IE20150070A1

IE20150070A1 - Means of applying and removing ballast automatically and controllably to floating wave energy converting, devices and optimizing energy capture

Info

Publication number: IE20150070A1
Application number: IE20150070A
Authority: IE
Inventors: Bielenberg John
Original assignee: Bielenberg John
Priority date: 2015-02-27
Filing date: 2015-02-27
Publication date: 2016-05-04
Also published as: IE86648B1

Abstract

The invention relates to automatic as well as controlled ballasting and deballasting floating wave energy conversion devices, as well as describing some devices and aids to the their optimization.

Description

Means of applying and removing ballast automatically and controllably to floating wave energy converting (WEC) devices.

Background to the invention The slow moving but high force nature of ocean wave energy requires high inertia devices to harvest this energy but the heavy weights required for high inertia become difficult to moor in storm conditions. The patent allows heavy weights to be accumulated and jettisoned automatically and controllably at the appropriate time, by floating devices suitable for wave energy conversion.

Statement of invention A means of ballasting and rapidly deballasting wave energy conversion devices. Floating containers on sea like wave conditions, mechanically connected to convert rocking motion into unidirectional rotary motion, have extensions of their sides and ends that can be made to project downwards into the water. For delivery to site purposes the extensions are preferably an additional skin to the sides and ends of the container. Near the top of these extensions are air valves that allow the air captured between the extensions and the bottom of the container to escape, thereby increasing the upward and downward inertia of the container. In the event of excessive upward movement of a portion of the container the bottom of the extensions exit the water allowing air to enter the space between the extensions and the bottom of the container. The air valves may be purely passive or may be actuated to open, thereby allowing air in. Preferably the containers are made to freight container dimensions and fittings for manufacturing and transport purposes and can be joined on site for larger compound assemblies. It is possible to use the concept on cylindrical devices also.

Brief description of the drawings. 1/7. Shows downward extensions of typical container and detail of passive and controlled air valve as well as power take off means of wave energy conversion (WEC) device. 2/7. Shows an arrangement of a wave energy conversion device and mooring arrangements. 3/7. Shows a further arrangement of a wave energy conversion device. 4/7. Shows a further arrangement of a wave energy conversion device. /7. Shows a further arrangement of a wave energy conversion device. 6/7. Shows possible mooring arrangements. 7/7. Shows an optional torque smoothing mechanism.

Detailed description of drawings.

Fig 1a, 1b and 1c show power take off arrangement as well as side and end extensions and position of passive air valve in top, side and end elevational views. Detail of passive air valve is in Fig 1d and actuated air valve in Fig 1e. This drawing should be seen in conjunction with drawings 2/7, 3/7, 4/7 and 5/7. Legs (1) of H frame (2) are rigidly connected to shafts (3) which pass into floating containers (4). Power take off means comprising two large transmission chain sprockets (6) mounted on shafts (3) drive a gear box shaft (7) on which is mounted two smaller transmission sprockets (8) which have internal sprag clutches which allow only unidirectional rotation. Chain drive from one of the large sprockets (6) passes an idler sprocket (9) before engaging with one of the smaller transmission sprockets (8) as shown. Backward and forward rotation of shaft 3 results in unidirectional rotation of shaft (7).

Downward extensions of side (10) and end (11) walls of the containers have passive air valves (12) shown in detail in Fig 4d , which shows holes (13) in side walls covered by a flexible membrane (14) retained by a supporting flat (15) bolted through the membrane to the side wall (10). The membrane can deflect outwards only and cover the holes otherwise. Fig 4d shows a typical active air valve with a linear actuator (41) operating a sliding piece (42) between guides (43) that covers or uncovers a hole (44). 2/7. Shows a plan view of a WEC device in Fig 2a, of compound floating containers (18) held rotationally on shafts (3) between legs of H frame (2). Downward extensions (10) and (11) are used as shown in side view Fig 2b. Additionally, in Fig 2c and 2d, is shown a detailed method of securing the complete WEC assembly to a mooring system, allowing multiple units to be deployed in chain formation, shows a hinge detail assembly. The centre (20) clamps onto a steel cable (21). A rubber bush (22) is held between the centre (20) and the outer portion of the hinge (23) which is secured to the H frame (2). If required for point application the WEC is additionally equipped with a U frame, not shown, pivotally attached to {23} for connection to a mooring line (28). The sea surface is (37). 3/7. Shows a plan view of a wave energy conversion (WEC) device in Fig 2a. Two floating containers (4) are according to details shown in drawing 1/7 and are joined together. Shafts (3) are rigidly connected to connecting pieces (33) the other ends of which are rigidly connected rigidly to a single empty container (34) complete with downward extensions (10) and (11). For point application a tether (30) can be attached as shown. For chain deployment, hinges (19) can be used. Fig 2b shows a side view of the assembly.

