JP6907775B2 - Underwater floating device - Google Patents

Description

The present invention relates to an underwater floating device.

Conventionally, an underwater floating type device has been known in which a device is settled from the water into water, performs an operation according to a desired purpose, and then floats on the water again. In such a device, it is known that a ballast tank is provided inside and the depth of the device is adjusted by pouring and draining water into the ballast tank (see, for example, Patent Document 1).

International Publication No. 2014/163141

In a submersible floating device, water injection and drainage to the ballast tank is generally performed using a pump. Here, if the device is configured to repeatedly inject and drain water by the pump so that the device can stay at a desired depth (water depth) in order to perform the desired operation, the power consumption related to the driving of the pump increases. there is a possibility.

The present invention has been made in view of the above, and an object of the present invention is to provide an underwater floating device capable of controlling the floating depth while suppressing power consumption.

In order to achieve the above object, the underwater floating device according to the present invention is an underwater floating device moored by a mooring rope and floats in a water stream, and includes a ballast tank for adjusting the weight of the own device and the above. A water injection / drainage unit that changes the amount of water in the ballast tank, a flow velocity measurement unit that measures the flow velocity of the water flow, and an amount of water in the ballast tank for suspending the own device to a desired depth for each predetermined flow velocity range. It has a control unit that holds water amount setting information associated with the set value of the above and controls the amount of water in the ballast tank by the water injection / drainage unit based on the flow velocity measured by the flow velocity measuring unit.

According to the above-mentioned underwater floating device, the amount of water in the ballast tank is adjusted based on the water amount setting information held by the control unit and the flow velocity measured by the flow velocity measuring unit, and the weight of the underwater floating device is adjusted. can do. In the underwater floating device, the thrust force applied to the device and the tension due to the mooring line change according to the influence of the water flow, and the force applied in the vertical direction of the device changes. On the other hand, like the underwater floating device, by controlling the amount of water in the ballast tank 20 for each flow velocity and adjusting the weight, the underwater floating device 1 can appropriately float near a desired depth. Can be controlled. Further, since the amount of water in the ballast tank 20 is set according to the flow velocity of the water flow for each predetermined range, the power consumption can be reduced and the change in depth due to overshoot can be reduced. , It becomes possible to perform depth control while suppressing power consumption.

Here, the water amount setting information can be an aspect that stipulates that the set value of the water amount in the ballast tank is reduced according to the increase in the flow velocity of the water flow.

As described above, the amount of water in the ballast tank is reduced according to the increase in the flow velocity of the water flow, so that the underwater floating device can be continuously suspended within a desired depth range.

Further, it may further have a power generation unit that generates power by using the water flow, and the water injection / drainage unit may operate by using the electric power generated by the power generation unit.

As described above, when the water injection / drainage unit operates using the electric power generated by the power generation unit, power is generated by not controlling the amount of water finely in response to a slight change in the flow velocity. It is possible to reduce the use of electricity. Therefore, it is possible to increase the substantial amount of power generated in the power generation unit of the underwater floating device.

According to the present invention, there is provided an underwater floating device capable of controlling the floating depth while suppressing power consumption.

It is a figure which shows the whole structure which concerns on the underwater floating type apparatus which concerns on embodiment of this invention. It is a figure explaining the functional structure of the underwater floating type apparatus. It is a figure which showed the information (water amount setting information) which shows the relationship between the flow velocity and the set value of the water amount in a tank. It is a block diagram which shows an example of a pouring drainage part. It is a figure explaining the method of controlling the amount of water of a tank in an underwater floating apparatus.

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.

In the following description, the terms "upstream" or "downstream" are used with reference to water flow. 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.

The underwater floating device 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, the underwater floating device 1 includes a main body 10 (pod) and a propeller 11, and is a device that is moored and floats at a fixed point in water such as in the sea via a mooring line 2. be. One end of the mooring line 2 is fixed to the sinker 3 fixed to the seabed, and the other end is connected to the underwater floating device 1. The underwater floating device 1 is a device that floats in water and performs some operation. For example, a floating power generation device (underwater floating sea current power generation device) that generates power by using a water flow such as an ocean current, information in water. It is realized as a device for collecting electricity.

