JP2022123981A - Buoyancy body that generates and supplies power in water - Google Patents

Abstract

To enable power generation and power supply to outside by repeated sinking and surfacing of a buoyancy body that includes a water turbine and has controllable buoyancy.SOLUTION: A buoyancy body 10, having controllable buoyancy, includes a cabinet 11 with a balloon 17 to change its volume by a working fluid, causing the buoyancy body 10 to sink or surface. A stream of water generated relative to the cabinet 11 rotates a turbine rotor 13 and a turbine blade 12 equipped in the cabinet to generate power. Its power is accumulated in a storage battery 51 inside the cabinet. Power supply means 52 equipped in the cabinet supplies power to outside.SELECTED DRAWING: Figure 1

Description

The present invention relates to a controllable buoyant body equipped with a rim-type hydro-turbine power generation system and a power supply system.

Some prior art UUVs have traveled at speeds of less than 2 knots per hour in water depths of about 2000 meters or less. UUVs, which move at a low speed below about 2,000 meters, lack power energy in deep-sea environments.

The density of sea water is 832 times that of air, which means that a 5 knot flow has more kinetic energy than a 350 km/h wind. A scheme of placing underwater turbines in coastal areas with strong currents is known, such as a scheme being implemented in Lake Strangford in Northern Ireland by Marine Current Turbines Ltd. of Bristol, UK. Here, 15-20 meter wide turbine blades are rotated at 10-20 revolutions per minute by tidal current action. A prototype is in operation in Strangford Sound, Northern Ireland, using twin rotors 16 meters in diameter and generating a rated power of 1.2 MW at a current velocity of 2.4 m/s. In this case, the overall efficiency of the turbine system to convert the kinetic energy of water into electricity is 43%.

Deployment of such a project, however, is dependent on local coastal conditions to produce adequate tidal currents, and is unsuitable, for example, in offshore deep waters. Thus, a subsea solution for generating electricity using hydro-driven turbines that 1) can be deployed underwater without strong natural currents and 2) has a high power output per cubic meter of ocean space utilized. is needed.

And because to refuel, the UUV must frequently surface to put it at potential risk of collision or course interruption with surface ships, so a subsea solution is needed that can refuel power energy without surfacing. It is

JP 2018-112191 A WO 2009/026610 pamphlet British Patent No. 2456798 U.S. Patent No. 2006/017292 British Patent No. 507093 U.S. Patent No. 2005188691

One aspect of the present invention addresses the above problems by providing a variable buoyancy body with a hydraulic turbine for storing and generating electricity. The buoyant body is operable in a body of water having depth so that it can move from water to the surface by buoyancy and downward by gravity. The buoyant body is negatively buoyant to facilitate its sinking, but is further equipped with adjustable buoyancy means so that the buoyant body can be given positive buoyancy if desired. When positive buoyancy is applied, the buoyant body will float upward due to the buoyant force. When negative buoyancy is applied, it sinks downward due to gravity. As it moves, the relative motion of the buoyant body and the water creates an effective artificial flow to turn the turbine rotor, and permanent magnets at the ends of the turbine blades generate electricity through excitation coils in the shroud or housing.

In order to provide controllable buoyancy, in some embodiments, a pressure accumulator is provided on the buoyant body and supplies a working fluid having a specific gravity of less than 1.0, such as oil or gas, at a suitable pressure when a set depth is reached. Equipped. The buoyant body is equipped with similar buoyancy control means such as a balloon that can store a working fluid with a specific gravity less than 1.0, such as oil or gas, to give the buoyant body an overall positive buoyancy.
It is also equipped with a pump capable of transferring working fluid from similar buoyancy control means, such as a balloon, to the accumulator to provide a generally negative buoyancy to the buoyant body.

The energy required by the accumulator to pressurize the working fluid enough to give positive buoyancy and the energy required to pump enough working fluid, such as oil or gas, to give negative buoyancy, is greater than the energy generated in the buoyant body. The energy required to run the pump is important because it is small and therefore the device is supposed to be energy positive in terms of power generation.

In one typical configuration, the diameter of the turbine blades may be in the range of 0.5 meters to 15 meters, and the weight of the buoyant body and associated generator equipment and balloon is approximately 0.1 tons to 15 meters. tons. It is envisioned that the descent and ascent distances range from 100 to 1000 meters. For example, a 10 ton turbine on water 2000 meters deep has a potential energy of 196 MJ. If this were to sink at 2.4 m/sec, a potential power of up to 471 kW would be available, assuming 100% efficiency. Such efficiency is not possible, but even a conservative estimate of efficiency of only 30% would produce a power output of over 140 kW. With the same efficiency (43%) as the prior art turbine, over 200 kW of power is generated in 832 seconds (the time required for the buoyant body to descend 2000 meters).

