Underwater / above-water floating wave power plant

Abstract

The invention relates to the field of renewable energy engineering, and more particularly to the use of floating wave power plants in marine energy engineering. The invention can be used for supplying power to consumers located in coastal zones or on the surface of large bodies of water. What is proposed is a floating wave power plant designed so that a buoy can be submerged below the water in the event of rough seas to protect the structure against the destructive effects of wave dynamics and so that said buoy can resurface in the event of calm seas. In addition, to increase productivity, each of six actuators comprises a power take-off system with a rotary electric generator. The invention is intended to protect the structure against the destructive effects of waves and to increase the productivity of a floating wave power plant.

Description

[0001] Underwater and surface floating wave power plant

[0002] The invention relates to energy, in particular to wave energy, and can be used to supply energy to consumers located on large bodies of water and on their coasts.

[0003] An underwater wave power plant proposed in the invention [KS Sholanov. Power plants (variants) based on a parallel manipulator. WO 2018 / 147716, 16.08.2018] is adopted as an analogue for the power plant. The proposed floating wave power plant (FWP) utilizes a SHOLKOR six-moving parallel manipulator (KS Sholov. Parallel Manipulators of Robots. Theory and Applications. Springer, 2021. ISBN 978-3-030-56073-7) as the primary wave energy converter to convert the spatial movements of underwater water masses. A hollow float consisting of two cavities separated by a flexible diaphragm is also used to control the float's buoyancy in the underwater FWP. One of the cavities (the upper one) is a sealed container filled with air (gas), while the other (the lower one) is filled with water as needed. The float's buoyancy is changed by pumping water into the cavity or by exhausting it.A disadvantage of the existing design is that the float is constantly submerged, and during light surface disturbances, the float doesn't sense the movement of the water mass at depth, reducing the power plant's performance. The prototype chosen was the underwater float-powered wave power plant proposed in the invention (KS Sholov, "Controllable Underwater Wave Power Station." WO / 2022 / 225382, October 27, 2022). The prototype proposes a floating underwater wave power plant (FWP) that uses a SHOLKOR six-moving parallel manipulator as the primary wave energy converter. The prototype also proposes actuator damping control to vary the power plant's performance depending on wave height. Additionally, a power take-off system is used in three actuators, converting the reciprocating motion of the actuators into rotational motion of the built-in electric current generators.A drawback of the prototype is that the float remains permanently submerged beneath the water's surface, even in gentle waves. Another drawback is that only three actuators are involved in generating the electric current.

[0004] The technical objective of the invention is to protect the power plant from the destructive effects of waves during strong waves and to increase the productivity of the power plant during weak waves on the water surface, as well as to increase the productivity of the power plant as a whole.

[0005] This invention proposes a controlled underwater-surface wave power plant comprising the following known features: a six-movable manipulator converter SHOLKOR, actuator damping control, and a power take-off system.

[0006] To address the technical challenge of protecting the floating wave power plant (FWP) during heavy seas and increasing productivity during light waves, a FWP design is proposed in which the float's depth can be varied from above the water in light seas to submerged at a predetermined depth in high waves. To achieve this, the upper platform of the floating wave power plant (FWP) is designed as a hollow ellipsoidal float with positive buoyancy, while the lower movable platform is a sealed container with a durable body consisting of two cavities separated by a flexible diaphragm. One of the cavities is a sealed container filled with air (gas), while the other is filled with water. By injecting water into this cavity during strong waves, negative buoyancy of the entire structure is achieved, causing the float to submerge deeper.In light waves, water is expelled from the tank to increase buoyancy until the float floats above the water. The lower platform has an elliptical shape to reduce hydrodynamic drag, as well as vertical and horizontal ribs to ensure platform stability. The lower platform of the manipulator converter is secured to the bottom of the reservoir using six cables (ropes), following the SHOLKOR parallel manipulator actuator connection scheme. Each cable has a self-tensioning device to prevent cable tangling.

[0007] To address the technical challenge of increasing the overall performance of the solar power plant, each of the six actuators is designed with power takeoff systems and rotary electric current generators. All six actuators are housed in sealed housings to protect them from harmful environmental influences.

[0008] Figure 1 shows an underwater-surface float wave power plant consisting of a float 1, representing the upper movable platform of the manipulator converter, and a lower movable platform 2 connected by six actuators 3 according to the connection scheme of the SHOLKOR parallel manipulator. The actuators are connected to each other and to the platforms by means of spherical joints 4. The lower platform 2 is connected to a fixed base 5 on the bottom of the reservoir by means of cables (ropes) 6. Each rope has a self-tensioning device 7. Vertical 8 and horizontal ribs 9 are attached to the body of the lower platform with a hydrodynamic shape. Figure 2 shows the design scheme of the lower platform, which has a two-cavity structure consisting of a rigid shell 10 and a flexible diaphragm 11. The diaphragm separates the gas-filled upper cavity 12 from the cavity 13 filled with water.A hydraulic pump and exhaust solenoid valve 14 are built into the fluid reservoir, as well as a hydraulic pump 15 that pumps water. A pressure sensor 16 is installed in cavity 12, occupied by gas. Figure 3 shows the actuator design. The actuator consists of a moving part and a relatively fixed part. The moving part includes a carriage consisting of an upper 17 and lower 181 plate connected to rod 19 and flange 1 of the float. The relatively fixed part is formed by rigidly connected plates 20, 21, 22 and shaft 23. It should be noted that the term "relative" is used because this part forms a multi-link spherical connection with the moving platform MP-1 via spherical joints. The movement of the movable carriage relative to the fixed part is limited from above by a spring 24, and from below by a spring (damper) 25, forming a controlled damping system due to an electric motor 26 controlling the pre-tension of the spring 24.Mounted on shaft 23 are overrunning clutches 27, onto which are mounted drums 28, connected via cables 29 to the carriage plates. Shaft 23, the cable mechanism, and the belt drive with pulleys 30, 31, and flexible coupling 32 form the power take-off system (PTS). The PTS converts the reciprocating motion of the carriage along guides 33 into rotational motion in one direction (via the overrunning clutches) of the generator shaft 34.

