WATER FLOWING OVER A WATERBED

This invention relates to apparatus for generating electricity and, more especially, this invention relates to apparatus for generating electricity from water flowing over a waterbed.

There are many different types of known apparatus for generating electricity from water flowing over a waterbed. The water may be sea water or river water. Tides or ocean currents cause the water to flow, and it is this flow which is used by the apparatus in order to generate the electricity. Often the known apparatus is difficult to manufacture, install, operate and repair.

It is an aim of the present invention to reduce the above mentioned problem.

Accordingly, in one non-limiting embodiment of the present invention there is provided apparatus for generating electricity from water flowing over a waterbed, which apparatus comprises:

(i) a bridge over the water;

(ii) bridge supports which support the bridge and which extend into the waterbed;

(iii) a plurality of electrical generators which operate to generate electricity consequent upon receiving the flowing water; (iv) a base on which the electrical generators are mounted;

(v) connection means for electrically connecting the electrical generators together; and

(vi) an electricity sub-station for receiving the electricity from the connection means, and the apparatus being such that:

(vii) the base is positioned adjacent the bridge supports; and

(viii) the base operates independently of the bridge supports such that the base does not use the bridge supports for the functioning of the base, whereby the base and the electrical generators are unable adversely to compromise the structural integrity and operation of the bridge and the bridge supports.

The apparatus of the present invention is advantageous in that it is able to generate electricity from water flowing over a waterbed. The bridge provides ease of access for the installation of the base supports and the base. The bridge also provides ease of access for the installation and subsequent maintenance of the electrical generators. If at any time the base or one or more of the electrical generators need to be removed, then the bridge again provides a convenient location from which to work. The apparatus of the present invention is further advantageous in that the base operates independently of the bridge supports such that the base does not use the bridge supports for the functioning of the base, whereby the base and the electrical generators are unable adversely to compromise the structural integrity and operation of the bridge and the bridge supports. This in turn means that the base is able to be installed alongside or underneath existing bridges and also new bridges.

The apparatus of the present invention may include shock-absorbing means for absorbing shocks from earthquakes. Often bridges are constructed in earthquake zones and the shock-absorbing means advantageously enables shocks from earthquakes to be absorbed, thereby helping to provide continuing operational capacity in instances where manageable earthquake shocks are received.

The shock-absorbing means may be positioned on top of the base. The shock-absorbing means may be positioned elsewhere if desired.

The shock-absorbing means may be an open framework. The open framework may be a lattice structure. The open framework may be constructed for allowing the passage of debris through the open framework. Such a construction may be advantageous in avoiding the build up of debris of the type that might be flowing along the waterbed. If the debris were to build up and form a damn, this could put an undesirable strain on the apparatus of the present invention. The build up of debris may be prevented by using monitor means such for example as cameras to monitor the waterbed in the vicinity of the apparatus of the present invention, whereafter divers or other equipment may be employed to remove the debris. Such physical removal of debris is able to be kept to a minimum using the open framework.

The shock-absorbing means may be other than the open framework. Thus, for example the shock-absorbing means may be a hydraulic shock- absorbing means operating to provide hydraulic damping. Where the open framework is employed, then the open framework may be based on biomimicry using shapes found in nature.

The apparatus may be one in which the electrical generators are positioned on the shock absorbing means. Other positions for the electrical generators may be employed.

The apparatus may be one in which the base is formed of a plurality of base sections which are connected together. The provision of the base in the plurality of base sections facilitates ease of installation. It also facilitates removal of the apparatus when the apparatus is at the end of its life. Thus the base is able to be installed and/or removed with minimal damage to the environment. At the end of its life, there is no need to leave the base in position on the waterbed, which might further damage the environment. The base sections may pre-fit together. The base sections may be in a size that facilitates their installation and/or removal, for example bearing in mind considerations as to what size and weight of base sections can be lifted by a crane.

The base is preferably made from concrete. Other materials may be employed for the base. The apparatus may include base supports. The base supports may be column structures. Other structures for the base supports may be employed. The column structures may be piled columns. The column structures may be made of any suitable and appropriate materials or mixtures of materials, for example steel and/or concrete.

