AU2007221820B2

AU2007221820B2 - Ocean wave swell energy converter

Info

Publication number: AU2007221820B2
Application number: AU2007221820A
Authority: AU
Inventors: Bernard Arthur Packer
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-10-05
Filing date: 2007-10-03
Publication date: 2011-09-08
Anticipated expiration: 2027-10-03
Also published as: AU2007221820A1

Abstract

-21 A mechanism for extracting energy from the velocity and mass of water in an ocean swell; said method including a swell intercepting structure; said structure including a reactive 5 body at least partially immersed in said swell; said reactive body mechanically linked to an hydraulic~ system wherein movement of said reactive body is translated into hydraulic pressure; and wherein a lever system pivots about an axis in response to said swell; said lever system transmitting linear 10 lateral motion to a common slide bar connected to respective piston rods of an array of hydraulic rams; angular displacement of said lever system transferred to said linear lateral motion by means of wire rope connecting said lever system to said common slide bar. 77 77 Vt - - _ 9 7 7 - - - - IN Fr.4 - I yr

Description

P/00/009 Regulation 3 10 5 AUSTRALIA Patents Act 1990 10 COMPLETE SPECIFICATION 15 Invention Title: 20 OCEAN WAVE SWELL ENERGY CONVERTER 25 The invention is described in the following statement, including the best method of performing it known to us: 30 35 40 45 Our Ref: 072035 50 -2.

OCEAN WAVE SWELL ENERGY CONVERTER The present invention relates to a method of extracting useful energy from the transverse swell motion of bodies of 5 coastal water. BACKGROUND The search for sources of energy other than from fossil fuels has become increasingly important in recent years. Among the so-called renewable energy sources, it has long been 10 recognized that the movement of water both as tidal and as waves along coastlines, has the potential to provide a significant energy contribution. While the number of experimental and small pilot schemes continues to increase, problems with the extraction of energy 15 continue to revolve around the efficiency and durability of installations. It is an object of the present invention to provide an improved method of wave energy extraction, or at least provide a useful alternative. 20 BRIEF DESCRIPTION OF INVENTION Accordingly, in a first broad form of the invention, there is provided a mechanism for extracting energy from the velocity and mass of water in an ocean swell; said method including a swell 25 intercepting structure; said structure including a reactive body at least partially immersed in said swell; said reactive body -3 mechanically linked to an hydraulic system wherein movement of said reactive body is translated into hydraulic pressure; and wherein a lever system pivots about an axis in response to said swell; said lever system transmitting linear lateral motion to 5 a common slide bar connected to respective piston rods of an array of hydraulic rams; angular displacement of said lever system transferred to said linear lateral motion by means of wire rope connecting said lever system to said common slide bar. Preferably, said array of hydraulic rams provide hydraulic fluid 10 pressure for driving power generating equipment. Preferably, said reactive body comprises an assembly of a pair of spaced apart main levers and a float; said float supported between said pair of main levers to form a main levers and float assembly. 15 Preferably, each of said pair of main levers is attached at a first upper end to a freely rotating axle; said float supported at a second lower end of said main lever. Preferably, said axle is supported horizontally at a level above said ocean swell and transverse to the direction of said swell; 20 said main levers and said float sized so as to present said float to the root of said swell. Preferably, said main levers and said float are suspended from said axle such that said main levers and said float are in an angled position towards the direction of an approaching swell -4 when said main levers and float assembly is positioned at a beginning of a power stroke. Preferably, said main levers and float assembly is further provided with counter weights; said counter weights arranged to 5 return said main levers and float assembly to said angled position at said beginning of said power stroke. Preferably, said counter weights are a pair of counterweights; each of said pair attached to a counterweight lever attached to a respective said main lever; said counterweight lever depending 10 vertically from below said axle. Preferably, a shorter lever is attached to each said upper end of said pair of main levers; respective longitudinal axes of each said shorter lever and respective said main lever intersecting substantially at the axis of said axle; said 15 shorter lever and said main lever forming an obtuse angle between them such that at said beginning of a power stroke, said shorter lever is angled in the direction opposite a said approaching swell. Preferably, a shorter-lever bar extends between outer ends of 20 said shorter levers. Preferably, an array of said hydraulic rams is arranged with rams disposed side by side; said array extending between said pair of main levers.

