JP2023082735A - Wave energy recovery system for ship, ship, and ship wave reduction method etc. of ship - Google Patents

Abstract

To use a system which may be mounted on a ship 1 to reduce wave energy of ship waves Aw occurring from a hull submerged part 2 during navigation of the ship 1.SOLUTION: A wave energy recovery device 20, which is disposed spaced apart from or contacting with a surface of a full body of a ship 1 at both broadside or the rear of the ship 1 at least when the ship 1 travels in a forward direction X, utilizes ship waves Aw generated at a hull submerged part 2 of the ship 1 to rotate a water turbine 21 and covert the rotation into electric energy with a power generator 23. Through the process, the wave energy recovery device 20 recovers part of wave energy of the ship waves Aw.SELECTED DRAWING: Figure 1

Description

The present invention reduces tow waves generated by a ship by recovering the wave energy of the tow waves with a wave energy recovery device located on the side of the ship and spaced from the hull surface. , wave energy recovery systems for ships, ships and methods for reducing tow waves for ships, and the like.

In a ship sailing on water, the hull affects the water surface (free surface) when moving, and waves are generated mainly from the bow, front shoulder, rear shoulder, stern, etc. of the hull. These waves include local waves (breaking waves, free surface shock waves, etc.) that move with the ship, and free waves that propagate to the sides and rear of the ship.

The free wave generated by this ship is called a "tug wave" (also written as "tug wave", "undertow", or "undertow") and is closely related to the wave-making resistance of the ship. In addition, when a ship is navigating narrow waterways such as harbors and canals, this tug wave is a sudden wave that strikes other ships underway or ships at anchor, especially small ships such as fishing boats and fishing boats. becomes. These tow waves induce a large sway in these small vessels, which may lead to dangerous situations such as flooding and capsizing. In addition, waves crashing against shellfish and fish farming facilities (aquaculture cages, etc.), coasts, quay walls, etc., also damage these facilities.

One of the countermeasures against this tow wave is to slow down the navigation speed of the ship itself. there is

In addition, there are many countermeasures against stern waves as countermeasures for reducing tow waves on the ship side in the prior art. For example, at the stern of the hull, a wave suppressing plate is provided so that it can move up and down so that it can move to a position that suppresses the top of the wave, or the tip of this wave suppressing plate is formed in a sawtooth shape so as to disperse the waves. For this reason, there has been proposed a wave suppressing device for a ship that suppresses the generation of waves by suppressing the crest of waves generated during navigation from above with such wave suppressing plates (see, for example, Patent Document 1).

Similarly, a plurality of wing bodies with airfoil cross-sections are arranged in parallel in the front-rear direction at predetermined intervals rearward from the stern end, and the stern wave is split forward and backward by the plurality of wing bodies. A stern tow wave reducing device has been proposed that reduces the wave height of tow waves caused by stern tug waves (see, for example, Patent Document 2).

However, in order to suppress or split these wave crests, it is necessary to suppress or split the waves generated at the stern by their wavelength-based length. For example, if the speed of the ship (ship speed) is Vs, the wavelength Lw of the transverse wave generated in the direction directly behind the ship is "Lw=2π/g×Vs×Vs", so the ship speed Vs is 12 knots ( 6.17 [m/s]), the wavelength Lw is 24.4 m. Also, since tug waves are generated as a result of wide-range currents at the stern, it is thought that limiting or breaking up the wave crest in a narrow area at the stern would have limited effect. .

On the other hand, as a method of reducing the wave-making resistance of ships, there is a method of installing a bow valve, which has greatly contributed to the reduction of wave-making resistance. This bow valve can reduce wave formation with only a few percent of the displacement of the hull. Optimized for size.

However, in a ship with a bow with a bulb (bulb bow shape), the bow valve is fixedly arranged integrally with the bow, so the size, shape and position of the bow valve vary depending on one "loading condition" (usually The bow valve is optimized to correspond to the shape of the front half of the hull in that state so that the wave dissipating effect is maximized for the conditions of "full load" and speed (planned cruising speed). there is

In a ship with a valve bow, the effect of the bow valve is large in a fully loaded state, and the wave-making resistance is reduced. In addition to this, there is a problem that the bow valve increases wave-making resistance, frictional resistance, and the like.

In order to solve the problem of increased resistance in light-load conditions, horizontal fins (HBF) are installed on the bow, or two valves, one for light-load conditions and the other for full-load conditions, are installed to create a two-stage valve structure. In addition, it has been proposed to configure the shape of the bow bulb, the longitudinal position, and the vertical position to be variable. In addition, the shape of the bow bulb, which is half-exposed to the surface of the water in the ballast state (light-loaded state), is changed from a spherical bulb to a long-protruding thin bulb with a small water line entry angle to reduce wave-making resistance. A method of making a hull form with a new shaped bow without valves has been adopted.

In this way, in many ships, the bow valve is used to reduce the wave-making resistance. In other words, it is considered that there is room for further research and technological development to reduce tow waves and wave-making resistance under various loading conditions and various ship speeds.

On the other hand, free waves such as bow waves, as schematically shown in FIG. Each elemental wave Aw(θ) is a surface wave having a wavelength Lw(θ) in each direction, and the free wave is considered to be a synthesis of these elemental waves be done.

Therefore, the water particles inside the free wave are considered to be in circular motion. have reverse velocity. Regarding the energy of the surface wave, in the case of regular waves, the kinetic energy Ek per unit width for one wavelength is "Ek = (1/16)×ρ×g×H×H”, and the potential energy Ep is “Ep=(1/16)×ρ×g×H×H”, so the total wave energy Ew is “Ek= (1/8)×ρ×g×H×H”.

In other words, the fact that bow waves, stern waves, and the like are generated and free waves are propagating means that part of the propulsive energy is propagated and dissipated to the outside as the wave energy of the free waves. In other words, the wave energy of this free wave becomes part of the wave-making resistance and is consumed without being used for propulsion of the ship.

Since the free wave of the bow system wave is generated from the bow and the shoulder, it is located in a position where it is easy to use from the ship very close to the hull. It can be seen that the flow is almost constant. In other words, while the ship is navigating, part of the wave generated by the hull spreads in a fan shape along the broadside.

When viewed in the ship-fixed coordinate system, this wave flow maintains the same wave shape, but in the crests of the wave, the speed is faster than the ship's navigation speed. flow with a relative velocity. As for the vertical direction of the ship, the wave along the broadside forms a crest that rises upward, and behind it forms a valley that descends downward, and these peaks and valleys are repeated along the broadside.

On the other hand, although not wave energy, one of the systems that converts the kinetic energy of the flow into electric power is a tidal current power generation system that uses the kinetic energy of the tidal current to generate electricity. In this tidal current power generation system, for example, a tidal current power generation device having a double-tube structure of an outer cylinder and an inner cylinder is provided with trumpet-shaped inclined surface portions at both ends of the inner cylinder, and a plurality of serially installed screws are provided in the inner cylinder. A configuration has been proposed in which a generator is provided in the upper space between the outer cylinder and the inner cylinder (see, for example, Patent Document 3).

In addition, a floating hydroelectric power generator using a water wheel with a horizontal axis (see, for example, Patent Document 4) and a tidal current power generation system equipped with a Darrieus type water turbine with a vertical axis (see, for example, Patent Document 5) have been proposed. ing. Furthermore, a hull-mounted paddle-wheel water turbine (see, for example, Patent Document 6) has also been proposed. not a thing

Furthermore, as one of the systems that utilizes the potential energy of waves to generate electricity, waves are stored in a reservoir or the like, and the difference in height between the reservoir surface and the sea surface is used to discharge water into the sea. An overtopping type wave power generation system that generates power by rotating has been proposed (see, for example, Patent Document 7).

In addition, although it is not wave energy, as an attempt to recover the kinetic energy of the flow, by generating power with the impeller provided inside the through passage formed in the bulbous bow of the ship and the bulbous bow formed as an impeller, An energy-saving ship that generates power by recovering energy from the flow in the vicinity of the bulbous bow during propulsion of the ship has been proposed (see, for example, Patent Document 8).

However, in this energy-saving ship, when energy is recovered from the flow in the vicinity of the bulbous bow, the flow around the bulbous bow changes. In addition, the kinetic energy of the external current is converted into electrical energy, and the reduction in the kinetic energy of the external current becomes resistance of the ship in the same way as the wake of the ship, so energy loss during energy conversion. It is thought that it will be at a disadvantage.

JP-A-9-175478 JP-A-11-180379 JP 2020-200824 A JP-A-2007-9830 JP-A-2000-265936 Japanese Utility Model Laid-Open No. 6-8769 JP 2015-229964 A JP 2011-240806 A

As mentioned above, many ships have been trying to reduce wave-making resistance by using bow valves, etc. In other words, there is room for further research and technological development to reduce tow waves and wave-making resistance under various loading conditions and ship speeds.

The present invention has been made in view of the above, and the object of the present invention is not to reduce the waves generated by the hull such as the bow and stern, but to reduce the energy of the generated waves. It is an object of the present invention to provide a wave energy recovery system for a ship, a ship, a tug wave reduction method for a ship, and the like, which reduce tug waves propagating from a hull by recovering a portion of the hull.

A wave energy recovery system for a vessel according to the present invention for achieving the above objects is a wave energy recovery system installed in a vessel that generates tow waves during cruising, and the system comprises: located where the tow wave is present or guided while underway to recover a portion of the wave energy of the tow wave generated by the submerged portion of the hull of the vessel; A wave energy recovery system for ships characterized by:

The "tug wave" referred to here includes not only "bow waves" generated at the bow and bow shoulders, but also "stern waves" generated at the stern shoulders and stern. It is a free wave that propagates outward from the ship generated in the whole area. Note that local waves that do not propagate to the outside are not considered here, but near the hull, these local waves are also included in the waves that flow along the hull. In some cases, the wave energy of local waves is also recovered. In addition, when a wave energy recovery device is installed on a ship, since part of the bow wave flows along the broadside, the wave energy is more likely to be recovered from the bow wave than the stern wave. .

In addition, since tug waves occur not only in displacement-type ships but also in planing-type ships and the like, it is not necessary to limit the types of ships to which the present invention is applied only to displacement-type ships. It is the subject of the present invention.

Also, "at least when the ship is sailing forward" means "when the ship is not sailing forward, it may be excluded." In other words, the wave energy recovery device may be movably provided and housed or housed inside the hull or on the upper deck when not in use, such as when the ship is docked.

This wave energy recovery device is a device that converts a part of wave energy, which consists of kinetic energy and potential energy, into other forms of energy such as rotational energy around a rotation axis. As a device for this conversion, for example, for kinetic energy, a water wheel used in tidal current power generation is a reference, and for potential energy, a water wheel used in a wave overtopping type wave power generation device, a water wheel used in hydroelectric power generation, etc. Helpful.

And usually, the rotational energy obtained by these water turbines can be used by ships by converting it into an energy form that is easy to use, such as electric power. If the electrical energy recovered from this wave energy is used as part of the propulsion energy, the wave-making drag will be substantially reduced. It should be noted that tug waves can be reduced by recovering or dissipating some of the wave energy without converting it to usable energy.

