JP2012041920A - Ocean-current power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ocean-current power generation system that has less impact on the environment and reduces the death of fish due to the collision therewith.SOLUTION: The ocean-current power generation system includes: blades 2 for converting seawater current into rotation energy; a power generator enclosed in a nacelle 1, and for generating power with the converted rotation energy given via a rotating shaft connected to the blades 2; and a cap 4 provided to cover a certain radius from the rotation center connected to the rotating shaft in the blades 2 to the outer diameter. The cap 4 has a conical shape.

Description

  The present invention relates to an ocean current power generation system.

  There are many power generation systems using water, such as water turbines using height differences such as dams, ocean wave power, power generation using tides, power generation using osmotic membranes and temperature differences. A power generation system that can easily obtain large-capacity energy other than a power generation system that uses a difference in height is a power generation system that uses energy of tidal currents or ocean currents. However, large-capacity machines are not yet common and are being developed ahead of parts of Europe.

  FIG. 32 shows a schematic configuration of a mooring type ocean current power generation system, and a basic concept thereof will be described. This system includes a blade 102 that converts a flow into rotational energy, a rotating shaft that covers the portion connected to the blade 102 with a cap 106 and transmits the rotational energy to the generator, and the generator is included in the nacelle 101. ing. The nacelle 101 is supported by a structural member 103, and the structural member 103 is fixed to the sea floor by an anchor 105 via a mooring wire 104.

  FIG. 33 shows a schematic configuration of the fixed ocean current power generation system. The wing 102 and the nacelle 101 have the same structure as that in the mooring type ocean current power generation system shown in FIG. 32, but a support column 112 is used to fix the nacelle 101 to the seabed. In both mooring and stationary ocean current power generation systems, a cap 106 having a shape as illustrated is often used as often seen in wind turbines.

  The locations where ocean current power generation can be carried out in the waters near Japan are limited, and mainly include the Kuroshio Current, Tsushima Current, Oyashio Current, etc. On the other hand, tidal current power generation uses the flow of the tide, and the tide in the Naruto Strait is the largest. Both tidal current and ocean current power generation systems have a great impact on the surrounding environment, and these points are used as fishing grounds supported by abundant plankton. For this reason, when constructing a new power generation system, it is necessary to give sufficient consideration to those who live in the fishery industry so that environmental destruction caused by ecosystem disruption does not occur.

  Below, the literature name which disclosed the conventional ocean current power generation system is described.

US Pat. No. 7,530,224 US Pat. No. 7,425,772

  As described above, it is necessary to construct an ocean current power generation system with little environmental impact, and the impact on the ecosystem is particularly important.

  If a normal power generation system, especially a windmill, is applied as ocean current power generation, fish may collide with the power generation system and die, and the death of the fish may affect the ecosystem, such as the decline of its predators. .

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a ocean current power generation system that reduces the collision and death of fish and has less environmental impact.

The ocean current power generation system of the present invention includes a wing for converting the flow of seawater into rotational energy,
In the ocean current power generation system comprising the converted rotational energy supplied through a rotating shaft connected to the wing to generate electric power and a generator contained in a nacelle, the rotating energy is connected to the rotating shaft in the wing. And a cap provided so as to cover a predetermined radius from the center of rotation to the outer diameter side, wherein the cap has a conical shape.

  According to the ocean current power generation system of the present invention, it is possible to provide a ocean current power generation system that reduces the mortality due to the collision of fish and has little influence on the environment.

