Underwater hydroelectric power generator and underwater hydroelectric power system

Abstract

The present invention relates to an underwater hydroelectric power generation device that uses water flow (ocean current, tidal current) to generate power output, and is configured to reduce the resistance of the water flow acting on the generator body. [Solution] The underwater water flow power generation device 1 of the present invention comprises at least a generator body 2 that obtains power output by utilizing rotational force, a rotating body 3 that rotates in response to the flow of water and imparts power (rotational force) to the generator body, and a fluid guide plate 4 arranged to guide the flow of water received by the rotating body in a predetermined direction. The generator body is installed on its back side so as to be covered by the fluid guide plate. The rotating body has a plurality of blades 35...35 along the rotational circumferential surface of a cylindrical drum 31 that rotates about a horizontal axis, and the fluid guide plate is inclined to cover the blades located above the rotation axis 33 of the rotating body and to guide the flow of water toward the blades located below the rotation axis of the rotating body.

Description

Technical Field

[0001] The present invention relates to an underwater installation type water flow power generation device configured to obtain power generation output by using water flow (ocean current, tidal current), and an underwater installation type water flow power generation system using this underwater installation type water flow power generation device, which is configured to reduce the resistance of the water flow received by the generator body.

Background Art

[0002] Recently, the spread of power generation systems using natural energy has been desired, and hydroelectric power generation using water flow (ocean current, tidal current) has been attracting attention in recent years. Most of the development of hydroelectric power generation devices is an application of wind power generation devices, and like wind power, it is a method of rotating a propeller with water flow. However, this method has a drawback that the energy loss is large because the energy direction is converted by 90 degrees to perform a rotational motion.

[0003] Power generation methods using water flow can be roughly divided into two categories. One is a system in which a windmill-like propeller machine is installed on the seabed or in the sea to generate electricity. The other is a system in which a power generation device moored by an anchor installed on the seabed or in the sea is floated in the sea and generates electricity by ocean currents.

[0004] The following formula based on fluid dynamics is the most important when considering these power generation systems using water flow.

[0005] Power generation amount = 1 / 2 × (seawater specific gravity) × (flow velocity)

[0007] , , × (blade area) × (power generation efficiency)

[0006] The important point in this formula is that the power generation amount is proportional to the cube of the flow velocity. Based on this power generation formula, in the case of the method of installing a propeller machine on the seabed, it is difficult to obtain a sufficient flow velocity, and the power generation amount decreases sharply.

[0007] To solve this problem, one possible method is to float power generation equipment, including propeller planes, as far away from the seabed as possible where the current is as fast as possible. However, this method has problems such as the difficulty in stabilizing the floating power generation equipment, including propeller planes, and the difficulty in increasing the density of power generation equipment.

[0008] Therefore, an underwater hydroelectric power generation system has been proposed that can efficiently obtain power output by utilizing natural energy sources such as water currents (ocean currents, tidal currents), and that can realize a stable supply of low-cost power generation based on a simple and inexpensive installation configuration (see, for example, Patent Document 1). Furthermore, turbine-type power generation devices that utilize water currents such as rivers and the sea to generate hydroelectric power have also been proposed (see, for example, Patent Document 2).

[0009] The above-described underwater hydroelectric power generation system is designed to reduce energy loss and efficiently generate power by providing an inclined plate on the water intake side of the power generation device, and by using the water flow along this inclined plate to rotate a variable-blade rotary impeller.

[0010] However, in conventional underwater hydroelectric power generation systems, as shown in Figure 8, the structure of the power generation device 101 is such that the generator body 102 is installed on top of the variable-blade rotary impeller 103, so the generator body 102 is subjected to resistance from the water flow. Furthermore, even if a cover such as a slanted plate 104 is provided on the front side of the generator body 102, it is not possible to sufficiently prevent resistance from the water flow. Therefore, in underwater hydroelectric power generation systems using such a power generation device 101, it was necessary to give sufficient consideration to the strength of the mooring devices such as wires and ropes that connect the anchor (weight) fixed to the seabed (seabed) and the power generation device 101 so that they could not withstand the resistance force of the water flow that the generator body 102 was subjected to. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Patent No. 5905984 [Patent Document 2] Patent No. 5389082 [Overview of the project] [Problems that the invention aims to solve]

[0012] The present invention was developed in view of the above-mentioned circumstances of the conventional invention, and aims to provide an underwater hydroelectric power generation device that utilizes water flow (ocean current) to obtain power output, configured to reduce the resistance of the water flow acting on the generator body, and an underwater hydroelectric power generation system using this underwater hydroelectric power generation device. [Means for solving the problem]

[0013] To achieve the above objective, a first aspect of the present invention is an underwater hydroelectric power generation device comprising at least a generator body that obtains power output by utilizing rotational force, a rotating body that rotates in response to the flow of water and imparts power to the generator body, and a fluid guide plate arranged to guide the flow of water received by the rotating body in a predetermined direction, wherein the generator body is installed on its back side so as to be covered by the fluid guide plate.