Next, features of the present invention will be described. A feature of the present invention is that by recovering a portion of the wave energy of the tug wave that is generated after the ship has generated the wave, the tug that propagates to the outside, without being involved in the wave generation of the ship. The object is to reduce waves and to provide this wave energy recovery device on a ship generating this tug wave.

In order to facilitate understanding of the advantages of providing a wave energy recovery device on a ship, first, while a wave energy recovery device separate from the ship is sailing parallel to the ship, the wave energy of the tow wave of the ship is generated. Consider the case of collecting In this case, the separate wave energy recovery device can recover part of the wave energy of the tow of the ship, and the tow is reduced after part of the wave energy has been recovered.

Consider the case where this parallel sailing separate wave energy recovery device is arranged on a ship. In this arrangement, by arranging it in a position that does not affect the generation of bow waves (for example, a position slightly behind the shoulder of the hull), it will not affect the generation of free waves (tow waves) such as bow waves. A portion of the wave energy of the free waves propagating from the hull can be recovered without input. Note that the free wave propagating from the hull has a different propagation mode and a different waveform due to the presence of the wave energy recovery device. However, if the recovered wave energy is greater than the wave energy generated by the wave energy recovery device, the wave energy of the free wave propagating outward will be reduced.

Next, let us consider the reduction of wave-making resistance by the wave energy recovery device. In order to sail a wave energy recovery device separate from a ship in parallel with the ship, energy for navigation is required for the device to sail against the propulsion resistance of the device. The size of the energy for navigation and the energy recovered depends on various factors such as the navigation speed of the device, the magnitude of the tow wave, and the recovery efficiency. However, it can be seen from the development of ships that use wave energy to propel themselves that the recovered energy of this wave may be greater than the energy for navigation.

Then, it is conceivable that the recovery energy can be made larger than the propulsion resistance of the wave energy recovery device fixed to the ship, and can be used as part of the energy used in the ship. In this case, it is considered that there is not only the effect of reducing tow waves but also the substantial effect of reducing wave-making resistance. Furthermore, by recovering the kinetic energy from the waves flowing along the side of the ship, it is possible to reduce the flow velocity of the water flowing along the side of the ship. .

The configuration for recovering the wave energy of tow waves with this ship wave energy recovery device has the following advantages. The first advantage is that wave energy is recovered from free waves (tug waves, target waves) generated in the submerged portion of the hull, so that it can be installed in existing ships as well. The second advantage is that it is a device for waves that have already been generated, so regardless of the shape of the bow of the hull, in other words, the effect of reducing tow waves is not affected by the presence or absence of bow valves. It is a point that can demonstrate

The third advantage is that if a water turbine or the like can be placed in a place where towed waves exist, a certain amount of wave energy can be recovered, so the number of model tests and numerical simulation tests can be reduced, making design easier. at the point of becoming The fourth advantage is that it is relatively easy to adjust the arrangement position (longitudinal position, width direction position, vertical position, inclination angle), capacity, etc. of the wave energy recovery device in response to changes in the state of the submerged portion of the hull and the speed of the ship. to optimize the wave energy recovery efficiency.

Further, in the wave energy recovery system for ships, the wave energy recovery device may include a water wheel converting part of the kinetic energy of the tow waves into rotational kinetic energy, or a part of the potential energy of the tow waves. It comprises a water wheel that converts into rotational kinetic energy or a water wheel that converts both part of the kinetic energy and part of the potential energy of said tug wave into rotational kinetic energy.

Regarding the kinetic energy of a tug wave, when viewed from a hull-fixed coordinate system that moves with the ship, the velocity of water particles increases at the peaks of the tug wave, and the velocity of water particles increases at the troughs of the wave. As it slows down and flows outside the broadside of the hull, it recovers some of the wave's kinetic energy from this flow. In addition, regarding the potential energy of tow waves, the crests of the waves are higher than the average water surface, and the troughs are lower than the average water surface. can recover some of the wave's potential energy.

In the above-described wave energy recovery system for ships, the wave energy recovery device is an axial flow type water turbine in which the rotating shaft is arranged in the direction of wave flow or in the longitudinal direction of the ship, and the rotating shaft is arranged in the horizontal direction. When equipped with either a horizontal axis type water turbine with a vertical axis of rotation or a vertical axis type water turbine with a vertical axis of rotation, using the technology of each turbine in the prior art, part of the wave energy of the tug wave can be recovered.

Further, in the wave energy recovery system for ships, if the wave energy recovery device includes a duct that covers the water turbine or a water conduit that introduces water to the water turbine, wave energy recovery efficiency is improved. can be made Here, "duct" refers to a member that encloses a water wheel and has a relatively short length and a relatively simple shape. , the waterwheel need not necessarily be enclosed, and the rear end of the "headrace" may end at a position in front of the waterwheel or may extend to a position behind the waterwheel.

Further, in the above ship, if a movement mechanism is provided for changing at least one of the position of part or all of the wave energy recovery device with respect to the ship, the angle of vertical inclination, or the angle of horizontal inclination, the following can be achieved. can be effective. In other words, since the wavelength of the tow wave (free wave) generated by the ship changes in proportion to the square of the ship speed, when viewed from the hull-fixed coordinates, the ridges and valleys of the tow wave ( However, by moving the position of the wave energy recovery device or changing the inclination angle in response to the change in the position of the peaks and troughs of the waves, it is possible to follow the changes in the ship speed. Become. In addition, the volume and draft position of the submerged portion of the hull change according to the loading condition of the ship, and the vertical position of the tow wave generated in the submerged portion of the hull also changes. It can be handled by moving the device up and down.

In the above wave energy recovery system for ships, if part or all of the wave energy recovery device is provided with a housing mechanism for housing inside the hull of the ship, on the upper deck, or above the upper deck, It is possible to prevent the wave energy recovery device from becoming an obstacle during berthing work, towing work by a tugboat, or the like.

In the wave energy recovery system for ships, when the wave energy recovery device is configured to be towed by the ship, the movement operation and storage work of the wave energy recovery device can be significantly simplified, and It is possible to simplify the mounting structure and the like on the ship side for equipping the ship with the wave energy recovery system, and to simplify the mounting work.

A ship for achieving the above object is characterized by comprising any one of the wave energy recovery systems for ships described above. With this configuration, it is possible to achieve the same effects as the wave energy recovery systems for ships described above.

In the above-mentioned ship, when the ship is sailing at least in the forward direction, the wave energy recovery device is placed on the side of the submerged portion of the hull, away from the surface of the submerged portion of the hull, or When configured to be placed in contact with the surface of the submerged portion of the hull, the wave energy recovery device can be easily placed where there is a bow wave tug.

When the ship is a monohull, it is preferable to arrange them in pairs on both sides of the submerged part of the hull. Instead, they can be placed in the channel between the hulls to increase the amount of wave energy that can be recovered. In multi-hulls, similarly, the amount of wave energy that can be recovered can be increased by placing them in the channel between each hull, rather than just on the outer side of the outermost hull.

Further, in the above-mentioned ship, if a guiding member composed of guiding fins or guiding plates for guiding a part or all of the towed waves to the wave energy recovery device is provided, the guiding member converts the towed waves into wave energy. Directing to a recovery device can increase the amount of wave energy that can be recovered.

The term "guiding fin" used herein refers to a wing-shaped or plate-shaped member relatively short in the longitudinal direction of the ship for controlling the flow in the vertical direction of the ship. Further, a "guiding plate" refers to a relatively long plate-like member in the longitudinal direction of the ship for controlling the flow in the vertical direction of the ship.

In the above ship, the rear half of the submerged portion of the hull is below the full load line or the planned waterline in the vertical direction of the ship, continuously or intermittently in a range of at least 50% in the depth direction. When 70% of the water plane shape is formed by the shape of the rear half of the symmetrical wing, in other words, 70% of the water plane shape of the rear half of the submerged portion of the hull is 70% of the shape of the rear half of the symmetrical wing. %, the following effects can be exhibited.

According to this configuration, most of the rear half of the submerged portion of the hull is formed in the shape of the rear half of the symmetrical wing, so the flow on the stern side can be simplified, and the generation of waves by the rear shoulder and stern can be suppressed. Therefore, it is possible to greatly reduce the tug wave generated in the rear half of the submerged portion of the hull as a whole tug wave.

A method for reducing tug waves for a ship to achieve the above object is a method for reducing tug waves of a ship, at least when the ship is sailing in a forward direction, on both sides of the ship or behind the ship. reducing the wave energy of the tow waves generated by the ship by recovering a portion of the wave energy of the tow waves generated by the submerged portion of the hull of the ship, with wave energy recovery devices arranged A tow wave reduction method for a ship characterized by:

Alternatively, a ship tug wave reduction method for achieving the above object is characterized by reducing the wave energy of the ship tug wave using any of the wave energy recovery systems for ships described above. A tow wave reduction method for ships.

According to these ship tug wave reduction methods, by recovering the wave energy of the tug wave generated in the submerged portion of the hull of the ship, it is possible to reduce the wave energy of the tug wave propagating outward from the ship. can.

A method of modifying a ship for achieving the above object is a method of modifying a ship, characterized in that any one of the ship wave energy recovery systems described above is added to an existing ship. According to this method, the same effects as those of the methods for reducing tow waves for ships described above can be exhibited.

According to the wave energy recovery system for a ship, the ship, the tow wave reduction method for a ship, etc. of the present invention, regardless of the shape of the hull including the shape of the bow, the tow wave generated by the submerged portion of the hull can be On the other hand, by recovering part of the wave energy of the tow waves, the effect of reducing the wave energy of the tow waves can be obtained.

