JP2023161973A - Water flow power generation device - Google Patents

Abstract

To efficiently generate power from water flow stably even in an environment where a direction of water flow changes.SOLUTION: A water flow power generation device 1 is composed of: a pillar; a hollow rotatable support 4 connected to the pillar; a rotor 8; a rotor support member 9 that supports the rotor 8; a shaft 11; and a generator 20. The shaft 11 that rotates together with the rotor passes through the inside of the rotor support member 9 and is connected to the generator 20.SELECTED DRAWING: Figure 4

Description

The present invention relates to a water current power generation device.

It is said that ocean currents contain several hundred TWh of energy each year around the world. Ocean currents are more stable than fluctuations in sunlight or wind power, so power generation using ocean currents is attracting attention as a stable power generation method. Furthermore, since ocean current power generation does not emit carbon dioxide (CO2), it is attracting attention as a natural energy power generation method with extremely low environmental impact.
BACKGROUND ART Conventionally, there has been a technology in which the kinetic energy of the water flow is converted into electrical energy to generate electricity by rotating a rotating body such as a propeller using the water flow of the sea or river.

Patent Document 1 describes a technology for generating electricity using tidal currents, in which a support rod is provided at a fixed position in the sea, a screw blade that rotates in response to the tidal current is provided on the support rod, and the rotational force of the screw blade is rotated by the tidal current. describes a technology for generating electricity by driving a generator in a station installed above the sea surface. The cylindrical rod supporting the screw blade is rotatably attached to the support rod so that the screw blade faces the tidal current.

Patent Document 2 describes a technology in which an underwater rotating body is arranged on a vertical member fixed to the seabed, and the rotational energy generated by the rotation of the underwater rotating body by an ocean current is transmitted to a generator on the sea. Since the underwater rotating body and the support part are connected by a universal joint mechanism, the rotating body can freely change direction in up, down, left and right directions.

Japanese Patent Application Publication No. 2002-257023 JP2009-121241A

However, in the invention of Patent Document 1, the transmission and generator are placed at a station floating on the sea, and the rotation of gears, etc. that transmits the rotational energy received by the screw blades from the tidal current to the transmission and generator on the sea. Requires force transmitting material. Transmitting rotation using a rotational force transmitting material may complicate the mechanism or cause energy loss.

In addition, the invention of Patent Document 2 can freely change the direction of the underwater rotating body according to changes in the direction of the ocean current, but since it is connected by a small contact point called a universal joint mechanism, there is no sufficient It is difficult to ensure strength and there is a risk of joint damage.

The present invention was made in view of this situation, and an object of the present invention is to stably and efficiently generate power from water flow even in an environment where the direction of water flow fluctuates.

The invention described in claim 1 includes: a hollow support; a hollow rotating support connected to the support and rotatable; a rotating body rotated by a water flow; one end fixed to the rotation support; A rotary body support member that supports a rotary body, and a shaft that is fixed to the rotary body and rotates together with the rotary body, and the shaft passes through an internal space of the rotary body support member and is connected to a generator. This is a water current power generation device characterized by the following.

In the invention described in claim 2, the rotary body support member has a cylindrical body extending in the direction of the rotation axis of the rotary body, and a convex portion protruding radially outward from the rotary body support member. 2. The water current power generation device according to claim 1, wherein the rotary body is rotatably supported by facing a recessed portion inside the rotary body.

The invention described in claim 3 is characterized in that the power transmission cable connected to the generator is laid in the internal space of the rotating body support member or the support column. This is the water current power generation device described above.

The invention described in claim 4 is the water current power generation device according to claim 1 or 2, wherein a rotatable angle range of the rotating support is less than 180 degrees.

The invention set forth in claim 5 is characterized in that a plurality of rotating body supporting members are fixed to the rotating support column, and each rotating body supporting member supports at least one or more rotating bodies. Alternatively, it is a water current power generation device according to claim 2.

According to the present invention, even in an environment where there is variation in the direction of water flow, power can be stably and efficiently generated from water flow.