Double acting hydraulic cylinders (39) generating system oil pressure which can be converted to rotational power by well-known means is an alternative power take off system. 4/7. Shows a plan view, Fig 4a, of a WEC device and a side view Fig 4b. This technology is known and comprises a pair of floating containers (37) joined together at hinge points (38). Flexing at the hinge points (38) results in axial movement in double acting hydraulic cylinders (39) generating system oil pressure which can be converted to rotational power by well-known means. For point application a tether (30) can be attached as shown. For chain deployment, hinges (19) can be used. /7. Shows a plan view, Fig 5a, of a WEC made of a floating container (40) complete with side (10) and end (11) extensions and air valve (12) held rotationally on shafts (3) between legs (25) of a U frame (26) to which is attached a baffle plate (27) to which may be attached a mooring line (28). A side view is shown in Fig 5b. The baffle plate (27) ensures rotation of shafts (3). 6/7. Shows, in Fig 6a, plan view of chain deployment of multiple WEC devices (46) along a steel cable (21) suitably mounted between strong points (45). Fig 6b shows cable (21) supported in mid length by a further cable (31) suitably constrained by strong points similar to (45). 7/7. Fig 7a shows a torque smoothing mechanism which might be interposed in the chain drive system described in drawing 1/7. Small input sprockets (8), complete with unidirectional sprag clutches, drive input shaft (32) which is connected 1o circular plate (33) which is connected to a cylinder, the other end of which has a bearing (34), similar to that which input shaft (32) is mounted, which can rotate on the input shaft (7) of gear box. On this shaft (7) is fixed a circular plate (46). Holes in this plate and also plate (33) allow U bolts (47) to fasten on the end of a spring (48) which is used torsionally. The whole unit is housed in a cylindrical housing (35) which can bolt to the front of the gearbox.

Preferably, the containers referred to above are sized and provided with fittings, to allow them to be transported as freight containers. Multiples of these can be fixed together as required. This allows simple manufacturing in good working conditions.

Claims

1. A system for ballasting and rapidly deballasting wave energy conversion devices (WEC) comprising: compound floating containers held rotationally on shafts (3) between legs of H frame (2), having downward side wall (10) and end wall (11) extensions; a power take off arrangement, comprising two large transmission chain sprockets (6) mounted on the shaft (3) to drive a gear box shaft (7) on which is mounted two smaller transmission sprockets (8) which have internal sprag clutches which allow only unidirectional rotation, wherein a chain drive from one of the large chain sprockets (6) passes an idler sprocket (9) before engaging with one of the smaller transmission sprockets (8) wherein backward and forward rotation of the shaft (3) results in unidirectional rotation of the gear box shaft (7); air valve (12), which can be passive or actuated, in which holes (13) in side walls are covered by a flexible membrane (14) retained by a supporting flat (15) bolted through the membrane to the side wall (10), wherein the membrane (14) can deflect outwards only and cover the holes, optionally, wherein the actuated air valve (12) uses a linear actuator (41) operating a sliding piece (42) between guides (43) that covers or uncovers a hole (44) that allow the space between the downward projecting sides (10) and ends (11) to fill with water ballast which will only be released if air is allowed in under the downwards projected sides or ends, such as would occur in storm conditions; securing means for WEC assembly to a mooring system, allowing multiple units to be deployed in chain formation, using a hinge detail assembly, wherein the hinge centre (20) clamps onto a steel cable (21), a rubber bush (22) is held between the centre (20) and the outer portion of the hinge (23) which is secured to the H frame (2), wherein optionally, if required for point application, the WEC is additionally equipped with a U frame, pivotally attached to the hinge (23) for connection to a mooring line (28).

2. A system for ballasting and rapidly deballasting wave energy conversion devices (WEC) as claimed in claim 1, wherein, in one embodiment, the compound floating containers are joined together, wherein shafts (3) are rigidly connected via connecting pieces (33) to a single empty container (34) complete with downward sidewall (10) and endwall extensions (11), wherein for point application a tether (30) can be attached or for chain deployment, hinges (19) can be used.

3. A system for ballasting and rapidly deballasting wave energy conversion devices (WEC) as claimed in claim 1 wherein, in a further embodiment, at least two compound floating containers are joined together at hinge points (38), wherein flexing at the hinge points (38) results in axial movement in double acting hydraulic cylinders (39), generating system oil pressure which can be converted to rotational power by well-known means.

4. A system for ballasting and rapidly deballasting wave energy conversion devices (WEC) as claimed in claim 1 wherein, in a further embodiment, the compound floating container, complete with downward sidewall (10) and endwall extensions (11) and air valve (12), is held rotationally on shafts (3) between legs (25) of a II frame (26) to which is attached a baffle plate (27) which may be further attached a mooring line (28), wherein the baffle plate (27) ensures rotation of shaft (3).

5. A series of WEC devices, used in a system for ballasting and rapidly deballasting wave energy conversion devices (WEC) as claimed in any preceding claim, positioned along a steel cable (21) suitably mounted between strong points (45), wherein the cable (21) may be supported in mid length by a further cable (31).

6. A torque smoothing mechanism, in use with a system for ballasting and rapidly deballasting wave energy conversion devices (WEC), as claimed in claims 1 to 4, which may be interposed in the chain formation securing system, wherein, small input sprockets (8), complete with unidirectional sprag clutches, connect to a drive input shaft (32) which is linked to circular plate (33) and a cylinder which can rotate on the input shaft (7) of gearbox, this shaft (7) being fixed a circular plate (46), wherein holes in this plate (46) and also plate (33) allow U bolts (47) to fasten on the end of a spring (48) which is used torsionally, the whole unit, housed in a cylindrical housing (35), being bolted to the front of the gearbox.

7. A system for ballasting and rapidly deballasting wave energy conversion devices (WEC) as described herein with reference to the accompanying drawings.