WAVE ENERGY CONVERSION SYSTEM

Abstract

A WEC module for connection to a WEC system having a power take-off (PTO) configured to generate electricity in response to fluid flow in a fluid flow path of the system. The module includes a mounting portion for releasably mounting the module to the system, a deformable sealing member configured to provide a sealed fluid connection between the module and the fluid flow path, and a working surface configured to exchange, in response to wave motion, a working fluid with the fluid flow path via the sealed fluid connection. Also disclosed is a WEC system and a method of deploying the WEC module. Also disclosed is an installation device for a working surface and a method of installing a working surface.

Claims

1-44. (canceled)

45. A wave energy (WEC) module for connection to a WEC system having a power take-off (PTO) configured to generate electricity in response to fluid flow in a fluid flow path of the system, the WEC module comprising: a mounting portion for releasably mounting the module to the system; a deformable sealing member configured to provide a sealed fluid connection between the module and the fluid flow path; and a working surface configured to exchange, in response to wave motion, a working fluid with the fluid flow path via the sealed fluid connection.

46. A WEC module according to claim 45 comprising a support frame defining an aperture that is sealed by the working surface.

47. A WEC module according to claim 46 wherein the support frame comprises a module sealing face for sealing against a corresponding system sealing surface of a cell body of the system, the deformable sealing member disposed on the module sealing face.

48. A WEC module according to claim 47 wherein the module sealing face forms part of a moveable portion of the support frame that is moveable between a retracted position and a sealing position in which the deformable sealing member seals against the system sealing face.

49. A WEC module according to claim 46 wherein the support frame comprises a guide portion configured to guide the module onto a base structure of the system, one or more surfaces of the guide portion tapering outwardly in a direction of movement of the module during connection to the base structure.

50. A WEC module according to claim 45 comprising a cell body defining an aperture, the working surface sealing the aperture such that a chamber for storage of the working fluid is defined by the cell body and the working surface.

51. A WEC module according to claim 50 wherein the module comprises a fluid exchange port for exchanging fluid between the chamber and the fluid flow path via the sealed connection, the fluid exchange port comprising a module sealing face for sealing with a corresponding system sealing face of the fluid flow path, and wherein the deformable sealing member is disposed on the module sealing face.

52. A WEC module according to claim 51 wherein the module sealing face of the fluid exchange port forms part of a moveable portion of the fluid exchange port that is moveable between a retracted position and a sealing position in which the deformable sealing member seals against the system sealing face.

53. A WEC module according to claim 45 wherein the deformable sealing member is inflatable.

54. A WEC module according to claim 45 wherein the module is configured such that, when mounted to the system, the working surface extends along a substantially horizontal plane.

55. A WEC module according to claim 45 wherein the mounting portion is a first mounting portion and the module comprises a second mounting portion spaced from the first mounting portion, one or both of the first and second mounting portions being moveable such that a distance between the mounting portions can be altered.

56. A WEC system comprising: a power take-off (PTO) device for generating electricity from flow of a working fluid; a fluid flow path in fluid connection with the PTO device; a plurality of WEC modules, each module fluidly connected to the fluid flow path and configured to exchange working fluid with the fluid flow path in response to wave motion; and a plurality of fluid exchange ports, each fluid exchange port releasably connecting a respective module to the fluid flow path and comprising a deformable sealing element arranged to seal the connection between the respective module and the fluid flow path.

57. A WEC system according to claim 56 wherein the plurality of WEC modules are mounted to one another, such that the fluid flow path is defined by the WEC modules.

58. A WEC system according to claim 56 wherein each WEC module is comprising a support frame defining an aperture that is sealed by the working surface.

59. A WEC system according to claim 56 wherein each WEC module is comprising a cell body defining an aperture, the working surface sealing the aperture such that a chamber for storage of the working fluid is defined by the cell body and the working surface.

60. A WEC system according to claim 57 wherein the WEC modules are mounted to a base structure and the fluid flow path is defined by at least one duct of the base structure.

61. A WEC system according to claim 56 wherein the fluid flow path comprises a debris separator upstream of the PTO, and wherein: the debris separator comprises a grille and debris trap disposed in horizontal portion of the fluid flow path, and the grille is inclined across the fluid flow path so as to at least partly overhang debris trap; or the debris separator comprises a grille extending across a vertical portion of the fluid flow path so as to be oriented substantially horizontally and a debris trap disposed below grille.