-5 Preferably, each piston rod of each of said hydraulic rams is attached to a common slide bar; each said piston rod being in a maximum extended position when said main lever and float assembly is at said beginning of a power stroke. 5 Preferably, substantially horizontal passage of a body of water of a said swell through said swell intercepting structure causes angular displacement of said main lever and float assembly about said axle; said displacement urging a corresponding angular displacement of said shorter levers and said shorter-lever bar. 10 Preferably, said angular displacement of said shorter-lever bar due to flow of a said swell is translated into linear lateral movement of said common slide bar; said movement acting tb -drive piston rods of said array of hydraulic rams from said maximum extended position to a retracted position, thereby to cause a 15 flow of hydraulic fluid under pressure to issue from said rams. Preferably, said hydraulic fluid under pressure is directed to drive electrical power generating equipment. Preferably, said angular displacement and said movement of said common slide bar is concurrent with a said swell passing by said 20 swell intercepting structure; said angular displacement reversing after passage of a said swell to return said main levers and float assembly and said rams to said position at a beginning of a power stroke.

-6 Preferably, said shorter-lever bar and said common slide bar are interconnected by a wire rope; said wire rope passing around a pair of main sheaves or pulleys and supported by an array of sheaves supported on a generally semi-circular structure; said 5 semi circular structure overarching said axle. Preferably, said main levers and float assembly, said axle, said array of hydraulic rams, said shorter-lever bar, said common slide bar are supported within a carriage; said carriage supported within an array of vertical supporting piles. 10 Preferably, said carriage is adapted for vertical displacement relative said piles; said vertical displacement arranged to allow adjustment of said immersion of said reactive body. Preferably, said float is slidingly attached between said pair of main levers; said main levers incorporating hydraulic rams 15 whereby said float can be raised or lowered relative said main levers, In another broad form of the invention there is provided a mechanism for extracting kinetic energy from substantially horizontally moving bodies of water in ocean swells; said 20 mechanism including a swell intercepting structure at least partially immersed in said swell; said structure pivotally supported so as to be displaced angularly with passage of a said swell; said angular displacement transmitted as linear motion to an hydraulic system by means of a wire rope interconnecting a -7 pivoting lever system of said structure with a common slide bar; said common slide bar connecting respective piston rods of an array of hydraulic rams. BRIEF DESCRIPTION OF DRAWINGS 5 Embodiments of the present invention will now be described with reference to the accompanying drawings wherein: Figure 1 is a schematic representation of a reactive body interacting with substantially horizontally displaced bodies of water of ocean swell, 10 Figure 2 is a side view of an ocean swell energy converter according to a preferred embodiment of the invention, Figure 3 is a plan view of selected active components of the converter of Figure 2. 15 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS With reference to Figure 1, the principle of the present invention resides in the utilization of the velocity and mass of substantially horizontally translated bodies of ocean water due to the swell 10 approaching a shore (not shown) A power 20 generating installation as described hereunder may be located at suitable positions along a shore line to take advantage of the kinetic energy contained in these bodies of moving water. With reference also to Figure 2, a lever and float assembly 12 is arranged in a power generating installation 14 so that the lower end 16 of the assembly is at least partially immersed in the swell 10 with the lowermost end 14 extending at least to below the "root" or trough of the swell. To this end, as will be described below, the lever and float assembly 12 is supported on 5 a carriage structure which may be adjusted for height. Again with reference to Figure 1, it can be seen that the lever and float assembly is arranged to pivot about a horizontal axle 18 supported above the ocean swell and transverse to the direction of the swell. During a power stroke, lever and float 10 assembly 12 swings from a position "A" at the beginning of the power stroke, to a maximum deflected position "B" at the end of a power stroke, the assembly then swinging back to position "A" for a following power stroke. Preferably, the device is adapted for use in swells "S" of between one and a half and two metres. 