FIG. 1 is a system configuration diagram illustrating the configuration of a wave energy recovery system according to an embodiment of the present invention. FIG. 2 is a diagram schematically illustrating a first example (axial flow turbine) of the wave energy recovery system according to the first embodiment of the present invention and a bow side portion of a ship equipped with this wave energy recovery system. (a) is a side view seen from the starboard side, (b) is a bottom view seen from the ship bottom side, and (c) is a front view seen from the front. Fig. 3 is a schematic view of the vicinity of the bow, enlarging a part of Fig. 2, (a) is a side view seen from the starboard side, (b) is a bottom view seen from the bottom side, and (c) It is a front view of the port side seen from the front. FIG. 4 is a schematic view of the vicinity of the bow of a vessel equipped with the second example (axial flow turbine with duct) of the wave energy recovery system according to the first embodiment of the present invention, and (a) is viewed from the starboard side. It is a side view seen, (b) is a bottom view seen from the ship's bottom side, and (c) is a front view seen from the port side seen from the front. FIG. 5 is a schematic diagram of the vicinity of the bow of a ship equipped with a third example (horizontal axis type water turbine) of the wave energy recovery system according to the first embodiment of the present invention, and (a) is a view from the starboard side. It is a side view, (b) is a bottom view seen from the bottom side of the ship, and (c) is a front view of the port side seen from the front. FIG. 6 is a schematic diagram of the vicinity of the bow of a vessel equipped with the fourth example (vertical axis type water turbine) of the wave energy recovery system according to the first embodiment of the present invention, and (a) is seen from the starboard side. It is a side view, (b) is a bottom view seen from the bottom side of the ship, and (c) is a front view of the port side seen from the front. FIG. 7 is a schematic diagram of the vicinity of the bow of a ship equipped with the first example (simplified water conduit) of the wave energy recovery system according to the second embodiment of the present invention, and (a) is viewed from the starboard side. It is a side view, (b) is a bottom view seen from the bottom side of the ship, and (c) is a front view of the port side seen from the front. FIG. 8 is a schematic view of the vicinity of the bow of a ship equipped with a second example of the wave energy recovery system according to the second embodiment of the present invention (a water turbine is arranged in a vertical channel), and (a) is from the starboard side. It is a side view seen, (b) is a bottom view seen from the ship's bottom side, and (c) is a front view seen from the port side seen from the front. FIG. 9 is a schematic diagram of the vicinity of the bow of a vessel equipped with a third example of the wave energy recovery system according to the second embodiment of the present invention (a water turbine is arranged in a horizontal drainage channel), and (a) is the starboard side. (b) is a bottom view seen from the bottom side of the ship, and (c) is a front view of the port side seen from the front. FIG. 10 is a schematic view of the vicinity of the bow of a vessel equipped with a fourth example of the wave energy recovery system according to the second embodiment of the present invention (a water turbine is arranged in an inclined channel), and (a) is from the starboard side. It is a side view seen, (b) is a bottom view seen from the ship's bottom side, and (c) is a front view seen from the port side seen from the front. FIG. 11 is a schematic diagram of the vicinity of the bow of a vessel equipped with a fifth example of the wave energy recovery system according to the second embodiment of the present invention (with a water turbine arranged in a siphon-type channel). (b) is a bottom view seen from the bottom side of the ship, and (c) is a front view of the port side seen from the front. FIG. 12 is a schematic diagram of the vicinity of the bow of a vessel equipped with the first example of the wave energy recovery system according to the third embodiment of the present invention (the water turbine outside the headrace and the water turbine inside the headrace); It is a side view seen from the starboard side, (b) is a bottom view seen from the ship bottom side, and (c) is a front view seen from the port side seen from the front. FIG. 13 is a schematic diagram of the vicinity of the bow of a vessel equipped with a second example of the wave energy recovery system (two water turbines in the water conduit) according to the third embodiment of the present invention, (a) being the starboard side. (b) is a bottom view seen from the bottom side of the ship, and (c) is a front view of the port side seen from the front. FIG. 14 is a schematic diagram of the vicinity of the bow of a vessel equipped with a third example of the wave energy recovery system according to the third embodiment of the present invention (one water turbine in an inclined channel), (a) being the starboard side. (b) is a bottom view seen from the bottom side of the ship, and (c) is a front view of the port side seen from the front. FIG. 15 is a cross-sectional view for explaining the accommodation mechanism of the rotating type wave energy recovery device. FIG. 16 is a cross-sectional view for explaining the accommodation mechanism of the overturning type wave energy recovery device, and is a view showing movement between the concave portion on the side of the ship. FIG. 17 is a cross-sectional view for explaining another example of the accommodation mechanism of the overturning type wave energy recovery device, and is a view showing movement between upper decks. FIG. 18 is a cross-sectional view for explaining the housing mechanism of the telescopic type wave energy recovery device. FIG. 19 is a cross-sectional view for explaining the housing mechanism of the lifting type wave energy recovery device. FIG. 20 is a schematic diagram showing the configuration of a towed wave energy recovery device, where (a) is a side view, (b) is a plan view, (c) is a bottom view, and (d) is a front view. is. Fig. 21 is a schematic diagram of the vicinity of the bow of a ship equipped with the tow-type wave energy recovery device of Fig. 20, (a) is a side view seen from the starboard side, and (b) is a bottom view seen from the bottom side of the ship. In the figure, (c) is a front view of the port side seen from the front. FIG. 22 is a diagram showing the ship of the first embodiment, and is a plan view schematically showing the ship in which the wave energy recovery system is arranged. 23A and 23B are diagrams showing a ship according to the second embodiment, and FIG. 23A schematically shows a ship in which the rear half of the submerged portion of the hull is formed in an airfoil shape and a wave energy recovery system is arranged. and (b) is a diagram showing the airfoil shape of the "NACA0020 airfoil". FIG. 24 is a plan view schematically showing an example of comparison between the arrangement position of the wave energy recovery device and the wave pattern with respect to bow wave system waves of a ship. FIG. 25 is a plan view schematically showing an example of comparison between the arrangement position of the wave energy recovery device and the wave pattern with respect to the stern wave of the ship. FIG. 26 is a schematic diagram of the vicinity of the bow of a ship equipped with guide fins, (a) is a side view seen from the starboard side, (b) is a bottom view seen from the bottom side, and (c) is a front view. 1 is a front view of the port side as seen from the . FIG. 27 is a schematic diagram of the vicinity of the bow of a ship equipped with a guide plate (in the width direction), (a) is a side view seen from the starboard side, (b) is a bottom view seen from the bottom side, ( c) is a front view of the port side seen from the front. Fig. 28 is a schematic diagram of the vicinity of the bow of a ship equipped with guide fins and guide plates (in the width direction), (a) is a side view seen from the starboard side, and (b) is a bottom view seen from the bottom side of the ship. and (c) is a front view of the port side as seen from the front. FIG. 29 is a schematic diagram of the vicinity of the bow of a ship equipped with guide fins (with end plates) and guide plates (in the vertical direction), (a) is a side view seen from the starboard side, and (b) is a bottom side view. (c) is a front view of the port side as seen from the front. FIG. 30 is a plan view for explaining the wave pattern of Kelvin waves. FIG. 31 is a plan view schematically illustrating the size of a Kelvin wave pattern at a sailing speed of 12 knots and the size of a VLCC, a high-speed container ship, and an escort ship. FIG. 32 is a plan view schematically illustrating the magnitude of the wave pattern of Kelvin waves at a cruising speed of 15.5 knots in the VLCC and the magnitude of the VLCC. FIG. 33 is a plan view schematically illustrating the size of a Kelvin wave pattern of a high-speed container ship at a sailing speed of 23.5 knots and the size of the high-speed container ship. FIG. 34 is a plan view schematically illustrating the size of the wave pattern of Kelvin waves at a cruise speed of 30 knots on an escort ship and the size of the escort ship.

[Intro and General Description of the Figures] Hereinafter, embodiments of a wave energy recovery system for a ship, a ship, a method for reducing tow waves for a ship, and a method for modifying a ship according to the present invention will be described with reference to the drawings.

First, the drawings will be described. FIG. 1 is a system configuration diagram illustrating the configuration of a wave energy recovery system, and FIGS. More particularly, FIGS. 2-6 are diagrams of a first embodiment wave energy recovery device 20A for recovering kinetic energy, and FIGS. 7-11 are for a second embodiment of recovering potential energy. FIG. 12 to FIG. 14 are diagrams for a wave energy recovery device 20B in the form of , and FIGS. 12 to 14 are diagrams for a wave energy recovery device 20C in a third embodiment that recovers both kinetic energy and potential energy.

15 to 21 are diagrams relating to the housing mechanism of the wave energy recovery device. 22 to 25 are diagrams relating to ships equipped with the wave energy recovery systems of the first and second embodiments. 26 to 29 are diagrams relating to the guide member 5 installed on the ship 1. FIG. 30 to 34 are diagrams relating to the wave pattern and the sailing speed of the ship.

It should be noted that the drawings shown here are schematic diagrams for explaining the present invention, and are not necessarily shown in exact dimensional proportions, nor do they necessarily show exact positions. The symbol "Lc" is the hull center line indicating the hull center cross section, and the same symbol "Lc" is used in the plan view, the bottom view, the front view, the rear view, and the like.

[Definition of terms] Prior to the following description, the coordinate system and terms used here ("submerged portion of hull", "tow", and "source of tug") will be defined or explained.

First, as a coordinate system, a right-handed XYZ coordinate system (a moving coordinate system that moves with the ship) is adopted as an orthogonal coordinate system fixed to the ship, and the X direction is defined as the "forward and backward direction of the ship (hereinafter abbreviated The Y direction is defined as the "width direction of the ship (hereinafter abbreviated as the 'width direction')", and the Z direction is defined as the 'vertical direction of the ship (hereinafter abbreviated as the 'vertical direction'). say)”. Since the coordinate system is used here as an aid to clarify the direction, it is not necessary to fix the origin of the coordinate system. is the center of gravity of Also, when the ship is traveling straight ahead, the forward direction of the ship coincides with the X direction in the longitudinal direction of the ship.

"Hull submerged part (2)" is when the target ship is sailing under "target condition (Ct) = target loading condition (St) and target sailing speed (Vst)" Defined as the part of the hull that is submerged. Also, here, a free wave generated when the submerged portion of the hull is sailing is defined as a tug wave (Aw).

In addition, tug waves are generated in the submerged part of the hull, but even if this submerged part of the hull can be represented macroscopically as a point source, locally it is a concrete object that occupies a three-dimensional space. . On the other hand, the "source of tug wave (Awp)" is defined as the intersection point of the envelope of the wave pattern generated by the submerged portion of the hull, in other words, the vertex corresponding to the corner of the wave pattern sector. , is a virtual wave source.

Generally, the position of the tip of the submerged part of the hull and the position of the tug wave generation source do not match. However, the position of the tug wave generation source can be obtained from the wave pattern of the target wave obtained in a water tank test of a model ship. Normally, the position of the tow wave generation source is ahead of the position of the tip of the submerged portion of the hull.

[Object of the present invention] As for the ships to which the present invention is applied, the primary object of the present invention is to reduce the wave energy of the tow waves generated from the ships. Not only displacement type vessels such as relatively low speed vessels, but also relatively high speed vessels such as container ships, large ferries and naval vessels, and other hydrofoil and planing vessels. Moreover, it can be applied not only to monohulls but also to multihulls such as catamarans and trimarans.

In addition, the present invention can obtain a substantial effect of reducing wave-making resistance by adding a wave energy recovery function for ships to a ship, using part of the wave energy of tow waves as propulsion energy. is the second purpose. This wave energy recovery system for ships is a system for tug waves that have already been generated by ship building, so it can be used regardless of new ships or existing ships.

[Tail wave targeted by the present invention] Next, the tow wave targeted by the present invention will be described. A ship is generally elongated fore and aft, and is formed by a bow, a center parallel portion of the hull, and a stern. Waves generated in the submerged part of the hull are those in which the cross-sectional area of the hull changes rapidly, especially the bow, the shoulder where the bow transitions from the bow to the mid-parallel part of the hull, and the bow from the mid-parallel part to the stern. Waves generated in the four parts of the stern shoulder and stern have a large influence, and a complex wave system is generated by synthesizing these waves. It should be noted that the waves generated at the forward and aft shoulders are said to be relatively smaller than the waves generated at the bow and stern.