The front view which showed the structure of the ocean current power generation system by Embodiment 1 of this invention. The front view which showed the structure in the modification of the ocean current power generation system by the same Embodiment 1. FIG. The front view which showed the structure of the ocean current power generation system by Embodiment 2 of this invention. The left view which showed the structure of the ocean current power generation system by Embodiment 3 of this invention. The left view which showed the structure in the modification of the ocean current power generation system by Embodiment 3. FIG. The front view which showed the structure of the ocean current power generation system by Embodiment 4 of this invention. The front view which showed the structure in the modification of the ocean current power generation system by Embodiment 4. FIG. The front view which showed the structure in the other modification of the ocean current power generation system by the same Embodiment 4. FIG. The front view which showed the structure in the other modification of the ocean current power generation system by the same Embodiment 4. FIG. The front view which showed the structure in the other modification of the ocean current power generation system by the same Embodiment 4. FIG. The enlarged view which showed the structure of the wing | blade in FIG. Sectional drawing which showed the cross-sectional structure which follows the AA line in FIG. The front view which showed the structure of the ocean current power generation system by Embodiment 5 of this invention. The front view which showed the structure of the ocean current power generation system by Embodiment 6 of this invention. The left view which showed the shape of the wing | blade and cap of the ocean current power generation system by the Embodiment 6. FIG. The enlarged view which showed a part of shape of the wing | blade and cap of the ocean current power generation system by the Embodiment 6. FIG. The front view which showed the structure of the ocean current power generation system by Embodiment 7 of this invention. The left view which showed the shape of the wing | blade and cap of the ocean current power generation system by the Embodiment 7. FIG. The enlarged view which showed a part of shape of the wing | blade and cap of the ocean current power generation system by Embodiment 7. FIG. The front view which showed the structure of the ocean current power generation system by Embodiment 8 of this invention. The left view which showed the shape of the wing | blade and cap of the ocean current power generation system by the same Embodiment 8. FIG. The front view which showed the structure of the ocean current power generation system by Embodiment 9 of this invention. The left view which showed the shape of the wing | blade and cap of the ocean current power generation system by Embodiment 9 of this invention. The front view which showed the structure of the ocean current power generation system by the 1st modification of the Embodiment 9. FIG. The left view which showed the shape of the wing | blade and cap of the ocean current power generation system by the 1st modification of the Embodiment 9. FIG. The left view which showed the shape of the wing | blade and cap of the ocean current power generation system by the 2nd modification of the Embodiment 9. FIG. The left side view which showed the shape of the wing | blade and cap of the ocean current power generation system by the 3rd modification of the embodiment 9. Explanatory drawing which showed the cross-sectional shape of the cap of the ocean current power generation system by the 3rd modification of the Embodiment 9. FIG. The external view which showed the structure of the ocean current power generation system by Embodiment 10 of this invention. Explanatory drawing which showed the shape of the wing | blade and cap of the ocean current power generation system by Embodiment 10. FIG. The external view which showed the structure of the ocean current power generation system by the modification of the same Embodiment 10. FIG. The figure which showed schematic structure of the mooring type ocean current power generation system. The figure which showed schematic structure of the fixed type ocean current power generation system.

  Hereinafter, an ocean current power generation system according to an embodiment of the present invention will be described with reference to the drawings. In addition, the ocean current power generation system described here includes, in addition to the ocean current power generation system that uses ocean currents, a tidal current power generation system that uses tidal currents.

(1) Embodiment 1
An ocean current power generation system according to Embodiment 1 of the present invention will be described with reference to FIG.

  FIG. 1 shows main components of the ocean current power generation system according to the first embodiment. This system includes a wing 2 that converts ocean current flow into rotational energy, a rotating shaft that transmits the converted rotational energy to a generator, and a generator that is connected to the rotating shaft and receives rotational energy to generate power, The generator is included in the nacelle 1.

  Further, on the front side of the blade 2, that is, on the upstream side of the blade 2, a cap 4 having a conical shape that is concave inward is provided so as to cover a predetermined radius from the center of rotation toward the outer diameter side.

  In the cap 3 used conventionally as shown by the dotted line, the ocean current flows as indicated by the dotted arrow, and the direction thereof is small in angle with respect to the rotation axis and close to vertical.

  In the first embodiment, the cap 4 is provided instead of the cap 3 so that the ocean current collides with the cap 4 and is dispersed toward the outer peripheral side of the wing 2 as indicated by the solid arrow. And its orientation will have a greater angle with respect to the axis of rotation. The flow component in the vertical direction toward the rotation axis in the ocean current is lost as much as it collides with the cap 4. However, since sufficient energy to rotate the blade 2 is obtained, power generation is possible.

  And the direction component of the fish which has swam so that it may collide toward the center part of wing | blade 2 is also changed to the outer peripheral side by generating the direction component which distributes and flows toward the outer peripheral side of wing | blade 2. FIG. As a result, it is possible to reduce the probability of collision with the wing 2.

  The larger the diameter of the cap 4, the lower the probability that the fish will collide with the wing 2, but the larger the diameter, the more loss. Therefore, the diameter of the cap 4 (the length from the rotation center to the outer periphery formed by the rotation of the cap 4) is preferably set to 5% to 25% of the rotation diameter of the blade 2.

  As a modification of the first embodiment, even if the shape of the cap 14 is a simple conical shape (conical shape in which the generatrix is a substantially straight line) as shown in FIG. As indicated by the arrows, the wings 2 are dispersed toward the outer peripheral side, and the collision probability of fish can be reduced. The flow of the ocean current can be changed toward the outer peripheral side of the wing 2 with less resistance in the cap 4 shown in FIG. However, the simple conical cap 6 as shown in FIG. 2 is easy to manufacture and can reduce the cost.

(2) Embodiment 2
An ocean current power generation system according to Embodiment 2 of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as the said Embodiment 1, and the overlapping description is abbreviate | omitted.

  The second embodiment is configured such that the blade 12 is a swept blade with respect to the flow direction. In other words, the blade 12 has a shape in which the central portion near the rotation axis has an angle close to perpendicular to the rotation axis, but the angle gradually decreases toward the tip and retracts.

