to the rotor, and a number of vertical frames which connect the same upper and lower horizontal frames, minimizing water resistance to the rotation of the mounting frame and maintaining high strength.

[0026] The pressure plate of the rotating blades of the tidal power generation device TH of this embodiment uses scratch-resistant metal or plastic plates as the front and back surface materials, and is filled with foamed resin or honeycomb material inside, and the specific gravity of the entire pressure plate is slightly less than 1.0, preferably in the range of 0.95 to 0.99, relative to the specific gravity of seawater or underwater, which has a specific gravity of 1.00 to 1.05; if the specific gravity is too light, the buoyancy will increase, and the force that tends to horizontalize the pressure plate will be strong, slowing the descent of the free end and causing it to rise quickly, which is not preferable. Furthermore, the pressure plate may be a composite plate made of a plastic plate that is lighter than the specific gravity of seawater / water, 1.00 to 1.05, and a heavy metal / ceramic. Although not specifically described, the means for restraining the pressure plate of the rotor blades of the buoyancy flap rotating tidal power generation device TH of this embodiment is structured such that a lower stopper is provided at the lower end of the mounting frame to lock the free end of the pressure plate in an approximately vertical position, and an upper stopper is provided at the upper end of the mounting frame to prevent the pressure plate from rotating any further upwards when its free end is slightly lower than horizontal (4° or more) at an inclination angle (approximately 5°). As an alternative method for restraining the lower and upper stoppers, there is also a method of limiting the angle of rotation of the pressure plate at its pivot shaft. The detailed structure and operation of this tidal power generation device are disclosed in the applicant's Patent No. 5451938, so details will be omitted here. EXAMPLES

[0027] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 9 show an embodiment of the underwater facility of the present invention for increasing the flow speed of a tidal current, and are also embodiments of tidal current power generation facilities that are capable of outputting high power at the increased tidal current speed by installing the well-known buoyancy flap type tidal current power generation device in a specific sea area where the speed has been increased. The structure and operation of the tidal current power generation device are well-known and will not be described in detail, but as they are clearly stated in the above patent publication, details are omitted.

[0028] The present invention will be specifically described with reference to the embodiment shown in Figs. In this embodiment, as shown in Fig. 2, a natural tidal current flows in a substantially constant direction (upward in Fig. 2) under the sea surface as a laminar current, and a tidal current with a depth difference of a predetermined depth d flows in a constant direction in a laminar current. This is an example of an underwater waterway in which a V-shaped L0×p×h cubic submarine vertical float KF is arranged in a row to increase the flow speed of the specific sea area SA of L0×p×d in Fig. 2. The solid arrow at the bottom in Fig. 2 indicates the flow speed direction of the natural tidal current. In the figure, SA is the specific sea area of ​​L0×p×d cube. On the left and right sides of the specific sea area SA, narrow box-shaped submarine vertical floats KF of h×p×t with a left and right thickness t, height h≧d, and length p in the flow speed direction are arranged in parallel in the specific sea area SA, and further submarine vertical floats KF of the same structural dimensions are arranged in a row in front of and behind them so that the left and right intervals between them expand in a V-shape.

[0029] The subsea vertical floats KF are arranged in the plan view of Figure 2. Each subsea vertical float KF is connected to a large surface float SF floating on the sea surface by a wire W, and each subsea vertical float KF is connected to a seabed anchor AN by multiple wires W extending in the up-down, front-back, and left-right directions, and is moored in the sea.

[0030] The subsea vertical float KF is pulled upwards by the buoyancy of the large surface float SF, and is also connected and moored by multiple wires W to seafloor anchors AN arranged in the fore-aft, left-right, up-down and diagonal directions. In spite of the large buoyancy of the large surface float SF, the subsea vertical float KF is maintained in position at a specified depth underwater by the anchoring force of the seafloor anchors AN. Furthermore, each subsea vertical float KF is connected by wires between the front and back and between the left and right, and the subsea vertical float KF is maintained in a specified position in the sea by being moored by wires to many seafloor anchors AN arranged in the fore-aft and left-right directions.

[0031] As a result, by arranging the submarine vertical floats KF in a row, a guided waterway is formed that spreads out in a V-shape upstream with a depth difference h greater than the depth difference d at a specified water depth. Therefore, the natural tidal current entering from below in Figure 2 has its channel area narrowed by this guided waterway and flows into the specific sea area SA. In the specific sea area SA where the channel area is narrow, a high-speed laminar flow occurs due to Bernoulli's theorem. Therefore, the tidal power generation device TH installed in this specific sea area generates power from a fluid that is 2 to 3 times faster than the flow velocity V0 of the natural tidal current, and the amount of power generated by the tidal power generation device TH is 2 to 9 times greater than when it is placed in a natural tidal current.