A portion of these wave systems becomes tug waves (free waves) and propagates to the outside, causing energy loss as the ship sails, and becomes a major part of the resistance component called wave-making resistance. Of these waves, the tug wave targeted by the present invention is usually the tug wave of the bow system generated in the front half of the submerged part of the hull. Depending on the situation, tug waves generated in the entire submerged hull including stern waves generated in the latter half of the submerged hull can be targeted. At the bow, in addition to wave-making resistance due to free waves, there are resistance components such as resistance due to local waves such as breaking waves and spray resistance. may also decrease.

A more detailed description will now be given with reference to FIG. In practice, the wave pattern of the tug wave source Awp of the tug wave generated by the ship is actually deviates from the wave pattern of Kelvin waves, but for simplicity of explanation, we will proceed without considering these effects. That is, here, for ease of explanation, the wave pattern of a simple Kelvin wave will be explained. Although the actual wave pattern deviates from the theoretical Kelvin wave pattern, the calculated value of the nonlinear Kelvin wave including the influence of the local wave agrees well with the measured "figure eight wave". There are also reports.

Although the wave pattern illustrated in FIG. 30 is meant to imitate a simple Kelvin wave pattern, it is not necessarily an accurate theoretical Kelvin wave pattern. Further, when the tug wave generation source Awp is traveling at the traveling speed Va, when viewed from the coordinate system fixed to the tug wave generation source Awp, the wave moves behind the tug wave generation source Awp due to the velocity Vw of the inflowing water. It will flow away.

As shown in FIG. 30, the tug wave (free wave) Aw propagating to the outside of the tug wave generation source Awp has the following relationship between the traveling velocity Va of the tug wave generation source Awp and the propagation velocity of the tug wave Aw. It propagates inside the sector of the Kelvin wave pattern. A wave propagating in a direction deviating from the traveling direction of the tug wave generation source Awp by an angle of θ is called an elementary wave Aw(θ). The wavelength Lw(.theta.) of this elementary wave Aw(.theta.) has a constant and regularly arranged phase front.

Regarding the wavelength Lw(θ) of the elementary wave Aw(θ), if the water area is not shallow or narrow, the wavelength Lw(θ) is "Lw (θ)=2π/g×Va ² ×cos ² θ=0.64×Va ² ×cos ² θ" ( m). Here, “g” is the acceleration of gravity (9.8 m/s ² ).

The elemental wave Aw(θ) of this tug wave is divided into a longitudinal wave Awc and a transverse wave Awd when distinguished by the propagation direction θ. Longitudinal wave Awc is called "diffusion wave", "divergent wave", etc., and from tug wave generation source (wake source, etc.) Awp, diagonally forward or lateral direction (θ ≧ about 35 degrees: theoretically 35 degrees 16 However, since the tug wave generation source Awp moves forward, the wave spreads obliquely backward when viewed in a coordinate system fixed to the tug wave generation source Awp. On the other hand, the transverse wave Awd is a wave that propagates in the backward direction (θ≦approximately 35 degrees: theoretically 35 degrees 16 minutes) of the tug wave generation source Awp, and the center is on the path (Lac) of the tug wave generation source Awp. The distance from this transverse wave Awd to the tug wave generation source Awp is equal to the radius of the arc.

The vertex where the crest of the longitudinal wave Awc and the crest of the transverse wave Awd intersect is called a cusp, and the line (cusp line) Lap connecting the outermost cusp Pac (i: i=1, 2, 3 . . . ) is linear. Theoretically, θc (approximately 20 degrees: theoretically 19 degrees 28 minutes) on each side from the bow direction with the tow wave generation source Awp at the top, regardless of the traveling speed Va of the tow wave generation source Awp. A straight line Lap opened at . This cuspline Lap is the foremost ridgeline of the towed wave Aw generated by the towed wave generation source Awp, and the towed wave Aw is propagated within a fan-shaped range behind the two cusplines Lap. I never go outside.

A wave pattern formed by synthesizing peaks and valleys of the elemental wave Aw(θ) of the tug wave forms a constant wave pattern. The positions of peaks and troughs of the tug wave Aw, which is a set of the elementary waves Aw(θ), change with the square of the traveling speed Va. On the other hand, the magnitude of the amplitude of peaks and valleys of the tow wave Aw depends on the characteristics of the tow wave generation source Awp (for example, the shape of the submerged portion of the hull). Varies depending on Therefore, even if the traveling speed Va is the same, each wave pattern is formed according to the characteristic of the tug wave generation source Awp. That is, the wave pattern differs according to the characteristics of the towing wave source Awp, in other words, the shape of the submerged portion of the ship's hull.

[Water Depth Affected by Waves] Next, the depth of water affected by the tow waves Aw will be examined. Considered in a stationary coordinate system, the motion of water particles in waves decays exponentially with water depth, and at depths greater than half the wavelength, the motion of water particles is about 4% of the water surface. Also, since the wave energy is proportional to the square of the velocity of water particles, it is about 8% at a depth of 0.2 times the wavelength and about 1% at a depth of 0.37 times the wavelength. Therefore, tentatively, here, as a target range for recovering the kinetic energy of the wave energy to be absorbed, a range from the water surface to a water depth 0.2 times the wavelength is considered, and this water depth is defined as the target water depth De. .

Here, let's consider practical application as a countermeasure against tow waves when navigating such as the Uraga Suido route in Tokyo Bay. Since these routes are supposed to navigate at 12 knots (approximately 6.17 [m/s]) or less, wavelength Lw0 = Lw (0°) = 24.4 m or less, target water depth De = 4.88 m It is as follows.

For reference, consider an oversized tanker called Malaccamax, a high-speed container ship called 23,000 TEU class, and an escort ship called DDG179.

The specifications of this enlarged tanker ship are 300,000 tons deadweight, 333m length (Lt), 60m width (Bt), 20.5m full draft (dc), and 15.5m sailing speed (Vs). 5 knots (approximately 8.0 [m/s]) and the main engine output is 27,020 kW. In this large tanker ship, the sailing speed Vst is 15.5 knots (approximately 8.0 [m/s]), the wavelength Lw0 is 40.1 m, and the target water depth De is 8.02 m.

The specifications of this high-speed container ship are 225,000 tons deadweight, length (Lc) of 400m, width (Bc) of 61.5m, full draft (dc) of 16.4m, and sailing speed ( Vs) is 23.5 knots (approximately 12.1 [m/s]), and the main engine output is 60,000 kW. In this high-speed container ship, the cruising speed Vst is 23.5 knots (about 12.1 [m/s]), the wavelength Lw0 is 93.7 m, and the target water depth De is 18.72 m.

The specifications of this escort ship are 8200 tons of standard displacement tons, 170m of length (Ld), 21m of width (Bd), 6.2m of draft (dd), and 30 knots of sailing speed (Vs). about 15.4 [m/s]). In this destroyer, the navigation speed Vst is approximately 30 knots (approximately 15.4 [m/s]), Lw0 is 151.8 m, and the target water depth De is 30.36 m.

Therefore, the full load draft (dc) is 20.5m for the hypertanker ship, 16.4m for the high speed container ship, and 6.2m for the escort ship (dd). For commercial vessels such as hypertankers and high-speed container ships, we believe that much of the kinetic energy of tug waves can be recovered from the bottom to the depth of the draft.

31 to 34 schematically show a comparison between the size of the wave pattern of the tug wave and the size of the actual ship. FIG. 31 is a plan view schematically showing the relationship between a 12-knot wave pattern and the size of an actual ship on a route where the sailing speed is restricted. Also, FIG. 32 shows the case of a captain and a bloated tanker ship with a sailing speed Vst of 15.5 knots, FIG. Captain, let me show you the case of an escort ship with a cruising speed Vst of 30 knots.

Looking at the relationship between the ship length and the wave pattern in Figures 31 to 34, for a cruising speed of 12 knots, many ships have tug wave crests along the broadside for bow waves. Accordingly, it is conceivable that a wave energy recovery system 10 for ships as described below can be placed on the ship 1 . In addition, regarding normal navigation speed, it can be installed on commercial ships such as hypertankers and high-speed container ships, but it is difficult to install it on ships that navigate at relatively high speeds such as escort ships.

Appropriate placement positions of the ship wave energy recovery system 10 on an actual ship can be set by water tank tests using model ships, numerical simulation calculations (for example, CFD), and the like. However, the wave pattern of the tug wave Aw changes due to the effects of the water depth of the route, the exclusion effect of the submerged part of the hull, the viscosity effect, the presence of local waves, etc. is movable in the longitudinal direction or the width direction within a certain range so that the position of the wave energy recovery device can be adjusted according to the sea area to be navigated.

[Wave Energy Recovery System for Ships] First, referring to FIGS. ) 10 will be described. This wave energy recovery system 10 is a system installed in a ship 1 that generates a tow wave (free wave) Aw during cruising. or a place where the tow waves Aw are guided, and recovers part of the wave energy of the tow waves Aw generated by the submerged portion 2 of the hull 1 of the ship 1.

As shown in FIG. 1, the wave energy recovery system 10 includes a wave energy recovery device 20, a support device 30 that supports the wave energy recovery device 20, and a control device 40 that controls the entire system. This wave energy recovery system 10 is usually arranged on the bow side of the ship 1, as shown in FIG. . However, it may be arranged at the stern of the ship 1, targeting the wave energy of the stern wave in the tug wave Aw, although the arrangement needs to be devised.

The wave energy recovery device 20 includes, as shown in FIG. at least one of a potential energy conversion device (water wheel, etc.) 21 for converting a portion into rotational kinetic energy, and a power generation device (generator, etc.) 23, and further, if necessary Accordingly, a water flow control mechanism (such as a water conduit) 22 that introduces the tug wave Aw into a conversion device (such as a water wheel) 21, and a mechanical motion such as the rotational motion of the energy conversion device (such as a water wheel) 21 is transferred to a power generation device (power generation A power transmission mechanism (rotating shaft and gear set, etc.) 24, etc. for transmitting power to a motor, etc.) 23 is provided.

[First Embodiment] As shown in FIGS. 2 to 6, the wave energy recovery device 20A of the first embodiment converts part of the kinetic energy of the towing wave Aw into rotational kinetic energy. It is configured with a water wheel (energy conversion device) 21 . As the water turbines 21, there are axial water turbines 21A and 21B having a rotating shaft arranged in the direction of the flow of the tug wave Aw or the longitudinal direction X of the ship, and a horizontal shaft type water turbine 21C having a rotating shaft arranged in the horizontal direction. , a vertical axis water turbine 21D having a rotation axis arranged in the vertical direction, or the like can be used.

This axial flow turbine 21A is also called a propeller turbine, and as shown in FIGS. A hydraulic turbine or the like of the power generation unit used in the device can be used. I also learned from water turbines in the field of hydroelectric power generation. For example, a propeller turbine called a reaction turbine, which is suitable for low head, and a Kaplan propeller turbine whose blade angle can be adjusted to respond to changes in flow rate, etc. The water wheel structure is also helpful.