Water pressure at 2000 m is about 2900 psi (20 MPa), but accumulators such as those available from Nippon Accumulator Co. produce discharge pressures of about 3000 psi (21 MPa), e.g. The vessel can deliver 1100 liters per minute of working fluid with a specific gravity less than 1.0 (specifically see model number HN-N21MP-L29-AAA for illustration). To lift 5 tons of mass from the sea bed would require displacing more than 10 m3 of water to create positive buoyancy, but with such an accumulator this working fluid capacity can be expanded at an appropriate pressure to Positive buoyancy can be supplied in less time than the time required for the buoyant body to sink. The system is energy positive because the buoyant body generates electricity even on the way up.

The discharge pressure of the accumulator is about 2900 psi (20 MPa), but high pressure pumps such as those available from Nachi-Fujikoshi produce a discharge pressure of 4500 psi (30 MPa), e.g. 111 cubic meters per hour of working fluid can be stored in the accumulator from the pump output of (specifically, for illustration, see model number IPH-4B-32-20). With such a pump, this volume of working fluid can be supplied with negative buoyancy at a suitable pressure in a time less than the time required for the buoyant body to surface. The system is energy positive because the buoyant body generates electricity even during its descent, and although some of the electricity generated is required to operate the pump, this is generated by the turbine during its ascent and descent. much less than the amount of power

In view of the above, according to one aspect, the present invention provides a buoyant body comprising a series of rotatable turbine rotors communicatively coupled to a power generation system arranged to generate electricity in association with rotation of turbine blades. wherein said buoyant body is further equipped with a buoyancy control system arranged to controllably impart positive and negative buoyancy to said buoyant body, said buoyant body further comprising: said buoyant body is for submersion in water and said buoyant body is arranged to accompany movement of the buoyant body in water.

FIG. 1 is a schematic side view showing a buoyant body in one embodiment of the invention. 2 is a schematic plan view showing the buoyant body of FIG. 1. FIG. FIG. 3 illustrates a typical deployment scenario in one embodiment of the invention. FIG. 4 is a flow diagram illustrating the method of operation of one embodiment of the present invention. Figure 5 is a schematic side view of a buoyant body according to another embodiment of the invention; FIG. 6 is a schematic side view showing the rotor pitch adjustment mechanism. FIG. 7 is a flow chart for balloon control.

Further features and advantages of the invention will become more apparent from a further description of its embodiments, given by way of example only, and with reference to the accompanying drawings. Like reference numerals refer to like parts throughout the figures.

Figures 1 and 2 show an example of a buoyant body forming an embodiment of the present invention. The buoyant body 10 is equipped with a turbine rotor 13 equipped with turbine blades 12 bearing a casing 11 containing a generator, a storage battery, a pressure accumulator and a pump.

In one embodiment, the housing 14 may include permanent magnets 17 at the ends of the turbine blades 12 that support the shroud 14 with the excitation coils 16 therein and support the excitation coils 16 at the ends of the turbine blades 12 . The turbine blades 12 may be arranged to rotate about the housing 11 along with the turbine rotor 13 as the buoyant body 10 moves vertically in the water.

The buoyant body 10 equips the housing 11 with a shell 16, which in this embodiment is pressurized with an accumulator or pump when it is desired to provide positive buoyancy to the buoyant body 10. It includes a balloon 17 arranged to receive oil or air or other gas. In one embodiment, balloon 17 is an expandable lifting bag such as may be used in salvage operations. Preferably, however, the balloon has: A working fluid supply valve and a discharge valve are provided.

Further, the turbine rotor 13 and equipped turbine blades 12 are equipped with shrouds 14 each attached by a frame 15 to the central buoyant body and provided with excitation coils 16 . It is curved to act as a venturi for guiding at speeds faster than the speed of travel of the turbine blades 12 . This increases the water flow velocity through the turbine and the power harvested can be increased.

The buoyancy is weighted such that it is slightly negatively buoyant with respect to the sea surface when the balloon 17 is pumped of working fluid and deflated so that the shell 16 is filled with sea water. This means that the buoyant body can create positive buoyancy in the buoyant body with a minimum amount of working fluid when the buoyancy of the buoyant body is increased at a set depth or set condition, thereby maximizing energy efficiency. Guarantee.