  In other words, the angle between the camber line connecting the midpoint between the upper surface and the lower surface in the cross section of the blade 12 and the rotation axis is gradually reduced toward the tip (the camber line is substantially U-shaped).

  As in the blades 2 in the first and second embodiments, the rotational energy obtained when the blades are installed perpendicular to the rotation axis is large. However, according to the third embodiment, the component flowing toward the outer peripheral side of the blade 12 is increased by using the blade 12 as a retracted blade in the flow direction. As a result, it is possible to greatly reduce the probability that the fish directly collides with the wing 12.

  Moreover, since the probability of fish colliding with the wing 12 is reduced by using the swept wing, the degree of damage to the wing 12 itself is reduced, and it is possible to extend the life and reduce the cost.

(3) Embodiment 3
An ocean current power generation system according to Embodiment 3 of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as the said Embodiment 1, and the overlapping description is abbreviate | omitted.

  In ocean current power generation systems, it is necessary to reduce the lethality of fish while not reducing the original power generation capacity of the power generation system. If the wing diameter is reduced, the probability of fish collision can be reduced, but the power generation capacity is reduced.

  Therefore, in the third embodiment, auxiliary wings are used so that the power generation capacity does not decrease while the blade diameter is kept small to reduce the collision probability of fish.

  As shown in FIG. 4, a cap 4 and a plurality of blades 2 similar to those in the first embodiment are provided, and a circular outer peripheral band ring 8 for connecting the blades 2 to each other is provided on the outer peripheral side of the blade 2. Further, an intermediate band ring 9 is provided concentrically on the inner diameter side of the outer peripheral band ring 8. A plurality of auxiliary wings 10 are provided radially between each of the wings 2 in the circumferential direction, and the auxiliary wings 10 are configured to be supported at both ends by an outer peripheral band ring 8 and an intermediate band ring 9, respectively. ing.

  According to the third embodiment, by installing the outer peripheral band ring 8 on the outer peripheral side of the blade 2, it is possible to reduce blade tip vortices generated at the tip portion of the blade 2. Fluctuations can be suppressed, thereby reducing the impact on downstream ecosystems.

  In addition to the wing 2, the auxiliary wing 10 can also work to convert the ocean current flow into rotational energy. For this reason, the blade diameter which requires a predetermined output can be made smaller than that of the power generation system without the auxiliary blade 10. As a result, the smaller the wing diameter, the lower the probability that the fish will collide with the wing, thereby reducing the impact on the ecosystem.

  Further, since the auxiliary wing 10 is supported by the outer peripheral band ring 8 and the intermediate band ring 9, the tip vortex generated by the auxiliary wing 10 is reduced similarly to the wing 2, and the flow fluctuation in the downstream area of the ocean current power generation system is reduced. Will be suppressed and the impact on the ecosystem will be reduced.

  As in the second embodiment, the third embodiment is applied even when the blade 2 is a swept blade with respect to the flow direction, and an outer peripheral band ring 8 is provided on the outer peripheral side of the blade 2, and an intermediate band ring 9 is provided. By providing the auxiliary wing 10 between the two, the effects of the second embodiment and the third embodiment can be obtained simultaneously.

  FIG. 5 shows a modification of the third embodiment. In this modification, the auxiliary wing 10 is provided in a state of being supported between the rotating shaft covered with the cap 4 and the intermediate band ring 9. Also in this case, similarly to the third embodiment shown in FIG. 4, the blade diameter of the wing 2 can be reduced to reduce the collision probability of the fish, and the necessary power generation can be ensured.

  However, since the configuration shown in FIG. 4 has a smaller number of wings and an area occupied by the wings in the cross section between the rotation shaft and the intermediate bundling 9 than the configuration shown in FIG. The probability of penetrating without colliding with the wing is high and the lethality can be lowered.

  On the other hand, according to the configuration shown in FIG. 5, the auxiliary wing 10 is provided so that both ends are connected between the rotating shaft and the intermediate bundling 9. It is considered that the strength is higher than the configuration in which 10 is connected between the intermediate bundling 9 and the outer peripheral bundling 8.

(4) Embodiment 4
An ocean current power generation system according to Embodiment 4 of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as the said Embodiment 1, and the overlapping description is abbreviate | omitted.

  The fourth embodiment corresponds to a seafloor fixed type ocean current power generation system, and the nacelle 1 is fixed to the seabed by a support 21. The nacelle 1 incorporates a seawater electrolyzer. The electric power generated by the generator built in the nacelle 1 is supplied to the seawater electrolysis apparatus, and the hydrogen generated by electrolysis of the seawater is stored as energy. And discharged from the bubble discharge hole 24 at the tip of the support 23 into the seawater as bubbles 25. The support column 23 is fixed to the seabed so that the bubble discharge hole 24 is positioned in front of the center of the rotating shaft covered with the cap 14.