62. A WEC system according to claim 56 wherein each WEC module comprises first and second mounting portions for engagement with respective first and second receiving portions of the base structure, and wherein at least one of the mounting portions is moveable such that the mounting portions are moveable between a retracted and expanded position.

63. A WEC system according to claim 62 wherein the base structure comprises a plurality of docking stations, each for receipt of a respective WEC module, and each docking station comprises first and second receiving portions for engagement with the first and second mounting portions of the respective WEC module.

64. A WEC system according to claim 63 wherein the first receiving portion comprises a hook-shaped recess having an entrance region and a locking region that extends perpendicularly to the entrance region.

Description

SUMMARY OF THE FIGURES

[0151] So that the invention may be understood, and so that further aspects and features thereof may be appreciated, embodiments illustrating the principles of the invention will now be discussed in further detail with reference to the accompanying figures, in which:

[0152] FIG. 1 is a perspective view of a first embodiment of a WEC system;

[0153] FIG. 2 is a perspective view of a second embodiment of a WEC system;

[0154] FIGS. 3A and 3B are end views of a third embodiment of a WEC system;

[0155] FIG. 3C is a perspective view of the third embodiment of the WEC system;

[0156] FIG. 4 is a schematic view of a connection between a WEC module and system according to a first embodiment;

[0157] FIG. 5 is a schematic view of a connection between a WEC module and system according to a second embodiment;

[0158] FIGS. 6A and 6B are schematic views of a connection between a WEC module and system according to a third embodiment;

[0159] FIGS. 7A and 7B are schematic views of a connection between a WEC module and system according to a fourth embodiment;

[0160] FIGS. 8, 9 and 10 are schematic views of blanking arrangements according to various embodiments;

[0161] FIGS. 11 and 12 are schematic views of drainage arrangements according to first and second embodiments;

[0162] FIGS. 13, 14 and 15 are schematic views of debris separation according to three embodiments;

[0163] FIGS. 16A and 16B are schematic views showing mounting of a WEC module to a base structure according to a first embodiment;

[0164] FIGS. 17A and 17B are schematic views showing mounting of a WEC module to a base structure according to a second embodiment;

[0165] FIG. 18 is a schematic view showing mounting of a WEC module to a base structure according to a third embodiment;

[0166] FIG. 19 is a schematic view showing mounting of a WEC module to a base structure according to a fourth embodiment;

[0167] FIGS. 20 and 21 are respective exploded and detailed views of a WEC system according to a fourth embodiment;

[0168] FIGS. 22A and 22B are respective side and front views of a WEC module according to a fifth embodiment;

[0169] FIG. 23A to 23H are views depicting a process for deploying a WEC module to a base structure;

[0170] FIG. 24A is a sectional view of a WEC system according to a sixth embodiment;

[0171] FIG. 24B is a perspective view of a support frame of the WEC system of the sixth embodiment;

[0172] FIGS. 25A and 25B are schematic views illustrating installation of a working surface by an installation device; and

[0173] FIGS. 26A to 26D illustrate seventh, eighth, ninth and tenth embodiments of a WEC module.

DETAILED DESCRIPTION OF THE INVENTION

[0174] Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

[0175] FIG. 1 illustrates a wave energy conversion (WEC) system 100 that is configured to be submerged in a body of water. The system 100 comprises a plurality of modular WEC cells 101 mounted to a base structure 102. In particular, each cell 101 forms part of a module 108 that mounts to the base structure 102. Each module 108 includes two cells 101 in a back-to-back arrangement. The system 100 comprises a fluid flow path 103 that is partly defined by the cells 101 (or modules 108) and partly defined by the base structure 102. That is, each module 108 comprises two vertically spaced corresponding cell duct portions 104 formed therein, such that when the modules 108 are mounted to the base structure 102, the cell duct portions 104 align to form two continuous linear ducts.

[0176] The base structure 102 comprises an energy converter, in the form of a turbine 105. This turbine 105 is disposed in a U-shaped duct portion 106 that forms part of the base structure 102. Openings of the U-shaped duct portion 106 align with corresponding openings of the duct portions 104 of the adjacent (end) module 108. In this way, the U-shaped duct portion 106 of the base structure 102 connects the two linear ducts formed by the mounted modules 108. Thus, the fluid flow path 103 is formed by the combination of the cell duct portions 104 and the U-shaped duct portion 106.

