WO2008053293A2

WO2008053293A2 - Device for converting sea wave energy into mechanical power

Info

Publication number: WO2008053293A2
Application number: PCT/IB2007/003078
Authority: WO
Inventors: Artem Valeriyovich Madatov; Oleksiy Petrovich Ostanin
Original assignee: Artem Valeriyovich Madatov; Oleksiy Petrovich Ostanin
Priority date: 2006-11-03
Filing date: 2007-10-16
Publication date: 2008-05-08
Also published as: WO2008053293A3

Abstract

The invention relates to wave energy, in particular to devices used for converting power of waves on a water surface, mainly sea and ocean waves, into useful mechanical power which can be used directly or converted into other types of energy, for example electric energy. The inventive device comprises a semisubmerged rotor (1) in the form of a plurality of cup-shaped reservoirs (7) which are cyclically and uniformly distributed around a substantially horizontal shaft (2) provided with rotation supports (3) and are rigidly connected to said shaft (2), a submersible rotor (4) which is designed in the form of a plurality of shaped blades (8) which a cyclically and uniformly arranged around another horizontal shaft (5) provided with rotation supports (6) and are rigidly connected thereto, wherein the rotation supports (3) of the semisubmerged rotor (1) are rigidly connected to the rotation supports (6) of the shaft of the submersible rotor (4) by means of a rigid frame (9). The invention makes it possible to efficiently extract wave energy at any length of a rotor.

Description

DEVICE FOR TRANSFORMING ENERGY OF SEA WAVES

IN MECHANICAL ENERGY

The invention relates to wave energy, in particular, to devices for converting wave energy on the surface of a reservoir, mainly sea or ocean waves, into useful mechanical energy, which can be used directly or converted to other types of energy, for example, electrical.

Known devices for converting wave energy on the surface of the water, containing a rotor mounted on the surface of the reservoir in the form of many semi-surface bucket containers that are cyclically uniformly placed around a generally horizontal shaft and rigidly connected to this shaft (WO 81/02329, FОЗВ 13/12, 1981 ; GB 2,110,763, FОЗВ 13/12, 1983; RU 2,065,078, FОЗВ 13/12, 1996). The axis of rotation of the rotor is located at the height of the average water level and is oriented along the direction of wave propagation. When the wave runs on, the bucket-shaped containers on one side of the rotor, with their mouths pointing upward (upward), are filled with water. The bucket-shaped containers on the other side of the rotor, with their mouths facing downward (pointing downward), remain filled with air and tend to float when the entire rotor is immersed in water, which creates a torque. When the wave rolls back down, the bucket-shaped containers are emptied, and the bucket-shaped containers directed upward remain filled with water, which also creates a torque directed in the same direction.

Such devices can only work effectively provided that the wave height exceeds the vertical size of the bucket capacity. Based on this requirement, the height of the bucket capacity should be less than the average wave height in this area. On the other hand, the energy efficiency of the device is directly proportional to the volume of the tank filled with water and, consequently, the height restrictions of the bucket-shaped tank causes a limitation of the energy efficiency of the device as a whole. In other words, if in order to obtain a given power of the device, its capacitance must have a height of 0.5 m, then this means that at a wave height of less than 0.5 m, the device stops completely. In this case, an installation with a height of capacities that does not exceed the average wave height in a given water area seems to be optimal. Such an installation will work almost uninterruptedly, but its specific power (power per unit of the total installation volume) is limited.

In the device according to WO 81/02329, known as the Winkranz rotor, shaft rotation bearings are attached to the bottom supports by cables to bottom supports, which limits the vertical and horizontal displacement of the rotor under the influence of waves and wind. The device also comprises a platform with an electric generator installed on it, the rotor of which is connected to a semi-surface rotor.

