GB2461306A

GB2461306A - Paddle driven wave energy converter

Info

Publication number: GB2461306A
Application number: GB0811778A
Authority: GB
Inventors: Allen Charles Peter Cox
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-06-27
Filing date: 2008-06-27
Publication date: 2009-12-30
Anticipated expiration: 2028-06-27
Also published as: GB0811778D0; GB2461306B

Abstract

A wave energy converter has a hinged paddle 31 attached below a reciprocating pump 1 on a floating vessel 5. The pump 1 is carried by a frame 2 which is attached to the side of a vessel 5. The paddle is driven by the waves, and is connected to the pistons 7, 8 in pump cylinders 9, 10. The entire hydraulic system comprising tank 11 and turbine 17 may be attached to the frame. There may be a balance weight 35 to balance movement of the paddle 31. The pump and its accessories carried by the frame 2 together with the paddle 31 can be bodily raised and lowered, for example by a jib crane, for adjusting their height on the vessel to obtain maximum orbital energy from the passing waves. A number of the pumps 1 may be located in one or more rows on one or both sides of the vessel.

Description

GENERATING POWER FROM WAVES

At this time of Climate Change and Global Warming the practice of obtaining energy from carbon fuels is now considered to be against the present principle of reducing carbon dioxide in the Earth's atmosphere. A partial solution to this problem is to use wave power. Waves are generated by the wind, a wind speed of as low as 2 mph can make waves.

The energy in waves is called Orbital Energy. As a wave moves forwards, a particle in the crest of a wave moves forwards then downwards, then it moves backwards and finally upwards, so that although a wave appears to move towards the shore in reality a particle, or even a parcel of water, moves up and down It is towards the use of this abundant and almost continuous supply of energy that the present invention is directed.

According to the invention there is provided a method of generating electricity by wave power in which a floating support on wave-generating water carries a reciprocating pump operatively connected to an electricity generator and a paddle which is hinged to be movable upwards and downwards relative to the floating support under the action of waves generated on the water and which paddle is connected to a piston or cylinder of the pump to cause operating movement between the piston and cylinder whereby the electricity generator is driven.

The invention also provides a reciprocating pump and paddle, adapted for use in this method.

The floating support may be of any suitable kind, such as, for example, a floating vessel, sail or motor powered, a raft, platform or pontoon. The pump and paddle may be located on a side of a vessel or possibly an outrigger on the vessel.

The vessel or other floating support may be situated at any appropriate location where waves are generated on the water sufficient to provide the upwards and downwards movement of the paddle necessary to operate the pump.

The pump may be held in a frame or casing carried by the floating support.

Either one of the piston and cylinder of the pump may be fixed with respect to the frame or casing and the other connected to the paddle for movement thereby relative to the frame of casing. Whichever of the piston and cylinder is movable relative to the frame or casing may have a crosshead which is coupled to the paddle by a connecting rod or rods and is engaged with a guide or guides on the frame or casing to guide the piston or cylinder in its movement relative to the frame or casing.

Preferably the pump is supported by the floating support above the waterline of the support and the paddle is hingedly supported below the pump.

Conveniently the pump and paddle, and the frame or casing when provided, are mounted on a carrier which is attached to the floating support. The carrier my be adjustable on the floating support so as to adjust the height of the paddle on the support relative to the waves generated on the water and thereby vary the extent of the hinged movement of the paddle under the action of the waves. Alternatively, or possibly in addition, the paddle may be adjustable on the carrier for the same purpose.

It is desirable for the paddle to be positioned at a height to enable the maximum use to be made of the available orbital energy in the waves for operating the pump.

For adjustment of the carrier, the carrier may comprise a backplate which is attached to the floating support using guides which enable the backplate to be moved upwards and downwards on the support to vary the height of the paddle as necessary.

The floating support may include a jib crane by which the paddle and/or the frame or casing may be hoisted and lowered to adjust their position with respect to the floating support.

The electricity generator may be mounted on or in the frame or casing. A reservoir for fluid for the pump and a turbine through which the fluid is circulated by the pump to drive the electricity generator may also be mounted on or in the frame or casing.

A balance weight may be provided in combination with the paddle to counter the weight of the paddle and associated equipment which may have a detrimental effect of reducing orbital energy available at the pump from the action of waves generated on the water.

The reciprocating pump may be used in conjunction with one or more other similar reciprocating pumps carried by the floating support each operatively connected to an or the electricity generator and to a or the hinged paddle movable upwards and downwards relative to the floating support under the action of waves generated on the water, thereby to cause operating movement between the piston and cylinder of the pump whereby the, or the respective, electricity generator is driven.