  Here, the fourth embodiment includes any one of the configurations in the first to third embodiments and the respective modified examples.

  According to the fourth embodiment, oxygen generated by electrolyzing seawater is discharged from the bubble discharge hole 11 located in front of the center of the rotating shaft, so that oxygen is discharged from the upstream side of the blade 2. As a result, the bubbles 25 are evenly distributed over the rotational diameter of the blade 2, and an oxygen bubble film is formed in the vicinity of the leading edge of the blade 2. This bubble film can act as a cushioning material that cushions the impact of fish when they collide with the wing 2 to reduce the rate of death or injury or reduce the direct collision with the wing 2 itself.

  Further, the oxygen bubbles 25 that have passed through the wing 2 are diffused in the sea by the rotation of the wing 2 and flow downstream. Oxygen has an action of purifying water and an action of activating the activity of plankton living in the downstream area. As a result, downstream fishing grounds will be activated.

  As a modification of the fourth embodiment, a case where the fourth embodiment is applied to a mooring type ocean current power generation system will be described with reference to FIG. The nacelle 1 is supported by a structural member 31, and the structural member 31 is fixed to the seabed by an anchor 33 via a mooring wire 32. A conical cap 14 similar to the modification of the first embodiment is provided on the rotating shaft, and a T-shaped pipe 34 is attached to the tip of the rotating shaft so as to penetrate the cap 2. Is formed with a bubble discharge hole 35. The bubble discharge hole 24 is located in front of the center of the rotating shaft covered with the cap 14.

  As in the third embodiment, the nacelle 1 has a built-in seawater electrolyzer, and electric power is supplied from a generator built in the nacelle 1 to electrolyze the seawater, and hydrogen generated is stored as energy. At the same time, the generated oxygen is sent to the pipe 34 and discharged from the bubble discharge hole 35 into the seawater as bubbles 25.

  Oxygen generated by the electrolysis of seawater is discharged while rotating from the bubble discharge hole 35 located in front of the center of the rotating shaft, so that the bubbles 25 are spread over the rotating diameter of the blade 2 and the front of the blade 2 A film of oxygen bubbles is formed near the edge. By this bubble film, the impact when the fish collides with the wing 2 is relieved, the injury rate is reduced, and the collision with the wing 2 itself is reduced.

  Similarly to the third embodiment, the oxygen bubbles 25 are diffused in the sea by the rotation of the wings 2 and flow downstream, so that the oxygen purification action and the plankton activity in the downstream region are activated, Downstream fishing grounds are activated.

  FIG. 8 shows a modification of the configuration for discharging oxygen bubbles in the fourth embodiment. In this example, a bubble discharge hole 45 is directly formed at the center tip portion of the cap 44. Accordingly, oxygen generated from the seawater electrolyzer built in the nacelle 1 is discharged from the bubble discharge hole 45 of the cap 44.

  FIG. 9 shows another modification of the configuration for discharging oxygen bubbles in the fourth embodiment. In this example, a plurality of bubble discharge holes 55 are arranged in a circular shape in the peripheral region of the cap 54. In this case, the discharged bubbles are further diffused in the seawater with the rotation of the blade 2.

  In this manner, any number of bubble discharge holes provided in the cap can be formed in any region. When the bubble discharge hole is formed in the cap, if it is formed at the center portion in front of the rotating shaft as shown in FIG. 8, there is a possibility that the static pressure is high and it is difficult to discharge the bubbles. On the other hand, when the bubble discharge hole is formed in the peripheral region of the cap as shown in FIG. 9, the static pressure is lower and the bubble can be easily discharged.

  As in the modification shown in FIG. 10, a bubble discharge hole may be formed in the blade 62 instead of the cap 64. FIG. 11 shows an enlarged view of the shape of the wing 62, and FIG. 12 shows a longitudinal sectional shape along the line AA in FIG. The wing 62 has a hollow structure having a hollow inside, and a bubble discharge hole 63 is provided from the tip to the front edge region. Oxygen generated from the seawater electrolyzer built in the nacelle 1 is discharged from the rotating shaft through the internal space of the blade 62 into the sea through the bubble discharge hole 63 and diffused as the blade 62 rotates.

  These modified examples are examples relating to the configuration for discharging bubbles. The present invention is not limited to these modified examples, and the present embodiment can be used as long as the bubbles are discharged from the cap provided at the tip of the rotating shaft or from the front side of the cap. The effect similar to the form 4 of this can be show | played.

(5) Embodiment 5
An ocean current power generation system according to Embodiment 5 of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as the said Embodiment 1-4, and the overlapping description is abbreviate | omitted.