In the case of this axial-flow type water turbine 21A, since both the inflow and the outflow of the water flow are in the direction of the rotation axis of the water turbine, it is easy to arrange equipment such as a power generator so as to be continuous with the rotation axis, so that it is easy to unitize. In addition, since the conversion efficiency is improved when the direction of the rotation axis is the same as the direction of the water flow, the movement mechanism 32 of the support device 30 is used to follow the change in the direction of the flow of the water W of the tug wave Aw. It is preferable to change not only the position of the wave energy recovery device 20A but also the angle of vertical inclination (pitch angle) α and the angle of horizontal inclination (yaw angle) β shown in FIG. Furthermore, it is preferable to adopt a variable pitch propeller or the like that can change the angle of the propeller blades so as to cope with changes in the amount of inflow.

Further, as shown in FIG. 4 as a second example, the ducted axial flow turbine 21B is configured to include a duct 21Bb around the propeller 21Ba. Propellers with ducts, side thrusters, etc. of ships are used as references for this ducted axial flow turbine 21B. ), etc., can be used as a reference.

In addition, as shown in FIG. 5 as a third example, the horizontal axis type water turbine 21C is a water turbine having the axial direction of the rotation axis in the horizontal direction (width direction Y, etc.) perpendicular to or intersecting the direction of flow of the water W. . For this horizontal shaft type water turbine 21C, for example, a paddle wheel type water turbine proposed for tidal current power generation, a cross flow type water turbine used for small hydro power generation, and the like are also useful. In order to improve the recovery efficiency of this horizontal shaft type water turbine 21C, it is necessary to set the direction of the rotating surface of the water turbine in the direction of the flow of the water W. It is preferable to configure the horizontal inclination angle (yaw angle) β to follow the change in the direction of the W flow.

Also, the vertical axis type water turbine 21D is a water turbine having the axial direction of the rotating shaft in the vertical direction, as shown in FIG. 6 as a fourth example. For the vertical axis water turbine 21D, for example, a Darrieus type water turbine that utilizes the lift force of rotor blades and a Savonius type water turbine that utilizes drag, which have been proposed for tidal current power generation, can be used as references. In order to increase the recovery efficiency of the vertical axis water turbine 21D, the direction of the rotation surface of the water turbine must be the direction of the flow of the water W. It is preferable that the horizontal inclination angle (yaw angle) β is made to follow the change in the direction of the flow of the water W.

The arrangement of the water turbines 21 when part of the kinetic energy of the towing waves Aw is converted into rotational kinetic energy is considered as follows. First, consider the arrangement of one peak of the tug wave Aw. With respect to the traveling direction of the waves, the water turbine 21 is preferably arranged in the central portion of the wave crest because the flow velocity is considered to be the fastest in the central portion of the wave crest. When the wavelength is long, a plurality of water turbines 21 may be arranged in the traveling direction with respect to one wave crest.

In addition, considering that the width of the wave is small in front of the center of the mountain and the wave energy is concentrated in a narrow range, it is better to arrange the water turbine 21 in front of the mountain, even with a compact water turbine 21. It is also considered efficient. In addition, behind the center of the mountain, the wave spreads more in the width direction, and it is thought that the wave energy is diffused over a wide range. may be available. Therefore, there may be a case where the recovery efficiency is better if the water wheel 21 is arranged behind the mountain.

Next, regarding the width direction Y of one mountain of the tow wave Aw, since the range of existence of the tow wave Aw expands as it goes backward, depending on the type of the water turbine 21, a plurality of water turbines 21 may be arranged in the width direction Y. good too. In addition, regarding the vertical direction (water depth direction) Z of one mountain of the tow waves Aw, a plurality of water turbines 21 may be arranged in the vertical direction Z from the top of the mountain of the tow waves Aw to the target water depth De. In other words, it is preferable to arrange a plurality of water turbines 21 in the range according to the wave energy distribution.

Next, let us consider the arrangement of multiple crests of tow waves. A plurality of water turbines 21 may be arranged not only for the first peak of the tug wave Aw but also for a plurality of peaks such as a second peak. In these multiple-unit arrangements, the unitized devices are connected to each other or spaced apart, and arranged at positions with good energy recovery efficiency. In any case, it is preferable to arrange the water turbine 21 in consideration of the characteristics depending on the type of the water turbine 21 and the flow velocity distribution at the position of the wave (which varies depending on the shape of the submerged portion 2 of the hull and the boat speed Vs).

Then, in order to reduce the tug wave Aw, the device itself can be simplified and made into a low-cost device. wave energy may be dissipated. Alternatively, instead of the water wheel 21, a member for dissipating wave energy may be arranged.

On the other hand, when the purpose is to recover the wave energy of the tug wave Aw, the water turbine 21 and the generator 23 are controlled in consideration of the overall energy balance of the ship 1 taking into consideration the increase/decrease in the recovered energy and the increase/decrease in the propulsion energy. preferably. In other words, since the use of the water turbine 21 increases the propulsion resistance, while considering the balance between the energy obtained and the propulsion energy required due to the increase in the propulsion resistance, the water turbine 21 and the water turbine 21, including whether or not to use the water turbine 21, should be considered. It controls the generator 23 .

[Second Embodiment] As shown in FIGS. 7 and 10, the wave energy recovery device 20B of the second embodiment converts a part of the potential energy of the towing wave Aw into rotational kinetic energy. It comprises a water wheel (energy conversion device) 21 and a water conduit (water flow control mechanism) 22 . In the wave energy recovery device 20B of the second embodiment, the water wheel 21 is rotated by utilizing the fall of the water W on the mountain of the tug wave Aw.

More specifically, it comprises a water wheel 21 and a water conduit 22 in which the water wheel 21 is arranged. The water conduit 22 comprises an inlet opening 22a, a front water conduit 22b, a water storage section 22c, a vertical water conduit 22d, a horizontal drainage conduit 22e, a drainage opening 22f, etc., in order from the inlet side as required. An air vent 22g is provided in either the front conduit 22b or the water reservoir 22c. Also, an inclined waterway 22h may be provided instead of the vertical waterway 22d and the horizontal drainage channel 22e.

The inlet opening 22a is a portion for introducing the water W of the tow waves Aw, and is opened relatively large so as to efficiently draw in the tow waves Aw and not to suck in floating matter such as dust. , it is preferable to provide a protective grid. Further, the front water conduit 22b is a water conduit that guides the water W flowing in from the inlet opening 22a to the water reservoir 22c while separating the water from the water.

The water storage part 22c temporarily stores the water W of the tug wave Aw at a position higher than the static water surface (draft line during sailing) WL, and separates air from water to discharge the air A from the air outlet 22g. is. Since the amount of inflow from the tug wave Aw is substantially constant during constant-speed sailing, the water storage part 22c may be formed of a small-capacity tank, or the water storage function may be omitted and the water storage part 22c may be used as part of the waterway. good.

The vertical water channel 22d and the horizontal drainage channel 22e are portions that drop the water W temporarily stored in the water storage portion 22c and lead it to the drainage opening 22f. Note that an inclined water channel 22h may be provided instead of the vertical water channel 22d and the horizontal drainage channel 22e. This drainage opening 22f may be submerged in water, but as shown in FIGS. Since the submerged portions of the vertical water channel 22d and the horizontal drainage channel 22e are reduced, the propulsion resistance due to water is reduced, and the water pressure at the drainage opening 22f is also eliminated, so that the water discharge resistance is reduced. However, since new waves are generated by the water W falling onto the still water surface WL, it is necessary to pay attention to the position and structure of the drainage opening 22f.

On the other hand, as shown in FIGS. 7 to 10, the water wheel 21 may be provided in any of the first half of the water channel 22 without the water reservoir 22c, the vertical water channel 22d, the horizontal drainage channel 22e, the inclined water channel 22h, or the like. A plurality of units are provided in some combinations of For this water turbine 21, like the water turbine 21 in the wave energy recovery device 20A of the first embodiment, axial flow type water turbines 21A and 21B, horizontal axis type water turbine 21C, vertical axis type water turbine 21D, etc. can be used. can.

Regarding the water turbine 21 in the wave energy recovery device 20B that recovers the potential energy of the towing wave Aw, the structure of the overtopping type power generation system proposed in the wave power generation system can be referred to. In this overtopping type power generation system, part of the water from the incoming waves is made to climb over a sloping plate and introduced into a water tank located higher than the surface of the water. is discharged from the discharge pipe above or below the water surface. When the water falls and is discharged, it rotates the turbine (propeller) and drives the generator to generate electricity. More specifically, this downward flow of water is received by an axial flow turbine such as a propeller, and the horizontal flow inside and outside the discharge pipe is received by an axial flow turbine, a cross flow turbine, a Darrieus turbine, or the like.

In addition, as these water turbines 21, micro-nano hydroelectric power generation (100 kW or less), mini hydro power generation (100 kW to 1000 kW), small hydro power generation equipment (1000 kW or less), etc. Water turbines such as gravity water turbines for 1 m to 5 m) can also be used as a reference. For example, a cross-flow water turbine having a rotation axis in a horizontal direction perpendicular to or intersecting the flow direction, a Darrieus water turbine rotating by utilizing the lift force of rotor blades, and the like can be referred to.

Although it is more special, as shown in FIG. 11, regarding the water conduit 22, a structure in which a part of the water conduit 22 is arranged above the water surface in the siphon water intake system can also be used as a reference. In this siphon water intake method, the inlet opening 22a is submerged at the crest of the wave, and the drain opening 22f is submerged at the trough of the wave. A main part of the water conduit 22 is arranged on the upper deck 3 or the like. Then, the vacuum pump 22i is used to exhaust the air in the conduit 22, suck up the water W, fill the conduit 22 with water W, and put the conduit 22 into a siphon state. Then, the water wheel 21 is arranged in this water conduit 22 . With this configuration, many parts of the water turbine 21 and the water conduit 22 can be arranged on the upper deck 3, which facilitates maintenance. In addition, since only the flexible pipe 22j connected to the inlet opening 22a and the flexible pipe 22k connected to the drain opening 22f need only be movable, the moving mechanism 32 can be miniaturized.

When part of the potential energy of the tug wave Aw is recovered, it is advantageous to lead a large amount of the water W flowing into the potential energy conversion device 21 to a higher position. Therefore, it is also important to convert part of the kinetic energy of the towing wave Aw into potential energy by devising the shape of the entrance opening 22a and the inclination angle of the front water conduit 22b, for example.

[Third Embodiment] A wave energy recovery device 20C of a third embodiment converts both kinetic energy and potential energy into rotational energy. In this case, both the water turbine 21 for recovering the kinetic energy and the water turbine 21 for recovering the potential energy are provided with the water conduit (water flow control mechanism) 22, or both the kinetic energy and the potential energy are applied to the inclined water conduit 22h. It may be configured with a water wheel 21 for recovery.