In the present embodiment, the case where the underwater floating device 1 is a so-called downwind type underwater floating power generation device will be described, but the present invention is not limited thereto. When the underwater floating device 1 is an underwater floating power generator, the underwater floating device 1 has a function of converting the rotation of the propeller 11 generated by the water flow FL into electricity by the generator while floating in the water flow FL. .. The rotation of the propeller 11 generates a thrust in a substantially horizontal direction, that is, a thrust force F1.

Further, the underwater floating device 1 has a ballast tank 20 for accommodating water such as seawater in the main body 10. By changing the amount of water in the ballast tank 20, the weight of the underwater floating device 1 can be changed, and the force F2 for floating the underwater floating device 1 can be adjusted. Thrust force F1 due to the water flow FL, buoyancy, gravity, and rope tension from the mooring rope 2 act on the underwater floating device 1. At the position where these are balanced, the underwater floating device 1 is in a state of being suspended in water. When the underwater floating device 1 is suspended at a predetermined depth (water depth) in water, the force F2 for levitating the device, which is obtained from the vertical components of buoyancy, gravity, and cord tension, becomes zero. When the vertical force changes from zero, the underwater floating device 1 moves in the vertical direction according to the force. The underwater floating device 1 according to the present embodiment has a function of adjusting the depth (water depth) at which the device floats by changing the amount of water in the ballast tank 20 based on the flow velocity of the surrounding water flow FL.

As shown in FIG. 2, the underwater floating device 1 includes a propeller 11 attached to a rotating shaft, a power generation unit 12 that converts the rotation of the rotating shaft due to the rotation of the propeller 11 into electricity, a flow velocity sensor 13, and a control unit. It has 15. Further, it has a water injection / drainage unit 21 for adjusting the amount of water in the ballast tank 20 and a level sensor 22.

The power generation unit 12 is configured to include a generator, and has a function of receiving the rotation of the propeller 11 by the water flow FL via the rotation shaft and converting the rotation into electricity.

The flow velocity sensor 13 has a function of measuring the flow velocity of the water flow around the underwater floating device 1. As the flow velocity sensor 13, for example, an electromagnetic current meter or the like can be used. The information related to the flow velocity of the water flow measured by the flow velocity sensor 13 is used for controlling the amount of water in the ballast tank 20 of the underwater floating device 1 by the control unit 15. The timing of the flow velocity measurement by the flow velocity sensor 13 is not particularly limited, but may be configured to measure at predetermined intervals (for example, every few seconds). Further, the configuration may be such that the monitoring is constantly performed, but the configuration may be such that the measurement is performed at the timing specified by the control unit 15.

The control unit 15 has a function of controlling the amount of water in the ballast tank 20 by utilizing a part of the electricity generated by the power generation unit 12. The control unit 15 is, for example, a computer composed of hardware such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and software such as a program stored in the ROM. It can be realized.

If the underwater floating device 1 is not a floating power generation device, a power supply device or the like for controlling the amount of water in the ballast tank 20 by the control unit 15 and the control unit 15 may be separately provided. Further, when the underwater floating device 1 can communicate with the external device, the control unit 15 that receives the signal from the external device has a function of executing the process related to the control of the amount of water in the ballast tank 20. May be good.