When the Vincranz rotor or its individual sections are periodically covered by waves, then, as described above, the bucket-shaped containers on one side of the rotor are filled with water, and on the other hand, are free of water, which creates a moment of force leading to the rotation of the rotor. The device operates most efficiently under conditions that the rotor length is equal to or greater than the sea wave length, in calm water the rotor is half immersed in water and its diameter is close to the wave height. Here, the wavelength refers to the horizontal distance in the direction of wave propagation between adjacent single-phase portions of the surface of the wave surface, for example, between the vertices of two adjacent waves. Under these conditions, each of the sections of the rotor periodically passes through the phases of complete or almost complete immersion in water and complete or almost complete exit from the water, and the theoretically possible maximum energy extraction of the wave is achieved. The lengths of wind waves are usually within 20-50 m, and the so-called “Swell” - 50-120 m. Thus, the minimum length of the Winkranz rotor should be from 20 to 50 m. Moreover, the rotor design must withstand large mechanical loads that occur when exposed to sea or ocean waves. Given the actual operating conditions, the design of such a length, ensuring the strength of the rotor requires special solutions and the use of particularly strong materials, as a result of which the cost of the device increases so much that its operation becomes unprofitable.

The objective of the present invention is to provide a device for converting the energy of sea waves into mechanical energy of the rotor type, in which, at any length of the rotor, efficient selection of wave energy will be provided.

The problem is solved in that the device for converting the energy of sea waves into mechanical energy, containing a full-wave rotor in the form of a plurality of bucket-shaped containers that are cyclically uniformly placed around a generally horizontal shaft with rotation bearings and are rigidly connected to this shaft, is characterized in that it contains an underwater a rotor made in the form of a plurality of profiled blades that are cyclically uniformly placed around another horizontal shaft with rotation bearings and are rigidly connected to this shaft, p and this rotation support shaft polunadvodnogo rotor rigidly connected with the supports of the rotation shaft of the rotor by means of underwater rigid skeleton.

Preferably, the shaft of the semi-surface rotor is kinematically connected with the shaft of the underwater rotor, which makes it possible to coordinate the rotational speeds of both rotors and summarize the torques created by them.

This kinematic connection of the rotor shafts can be made in the form of a crank mechanism. The device is expediently made in the form of two identical pairs of a semi-surface rotor and an underwater rotor, the rotation bearings of which are rigidly interconnected by means of a common rigid frame.

With such an embodiment of the invention, the shafts of all rotors can also be kinematically connected to each other using, for example, a crank mechanism, which ensures consistent rotation of all rotors and summation of the torques created by them.

Preferably, the bucket-shaped containers and shaped blades of the rotors of one such pair are mirrored with respect to the bucket-shaped containers and shaped blades of the corresponding rotor of the other pair, which ensures the opposite direction of the torques created by them and the horizontal stability of the whole structure.

Ensuring a synchronous and opposite direction of rotation and summing of torques can be achieved by means of surface and underwater rotors mounted on the shafts of the first and second pairs of gears engaged with each other.

The most appropriate form of rotors is a cylinder with a length of 5 to 80 m. Short rotors (5 - 8 m) are very resistant to high waves and wind loads, and, accordingly, are most suitable for use in areas where severe storms are possible. In bays, lagoons, bays, etc., protected from stormy winds and waves. installations with longer rotors up to 80 m long can be used.

The bucket-shaped containers and / or profiled blades can be made of elastic material, which makes it possible to change their shape depending on the direction of the incoming water flow, in particular, to expand to the maximum volume when the water flow runs onto the container or blade from the inlet side, and wrinkle to a minimum volume in the opposite direction of the oncoming flow of water. Since in the process the rotors will be located mainly along the direction of wave propagation, it is preferable that the inlet openings of the bucket-shaped containers are at least partially facing the end of the rotor directed towards the waves.

