JP6922646B2 - Buoyancy compensator and buoyancy compensator - Google Patents

Description

The present invention relates to a buoyancy compensator and a buoyancy compensator system.

Patent Document 1 discloses a buoyancy compensator applied to an underwater floating type underwater device. This buoyancy compensator controls buoyancy by adjusting the amount of water and air in the ballast tank.

International Publication 2014/16341

Underwater floating equipment may repeatedly increase or decrease buoyancy in order to maintain its position (specifically, depth) in water. The increase / decrease in buoyancy is performed, for example, by adjusting the ratio of water and gas provided to the buoyancy compensator, as disclosed in Patent Document 1. Here, as for water, water existing around the underwater equipment can be used. On the other hand, since gas cannot be obtained from the surroundings like water, the gas filled in a tank or the like is used or supplied from the outside of an underwater device. In such an operation, there is a limit to the repeated increase and decrease of buoyancy. Therefore, in the art, a buoyancy compensator and a buoyancy compensator capable of continuously performing an operation of repeatedly increasing and decreasing the buoyancy have been desired.

The present invention provides a buoyancy compensator and a buoyancy compensator capable of continuously performing an operation of repeatedly increasing or decreasing buoyancy.

The buoyancy adjusting device, which is one embodiment of the present invention, forms an internal space having a predetermined volume, and is housed in a tank portion including a gas chamber filled with gas in the internal space and in the internal space in the internal space. It includes a bag portion that forms a liquid chamber separated from the gas chamber, and a control unit that controls water injection of the liquid into the liquid chamber and drainage of the liquid from the liquid chamber.

Since the buoyancy compensator has a predetermined volume, the buoyancy compensator controls the apparent buoyancy based on the buoyancy in a narrow sense caused by the volume and the gravity caused by the weight of the buoyancy compensator. Here, the tank portion has a predetermined volume, and the volume does not change. On the other hand, the weight of the buoyancy compensator can be increased or decreased depending on the amount of liquid accepted in the bag portion. Therefore, the buoyancy compensator can control the apparent buoyancy by controlling the amount of liquid received in the bag. That is, where the buoyancy is constant, the weight of the buoyancy compensator increases due to the acceptance of the liquid. Therefore, the apparent buoyancy of the buoyancy compensator can be reduced. On the other hand, it is also possible to drain the liquid from the bag portion. Then, where the buoyancy is constant, the weight of the buoyancy compensator is reduced by the drainage of the liquid. Therefore, the apparent buoyancy of the buoyancy compensator can be increased. According to this configuration, in the control of buoyancy, only the liquid needs to be provided or drained to the buoyancy compensator, and gas is not consumed. Therefore, the buoyancy compensator can continuously perform an operation of repeatedly increasing or decreasing the buoyancy.

In one form, the tank portion has a cylindrical shape with a pair of end walls and a tubular side wall connecting the pair of end walls, the side wall has an opening, and the bag portion is fixed to the side wall. It may also have a water supply / drainage section through which the opening is inserted. According to this configuration, when the buoyancy compensator is mounted on an underwater device, it can be mounted so that the axial direction of the tank portion faces the horizontal direction. Then, it is possible to increase the volume occupied by the buoyancy compensator in the space formed by the casing of the underwater device. Therefore, the amount of apparent buoyancy control that can be controlled by the buoyancy compensator can be expanded.

In one form, the tank portion may have a first connecting portion that connects one end wall and the bag portion, and a second connecting portion that connects the other end wall and the bag portion. According to this configuration, when the buoyancy compensator is tilted at an angle, it is possible to prevent the bag portion from being biased downward due to the weight of the liquid contained therein. Then, it is possible to suppress the load from acting on the water supply / drainage portion of the bag portion fixed to the side wall.

In one form, the length of the first connecting portion may be shorter than the length from one end wall to the water supply / drainage portion. According to this configuration, the end portion of the bag portion to which the first connecting portion is connected does not move to the other end wall side of the water supply / drainage portion. Therefore, it is possible to reliably suppress the load from acting on the water supply / drainage section.