In one embodiment, buoyant body 10 is used as an energy storage unit. Electrical energy is stored as potential energy in either positively or negatively buoyant or buoyant bodies that are mechanically held in water. While the potential energy is held, no energy is input to the buoyant body's turbine, nor is it output. However, when the buoyant body is released from the holding position, its buoyant force produces either an upward or downward force to generate electrical energy.

An upward force is generated when the buoyant body 10 is positively buoyant. The buoyant body may be held at its lowest point (ie, seabed or set depth) and the balloon may be filled with working fluid to make the buoyant body positively buoyant. The upward force produced by positive buoyancy produces upward movement of the buoyant body through the surrounding water, and the action of the turbine blades 12 traveling through the surrounding water causes the buoyant body to exert a rotational force on the turbine rotor 13. provided. The buoyant body provides electrical energy output until the upper limit of travel is reached. At this upper limit, the buoyant body remains positively buoyant in the water, so there is no motion and no electricity generated by the buoyant body in the water.

In this position, the buoyant body 10 stores gravitational potential energy that is pumped out of a balloon filled with working fluid to deflate the balloon and fill the space between the shell with water. Electrical energy can be released to generate electrical energy by filling to make the buoyant body negatively buoyant. The negatively buoyant buoyant body sinks through the surrounding water, and the turbine blades 12 provide rotational motion to the turbine rotor 13 to convert the relative water flow generated by the advancing casing into electrical energy. do. The buoyant body 10 continues to generate power while descending through the surrounding water, and stops generating power when it reaches the lower operating area.

FIG. 3 shows five operating configurations of buoyant bodies 10A-10F, each at a different stage of its lifting duty cycle. For example, buoyant body 10A is at upper water depth via the lower leg of its duty cycle. Therefore, electricity is generated as it moves underwater due to the effect of gravity. Similarly, buoyant body 10C is also in the descending phase of its duty cycle, but is at rest at the set depth or bottom.

Buoyant body 10C and buoyant body 10D are both in the rising phase of their respective duty cycles, but buoyant body 10D leads in time buoyant body 10C. Note that in this example, both buoyant bodies 10C and 10D are inflating balloons 18 provided within outer shell 16 to have positive buoyancy. In other embodiments, balloons with pressure regulating valves may be used. In still other embodiments, a combination of shell and balloon may be used. Depending on the positive buoyancy provided by the balloon and/or shell, the buoyant body 10E moves or floats in the water at a given speed, thus producing electricity as the turbine blades and turbine rotor rotate due to this action. Generate. In certain embodiments, the rate of ascent of the buoyant body is approximately matched to the rate of settling, thus achieving easy management of the individual duty cycles of the different buoyant bodies. However, this is not essential, so it is possible that the duration of the rising phase is different from the falling phase, eg longer than the falling phase.

The buoyant body 10C has completed its descent phase and is stationary. Within housing 14, a pressure accumulator and pump are provided to provide working fluid to balloon 17C. As shown, balloon 17D of buoyant body 10D is only partially filled with working fluid and is in the process of being filled by the accumulator and pump. When the balloon 17E of the buoyant body 10E is filled with the working fluid from the pressure accumulator to a sufficient amount to obtain positive buoyancy, the buoyant body 10E can float to the surface of the sea. is generated.

The buoyant body 10F has completed its ascent phase and is stationary. As shown, the balloon 17F of the buoyant body 10F is only partially filled with the working fluid, and the working fluid is transferred from the balloon 17F by the pump to the pressure accumulator and the balloon 17F deflates. in the process. When the balloon is deflated to an amount that provides sufficient negative buoyancy for sinking, the buoyant body 10F can sink into the water as the buoyant body 10A, generating electricity as it descends.

The buoyancy body duty cycle is shown in the flow diagram of FIG. First, the buoyant body is assumed to be at the top of the ascent stage. The valve is now opened to create a fluid circuit between the balloon and the pump to the accumulator so that all the working fluid is pumped out of the balloon and the balloon is deflated so that the buoyant body sinks under the force of gravity. (f.4.1). During sinking, the turbine blades rotate with the turbine rotor, which receives and connects the relative water flow, and electricity is generated (f.4.2). When the buoyant body arrives at the bottom of the settling stage (f.4.3), the valve is released creating a new fluid circuit from the balloon to the accumulator, filling the balloon with working fluid and starting to inflate it (f.4.3). f.4.4). Once filled with working fluid to obtain sufficient positive buoyancy for surfacing, the buoyant body begins to rise due to the positive buoyancy provided by the balloon (f.4.5). During the ascent, the buoyant body rotates the turbine rotor which connects with the turbine blades and electricity is generated (f.4.6). The ascent phase continues until the buoyant body approaches the water surface, at which point the working fluid from the balloon is pumped into the accumulator (f.4.7) and then the cycle is restarted.