In more detail, the device is described below using the drawings, which show:

- FIG. 1 is a schematic illustration of an installation with one pair of rotors;

- FIG. 2 is a schematic illustration of a four-rotor installation; FIG. 3 - kinematic diagram of a four-rotor installation; FIG. 4 - kinematic diagram of an eight-rotor installation;

In the simplest embodiment, the device for converting the energy of sea waves into mechanical energy comprises a semi-surface rotor 1 with a shaft 2 installed in the bearings of rotation 3, and an underwater rotor 4 with a shaft 5 installed in the bearings of rotation 6 (Fig. 1). The surface rotor 1 is made in the form of a plurality of bucket-shaped containers 7, which are cyclically uniformly placed around the shaft 2 and are rigidly connected with this shaft. The underwater rotor 4 is made in the form of a plurality of profiled blades 8, which are cyclically uniformly placed around the shaft 5 and are rigidly connected with this shaft. The rotation supports 3 of the surface rotor 1 are rigidly connected to the rotation supports 6 of the underwater rotor 4 by means of a rigid frame 9. The surface rotor 1 and the underwater rotor 4 are equipped with cranks 10 and 11, respectively, which are interconnected by a connecting rod 12.

The inlet openings (mouths) of the bucket-shaped containers are at least partially facing the end of the surface of the rotor, which in working condition is facing towards the shaft.

Both bucket-shaped containers and profiled blades can be made of flexible, resistant to repeated bending material, for example, from fabric-reinforced sheet rubber, polymer plates, and the like. (not shown in FIG.).

The outer diameter D of the semi-surface rotor 1 is chosen so that it is approximately equal to the average wave height H characteristic for a given water area, and the circumferential size h of bucket-shaped containers on the periphery of the rotor 1 is chosen so that it is knowingly smaller than this wave height. The height L of the rigid frame 9 may be 2H or more; preferably, it should be greater than the depth to which the disturbances caused by the wave propagate. In this example, the rotor length is significantly less than the wavelength.

In working condition, the device is placed in water and attached by cables to coastal or bottom supports to exclude uncontrolled horizontal movement (not shown in FIG.). The axes of rotors 1 and 4 are generally horizontal and along the direction of wave propagation in a given water area. The semi-surface rotor 1 is in a semi-submerged state on the surface of the water, in the underwater rotor 4 is completely submerged in water and is located in the region of relatively calm water, where the amplitude and phase of the vertical movements of the water layers are insignificant or differ from the amplitude and / or phase of wave oscillations on the surface of the reservoir. Since the rotor length is much shorter than the wavelength, we can assume that at any time all sections along the rotor are at the same depth.

When the wave rolls along the semi-surface rotor 1, the rotor is immersed in water to the maximum depth (the position of the water level relative to the rotor 1 in this phase is shown by the MAX line) and to the minimum depth (the position of the water level relative to the rotor 1 in this phase is shown by the MIN line).

When the position of the water level relative to the semi-surface rotor 1 is minimal, the bucket-shaped containers 7 on one side of the rotor, facing upwards (directed upwards) are completely or partially filled with water from the previous wave, and on the other side of the rotor these containers are free of. water, since they are turned with their mouths downward (directed downward). On the lateral sides of the rotor, a mass difference occurs, which creates a torque that tends to rotate the rotor in the direction of the water-filled containers 7 (counterclockwise in Fig. 1).

When the wave runs onto this section of the rotor 1, the water level rises relative to it, the bucket-shaped containers 7 directed upward by the mouths are filled with water on one side of the rotor and have zero or negative buoyancy. At the same time, the bucket-shaped containers 7 directed downward on the other side of the rotor remain filled with air and, when immersed in water, acquire positive buoyancy, i.e. tend to come up. Thus, a buoyancy difference is generated on the sides of the rotor 1, which creates a torque also counterclockwise in FIG. one.

When the wave decays, the water level relative to this section of the rotor 1 decreases, the bucket-shaped containers 7 directed upward on one side of the rotor remain filled with water, the bucket-shaped containers 7 directed downward on the other side of the rotor are empty. Again, a mass difference arises on the sides of the rotor, which creates a torque that tends to rotate the rotor counterclockwise.

If the bucket-shaped containers face their mouths towards the incident wave, an additional torque arises due to hydrodynamic pressure on the side wall of the containers.