  In the fifth embodiment, as shown in FIG. 13, the rear end 1 a of the nacelle 1 has a conical shape with the end as the apex. Since the rear end portion 1 a of the nacelle 1 has such a conical shape, no dead water region is formed in the downstream region of the nacelle 1. For this reason, generation | occurrence | production of the cavitation in the downstream area of the nacelle 1 is suppressed, and the killing of the fish caused by cavitation is avoided.

  As a result, according to the fifth embodiment, it is possible to reduce the probability of killing fish in the downstream area of the ocean current power generation system.

(6) Embodiment 6
An ocean current power generation system according to Embodiment 6 of the present invention will be described with reference to FIGS. FIG. 14 shows a front view of the main engine shape of this ocean current power generation system, FIG. 15 shows the shapes of the cap 74 and the wing 2 as a left side view thereof, and FIG. 16 is taken along the line BB of the wing 2 in FIG. A cross-sectional shape is shown. In addition, the same code | symbol is attached | subjected to the same component as the said Embodiment 1-5, and the overlapping description is abbreviate | omitted.

  On the upstream side of the nacelle 1 and the wing 2, a conical cap 74 that is concave inward from the center of rotation toward the outer diameter measurement is provided. The cap 74 is further cut away so as to expose the wing 2. 74a is provided.

  In the case of a conventional shape such as the cap 106 shown in FIGS. 32 and 33, the flow direction of the ocean current is parallel along the rotation axis.

  On the other hand, in the same manner as in the first to fifth embodiments, the shape of the cap 74 in the sixth embodiment causes the ocean current to collide with the cap 74 and disperse in the outer circumferential direction of the wing 2 as indicated by the arrows. Is done.

  The ocean current component flowing in the vertical direction of the wing 2 is lost as a collision loss, but is sufficiently secured as energy for rotating the wing 2 and power generation is possible.

  Furthermore, according to the sixth embodiment, the notch 74a is formed in the cap 74 so that the blade 2 is exposed. As shown in FIG. 15, the notch 74 a exists so that a gap exists between the cap 74 and the blade 2. Further, as shown in FIG. 16, the entire surface including both the pressure surface 2 a and the negative pressure surface 2 b of the blade 2 is exposed by the notch 74 a of the cap 74. Thereby, an ocean current flows through the wing 2, and the performance as the wing can be sufficiently exhibited, and a decrease in output due to the cap 74 can be suppressed.

  As described above, according to the sixth embodiment, the advancing direction of the fish that have swam so as to collide with the center of the wing 2 is changed to the outer peripheral side by the cap 74, and the collision probability is reduced. Since the notch 74a is formed in the cap 74, it is possible to suppress a decrease in output due to the cap 74.

(7) Embodiment 7
An ocean current power generation system according to Embodiment 7 of the present invention will be described with reference to FIGS. FIG. 17 shows a front view of the main engine shape of this ocean current power generation system, FIG. 18 shows the shapes of the cap 84 and the wing 2 as a left side view thereof, and FIG. 19 shows the CC line of the wing 2 in FIG. A cross-sectional shape is shown. In addition, the same code | symbol is attached | subjected to the same component as the said Embodiment 1-6, and the overlapping description is abbreviate | omitted.

  In the sixth embodiment, the notch 74a of the cap 74 is formed so as to expose the entire surface including both the suction surface and the pressure surface of the blade 2. On the other hand, in the seventh embodiment, the notch 84a is formed in the cap 84 so that only the pressure surface of the blade 2 is exposed. More specifically, as shown in FIG. 18, only the pressure surface 2a of the blade 2 is notched so that there is a gap between the cap 84 and there is no gap between the suction surface 2b and the cap 84. 84a is formed. Further, as shown in FIG. 19, the pressure surface 2 a of the blade 2 is exposed by the notch 84 a of the cap 84.

  Thus, in the seventh embodiment, the exposed portion of the blade 2 due to the notch 84a is limited to the pressure surface 2a, but the blade 2 rotates due to the pressure difference between the pressure surface 2a and the suction surface 2b. It is possible to suppress a decrease in output due to the cap 84. In addition, since the cap 84 covers more wings 2 than in the sixth embodiment, it is possible to further reduce the rate of death and injury of fish.

(8) Embodiment 8
An ocean current power generation system according to Embodiment 8 of the present invention will be described with reference to FIGS. FIG. 20 shows a front view of the main machine shape of this ocean current power generation system, and FIG. 21 shows the shapes of the cap 94 and the blade 2 as a left side view thereof. The same components as those in the first to seventh embodiments are denoted by the same reference numerals, and redundant description is omitted.

  In the eighth embodiment, the wing 2 is joined onto the cap 94 or the wing 2 and the cap 94 are formed integrally. In the first to seventh embodiments, a cap is provided on the upstream side of the blade, and the shape of the blade is not formed at all on the cap. For this reason, the part covered with the cap is in a state where no wing exists.