Various modifications may be made to the embodiment of FIG. 5 to provide further embodiments. For example, the buoyant body 51 may have fixed pitch turbine blades or may be equipped with variable pitch blades. An advantage of variable pitch blades is that the pitch can be controlled to vary the drag on the turbine blades and thus the descent and ascent speeds and thus the power output.

Further, the buoyant body may be equipped with more than one set of turbine rotors, eg, counter-rotating blade sets. Such counter-rotating propeller-type systems have proven to be more efficient than single blade sets.

FIG. 6 shows a turbine blade pitch control mechanism for use with a turbine rotor. A gearing chamber 61 is formed in the turbine rotor 13 . The turbine blade 12 is equipped with a gear 62 at its root end and fixed in a rotatable manner in conjunction with the turbine rotor 13 . A root end gear 62 is connected to a rack bar 63 that controls rotational motion. Rack bar 63 is retained by root gear 62 and retaining gear 64 mounted in gear chamber 61 to achieve axial movement. Also, the rack bar 63 is slidably connected along the surface of a control ring 65 installed parallel to the turbine rotor 13 and rotates together with the turbine rotor 13 . The control ring can transmit axial motion to the rack bar 63 by an actuator (not shown) from inside. The actuator is capable of moving control ring 65 in proportion to the pressure on balloon 17 . In one embodiment, turbine blades (not shown) are directly coupled about the axis of rotation of root gear 62 . In another embodiment, the blade is connected to root gear 62 by rack bar 63, which may include gears. In both embodiments described above, axial movement of the control ring 65 by actuation of the actuator is coupled to movement of the rack bar 63 and rotation of the root gear 62 changes the pitch of the turbine blades 12 .

A single blade pitch control mechanism may control the pitch of a single turbine blade, or a single mechanism may control the pitch of multiple blades through mechanical linkage.

In yet another embodiment, the electrical control unit uses the twist produced by the blade pitch control mechanism to monitor the rate of climb and/or descent and control the angle of the turbine blades.

In another embodiment, the buoyant body 10 is equipped with a storage battery 51 inside the housing 14 to transmit power to an external device (e.g., UUV, USV, etc.) on the water surface or underwater without contact (e.g., electromagnetic induction, etc.). It may be possible to equip a feed coil 52 to power the .

Further modifications may be made to the above-described embodiments, either by additions, substitutions or deletions, to provide further embodiments, all of which fall within the scope of the appended claims. intended.

Claims (6)

A buoyant body equipped with a turbine rotor operable to rotate about the housing, the turbine rotor having permanent magnets on the turbine blade ends, and supported from the housing to support the turbine blade ends. having a circumferentially covering shroud and communicatively coupled to a power generation system having an excitation coil within the shroud or within the housing and arranged to generate power as the turbine blades rotate; a set of rotatable turbine blades;
a buoyancy control system arranged to controllably impart positive and negative buoyancy to the buoyant body and driven by a working fluid;
a control system for selectively activating one or more buoyancy control systems depending on the rate of ascent of the buoyant body;
A buoyant body, wherein said buoyant body is suitable for diving and said turbine blade set is arranged to rotate as it moves through the water by said buoyant body. 2. The buoyant body of claim 1, wherein the buoyancy control system comprises one or more hydrodynamically shaped deflatable balloons. 2. The buoyant body of claim 1, wherein the buoyancy control system comprises a fluid circuit in closed connection with a deflatable balloon, a pump for displacing a working fluid, and an accumulator capable of pressurizing and storing the working fluid. . the one or more first fluid circuits comprising one or more first circuits directed away from the surface of the water, the working fluid discharged from the one or more first accumulators comprising: 4. The buoyant body according to any one of claims 1 to 3, which increases the speed of ascent of the buoyant body. A system for storing potential and pressure energy of a buoyant body according to any one of claims 1 to 4, comprising:
the buoyant body is negatively buoyant at a lower limit of travel, and the buoyancy control system includes a pressure accumulator and a liquid pump arranged to inflate and deflate the balloon with liquid;
A system operable thereby to impart positive buoyancy to said buoyant body and to store potential and pressure energy within said system. A system for generating and storing electrical energy, comprising a turbine blade set according to any one of claims 1 to 5 and a buoyant body with an accumulator, comprising:
The primary buoyant body is provided with contact or non-contact power feeding means capable of supplying electrical energy to the outside,
A system thereby operable to be released from said power supply means when electrical energy is required from the outside.

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