It is a perspective view showing a water current power generation device concerning a first embodiment of the present invention. 1 is a sectional view of a water current power generation device according to a first embodiment of the present invention. It is a sectional view showing a water current power generation device concerning a second embodiment. It is a sectional view showing a water current power generation device concerning a third embodiment. It is a figure showing the water current power generation device concerning a fourth embodiment. FIG. 2 is a diagram showing an example in which a plurality of water current power generation devices according to the first or third embodiment are arranged. FIG. 7 is a diagram showing an example in which a plurality of water current power generation devices according to the second or fourth embodiment are arranged. It is a figure showing the example where multiple water current power generation devices concerning a third embodiment are arranged. It is a figure showing another example where a plurality of water current power generation devices concerning a third embodiment are arranged. It is a figure which shows the example which combined the water flow power generation device based on 3rd and 4th embodiment.

A power generation device according to the present invention will be explained with reference to the drawings. Note that the present invention is not limited to the embodiments described below.

(First embodiment)
FIG. 1 is a perspective view showing a water current power generation device according to a first embodiment of the present invention. As shown in FIG. 1, the water current power generation device 1 of the present embodiment includes a column 3, a rotating column 4, a column 5, an anchor 6, a mooring line 7, a rotating body 8, which extends vertically from a floating station 2 on the sea. It consists of a rotating body support member 9.

Station 2 is a facility that floats on the sea due to buoyancy. Since the support column 5 is connected to an anchor 6 installed on the seabed via a mooring cable 7, the water current power generation device 1 can be located at a fixed point without being washed away by the influence of ocean currents. The rotating body 8 receives the force of the ocean current and generates electricity by rotating. The rotating support 4 rotates so that the rotating body 8 and the rotating body support member 9 are located downstream of the rotating support 4 with respect to the direction of the ocean current.

In this specification, "water flow" refers to a flow of water or seawater, and includes not only a laminar flow direction in which streamlines are arranged in a layered manner, but also a turbulent flow state in which streamlines are disordered. "Direction of water flow" refers to the main direction of the entire flow, whether laminar or turbulent. Unless otherwise specified, "above" refers to the direction from the water bottom to above the water surface, and "downward" refers to the direction from above the water surface to the water bottom. Further, unless otherwise specified, "front" refers to the upstream direction of the water flow, and "rear" refers to the downstream direction of the water flow.

In this specification, a "rotating body" is an object or device that receives the force of a water flow and converts water flow energy into rotational energy. Therefore, it is desirable that the rotating body includes blades that can receive the water flow and turn it into rotation. The blade may be a propeller or may have a spiral shape diagonally with respect to the axial direction of the rotating body.

The rotating body 8 is a structure that can convert water flow energy into rotational energy of the rotating body 8. For example, in the example shown in FIG. 1, the rotating body 8 is installed downstream of the rotating column 4, and has a structure in which a plurality of blades 10 attached to the rotating body 8 rotate the rotating body 8 by receiving water flow. There is. Since it is desirable that the blade 10 has a shape that allows the rotating body to easily rotate in response to water flow, the blade 10 may be formed in a spiral shape surrounding the body of the rotating body.

By making the length of the rotor 8 in the rotational axis direction larger than the diameter in the radial direction (at the center of the body), the rotor 8 is rotated by the water flow and extends in the downstream direction, so it can not swing vertically. It is also possible to have a structure that is difficult to receive. In the first embodiment, the diameter of the rotating body 8 in the radial direction is about 10 m, and the length in the rotating axis direction is about 20 m. Further, as the material of the rotating body 8, resin or metal such as fiber reinforced plastic (FRP) or carbon fiber reinforced plastic (CFRP) is used. If the rotating body is made of titanium alloy, it will not rust even in water and can be used semi-permanently.

FIG. 2 is a sectional view of the water current power generation device according to the first embodiment. A rotating support 4 is rotatably arranged between the support 3 and the support 5. The connecting portion between the column 3 and the rotating column 4 is arranged such that the convex portion of the column 3 faces the concave portion of the rotating column 4, and is in contact with the bearing 16a. The connecting portion between the rotating strut 4 and the strut 5 also has the same configuration as the connecting portion between the rotary strut 4 and the strut 3. The rotating strut 4 freely rotates around the central axis of the strut so that the rotating body 8 can be positioned on the downstream side of the ocean current or facing upstream, depending on the direction of the ocean current. do. The rotating support 4 may be a mechanism that can freely rotate 360 degrees, but if the ocean current continues to rotate clockwise or counterclockwise, the power transmission cable will be twisted, so the rotation angle is limited by rotating around the main direction of the ocean current. , may be a predetermined angle less than 180°. As for the mechanism that restricts the angle of the rotating support, it may have a structure in which a stopper or the like is installed that prevents the rotation from rotating after a certain angle of rotation.