The pumps may be supported on the floating support at opposite sides of the support.

Using two or more pumps each moving wave with its orbital energy may operate the paddle of each pump in turn as it passes along sides of the support.

The or each paddle may be of a plate-like form and have a flat or profiled upper and/or lower surface as appropriate to facilitate as much as possible the movement of the paddle under the action of waves.

The or each reciprocating pump may have more than one cylinder and/or piston between which the operating movement is caused by the paddle.

Since the number of working parts of the complete assembly used in the method may be few, and particularly when, as preferred, the or each pump is supported above the waterline of the support, maintenance may be carried out without undue difficulty and should not be required very frequently. However, work on parts of the or each assembly may be facilitated in situ by arranging a cat walk or cat walks suitably supported by the floating support alongside the assembly or assemblies.

An embodiment of this invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 is a side view of a reciprocating pump and associated apparatus according to the invention; Figure 2 is a plan view of an upper cylinder of the pump and inlet and outlet manifolds of that cylinder; Figure 3 is a plan view of a mounting bracket of the pump; Figure 4 is a plan view of a crosshead included in the pump; Figure 5 is a plan view of a paddle connected to the pump; Figure 6 is a side view of a vessel on which the pump and several other similar pumps are provided for use to be operated by wave power, and Figures 7 to 10 are enlarged fragmentary views of manifolds and non-return valves of the pump.

Referring to Figures 1 and 6, a reciprocating pump 1 is held in a frame 2 carried by an upright, vertically elongated backplate 3 mounted on the exterior of a side 4 of the hull of a vessel 5 anchored on a body of wave-generating water. The backplate 3 is adjustable, by a jib crane not shown, on substantially vertically extending guide rails 6 fixed to the hull side 4 so that the height at which the backplate 3, also seen in Figure 5, is located can be adjusted.

The reciprocating pump I comprises co-axial upper and lower pistons 7 and 8 which operate respectively in upper and lower cylinders 9 and 10. Pump oil is circulated to the cylinders 9, 10 from a reservoir tank 11 mounted on the frame 2 above the level of the pump. The oil is charged into the upper cylinder 9 from the reservoir tank through an upper inlet manifold 12 and an upper inlet non-return valve 13 at the manifold. The upper piston 7 drives the charged oil out of the cylinder through an upper outlet manifold 14 having an upper outlet non-return valve 15 to prevent back-flow of the oil to the cylinder through that manifold. Oil driven from the upper cylinder 9 is directed through an upper feed pipe 16 to a turbo-electric generator 17, also carried by the frame above the pump, before being returned to the reservoir tank 11. The upper cylinder 9 and its inlet and outlet manifolds 12, 14 can be seen in Figures 1 and 2. The lower cylinder 10 receives oil from the reservoir tank 11 by way of a supply pipe 18 and through a lower inlet manifold 19 and lower inlet non-return valve 20. The lower piston 8 drives the charged oil out of the lower cylinder 10 through a lower outlet manifold 21, also having a lower outlet non-return valve 22 to prevent back-flow of the oil from that outlet to the lower cylinder, and into a lower feed pipe 23 connected to the upper feed pipe 16 to take the oil to the generator 17 before returning to the reservoir tank 11.

A by-pass pipe 24 extends between the upper feed pipe 16 and the reservoir tank 11 through which, by operation of stop valves 25 at those two pipes, oil driven from the upper and lower cylinders can be returned straight back to the reservoir instead of through the generator 17 if for any reason operation of the generator is not required while the pump continues to be operative.

The upper and lower cylinders 9, 10, their inlet and outlet manifolds and the upper and lower feed pipes 16, 23 are all fixed relative to the frame 2. Two brackets 26 of the frame 2 by which the frame is fixed to the backplate 3 are of plate form, as shown in Figure 3, and each has a through aperture 27 in which a respective one of the upper and lower cylinders 9, 10 is fixed.