[0009] The operating principle of the underwater-surface wave station is based on the fact that, at wave heights lower than the most common (nominal) values, float 1 (Fig. 1) is located on the water surface, has a streamlined hull, and is positively buoyant. Lower platform 2, like the underwater vehicle, must meet the following requirements: withstand water pressure while submerged, ensuring a strong and watertight hull, have automatic control devices for diving and surfacing to change depth, and have a streamlined hull. When wave heights exceed the nominal value, float 1 must be submerged to prevent damage from wave dynamics. In this case, water is pumped into cavity 13 using a hydraulic pump. This compresses the air in cavity 12. When the air compression reaches its maximum, sensor 16 is triggered, and water intake ceases. The float submerges to a depth equal to the difference between the actual and nominal wave heights.After reaching the required depth, the lower platform achieves the required buoyancy to maintain the desired depth and ensure system stability. If the actual wave height is less than the nominal height, the system resurfaces. To ensure positive buoyancy and float resurfacing, water is expelled from cavity 13 using an exhaust valve and a hydraulic pump. The released volume changes the position of the diaphragm, which, using compressed air, increases the volume of cavity 12. It should be noted that the lower platform's size is initially calculated to ensure neutral buoyancy and, with the shortest actuator length, float 1 is located on the water surface. After the float resurfaces, the lower platform has neutral buoyancy.

[0010] All actuators in the upper and lower units form spherical joints 4 among themselves, as well as with the float and lower platform (as in the SHOLKOR parallel manipulator). The lower platform 2 is connected to the bottom 5 of the reservoir via six cables 6, following the SHOLKOR manipulator connection scheme. These cables limit the platform's upward movement, thereby ensuring the desired immersion depth. As the lower platform descends, the cables 6 are shortened in length by self-tensioning devices, thereby preventing cable tangling. To prevent rotational motion and oscillation, the lower platform is equipped with four vertical ribs 8 and four horizontal ribs 9, arranged symmetrically.

[0011] The operating principle of the manipulator is illustrated by Figure 3. The action of the moving water mass on the float (the upper platform of the manipulator) changes the lengths of the six actuators 3, resulting in a reciprocating motion of the carriage made of plates 17 and 18 along guides 33, which causes the shafts of generators 34 to rotate, generating electric current from the six generators. In the initial position of the float (when the water surface is calm), the load from the float acts on the actuator, which is supported by damper 25 and the tension force of spring 19. The tension force can be varied using controlled drive 26, which allows setting the float sensitivity. The power take-off system (PTS) converts the reciprocating motion of the carriage into rotational motion of the generator shaft. PTS consists of two cables 29 connected at one end to the upper plate 17 of the carriage and at the other end to the lower plate 18 of the carriage.Both cables are wound onto two drums 28, which are connected to the shaft via two overrunning clutches, ensuring rotation of shaft 23 in one direction, regardless of the direction of movement of the carriage. This rotation is transmitted via pulleys 30 and 31 to the shaft of generator 34. The reciprocating motion of the carriage is thus converted into rotation of the generator shaft, which generates electric current. Thus, depending on the spatial movement of the float, the movements of six actuators are controlled, the generators of which generate electric current. As a result, the float of the underwater-surface wave power plant, located either underwater or above water (depending on wave height), responds to all spatial movements of water particles and generates electric current via six electric current generators.

Claims

CLAUSES OF THE INVENTION 1. An underwater-surface float-type wave power plant (USFWP) comprising a manipulator converter connected according to the SHOLKOR manipulator circuit with six actuators, as well as a hollow float with an aerodynamic cross-section profile, characterized in that, in order to protect the wave power plant from the destructive dynamics of waves in strong waves and to increase productivity in weak waves, a design of a wave power plant is proposed in which the upper platform of the manipulator converter is made in the form of a hollow ellipsoidal float with positive buoyancy, and the lower movable platform is made in the form of a sealed container with a body made of durable material consisting of two cavities separated by a flexible diaphragm, wherein one of the cavities is a sealed container filled with air (gas),and the other cavity is filled with water and allows, by changing the volume of water, to change the immersion depth of the float and the wave power plant as a whole.

2. An underwater-surface floating wave power plant according to paragraph 1, characterized in that the lower platform of the manipulator converter is attached to the bottom of the reservoir using six cables (ropes) according to the connection diagram of the SHOLKOR parallel manipulator actuators, wherein each of the cables has self-tensioning devices to prevent the cables from tangling.

3. An underwater-surface floating wave power plant according to paragraphs 1 and 2, characterized in that the lower platform has an ellipsoid shape to reduce hydrodynamic resistance forces, as well as symmetrically located vertical and horizontal ribs to ensure a stable state of the platform.

4. Underwater-surface floating wave power plant comprising a manipulator converter connected according to the diagram connections of the SHOLKOR manipulator and containing six actuators, characterized in that, in order to increase the productivity of the PNPWLES, power take-off systems with generators of electric current of rotary motion are introduced into the design of all six actuators.

5. An underwater-surface floating wave power plant according to paragraph 4, characterized in that each actuator is equipped with a sealed housing for protection from the harmful effects of the environment.

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