[0014] In the above-described underwater hydroelectric power generation device, the rotating body is preferably a cylindrical drum that rotates around a horizontal axis and has a plurality of blades along the circumferential surface in the direction of rotation, and the fluid guide plate is preferably arranged at an angle to cover the blades located above the rotation axis of the rotating body and to guide the flow of water toward the blades located below the rotation axis of the rotating body.

[0015] Furthermore, in the above-described underwater hydroelectric power generation device, the rotating body is a cylindrical drum that rotates around a horizontal axis and has a plurality of blades along the circumferential surface in the direction of rotation, and is arranged in a double configuration in the vertical direction, and the fluid guide plate comprises a first fluid guide plate that covers the blades located above the rotation axis of the first rotating body located below and is inclined to guide the flow of water toward the blades located below the rotation axis of the first rotating body, and a second fluid guide plate that covers the blades located below the rotation axis of the second rotating body located above and is inclined to guide the flow of water toward the blades located above the rotation axis of the second rotating body, and the generator body comprises a first generator body that receives power from the first rotating body located below and a second generator body that receives power from the second rotating body located above, and the first generator body is installed on its back side so as to be covered by the first fluid guide plate, and the second generator body is installed on its back side so as to be covered by the second fluid guide plate.

[0016] Furthermore, in the above-described underwater hydroelectric power generation device, the rotating body is a cylindrical drum that rotates around a horizontal axis and has a plurality of blades along the circumferential surface in the direction of rotation, and is arranged in a double configuration in the vertical direction, and the fluid guide plate comprises a first fluid guide plate that covers the blades located above the rotation axis of the first rotating body located below and is inclined to guide the flow of water toward the blades located below the rotation axis of the first rotating body, and a second fluid guide plate that covers the blades located below the rotation axis of the second rotating body located above and is inclined to guide the flow of water toward the blades located above the rotation axis of the second rotating body, and the generator body may receive power from the first rotating body located below and also from the second rotating body located above.

[0017] Another aspect of the present invention is an underwater water-power generation system comprising at least a weight fixed to the bottom of a watershed with a water flow, a power generation device moored above the weight via a mooring device, and a buoyancy body floating above the power generation device and applying tension to the power generation device via a tensioning device, wherein the power generation device is any of the underwater water-power generation devices described above.

[0018] In the above-described underwater hydroelectric power generation system, it is desirable that the power generation device incorporates a hollow tank that generates buoyancy equivalent to the weight of the power generation device into the cylindrical drum, and that its position is controlled in the watershed by the balance resulting from the interaction between the tension provided by the buoyancy body via the tensioning device and the buoyancy of the hollow tank.

[0019] Furthermore, in the above-described underwater hydroelectric power generation system, the power generation device may be installed in a frame having a water intake opening that allows the water flow to be taken in, and the frame may be connected to the mooring device such that the water intake opening always faces in a certain direction that faces the direction of the water flow, and the frame may be connected to the tensioning device such that the tension from the buoyancy body acts on the water intake opening side of the frame. [Effects of the Invention]

[0020] According to the present invention, the generator body is installed on the underwater hydroelectric power generation device that uses water flow (ocean current) to obtain power output, and is covered on the back side by a fluid guide plate that is arranged to guide the water flow acting on the rotating body in a predetermined direction. Therefore, similar to the water flow acting on a rotating body, the water flow acting on the generator body can be guided in a predetermined direction by a fluid guide plate, thereby reducing the resistance experienced by the generator body. As a result, the tension (i.e., resistance due to water flow) on the mooring devices such as wires and ropes connecting the anchor (weight) and the underwater hydroelectric power generation device can be reduced, thereby decreasing the required strength of the mooring devices.

[0021] Further, in a rotating body provided with a plurality of blades along the circumferential surface in the rotation direction of a cylindrical drum that rotates about a horizontal axis, if the fluid guide plate is arranged to be inclined so as to guide the flow of water toward the blades located below the rotation axis, the fluid guide plate covers the blades located above the rotation axis of the rotating body, thereby reducing the resistance received by the blades on the return side of the rotating body. At the same time, the flow of water guided by the fluid guide plate heads toward the blades located below the rotation axis, and the rotating body is efficiently rotated by the water flow along the fluid guide plate, reducing energy loss and enabling efficient power generation output to be obtained.