The upper and lower pistons 7, 8 are fixed to, respectively above and below and centrally of, a horizontal cross-head 28, Figures 1 and 4, of square-shaped plate form, slidingly engaged at two diagonally opposite corners with guide bars 29 included in the frame for upwards and downwards movement of the cross-head, and thereby of the pistons, relative to the frame. At its two other diagonally opposite corners the cross-head 28 has attached to it upper ends of a pair of connecting rods 30 which are swivally attached at their lower ends to opposite longer sides of a generally rectangular paddle 31, Figures 1 and 5, also of a plate form, directly below the pump 1 and frame 2. The paddle 31 is hinged at one end about a horizontal pivot 32 to the lower part of the backplate 3 so that the paddle is able to swing upwards and downwards relative to the backplate about the pivot. As the paddle 31 swings upwards and downwards the connecting rods 30, and hence the cross-head 28, move upwards and downwards with it so that the pistons 7, 8 are operatively moved in the cylinders.

The backplate 3 is adjusted on the hull side 4 of the vessel 5 to a height such that the paddle 31 is positioned to receive optimum hinged movement from the action of waves generated on the water on which the vessel is floating. The aim is to enable maximum use to the made of the available orbital energy in the waves to operate the pump. The backplate supports the pump above the waterline of the vessel.

Upper and lower surfaces of the paddle 31 may be flat, as shown, or they may be profiled to a form which may enhance further the movement of the paddle under the influence of the available wave motion.

Attached at lower ends to the cross-head 28, in line with the connecting rods are two further connecting rods 33 which extend upwards in the frame 2 to a level above the generator where they are pivotally attached to one end of an arm 34 carrying a balance weight 35 at its other end, away from the hull side 4. The arm 34 is carried by the frame on a pivot 36 which allows the arm to rock up and down with the motion of the paddle 31, so that as the paddle is hinged upwardly by the motion of a wave the balance weight 35 is swung downwards by the arm. The balance weight therefore counters the weight of the paddle and of all other parts connected to move with it which could reduce the effect of the orbital energy available at the pump from the waves.

In Figure 1 the pump is shown in a condition, under the action of a wave on the paddle 31, in which the upper piston 7 is in a neutral position, having just moved downwards from an upper position and is in the process of charging the upper cylinder 9 with oil from the reservoir tank II. At the same time, the lower piston 8, having moved downwards, is in the process of driving oil, already charged into the lower cylinder 10 from the previous pump stroke, out of that cylinder and through the lower outlet manifold 21, lower outlet non-return valve 22 and feed pipes 16, 23 to the generator 17.

The next passing wave reverses the downward motion of the paddle and the direction of movement of the pistons in the cylinders. Upward movement of the upper piston 7 forces the oil charged into the upper cylinder 9 from the reservoir tank 11 out through the upper outlet manifold 12 and upper outlet non-return valve 15 into the upper feed pipe 16 and so to the generator 17, while the upper inlet non-return valve 13 is closed. Simultaneously, the lower piston 8, moving upwards, draws oil from the reservoir tank into the lower cylinder 10 through the lower inlet manifold 19 and lower inlet non-return valve 20, charging the lower cylinder with oil in readiness for the downwards movement of the lower piston 8 under the action of the paddle.

This completes the full operating cycle of the pump, providing a continuous supply of oil to the generator. However, while the pump continues to be operated the supply of oil to the generator may be interrupted, if desired, and diverted straight back to the reservoir tank 11 through the by-pass pipe 24 by operating the stop valves 25.

A series of pumps 1, each of the form described and operated individually by wave motion acting on its respective paddle, may be mounted on one or both sides of the hull of the vessel, in one or more rows, as shown in Figure 6 in which a wave profile W indicates the sequence of pump movements under the action of the paddles 31 generated by the wave motion.

As the pump, or each pump, is supported on the hull of the vessel above the waterline of the vessel, maintenance work may be carried out on it without undue difficulty while it is in place for use on the vessel. If necessary a cat walk may be rigged on the hull alongside the pump, or a series of the pumps, for ease of access to the pump or pumps.

Preferably, for ease of manufacture and assembly, the upper and lower inlet and outlet manifolds of the, or each, pump are cast, moulded or fabricated in metal or plastic material to be of square tubular section. Figures 7 to 10 of the drawings show in enlarged detail a typical form which manifolds and their non-return valves may take, in this case the lower inlet and outlet manifolds 19, 21, and their non-return valves 15, 22, of the lower cylinder 10. The lower piston 8 is indicated in the lower cylinder and shown fitted with a typical neck seal 38. Tubular square section parts 39, of the manifolds joined to the cylinder have circular end flanges 41, 42 by which they are fixed, for example by bolting, to corresponding circular valve plates 43, 44 of the non-return valves and circular end flanges 45, 46 of further square section parts 47, 48 of the manifolds which comiect respectively to the supply pipe 18 from the reservoir tank 11 and to the lower feed pipe 23 leading to the generator 17. The valve plates 43, 44 each have a square orifice 49, 50 in which a flapper plate 51, 52 is hinged by a pivot pin 53, 54 at the top of the orifice. A shroud plate 55, 56 provided in combination with each of the valve plates 43, 44 has a smaller square orifice 57, 58 than that in the respective valve plate so that the rim of the shroud plate around that orifice forms a shoulder on which the flapper plate 51, 52 can abut to close the orifice.