If the bucket-shaped container is made of elastic material, then when the water flow runs from the inlet side, the container is straightened and its volume becomes maximum. In the opposite direction of the oncoming flow of water, the capacity is crushed by this flow and its volume becomes minimal, which allows to realize the maximum the possible difference in forces applied to diametrically opposed capacities and get the maximum torque.

Since the installation as a whole has positive buoyancy, when the water level rises and falls, the entire structure of the installation tends to rise and fall relative to the bottom of the reservoir simultaneously with a change in the water level, i.e. just swim on the surface of the waves. If this is allowed, then the water level will not change relative to the semi-surface rotor or it will be minimal and, accordingly, the installation will not work or will work extremely inefficiently. This is prevented by the underwater rotor 4, which is deeper or on the boundary of the disturbance zone caused by the waves, is rigidly connected to the semi-surface rotor 1 by the frame 9. When the water level relative to the semi-surface rotor 1 changes and the installation tends to change its vertical accordingly, the underwater rotor 4 encounters resistance water to its movement and slows down this process, although it does not completely stop it, thanks to this installation, although it performs oscillatory movements in the vertical direction, but the amplitude Yes, these fluctuations are significantly less than the height of the waves. Due to the shape of the blades 8, the movement of the underwater rotor 4 generates a torque that is added through the crank 11, the connecting rod 12 and the crank 10 to the torque from the semi-surface rotor 1. The total moment can be transferred to the load, for example, to an electric current generator installed on a floating platform, using conventional mechanisms, such as, for example, a chain drive, a gear reducer, a crank mechanism, a flexible shaft, etc.

Such a two-rotor installation will work efficiently at both shorter and longer wavelengths. In practice, the installation length should be chosen as large as possible, taking into account the restrictions imposed by costs, rapidly growing with increasing length. The interaction of the rotating rotors of the two-rotor installation with water leads to the emergence of a horizontal force, which tends to shift the installation in the direction of rotation of the rotors. To compensate for this effect, it is advisable to combine two pairs of rotors in Fig. 1 in one installation. The kinematic diagram of such a four-rotor installation is shown in FIG. 2. This installation fully includes the design described above, which is supplemented by a second semi-surface rotor 13 with bucket containers 14, a shaft 15, a rotation support 16 and a crank 17, and a second underwater rotor 18 with blades 19, a shaft 20, a rotation support 21 and a crank 22. The rotation bearings 16 and 21 are rigidly connected to the frame 9 common to the entire installation. Cranks 17 and 22 are kinematically connected to each other by a connecting rod 23. At least one of the mechanism elements of the second pair of rotors is rotor 13, rotor 18, crank 17, crank 22 or connecting rod 23 - kinematically connected with one of the elements of the mechanism of the first pair of rotors - rotor 1, rotor 4, crank 10, crank 11 or connecting rod 12. One of the possible schemes for the kinematic connection of these elements is shown in FIG. 3. The bucket-shaped containers 14 of the rotor 13 are mirror-oriented with respect to the bucket-shaped tanks 7 of the rotor 1, and the blades 19 of the rotor 18 are mirror-oriented with respect to the blades 8 of the rotor 4.

The second pair of rotors 13 and 18 works similarly to the first pair of rotors 1 and 4, with the only difference being that the direction of rotation of the second pair of rotors 13 and 18 is opposite to the direction of rotation of the first pair of rotors 1 and 4. As a result, the horizontal forces that arise from the interaction of the rotating with water each pair of rotors will be directed in opposite directions and will compensate each other, thereby achieving much greater horizontal stability of the four-rotor installation in comparison with the two-rotor installation.

In FIG. 3 shows a simplified kinematic diagram of a four-rotor installation, in which semi-surface rotors are kinematically connected with each other and with the load indicated by 24, by means of a gear transmission. This design provides a summation of all the torques generated by the rotors and the transmission of the total torque to the load.

