Method for converting the energy of water waves into electricity by means of a wave power plant and a wave power plant

• US 9,447,770 B2
• Filed: 04/12/2013
• Issued: 09/20/2016
• Est. Priority Date: 11/17/2011
• Status: Active Grant

• Current Assignee: Wello Oy
• Original Assignee: Wello Oy
• Inventors: Paakkinen, Heikki, Paakkinen, Antti
• Primary Examiner(s): Patel, Tulsidas C
• Assistant Examiner(s): NGUYEN, VIET P
• Application Number:
  US14/394,721
• Publication Number:
  US 20150069760A1
• Time in Patent Office: 1,257 Days
• US Class Current: 1/1
• CPC Class Codes: E02B 9/08 Tide or wave power plants water-pressure machines, tide or wave motors F03B
• CPC Class Codes: F03B 13/16 using the relative movement between a wave-operated member, i.e. a "wom" and another member, i.e. a reaction member or "rem"
• CPC Class Codes: F03B 13/20 wherein both members , i.e. wom and rem are movable relative to the sea bed or shore
• CPC Class Codes: F03G 7/08 recovering energy derived from swinging, rolling, pitching or like movements, e.g. from the vibrations of a machine
• CPC Class Codes: Y02E 10/30 Energy from the sea, e.g. using wave energy or salinity gradient

Abstract

A method for converting the energy of water waves into electricity by means of a wave power plant, which comprises a floating body (1), a rotator (3) which is supported on the body and rotates around a rotator shaft (2) which is on average vertical, a gyro (5) which rotates around a gyro shaft (4) which is on average horizontal, the gyro and the gyro shaft rotating with the rotator around the rotator shaft (2), and at least one generator (6), which is connected to rotate together with the gyro or the rotator. By means of the rotator'"'"'s mass (M) is produced a moment rotating the rotator on the one hand by means of the inclination moment generated by the inclination of the body and gravitation, and on the other hand by means of the acceleration moment generated by the horizontal acceleration of the rotator shaft (2). The inclination and acceleration are caused by directing the internal flows of the wave at the submerged part of the body (1). The moment generated by gyro force is used to equalize the said inclination and acceleration moments during the revolution and the kinetic energy of the gyro is used as an energy reserve to equalize the effective output of the wave power plant.

Claims

1. A method for converting the energy of water waves into electricity by means of a wave power plant, which comprises a floating body, a rotator having a mass and said rotator being supported on the body and rotates around a rotator shaft which is on average in vertical or slightly inclined to the side, a gyro which rotates around a gyro shaft which is on average horizontal, the gyro and the gyro shaft rotating with the rotator around the rotator shaft, and at least one generator, which is connected to rotate together with the gyro or the rotator, the method comprising:

rolling the floating body by waves in step with the waves,

rotating the gyro around the gyro shaft,

wherein an inclination of the gyro shaft with respect to the horizontal plane is caused as a result of the rolling motion,

the rotation of the rotator is influenced by torque of the gyro, which follows from the inclination of the gyro shaft,

moments in the same direction as rotating the rotator by the rotator'"'"'s mass are produced at the same stage by the inclination moment generated by the inclination of the body and gravitation and by the acceleration moment generated by the horizontal acceleration of the rotator shaft,

said inclination and acceleration are caused by rolling the body in a direction deviating from the rolling direction according to the direction of the wave surface, which is achieved by directing the internal flows of the wave at the submerged part of the body, which is a mainly in vertical, or when in operation, inclined on average in the incoming direction of the wave, which is transverse to the direction of travel of the waves,

the lower part of the body is influenced by anchor force which takes part in inclining the body and causing acceleration,

the moment generated by gyro force is used to equalize the said inclination and acceleration moments during the revolution and the kinetic energy of the gyro is used as an energy reserve to equalize the effective output of the wave power plant, and

a phase lag of the rotation of the rotator, that is, the angle between the direction of the rotator and the direction of the inclination of the body is adjusted in such a way that the peak of the torque of the gyro coincides with the minimum point of the inclination and acceleration moments.

2. The method as claimed in claim 1, wherein the horizontal acceleration is enhanced by moving the level of an orbital track of the mass upwards to a distance equaling at least the radius of the orbital track from the roll axis of the body.

3. The method as claimed in claim 1, wherein the gyro is rotated at a speed of rotation which is more than 20 times greater than the speed of rotation of the rotator.

4. The method as claimed in claim 1, wherein the phase lag of the rotation of the rotator is adjusted by adjusting the generator load.

5. The method as claimed in claim 1, wherein the phase lag is adjustable within a range of 0-90 degrees to keep the direction of the rotator 0-90 degrees behind the direction of the inclination of the body.

6. The method as claimed in claim 1, wherein the output of the wave power plant is adjusted by varying the phase lag, that is, the angle between the direction of the rotator and the direction of the inclination of the body within 0-90 degrees and in addition by regulating the speed of rotation of the gyro.

7. The method as claimed in claim 1, wherein the gyro is rotated at a speed of rotation which is more than 40 times greater than the speed of rotation of the rotator.

8. The method as claimed in claim 1, wherein the phase lag is adjustable within a range of 60-90 degree to keep the direction of the rotator 60-90 degrees behind the direction of the inclination of the body.