  On the other hand, in the eighth embodiment, since the blade 2 is joined on the cap 94, the shape of the central portion of the blade is formed on the surface of the cap 94. As a result, the ocean current acts on a larger area of the wing 2 to increase the amount of work and increase the output.

  Also in the eighth embodiment, as in the first to seventh embodiments, the ocean current flows in the outer circumferential direction of the wing 2 due to the presence of the cap 94, so that it is possible to reduce the collision probability of fish.

(9) Embodiment 9
The ocean current power generation system according to Embodiment 9 of the present invention will be described with reference to FIG. 22 showing main components and FIG. 23 showing the shapes of the wings and caps. The same components as those in the first to eighth embodiments are denoted by the same reference numerals, and redundant description is omitted.

  In the ninth embodiment, the cap 104a is provided so that the center position on the figure of the cap 104a is eccentric with respect to the rotation axis center of the blade 2. By decentering the center position of the cap 104a on the figure, the radius at which the cap 104a rotates is apparently increased as indicated by the one-dot chain line in FIG. Thereby, the area where the cap 104a covers the upper wing 2 apparently increases, and the death / injury rate of fish can be reduced.

  Further, since the area of the cap 104a itself is smaller than the apparent area surrounded by the alternate long and short dash line that covers the wing 2, the area where the wing 2 is exposed from the cap 104a and receives the ocean current is also secured and covered with the cap 104a. The output fall by this can be suppressed.

  A gear or the like may be provided between the rotation shaft of the cap 104 and the rotation shaft of the blade 2 so that the rotation speed of the cap 104 and the rotation speed of the blade 2 are different. In this case, it is possible to always change the portion where the wing 2 is hidden by the cap 104 with respect to the ocean current. Of the plurality of blades 2, the larger the exposed area, the larger the load that receives the ocean current. However, this load can be made uniform, the fatigue of the entire blade 2 can be dispersed, and the life can be extended. In addition, the load applied to the rotating shaft of the generator is made uniform, so that it can be prevented from being reduced. It should be noted that the uniform load on the blade 2 is more effective when the rotational speed of the cap 104 is higher than the rotational speed of the blade 2.

  FIG. 24 shows main components in the ocean current power generation system according to the first modification of the ninth embodiment, and FIG. 25 shows the shapes of the blade 2 and the cap 104b.

  In the first modified example, unlike the ninth embodiment, the center of the rotational axis of the blade 2 and the center of the cap 104b on the figure coincide with each other and are not eccentric. Further, as shown in FIG. 25, the cap 104b is not a perfect circle as in the ninth embodiment, but has a shape in which a part of the hatched region 104c is missing.

  According to the first modification, the radius at which the cap 114 rotates is apparently increased as shown by the alternate long and short dash line in FIG. 25, and the fish death rate can be reduced as in the ninth embodiment. it can. Further, since the cap 114 has a shape in which a part of the region 104c is missing from the perfect circle, the portion where the blade 2 is exposed from the cap 2 is larger than that in the ninth embodiment having the circular cap 104, and the output is increased. Can be improved.

  FIG. 26 shows the shapes of the blade 2 and the cap 114 in the ocean current power generation system according to the second modification of the ninth embodiment.

  In this second modification, the center of rotation of the blade 2 and the center of the cap 114 on the figure are not coincident and are eccentric. Furthermore, the cap 114 has an elliptical shape.

  According to the second modification, the radius at which the cap 114 rotates apparently increases as shown by the dotted line in FIG. 23, and the fish death rate is similar to the ninth embodiment and the first modification. Can be reduced. Further, by making the cap 114 oval, the portion where the wing 2 is exposed from the cap 2 and receives the ocean current is larger than in the ninth embodiment having the circular cap 104, and the output can be improved. .

  FIG. 27 shows the blade 2 and the cap 124 in the ocean current power generation system according to the third modification of the ninth embodiment. In the third modified example, the center of the rotational axis of the blade 2 and the center of the cap 124 on the figure coincide with each other and are not eccentric, and the cap 124 has a polygonal shape.

  Here, the number of the wings 2 is 3, and the cap 124 has a triangular shape as a polygonal shape so as to have the same number of vertices. Further, the three apexes of the cap 124 are provided so as to be positioned between the wings 2. When the number of the wings 2 is four, the cap is a quadrangle, and when the number of the wings 2 is five, the cap has a pentagonal shape, and each apex is preferably located between the wings.

  FIG. 28 shows a cross section taken along line DD of the cap 124 in FIG. As shown in FIG. 28 (a), the shape may be such that a part 124a of a cross section of a symmetrical isosceles triangle is removed, or a shape in which the left and right are not targeted as shown in FIG. 28 (b). It may have a shape with a part 124b missing.