The control unit 15 controls the amount of water in the ballast tank 20 based on the flow velocity of the water flow measured by the flow velocity sensor 13. Specifically, the control unit 15 holds information (water amount setting information) indicating the relationship between the flow velocity shown in FIG. 3 and the set value of the water amount in the tank. In the underwater floating device 1 according to the present embodiment, as shown in FIG. 3, the flow velocity is divided into predetermined ranges (numerical ranges), and the set values of the amount of water in the ballast tank 20 are associated with each range. .. This set value indicates the amount of water held in the ballast tank 20 so that the underwater floating device 1 floats near a desired water depth (depth). Therefore, when the depth at which the underwater floating device 1 is suspended is changed, the numerical values (set values) and the like included in this information are changed. When the underwater floating device 1 tries to continue floating near a desired water depth (depth), the rotation speed of the propeller 11 increases as the flow velocity of the water flow increases, so that the thrust force applied to the device increases. Therefore, it is necessary to increase the upward force F2 applied to the device by reducing the amount of water in the ballast tank 20. FIG. 3 illustrates the above relationship, and stipulates that the set value of the amount of water in the ballast tank is reduced as the flow velocity of the water flow increases. How to divide the numerical range is not particularly limited, but for example, the interval (width of the flow velocity) for dividing the numerical range is 0.7 m / s to 1 m / s (flow velocity is 0.7 m / s to 1 m). The set value of the amount of water is changed every time / s changes). The method of dividing the numerical range (width of the flow velocity) that determines the set value is based on the environment of the water area (sea area) where the underwater floating device 1 is suspended, how much the underwater floating device 1 is allowed to move in the depth direction, and the like. Is set as appropriate. Further, the method of dividing the numerical range (width of the flow velocity) that determines the set value does not have to be uniform, and may be different for each range of the flow velocity. Further, the set value for each range of the flow velocity can be calculated in advance by using, for example, a simulation or the like.

The control unit 15 compares the measurement result of the flow velocity sensor 13 with the water amount setting information shown in FIG. 3, determines whether or not to change the water amount of the ballast tank 20, and changes the water amount as necessary. The water amount setting information indicating the relationship between the flow velocity and the set value of the water amount in the tank as shown in FIG. 3 is created in advance before operating the submersible floating device 1 and stored in the control unit 15.

The ballast tank 20 is provided in the main body 10. The ballast tank 20 is provided with a water injection / drainage unit 21 for injecting / draining water and a level sensor 22 for measuring the amount of water inside.

An example of the injection / drainage unit 21 is shown in FIG. The water injection / drainage unit 21 includes a pump P, a first line L1, a second line L2, a connection line L3, and on-off valves M1 to M4. On the first line L1, on-off valves M1 and M2 are provided, and a connecting port with the connecting line L3 is provided between the on-off valves M1 and M2. Similarly, on the second line L2, on-off valves M3 and M4 are provided, and a connecting port of the connecting line L3 is provided between the on-off valves M3 and M4. The pump P is provided on the connection line L3, and by driving the pump P, it is possible to send liquid in the direction from the first line L1 side to the second line L2 side.

In the water injection / drainage section 21, when the on-off valves M2 and M3 are opened, the on-off valves M1 and M4 are closed and the pump is driven, a water channel passing through the on-off valves M2, the pump P and the on-off valve M3 is opened. It is formed and water can be supplied into the ballast tank 20 from the outside. Further, in the water injection / drainage section 21, when the on-off valves M1 and M4 are opened, the on-off valves M2 and M3 are closed, and the pump is driven, the water channel passing through the on-off valves M1, the pump P and the on-off valve M4. Is formed, and the water in the ballast tank 20 can be discharged to the outside. As described above, the water injection / drainage unit 21 shown in FIG. 5 can perform water injection / drainage of the ballast tank 20 by controlling the opening / closing of the on-off valves M1 to M4 and driving one pump P.

Further, the water injection / drainage by the water injection / drainage unit 21 is carried out while monitoring the amount of water in the ballast tank 20 by the level sensor 22. The level sensor 22 is a sensor that detects the water level in order to measure the amount of water in the ballast tank 20. The method of detecting the water level by the level sensor 22 and the installation position of the sensor are not particularly limited as long as the amount of water in the ballast tank 20 can be appropriately measured. Further, the ballast tank 20 may be configured to measure the amount of water by a means different from that of the level sensor 22.

Next, a control method for controlling the depth of the underwater floating device 1 will be described with reference to FIG.