The rotating support 4 requires a hollow space for accommodating the power transmission cable 21 or the generator 20. It is desirable that the pillar 3 or the pillar 5 be hollow in order to secure a space in which the power transmission cable can be extended. When leading the power transmission cable to the seabed, at least the lower support column 5 is made hollow, and the power transmission cable is passed downward. On the other hand, when guiding the power transmission cable to a relay point on the sea, at least the upper support 3 may be hollow.

The rotating body 8 and the rotating body supporting member 9 are arranged so that the recess 12 inside the rotating body and the convex portion 13 of the rotating body supporting member 9 are engaged with each other, and are in contact with the bearings 14a and 14b. The rotating body support member 9 has a hollow shape. A shaft 11 fixed inside the rotating body 8 is housed in a hollow space of the rotating body support member 9, and is connected to a generator 20 arranged in the internal space of the rotating column 4. Therefore, the rotational energy of the rotating body 8 is transmitted to the generator 20 via the shaft 11, thereby generating electricity. "A shaft that transmits the rotation of a rotating body to a generator" includes not only a shaft that is directly connected to a generator, but also a shaft that transmits rotation to a generator via a transmission or the like.

The rotating body support member 9 is a cylindrical member extending parallel to the rotation axis of the shaft 11, and the shaft 11 passes through the inside of the rotating body supporting member 9. One end of the rotating body support member 9 is fixed to the rotating support 4 , and the other end is arranged to be housed inside the rotating body 8 . A convex portion 13 is formed on the outer periphery of the cylinder, projecting outward in the radial direction of the shaft from the outer wall surface of the rotary body support member 9 housed inside the rotary body 8 . The convex portion 13 is arranged so as to face the concave portion 12 formed in the shape of a groove on the inner wall surface of the rotating body 8 . As a result, even when the force of the water flow is strong, the rotating body 8 is supported by the convex portion 13 of the rotating body support member 9 fixed to the rotating column 4, and the rotating body 8 is not detached from the water current power generation device. It is possible to maintain rotational motion without being swept away in the downstream direction of the water flow.
Further, although not shown, the rotating body support member 9 may have a structure that is expandable and contractible while being fixed to the rotating support 4. If the structure is expandable and retractable, the distance of the rotating body 8 from the rotating column 4 can be adjusted, so the rotating body 8 can be placed at an optimal position where the resistance of the rotating column 4 in the water flow has little effect.

In this specification, "confronting" refers to a state in which opposing members fit into each other, but the opposing members do not necessarily have to be in contact with each other, and the opposing members facing each other are specified even though they are separated from each other. It also includes conditions that restrict the movement of. For example, "facing" includes a structure in which opposing members support each other via oil, bearings, or a combination thereof, even if the convex portion and the concave portion do not directly touch each other.

A plurality of bearings 14a and 14b may be arranged on the outer periphery of the cylinder of the support member on the front and rear sides of the convex portion 13. The rear bearing 14b is required to be strong enough to withstand the force of the water flow trying to sweep away the rotating body 8. The presence of the bearings 14a and 14b reduces resistance to the rotational movement of the rotating body 8, allowing it to rotate at a higher speed. Furthermore, by filling the space formed by the concave portion 12 and the convex portion 13 of the rotating body 8 with oil, the rotating body 8 can be rotated smoothly and stably. When filling the recess 12 with oil, a known technique may be used to provide a sealing structure that prevents oil from leaking.

The size and material of the concave portion 12 and the convex portion 13 are not particularly limited as long as they have the strength to withstand the force of the water flow applied to the rotating body 8 and maintain stable rotation. Additionally, if the depth of the recess 12 is greater than the height of the protrusion 13, the space between the recess 12 and the protrusion 13 can be filled with oil or bearings, allowing for smooth rotation. Become.

The bearing 14a on the front side of the protrusion 13 and the bearing 14b on the rear side of the protrusion 13 may or may not have the same size. The rear bearing 14b needs to have a larger diameter than the front bearing 14a because it needs to have enough strength to withstand the force of the water flow trying to wash away the rotating body 8 and at the same time maintain rotation. It can also be used as a bearing. By making the bearing 14b on the rear side larger than the bearing 14a on the front side, strong support can be provided against the force of the water flow pushing the rotating body backward.
Furthermore, the number of bearings 14b on the rear side of the protrusion 13 may be greater than the number of bearings 14a on the front side of the protrusion 13 arranged around the rotating body 8. By arranging many bearings 14b on the rear side of the convex portion 13, the number of points of contact between the convex portion 13 and the plurality of bearings 14b increases, so that support against the force of the water flow pushing the rotating body backward can be strengthened. , the effect of suppressing the swinging of the rotating body 8 can also be exhibited.

