WO2009065178A1

WO2009065178A1 - Floating sea wave power-generating plant

Info

Publication number: WO2009065178A1
Application number: PCT/AU2008/001726
Authority: WO
Inventors: Xue Feng Ye.
Original assignee: Toprun Ip Australia Pty Ltd
Priority date: 2007-11-22
Filing date: 2008-11-21
Publication date: 2009-05-28
Also published as: CL2008003474A1; CN101169097A; CN101169097B

Abstract

The present invention relates to a floating wave power-generating plant, the plant includes floats suspended on the sea wave, furthermore includes a supporting frame floated on the sea wave with sufficient length, on said supporting frame a long shaft and power generator are mounted, a sprocket wheel assembly is mounted on said lengthened shaft. The floats consist of static float and dynamic float, the static float and dynamic float can be arranged one after another, the static float is fixedly connected with the supporting frame, and on the upper portion of said dynamic float a vertical rod is mounted, which is operatively connected to a sprocket wheel assembly on each short shaft. The short shafts are connected together through shaft couplings to form a long shaft with a length L, and connected to a power generator by means of transmission assembly. The plant has increased stability in all sea states and consistent power output due to the correlation of the length of the shaft with the wave period.

Description

FLOATING SEA WAVE POWER-GENERATING PLANT TECHNICAL FIELD

The present invention relates to power-generating equipment, more particularly a floating sea wave power-generating plant driven by the kinetic energy from sea wave. BACKGROUND OF THE INVENTION

Currently energy sources such as petroleum, natural gas and coal are becoming increasingly short in supply, and in addition environmental pollution is becoming a greater concern. There is an ever increasing focus on the development and utilization of renewable energy sources as a viable and practical alternative to non-renewable energy sources.

There are a great deal of renewable energy sources exist in nature, such as energy of the ocean waves, wind and sun. So far, progress has been made in research of utilization of wind and solar energy, and many power-generating plants using wind energy and solar energy have been established in many countries. As 70 percent of earth area is ocean, a large amount of energy is reserved within the sea wave, it is of great significance to study how to exploit and utilize the wave energy in any sea area for power generation. It is estimated that the useful worldwide resource of wave energy is greater than 2 TW, although some estimates are around 5-10 TW

For power generation by sea wave, some researches have been reported, but the progress is limited .

Wave energy converter (WEC) devices generally fall into one of the following categories:

^• oscillating water column;

^• overtopping devices; • attenuator;

^• point absorbers;

• oscillating wave surge converters; or

^• submerged pressure differential devices. Some examples include the Pelamis, McCabe Wave pump, Archimedes wave swing, Nodding duck and the IPS buoy, each of which have had some limited success but are know to have some shortcomings, especially in areas where the seas are significantly large. The size and strength of ocean waves fluctuate depending on a number of factors, such as wind speed, how long the wind has been blowing, tidal movement and depth of ocean. The resultant waves then can have differing energy potentials that can be difficult to harness if the WEC is not properly designed to withstand the high seas that can form in the open ocean. So far, no economic and efficient wave power-generating device has been found. OBJECT OF THE INVENTION

The objective of the present invention is to provide a floating wave power-generating plant for solving the problem of power generation by the use of wave energy.

It is a further object of the invention to provide a wave power generating plant that is stable in large ocean swells.

It is a further object of the invention to provide a wave power generating plant that provides a continuous power output.

It is an object of the present invention to overcome, or at least substantially ameliorate, the disadvantages and shortcomings of the prior art.

Other objects and advantages of the present invention will become apparent from the following description, taking in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.

SUMMARY OF THE INVENTION The term "wave period" as used herein refers to the time that elapses between successive peaks or troughs of a wave passing a fixed point.

In accordance with the present invention, although this should not be seen as limiting ^■ in any way, a floating wave power-generating plant is provided, said plant includes floats suspended on the sea wave, furthermore includes a supporting frame floated on the sea wave with sufficient length, on said supporting frame a long shaft and power generator are mounted, and a sprocket wheel assembly is mounted on said lengthened shaft, and said supporting frame is held by means of anchor.

Said floats consist of static float and dynamic float, the static float and dynamic float can be arranged one after another and spaced at interval, said static float is fixedly connected with the supporting frame, on the upper portion of said dynamic float a vertical rod is mounted, said vertical rod is provided with a chain, said chain is meshed and connected with the sprocket wheel assembly on short shaft, every dynamic float is respectively connected with the sprocket wheel assembly on every short shaft through the vertical rod, every short shaft is connected together through shaft coupling to form a long shaft with sufficient length, said long shaft is connected with the power generator by means of transmission assembly.