The connection means may be an electrical bus.

The apparatus may be one in which the electrical generators comprise lower electrical generators and upper electrical generators, in which the upper electrical generators electrically connect to the lower electrical generators, and in which the lower electrical generators electrically connect to the connection means. In this case, the lower electrical generators are advantageously a drop fit electrical connection to the connection means. This provides for ease of installation, and also removal if necessary for maintenance. Similarly, the upper electrical generators are preferably a drop fit electrical connection to the lower electrical connectors. Where there are several layers of upper electrical connectors, then the upper electrical connectors preferably connect to each other in the same way as they connect to the lower electrical connectors.

The electricity sub-station may be positioned away from the bridge. However, if desired, the electricity sub-station may be positioned on the bridge. Where the electricity sub-station is positioned away from the bridge, then it is preferably positioned adjacent the bridge, thereby providing for general convenience of access. The electrical generators may each comprise a rotor, a stator, and a housing. Other types of electrical generators may be employed, for example hydraulic paddle-type electrical generators.

Where the electrical generators each comprises a rotor, a stator and a housing, then the apparatus may be one in which the housing is a multi-sided housing constructed such that the electrical generators are stably connectable together, and in which the housing is open at both ends so that the water can flow in either direction through the housing. Preferably the housing is hexagonal. Other shapes for the housing may be employed.

The apparatus may be one in which each of the open ends of the housing defines a venturi passage for increasing the water flow for the electrical generators. The venturi passage may be defined within the hexagonal or other outer shape of the housing.

The stator may be mounted in at least a part of the housing. Other positions for the stator may be employed.

The apparatus may be one in which the rotor comprises a plurality of magnets positioned around the periphery of the rotor, in which the magnets are encased in a protective material which protects the magnets from the water, and in which the rotor has vanes which cause the rotor to rotate within the stator as the water flows through the housing. The protective material may be a sheet material or a mastic material. Where the protective material is a sheet material, then it may be a para-aramid synthetic fibre, for example Kevlar (Registered trade mark). Where magnets are employed, then the magnets may be located in pockets. Preferably each magnet has its own pocket. However two or more magnets may be located in a single pocket if desired.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which:

Figure 1 is a side view of first apparatus for generating electricity from water flowing over a waterbed;

Figure 2 is a perspective view of part of the apparatus shown in Figure

1 ;

Figure 3 is a front view of the part of the apparatus shown in Figure 2;

Figure 4 is a perspective view of another part of the apparatus as shown in Figure 1 ;

Figure 5 is a perspective view from the left, front and underneath of part of the apparatus as shown in Figure 4;

Figure 6 shows in more detail the left hand part of the apparatus as shown in Figure 4;

Figure 7 is a side sectional view the apparatus as shown in Figure 1 ;

Figure 8 illustrates the connection of lower electrical generators to shock-absorbing means forming part of the apparatus shown in Figure 1 ;

Figure 9 shows the electrical connection of upper electrical generators to lower electrical generators in the apparatus as shown in Figure 1 ; and

Figure 10 is a perspective view showing part of second apparatus for generating electricity from water flowing over a waterbed.

Referring to Figures 1 - 9, there is shown apparatus 2 for generating electricity from water 4 flowing over a waterbed 6. The apparatus 2 comprises a bridge 8 over the water 4. The bridge supports 10 support the bridge 8. The bridge supports 10 extend into the waterbed 6.

The apparatus 2 further comprises a plurality of electrical generators 12 which operate to generate electricity consequent upon receiving the flowing water 4. As shown in Figure 5, connection means 16 electrically connects the electrical generators 12 together. An electricity sub-station 18 shown in Figure 1 receives the electricity from the connection means 16.

The apparatus 2 is such that the base 14 is positioned adjacent the bridge supports 10. The base 14 operates independently of the bridge supports 10 such that the base 14 does not use the bridge supports 10 for the functioning of the base 14. In this manner, the base 14 and the electrical generators 12 are unable adversely to compromise the structural integrity and operation of the bridge 8 and the bridge supports 0.