Further, a waterproof mechanism may be provided to prevent water from entering the cavity inside the rotating body 8. The waterproofing mechanism may be a known waterproofing technique. For example, as shown in FIG. It may have a structure that prevents water from entering the body.

In the example shown in FIG. 2, the rotating body 8 is provided with the concave portion 12, and the rotating body supporting member 9 is provided with the convex portion 13, but the relationship between the concave and convex portions may be reversed. That is, a concave portion may be provided on the rotating body support member 9 side, and a convex portion protruding radially inward from the inner wall surface of the rotary body may face the concave portion of the rotary body supporting member 9.

The rotating body of this embodiment is a downwind type rotating body that rotates on the downstream side of the rotating column 4. Since the speed of the ocean current decreases or the flow becomes turbulent due to the resistance of the rotating strut 4, it is desirable to arrange the rotating body 8 a certain distance from the rotating strut 4. It is desirable to arrange the rotating body at a distance that is at least equal to the diameter of the rotating column.

As described above, the water current power generation device according to the first embodiment can efficiently generate power even in an environment where the direction of the ocean current fluctuates while suppressing the rocking of the rotating body 8. Further, in the water current power generation device according to the first embodiment, since the shaft 11 that rotates together with the rotating body 8 is directly connected to the generator in the rotating support 4, when the generator 20 is installed on the sea, In comparison, there is less rotational energy loss due to a transmission mechanism using gears or the like.

(Second embodiment)
FIG. 3 is a sectional view showing a water current power generation device according to the second embodiment. The second embodiment is characterized in that when the rotating body 8 rotates under the force of the ocean current and generates electricity, the rotating body 8 is located upstream of the rotating support 4, that is, it is an upwind type. This is different from the first embodiment. In the first embodiment, since the rotating body 8 is located on the downstream side of the rotating column 4, the length of the rotating body supporting member 9 is It was necessary to make it long and streamlined. In the second embodiment, since the rotating body 8 is located upstream of the rotating support 4, there is no need to lengthen the rotating body support member 9 arranged downstream of the rotating body 8.
Further, it is desirable to provide a waterproof mechanism between the rotating body 8 and the rotating body support member 9. Although in FIG. 3 an O-ring 15 is provided, other known waterproofing mechanisms may be used, such as bellows, for example.

The rotating support 4 rotates so that the rotating body 8 faces the upstream direction by receiving the force of the ocean current. That is, the rotating support 4 rotates so that the rotating body 8 faces the ocean current. If a rotating body support member 9 is fixed in a specific direction to a non-rotating column instead of the rotating column 4, the rotating body 8 will receive the water flow from diagonally or horizontally. does not rotate efficiently and generates large vibrations, resulting in a decrease in power generation efficiency. In this embodiment, the rotating body 8 can be directed in the most efficient direction by rotating the rotating support 4, so that it is possible to efficiently generate power.

(Third embodiment)
FIG. 4 is a sectional view showing a water current power generation device according to a third embodiment. The third embodiment differs from the first embodiment in that the generator 20 is housed in the internal space of the rotating body support member 9 and that a transmission 30 is interposed between the generator 20 and the shaft 11. However, other configurations are the same as in the first embodiment.
By housing the generator 20 and the transmission 30 in the internal space of the rotating body support member 9, the length of the shaft 11 can be shortened, and the internal space of the rotating support 4 can be made small.

(Fourth embodiment)
FIG. 5 is a sectional view showing a water current power generation device according to the fourth embodiment. The fourth embodiment differs from the second embodiment in that the generator 20 is housed in the internal space of the rotating body support member 9 and that a transmission 30 is interposed between the generator 20 and the shaft 11. However, other configurations are the same as the second embodiment.
By housing the generator 20 and the transmission 30 in the internal space of the rotating body support member 9, the length of the shaft 11 can be shortened, and the internal space of the rotating support 4 can be made small.