[0177] Each cell 102 comprises a cell body 133 and a working surface in the form of a membrane 107 that extends across an opening that is formed in the cell body 133. The membrane 107 is mounted at a sloped portion of the cell body 133 so as to be angled away from a vertical orientation. Although not apparent from the figure, the cell body 133 and the membrane 107 define a chamber that contains a working fluid. This chamber of each cell 102 is in fluid communication with the fluid flow path 103, such that when the membrane 107 flexes in response to wave motion it drives air from the chamber and into the fluid flow path 103. In this way, working fluid is moved along the fluid flow path 103 to the turbine 105 (by movement of the membranes 107) so as to cause rotation of the turbine 105, which generates electricity.

[0178] FIG. 2 illustrates a variation of the system 100 shown in FIG. 1. The system 100′ again includes a plurality of WEC cells 101 mounted to a base structure 102. In the presently illustrated system, however, the cells 101 are separated from one another via mounting blocks 109 that form part of the base structure 102 (protrude upwardly from a planar slab of the base structure 102) and that are located intermediate each of the modules 108. Each mounting block 109 comprises intermediate duct portions 110 that align and seal with the duct portions 104 of the modules 108, so as to form the fluid flow path 103.

[0179] In the embodiments of FIGS. 1 and 2, when one module 108 is removed from the system 100, 100′ the fluid flow path 103 is interrupted (i.e. the portion of the fluid flow path 103 defined by the module 108 is removed). In the variation shown in FIGS. 3A, 3B and 3C, that is not the case.

[0180] In the system 100″ of FIGS. 3A-3C, the base structure 102 comprises a complete fluid flow path 103 defined by a duct 106 that extends comprises two legs extending centrally along the base structure 102 that are connected by a U-shaped portion in which the turbine 105 is disposed. The duct 106 comprises a plurality of openings 111 spaced therealong that fluidly connect with the cell chambers when the modules 108 are mounted to the base structure 102. In particular, each module 108 comprises two fluid exchange ports 112 that interface with the openings 111 of the duct 106 so as to create a sealed path for fluid exchange between the cell chambers and the fluid flow path 103. In particular, each module 108 is positioned over the top of the duct 106 of the base structure 102 and the ports 112 engage the openings 111 of the duct 106. The nature of this connection will be described further below.

[0181] As the fluid flow path 103 is fully defined by the base structure 102, removal of a module 108 from the base structure does not interrupt the fluid flow path 103. In this way, the system 100″ is able to operate regardless of whether a module 108 has been removed (e.g. for repair or maintenance). As should be appreciated, in the above described (and illustrated) embodiments, each module 108 comprises two cells 101. In other embodiments, however, each module 108 may comprise a single cell 101 (such that the cell 101 itself is a module 108).

[0182] FIGS. 4 to 7B provide various exemplary embodiments of how a cell 101 (or module 108) may be sealed to the fluid flow path 103 which, although not shown, may form part of a base structure such as one of those described above. In each of these embodiments, the cell 101 comprises a fluid exchange port 112 for exchange of working fluid with the fluid flow path 103. This fluid exchange may be in the form of discharge of working fluid from the chamber of the cell 101, receipt of fluid into the chamber from the fluid flow path 103, or both discharge and receipt of working fluid (i.e. depending on the movement of the membrane 107).

[0183] In the embodiment of FIG. 4, the fluid exchange port 112 comprises a module sealing face 113 in the form of a planar surface. The module sealing face 113 is substantially annular, so as to extend about an opening of the fluid exchange port 112. Upon mounting of the cell 101 to e.g. a base structure, the module sealing face 113 interfaces with a corresponding duct sealing face 114 that forms part of an opening 111 to a duct 106 defining the fluid flow path 103. Both sealing faces 113, 114 are parallel to one another and extend in respective planes that are generally perpendicular to fluid flow through the fluid exchange port 112.

[0184] A deformable sealing member 115 is mounted to the module sealing face 113. Thus, when the sealing faces 113, 114 are brought together (i.e. when a cell is engaged with the fluid flow path 103), the sealing member 115 is sandwiched between the sealing faces 113, 114. This facilitates sealing between the cell 101 and the fluid flow path 103, so as to prevent fluid ingress therein.