The apparatus 2 is able to take advantage of the bridge 8 for the installation and maintenance of the electrical generators 12, the base 14 and the connection means 16. This is able to be achieved without adversely affecting the structural integrity and operation of the bridge 8 and the bridge supports 10, this being due to the fact that the base 14 operates independently of the bridge supports 10 such that the base 14 does not use the bridge supports 10 for the functioning of the base 14. The bridge 10 may be an existing bridge or it may be a new bridge.

The apparatus 2 is such that it includes shock-absorbing means 20 for absorbing shocks from earthquakes. The shock-absorbing means 20 is positioned on top of the base 14. The shock-absorbing means 20 is an open framework in the form of a lattice structure. The lattice structure is such that it allows debris of the type that may roll along the waterbed 6 due to the current of the water 4 to pass through the lattice structure. This helps to avoid the electrical generators 12 and the base 14 causing a build up of debris and thereby creating a damn which could create unwanted forces on the bridge supports 10.

The base 14 is formed of base sections 22, for example as shown in Figure 5. The base sections 22 may be formed in any suitable and appropriate manner. Thus, for example, the base sections 22 may be prefabricated from concrete or another material and then lowered in position for connection together. Alternatively, the base sections 22 may be in the form of an open container which is subsequently filled with ballast. The base sections 22 may be connected together by any suitable and appropriate connection means. The base 14 is preferably made of concrete but other materials may be employed.

The base 14 is shown in the drawings as resting on the waterbed 6. If desired, the base 14 may have base supports which may be like the bridge supports 10. Thus, for example, the base supports may extend downwardly from the base 14 and into the waterbed 6. The base supports may be column structures. The column structures may be piled columns or other structures. The base supports may be made of metal such for example as steel, or they may be made of concrete or other appropriate materials.

The connection means 16 is an electrical bus. As shown in Figure 5, the electrical means 16 comprises a main bus 24 with individual connection lines 26. Each connection line 26 has a connector 28 which may be a plug-in connector to one of the electrical generators 12. The main bus 24 goes to an electrical junction box 30. The electricity from the electrical junction box 30 may extend up cables 32 secured to the bridge supports 10. The cables 32 lead to the electricity sub-station 18 as can best be appreciated from Figure 1.

Figure 5 illustrates how the electrical generators 12 comprise lower electrical generators 34 and upper electrical generators 36. The lower electrical generators 36 electrically connect to the connectors 28 as described above. The upper electrical generators 36 electrically connect to the lower electrical generators 34, for example by similar connectors 28. Advantageously the connectors 28 are drop fit electrical connectors in order to enable ready assembly of the electrical generators 12 on the shock- absorbing means 20, and also to allow for easy removal of any one of the electrical generators 22 if this should be necessary for maintenance and repair purposes.

The electricity sub-station 18 is shown remote from but adjacent to the bridge 8. The electricity sub-station 18 may be positioned elsewhere if desired.

The electrical generators 12 each comprises a rotor 38, a stator 40 and a housing 42. The housing 42 is a multi-sided housing constructed such that the electrical generators 12 are stably connectable together. The housing 42 is hexagonal. The housing 42 is open at both ends 44, 46. As can best be appreciated from Figure 7, with the housing open at both of the ends 44, 46, the water 4 can flow in either direction through the housing 42. The electrical generators 12 may be constructed in a variety of ways. Thus, for example, the stator 40 may be inside at least a part of the housing 42. In one embodiment of the invention, the rotor 38 may comprise a plurality of magnets positioned around the periphery of the rotor. The magnets may be encased in a protective material which protects the magnets from the water 4. The rotor 38 may have vanes 48 as shown in Figures 4 and 5 to cause the rotor 38 to rotate within the stator 40 as the water 4 flows through the housing 42.