In one form, the control unit may include a valve. According to this configuration, it is possible to control the injection of liquid into the bag portion using water pressure and the drainage of liquid from the bag portion using the atmospheric pressure in the gas chamber.

In one form, the control unit may include a pump. According to this configuration, it is possible to control the injection and drainage of the liquid into the bag portion without being influenced by the water pressure received by the buoyancy compensator and the air pressure in the gas chamber.

The buoyancy adjusting system, which is another embodiment of the present invention, includes the above-mentioned buoyancy adjusting device and an integrated control unit that provides a control signal to the control unit of the buoyancy adjusting device. According to this system, it is possible to control the apparent buoyancy generated by each buoyancy compensator. Therefore, it is possible to provide buoyancy according to the demand of an underwater device equipped with a buoyancy adjustment system.

According to the present invention, there is provided a buoyancy adjusting device and a buoyancy adjusting system capable of continuously performing an operation of repeatedly increasing or decreasing the buoyancy.

FIG. 1 is a perspective view showing a power generation system to which the buoyancy compensator according to the first embodiment is applied. FIG. 2 is a diagram showing a configuration of a buoyancy compensator. FIG. 3 is a diagram for explaining the principle of the buoyancy compensator. Part (a) of FIG. 4 is a diagram showing the operation of the buoyancy compensator according to the first embodiment, and part (b) of FIG. 4 is a diagram showing the operation of the buoyancy compensator according to the second embodiment.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted. Further, in the following description, the terms "upstream" and "downstream" are used with reference to the flow of water. Further, the word "before" means the upstream side of the water flow, and the word "after" means the downstream side of the water flow. For example, when a downwind turbine is used, blades are placed on the rear side of the pod.

<First Embodiment>
As shown in FIG. 1, the power generation system 1 has a power generation device 2 and a mooring structure 3. The underwater floating power generation device 2 is moored to the seabed WB by the mooring structure 3 and is arranged at a predetermined water depth. The power generation device 2 is installed in seawater, for example, floats, and generates power by using the ocean current FL.

The power generation device 2 has a pair of pods 4 and a cross beam 6. The pair of pods 4 are arranged so as to be separated from each other on the left and right, and are connected to each other by a cross beam 6. The cross beam 6 has a predetermined length in the front-rear direction and a predetermined thickness. The cross beam 6 has, for example, a wing shape. According to the cross beam 6 having such a shape, the posture of the pod 4 can be stabilized. The left and right ends of the cross beam 6 are fixed to, for example, substantially the center of the body of the pod 4.

The pair of pods 4 have a similar configuration to each other. The cylindrical pod 4 has a turbine 7. The turbine 7 is provided at the rear of the pod 4. The turbine 7 has a blade 8, and the blade 8 receives the ocean current FL to rotate the rotation shaft of the turbine 7. The pod 4 provides an appropriate buoyancy to the turbine 7 while supporting the turbine 7. This buoyancy is provided by the buoyancy compensator 10 according to the embodiment.

The turbine 7 applied to the power generation device 2 is a so-called downwind type. The turbine 7 may be an upwind type turbine. The pod 4 floats in a posture facing the direction of the ocean current. In this floating state, the rotation axis of the turbine 7 is maintained substantially horizontal.

The power generation device 2 is connected to the anchor 9 via a mooring structure 3. The anchor 9 is a support fixed to the seabed WB. As the support tool, a sinker may be used instead of the anchor 9. The mooring structure 3 has a mooring line 3a and a power transmission cable 3b. The mooring line 3a mechanically connects the power generation device 2 to the anchor 9. The power transmission cable 3b is provided along the mooring line 3a and transmits electric power from the power generation device 2 to the anchor 9.