The smaller orifice therefore resnicts the flapper plate to being turned in one direction only in order to open that orifice and allow the oil to pass in one direction through the respective non-return valve.

Claims

CLAIMSI. A method of generating electricity by wave power in which a floating support on wave-generating water carries a reciprocating pump operatively connected to an electricity generator and a paddle which is hinged to be movable upwards and downwards relative to the floating support under the action of waves generated on the water, and which paddle is connected to a piston or cylinder of the pump to cause operating movement between the piston and cylinder whereby the electricity generator is driven.
2. A method according to Claim I in which the pump is supported by the floating support above the waterline of the support and the paddle is hingedly supported below the pump.
3. A method according to Claim 1 or Claim 2 in which the pump and paddle are mounted on a carrier attached to the floating support.
4. A method according to Claim 3 in which the carrier is adjustably attached to the floating support and/or the paddle is adjustably mounted on the carrier, for adjustment of the height of the paddle on the floating support relative to the waves generated on the water to vary the extent of the hinged movement of the paddle under the action of the waves.
5. A method according to any preceding claim in which the floating support is a floating vessel.
6. A method according to Claim 5 in which the pump and paddle are located on a side of the vessel.
7. A method according to Claim 5 in which the pump and paddle are located on an outrigger on the vessel.
8. A method according to any preceding claim in which the pump is held by a frame or casing carried by the floating support, either one of the piston and cylinder of the pump being fixed with respect to the frame or casing and the other being connected to the paddle for movement thereby relative to the frame or casing.
9. A method according to Claim 8 in which whichever one of the piston and cylinder is movable relative to the frame or casing has a cross-head coupled to the paddle by a connecting rod or rods and engaged with a guide or guides on the frame or casing to guide the piston or cylinder in its movement relative to the frame or casing.
10. A method according to Claim 8 or Claim 9 as dependent from Claim 4 in which the floating support includes a jib crane whereby the paddle and/or the frame or casing may be hoisted and lowered to adjust its position, or their positions, with respect to the floating support.
11. A method according to any of Claims 8 to 10 in which the electricity generator is mounted on or in the frame or casing.
12. A method according to any of Claims 8 to ii in which fluid is circulated by the pump from a reservoir and through a turbine to drive the electricity generator.
13. A method according to Claim 12 in which the reservoir and turbine are located on or in the frame or casing.
14. A method according to any preceding claim in which a balance weight is connected to the pump to counter the weight of the paddle and associated equipment which may have a detrimental effect of reducing orbital energy available at the pump from the action of waves generated on the water.
15. A method according to any preceding claim in which the reciprocating pump is used in conjunction with one or more other similar reciprocating pumps carried by the floating support and operatively connected to a or the electricity generator and to a or the hinged paddle movable upwards and downwards relative to the floating support under the action of waves generated on the water, thereby to cause operating movement between the piston and cylinder of the pump whereby the, or the respective, electricity generator is driven.
16. A method according to Claim 15 in which the reciprocating pumps are supported on the floating support at opposite sides of the support.
17. A reciprocating pump and paddle adapted for use in a method of generating electricity by wave power according to any preceding claim.
18. A reciprocating pump and paddle according to Claim 17 in which the pump and paddle are mounted on a carrier adapted to be attached to a floating support.
19. A reciprocating pump and paddle according to Claim 17 or Claim 18 of which the pump has more than one cylinder and/or piston.
20. A reciprocating pump and paddle according to Claim 19 as dependant from Claim 18 in which the pistons are connected to the paddle to be operated by the paddle, and the cylinders are fixed with respect to the carrier.
21. A reciprocating pump and paddle according to any of Claims 17 to 20 in which the pump has cylinder head manifolds at least in part made from or formed with rectangular section tubing.
22. A reciprocating pump and paddle according to any of Claims 17 to 21 which has fluid feed pipes at least in part made from or formed with rectangular section tubing.
23. A reciprocating pump and paddle according to any of Claims 17 to 22 which includes inlet and outlet valves opening to and from the or each cylinder having through apertures or passages of rectangular cross-section through which fluid flow is regulated.
24. A method of generating electricity by wave power substantially as described herein with reference to the accompanying drawings.