The power of the entire installation can be increased by further increasing the number of pairs of rotors placed on a common rigid frame. In FIG. 4 shows a kinematic diagram of an eight-rotor installation in which four more rotors 25, 26, 27 and 28, similar to the first four rotors, are added to the previously described four-rotor structure. A semi-surface rotor 25 is kinematically connected by a connecting rod 29 to an underwater rotor 26 and a connecting rod 30 is connected to a semi-surface rotor 1. The underwater rotor 28 is kinematically connected by a connecting rod З l to a semi-surface rotor 27, and a connecting rod 32 - by an underwater rotor 18.

It is clear that the number of such pairs can be further increased to a reasonable size from an engineering point of view.

Thus, the presence of an underwater rotor connected by a rigid frame to a half-rotor rotor provides the possibility of efficient selection of sea wave energy into mechanical energy for any length of the rotor. Compared to the Winkranz rotor installations according to the invention, especially with elastic bucket containers, can be increased by 2 times (up to 50%) due to the fact that semi-surface rotors are completely immersed in water, the number of bucket containers filled with water at any time doubles. Moreover, the efficiency installation according to the invention does not depend on the wavelength at sea.

A qualitatively new effect is:

Reducing the dimensions and material consumption of the structure due to the shortening of the rotors and the exclusion of the brake disc;

Reducing the energy loss due to friction of crushed (folding) ladles of containers made of elastic material - rubber or plastic; Optimizing the proportions of the frame (reducing the ratio of length to width and height), which increases the mechanical resistance of the structure to deformation;

A decrease in the minimum wave amplitude at which the installation begins to work and an increase in torque and efficiency rotors with elastic bucket-shaped containers by reducing rotation resistance due to the use of folding (crumpled) bucket-shaped containers;

Increase in efficiency installations through the use of an effective hydrodynamic brake - underwater rotors;

Increased stability of the wind turbine to capsize by large waves due to the location of the center of gravity of the structure below the water level.

Claims

Claim

1. A device for converting the energy of sea waves into mechanical energy, containing a semi-surface rotor in the form of a plurality of bucket containers, which are cyclically uniformly placed around a generally horizontal shaft with rotation bearings and are rigidly connected to this shaft, characterized in that it contains an underwater rotor made in in the form of a plurality of profiled blades that are cyclically uniformly placed around another horizontal shaft with rotation supports and are rigidly connected to this shaft, while the rotation shaft supports are half aqueous rotor rigidly connected with the supports of the rotation shaft of the rotor by means of underwater rigid skeleton.

2. The device according to p. 1, characterized in that the shaft of the semi-surface rotor is kinematically connected with the shaft of the underwater rotor to coordinate the rotation of the rotors and summarize the torques created by them.

3. The device according to p. 2, characterized in that the kinematic connection of the shafts of the rotors is made in the form of a crank mechanism.

4. The device according to p. 1, characterized in that it has a second identical pair of semi-surface rotor and underwater rotor, while the rotor bearings of the second pair are rigidly connected to the rotational bearings of the rotors of the first pair by means of a common rigid frame.

5. The device according to p. 4, characterized in that the shafts of all the rotors are kinematically connected to each other to ensure a coordinated rotation of all the rotors and to summarize the torques created by them.

6. The device according to p. 4, characterized in that the bucket-shaped containers and profiled blades of the rotors of the second pair are oriented mirror-wise to the corresponding bucket-shaped containers and shaped blades of the corresponding rotor of the first pair.

7. The device according to one of claims 1 to 6, characterized in that the rotors are generally in the form of elongated cylinders with many bucket containers on the side surface.

8. The device according to claim 7, characterized in that the length of the cylinders is 5 to 80 m

9. The device according to claim 6, characterized in that to ensure synchronous and opposite direction of rotation and the summation of the torques, on the shafts of the surface or underwater rotors of the first and second pairs are installed gears meshing with each other.

10. The device according to claim 7, characterized in that the bucket-shaped containers and / or profiled blades are made of elastic material with the ability to change their shape depending on the direction of movement of the incoming water flow.

11. The device according to one of claims 1 to 10, characterized in that the inlet openings of the bucket-shaped containers are at least partially facing the end of the surface rotor facing the waves.