[0185] In order to further facilitate this sealing between the cell 101 and the fluid flow path 103, the cell comprises a moveable portion 116. The module sealing face 113 forms part of this moveable portion 116, which is moveable along an adjustment axis that is generally parallel to fluid flow through the fluid exchange port 112, and perpendicular to the sealing faces 113, 114. The moveable portion 116 has a circumferential section 117 that extends circumferentially about the fluid exchange port 112, and a radial section 118 that extends radially from a distal end of the circumferential section 117. The module sealing face 113 forms an outer surface of this radial section 118. The circumferential section 117 snugly fits about the port 112, such that it is in sliding contact with an outer surface of the fluid exchange port 112. Any gap between the port 112 and the moveable portion 116 is sealed by annular sliding sealing rings 119 disposed therebetween.

[0186] The position of the moveable portion 116 is adjustable by way of an adjustment mechanism comprising a plurality of circumferentially spaced threaded rods 120 and corresponding fasteners 121 engaged therewith. Each rod 120 projects rearwardly (i.e. away from the sealing faces 113, 114) from the radial section 118 of the moveable portion 116 and through a corresponding aperture formed in a radially projecting flange 122 of the fluid exchange port 112. In this way, adjustment of the position of the fasteners 121 with respect to each rod 120 alters the axial position of the moveable portion 116 with respect to the fluid exchange port 112. In this way, the axial position of the module sealing face 113, with respect to the port 112, can be adjusted.

[0187] FIG. 5 illustrates a similar embodiment to that shown in FIG. 4 and therefore corresponding reference numerals have been used. This embodiment only differs in that the deformable sealing member 115′ is tubular so as to contain an internal (ring-shaped) cavity 123. In this embodiment the sealing member 115′ may be inflated by introducing fluid into the cavity 123. Inflation of the sealing member 115′ ensures that any gap between the sealing faces 113, 114 is sealed by the sealing member 115′.

[0188] FIGS. 6A and 6B illustrate a further embodiment that, again, has similar features to those described above. This embodiment differs, however, in that the moveable portion 116 is biased in a direction away from the flange 122 by way of a plurality of compression springs 124 that surround each rod 120 and extend between the port flange 122 and the radial section 118 of the moveable portion 116. Further, rather being held in place by the fasteners 121, the rods 120 are allowed to move freely through the apertures formed in the flange 122.

[0189] As such, when the sealing faces 113, 114 are brought together (as shown in FIG. 6B), the force moves the moveable portion 116 towards the flange 122 against the biasing force of the spring 124 (i.e. until the force of the spring 124 matches that bringing the sealing faces 113, 114 together). The force of the spring 124 helps to increase the sealing force between the sealing faces 113, 114. As should be appreciated, the inflatable sealing member 115′ of FIG. 5 could be used in this arrangement.

[0190] The embodiment shown in FIGS. 7A and 7B differs from the above described arrangements in that it comprises circumferential, rather than planar, sealing faces 113, 114. In this embodiment, the distal end of the fluid exchange port 112 is received (as shown in FIG. 7B) within the interior of the opening 111 of the duct 106, so as to be surrounded by the opening 111 of the duct 106. A deformable sealing member 115′″, in the form of a piston seal, is mounted to the cell sealing surface 113 so as to extend circumferentially about the sealing surface 113. The sealing member 115″ comprises a plurality of radially extending and axially spaced ribs 125 that extend across the gap formed between the sealing faces 113, 114. Each rib 125 is inclined from the radial direction so as to extend slightly rearwardly (away from the distal end of the port 112). This facilitates receipt of the distal end of the port 112 into the duct opening 111. Receipt is also facilitated by a tapered entrance to the opening 111. In a variation of this embodiment, the piston seal may be inflatable (similar to that shown in FIG. 5.

[0191] When a module 108 or cell 101 is detached from the base structure 102, it may be desirable to close or cover the opening 111 to the duct 106 to prevent the ingress of water into the duct 106 (and to allow continued operation of the system 100). FIGS. 8-9 provide exemplary embodiments of blanking devices for performing this function.

