WO2020209753A1

WO2020209753A1 - Wave energy converter

Info

Publication number: WO2020209753A1
Application number: PCT/RU2020/000113
Authority: WO
Inventors: Денис Михайлович БОГДАНОВИЧ
Original assignee: Денис Михайлович БОГДАНОВИЧ
Priority date: 2019-04-11
Filing date: 2020-03-04
Publication date: 2020-10-15

Abstract

The invention relates to wave energy converters. A converter consists of an elongated floating buoy, a submerged lower supporting buoy, a generator compartment and a power take-off mechanism which can be set into action with rigid tie rods that are capable of sliding in guides, and a single-point anchoring system. The compartment is arranged on the floating buoy. Two identical coaxial shafts emerge from the mechanism, one from each of the long sides of the buoy. The two tie rods are in the shape of a fork and are fastened in the upper part to each of the shafts using contra-rotating ratchet mechanisms. Inclined guides each allow free sliding of the lower part of one of the tie rods, and converge in the upper part above the centre of the supporting buoy and are fastened to the supporting buoy in the lower part. The supporting buoy has a circular cross section in a horizontal plane. The anchoring system is attached to the wave energy converter at a single point – the central lower point of the supporting buoy. The invention is focused on operation during the rise and fall of a wave and on using the potential and kinetic energy of the wave.

Description

WAVE ENERGY CONVERTER

Technology area

[0001] The present invention relates to the field of hydraulic machines immersed in water, using the movement of a wave-driven element relative to another element, namely, a float-type wave energy converter designed to obtain energy from the movements of water waves when positioned beyond the coastline.

State of the art

[0002] A large number of different types of float converters of wave energy into electrical energy are known. Most of them require the use of devices that compensate for movement during wave growth, such as counterweights (WO 2013052447 2013-04-11), mechanical (WO 2007130525 2007-11-15) or pneumatic springs (GB 2540615 2017-01-25), which leads to losses in the volume of used wave energy. Other solutions address rigidly fixed foundations on the ocean floor (eg, WO 2016195600 2016-12-08), which increases the cost of the transducer as it requires additional sub-structural elements to strengthen the structure in high wave conditions. In addition, this design requires a solution to the problem of orientation of the transducer in the direction of wave propagation.

[0003] EP 2245299 2015-04-08 describes a transducer that uses an inertial counterweight in combination with a floating buoy, whereby energy is captured by moving the buoy towards the opposite side of the inertial mass using hydraulic cylinders or hose pumps. In any case, some of the trapped energy will be used to restore the position of the inertial mass relative to the buoy, thus reducing the efficiency of the transducer.

[0004] EP 2094966 2016-08-03 uses a floating base to house the generator and fix the buoy (active float) to capture wave energy. This transducer works in the same way as the inertial interaction of an active float and a jet body with waves. When the frequency of the waves decreases, the efficiency of the converter is significantly reduced, including due to a decrease in the difference in the response of the active and reactive parts.

[0005] Other solutions, such as those sold by Ocean Power Technologies, generate power by varying the responses of the float and platform equipped with a heavy plate to increase inertia to wave action.

[0006] Known marine wave power plant, according to US 4258270 A 1981-03-24 (column 6, paragraph 4), representing two floating bodies, one of which is the reference, and the second is working. The working body is attached to the support body in the plane of wave propagation in such a way that, under the action of the incident flow, it deviates up and back, making movements along a part of the circle with the center at the point of attachment of the working body to the reference body, while the rear surface of the working body is made corresponding to such a circle for the purpose to minimize the resistance of water in the space between the working and supporting bodies to the movement of the working medium. [0007] The use of the potential wave component is not key for this solution, since in order to effectively use the difference in water level during the rise and fall of the wave (at a typical wavelength of tens of meters), the centers of gravity of the floating working and floating support bodies must be significantly separated from each other. along the axis of wave propagation. For positioning the device, according to US 4258270 A, a single-point attachment system to the bottom and a multi-point attachment system to the converter itself are used.

[0008] Such a system allows the structure to be oriented in the direction of predominant propagation of waves, but poorly compensates for the negative effects of individual irregular waves, the direction of which differs from the direction of predominant propagation. This is due to the relatively large distance of the structure from the attachment point at the bottom and, accordingly, the need for a large displacement of the entire structure to change the angle of perception of waves. (To compensate for this shortcoming, the author intends to make the converter as a whole from individual elements with some freedom of movement relative to each other using elastic couplings).

[0009] There is a need for a wave energy converter that is not diminished in efficiency by moving parts and that is capable of accommodating changes in wave direction without consuming the full potential of the wave energy, namely:

easy to navigate in the prevailing direction of wave propagation;

work on the surface or in the near-surface layer of water;

work in the direction of propagation of both potential and kinetic wave energy; have the most rigid point of support of the working fluid and, at the same time, the ability to compensate for the negative effects of waves that cannot be disposed of;

work both with the growth of the wave and with its decline;

generate electrical energy directly at the converter for its subsequent transfer to the shore.

The essence of the utility model

[0010] The technical problem of the present utility model is the creation of a wave energy converter with a float and reference buoys, intended for placement outside the coastline, which is oriented in the prevailing direction of wave propagation, works both with the growth of the wave and with its decay, and uses the potential, and the kinetic energy of the wave, easily deflected under extreme wave loads, protecting structural elements from destruction, generates electrical energy directly for its subsequent transfer to the shore.