Said sprocket wheel assembly is provided with a ratchet, and the sprocket can be driven to make the long shaft be rotated as a part of dynamic floats move upwards along with the motion of sea wave, thus power can be generated by the power generator, while the sprocket will be made to run idly as said part of dynamic floats move downwards along with sea wave motion.

However, another part of dynamic floats will move upwards again by the action of the wave motion, to drive the sprocket and make the long shaft be rotated, thus power can be continuously and stably generated by the power generator, so as to become a wave power-generating plant.

The wave power-generating plant of the present invention is a power generator floated on the sea wave, which can generate power by harnessing wave energy in any sea area. In the present invention, said supporting frame with sufficient length and for mounting long shaft and power generator can be fixed on a plurality of floats mentioned as static float, to make said frame be floated on the sea wave. Because the frame extends with sufficient length and the static floats have enough quantities, the influence of sea wave motion on the supporting frame is very little. When the supporting frame is held through the anchor, the supporting frame is basically rested on the sea wave, thus a platform of wave power-generating plant can be formed. On such a platform power generator can be installed to generate power, resulting in a wave power-generating plant. When the floating wave power-generating plant of the invention is used, the energy of sea wave can be exploited and utilized to generate power, so as to complement the energy sources with increasing shortage, such as petroleum, natural gas and coal, resulting a contribution to the social development and progress. In further form of the invention there is a floating wave power-generating plant said plant includes floats suspended on a sea wave, the sea wave having a wave period T, a supporting frame floated on the sea wave, at least two dynamic buoys/floats positioned to contact the sea wave and move substantially transverse to the supporting frame, by the action of the sea wave, each dynamic buoy/float includes a vertical rod, on said supporting frame a linear shaft and power generator are mounted, and a sprocket wheel assembly is mounted on said shaft, the vertical rod and sprocket wheel operatively engaged so that reciprocal movement of the vertical rod translates in to rotational movement of the linear shaft, and said supporting frame is held by means of anchor, characterised in that the linear shaft has a length L that is approximately equal to or greater than the wave period or cycle T so as to increase stability of the plant in the ocean.

In preference, the linear shaft includes a plurality of short shaft each connected one to the other

In preference, the frame is open to allow the sea wave to pass through. In preference, the dynamic floats are housed or contained in modular units to allow for straightforward changes to the plant as a whole to be made, such as making the overall plant longer or shorter dependant upon the wave period, or average wave period, of the seas that it is positioned.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is the structural diagram of a floating wave power-generating plant in the present invention.

Figure 2 is the enlarged structural diagram of wave power-generating plant in Figure 1 that is equipped with three dynamic floats.

Figure 3 shows the wave power-generating plant in a body of water, with the dynamic floats at varying positions. ^ DETAILED DESCRIPTION OF THE INVENTION

Referring to Figure 1, a floating wave power-generating plant of the present invention, said plant includes floats suspended on the sea wave, furthermore includes a supporting frame 9 floated on the sea wave with sufficient length, on said supporting frame 9 a long shaft 10 and power generator 1 are mounted, and a sprocket wheel assembly 7 is mounted on said long shaft 10, and said supporting frame 9 is held by means of anchor.

The supporting frame is manufactured in an open manner, such as from a scaffold material or similar so to allow water and air to flow through it. Said floats consist of a plurality of static floats 8 and dynamic floats 6, the static float 8 and dynamic float 6 can be arranged one after another and spaced at interval. For example, as shown in Figure 1, one static float 8 is arranged to space at interval with every three dynamic floats 6 that compose as a whole. Moreover, said static float 8 is fixedly connected with the supporting frame 9, namely said supporting frame 9 for mounting the power generator 1 is installed on a plurality of static floats 8, said supporting frame 9 can be floated on the sea wave by means of buoyant force of the static floats 8. The number of static floats 8 and dynamic floats 6 can be set as several tens, even several hundreds.

Said dynamic floats 6 are floated on the sea wave, and said dynamic floats move upwards and downwards along with the wave under influence of sea wave. On the upper portion of said dynamic float 6 a vertical rod 61 is mounted, said vertical rod 61 is provided with a chain, said chain is meshed and connected with sprocket wheel assembly 7 mounted on short shaft 4. Every said dynamic float 6 is respectively connected with each sprocket wheel assembly 7 on short shaft 4 through said vertical rod 61 , namely one sprocket wheel assembly 7 is connected with one dynamic float 6.

