JP2014005766A - Water flow generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve power generation efficiency by effectively utilizing a water flow.SOLUTION: A water flow power generation device in an embodiment comprises a rotary shaft, a vane, a housing, and a water flow induction section. The rotary shaft transmits power to a power generator side. The vane is integrally fixed to the rotary shaft on a base end side, and rotates together with the rotary shaft under the water flow. A power generator is built in the housing, and the housing is provided on an upper stream side of the water flow than the vane. The water flow induction section is constituted by an outline portion of the housing, and induces the water flow received by the housing toward a tip side of the vane so that the water flow is radially spread.

Description

  Embodiments described herein relate generally to a water current power generation apparatus.

  There are many types of power generation systems that use water as power, such as power generation by water turbines using height differences such as dams, power generation using ocean wave power, tides, and power generation using osmotic membranes and temperature differences. Among them, a power generation system that can easily obtain large-capacity energy is a power generation system that uses a flow of seawater such as a tidal current or a sea current other than a power generation system that uses a difference in elevation.

  However, tidal current power generation systems and ocean current power generation systems that use the flow of seawater leave room for improvement with regard to large-capacity machines, and are being developed ahead of other parts of Europe.

  By the way, a propeller-type ocean current (or tidal current) power generation device generates power by converting kinetic energy of ocean current into rotational energy via a wing and driving a generator with this rotational energy. Therefore, the ocean current power generation device can obtain a corresponding power generation amount by increasing the blade rotation speed or blade diameter. Further, it is possible to extract more energy for power generation by improving the performance of the blade itself.

  However, although several existing techniques for improving the performance and efficiency of the wing have already been proposed, the mechanism tends to be complicated. On the other hand, an increase in the number of rotations of the wing facilitates the so-called cavitation, and the generation of wing tip vortices becomes prominent, which may adversely affect the wing itself and the marine ecosystem around the wing. In addition, the increase in the wing diameter is concerned about contact between the wing and the ship and contact between the wing and the seabed. For this reason, the design which increases a blade diameter exceeding a predetermined dimension has become difficult.

Japanese Patent No. 4535378 US Pat. No. 7,830,033 US Pat. No. 7,948,107 Japanese Patent No. 4001485 US Patent Application Publication No. 2011/0081251 US Pat. No. 6,091,161

  Therefore, it is necessary to consider a blade shape that obtains high output without increasing the blade rotation speed and blade diameter. For example, when it is assumed that a blade normally used in a windmill is applied as a blade for ocean current power generation, a design in which the blade cord length is increased due to the difference in the density of the working fluid and the Reynolds number is necessary. This makes it possible to reduce the peripheral speed ratio in the sea by increasing the cord length of the wind turbine blade, thereby enabling the blade to rotate at a predetermined rated speed in the sea. However, for the reasons described above, it is difficult to directly apply wind turbine blades as ocean current power generation blades.

  In view of such circumstances, a problem to be solved by the present invention is to provide a water current power generation apparatus that can increase the efficiency of power generation by effectively utilizing a water flow.

  The water current generator according to the embodiment includes a rotating shaft, a wing, a casing, and a water flow guide. The rotating shaft transmits power to the generator side. The blade is integrally fixed on the base end side with respect to the rotation shaft, and receives the water flow and rotates together with the rotation shaft. The housing has a built-in generator and is provided upstream of the water flow from the wing. The water flow guiding portion is configured by an outer portion of the casing, and guides the water flow received by the casing in the radial direction so as to spread radially.

The figure which shows the structure of the water flow electric power generating apparatus which concerns on 1st Embodiment. The figure which shows the structure of the water-flow power generator of FIG. 1 more concretely. The figure which shows the structure of the water-flow electric power generating apparatus of a comparative example. The figure which shows the structure of the other water current power generator from which the structure of a nacelle differs from the water current power generator of FIG. The figure which shows the structure of the other water current power generator from which the structure of the boss | hub and its periphery differs from the water current power generator of FIG. The figure which shows the structure of the water flow electric power generating apparatus which concerns on 2nd Embodiment. The figure for demonstrating the water flow which arises in the vicinity of a wing | blade in the water current power generator of the comparative example shown in FIG. The figure which shows the structure of the other water current power generator from which the structure of a nacelle differs from the water current power generator of FIG. The figure which shows the structure of the water flow electric power generating apparatus which concerns on 3rd Embodiment. The figure which shows the structure of the other water current power generator from which the structure of a wing | blade differs from the water current power generator of FIG. The figure which shows the structure of the water flow electric power generating apparatus which concerns on 4th Embodiment.