The open ends 44, 46 of the housing 42 define a venturi passage 50 which increases the water flow for the electrical generators 12. More specifically, as best shown in Figure 5, each venturi passage 50 leads to a central parallel sided section 52 inside the housing 40. The rotor 28 and the stator 40 are located in this parallel sided section 52, and thus the rotor 38 receives the full force of the water 4 with its increased speed caused by the venturi passages 50.

Figure 8 shows how the lower electrical generator 34 makes an electrical connection via the connection means 16 to the shock-absorbing means 20. Figure 8 also shows how the upper part of the lower electrical generator 34 has part of connection means 54 for enabling one of the upper electrical generators 36 to connect to the lower electrical generator 36. The completed electrical connection means 54 is shown in Figure 9. As shown in Figure 8, the lower electrical generator 34 may rest on pads or seals 56 to act as cushioning means against the shock-absorbing means 20. Similarly Figure 9 shows how the upper electrical generator 36 may rest on lower electrical generators 34 via similar pads or seals 56.

Referring now to Figure 10, there is shown a part 58 of second apparatus of the present invention. The part 58 is shown like the part of the apparatus 2 shown in Figure 5, but viewed from the other side. Similar parts have been given the same reference numerals for ease of comparison and understanding. In Figure 10, the part 58 is shown with shock-absorbing means 60 which extends completely around the electrical generators 12, as opposed to just being located at the bottom of the electrical generators 12 as in the case of the shock-absorbing means 20.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Thus, for example, in Figure 1 the bridge 8 is shown extending between two banks 62, 64. The bridge 8 may extend between other structures and generally the bridge may be used for any suitable and appropriate purpose, including use by traffic and/pedestrians and/or essential services such for example as water, electricity and sewage services. The bridge may thus be regarded as a simple bridge, a causeway or a bypass.

The apparatus of the present invention as shown in the drawings may be such that the base 14 has suitable lifting points and/or mooring points. The lifting points and/or the mooring points may allow suitable connection and disconnection of the various parts of the apparatus 2 by a remotely operated vehicle, or a crane mounted on the bridge 8 or on a barge (not shown). Where metal is employed for the bridge supports 10, the base 14 and any base supports extending downwardly from the base 14 into the waterbed 6, then the metal may be protected by painting and cathode protection.

For maintenance and electrical transmission, an independent deck may be constructed, or an unused maintenance deck for existing structures may be employed. For new bridge constructions in the design phase, the independent parts of the apparatus of the present invention for generating the electricity will not add any additional cost for enhanced bridge reinforcements. Additional rows of the electrical generators 12 may be added, in dependence upon the amount of electricity required to be generated, and also in dependence upon clearance requirements from the surface of the water 4 during tidal fluctuations, or near shore bathymetry and tidal currents. The electrical generators 12 may be regarded as caissons.

The electrical generators 12 may be multiple array units giving 1.5 megawatts. Each electrical generator 12 may be designed to easily be lifted by a crane from an installation vessel or, if appropriate, from the infrastructure of the bridge 8. The six-sided design of the housings 42 enables the electrical generators 12 easily to be located together to provide overall integrity against the water flow. The apparatus 2 may be provided alongside the bridge supports 10 and/or in line with the bridge supports 10 so that they will then be directly under the bridge 8. The bridge supports 10 are able to be used for taking the generated electricity from the main bus 24 to the electricity substation 18. The bridge supports 10 may also be used for information transmission lines. The bridge 8 may be such that underneath its deck it has appropriate connections for receiving the cables 32 leading to the electricity sub-station 18 and/or information cables. The lower surface of the bridge deck may also include lifting equipment for installation and/or repair and/or removal of the individual electrical generators 12.

The apparatus shown in the drawings may be constructed to be modular, for example using concrete base boxes, and lattice steel cradle electrical generators. At the end of its life, if the electrical generators are not to be replaced with updated technology, then the apparatus 2 can easily be removed, thereby leaving the waterbed 6 substantially in its original condition. There will be no need to leave parts of the apparatus 2 on the waterbed to the detriment of the environment. Individual components shown in the drawings are not limited to use in their drawings and they may be used in other drawings and in all aspects of the invention.