15 With reference now to Figures 2 and 3, lever and float assembly 12 comprises a pair of spaced apart main levers 20 and 21 (not shown in Figure 3 for clarity) pivoting about a freely rotating axlel8. A suitable float 22, for example made up of an assembly of stainless steel drums (not shown) is supported between the 20 pair of main levers 20 and 21. The main lever and float assembly 12 is shown in Figure 2 in the position at the beginning of a power stroke so that the swell (not shown in Figure 2) progresses from left to right. Attached to the first upper end of each of main levers 20 and 21 25 are shorter levers 24 and 25 rigidly affixed the main levers. The arrangement is such that the longitudinal axes of each -9 respective main lever 20 and shorter lever 24, and main lever 21 and shorter lever 25 respectively, subtend an obtuse angle at the axis of axle 18, with the shorter levers pointing in the direction of the swell movement when the lever and float 5 assembly 12 is in the position at the beginning of a power stroke. A shorter-lever bar 26 extends between the outer ends of shorter levers 24 and 25. Strengthening supports 28 are provided at intermediate positions along shorter-lever bar 26 between the 10 bar and axle 18. It will be understood that, as the lever and float assembly 12 is rotationally displaced due to a passing swell, the shorter levers 24/25 and therefore the shorter-lever bar 26 sweep out an arc centred on the axis of axle 18. AtLached to, or adjacent to each of main levers 20 and 21, and 15 depending vertically from below axle 18, are counterweight levers 28 and 29 (Figure 2) suspending counterweights 30 and 31. As the lever and float assembly moves through its arc under the influence of passing swell, the counterweights swing upwardly, providing potential energy to return the lever and float 20 assembly 12 to its position to begin another power stroke. Also arranged between main levers 20 and 21 is an array of hydraulic rams 34 arranged side by side. The outer end of the piston rod 36 of each ram 34 is connected to a common slide bar 38 arranged so that the rams 34 may be activated in unison. 25 An overarching semicircular structure 40, preferably arranged at a mid point between main levers 20 and 21 and centred on the - 10 axis of axle 18, provides support for an array of sheaves 42. A loop of wire rope 44 extends over sheaves 42 and around main sheaves 43 and 45, and is connected to common slide bar 38. The radius of the semi-circular arc defined by sheaves 42 is such 5 that the shorter-lever bar 26 may also be connected to the wire rope 44 with the shorter-lever bar 26 just clearing the sheaves as it sweeps out the arc due to swell movement. This movement of the shorter-lever bar 26 drives the loop of wire rope 44 Lhrough and around the sheaves and hence drives the common slide bar 38, 10 driving the ram piston rods 36 from their initially extended position as shown in Figures 2 and 3 to a retracted position. Hydraulic fluid in the rams 34 is thus pressurised by movement of pistons 37 and may be used to drive electric generating equipment, either located within the power generating 15 installation 14 (not shown) or piped to on-shore power generating equipment. Hydraulic flow and pressure may be controlled by a non-return control valve assembly 50. For maintenance purposes or in case of excessively rough Sea conditions, reverse hydraulic rams 52 may be provided to drive 20 the lever and float assembly 12 clear of the water at the end of a power stroke. In a preferred alternative arrangement, the main levers of the lever and float assembly 12 may be provided wiLh hydraulic rams and suitable guides (not shown), by means of which the float can be retracted clear of the water level. 25 As shown in Figures 2 to 4, the active components of the power generating installation, that is the lever and float assembly - 11 12, hydraulic rams 24 and their activating components are supported in a carriage 54 comprising a robust framework and slidingly supported within a permanent array of vertical piles 56. Vertically operating hydraulic rams 57 are arranged to 5 adjust the height of carriage 54 relative the piles 56 and thus also relative to the level of swell passing through the installation 14. Telescopic stabilising units 58 and interconnecting lifting plates 60 ensure proper conLrol of the lifting and lowering of the carriage 54. This arrangement also 10 allows for the assembly of the carriage and its components to be raised above sea level for maintenance purposes if required. Figure 2 shows the carriage in the raised position with the lifting rams 58 extended. 15 SUMtaRY A robust carriage is assembled constrained by piles and capable of being moved up and down within the piles per medium of hydraulics or winch and hoist assembly. 20 Across the width of said carriage is an axle from which is suspended a reinforced float and lever assembly of a length and angle to suit the conditions. To this lever there is attached aL an angle a shorter lever of a length to give the desired mechanical advantage. Suspended directly under the axle buL 25 attached to the long lever and float assembly is a further lever to which is attached a counter weight that will ensure that - 12 the float and lever assembly always returns to the desired position ready to be activated by the next incoming swell/wave, Over arching the axle is a half circle assembly which acts as 5 support for sheaves required to support wire rope cable that is being moved by shorter lever thus activating hydraulic rams per medium of sheaves so placed as to facilitate same. Due to a bar the width of the unit being attached to the end of 10 the shorter lever and a slide bar used to activate hydraulic rams a predetermined no of rams can be set up across the width of the unit. The return of the float and lever assembly ready to be reactivated re-feeds hydraulic fluid to the rams. The non return valve assembly is placed at the pressure end of the rams 15 to control feed and pressure flow to common hydrauli c accumulator. As an alternative to raising and lowering the carriage the main levers have hydraulic cylinders on either side of the levers 20 that enable the float unit to be raised and lowered when and if necessary. Also reverse ram cylinders can be operated from the normal operating configuration which operate on a free flow of hydraulic fluid. A stop valve/s between the ram and reservoir enables the float and lever assembly to be stopped at the 25 completion of the stroke.