(Embodiment with multiple rotating bodies arranged)
The water current power generation device according to the first embodiment and the water flow power generation device according to the third embodiment are devices in which the rotating body 8 is located downstream of the rotating support 4 and generates power. A plurality of water current power generation devices according to the first embodiment or the third embodiment can be arranged.
For example, in the case shown in FIG. 6, rotating bodies are arranged in series at three positions at different vertical depths. The direction of ocean currents may vary depending on the depth. In such a case, in this case, each rotating column 4 can be rotated so that the rotating body is located in the optimal direction at each different depth, so compared to a system in which the rotating body is fixed in a specific direction. This will improve the power generation efficiency as a whole.

The water current power generation device according to the second embodiment and the water flow power generation device according to the fourth embodiment are devices in which the rotating body 8 is located upstream of the rotating support 4 and generates power. A plurality of water current power generation devices according to the second embodiment or the fourth embodiment can be arranged.
For example, in the case shown in FIG. 7, rotating bodies are arranged in series at three positions at different vertical depths. The direction of ocean currents may vary depending on the depth. In such a case, in this case, each rotating column 4 can be rotated so that the rotating body is located in the optimal direction at each different depth, so compared to a system in which the rotating body is fixed in a specific direction. This will improve the power generation efficiency as a whole.

In the water current power generation device according to the third embodiment, the generator 20 was housed inside the rotating body support member 9. Here, the rotating body support member is not limited to a member that extends linearly from the rotating body toward the rotating column 4 as shown in FIG. 4. For example, FIG. 8 is a diagram showing an example in which a plurality of water current power generation devices according to the third embodiment are arranged. In this example, the rotating body support member 9 is configured by connecting members 9a, 9b, and 9c. Although not shown, each of the members 9a, 9b, and 9c has a hollow space inside, so the power transmission cable connected to the generator passes through the hollow space of the rotating body support member 9. can reach the inside of the column.

FIG. 9 is a diagram showing another example in which a plurality of water current power generation devices according to the third embodiment are arranged. In this example, three rotating bodies are arranged on a horizontal plane at the same depth. A generator is disposed within each rotating body support member. When the generators are arranged inside the rotating column 4, it is necessary to arrange three generators in the internal space of the rotating column 4 or to use a complicated transmission mechanism to transmit the rotation of each rotating body to the rotating column 4. In this case, the generator is placed inside each rotating body support member, and the power transmission cable from each generator can reach the inside of the rotating column 4 via the inside of each rotating body support member. There is no shortage of space inside the pillar.

FIG. 10 is a diagram showing an example in which the water current power generation devices according to the third and fourth embodiments are combined. If the rotating bodies are placed one behind the other at the same depth, the rear rotating body will be affected by changes in water flow caused by the front rotating body, so it is desirable to make the distance between the front and rear rotating bodies as long as possible.

Although the embodiments of this specification have been described as power generation devices using ocean currents in the sea, the present invention is not limited to ocean currents, and includes power generation devices in places where water flows, such as rivers and lakes.

DESCRIPTION OF SYMBOLS 1... Water current power generation device, 2... Station, 3... Support, 4... Rotating support, 5... Support, 6... Anchor, 7... Mooring rope, 8... Rotating body, 9... Rotating body support member, 10... Blade, 11... Shaft, 12... recess, 13... protrusion, 14a, 14b... bearing, 15... O ring, 16a, 16b... bearing, 20... generator, 21... power transmission cable, 30... transmission

Claims (5)

A hollow support and
a rotatable hollow rotating column connected to the column;
A rotating body rotated by water flow,
a rotating body support member having one end fixed to the rotating column and supporting the rotating body;
a shaft fixed to the rotating body and rotating integrally with the rotating body,
The shaft passes through the internal space of the rotating body support member and is connected to a generator.
A water current power generation device characterized by: The rotating body support member has a cylindrical body extending in the direction of the rotation axis of the rotating body,
2. The rotary body is rotatably supported by a convex portion protruding radially outward from the rotary body support member and a recessed portion inside the rotary body facing each other. Water current power generation device. 3. The water current power generation device according to claim 1, wherein a power transmission cable connected to the generator is laid in an internal space of the rotating body support member or the pillar. 3. The water current power generation device according to claim 1, wherein the rotatable angle range of the rotating support is less than 180 degrees. The water current power generation device according to claim 1 or 2, wherein a plurality of rotating body supporting members are fixed to the rotating support column, and each rotating body supporting member supports at least one rotating body. .

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