[0192] In FIG. 8, the opening 111 is closed by a cap 126. This figure is a top view of the cap 126 and duct 106. Whilst not immediately apparent from the figure, the cap 126 is fitted onto the duct opening 111 by sliding it downwardly over the opening 111. The cap 126 comprises a retaining lip 127 that extends partway about the periphery of the cap 126 (so as to allow sliding of the cap over the opening 111). The retaining lip 127 comprises a radially inwardly projecting rim 128 that engages a flange 129 of the opening 111 so as to retain the cap 126 on the opening 111. An inflatable sealing member 115′ is disposed on an inner sealing face 113′ of the cap so as to be sandwiched between the cap sealing face 113′ and a planar duct sealing face 114 when the cap is in the engaged position. Inflation of the sealing member 115′ causes it to fill any gap between the sealing faces 113′, 114 and also moves the rim 128 of the retaining lip 127 against the flange 129.

[0193] In FIG. 9, a further embodiment is shown in which a plug 130, instead of a cap, is used to close the opening 111 to the duct 106. The plug 130 is cup-shaped so as to have a circular base 131 and a sidewall 131 (in the form of a tube) projecting from the base 131. An outer circumferential surface of the sidewall 131 defines a plug sealing surface 113″ that faces an inner circumferential sealing surface 114 of the duct opening 111. A sealing member 115′ is mounted to the plug sealing surface 113″ for sealing with the duct sealing surface 114. The sealing member 115″ is substantially the same as that shown in FIGS. 7A and 7B. Once the plug 130 is inserted into the opening 111 it relies on friction between the sealing member 115″ and the duct sealing surface 114, and any pressure difference (between the fluid flow path 103 and the external environment), in order to be retained in the opening 111.

[0194] FIG. 10 also illustrates a plug, which in this case is in the form of an inflatable sealing member 115″. This sealing member 115″ is configured such that, when in an inflated configuration, it extends across the entire opening 111 so as to block the opening and prevent water ingress into the fluid flow path 103 (or the escape of fluid from the fluid flow path 103).

[0195] Even with the provision of seals, caps and plugs, there is still the possibility of the ingress of unwanted fluid (such as water) into each cell 101 of the system 100. FIGS. 11 and 12 illustrate two arrangements that may facilitate removal of this fluid from a cell 101.

[0196] In FIG. 11, the cell 101 comprises a sump 132 that is fluidly connected to a low-point of the chamber 134 defined by the membrane 107 and the cell body 133 of the cell 101 (the sump 132 may alternatively be disposed at the low-point of the chamber 134). This means that water in the chamber 134 will flow to, and be collected in, the sump 132. The sump 134 may comprise a pump for discharge of the water from the system 100. It's worth noting that in the illustrated embodiment, the cell 101 comprises two fluid exchange ports in the form of an inlet 112a and an outlet 112b.

[0197] The embodiment of FIG. 12 differs in that it does not comprise a sump. Rather, the outlet 112b of the cell 101 is fluidly connected to the chamber 134 at the low-point of the chamber 134. Thus, any water in the chamber 134 will flow from the chamber 134 via the outlet 112b to the fluid flow path 103. The duct 106 defining the fluid flow path 103 may be provided with a pump for discharging water from the fluid flow path 103. In this way, (and unlike the embodiment of FIG. 11) only one pump may be required to discharge the water received from all of the cells 101 of the system 100.

[0198] A further issue that may be faced by the WEC system 100 is debris that enters the fluid flow path 103, which may reduce the efficiency of the system 100 and/or may cause damage to various components of the system (such as the turbine 105). FIGS. 13 to 14 provide exemplary arrangements for managing debris in the WEC system.

[0199] FIG. 13 illustrates a portion of the duct 106 of the system 100 that comprises the turbine 105. The duct 106 comprises a debris separator that is upstream of the turbine 105. The debris separator comprises a grille 135 that extends across the interior of the duct 106 and a debris trap 136 in the form of a recess positioned upstream of the grille 135. The grille 135, trap 136 and turbine 105 are disposed in a substantially horizontal portion of the duct 106. The grille 135 extends on an incline across the duct 106 such that a lower end of the grille 135 is further downstream than an upper end of the grille 135. The result of this arrangement is that the grille 135 partially overhangs the debris trap 136. Thus, debris that is blocked by the grilled 135 may fall (due to gravity) into the debris trap 136.

[0200] The embodiments in FIG. 14 also includes a grille 135′ and a debris trap 136′. Again, both the grille 135′ and the debris trap 136′ are upstream of the turbine 105. In this embodiment, however, the grille 135′ is disposed in a vertical portion of the duct 106 and extends substantially horizontally across the interior of the duct 106. The debris trap 136′ is located directly below the grille 135′ such that debris that is caught by the grille 135′ falls into the debris trap 136′.