9. A wave power plant comprising:

a floating body,

a rotator which is supported on the body and rotates around a rotator shaft which is on average vertical or slightly inclined to the side,

a gyro which rotates around a gyro shaft which is on average horizontal, the gyro and the gyro shaft rotating with the rotator around the rotator shaft, and

at least one generator, which is connected to rotate together with the gyro or the rotator,

wherein;

the submerged part of the body is a mainly in vertical, or when in operation, the body inclined on average in the incoming direction of the wave, which is transverse to the direction of travel of the waves and the wave extends so deep down that the internal flows of the wave occurring at different heights of the body which cause the body to incline in a direction deviating from the rolling direction according to the direction of the wave surface,

the rotator is located in the upper part of the body and an anchoring point in the lower part of the body to utilize an anchor force for producing a movement of the body,

the rotator comprises a mass, the center of gravity of which is at a distance from the rotator shaft, and an orbital plane of an orbital track of the said center of gravity is at least at said distance from the anchoring point of the body, whereby when the body inclines, the mass generates cophasal torques by the effect of both gravity and the horizontal acceleration of the rotator shaft in order to rotate the rotator,

the gyro is arranged to be used as an equalizer of the said torques during the revolution and as an energy reserve to equalize the effective output of the wave power plant, and

the generator is located on the gyro shaft or connected to be driven by the gyro shaft, and the outer end of the rotator, which is at a distance from the rotator shaft, is provided with a small wheel on which the outer end of the rotator rests and which rotates along a circular track which surrounds the rotator shaft coaxially.

10. The wave power plant as claimed in claim 9, wherein the gyro is arranged to be rotated at a speed of rotation which is more than 20 times greater than the speed of rotation of the rotator, and

the speed of rotation of the gyro is arranged to be actively adjustable within each revolution of the rotator.

11. The wave power plant as claimed in claim 9, wherein the mass is connected to the rotator shaft with an arm essentially parallel to the axis of rotation of the gyro.

12. The wave power plant as claimed in claim 9, wherein the wheel, the gyro and the generator are connected to rotate together.

13. The wave power plant as claimed in claim 9, wherein the generator load is arranged to be adjusted by a control device which determines the phase lag of the direction of the rotator, that is, the angle between the direction of the rotator and the direction of inclination of the body, and that the set value of the phase lag is adjustable.

14. The wave power plant as claimed in claim 9, wherein the gyro is arranged to be rotated at a speed of rotation which is more than 40 times greater than the speed of rotation of the rotator, and

the speed of rotation of the gyro is arranged to be actively adjustable within each revolution of the rotator.

15. A wave power plant comprising:

a floating body,

a rotator which is supported on the body and rotates around a rotator shaft which is on average vertical or slightly inclined to the side,

a gyro which rotates around a gyro shaft which is on average horizontal, the gyro and the gyro shaft rotating with the rotator around the rotator shaft, and

at least one generator, which is connected to rotate together with the gyro or the rotator, wherein;

the submerged part of the body is a mainly in vertical, or when in operation, the body inclined on average in the incoming direction of the wave, which is transverse to the direction of travel of the waves and the wave extends so deep down that the internal flows of the wave occurring at different heights of the body which cause the body to incline in a direction deviating from the rolling direction according to the direction of the wave surface,

the rotator is located in the upper part of the body and an anchoring point in the lower part of the body to utilize an anchor force for producing a movement of the body,

the rotator comprises a mass, the center of gravity of which is at a distance from the rotator shaft, and an orbital plane of an orbital track of the said center of gravity is at least at said distance from the anchoring point of the body, whereby when the body inclines, the mass generates cophasal torques by the effect of both gravity and the horizontal acceleration of the rotator shaft in order to rotate the rotator,

the gyro is arranged to be used as an equalizer of the said torques during the revolution and as an energy reserve to equalize the effective output of the wave power plant,

when the wave power plant is in operation, the body rolls to and fro with respect to one roll axis, and

the wave power plant further comprises a control device with which the generator load and/or the speed of rotation of the gyro are arranged to be adjusted, and the control device is configured, in the extreme position of inclination of the body, to have the direction of the rotator and gyro shaft at a 0 to 40 degree angle to the roll axis, that is, a set value of the angle between the direction of the rotator and the direction of inclination of the body, that is, of the phase lag, is 90 to 60 degrees.

16. A wave power plant comprising:

a floating body,

a rotator which is supported on the body and rotates around a rotator shaft which is on average vertical or slightly inclined to the side,

a gyro which rotates around a gyro shaft which is on average horizontal, the gyro and the gyro shaft rotating with the rotator around the rotator shaft, and

at least one generator, which is connected to rotate together with the gyro or the rotator,

wherein;

the submerged part of the body is a mainly in vertical, or when in operation, the body inclined on average in the incoming direction of the wave, which is transverse to the direction of travel of the waves and the wave extends so deep down that the internal flows of the wave occurring at different heights of the body which cause the body to incline in a direction deviating from the rolling direction according to the direction of the wave surface,

the rotator is located in the upper part of the body and an anchoring point in the lower part of the body to utilize an anchor force for producing a movement of the body,

the rotator comprises a mass, the center of gravity of which is at a distance from the rotator shaft, and an orbital plane of an orbital track of the said center of gravity is at least at said distance from the anchoring point of the body, whereby when the body inclines, the mass generates cophasal torques by the effect of both gravity and the horizontal acceleration of the rotator shaft in order to rotate the rotator,

the gyro is arranged to be used as an equalizer of the said torques during the revolution and as an energy reserve to equalize the effective output of the wave power plant,

the general shape of the cross-section of the body is a triangle, the shortest leg of which is above water level and one long leg is in the shape of a gently sloping letter S, and

the body tapers downwards and over 80% of the height of the body is below water level when the body is anchored ready for use in calm water.