First, as a premise, in the underwater floating device 1, the target depth is set in advance in the control unit 15. Then, water amount setting information showing the relationship between the flow velocity for maintaining the target depth and the set value of the water amount in the tank is prepared. The target depth may be set before the underwater floating device 1 is put into water, or may be set based on an instruction from an external device or the like after being put into water.

Next, according to the instruction of the control unit 15, the flow velocity of the water flow is measured by the flow velocity sensor 13 (S1). Then, the amount of water in the ballast tank 20 is determined based on the water flow measured by the flow velocity sensor based on the water amount setting information held by the control unit 15, and the ballast tank is determined by using the water injection / drainage unit 21 and the level sensor 22. The amount of water in 20 is controlled (S2).

After that, based on the instruction of the control unit 15, the flow velocity sensor 13 continues to measure the flow velocity (S3). Then, the control unit 15 determines whether it is necessary to change the amount of water in the ballast tank 20 based on the water flow measured by the flow velocity sensor 13 (S4). The state in which the amount of water in the ballast tank 20 needs to be changed is a state in which the set value of the amount of water in the ballast tank 20 (see FIG. 3) set by dividing the flow velocity into predetermined ranges changes, and each range. It is a state in which the flow velocity has changed beyond the division of. In this way, when the control unit 15 determines that the amount of water in the ballast tank 20 should be changed based on the change in the flow velocity (S4-YES), the control unit 15 returns to the set value corresponding to the measured flow velocity. Change the amount of water in (S5). On the other hand, when the control unit 15 determines that the change in the amount of water in the ballast tank 20 is unnecessary (S4-NO) because the flow velocity does not change or is slight, the control unit 15 determines that the amount of water in the ballast tank 20 does not need to be changed. For example, a state in which no particular instruction is given to the water injection / drainage unit 21 is set so as to maintain the above (S6).

After that, it is determined whether or not to end the management of the amount of water in the tank (S7), and a series of processes (S3 to S7) are repeated until the end.

As described above, according to the submersible floating device 1 according to the above embodiment, the water amount setting information related to the set value of the water amount in the ballast tank 20 set for each flow velocity of the water flow in the predetermined numerical range in the control unit 15. To hold. Then, the amount of water in the ballast tank 20 can be adjusted based on the water amount setting information and the flow velocity measured by the flow velocity sensor 13 which is a flow velocity measuring unit, and the weight of the underwater floating device 1 can be adjusted. In the underwater floating device 1, the thrust force F1 changes according to the influence of the water flow in the area where the device is installed, and the direction and magnitude of the rope tension due to the mooring rope change accordingly. As a result, the vertical force applied to the underwater floating device 1 changes, and as a result, the force F2 that raises the underwater floating device 1 also changes. Therefore, like the underwater floating device 1 of the present embodiment, the underwater floating device 1 is desired by controlling the amount of water in the ballast tank 20 for each flow velocity and adjusting the floating force F2 applied to the device. It can be appropriately controlled so that it can float near the depth.

Further, in the underwater floating device 1 according to the above embodiment, the amount of water in the ballast tank 20 is set for each flow velocity of the water flow in a predetermined range. As a result, it is possible to adjust the depth while suppressing the power consumption of the underwater floating device 1.

Theoretically, in order to suspend the underwater floating device 1 to a desired depth, it is necessary to finely adjust the weight of the underwater floating device 1 according to the flow velocity. Therefore, it is required to finely change the amount of water in the ballast tank 20 for adjusting the weight. However, in order to adjust the amount of water in the ballast tank 20, it is necessary to operate the water injection / drainage unit 21 including the pump P, so that the power consumption increases by repeating the fine adjustment. Further, when the amount of water in the ballast tank 20 is changed, the overshoot tends to be large due to the change in the depth of the underwater floating device 1. Therefore, it was found that it is difficult for the underwater floating device 1 to stay at a desired depth even when the amount of water in the ballast tank 20 is finely adjusted repeatedly.