Hereinafter, embodiments will be described with reference to the drawings.
[First Embodiment]
As shown in FIG. 1, for example, the water current generators 10 and 20 of the present embodiment used as a pair are propeller type ocean current power generation (or tidal current power generation) systems installed in the sea 16. The water current generators 10 and 20 are connected to each other by a connecting member 12 and are anchored (moored) to a seabed 15 having a depth of 200 m or more via a mooring rope 14.

  As shown in FIGS. 1 and 2, the pair of water current generators 10, 20 includes a nacelle 2 as a housing, a plurality of blades 3, and a boss 5 that supports the blades 3. The nacelle 2, the boss 5, and the wing 3 are configured using a material having high corrosion resistance against seawater or a material coated with a paint having high corrosion resistance.

  The nacelle 2 has a watertight structure, and as shown in FIG. 2, a generator 8, a transmission mechanism 7b, and the like are incorporated (accommodated). The nacelle 2 has a predetermined buoyancy. Here, the pair of water current generators 10 and 20 is statically secured with respect to each other when the blades 3 included in the pair rotate in the opposite direction and generate equivalent thrust.

  As shown in FIG. 2, the boss 5 has a function as a support portion that supports the base end side of the wing 3. The boss 5 has a watertight structure like the nacelle 2, and incorporates the rotating shaft 7 in cooperation with the nacelle 2. One end portion side of the rotating shaft 7 is connected to the speed change mechanism 7b in the nacelle 2, and the other end portion side of the rotating shaft 7 is fixed to the boss 5 body via the hub 7a. That is, the wing 3 is integrally fixed to the rotary shaft 7 at the base end side via the boss 5 (hub 7a), and when the wing 3 body receives a water flow, it is integrated with the rotary shaft 7 (boss 5). And rotate.

  The power (driving force) of the rotating shaft 7 is transmitted to the generator 8 in the nacelle 2. Specifically, the rotation of the rotating shaft 7 is decelerated or increased by the speed change mechanism 7 b and is transmitted to the generator 8 via the transmission shaft 7 c between the speed change mechanism 7 b and the generator 8.

  For example, two or three blades 3 are provided for each of the water current generators 10 and 20. For example, when there are three blades 3, the individual blades 3 are respectively fixed at 120 ° intervals around the axis of the boss 5 (rotating shaft 7) on the base end side. In addition, each blade 3 has a shape in which each of the pressure surface (pressure surface) and the suction surface are aligned in a certain direction so that the rotational force of the rotation shaft 7 rotating in a certain direction can be obtained from each of the blades 3. Is formed.

  As shown in FIG. 2, each blade 3 configured in this manner converts kinetic energy obtained from the water current (sea current) F <b> 1 into rotational energy. On the other hand, the rotating shaft 7 that rotates together with the blades 3 transmits the converted rotational energy to the generator 8 in the nacelle 2 via the transmission mechanism 7b and the transmission shaft 7c. Electricity is generated using rotational energy.

  Next, a characteristic configuration of the nacelle 2 will be described. As shown in FIG. 2, the nacelle 2 is provided upstream of the wing 3 in the ocean current F <b> 1. The nacelle 2 is formed in a substantially conical shape and is arranged coaxially with the rotating shaft 7. The nacelle 2 includes a water flow receiving portion 2a and a water flow guiding portion 2b that are configured by the outer shape portion of the nacelle 2 body. As shown in FIG. 2, the water flow receiving portion 2 a is provided on the most upstream side of the ocean current F <b> 1 in the nacelle 2 body, and constitutes the substantially conical apex portion described above. The surface of the water flow receiving portion 2a is formed in a spherical shape.