[0022] Furthermore, by installing the generator main body on the back side of the fluid guide plate, it is possible to form a submersible water flow power generation device with a structure in which another rotating body is installed above the rotating body and the rotating bodies are arranged in two in the vertical direction, enabling more efficient power generation output to be obtained. Moreover, when there is one rotating body, the resistance below this rotating body is greater (stronger) than the resistance above, and it is an unstable one without balance between the upper and lower parts. However, when two rotating bodies are provided vertically, the lower rotating body guides the flow of water by the fluid guide plate so as to head toward the blades located below the rotation axis, and the upper rotating body guides the flow of water by the fluid guide plate so as to head toward the blades located above the rotation axis. As a result, the resistance to the lower rotating body and the resistance to the upper rotating body become uniform (equal), and the submersible water flow power generation device can be made into a stable one with a good balance in which the magnitudes of the resistances are balanced between the upper and lower parts. Incidentally, it is also possible to adopt a structure in which the structures of the upper and lower rotating bodies are rotated by 90° and the rotating bodies are provided left and right.

Brief Description of the Drawings

[0023] [Figure 1] It is a schematic side view showing the configuration of the submersible water flow power generation device according to the present invention. [Figure 2] It is a (A) side view and (B) front view for explaining the configuration of the blades used in the submersible water flow power generation device shown in FIG. 1. [Figure 3]This is a schematic side view showing the overall configuration of the underwater hydroelectric power generation system according to the present invention. [Figure 4] This is a schematic side view showing another configuration of the underwater hydroelectric power generation device according to the present invention. [Figure 5] This is a schematic perspective view showing another configuration of the underwater hydroelectric power generation system according to the present invention. [Figure 6] Figure 5 is an enlarged perspective view showing the configuration of the underwater hydroelectric power generation device used in the underwater hydroelectric power generation system shown. [Figure 7] This is a schematic side view showing yet another configuration of the underwater hydroelectric power generation device according to the present invention. [Figure 8] This is a schematic side view showing the configuration of a conventional underwater hydroelectric power generation device. [Modes for carrying out the invention]

[0024] Hereinafter, an example of an underwater hydroelectric power generation device and underwater hydroelectric power generation system installed in a sea area will be described with reference to the drawings. The embodiments described below are preferred examples of the present invention and are subject to various technical limitations. However, the scope of the present invention is not limited to these forms unless otherwise specified in the following description.

[0025] <First Embodiment> As shown in Figure 1, the underwater water-flow power generation device 1 (hereinafter simply referred to as "water-flow power generation device") in this embodiment comprises at least a generator body 2, a rotating body 3, and a fluid guide plate 4.

[0026] The generator body 2 is a device that obtains power output by utilizing rotational force, and is a device that receives rotational energy generated by the rotating body 3 and converts it into electricity. The generator body 2 is positioned such that the side receiving the seawater flow (upstream) is covered by the fluid guide plate 4 on its underside. In other words, the fluid guide plate 4 reduces the resistance of the water flow that the generator body 2 experiences. In Figure 1, the generator body 2 is shown as having a rectangular parallelepiped shape.

[0027] The rotating body 3 is a device that rotates in response to the flow of seawater and imparts power (rotational force) to the generator body 2. This rotating body 3 consists of a cylindrical drum 31 that rotates around a horizontal axis, and side plates 32, 32 fixed to both sides of the cylindrical drum 31, with the outer diameter of the side plates 32 being larger than the outer diameter of the cylindrical drum 31.

[0028] Furthermore, the rotating body 3 is equipped with a plurality of blades 35 along the circumferential surface of the cylindrical drum 31 in the direction of rotation, and the rotating shaft 33 of the rotating body 3 to which the blades 35 are attached is rotatably supported via a bearing provided at the center of the side plate 32. In other words, the rotating body 3 has a structure similar to that of a waterwheel.

[0029] The blade 35 is a component that receives seawater in order to rotate the rotating body 3, and as shown in Figure 2, it consists of a short stopper portion 36 that abuts against the circumferential surface of the cylindrical drum 31 and a fluid receiving portion 37 that rises up from the stopper portion 36. This fluid receiving portion 37 is arranged to be upright so as to spread outward from the cylindrical drum 31 in order to efficiently receive the ocean current.

[0030] In other words, the blade 35 is attached to the boundary between the stopper portion 36 and the fluid receiving portion 37 by fixing the support shaft 38 with a fastener 39, and both ends of the support shaft 38 are rotatably supported by bearings arranged opposite each other on the respective sides 32, 32 of the cylindrical drum 31. Therefore, the blade 35 swings via the support shaft 38, and when it swings, the stopper portion 36 comes into contact with the circumferential surface of the cylindrical drum 31 of the rotating body 3, thereby limiting the range of upright movement of the fluid receiving portion 37.

[0031] The fluid receiving section 37 has a rounded, concave shape on the seawater receiving surface side so as to receive a large amount of seawater flow. Furthermore, when the blades 35 are folded in such a way that they fall, the fluid receiving portion 37 is long enough to cover the stopper portion 36 of the blade 35 on the side that falls and the lower part of the fluid receiving portion 37 (the side with the stopper portion 36).