When both the water turbine 21 for kinetic energy and the water turbine 21 for potential energy are arranged, the water turbine 21 for kinetic energy is arranged in front, and after recovering the kinetic energy of the tug wave Aw, the flow velocity increases. The lowered water W is temporarily stored in the water storage part 22c arranged at the rear, and then guided to the water turbine 21 for potential energy.

When the separate water turbine 21 is arranged, as shown in FIG. 12, the wave energy recovery device 20A of the first embodiment and the wave energy recovery device 20B of the second embodiment are arranged in order. good too. The two wave energy recovery devices 20A and 20B are respectively unitized and configured, and are connected to each other in the front and rear or arranged close to each other. In this case, the water W whose kinetic energy has been reduced in the wave energy recovery device 20A has a lower flow velocity toward the rear, and the falling velocity component increases. , the inlet opening 22a of the water conduit 22 should be arranged to allow guidance to the wave energy recovery device 20B.

Further, as shown in FIG. 13, a water wheel 21 for kinetic energy may be arranged inside the front water channel 22b of the wave energy recovery device 20B. In this case, the structure is more complicated than the wave energy recovery device 20B, but the kinetic energy of the towing wave Aw can also be recovered, so the energy recovery efficiency is improved.

Furthermore, as shown in FIG. 14, the inclined channel 22h is provided with a water wheel 21 that recovers both kinetic energy and potential energy. By using one water turbine 21 for both purposes, two water turbines 21 become unnecessary and the structure is simplified.

Note that the water turbine 21 for kinetic energy and the water turbine 21 for potential energy used in this wave energy recovery device 20C may be different types of water turbines 21 in consideration of energy recovery efficiency. The water turbines 21 may be of the same type in consideration of maintenance simplification.

[Generating Device and Power Transmission Mechanism] Next, the power generating device 23 and the power transmission mechanism 24 will be described. The power generator 23 includes a generator that converts the rotational energy of the water turbine 21 into electrical energy. As this generator, reference can be made to generators used in tidal current power generation, wave overtopping power generation systems, small hydroelectric power generation, and the like. In addition, the electric motor of the pod propulsion is also helpful. In addition to the generator, the power generator 23 includes a power conversion device that converts the power from the generator between DC and AC and voltage, a power storage device that temporarily stores power, and an external power generator. It also includes a power supply device that supplies power to the

The power transmission mechanism 24 is a mechanism that transmits the rotational energy of the water turbine 21 to the generator. The transmission mechanism, etc. are helpful. In the present invention, the turning function in these power transmission mechanisms is useful for changing the angle of lateral inclination (yaw angle) β, but it is usually unnecessary, and the mechanism is simplified accordingly.

For example, in one Z drive, power to the propeller is transmitted from the rotating shaft of the prime mover through the propeller shaft, lower bevel gear, vertical shaft, upper bevel gear, and coupling. This two-stage bevel gear has the function of switching the direction of rotation of the propeller in addition to the function of a reduction gear that obtains the proper propeller rotation speed to increase the propulsion efficiency. The present invention eliminates the need for the function of switching the direction of rotation of the propeller.
It should be noted that although it is usually composed of a set of a gear and a rotating shaft, it may be a mechanism that utilizes fluid pressure, such as a combination of a hydraulic pump and a hydraulic motor that utilize fluid pressure.

Also, if the power transmission mechanism 24 is omitted and the wave energy recovery device 20 is provided with a generator 23 having a rotation shaft that is coaxial with the rotation shaft of the water turbine 21, the wave energy recovery system 10 can be configured very compactly. be able to In this configuration, the structure of the pod propulsion device containing the electric motor serves as a reference.

[Support Device] Next, the support device 30 will be described. The support device 30 is a device for supporting the wave energy recovery device 20 on the ship 1, and includes a support mechanism 31, and, if necessary, a moving mechanism 32, a housing mechanism 33, and the like.

[Support Mechanism] In this support mechanism 31, a vertical support member 31A, a horizontal support member 31B, an oblique support member 31C, etc. can be considered from the support direction. In the towing type wave energy recovery device 20, the towing rope 31D, the member to be towed 31E, etc. can be considered, but these will be described separately.

By configuring the vertical support member 31A to be extendable, the submersion depth of the wave energy recovery device 20 can be changed. Further, by configuring the horizontal support member 31B to be extendable, it is possible to change the distance between the wave energy recovery device 20 and the submerged portion 2 of the hull. Further, by constructing the oblique support member 31C so as to be able to expand and contract, it is possible to simultaneously change the submersion depth of the wave energy recovery device 20 and the separation distance between the wave energy recovery device 20 and the submerged portion 2 of the hull.

In addition, by providing the submerged portion of the support mechanism 31 with buoyancy, lift, or sinking force that offsets the weight of the wave energy recovery device 20, the influence of the installation and movement of the wave energy recovery device 20 on the attitude of the hull can be reduced. can be made smaller.

On the other hand, if the portion of the vertical support member 31A that penetrates the water surface is given buoyancy, it will be possible to generate a restoring force when the ship 1 rolls or heels. This has the advantage of increasing stability. On the other hand, when adding to the existing ship 1 already in service, the restoring force generated by the vertical support member 31A is a non-designed restoring force, so the generation of the restoring force by the vertical support member 31A is excluded. In this case, a ballast tank can be provided inside the vertical support member 31A to neutralize the buoyancy of the vertical support member 31A, thereby preventing the generation of the restoring force.

In addition, when the vertical support member 31A having a submerged portion is used, as a secondary effect, a turning moment is generated due to the shape of the horizontal cross section of the submerged portion of the vertical support member 31A and the flat provided in the submerged portion. By configuring so as to be able to do so, the course keeping performance and turning performance of the ship 1 can be improved.

In addition, when using the horizontal support member 31B having a submerged portion, as a secondary effect, the shape of the vertical cross section of the horizontal support member 31B, flatness, etc. are configured to generate a trim moment (pitch moment). By doing so, it is possible to improve posture (trim) maintenance performance and pitching suppression performance.

When the oblique support member 31C having a submerged portion is used, the effect of the vertical support member 31A and the horizontal support member 31B can be exhibited as a secondary effect. becomes a little more complicated.

[Movement Mechanism] In the wave energy recovery system 10, the position (x, y, z) of the wave energy recovery device 20 with respect to the vessel, or the vertical inclination angle (pitch angle) α or the lateral inclination angle (yaw angle) β It is configured with a moving mechanism 32 that changes at least one. In other words, the wave energy recovery device 20 is configured to be movable in at least one of the longitudinal direction X, the width direction Y, and the vertical direction Z. Preferably, the vertical inclination angle (pitch angle) α Alternatively, one or both of the angle of lateral inclination (yaw angle) β can be changed.

More specifically, regarding the moving mechanism 32 , the shape of the hull submerged portion 2 changes as the load condition of the ship 1 changes. In other words, when the loaded state becomes a light load state and the draft becomes shallow, the height of the tow wave Aw generally becomes low relative to the ship 1, so it is necessary to lower the position of the wave energy recovery device 20. . On the other hand, when the ship is fully loaded and the draft becomes deep, the height of the tug wave Aw generally becomes higher than the ship 1, so the position of the wave energy recovery device 20 needs to be raised.

Since it is considered that the wave energy of the tug wave Aw is often larger in the full load state than in the light load state, when the wave energy recovery device 20 is fixedly arranged, it is mainly arranged in the full load state. However, when the load condition when the tug wave Aw passes through the problematic route is almost determined, the wave energy recovery device 20 is fixedly arranged mainly based on the load condition. In this case, if the ship becomes lightly loaded, the wave energy recovery device 20 will be above the surface of the water, depending on the change in the draft of the ship.

On the other hand, when the wave energy recovery device 20 is mainly installed in a lightly loaded state, the wave energy recovery device 20 may be submerged in the fully loaded state to increase the propulsion resistance, or the wave energy recovery device 20 may be submerged. As the water depth increases, the wave energy recovery efficiency decreases, so the wave energy recovery device 20 must be configured to be movable in the vertical direction Z.

Then, in the ship 1, when the sailing speed Vs changes, the wave pattern of the tug wave Aw changes, and the positions of crests and troughs of the waves also change. As the sailing speed Vs increases, the wavelength becomes longer and the immersion depth where wave energy exists becomes deeper. Therefore, when recovering the wave energy of the tug wave Aw for a specific sailing speed Vs, the arrangement position in the longitudinal direction X and the arrangement position in the vertical direction Z of the wave energy recovery device 20 may be fixed. When recovering the wave energy of the tug wave Aw while following the change in the sailing speed Vs, the arrangement position of the wave energy recovery device 20 in the longitudinal direction X and the arrangement position in the vertical direction Z can be made movable. preferable.

[Accommodation Mechanism] In the wave energy recovery system 10, the accommodation mechanism 33 is also provided for partially or entirely accommodating the wave energy recovery device 20 inside the hull of the ship 1 or on the upper deck 3 or above the upper deck 3. mechanism. As a result, it is possible not to interfere with the berthing work of the ship 1 or the towing work by the tugboat.

The storage mechanism 33 can accommodate the wave energy recovery device 20 by rotating it from above on a part of the side surface of the ship 1 and positioning it horizontally. overturning method in which the wave energy recovery device 20 is folded and moved onto the recess of the ship 1 or on the upper deck 3, a telescopic method in which the wave energy recovery device 20 is expanded and contracted sideways from a part of the side of the ship 1, a lifting method in which it is lowered from the upper deck, and other Various methods such as methods can be used.

Further, as illustrated in FIGS. 15 to 19, the wave energy recovery device 20 may be configured to be moved within the transverse plane (in the YZ plane), or may be configured to recover the wave energy within the vertical plane (in the ZX plane). The device 20 may be moved, or the wave energy recovery device 20 may be moved in the horizontal plane (in the XY plane). As this storage method, the storage method of the wheels of an aircraft can be referred to. 15 to 19 exemplify the axial-flow type water turbine 21A as a part of the wave energy recovery device 20, the wave energy recovery device 20 using other water turbines 21 may be used.

In the rotating method, as shown in FIG. 15, the oblique support member 31C of the wave energy recovery device 20 is rotated around the rotation shaft 33a in the accommodation mechanism 33, thereby moving the wave energy recovery device 20 to the upper deck 3. Move between stowed and deployed positions. 16 and 17, the horizontal support member 31B of the wave energy recovery device 20 is partially provided with the rotation shaft 33a of the housing mechanism 33, and the horizontal support member rotates around the rotation shaft 33a. By rotating 31B, the wave energy recovery device 20 is moved between the accommodation position and the arrangement position on the concave portion 2h of the side 2c (Fig. 16) or on the upper deck 3 (Fig. 17).

In the expansion/contraction method, the horizontal support member 31B is expanded/contracted by expanding/contracting the piston 33b in the accommodation mechanism 33 as shown in FIG. Move between position and placement position. In the elevating method, as shown in FIG. 19, the wave energy recovery device 20 is moved up and down on the upper deck 3 by raising and lowering the wave energy recovery device 20 along the elevating column 33d using the housing mechanism 33. between stowed and deployed positions.