The power generation system 1 first supplies seawater to the buoyancy compensator 10 when the pod 4 is floating on the sea. Next, the power generation system 1 matches gravity and buoyancy by draining a part of the seawater in the buoyancy compensator 10 when the pod 4 has settled to a predetermined water depth. This control maintains the water depth of the pod 4. The pod 4 floats in the sea in a posture facing the direction of the ocean current FL. Then, the turbine 7 rotates in response to the ocean current FL to generate electricity. When the turbine 7 rotates and a thrust is generated, the mooring line 3a becomes tense and the force acts so that the pod 4 sinks. Here, when the ocean current FL is weak, the rotational speed of the turbine 7 is low and the thrust generated is also small. Therefore, the pod 4 floats at a shallow water depth. On the other hand, when the ocean current FL is strong, the rotational speed of the turbine 7 increases and the generated thrust also increases, so that the pod 4 sinks and floats at a deep depth.

For the above reasons, when the strength of the ocean current FL changes, the floating position of the pod 4 changes. At this time, the power generation system 1 adjusts the buoyancy by the buoyancy compensator 10 to raise or settle the pod 4 to a predetermined floating position. For example, when the strength of the ocean current FL increases and the rotational speed of the turbine 7 increases, the pod 4 tends to settle. Therefore, in order to suppress the sedimentation of the pod 4, the buoyancy is increased by the buoyancy compensator 10. On the other hand, when the strength of the ocean current FL becomes weak and the rotation speed of the turbine 7 decreases, the pod 4 tends to ascend. Therefore, in order to suppress the buoyancy of the pod 4, the buoyancy compensator 10 reduces the buoyancy. By controlling the buoyancy generated by the buoyancy compensator 10 according to the rotational speed of the turbine 7 (that is, the strength of the ocean current FL) in this way, the floating position of the pod 4 can be easily kept at an appropriate position.

Further, in the power generation system 1, a buoyancy compensator 10 is provided on each of the pair of left and right pods 4. Therefore, it is possible to control the posture of the pod 4 by adjusting the injection and drainage of the buoyancy compensator 10. For example, the water in each buoyancy compensator 10 is adjusted so as to increase or decrease the buoyancy as a whole while balancing the buoyancy of the left and right pods 4. According to this control, the pair of left and right pods 4 can be raised and lowered while being kept horizontal.

Next, the buoyancy compensator 10 will be described in detail.

As shown in FIG. 2, the buoyancy adjusting device 10 includes a buoyancy generating unit 11 and a control unit 12. The buoyancy generation unit 11 increases or decreases the apparent buoyancy by adjusting the balance between the gas G contained therein and the seawater W. The control unit 12 injects seawater W into the buoyancy generating unit 11 and drains the seawater W from the buoyancy generating unit 11.

The buoyancy generating portion 11 has a ballast tank 13 (tank portion) and a rubber bladder 14 (bag portion). The ballast tank 13 has a hollow and cylindrical shape. The ballast tank 13 is arranged in the pod 4 so that its axis is parallel to the axis of the pod 4. The pod 4 may be a pressure-resistant container in which seawater W does not enter. In this case, since the ballast tank 13 is not exposed to the seawater W, the size (volume) of the ballast tank 13 does not affect the buoyancy. On the other hand, the pod 4 may have a frame structure, for example, which is not a pressure-resistant container, and the ballast tank 13 may be attached to the frame structure. In this case, since the ballast tank 13 is exposed to the seawater W, the size (volume) of the ballast tank 13 affects the buoyancy.

The ballast tank 13 has a pair of disc-shaped end walls 16 and side walls 17 forming a cylindrical outer peripheral surface. The joint portion between the end wall 16 and the side wall 17 is airtightly connected. Therefore, the ballast tank 13 has an airtight structure. Therefore, the gas G filled inside the ballast tank 13 does not leak to the outside of the ballast tank 13. The gas G filled in the ballast tank 13 is, for example, air. The ballast tank 13 is made of a hard material such as metal. Therefore, the volume of the internal space S of the ballast tank 13 does not change. That is, the buoyancy (buoyancy in a narrow sense) generated by the ballast tank 13 alone is always constant. The ballast tank 13 has an opening 19 provided in the side wall 17. The opening 19 is provided at substantially the center of the ballast tank 13 in the axial direction.