[0032] Since this fluid receiving section 37 is longer and heavier than the stopper section 36, the blades 35, which are located above the rotating shaft 33, fold down naturally due to their own weight. In other words, when the blade 35 is tilted, the area of ​​the fluid receiving section 37 that receives the flow of seawater becomes significantly smaller, thus reducing the resistance experienced by the blade 35 located above the rotating shaft 33. Furthermore, when a blade 35 is tilted, the fluid receiving portion 37 folds down to cover the stopper portion 36 of the next (successor) blade 35 and the lower part of the fluid receiving portion 37, thus reducing the resistance of the blade 35 to the flow of seawater.

[0033] Furthermore, a hollow tank 34 is provided inside the rotating body 3 to form a sealed gas chamber. This hollow tank 34 is, for example, a cylindrical sealed hollow frame made of stainless steel, and is fixed to the rotating shaft 33. Furthermore, the hollow tank 34 is sealed with either air or a gas with high buoyancy, such as nitrogen or carbon dioxide.

[0034] In this way, by forming a sealed gas chamber inside the rotating body 3, buoyancy is generated in the rotating body 3, and the load on the bearing from the weight of the rotating body 3 and the blades 35 attached to the rotating body 3 can be reduced. Preferably, the volume of this sealed gas chamber is made large enough to obtain buoyancy that matches the weight of the rotating body 3 and the weight of the blades 35 attached to the rotating body 3.

[0035] The fluid guide plate 4 is a component arranged to guide the flow of seawater received by the rotating body 3 in a predetermined direction. Together with the generator body 2, it covers the front part (the side that receives the flow of seawater) of the blades 35 located above the rotation axis 33 of the rotating body 3, and is inclined to guide the flow of seawater toward the blades 35 located below the rotation axis 33 of the rotating body 3. In other words, the fluid guide plate 4 is provided to reduce the resistance of the water flow experienced by the generator body 2, as well as to reduce the resistance of the water flow experienced by the blades 35 located above the rotation axis 33 of the rotating body 3.

[0036] The seawater whose flow direction has been changed by the fluid guide plate 4 flows together with the seawater flowing below the fluid guide plate 4 toward the blades 35 located below the rotation axis 33 of the rotating body 3. This seawater then strikes the fluid receiving portion 37 of the blades 35, causing the rotating body 3 to rotate. As shown by the dashed arrow in Figure 1, the rotating body 3 rotates counterclockwise. As a result, the power (rotational force) of the rotating shaft 33 is transmitted (applied) to the generator body 2 via a transmission member such as a belt or chain, and the generator body 2 uses this rotational force to generate power output.

[0037] Furthermore, if the fluid guide plate 4 is not provided, the water flow will hit the return-side blades 35 of the rotating body 3 (i.e., the blades located above the rotation axis 33), and the rotating body 3 will hardly rotate at all. However, by providing the fluid guide plate 4, the water flow is prevented from hitting the return-side blades 35 of the rotating body 3, allowing the rotating body 3 to rotate efficiently. In this case, the speed of the water flow along the fluid guide plate 4 is 2 / √3 = 1.16 times the actual flow velocity (the flow velocity of the water flow that does not flow along the fluid guide plate 4), and the amount of power generated is 1.56 times greater. Therefore, by providing the fluid guide plate 4, the amount of power generated can be increased in proportion to the cube of the actual flow velocity, thus enabling efficient power output.

[0038] The hydroelectric power generation device 1 configured as described above is used in the underwater hydroelectric power generation system 10 shown in Figure 3 by attaching it to the frame 5. In other words, the frame 5 is a component that integrally supports the generator body 2, rotating body 3, and fluid guide plate 4 that make up the water flow power generation device 1.

[0039] This frame 5 is, for example, formed in a three-dimensional grid shape that does not obstruct the flow of seawater, and is equipped with a water flow intake opening 51 on the upstream side that receives the flow of seawater, which allows the flow of seawater to be taken in. Therefore, the hydroelectric power generator 1 has a fluid guide plate 4 attached to the frame 5 such that it slopes downward as it moves inward from the water intake opening 51 towards the downstream side, and the generator body 2 is attached to the back side of the fluid guide plate 4, and further, the rotating body 3 is attached to the downstream side. Here, the fluid guide plate 4 is long enough to guide the seawater flow to the blades 35 below the rotation axis 33 of the rotating body 3.

[0040] As shown in Figure 3, the underwater hydroelectric power generation system 10 in this embodiment is designed to generate power using ocean currents and comprises at least a hydroelectric power generation device 1 attached to a frame 5, a weight 12, and a buoyancy body 14.