  On the other hand, as shown in FIG. 2, the water flow guiding portion 2 b is configured by the substantially conical side portion described above. More specifically, the water flow guiding portion 2b is configured in a shape in which the outer peripheral length of the outer portion of the nacelle 2 increases from the upstream side to the downstream side of the water flow F1. In other words, the water flow guiding portion 2b is configured so that the water flow F1 received by the water flow receiving portion 2a of the nacelle 2 main body is radially spread (distributed radially) in the tip side direction of each blade 3 (the tip portion side direction of the blade). ).

  More specifically, when the force for rotating the blade 3 is to be increased, considering the moment (torque) of the force around the axis of the rotary shaft 7, as shown in FIG. It is more effective for improving the rotational force of the blade 3 to guide the water flow F2 to the tip side of the blade 3 than to the base end side). Therefore, in the water current generators 10 and 20 according to the present embodiment, the water flow guide portions 2b that radially expand the water flows F1 and F2 and guide the blades 3 toward the tip side of the wing 3 are provided in the nacelle 2, thereby enabling rotational energy for power generation. Can be taken out more efficiently.

  Here, the nacelle 100 of the comparative example will be described with reference to FIG. The nacelle 100 of the comparative example includes a columnar nacelle 92 configured such that a boss 95 that rotates integrally with the blade 3 is sandwiched between an upstream nacelle portion 92a and a downstream nacelle portion 92b. That is, the cylindrical nacelle 92 is configured such that the outer peripheral length of the outer shape portion of the nacelle 2 main body is equal on both the upstream side and the downstream side of the water flow F1. Therefore, as shown in FIG. 3, in the nacelle 100 of the comparative example, the water flow F <b> 3 does not spread radially but is guided to the base end side of the blade 3 as it is. For this reason, it is difficult for the nacelle 100 of the comparative example to improve the rotational force of the blade 3 from the viewpoint of the moment of force described above.

  On the other hand, in the water current generators 10 and 20 of the present embodiment, as shown in FIG. In this way, the fluid force can effectively act on the blade 3 to increase the rotational force of the blade 3. Therefore, according to the water current generators 10 and 20 of the present embodiment, the efficiency of power generation can be increased by effectively utilizing the water current (ocean current) F1.

  Moreover, it replaces with the nacelle 2 with which the water current electric power generators 10 and 20 are provided, and as shown in FIG. . As shown in FIG. 4, the outer portion of the nacelle 32 in the water current generator 30 is divided into an upstream outer portion 32c arranged on the upstream side of the water flow F1 and a downstream outer portion 32d arranged on the downstream side of the water flow F1. It is divided.

  The upstream outer shape portion 32c is formed in a columnar shape. On the other hand, the downstream outer shape portion 32d is formed in a shape that expands toward the downstream side from the upstream side of the water flows F1 and F5. The water flow guiding portion 32b included in the nacelle 32 is configured by such a downstream outer shape portion 32d. In other words, the ratio of the outer peripheral length increasing in the water flow guiding portion 32b increases from the upstream side to the downstream side of the water flows F1 and F5.

  Therefore, also in the water current power generation apparatus 30, as shown in FIG. 4, the water flow F5 is guided in the tip side direction of the blade 3 by the water flow guide portion 32b of the diverging nacelle 32. It becomes possible to increase and improve the efficiency of power generation.

  Note that the structure of the boss positioned downstream of the water flows F1 and F5 from the blade 3 is not particularly restricted in improving the power generation efficiency. Therefore, the boss 5 shown in FIG. As shown, the water current generator 40 divided into the boss 15 that rotates integrally with the blade 3 and the downstream nacelle portion 9 that does not rotate may be configured.

[Second Embodiment]
Next, a second embodiment will be described with reference to FIGS. In these drawings, the same components as those in the first embodiment shown in FIGS. 1 to 5 are denoted by the same reference numerals and redundant description is omitted.

  In this embodiment, as in the first embodiment, for example, a pair of water current generators 50 shown in FIG. The hydroelectric power generation device 50 includes wings 53 as shown in FIG. 6 instead of the wings 3 of the hydroelectric power generation devices 10 and 20 of the first embodiment shown in FIGS.

  For example, two or three blades 53 are provided for each water current generator 50. As shown in FIG. 6, each blade 53 is configured in such a shape that the tip side (wing tip side) is located downstream of the water flow F <b> 1 rather than the hub 7 a side (blade base end side). .