- 13 An object of the invention is to utilize the speed and mass of water contained in an ocean swell / wave to produce volume of Hydraulic fluid at a pressure that enables industrial use, particularly in the production of electricity. Piles are driven 5 into the ocean bed to enclose a predetermined area of ocean shoreline in the area prior to the wave break thus accessing the swell energy in the following manner. Towards or at the top of the piles, suitable fabrication is put 10 in place to constrain and support a robust carriage that has the ability to be raised or lowered per medium of hydraulics or winch and hoist. Across the width of the said carriage is a free moving axle which has aL either end an activating lever of suitable length and angle to 15 ensure that a float of suitable design, set up between said levers, can be presented to the root of the swell that is following the breaking wave thus moving the float and lever assembly towards the wave break area at speed. 20 To the main activating levers is attached a shorter lever at an angle and of a length to give the desired mechanical advantage and movement required to operate hydraulic rams. Suspended directly under the axle but attached to each 25 activating lever of the lever and float assembly, is a furLher lever to which is attached a counter weight that will ensure - 14 that float and lever assembly always returns to the desired position ready to be activated by the next incoming swell/wave. 5 To obtain the maximum movement of the hydraulic rams plungers a semi-circular assembly to support sheaves is positioned over arching the axle and central to the main activating levers; the dimension of same to be of direct relation to the length of shorter levers to attached to the main activating levers. A reinforced bar across the width of the carriage from shorter lever to shorter lever that just clears the sheaves on the semi circular support assembly, enables wire rope which is affixed to 15 the shorter lever bar to be relieved from and reengaged with Lho sheaves to be utilised to move a re-inforced slide bar that is connected to hydraulic cylinder plunger rods. Master sheaves positioned under shorter lever bar and prior to ram rod activating bar facilitates this. 20 Maximum movement of the hydraulic ram's plungers is obtained by the releaving and reengaging of the wire rope to the sheaves on the semi circular assembly by the bar on the shorter levers when motion is initiated by movement of main 25 activating levers by the swell. Non return valves incorporated - 15 with the ram cylinders will control pressure flow and recharging of fluid from the reservoir to the hydraulic ran cylinders. To ensure there is facility to disengage the float and active 5 lever assembly from the wave action reverse hydraulic cylinders are positioned at the rear of the slide bar operating with free movement of fluid from reservoir to hydraulic cylinders but with shut off valves positioned to stop the fluid movement thus enabling the active lever and float to be stopped at the 10 completion of a stroke for maintenance and/or violent sea conditions. To ensure that full pressure potential can be used to maintain pre-determined pressure 15 and flow rate, delivery from the Hydraulic rams is directed to a combination manifold pressure vessel that has a safety pressure release above that of the flow rate and pressure to be utilised. The units are situation flexible in that engineering decisions can be made to utilise the hydraulic energy on the 20 unit to power generators on site or to pipe same to land based common accumulator.

Claims

1. A mechanism for extracting energy from the velocity and mass of water in an ocean swell; said method including a swell intercepting structure; said structure including a reactive 5 body at least partially immersed in said swell; said reactive body mechanically linked to an hydraulic system wherein movement of said reactive body is translated into hydraulic pressure; and wherein a lever system pivots about an axis in response to said swell; said lever system transmitting linear 10 lateral motion to a common slide bar connected to respective piston rods of an array of hydraulic rams; angular displacement of said lever system transferred to said linear lateral motion by means of wire rope connecting said lever system to said common slide bar, 15

2. The mechanism of claim 1 wherein said array of hydraulic rams provide hydraulic fluid pressure for driving power generating equipment.

3. The mechanism of claim 1 or 2 wherein said reactive body comprises an assembly of a pair of spaced apart main levers 20 and a float; said float supported between said pair of main levers to form a main levers and float assembly.