[0041] The aforementioned weight 12 is a so-called anchor that is fixedly installed at the bottom of a watershed where there is a current of seawater, and the hydroelectric power generation device 1 is moored above the weight 12 via a mooring device 13 such as a wire or rope. In other words, the hydroelectric power generation device 1 is connected to the weight 12 using a mooring device 13 and is positioned above the weight 12.

[0042] For example, when the ballast 12 is fixedly installed on the seabed in an area with an ocean current of 1 m / s to 3 m / s, it can have a weight of 5 tons. The mooring device 13 should be designed to withstand a tensile strength of 10 tons or more.

[0043] As shown in Figure 3, the connection between the weight 12 and the water-power generation device 1 by the mooring device 13 is achieved by, for example, connecting one end of the four-part mooring device 13 to the lower left and right corners on the water intake opening 51 side of the frame 5 on which the water-power generation device 1 is installed, and to both lower left and right ends on the way toward the rotating body 3. Furthermore, the four-part mooring device 13 is combined into a single unit at an intermediate position between it and the weight 12, and the other end of this combined mooring device 13 is connected to the weight 12. In this way, by tethering the hydroelectric power generator 1 to the weight 12 via the mooring device 13, the hydroelectric power generator 1 can be prevented from being washed away.

[0044] The buoyancy body 14 is of the type that floats in the sea and is connected to the hydroelectric power generation device 1 using a tensioning device 15 such as a wire or rope. It is positioned above the hydroelectric power generation device 1 so as to apply tension to the hydroelectric power generation device 1 via the tensioning device 15.

[0045] More specifically, the frame 5 and the buoyancy body 14 are connected such that tension from the buoyancy body 14 is applied to the area from the tip side forming the water flow intake opening 51 of the frame 5 to approximately the middle section. This is because the area of ​​the frame 5 where the water flow power generator 1 is attached has buoyancy because the rotating body 3 has a hollow tank 34 built inside. Therefore, the frame 5 and the buoyancy body 14 are connected via a tensioning device 15 so that tension from the buoyancy body 14 is applied only to the area of ​​the frame 5 where the fluid guide plate 4 is attached, excluding this area.

[0046] Specifically, the left and right lower corners of the front part (the side receiving the seawater flow) of the buoyancy body 14 are connected to the left and right upper corners of the frame 5 on the side of the water flow intake opening 51 by two tensioning devices 15, 15, and the left and right lower corners of the rear part of the buoyancy body 14 are connected to the left and right upper sides of the frame 5 approximately in the middle by two tensioning devices 15, 15. The pulling device 15 used is, for example, one that can withstand a tensile strength of 10 tons or more.

[0047] As a result, the interaction between the buoyancy balance of the hydroelectric power generation device 1 by the hollow tank 34 and the tension applied to the frame 5 via the tensioning device 15 by the buoyancy body 14 controls the position of the hydroelectric power generation device 1 so that the water intake opening 51 of the frame 5 always faces in a constant direction that is opposite to the direction of the ocean current.

[0048] As described above, in the underwater hydroelectric power generation system 10 of this embodiment, by combining the cone 12 and the buoyancy body 14, the hydroelectric power generation device 1 does not move around in the water, and it can be installed very simply and inexpensively without requiring complicated installation work. Moreover, it is possible to stably install the hydroelectric power generation device 1 in seawater, and it is also possible to install it in sea areas where there are ocean currents with high current velocities such as the Kuroshio Current.

[0049] Furthermore, according to the underwater hydroelectric power generation system 10 of this embodiment, the position of the water flow intake opening 51 in the frame 5 is controlled so that it always faces a certain direction opposite to the direction of the ocean current. As a result, the fluid guide plate 4 of the hydroelectric power generation device 1 is positioned to face the same direction as the flow of seawater flowing in from the water flow intake opening 51, and as shown by the white arrow in Figure 3, the flow of seawater can be guided in the direction of the blades 35 of the rotating body 3.

[0050] Furthermore, by installing the generator body 2 on the back side of the fluid guide plate 4, unused space is effectively utilized to reduce water resistance on the water-flow power generation device 1, preventing an increase in tension in the mooring device 13 connecting the weight 12 and the water-flow power generation device 1, thereby reducing the required strength and enabling cost reductions such as reducing the thickness of the mooring device 13. Furthermore, by efficiently rotating the rotating body 3, the loss of ocean current energy can be reduced. In addition, the blades 35 of the rotating body 3 have a variable wing structure that folds down when not flowing against the ocean current, thus minimizing rotational loss.

[0051] <Second Embodiment> Furthermore, in the present invention, multiple rotating bodies 3 can be provided to obtain a large power generation output. In other words, it differs from the first embodiment described above in that the rotating bodies 3 are arranged in a double configuration in the vertical direction.

[0052] In the other embodiments described below, the focus will be on the differences from the first embodiment described above. Therefore, components similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted. Unless otherwise specified, they will be considered identical.