  Here, as shown in FIG. 7, in the hydroelectric power generation device 100 of the comparative example described above including the cylindrical nacelle 92, the water flow F <b> 3 that linearly travels along the cylindrical outer portion of the nacelle 92 is the surface of the blade 3. Then, a local water flow (turbulent flow) F7 that suddenly changes its direction in the radial direction (peripheral direction) of the blade 3 substantially perpendicular to this direction is generated.

  This local water flow F7 is generated by the blade 3 acting like a closing plate. In this case, a loss of fluid energy is caused by a local flow that rapidly changes the traveling direction. Further, the local water flow F7 is generated from the radial base end side (hub 7a side) of the blade 3, and becomes a turbulent flow that increases toward the tip end side (tip side) of the blade 3.

  Therefore, as shown in FIG. 6, the water current power generation apparatus 50 according to the present embodiment is configured so that the blade 53 is a retracted blade whose distal end side is located on the downstream side of the water flow F <b> 1 rather than the proximal end side. This suppresses sudden changes in the direction of water flow and suppresses the occurrence of turbulent flow. Therefore, according to the water flow power generation device 50, the water flow guiding portion 2b that radially expands the water flow is provided in the nacelle 2 and the blades 53 are the swept blades. In addition to the effects of the first embodiment, The loss of fluid energy can be reduced, which makes it possible to effectively generate torque in the blade 53.

  Further, in place of the nacelle 2 provided in the water current power generation apparatus 50, as shown in FIG. 8, the same effect as the water current power generation apparatus 50 can be expected by the water current power generation apparatus 60 provided with the nacelle 32 having a divergent shape as described above.

[Third Embodiment]
Next, a third embodiment will be described with reference to FIGS. 9 and 10, the same constituent elements as those in the first embodiment shown in FIGS. 1 to 5 are given the same reference numerals and redundant description is omitted. FIGS. 9 and 10 are views of water current generators 70 and 80, which will be described later, as viewed from the upstream side of the water current (sea current).

  In this embodiment, as in the first embodiment, for example, a pair of water current generators 70 shown in FIG. This hydroelectric power generation device 70 includes wings 73 as shown in FIG. 9 instead of the wings 3 of the hydroelectric power generation devices 10 and 20 of the first embodiment shown in FIGS.

  For example, two or three blades 73 are provided for each water current generator 70. As shown in FIG. 9, the central portion 73 a bulges in the lengthwise central portion 73 a from the base end side to the tip end side of each wing 73 in a direction opposite to the rotation direction R of the wing 73. Thus, a skew angle is given.

  As a result, in the water current power generation apparatus 70, as shown in FIG. 9, the traveling direction of the turbulent flow F9 that can be generated on the radial base end side (hub 7a side) of the blade 73 is rapidly changed. Propagation of the water flow F7) to the tip end side (tip side) of the blade 73 can be suppressed by providing the skew angle.

  Therefore, in the water current generator 70 of this embodiment, the blade 73 can effectively generate torque by suppressing the loss of fluid energy in the vicinity of the blade (increase in the turbulent flow F9). That is, according to the water current power generation apparatus 70, the efficiency of power generation can be increased by effectively utilizing the water current (sea current) by improving the performance and efficiency of the blades 73.

  Further, in place of the wing 73 provided in the water current power generation apparatus 70, a water flow power generation apparatus 80 provided with the wing 83 as shown in FIG. As shown in FIG. 10, the tip of the blade 83 of the hydroelectric power generation device 80 is arranged such that the tip end side (tip side) is closer to the rotation direction R side of the blade 83 than the base end side (hub side). A skew angle is given so as to be moved backward.

  Accordingly, also in the water current power generation device 80, as shown in FIG. 10, the turbulent flow F10 that can occur on the proximal end side in the radial direction of the blade 83 is given the skew angle, so that the tip portion of the blade 83 is provided. Propagation to the side can be suppressed, and high performance and high efficiency of the blade 83 can be achieved. Of course, the configuration of the blades 73 and 83 of the present embodiment may be added to the configuration of the blades of the water current generator illustrated in FIGS. 2, 4, 5, 6, and 8.