Further, part or all of the wave energy recovery device 20 may be configured to be movable together with the accommodation mechanism 33 , or may be configured to be capable of accommodating part or all of the wave energy recovery device 20 together with the movement mechanism 32 . Alternatively, part or all of the wave energy recovery device 20 may be moved to a specific accommodation position and then accommodated.

[Non-accommodation of wave energy recovery device] Apart from the above configuration, the non-accommodation method of the wave energy recovery device 20 is employed in ships that do not necessarily need to be berthed. These ships include cargo ships and other ships that do not allow passengers to get on and off, especially tankers that do not stop at a port and load and unload offshore berths, and large passenger ships that are difficult to berth due to their large size and pass between piers. etc. Also, in the case of a ship where it is sufficient to secure a passage for personnel and supplies between the pier, wharf, or the like and the ship, it is possible to cope with this by building a bridge between the two.

Further, when the side where the ship 1 berths is determined, the wave energy recovery device 20 on the side not berthed does not necessarily have to be configured to be accommodated. In addition, when berthing, it is not always necessary to berth the submerged part 2 of the hull, and it is only necessary to secure a passage for personnel and supplies. A non-accommodating method in which the energy recovery device 20 is left unaccommodated may be employed. This non-accommodation method can be adopted for commercial ships such as cargo ships that do not have passenger boarding and disembarking, especially for tankers that do not stop at a port and carry out cargo at offshore berths.

[Towed Wave Energy Recovery Device] Next, the towed wave energy recovery device 20 will be described. As shown in FIGS. 20 and 21, this towing type wave energy recovery device 20 is provided on a member 31E to be towed by a towline 31D extending from a towing device (supporting device) 30 provided on the ship 1. The wave energy recovery device 20 is fixedly supported by a support member 31Ec connected to a hull 31Ea functioning as a buoyant body.

In this tow-type wave energy recovery device 20, the position in the longitudinal direction X with respect to the vessel 1 can be set by the length of the towline 31D extending from the deck of the hull 31Ea. When the wave energy recovery device 20 is arranged near the side 2c of the hull 31Ea, the lateral force generation member 31Ed extending in the vertical direction Z in the water on the side of the hull 31Ea is used to move the hull 31Ea toward the side of the ship 1 during towing. Generate a force Fy. As a result, the separation distance from the ship 1 in the width direction Y can be maintained by pressing the tip of the separation distance maintaining member 31Eb arranged on the side of the hull 31Ea against the side 2c of the ship 1 . On the other hand, when the wave energy recovery device 20 is arranged at a position away from the side 2c, the separation distance from the ship 1 can be maintained by projecting the towing point of the ship 1 from the side 2c. Further, a lateral force Fy that draws the hull 31Ea toward the ship 1 during towing is generated in a direction away from the side 2c of the ship 1, and a mooring cable extending laterally from the side 2c of the ship 1 is added to the towed member 31E. The distance from the ship 1 can be maintained by the length of the additionally installed mooring cable.

This towed wave energy recovery device 20 requires a towed member 31E, but the support mechanism 31, the moving mechanism 32, and the storage mechanism 33 have a very simple configuration, and are separate from the ship 1. can be formed. Therefore, the amount of construction required for the ship 1 is small, and the entire wave energy recovery system 10 can be simplified. In addition, the towed wave energy recovery device 20 has the advantage of being easy to unitize and standardize.

[Control Device] Next, the control device 40 will be described. The control device 40 is a device for controlling the entire wave energy recovery system 10, and may be arranged integrally with the wave energy recovery system 10. The control device 40 may may be arranged on the bridge of the bridge or the like, or may be arranged on both sides so that they can be selected and controlled.

When the wave energy of the tug wave Aw is to be recovered, the control device 40 controls the accommodation mechanism 33 to take out the wave energy recovery device 20 from a predetermined accommodation position, move the support mechanism 31 of the support device 30, and move it. Mechanisms 32 and the like are controlled by controller 40 to position wave energy recovery device 20 in the recovery position. Further, when changing the recovery position of the wave energy recovery device 20 by following the change in the wave pattern of the tug wave Aw, the control device 40 controls the support mechanism 31 and the moving mechanism 32 of the support device 30. , to change the collection position.

Furthermore, the control device 40 controls the water flow control mechanism (water channel) 22, and if necessary, the guide member 5 provided in the ship 1 described later, etc., to further improve the recovery efficiency. Aw is directed to the wave energy recovery device 20 . In addition, while controlling the power transmission mechanism 24 by the control device 40 as necessary, the rotation speed of the energy conversion device (water turbine) 21 and the rotation speed of the power generation device (generator) 23 are controlled, and the amount of power generation and wave energy are controlled. Adjust the collection amount.

When the wave energy of the tug wave Aw is not to be recovered, the control device 40 controls the housing mechanism 33 of the support device 30 to house the wave energy recovery device 20 at a predetermined housing position.

[Vessel] Next, a vessel 1 (1A, 1B) according to an embodiment of the present invention will be described. This ship 1 is configured with any of the wave energy recovery systems 10 for ships described above.

The ship 1A of the first embodiment is configured by equipping the conventional ship 1A with the wave energy recovery device 20 system 10 . An example of a ship 1A of this first embodiment is shown in FIG. Further, the ship 1B according to the second embodiment of the present invention is a ship 1B having a stern with a symmetrical wing shape as the hull shape of the other ship 1 equipped with the wave energy recovery system 10 . FIG. 23 shows an example of a ship 1B having this symmetrical wing-shaped stern.

In the ship 1B of this second embodiment, as shown in FIG. Below the waterline WL, in at least 50% of the range in the depth direction, 70% of the waterplane shape is continuously or intermittently formed by the shape Swing of the rear half Rbw of the symmetrical wing 60 In other words, 70% of the water plane shape of the rear half Rbs of the submerged portion 2 of the hull is configured to match 70% of the shape Swing of the rear half Rbw of the symmetrical wing.

More specifically, in FIG. 23A, the rear half Rbs of the submerged hull portion 2 of the ship 1B (behind the center Pm in the longitudinal direction X of the submerged hull portion 2) is a symmetrical wing (“NACA0020 wing”). An example in which the rear half portion Rbw (behind the center Pm in the longitudinal direction X of the symmetrical blade 60) is formed in the shape Swing is shown. In addition, FIG. 23(b) shows the entire symmetrical blade (“NACA0020 blade”) 60 . Further, the symmetrical blade 60 is not limited to this "NACA0020 blade", and may be other symmetrical blades.

According to the configuration of the ship 1B of the second embodiment, most of the rear half Rbs of the submerged portion 2 of the hull is formed in the Swing shape of the rear half Rbw of the symmetrical wing, so the flow on the stern side can be simplified. , rear shoulder and stern wave generation can be suppressed. Therefore, the wave energy of the tow waves Aw generated in the rear half Rbs of the submerged portion 2 of the hull can be reduced, and the stern wave component of the tow waves Aw can also be reduced. As a result, in addition to the effect of reducing the tug wave Aw by the wave energy recovery system 10, the stern wave component of the tug wave Aw can also be reduced. The wave-making resistance as a whole can be greatly reduced.

[Arrangement of Wave Energy Recovery Device] In these ships 1, the wave energy recovery device 20 is placed at a position on the side of the submerged portion 2 of the hull when the ship 1 is sailing at least in the forward direction X. It is configured to be arranged away from the surface of the portion 2 or in contact with the surface of the submerged portion 2 of the hull.

It should be noted that the phrase "separated from the surface of the submerged portion 2 of the hull" means a structure in which water (seawater, etc.) flowing outside the submerged portion 2 of the hull flows between the submerged portion 2 of the hull and the wave energy recovery device 20. is. In other words, there is a clearance between the surface of the submerged portion 2 of the hull and the wave energy recovery device 20, and the wave energy recovery device 20 and the submerged portion 2 of the hull are continuous. For example, unlike the bulging structure or projecting structure of the submerged portion 2 of the hull, the structure is not integrated with the submerged portion 2 of the hull.

Therefore, in the case of a configuration in which the water turbine 21 is exposed and does not have a water turbine with a duct (including other than the axial water turbine with a duct 21B) and the introduction passage 22, this configuration is inevitably adopted. Even in a configuration including a water turbine with a duct (including other than the axial water turbine with a duct 21B) and a water conduit 22, if the duct and the water conduit 22 are separated from the surface of the submerged portion 2 of the hull, the separation will be placed as follows. With this configuration, the wave energy recovery device 20 can be easily retrofitted to an existing ship, and the wave energy recovery device 20 can be easily moved.

In addition, the term “in contact with the surface of the submerged portion 2 of the hull” means a configuration including a water turbine with a duct (including other than the axial water turbine with a duct 21B) and a water conduit 22, and the duct and the water conduit 22 are connected to the hull. It means a structure in contact with the surface of the submerged portion 2 . It may have a structure integrated with the submerged portion 2 of the hull, or may have a structure separate from the submerged portion 2 of the hull and may be arranged in contact with the submerged portion 2 of the hull.

In this configuration, the duct or water conduit 22 is fixed to the submerged portion 2 of the hull, or a part or all of the duct or water conduit 22 protrudes or protrudes from the submerged portion 2 of the hull. including configurations that are This configuration is suitable for ships that can easily narrow down the conditions for wave energy recovery (loading state, sailing speed, etc.), and the wave energy recovery device 20 can be firmly fixed to the submerged portion 2 of the hull, so that the support structure can be simplified. .

Next, the relationship between the arrangement of the wave energy recovery device 20 and the wave pattern will be described. FIG. 24 shows an example of arrangement of the ship 1 with respect to the bow wave system, and FIG. 25 shows an example of arrangement of the ship 1 with respect to the stern wave system. As shown in FIGS. 24 and 25, the wave energy recovery device 20 at least measures the tug wave Aw generated when the ship 1 (the ship 1A in FIGS. 24 and 25) is sailing in the forward direction X. of the fan-shaped region Rca inside the cusp line Lap that opens at one side angle θc (about 20 degrees: theoretically 19 degrees 28 minutes) in the horizontal direction Y with the tug wave generation source Awp as the vertex for the wave pattern of placed inside.

By arranging the wave energy recovery device 20 inside the fan-shaped region Rca, the arrangement position of the wave energy recovery device 20 can be easily set. In addition to the cusp Pac(i) on the cusp line Lap, the intersection of the crest line Lwc of the longitudinal wave Awc and the crest line Lwd of the transverse wave Awd also becomes a peak of the tow wave Aw. , the position of the crest of the tug wave Aw can be specified, and the position of the crest can be used as a guideline for the arrangement of the wave energy recovery device 20 .

Although FIGS. 22 to 25 do not show a propulsion system such as a propeller, water jet propulsion device, or pod propulsion device, the wave energy recovery system 10 of the present invention can be used regardless of the shape of the submerged portion 2 of the hull. Also, since the wave energy of the tow waves Aw is recovered regardless of the propulsion system, it can be applied to any ship 1 (1A, 1B) that generates the tow waves Aw.