[0053] As shown in Figure 4, the water flow power generation device 11 in this embodiment comprises at least two generator bodies 2A and 2B arranged vertically, two rotating bodies 3A and 3B arranged vertically, and two fluid guide plates 4A and 4B arranged vertically. Hereinafter, the generator body located at the bottom will be referred to as the lower generator body 2A, and the generator body located at the top will be referred to as the upper generator body 2A. Furthermore, the rotating body located at the bottom will be referred to as the lower rotating body 3A, and the rotating body located at the top will be referred to as the upper rotating body 3B. In addition, the fluid guide plate located at the bottom will be referred to as the lower fluid guide plate 4A, and the fluid guide plate located at the top will be referred to as the upper fluid guide plate 4B.

[0054] The hydroelectric power generator 11 has a vertical double-stage structure comprising a lower rotating body 3A and an upper rotating body 3B, and the upper rotating body 3B is positioned so that its direction of rotation is different from that of the lower rotating body 3A. Specifically, as shown by the dashed arrow in Figure 4, the lower rotating body 3A rotates counterclockwise, and the upper rotating body 3B rotates clockwise.

[0055] Furthermore, the lower fluid guide plate 4A is positioned at an angle to cover the blades 35 located above the rotation axis 33 of the lower rotating body 3A, while guiding the flow of seawater toward the blades 35 located below the rotation axis 33 of the lower rotating body 3A. On the other hand, the upper fluid guide plate 4B is positioned at an angle to guide the flow of seawater toward the blades 35 located above the rotation axis 33 of the upper rotating body 3B, while covering the blades 35 located below the rotation axis 33 of the upper rotating body 3B.

[0056] The lower generator body 2A is installed on the lower side of the partition 52, which is provided to separate the lower rotating body 3A from the upper rotating body 3B, and is covered by the lower fluid guide plate 4A, receiving power from the lower rotating body 3A. On the other hand, the upper generator body 2B is also installed on the upper side of the partition 52, on the back side so as to be covered by the upper fluid guide plate 4B, and receives power from the upper rotating body 3B. In other words, the two generator bodies 2A and 2B are installed on the back side of the respective fluid guide plates 4A and 4B, so that they are covered by separate fluid guide plates 4A and 4B.

[0057] The blades 35 of the lower rotating body 3A and the upper rotating body 3B may be the same as those in the first embodiment described above, or they may be of a different structure and shape. For example, in the case of the blades 35 of the upper rotating body 3B, if the specific gravity of the fluid receiving portion 37 is made lighter than that of the stopper portion 36, the blades 35 located above the rotating shaft 33 will expand so that the fluid receiving portion 37 stands upright due to the water flow guided by the upper fluid guide plate 4B, while the blades 35 located below the rotating shaft 33 will fold down due to the specific gravity of the stopper portion 36 and the contact of the fluid receiving portion 37 with the partition provided to separate the lower rotating body 3A and the upper rotating body 3B.

[0058] The hydroelectric power generation device 11 configured as described above is attached to the frame 6 and used in the underwater hydroelectric power generation system 20 shown in Figures 5 and 6. As shown in Figure 5, the underwater hydroelectric power generation system 20 in this embodiment is designed to obtain a large power output by utilizing ocean currents, and comprises at least a hydroelectric power generation device 11 attached to a frame 6, a weight 12, and a buoyancy body 14.

[0059] The frame 6 is formed, for example, in a three-dimensional grid shape that does not obstruct the flow of seawater, and as shown in Figure 6, it is provided with an intermediate frame 6a that divides the internal area into upper and lower sections at approximately the midpoint in the height direction, and on the upstream side that receives the flow of seawater, it is provided with water flow intake openings 51 in the upper and lower regions, respectively, that allow the flow of seawater to be taken in. Furthermore, the frame 6 is equipped with a partition 52 that spans across the middle frame 6a, which divides the internal area vertically.

[0060] The weight 12 is moored to the water-powered generator 11 above it via a mooring device 13 such as a wire or rope. Specifically, one end of the mooring device 13, which is divided into four sections, is connected to both the left and right lower corners on the water intake opening 51 side of the frame 6 to which the water-powered generator 11 is attached, and to both the left and right lower sides approximately midway towards the rotating body 3. Furthermore, the four-part mooring device 13 is combined into a single unit at an intermediate position between it and the weight 12, and the other end of this combined mooring device 13 is connected to the weight 12.

[0061] The buoyancy device 14 is connected to the hydroelectric power generator 11 using a tensioning device 15 such as a wire or rope, and is positioned above the hydroelectric power generator 11 so as to apply tension to the hydroelectric power generator 11 via the tensioning device 15. Specifically, the left and right lower corners of the front part (the side receiving the seawater flow) of the buoyancy body 14 are connected to the left and right upper corners on the water flow intake opening 51 side of the frame 6 by two tensioning devices 15, 15, and the left and right lower corners of the rear part of the buoyancy body 14 are connected to the left and right upper sides of the frame 6 approximately in the middle by two tensioning devices 15, 15.