[0032] Figure 1 is a front view of the induction waterway of this embodiment seen from the upstream side. In the center of the left and right are the specific sea area SA and the tidal power generation device TH. The submarine vertical floats arranged in a row are moored to a large surface float SF and a seabed anchor AN with a wire W, enabling the V-shaped shape of the submarine waterway to be maintained.

[0033] Figure 3 shows the approximately vertical state of each subsea vertical float KF, moored by a large surface float SF and a bottom anchor AN. Figures 4, 5, 6 and 7 show the air pump and seawater injection and discharge device, its air pipe, air pump, seawater injection and discharge line FP, control fluid line CF for the air passage and seawater feed pipe for air injection and discharge and seawater injection and discharge, and the control valve for the switching valve V on the work vessel SS floating on the sea surface. Air can be injected and discharged, and seawater can be injected and discharged from the work vessel SS on the sea surface, allowing adjustment of the buoyancy state. The amount of seawater and air in the subsea vertical float KF is adjusted to an appropriate level. Air can be injected and discharged from the work vessel SS using the sea surface air compressor, and this can be operated from the work vessel SS. [Industrial Applicability]

[0034] Although the present invention is primarily intended for generating electricity from tidal energy on the ocean floor, it can also be installed on the riverbed of a large river where there is a current to generate electricity. [Explanation of symbols]

[0035] K seafloor surface KF Subsea vertical float TH Tidal Power Generation Device TH1 rotor blade NF Natural Tides SA designated sea area SF Large sea surface float AN Subsea Anchor SS Workboat Left and right mooring positions of KP0, KP1, KP2, and KP3 subsea vertical floats YK Wire retaining part W Wire L0 Left and right width of designated sea area SA d Depth difference of the specified sea area SA p Length of a given sea area SA in the tidal direction h Height of the subsea vertical float t Thickness of the submerged vertical float KF V Switching Valve CF Control Fluid Line FP air and seawater exhaust line

Claims

1. In a tidal area where natural tidal currents occur at a specified depth below the sea surface and the flow velocity direction is a laminar flow in approximately the same direction, A predetermined width L in a direction perpendicular to the flow velocity direction of the natural tidal current and approximately parallel to the seabed surface. ０ and the predetermined width L ０ The length p is defined by the required depth difference d at the specified water depth from each of the left and right ends of the ０ A submarine facility for increasing the flow velocity of a tidal current in a predetermined sea area that forms a cube with three sides of lengths of x p x d, The predetermined width L of the predetermined sea area having a cubic shape ０ A plate-shaped subsea vertical float having a required length p, a height h of a required left-right thickness t and dimensions p x h x t is arranged along the left and right side surfaces of the cube in the specified sea area from each of the separated left and right end positions along the upstream of the natural tidal current, the subsea vertical float is connected with a wire to a large sea surface float floating on the sea surface above it to give it a large buoyancy upward, and is connected with a plurality of wires to a plurality of seabed anchors installed on the seabed surface below it to moor the subsea vertical float in a substantially vertical position in the sea, and further, A plurality of submarine vertical floats having the same structure and approximately the same dimensions t and h are arranged in a row in the upstream direction of the tidal current so that their leading and trailing ends are in contact with or continuous with each other at the upstream tip of the submarine vertical float, and the submarine vertical floats are arranged so that the left and right spacing between the submarine vertical floats arranged opposite each other widens the further up the tidal current they go, so that the left and right spacing between them widens in a V-shape, and each submarine vertical float is moored with a plurality of wires to a large surface float floating above, and also moored with a plurality of wires to a seabed anchor below so that it can be left stationary, The rows of submarine vertical floats are connected to each other with wires between the front and rear of each row, and between each pair of left and right submarine vertical floats, and each submarine vertical float is further moored to multiple seabed anchors installed on the front, rear, left and right sides of the float with wires extending in the left and right, front and rear, and up and down directions, so that the submarine vertical floats arranged in a V-shape in the direction of the tidal current can be moored and held in a V-shape, and the double row of V-shaped submarine vertical floats forms an underwater waterway that guides the tidal current to a specified sea area, and the underwater waterway formed by the V-shaped submarine vertical floats narrows the passage area of ​​the left and right submarine waterways, thereby accelerating the tidal current and resulting in a high tidal current speed in the specified sea area.

2. The subsea vertical wall float has an outer shell made of steel plate or strong metal and shaped into a vertical box with a short width, and the outer shell is filled with foamed resin in a predetermined ratio to form an approximately vertical float, and the outer surface of the subsea vertical wall float is structured to be resistant to breakage and have buoyancy.

3. 3. The underwater facility for increasing the flow velocity of a tidal current as claimed in claim 1 or 2, wherein a tidal current power generation device that generates electricity using tidal current energy is installed in a specified sea area downstream where the flow velocity of the tidal current has increased, thereby enabling high electrical output even at high tidal current speeds.

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