25. A reciprocating pump and paddle substantially as described herein with reference to the accompanying drawings.Amendments to the claims have been filed as follows 1. A method of generating electricity by wave power in which a floating support on wave-generating water carries a reciprocating pump operatively connected to an electricity generator and to a paddle which is hingedly supported in waves generated on the water to be movable upwards and downwards relative to the floating support under the action of orbital energy in the waves, and which paddle is connected to a piston or cylinder of the pump to cause operating movement between the piston and cylinder whereby the electricity generator is driven.2. A method according to Claim 1 in which the pump is supported by the floating support above the waterline of the support and the paddle is hingedly supported below the pump.3. A method according to Claim 1 or Claim 2 in which the pump and paddle are mounted on a carrier attached to the floating support.4. A method according to Claim 3 in which the carrier is adjustably attached to the floating support and/or the paddle is adjustably mounted on the carrier, for adjustment of the height of the paddle on the floating support relative to the waves generated on the water in which it is hingedly supported so as to vary the extent of the hinged movement of the paddle in the waves under the action of the orbital energy in the waves.5. A method according to any preceding claim in which the floating support is a floating vessel.6. A method according to Claim 5 in which the pump and paddle are located on a side of the vessel.7. A method according to Claim 5 in which the pump and paddle are located on an outrigger on the vessel.8. A method according to any preceding claim in which the pump is held by a frame or casing carried by the floating support, either one of the piston and cylinder of the pump being fixed with respect to the frame or casing and the other being connected to the paddle for movement thereby relative to the frame or casing.9. A method according to Claim 8 in which whichever one of the piston and cylinder is movable relative to the frame or casing has a cross-head coupled to the paddle by a connecting rod or rods and engaged with a guide or guides on the frame or casing to guide the piston or cylinder in its movement relative to the frame or casing.10. A method according to Claim 8 or Claim 9 as dependent from Claim 4 in which the floating support includes a jib crane whereby the paddle and/or the frame or casing may be hoisted and lowered to adjust its position, or their positions, with respect to the floating support.11. A method according to any of Claims 8 to 10 in which the electricity generator is mounted on or in the frame or casing.12. A method according to any of Claims 8 to 11 in which fluid is circulated by the pump from a reservoir and through a turbine to drive the electricity generator.13. A method according to Claim 12 in which the reservoir and turbine are located on or in the frame or casing.14. A method according to any preceding claim in which a balance weight is connected to the pump to counter the weight of the paddle and associated equipment which may have a detrimental effect of reducing orbital energy available at the pump from the action of waves generated on the water.15. A method according to any preceding claim in which the reciprocating pump is used in conjunction with one or more other similar reciprocating pumps carried by the floating support and operatively connected to a or the electricity generator and to a or the hinged paddle movable upwards and downwards relative to the floating support under the action of the orbital energy in the waves generated on the water, thereby to cause operating movement between the piston and cylinder of the pump whereby the, or the respective, electricity generator is driven.I16. A method according to Claim 15 in which the reciprocating pumps are supported on the floating support at opposite sides of the support.17. A reciprocating pump and paddle adapted for use in a method of generating electricity by wave power according to any preceding claim.18. A reciprocating pump and paddle according to Claim 17 in which the pump and paddle are mounted on a carrier adapted to be attached to a floating support.19. A reciprocating pump and paddle according to Claim 17 or Claim 18 of which the pump has more than one cylinder and/or piston.20. A reciprocating pump and paddle according to Claim 19 as dependant from Claim 18 in which the pistons are connected to the paddle to be operated by the paddle, and the cylinders are fixed with respect to the carrier.21. A reciprocating pump and paddle according to any of Claims 17 to 20 in which the pump has cylinder head manifolds at least in part made from or formed with rectangular section tubing.22. A reciprocating pump and paddle according to any of Claims 17 to 21 which has fluid feed pipes at least in part made from or formed with rectangular section tubing.S23. A reciprocating pump and paddle according to any of Claims 17 to 22 which includes inlet and outlet valves opening to and from the or each cylinder having through apertures or passages of rectangular cross-section through which fluid flow is regulated.24. A method of generating electricity by wave power substantially as described herein with reference to the accompanying drawings.25. A reciprocating pump and paddle substantially as described herein with reference to the accompanying drawings.