On the other hand, in the underwater floating device 1 according to the present embodiment, the amount of water in the ballast tank 20 is set in correspondence with the flow velocity of the water flow for each predetermined range. In this way, while the flow velocity of the water flow is within a predetermined range, the amount of water in the ballast tank 20 is not changed, and the amount of water is not finely controlled in response to a slight change in the flow velocity, thereby reducing power consumption first. can do. Further, since the amount of water in the ballast tank 20 may not be changed even when the flow velocity of the water flow changes, it is expected that the depth of the underwater floating device 1 will change slightly, but the change in depth due to overshoot may occur. As a result, the underwater floating device 1 can be suspended within a desired depth range. As described above, according to the underwater floating device 1 according to the present embodiment, it is possible to perform depth control while suppressing power consumption.

Further, the underwater floating device 1 according to the above embodiment is configured to reduce the amount of water in the ballast tank 20 in accordance with an increase in the flow velocity of the water flow. With such a configuration, it is possible to continuously float the underwater floating device 1 within a range of a desired depth.

Further, when the submersible floating device 1 according to the above embodiment has a power generation unit 12 and the water injection / drainage unit 21 operates by using the electric power generated by the power generation unit 12, the above-mentioned As described above, the use of generated electric power can be reduced by configuring the configuration so that the amount of water is not finely controlled in response to a slight change in the flow velocity. Therefore, it is possible to increase the substantial amount of power generated by the power generation unit 12.

Although the underwater floating device 1 according to the embodiment of the present invention has been described above, the present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the gist thereof. ..

For example, in the above embodiment, the example in which one underwater floating device 1 is connected to the mooring line 2 has been described, but two underwater floating devices 1 each having a propeller 11 are connected to each other. It may be configured as such. In this case, each of the two underwater floating devices 1 can be moored to the same fixed point in the water by a mooring line. Further, by setting the rotation directions of the propellers 11 of the two underwater floating devices 1 to be different from each other, the postures of the two underwater floating devices 1 can be stabilized.

Further, in the above embodiment, the configuration in which the ballast tank 20 is provided in the main body 10 has been described, but in addition to the main body 10, a pod or the like for adjusting the weight of the entire device is separately provided. The ballast tank 20 may be provided on the pod.

Further, the fixing point for fixing the mooring line connected to the underwater floating device 1 does not have to be below the underwater floating device 1, and its height (depth) position can be changed.

Further, in addition to the underwater floating device 1 described in the above embodiment, a device for measuring the depth of the own device is provided, and the control unit 15 controls the amount of water in the ballast tank 20 by combining the depth measurement results. May be good. For example, if the amount of water in the ballast tank 20 is controlled so as to be the set value indicated in the water amount setting information, but the actual floating depth is different from the desired depth, the control unit 15 In the above, the setting value in the ballast tank 20 in the water amount setting information may be changed (corrected).

1 Submersible floating device 10 Main body 11 Propeller 12 Power generation unit 13 Flow velocity sensor 15 Control unit 20 Ballast tank 21 Water injection / drainage unit 22 Level sensor

Claims (3)

An underwater floating device that is moored by a mooring line and floats in a stream of water.
A ballast tank for adjusting the weight of your device,
An injection / drainage unit that changes the amount of water in the ballast tank,
A flow velocity measuring unit that measures the flow velocity of the water flow,
For each range of a predetermined flow velocity, water amount setting information associated with a set value of the amount of water in the ballast tank for suspending the own device at a desired depth is held, and the water amount setting information and the flow velocity measuring unit are used. based on the measured flow rate, and a control unit for controlling the amount of water in the ballast tank by the Note drainage unit,
Underwater floating device with. The submersible floating device according to claim 1, wherein the water amount setting information is information that stipulates that the set value of the water amount in the ballast tank is reduced in accordance with an increase in the flow velocity of the water flow. It also has a power generation unit that uses the water flow to generate electricity.
The underwater floating device according to claim 1 or 2, wherein the water injection / drainage unit operates by utilizing the electric power generated by the power generation unit.

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