[UN] The technical solution to the problem is that the wave energy converter consists of an elongated float buoy, a permanently submerged lower reference buoy, a generator compartment and a power take-off, driven by rigid rods, slideable in guides, a single point anchoring system. The novelty is that the compartment of the generator and the power take-off mechanism is located on the float buoy, and two identical coaxial shafts are removed from the mechanism, one on each of the long sides of the buoy, two rigid rods, shaped like a fork, are fixed in the upper part on each of the shafts with counter-rotating ratchets, inclined guides ensuring each free sliding of the lower part of one of the rods, converge in the upper part above the center of the support buoy and are fixed on the support buoy in the lower part, the support buoy has a circular cross-section in the horizontal plane, the anchoring system is attached to the wave energy converter at one point - the central lower point of the support buoy.

[0012] The essence of the utility model is illustrated by drawings and illustrations, where

in FIG. 1 schematically shows a wave energy converter, frontal view;

in FIG. 2 - the same, side view;

in FIG. 3 schematically shows the effective trajectory of the wave energy converter;

in FIG. 4 is a graph of the effective trajectory of the wave energy converter;

in FIG. 5 - possible effects of waves on the wave energy converter; in FIG. 6 is a photographic image of a prototype wave energy converter.

[0013] The main parts of the converter are:

upper, oblong-shaped float buoy 1;

a power take-off mechanism with a generator, located in compartment 2 at the top and in the center of the float buoy, and two coaxial shafts 3 are removed from the mechanism - one above each of the long sides of the buoy 1, perpendicular to these sides;

two rigid rods 4, made in the form of a fork, fitted with the upper ends on each of the above shafts 3, and the lower ends freely sliding in opposite guides 5; converging above the center of the support buoy symmetrically located inclined guides 5, each providing free sliding of the lower end of one of the rods 4;

lower, permanently submerged, support buoy 6, which has a circular cross-section in the horizontal plane (for example: a cylindrical or conical buoy), and on which the lower ends of the guides 5 are rigidly fixed;

single point anchoring system 7, attached to the center lower point of the reference buoy 6.

[0014] The specified structure independently orients itself in the prevailing direction of wave propagation due to the action of the kinetic component of the wave on the elongated upper buoy 1, in the practice of navigation, this effect is called "turn lag on the wave". At the same time, a support buoy 6, circular in horizontal section, rods 4, guides 5 and a single-point anchor system 7, provide minimal resistance to such an orientation.

[0015] The upper float buoy 1, located on the water surface, absorbs both the potential energy of the wave (moving upward with the growth of the wave and downward under the influence of its own weight when it decays) and kinetic (the wave roll-up, acting on the front vertical surface of the float buoy 1 , deflects the entire structure from the vertical axis). Due to this, the stroke of the float buoy 1 relative to the reference buoy 6 increases, as shown in FIG. 3 and FIG. 4. The movement of the rods 4, transmitting the useful force to the shafts 3 of the power take-off mechanism, while taking place in one plane, in which the resulting vector of wave energy is located. [0016] The lower support buoy 6, when the wave decays, creates a force that returns the entire structure to a vertical position and which is sufficient to operate the generator when the float buoy 1 moves downward under its own weight. As a result, the float buoy 1 approaches the reference buoy 6 as much as possible, generating energy at the wave decay.

[0017] If we consider other possible effects of waves on the float buoy 1 (Fig. 5), such as yaw, rocking about the transverse and longitudinal axes (roll and trim, respectively), sideways drift, we can see that, due to its design, the transducer easily deflects under their influence, avoiding extreme harmful loads. Roll and drift are compensated by the mobility of the lower ends of the rods 4 in the guides 5. The trim is converted into additional movements in the up-down and forward-backward directions, which is caused by the rigidity in the attachment points of the structural parts.

[0018] The fastening of the rods 4 on the shafts 3 of the power take-off mechanism is carried out using ratchet mechanisms of opposite rotation, which ensures the constant rotation of each shaft in one direction at any phase of the wave.

[0019] A variant of rigid fixation on the shafts of one rod and free fastening of another rod is possible, in which one of the rods is not involved in useful work, but plays a supporting role, and the direction of rotation of the shafts changes depending on the wave phase, providing the possibility of using a fundamentally different mechanism selection

POWER.

Claims

USEFUL MODEL FORMULA

A wave energy converter consisting of an elongated float buoy, a permanently submerged lower reference buoy, a generator compartment and a power take-off mechanism driven by rigid rods designed to slide in guides, a single-point armature system, characterized in that the generator compartment and the power take-off mechanism located on a float buoy, and two identical coaxial shafts are removed from the mechanism, one on each of the long sides of the buoy, two rigid rods, shaped like a fork, are fixed in the upper part on each of the shafts using ratchet mechanisms of opposite rotation, inclined guides that provide each free sliding of the lower part of one of the rods, converge in the upper part above the center of the support buoy and are fixed on the support buoy in the lower part, the support buoy has a circular cross-section in the horizontal plane, the anchoring system is attached to the wave energy converter at one point - the central lower point of the support buoy.

SUBSTITUTE SHEET (RULE 26)