The rubber bladder 14 is a hollow and flexible rubber bag body, and is arranged in the internal space S of the ballast tank 13. The rubber bladder 14 expands or contracts in the internal space S according to the volume of the seawater W to be filled. That is, the internal volume of the rubber bladder 14 roughly matches the volume of the seawater W filled in the rubber bladder 14. Further, the rubber bladder 14 shrinks in the internal space S until the initial shape is obtained by draining the seawater W. When the rubber bladder 14 is arranged inside the ballast tank 13, the internal space S of the ballast tank 13 becomes a gas chamber S1 filled with gas G and a liquid chamber S2 filled with seawater W inside the rubber bladder 14. Be separated. Since the rubber bladder 14 has flexibility, the volume ratio of the gas chamber S1 and the liquid chamber S2 in the internal space S is variable.

The rubber bladder 14 has a water supply / drainage unit 21. The water supply / drainage unit 21 supplies the seawater W to the inside of the rubber bladder 14 and drains the seawater W inside. The water supply / drainage unit 21 is provided substantially at the center of the axis of the ballast tank 13. Then, the water supply / drainage unit 21 is fixed to the side wall 17 of the ballast tank 13 and connected to the receiving port 12a of the control unit 12. Specifically, the water supply / drainage portion 21 is fixed to the outer peripheral side of the side wall 17. That is, it can be said that the opening 19 of the ballast tank 13 is closed by the rubber bladder 14. Therefore, no liquid or gas enters or exits the gas chamber S1 of the ballast tank 13 from the opening 19.

The control unit 12 has a valve 22 and a pump 23. The control unit 12 may have additional components as needed. The control unit 12 takes in the seawater W from the intake port 12b provided in the pod 4, and injects the seawater W into the rubber bladder 14 via the valve 22 and the pump 23. Further, the control unit 12 drains seawater W from the inside of the rubber bladder 14 to the outside of the pod 4 via the intake port 12b via the valve 22 and the pump 23.

For example, when seawater W is injected into the rubber bladder 14, when the air pressure in the gas chamber S1 is smaller than the water pressure at the floating position of the pod 4, the seawater W can be injected into the rubber bladder 14 simply by opening the valve 22. On the other hand, when the air pressure in the gas chamber S1 is larger than the water pressure in the floating position of the pod 4, seawater W can be injected into the rubber bladder 14 by opening the valve 22 and applying the water pressure by the pump 23.

Further, in the case of draining the seawater W from the rubber bladder 14, when the air pressure in the gas chamber S1 is larger than the water pressure at the floating position of the pod 4, the seawater W can be drained from the rubber bladder 14 simply by opening the valve 22. On the other hand, when the air pressure in the gas chamber S1 is smaller than the water pressure in the floating position of the pod 4, the seawater W can be drained from the rubber bladder 14 by opening the valve 22 and applying the water pressure by the pump 23.

That is, since the control unit 12 includes the valve 22, it controls the injection of seawater W into the rubber bladder 14 using water pressure and the drainage of seawater W from the rubber bladder 14 using the compressed gas in the gas chamber S1. Can be done.

Further, since the control unit 12 includes the pump 23, it is possible to control the injection and drainage of seawater W into the rubber bladder 14 without being influenced by the water pressure received by the buoyancy compensator 10 and the air pressure in the gas chamber S1. ..

The buoyancy control by the buoyancy compensator 10 will be described with reference to FIG. The buoyancy compensator 10 controls the apparent buoyancy F3 based on the buoyancy F2 in the narrow sense due to the volume of the ballast tank 13 and the gravity F1 due to the weight of the buoyancy compensator 10. More specifically, the apparent buoyancy F3 is the difference between the gravity F1 due to the weight of the buoyancy compensator 10 and the buoyancy F2 in the narrow sense. Here, the ballast tank 13 has a predetermined volume, and the volume does not change. On the other hand, the weight of the buoyancy compensator 10 can be increased or decreased depending on the amount of seawater W accepted by the rubber bladder 14. Therefore, the buoyancy compensator 10 can increase or decrease its weight by controlling the amount of seawater W received by the rubber bladder 14. Therefore, the buoyancy compensator 10 can control the apparent buoyancy F3.