  According to the third modification, the radius of rotation of the cap 124 is apparently increased as shown by the alternate long and short dash line in FIG. 27. Therefore, the ninth embodiment, the first modification, and the second modification are described. Similar to the example, the death rate of fish can be reduced. Furthermore, since the cap 124 has a polygonal shape, the portion where the wing 2 is exposed from the cap 2 is larger than in the ninth embodiment having the circular cap 104, and the output is improved.

  In the first, second, and third modified examples, as in the ninth embodiment, a gear or the like is provided between the rotating shafts of the caps 114a, 114b, and 124 and the rotating shaft of the blade 2, and the cap 114a, The rotational speeds of 114b and 124 may be different from the rotational speed of the blade 2.

(10) Embodiment 10
An ocean current power generation system according to Embodiment 10 of the present invention will be described with reference to FIGS. FIG. 29 shows a front view of the main machine shape of this ocean current power generation system, and FIG. 30 shows the shapes of the cap 134 and the blade 2 as a left side view thereof. The same components as those in the first to ninth embodiments are denoted by the same reference numerals, and redundant description is omitted.

  In the tenth embodiment, an annular net 41 is provided on the surface of the cap 134. The portion of the wing 2 exposed from the cap 134 rotates by receiving a sea current, but the probability that the fish collides with the wing 2 is not zero at all.

  Therefore, in the tenth embodiment, by providing the net 41 on the upstream side of the wing 2, it is possible to avoid the fish from colliding with the wing 2 and to reduce the lethality of the fish.

  By the way, when the net 41 is installed on the upstream side of the wing 2, seagrass, flowing dust, and the like adhere to the net 41, and thus a work for removing it is necessary. According to the tenth embodiment, when the net 41 rotates together with the cap 134, the number of operations to be removed can be reduced by shaking off dust once attached.

  FIG. 31 shows a configuration of an ocean current power generation system according to a modification of the tenth embodiment of the present invention. In this modification, in order to install the net 41 further upstream than the cap 144, a net support bar 42 is provided on the upstream side of the cap 144, and the net 41 is attached to the net support bar 42. The net support bar 42 rotates together with the cap 144, and the net 41 rotates accordingly.

  In this modified example, as in the tenth embodiment, the fish does not collide with the wing 2 to reduce the lethality of the fish, and the dust once attached is swung away by the rotation of the net 41. The number of operations to be removed can be reduced.

  The net 41 can be manufactured using a material such as metal, chemical fiber, or resin. When metal is used, the rotational resistance of the net 41 in the ocean current can be reduced. When chemical fiber is used, the effect that it is hard to damage a fish by bending along an ocean current is acquired. Further, when a resin is used, it is possible to reduce the rotational resistance and reduce the damage to fish.

  According to the first to tenth embodiments, it is possible to provide a ocean current power generation system that reduces the mortality rate due to a fish collision and has little influence on the environment, such as the decline of the predator due to the fish death.

  The above embodiments are merely examples and are not limited, and various modifications can be made.

  Each of the above-described Embodiments 2 to 10 and the respective modifications includes a cap having the same shape as that of Embodiment 1 above. However, even if such a cap is not provided, the collision probability of fish can be reduced. For example, by having a swept wing in the second embodiment and its modification, the collision probability of fish can be reduced and the impact on the ecosystem can be reduced without having the same cap as in the first embodiment. it can. In addition, by generating bubbles in the third and fourth embodiments and the respective modifications, it is possible to reduce the collision probability of fish and the impact on the ecosystem without having the same cap as in the first embodiment. Is possible.

  Moreover, in the said Embodiment 4 and each modification of Embodiment 4, the seawater electrolyzer does not necessarily need to be incorporated in the nacelle and may be provided outside the nacelle.

  Furthermore, although the rear end of the nacelle has a conical shape in the fifth embodiment, the rear end of the nacelle similarly has a conical shape in each of the sixth to tenth embodiments and the modified examples. May be.

  Alternatively, in the tenth embodiment and its modifications, the cap may be provided with a notch as in the sixth and seventh embodiments, or the wing is joined to the cap as in the eighth embodiment. Alternatively, it may be integrally formed.