4. The mechanism of claim 3 wherein each of said pair of main levers is attached at a first upper end to a freely rotating -17 axle; said float supported at a second lower end of said main levers.

5. The mechanism of claim 4 wherein said axle is supported horizontally at a level above said ocean swell and transverse 5 to the direction of said swell; said main levers and said float sized so as to present said float to the root of said swell,

6. The mechanism 6f claim 4 or 5 wherein said main levers and said float are suspended from said axle such that said main 10 levers and said float are in an angled position towards the direction of an approaching swell when said main levers and float assembly is positioned at a beginning of a power stroke.

7. The mechanism of any one of claims 3 to 6 wherein said main 15 levers and float assembly is further provided with counter weights; said counter weights arranged to return said main levers and float .assembly to said angled position at said beginning of said power stroke.

8. The mechanism of claim 7 wherein said counter weights are a 20 pair of counterweight; each of said pair attached to a counterweight lever attached to a respective said main lever; said counterweight lever depending vertically from below said axle. -18

9. The mechanism of claim 6, 7 or a wherein a shorter lever is attached to each said upper end of said pair of main levers; respective longitudinal axes of each said shorter lever and respective said main lever intersecting substantially at the 5 axis of said axle; said shorter lever and said main lever forming an obtuse angle between them such that at said beginning of a power stroke, said shorter lever is angled in the direction opposite a said approaching swell.

10. The mechanism of claim 9 wherein a shorter-lever bar extends 10 between outer ends of said shorter levers.

11. The mechanism of any one of claims 3 to 10 wherein an array of said hydraulic rams is arranged with rams disposed side by side; said array extending between said pair of main levers.

12. The mechanism of claim 11 wherein each piston rod of each of 15 said hydraulic rams is attached to a common slide bar; each said piston rod being in a maximum extended position when said main lever and float assembly is at said beginning of a power stroke.

13. The mechanism of claim 10, 11 or 12 wherein substantially 20 horizontal passage of a body of water of a said swell through said swell intercepting structure causes angular displacement of said main lever and float assembly about said axle; said displacement urging a corresponding angular displacement of said shorter levers and said shorter-lever bar, -19

14. The mechanism of claim 13 wherein said angular displacement of said shorter-lever bar due to flow of a said swell is translated into linear lateral movement of said common slide bar; said movement acting to drive piston rods of said array 5 of hydraulic rams from said maximum extended position to a retracted position, thereby to cause a flow of hydraulic fluid under pressure to issue from said rams.

15. The mechanism of claim 14 wherein said hydraulic fluid under pressure is directed to drive electrical power generating 10 equipment.

16. The mechanism of claim 13, 14 or 15 wherein said angular displacement and said movement of said common slide bar is concurrent with a said swell passing by said swell intercepting structure; said angular displacement reversing 15 - after passage of a said swell to return said main levers and float assembly and said rams to said position at a beginning of a power stroke.

17. The mechanism of any one of claims 12 to 16 wherein said shorter-lever bar and said common slide bar are 20 interconnected by a wire rope; said wire rope passing around a pair of main sheaves or pulleys and supported by an array of sheaves supported on a generally semi-circular structure; said semi circular structure overarching said axle. -20

18. The mechanism of any one of claims 12 to 17 wherein said main levers and float assembly, said axle, said array of hydraulic rams, said shorter-lever bar, said common slide bar are supported within a carriage; said carriage supported within 5 an array of vertical supporting piles.

19. The mechanism of claim 18 wherein said carriage is adapted for vertical displacement relative said piles; said vertical displacement arranged to allow adjustment of said immersion of said reactive body. 10

20. The mechanism of any one of claims 3 to 19 wherein said float is slidingly attached between said pair of main levers; said main levers incorporating hydraulic rams whereby said float can be raised or lowered relative said main levers.

21. A mechanism for extracting kinetic energy from substantially 15 horizontally -moving bodies of water in ocean swells; said mechanism including a swell intercepting structure at least partially immersed in said swell; said structure pivotally supported so as to be displaced angularly with passage of a said swell; said angular displacement transmitted as linear 20 motion to an hydraulic system by means of a wire rope interconnecting a pivoting lever system of said structure with a common slide bar; said common slide bar connecting respective piston rods of an array of hydraulic rams.