Every short shaft 4 is arranged in a bearing seat 3, said bearing seat 3 is mounted on the supporting frame 9. Each of short shafts is connected together through a shaft coupling 5 to form a long shaft 10. Said long shaft 10 is connected with power generator 1 by means of transmission assembly 2, and the rotating speed of said long shaft 10 can be converted into the rotating speed required by the power generator by means of transmission assembly 2. Said sprocket wheel assembly 7 is provided with a ratchet, the sprocket can be driven to make the long shaft 10 be rotated and cause the power generator 1 to generate power as a part of dynamic floats 6 move upwards along with wave motion, and the chain on said vertical rod 61 is driven to move upwards together; while the sprocket will be made to run idly as said part of dynamic floats 6 move downwards along with wave motion under influence of ratchet. However, another part of dynamic floats 6 will move upwards again by the action of wave motion, to drive the sprocket and make the long shaft 10 be rotated. Because there are always dynamic floats 6 that move upwards along with wave motion to drive the long shaft 10 be rotated at any time, therefore the power can be continuously and stably generated by the power generator 15 so as to become a wave power-generating plant.

Referring to Figure 2, three dynamic floats 6 can be composed as a group, and on every dynamic float 6 a roller 62 is mounted, and a guideway can be fixedly mounted on the supporting frame 9, said roller 62 rolls in the guideway, thus said dynamic floats can be caused to move upwards and downwards in a straight line along the guideway, which ensures the accuracy of engagement between the chain on the vertical rod 61 and the sprocket on the sprocket wheel assembly 7, thus to drive the long shaft 10 to be rotated.

The long shaft 10 in combination with the short shafts 4 have an overall length L, and this length can be altered by removing or adding on additional units, each of which have their own dynamic float.

Each dynamic float is housed in a separate modular unit, so in this manner it is easy for the plant as a whole to be lengthened or shorted so that an array can be readily constructed depending on the size of the seas to which the plant is to be positioned. In addition, the modularity of the units makes it easy to perform maintenance as units can be readily removed and added as required.

Waves have a period, or length, T, which is the length as measured between the crests, or troughs, of two adjacent waves. If the overall length L of the shafts is less than the wave period T then the floating wave power-generating plant will be unstable and some of the buoys will not be efficient in turning the shaft as they will not move significantly. This will result in sporadic rotation of the long shafts 10 and thus the power output of the plant will be reduced and the stability of the plant is compromised, which can result in it capsizing.

As seen in Figure 3, the wave moves the dynamic floats ^β to varying positions making the shaft 10 rotate in a consistent manner. Importantly, the present invention fixes this issue by having ensuring that L is equal to or greater than the wave period T, so that the buoys/floats that first contact the wave front will move upwards and as the wave moves along the length of the plant each buoy will rise and fall in succession, without decreasing the stability of the plant.

Due to the stability of the plant from having L ≥ T, then it is not required that the plant have over engineered moorings.

As the frame has an open construction that presents a greatly reduced surface area to the wave, the surging wave can pass through the frame, without greatly contributing to the destabilisation of the plant

In fact the resultant increased in stability removes the need for the plant to be actively anchored to the sea floor and can be restrained using more convenient and economical methods that have a lesser impact on the environment.

Furthermore, as the plant has increased stability and the movement of the buoys is more regular this then removes the need for the plant to have a flywheel connected to the long shaft l O.Accordingly, for the common skilled technician in the art, it is to be understood that the said embodiments have been described only for the present invention and not for purposes of limitation on the present invention. Within the actual spirit and scope of the invention, any variation for the embodiment in the form and details that will be subject to the range of the invention claims. Therefore, the invention is limited only by the appended claims.

Claims

1. A floating wave power-generating plant said plant includes: a. a plurality of static floats suspended on a sea wave, the sea wave having a wave period T, b. a supporting frame," connected to the static floats, floated on the sea wave, c. at least two dynamic floats positioned to contact the sea wave and move substantially transverse to the supporting frame, by the action of the sea wave, d. each dynamic float includes a vertical rod, e. on said supporting frame a linear shaft and power generator are mounted, and a sprocket wheel assembly is mounted on said shaft, the vertical rod and sprocket wheel operatively engaged so that reciprocal movement of the vertical rod translates into rotational movement of the linear shaft, and f. characterised in that the linear shaft has a length L that is approximately equal to or greater than the wave period T so as to increase stability of the plant on the sea wave.

2. The floating wave power-generating plant of claim 1 , further characterised in that the frame is open so as to present reduced surface area to the sea wave, to allow the sea wave to pass there though.

3. The floating wave power-generating plant of claim 2, further characterised in that the dynamic floats are posited within a set of guiderails secured to the supporting frame.

4. The floating wave power-generating plant of claim 3, further characterised in that the dynamic floats have at least two guide wheels located thereon, each guide wheel located within a corresponding guiderail to facilitate consistent tracking of the dynamic float.

5. The floating wave power-generating plant of claim 4, further characterised in that said supporting frame is held by means of an anchor.

6. The floating wave power-generating plant of claim 5, further characterised in that the dynamic floats are housed within modular units.