1 Nacelle 2, 12, 62 Wings 4, 14, 44, 54, 64, 74, 84, 94, 104a, 104b, 114, 124, 134, 144 Cap 8 Outer band ring 9 Intermediate band ring 10 Auxiliary blades 21, 23 Post 22 Cable 24, 35, 45, 55 Bubble discharge hole 34 Pipe 41 Net 42 Net support rod

Claims (21)

A wing that converts the flow of seawater into rotational energy;
The converted rotational energy is supplied through a rotating shaft connected to the wing to generate electric power, and a generator enclosed in a nacelle;
In the ocean current power generation system comprising
A cap provided so as to cover a predetermined region from the rotation center connected to the rotation shaft in the blade to the outer diameter side;
An ocean current power generation system, wherein the cap has a conical shape.   2. The ocean current power generation system according to claim 1, wherein the cap has a conical shape that is concave inwardly toward the outer diameter side from the center of rotation or a conical shape in which a bus bar is a substantially linear shape. Item 1. An ocean current power generation system according to item 1.   The ocean current power generation system according to claim 1, wherein the wing has a receding wing shape that recedes with respect to a flow direction of seawater. A circular outer peripheral bundling connecting the wing to the outer peripheral side of the wing;
An intermediate bundling provided concentrically with the outer peripheral band ring on the inner peripheral side of the outer peripheral band ring;
An auxiliary wing provided radially from the rotating shaft toward the intermediate bundling;
The ocean current power generation system according to any one of claims 1 to 3, further comprising: A circular outer peripheral bundling connecting the wing to the outer peripheral side of the wing;
An intermediate bundling provided concentrically with the outer peripheral band ring on the inner peripheral side of the outer peripheral band ring;
Ailerons provided radially from the intermediate bundling toward the outer peripheral bundling;
The ocean current power generation system according to any one of claims 1 to 3, further comprising: Seawater electrolysis apparatus for electrolyzing seawater using the power generated by the generator to generate oxygen and hydrogen;
A bubble discharge means having a bubble discharge hole that is supplied with oxygen generated by the seawater electrolyzer and discharges bubbles from the upstream side of the blade,
The ocean current power generation system according to any one of claims 1 to 5, further comprising:   The bubble discharging means has a support column having the bubble discharging hole at one end, and is supplied with oxygen generated by the seawater electrolyzer to discharge bubbles from the bubble discharging hole. Ocean current power generation system.   The bubble discharging means includes a pipe connected to the rotating shaft through the cap and extending toward the upstream side of the blade, having the bubble discharging hole at one end, and rotating with the rotation of the rotating shaft. The ocean current power generation system according to claim 6, wherein the seawater electrolysis apparatus is supplied with oxygen and discharges bubbles from the bubble discharge hole. Seawater electrolysis apparatus for electrolyzing seawater using the power generated by the generator to generate oxygen and hydrogen;
Bubble discharge means having a bubble discharge hole for discharging bubbles by being supplied with oxygen generated by the seawater electrolyzer,
Further comprising
The said cap has the said bubble discharge hole as said bubble discharge means, The oxygen which the said seawater electrolysis apparatus gave is given, and it discharges | emits from the said bubble discharge hole. The ocean current power generation system described in 1. Seawater electrolysis apparatus for electrolyzing seawater using the power generated by the generator to generate oxygen and hydrogen;
Bubble discharge means having a bubble discharge hole for discharging bubbles by being supplied with oxygen generated by the seawater electrolyzer,
Further comprising
As the bubble discharge means, the wing has a hollow structure in which the bubble discharge hole is formed along the edge, and is supplied with oxygen generated by the seawater electrolyzer and discharges the bubble from the bubble discharge hole. The ocean current power generation system according to any one of claims 1 to 5, wherein   6. The ocean current power generation system according to claim 1, wherein a rear end portion of the nacelle has a conical shape having a rear end as an apex.   The ocean current power generation system according to claim 1, wherein the cap is provided with a cutout so that the wing is exposed.   The ocean current power generation system according to claim 1, wherein the cap is provided with a notch so that only the pressure surface of the wing is exposed.   2. The ocean current power generation system according to claim 1, wherein the wing is joined to the cap in the predetermined region or formed so as to be integrated with the cap.   The ocean current power generation system according to claim 1, wherein a center of the cap on the figure is eccentric from the rotation axis.   12. The cap according to claim 1, wherein the cap has a shape in which a part of a region is removed from a perfect circle, and a part of the wing is exposed from the region. Ocean current power generation system.   The ocean current power generation system according to claim 1, wherein the cap has an elliptical shape, and a center of the ellipse is decentered from the rotation axis.   12. The cap according to claim 1, wherein the cap has the same number of polygonal shapes as the wings, and each vertex of the polygon is located between the wings. Ocean current power generation system.   The ocean current power generation system according to any one of claims 15 to 18, wherein the rotation speed of the wing and the rotation speed of the cap are different.   The ocean current power transmission system according to any one of claims 1 to 5 or 11, wherein a net is further provided on the cap, and the net rotates together with the cap.   6. The apparatus according to claim 1, further comprising: a member joined so as to extend in an upstream direction from a tip of the cap; and a net attached to the member, wherein the net rotates together with the cap. Or the ocean current power generation system according to any one of 11;

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