[0062] As a result, the interaction between the buoyancy balance of the hydroelectric power generation device 11 by the hollow tank 34 and the tension applied to the frame 6 via the tensioning device 15 by the buoyancy body 14 controls the position of the hydroelectric power generation device 11 so that the water intake openings 51, 51 of the frame 6 always face a certain direction opposite to the ocean current.

[0063] As described above, in the underwater hydroelectric power generation system 20 of this embodiment, the hydroelectric power generation device 11 does not move around in the water by combining the cone 12 and the buoyancy body 14, and it can be installed very simply and inexpensively without requiring complicated installation work. Moreover, since the hydroelectric power generation device 11, which is stably installed in seawater, is equipped with two rotating bodies 3A and 3B, the overall power generation efficiency is increased, and it becomes possible to obtain a large power output. Furthermore, in this underwater hydroelectric power generation system 20, the resistance experienced by the lower rotating body 3A and the upper rotating body 3B becomes uniform (equal), and the hydroelectric power generation device 11 is balanced vertically.

[0064] <Third Embodiment> Furthermore, in the present invention, when multiple rotating bodies 3 are provided, the generator body 2 can be shared to obtain a large power output. In other words, it differs from the first embodiment described above in that the rotating body 3 is arranged in a double configuration in the vertical direction, and it differs from the second embodiment described above in that there is only one generator body 2.

[0065] As shown in Figure 7, the water flow power generation device 21 in this embodiment comprises at least one generator body 2, two rotating bodies 3A and 3B arranged vertically, and two fluid guide plates 4A and 4B arranged vertically. Hereinafter, the rotating body located below will be referred to as the lower rotating body 3A, and the rotating body located above will be referred to as the upper rotating body 3B. Furthermore, the fluid guide plate located below will be referred to as the lower fluid guide plate 4A, and the fluid guide plate located above will be referred to as the upper fluid guide plate 4B.

[0066] The hydroelectric power generator 21 has a vertical double-stage structure comprising a lower rotating body 3A and an upper rotating body 3B, and the upper rotating body 3B is positioned so that its direction of rotation is different from that of the lower rotating body 3A. Specifically, as shown by the dashed arrow in Figure 7, the lower rotating body 3A rotates counterclockwise, and the upper rotating body 3B rotates clockwise.

[0067] Regarding the blades 35 of the lower rotating body 3A and the upper rotating body 3B, as with the second embodiment described above, those equivalent to those in the first embodiment described above may be used, or those with other structures and shapes may be used.

[0068] Furthermore, the lower fluid guide plate 4A is positioned at an angle to guide the flow of seawater toward the blades 35 located above the rotation axis 33 of the lower rotating body 3A, while covering the blades 35 located above the rotation axis 33 of the lower rotating body 3A. On the other hand, the upper fluid guide plate 4B is positioned at an angle to guide the flow of seawater toward the blades 35 located above the rotation axis 33 of the upper rotating body 3B, while covering the blades 35 located below the rotation axis 33 of the upper rotating body 3B.

[0069] The generator body 2 is installed on its underside so as to be covered by the lower fluid guide plate 4A and the upper fluid guide plate 4B, and receives power from the lower rotating body 3A and the upper rotating body 3B. In other words, the generator body 2 is designed to handle everything with just one unit, and receives the rotational energy generated by either the lower rotating body 3A or the upper rotating body 3B via a belt 7 that is attached in a figure-eight pattern. In Figure 7, the belt 7 that transmits the rotational energy generated by the upper rotating body 3B to the generator body 2 is shown as being installed in a figure-eight pattern.

[0070] The hydroelectric power generation device 21 configured as described above can also be used as an underwater hydroelectric power generation system by attaching it to a frame, although this is not shown in the diagram. Furthermore, in this embodiment of the underwater hydroelectric power generation system, the inclusion of two rotating bodies 3A and 3B increases the overall power generation efficiency, making it possible to obtain a large power output, while also reducing the weight due to the smaller size of the generator itself.

[0071] <Other Embodiments> Although not shown in the illustrations, in addition to the embodiments described above, a generator structure with two rows of generators arranged in two stages, one above the other and the other below, rotated 90 degrees, and a dual-row structure in which the rotating bodies are installed side by side are also possible. In other words, the rotating bodies are arranged in a dual configuration in the lateral (horizontal) direction, and the fluid guide plate is inclined to cover the blades located above the rotation axes of the two rotating bodies, which are positioned to the left and right respectively, while guiding the water flow toward the blades located below the rotation axes of the two rotating bodies. The generator body can be an underwater-installed hydroelectric power generator that receives power from the two rotating bodies, which are positioned to the left and right respectively.