For example, where the buoyancy F2 in the narrow sense of the buoyancy compensator 10 is constant, the weight of the buoyancy compensator 10 increases due to the acceptance of seawater W. Therefore, the apparent buoyancy F3 of the buoyancy compensator can be reduced (see part (a) of FIG. 3). On the other hand, the buoyancy compensator 10 can also drain the seawater W from the rubber bladder 14. Then, where the buoyancy F2 in the narrow sense is constant, the weight of the buoyancy compensator 10 is reduced by the drainage of seawater W. Therefore, the apparent buoyancy F3 of the buoyancy compensator 10 can be increased (see part (b) of FIG. 3).

According to this configuration, in the control of the apparent buoyancy F3, only the seawater W needs to be injected or drained into the buoyancy adjusting device 10, and the gas G is not consumed. Therefore, the buoyancy compensator 10 can continuously perform an operation of repeatedly increasing or decreasing the apparent buoyancy F3.

Further, the ballast tank 13 has a cylindrical shape having a pair of end walls 16 and a tubular side wall 17 connecting the pair of end walls 16. The side wall 17 has an opening 19 (opening). The rubber bladder 14 has a water supply / drainage portion 21 fixed to the side wall 17 and through which the opening 19 is inserted. According to this configuration, when the buoyancy compensator 10 is mounted on the pod 4, the ballast tank 13 can be mounted so that the axial direction of the ballast tank 13 faces the horizontal direction. Then, it is possible to increase the volume occupied by the buoyancy compensator 10 in the space formed by the casing of the pod 4. Therefore, the amount of control of the apparent buoyancy F3 that can be controlled by the buoyancy compensator 10 can be expanded.

<Second Embodiment>
By the way, the orientation of the pod 4 is usually horizontal (see FIG. 1). However, the orientation of the pod 4 may be upward (see part (a) in FIG. 4) or downward with respect to the horizontal. Part (a) of FIG. 4 shows the power generation device 2 according to the first embodiment. When the pod 4 is tilted upward with the seawater W in the rubber bladder 14, the surface of the seawater W in the rubber bladder 14 tries to keep the level, so that the seawater W is biased. That is, the seawater W is offset below the ballast tank 13. Then, the rubber bladder 14 is also deformed diagonally downward due to the deviation. The rubber bladder 14 is fixed to the ballast tank 13 in the water supply / drainage section 21. Then, according to this deformation, a tensile force is generated between the opening 19 of the ballast tank 13 and the water supply / drainage portion 21, and a load may act on the rubber bladder 14. The load on the rubber bladder 14 is due to the inclination of the pod 4. Therefore, in the long-term operation of the power generation system 1, the rubber bladder 14 may be repeatedly loaded.

Therefore, as shown in part (b) of FIG. 4, the buoyancy compensator 10A according to the second embodiment included in the power generation device 2A has a pair of connecting ropes 26 (first connecting part, second connecting part). .. The connecting rope 26 suppresses the generation of a load in the water supply / drainage portion 21 of the rubber bladder 14. One connecting rope 26 connects one end wall 16 and the outer peripheral surface 14a of the rubber bladder 14 facing the end wall 16. Similarly, the other connecting rope 26 connects the other end wall 16 and the outer peripheral surface 14b of the rubber bladder 14 facing the end wall 16. The length of these connecting ropes 26 is shorter than the length from the end wall 16 to the water supply / drainage portion 21.

According to the connecting rope 26, even if the rubber bladder 14 tries to deform diagonally downward, the connecting rope 26 inhibits the deformation. Therefore, the generation of a load in the water supply / drainage portion 21 of the rubber bladder 14 is suppressed.