[Fourth Embodiment]
Next, a fourth embodiment will be described with reference to FIG. In FIG. 11, the same constituent elements as those in the first embodiment shown in FIGS. 1 to 5 are given the same reference numerals and redundant description is omitted.

  In this embodiment, as in the first embodiment, for example, a pair of water current generators 90 shown in FIG. This hydroelectric generator 90 includes wings 93 as shown in FIG. 11 instead of the wings 3 of the hydroelectric generators 10 and 20 of the first embodiment shown in FIGS.

  For example, two or three blades 93 are provided for each water current generator 90. As shown in FIG. 11, the individual blades 93 are configured such that the tip side (wing tip side) is located upstream of the water flow F1 with respect to the hub 7a side (blade base end side). .

  In other words, the water current generator 90 includes the nacelle 2 that guides the water flows F1 and F2 to the tip side, which is advantageous in generating torque in the blade 93, and the blades so as to receive the guided water flows F1 and F2. Since the tip side of 93 is moving forward, it is not directly affected by local turbulence (water flow F11) generated from the hub side and directed to the tip side described in the second and third embodiments. It is possible to efficiently convert the guided water streams F1 and F2 into rotational energy. Thereby, the kinetic energy of water flow F1, F2 can be taken in efficiently, without increasing the rotation speed and blade diameter of a blade, for example.

  Therefore, according to the water current power generation apparatus 90 of the present embodiment, the efficiency of power generation can be increased by effectively utilizing the water currents (ocean currents) F1 and F2. In addition, you may add the structure of the wing | blade 93 of this embodiment to the structure of the wing | blade of the water current power generator illustrated in FIG.2, FIG.4, FIG.5, FIG.9 and FIG.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  For example, in the first to fourth embodiments, power generation using the flow of seawater, such as ocean current power generation and tidal current power generation, has been exemplified. However, as long as the water current can be obtained from a direction orthogonal to the water depth direction. The hydroelectric generators of the first to fourth embodiments can be applied even in water other than the sea, such as a river.

  10, 20, 30, 40, 50, 60, 70, 80, 90 ... water current generator, 2, 32 ... nacelle, 2b, 32b ... water flow guide, 3, 53, 73, 83, 93 ... wings, 5, DESCRIPTION OF SYMBOLS 15 ... Boss, 7 ... Rotating shaft, 7a ... Hub, 7c ... Transmission shaft, 8 ... Generator, 32c ... Upstream external part, 32d ... Downstream outer diameter part, 9 ... Downstream nacelle, 73a ... Central part of wing | blade F1, water current (ocean current), F2, F5 water current.

Claims (8)

A rotating shaft that transmits power to the generator side;
A wing that is integrally fixed to the rotating shaft with respect to the rotating shaft, rotates with the rotating shaft under a water flow;
A housing containing the generator and provided on the upstream side of the water flow from the wing;
A water flow guiding portion that is configured by an outer portion of the housing and guides the water flow received in the housing in a radial direction so as to spread radially;
A water current generator comprising: The water flow guide portion is configured in a shape in which the outer peripheral length of the outer portion of the housing increases from the upstream side to the downstream side of the water flow.
The water current power generator according to claim 1. The ratio of the outer peripheral length increasing in the water flow guide portion increases from the upstream side to the downstream side of the water flow,
The water current generator according to claim 2. The outer shape portion of the housing is divided into an upstream outer shape portion arranged on the upstream side of the water flow and a downstream outer shape portion arranged on the downstream side of the water flow,
The water flow guiding portion is configured by the downstream outer shape portion,
The water current generator according to any one of claims 1 to 3. The wing is configured in such a shape that the tip end side is located on the downstream side of the water flow from the base end side.
The water current power generator according to any one of claims 1 to 4. The wing is configured in such a shape that the tip end side is located on the upstream side of the water flow than the base end side.
The water current power generator according to any one of claims 1 to 4. A skew angle is given to the central portion in the length direction of the wing so as to bulge the central portion in a direction opposite to the rotation direction of the wing.
The water current generator according to any one of claims 1 to 6. The entire wing is provided with a skew angle so that the tip side is more receded in the direction of rotation of the wing than the base end side of the wing.
The water current generator according to any one of claims 1 to 6.

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