[0072] In this case, the generator body may comprise a left-hand generator body that receives power from a left-hand rotating body located on the left, and a right-hand generator body that receives power from a right-hand rotating body located on the right, with both the left-hand and right-hand generator bodies being installed on their backs so as to be covered by the same fluid guide plate.

[0073] Furthermore, the rotating bodies are not limited to a two-unit horizontal configuration with the bodies placed side by side, but may also be a three-unit horizontal configuration, a four-unit horizontal configuration, and so on, as a multi-unit horizontal configuration. In this way, by arranging the rotating bodies in a horizontal multi-unit structure, the overall power generation efficiency of the hydroelectric power generation system is increased, making it possible to obtain a large power output. [Industrial applicability]

[0074] The underwater hydroelectric power generator and underwater hydroelectric power generation system according to the present invention can be used not only in the sea but also in bodies of water such as rivers with a stable water flow to efficiently obtain power output. [Explanation of symbols]

[0075] 1,11,21 Underwater hydroelectric power generation device 2. Generator body 3. Rotating bodies 4. Fluid guide plate 5,6 frames 7 belts 10,20 Underwater hydroelectric power generation system 12. Anchor 13. Mooring devices 14 Buoyancy devices 15 Pulling tool 31 Cylindrical drum 32 Side panels 33 Rotation axis 34 Hollow tank 35 feathers 36 Stopper section 37 Fluid receiving section 38 Spindle 39 Fixtures 51 Water intake opening 52 dividers

Claims

1. A generator body that uses rotational force to generate power output, A rotating body that rotates in response to the flow of water and provides power to the generator body, A fluid guide plate is arranged to guide the flow of water acting on the rotating body in a predetermined direction, It has at least the following features: The generator body is installed on its back side so as to be covered by the fluid guide plate. An underwater hydroelectric power generation device characterized by the following features.

2. The rotating body is a cylindrical drum that rotates around a horizontal axis and has multiple blades along the circumferential surface in the direction of rotation. The fluid guide plate is positioned at an angle to cover the blades located above the rotation axis of the rotating body, and to guide the flow of water toward the blades located below the rotation axis of the rotating body. The underwater water flow power generation device according to feature 1.

3. The rotating body comprises a plurality of blades along the circumferential surface in the direction of rotation of a cylindrical drum that rotates about a horizontal axis, and is arranged in a double row in the vertical direction. The fluid guide plate comprises a first fluid guide plate positioned at an angle to guide the flow of water toward the blades positioned below the rotation axis of a first rotating body located below it, while covering the blades positioned below the rotation axis of a first rotating body located below it, and a second fluid guide plate positioned at an angle to guide the flow of water toward the blades positioned above the rotation axis of a second rotating body located above it. The generator body comprises a first generator body that receives power from the first rotating body located below, and a second generator body that receives power from the second rotating body located above. The first generator body is installed on its back side so as to be covered by the first fluid guide plate. The second generator body is installed on its back side so as to be covered by the second fluid guide plate. The underwater water-powered generator according to feature 1.

4. The rotating body comprises a plurality of blades along the circumferential surface in the direction of rotation of a cylindrical drum that rotates about a horizontal axis, and is arranged in a double row in the vertical direction. The fluid guide plate comprises a first fluid guide plate positioned at an angle to guide the flow of water toward the blades positioned below the rotation axis of a first rotating body located below it, while covering the blades positioned below the rotation axis of a first rotating body located below it, and a second fluid guide plate positioned at an angle to guide the flow of water toward the blades positioned above the rotation axis of a second rotating body located above it. The generator body receives power from the first rotating body located below it, and also receives power from the second rotating body located above it. The underwater water-powered generator according to feature 1.

5. A weight that is fixedly installed at the bottom of a watershed where water flows, A power generation device is moored above the aforementioned weight via a mooring device, A buoyancy body is installed above the power generation device, and tension is applied to the power generation device via a tensioning device, It has at least the following features: The power generation device is an underwater-installed hydroelectric power generation device according to any one of claims 1 to 4. An underwater hydroelectric power generation system characterized by the following features.

6. The power generation device incorporates a hollow tank that generates buoyancy equivalent to the weight of the power generation device into the cylindrical drum, and is configured to control its position in the watershed by the balance between the interaction between the tension provided by the buoyancy body via the tensioning device and the buoyancy of the hollow tank. The underwater hydroelectric power generation system according to feature 5.

7. The power generation device is installed within a frame having a water flow intake opening that allows the water flow to be taken in. The frame is connected to the mooring device such that the water intake opening always faces a certain direction that is opposite to the direction of the water flow, and is connected to the tensioning device such that the tension from the buoyancy body acts on the water intake opening side of the frame. The underwater hydroelectric power generation system according to feature 6.

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