[Guiding member] Further, in order to improve the recovery efficiency of the wave energy recovery device 20, the ship 1 includes guide fins 5A (Figs. 26, 28, and 29) for guiding the tug wave Aw to the wave energy recovery device 20. Alternatively, it is preferable to have a guide member 5 composed of a guide plate 5B (FIGS. 27 to 29).

The guide fins 5A, which are the first type of the guide member 5, guide the flow of the water W of the tug wave Aw in the vertical direction Z to the water turbine 21 so that the recovery efficiency in the water turbine 21 is high. Usually, a member having a wing-shaped cross section is arranged by extending outward in the width direction Y from the shipboard side 2c. The guide fins 5A may be fixedly arranged on the ship 1, but preferably configured so that the angle of attack (pitch angle) can be changed so as to follow changes in the waveform of the tug wave Aw. The guiding fins 5A are arranged in front of the water turbine 21 (FIG. 26), in front of the inlet opening 22a of the water conduit 22, and the like. A blade end plate 5Ab (FIG. 29) extending in the vertical direction Z is provided at the outer end of the main wing 5Aa of the guide fin 5A so as to control the flow of the water W of the tug wave Aw in the width direction Y as well. good too.

In addition, the guide plate 5B, which is the second type of the guide member 5, also guides the flow of the water W of the towing wave Aw in the vertical direction Z or the width direction Y to the water turbine 21 so that the recovery efficiency in the water turbine 21 is high. can be guided more strongly than the guiding fin 5A. On the other hand, the provision of the guide plate 5B increases the propulsion resistance generated. Normally, as illustrated in FIGS. 27 and 28 , a plate-shaped member is extended outward in the width direction Y from the shipboard side 2 c of the ship 1 and arranged over a certain range in the longitudinal direction X. Alternatively, as shown in FIG. 29, a plate-shaped member is spaced apart from the shipboard side 2c of the ship 1 and extended in the up-down direction Z to cover a certain range in the front-back direction X. As shown in FIG. The guide plate 5B is arranged at a position in front of the water wheel 21 (FIGS. 27 to 29), a position at the water wheel 21, a position behind the water wheel 21, a position in front of the inlet opening 22a of the water conduit 22, and the like.

These guide members 5 are configured separately from the water flow control mechanism 22 of the wave energy recovery device 20 . While the water flow control mechanism 22 is fixed to the wave energy recovery device 20 separately from the ship 1 and moves together with the wave energy recovery device 20, the guide member 5 is provided integrally with the ship 1. . The guide member 5 and the water flow control mechanism 22 are complementary to each other, and may be provided with only one or both.

These guide members 5 may be of a single type, or may be used in combination of several types. Further, a plurality of guide members 5 of a single type may be arranged in the up-down direction Z or in the front-rear direction X. FIG. These guide members 5 are arranged in the existing area of the tug wave Aw (inside the wave pattern). As for the guide plate 5B, the front end of the guide plate 5B may be arranged in the area where the tow waves Aw exist, and the other parts do not necessarily need to be inside the area where the tow waves Aw exist. There may be.

The water wheel 21 is arranged behind the guide fins 5A or the guide plate 5B. According to the configuration including these guide members 5, the guide members 5 can guide the tug wave Aw to the wave energy recovery device 20, thereby increasing the amount of recovered energy.

[Method for reducing tow waves on a ship] In the method for reducing tow waves for a ship according to the first embodiment of the present invention, at least when the ship 1 is sailing in the forward direction X, both sides of the ship 1 or Part of the wave energy of the towing wave Aw generated by the submerged portion 2 of the hull 1 of the ship 1 is recovered by the wave energy recovery device 20 disposed behind or in contact with the surface of the hull of the ship 1. , a method for reducing the wave energy of the tug wave Aw generated by the ship 1 .

Alternatively, a ship tug wave reduction method according to the second embodiment of the present invention is a method of reducing wave energy of tug wave Aw of the ship 1 using any of the wave energy recovery systems 10 for ships described above. is. According to this ship tug wave reduction method, the tug wave Aw generated from the ship 1 can be reduced by recovering part of the wave energy of the tug wave Aw with an energy conversion device such as the water turbine 21 .

[Method for reducing wave-making resistance of ship] Then, using the wave energy recovery system 10 of the present invention or the tug wave reduction method of the present invention, part of the wave energy of the recovered tug wave Aw is converted into electric energy or the like. , the wave-making resistance of the ship 1 can be substantially reduced by using it as part of the propulsion energy of the ship 1 . However, in order to obtain the effect of reducing the propulsion resistance of the ship 1, it is necessary to increase the propulsion resistance due to the arrangement of the wave energy recovery system 10, increase the wake due to the recovery of part of the wave energy, and reduce the propulsion resistance due to changes in the water flow. The increase requires a greater amount of wave energy to be recovered by the wave energy recovery system 10 .

[Method for Remodeling Ship] The method for remodeling a ship according to the embodiment of the present invention is a method for additionally providing any of the wave energy recovery systems 10 for ships described above to an existing ship 1 . According to this method, the same effects as those of the methods for reducing tow waves for ships described above can be exhibited.

[Effects of the Present Invention] According to the wave energy recovery system 10 for a ship, the ship 1, the tow wave reduction method for a ship, etc., regardless of the shape of the hull including the shape of the bow, the hull submerges. Part of the wave energy can be recovered from the tow waves Aw generated by the submerged portion 2, particularly from the bow wave Aw generated by the front half of the submerged portion 2 of the hull. .

1 Vessel 2 Hull submerged portion 2a Bow 2c Broadside 2d Ship bottom 3 Upper deck 5 Guide member 5A Guide fin (guide member)
5B induction plate (induction member)
10 wave energy recovery system 20 wave energy recovery device 21 water wheel (energy conversion device)
21A Axial flow turbine (converter)
21B Ducted axial water turbine (converter)
21Ba Propeller 21Bb Duct 21C Horizontal axis water turbine (conversion device)
21D vertical axis water turbine (converter)
22 water channel (water flow control mechanism)
22a inlet opening 22b front water channel 22c water reservoir 22d vertical water channel 22e horizontal drainage channel 22f drainage opening 22g air vent 22h inclined channel 22i vacuum pump 23 generator (power generating device)
24 Power transmission mechanism 30 Support device 31 Support mechanism 31A Vertical support member 31B Horizontal support member 31C Oblique support member 31D Towing rope 31E Towed member 32 Moving mechanism 33 Accommodating mechanism 40 Control device 60 Target wing Aw Towing wave Awc Longitudinal wave Awd Lateral wave Awp Tow wave source Bc Vessel width (high-speed container ship)
Bt Vessel width (VLCC)
Bd Width (escort ship)
Bmax Maximum hull width Lac Route of tow wave generation source Lap Cuspline Lc Hull center line (hull center plane)
Lwc Wave crest line of longitudinal wave Lwd Wave crest line of transverse wave Pac(i) Cusp Pm Center of submerged portion of hull in longitudinal direction Rbs Rear half of submerged portion of hull Rca Fan-shaped region Swing Shape of rear half of symmetrical wing Va Towing wave Proceeding speed of source Vs Sailing speed W Water WL Still water surface (draft during sailing)
X longitudinal direction (front-back direction of the ship), forward direction Y width direction (width direction of the ship)
Z vertical direction (vertical direction of the ship)
θ Angle of propagation direction of wave θc Angle of cuspline

Claims (14)

A wave energy recovery system (10) installed in a vessel (1) that generates a tow wave (Aw) during cruising, at least when the vessel (1) is cruising in a forward direction (X). A tug wave (Aw) generated by a submerged hull (2) of the ship (1) disposed at a location where the tug (Aw) exists or a location where the tug (Aw) is guided. A wave energy recovery system for a ship, characterized in that it recovers a portion of the wave energy of a ship. The wave energy recovery device (20) is a water wheel (21) that converts part of the kinetic energy of the tug (Aw) into rotational kinetic energy, or rotates part of the potential energy of the tug (Aw). A water wheel (21) that converts into kinetic energy, or a water wheel (21) that converts both part of the kinetic energy and part of the potential energy of the tug wave (Aw) into rotational kinetic energy. 2. A wave energy recovery system for a marine vessel according to claim 1. The water turbine (21) is an axial flow type water turbine (21A) in which the rotation axis is arranged in the direction of wave flow or in the longitudinal direction (X) of the ship, or a horizontal axis type in which the rotation axis is arranged in the horizontal direction (Y). 3. A wave energy recovery system for ships according to claim 2, characterized in that the water turbine is either a water turbine (21B) or a vertical axis type water turbine (21D) whose axis of rotation is arranged in the vertical direction (Z). The wave energy recovery device (20) comprises a duct (21Bb) covering the water turbine (21) or a water conduit (22) for introducing water (W) to the water turbine (21). A wave energy recovery system for a marine vessel according to claim 2 or 3. A moving mechanism ( 32). A wave energy recovery system for a marine vessel according to any one of claims 1 to 4, characterized in that it comprises: A part or all of the wave energy recovery device (20) is provided with an accommodation mechanism (33) for accommodation inside the hull or the upper deck (3) of the ship (1) or above the upper deck (3). A wave energy recovery system for ships according to any one of claims 1 to 5, characterized in that: A wave energy recovery system for ships according to any one of claims 2 to 4, characterized in that the wave energy recovery device (20) is adapted to be towed by the ship (1). . Ship, characterized in that it comprises a wave energy recovery system (10) for ships according to any one of the preceding claims. The wave energy recovery device (20) is placed at a position on the side of the submerged portion (2) of the hull from the surface of the submerged portion (2) of the hull while sailing at least in the forward direction (X). 9. Ship according to claim 8, characterized in that it is arranged at a distance or against the surface of the hull submerged part (2). A guiding member (5) comprising a guiding fin (5A) or a guiding plate (5B) that guides part or all of the towing wave (Aw) to the wave energy recovery device (20) is provided. The vessel according to claim 8 or 9. The rear half (Rbs) of the submerged portion (2) of the hull is continuous or intermittent in a range of at least 50% in the depth direction below the full load line or the planned waterline with respect to the vertical direction (Z) of the ship. A ship according to any one of claims 8 to 10, characterized in that 70% of the water plane shape is formed in the shape (Swing) of the rear half (Rbw) of the symmetrical wing. Wave energy spaced apart from or in contact with the hull surface of said vessel (1) on either side or aft of said vessel (1) at least when said vessel (1) is sailing in the forward direction (X). The vessel (1) is generated by recovering part of the wave energy of the tug wave (Aw) generated by the submerged portion (2) of the vessel (1) by means of a recovery device (20). A method for reducing tow waves on a ship, characterized by reducing the wave energy of tow waves (Aw). A ship, characterized in that the wave energy recovery system (10) for ships according to any one of claims 1 to 7 is used to reduce the wave energy of the tow waves (Aw) of said ship (1). tug wave reduction method. A method of retrofitting a ship, characterized in that a wave energy recovery system (10) for a ship according to any one of claims 1 to 7 is additionally installed in an existing ship (1).

Images