Therefore, the connecting rope 26 arranged in the front suppresses the deviation of the rubber bladder 14 that may occur when the pod 4 is tilted upward. On the other hand, the connecting rope 26 arranged rearward suppresses the deviation of the rubber bladder 14 that may occur when the pod 4 is tilted downward.

In short, the ballast tank 13 has a connecting rope 26 that connects one end wall 16 and the rubber bladder 14, and a connecting rope 26 that connects the other end wall 16 and the rubber bladder 14. According to this configuration, when the buoyancy compensator 10A is tilted obliquely, it is possible to prevent the rubber bladder 14 from being biased downward due to the weight of the seawater W contained therein. Then, it is possible to suppress the load from acting on the water supply / drainage portion 21 of the rubber bladder 14 fixed to the side wall 17.

Further, the length of the connecting rope 26 is shorter than the length from the end wall 16 to the water supply / drainage portion 21. According to this configuration, the end portion of the rubber bladder 14 to which the connecting rope 26 is connected does not move to the other end wall 16 from the water supply / drainage portion 21. Therefore, it is possible to reliably suppress the load from acting on the water supply / drainage unit 21.

Although the embodiment of the present invention has been described, the present invention is not limited to the above embodiment.

For example, in the above embodiment, a cylindrical ballast tank and a barrel-shaped rubber bladder have been exemplified. The shapes of the ballast tank and rubber bladder are not limited to these. For example, the buoyancy compensator may use a spherical ballast tank and a spherical rubber bladder.

Further, the buoyancy compensator may have a plurality of water supply / drainage units.

Further, the buoyancy compensator 10 is not limited to the power generation system, and may be applied to various underwater devices. The buoyancy compensator 10 can be applied to an underwater device that floats in water for a long period of time and requires buoyancy adjustment.

Further, a buoyancy adjusting system having a plurality of buoyancy adjusting devices 10 may be mounted on one pod 4. In this case, the control unit 12 in each buoyancy compensator 10 is controlled by a control signal provided by the integrated control unit. According to the plurality of buoyancy compensators 10, it is possible to control the attitude of the pod 4 in addition to the ascent and sinking of the pod 4.

1 Power generation system 2, 2A Power generation device 3 Mooring structure 3a Mooring line 3b Transmission cable 4 Pod 6 Cross beam 7 Turbine 8 Blade 9 Anchor 10, 10A Buoyancy adjustment device 11 Buoyancy generator 12 Control unit 12a Inlet 12b Intake 13 Ballast tank 14 Rubber bladder 14a Outer surface 14b Outer surface 16 End wall 17 Side wall 19 Opening 21 Water supply / drainage 22 Valve 23 Pump 26 Connecting rope F1 Gravity F2 Buoyancy in a narrow sense F3 Apparent buoyancy FL Sea flow G Gas S Internal space S1 Gas room S2 Liquid room WB Sea bottom W seawater

Claims (5)

A tank portion that forms an internal space having a predetermined volume and includes a gas chamber filled with gas in the internal space, and a tank portion.
A bag portion housed in the internal space and forming a liquid chamber separated from the gas chamber in the internal space.
A control unit for controlling the injection of liquid into the liquid chamber and the drainage of the liquid from the liquid chamber is provided .
The tank portion has a cylindrical shape having a pair of end walls and a tubular side wall connecting the pair of end walls, and a first connecting portion connecting the one end wall and the bag portion. And a second connecting portion that connects the other end wall and the bag portion.
The side wall has an opening
The bag portion is a buoyancy compensator having a water supply / drainage portion fixed to the side wall and inserted through the opening. The buoyancy compensator according to claim 1 , wherein the length of the first connecting portion is shorter than the length from one of the end walls to the water supply / drainage portion. The buoyancy compensator according to claim 1 or 2 , wherein the control unit includes a valve. The buoyancy compensator according to any one of claims 1 to 3 , wherein the control unit includes a pump. The buoyancy compensator according to any one of claims 1 to 4 and
An integrated control unit that provides a control signal to the control unit, and a buoyancy adjustment system provided.

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