[0201] In FIG. 15, the embodiment comprises a centrifugal separator 137 instead of a grille. The centrifugal separator 137 is oriented vertically and disposed in a vertical portion of the duct 106. As should be appreciated, the centrifugal separator 137 is configured such that working fluid passes through an upper outlet thereof (so as to continue flowing through the duct 106), whilst debris is discharged through a lower opening of the centrifugal separator 137 (into a debris trap 135″).

[0202] FIGS. 16A and 16B illustrate engagement of a cell 101 with a base structure 102 according to a first embodiment. The cell 101 and base structure 102 are illustrated schematically and thus, for example, the fluid flow path or duct of the base structure 102 are not shown (nor is the fluid connection between the cell 101 and the base structure 102).

[0203] The cell 101 comprises a first mounting portion 138a, which is in the form of a substantially horizontally extending pin and is located at an upper end of the cell 101. The cell 101 also comprises a second mounting portion 138b positioned at a lower end of the cell 101 and connected to the cell 101 by an actuator in the form of a hydraulic ram 139. A proximal (upper) end of the ram 139 is mounted to a central portion of the underside of the cell 101 and an opposing distal end of the ram 139 forms the second mounting portion 138b, which is also in the form of a horizontally extending pin.

[0204] The base structure 102 comprises, at an upper end thereof, a first receiving portion 140a, which is hook-shaped and defines a hook-shaped first recess 141a into which the first mounting portion 138a of the cell 101 may be received. The base structure 102 also comprises a second receiving portion 140b that defines a second recess for receipt of the second mounting portion 138b of the cell 101. The first receiving portion 140a is positioned so as to be above and rearward (i.e. away from the cell 101) with respect to the second receiving portion 140b.

[0205] As is illustrated by FIG. 16B in particular, to mount the cell 101 to the base structure 102, the cell 101 is moved such that the first mounting portion 138a is received in the hook-shaped recess 141a. The hook shape of the first receiving portion 140a aids in guiding the first mounting portion 138a into the recess 141a. That is, a lower projection 142 of the hook-shape extends in a forward direction (towards the cell 101) in an inclined manner, such once the first mounting portion 140a is received on an upper surface of the projection 142, the incline of the projection 142 means that the first mounting portion 140a will be guided (e.g. by the projection 142 and gravity) further into the recess 141a.

[0206] Once the first mounting portion 138a is received in the hook-shaped recess 141a, the cell 101 is further moved (e.g. lowered) such that the second mounting portion 138b is proximate the second recess 141b (of the second receiving portion 140b). The hydraulic ram 139 is then extended so as to move the second mounting portion 138b into the second recess 141b. Further extension of the hydraulic ram 139 causes the second mounting portion 138b to contact an end of the second recess 141b and continued extension from this point causes the cell 101 to move away from the second mounting portion 138b and the second receiving portion 140b. When this occurs, the first mounting portion 138a moves further into the hook-shaped recess 141a. Due to the hook shape of the recess 141a, an end of the recess 141a defines a locking region 143 that restricts movement of the first mounting portion 138a out of the recess 141a.

[0207] Thus, once the first mounting portion 138a is received in the locking region 143 the cell 101 is locked (i.e. fully mounted) to the base structure 102.

[0208] The embodiment of FIGS. 17A and 17B is similar to that described above and therefore corresponding reference numerals have been used. This embodiment differs, however, in that the second mounting portion 138b is disposed at a distal end of an over-centre mechanism 144 for locking the second mounting portion 138b in position. The over-centre mechanism 144 comprises first 145a and second 145b linkages that are connected to one another at a central pivot point 146. The first linkage 145a is coupled at a proximal end (proximate the cell 101) to a coupling plate 147 projecting downwardly from an underside of the cell 101. The second mounting portion 138b is mounted at a distal end (distal from the cell 101) of the second linkage 145b. A hydraulic ram 139 is coupled, at one end, to the coupling plate 147 and at the end to the central pivot point 146 of the linkages 145a, 145b.

[0209] The operation of the over-centre mechanism 144 is apparent from FIG. 17B in particular. As the hydraulic ram 139 is extended, the second linkage 145b is moved such that the second mounting portion 138b is moved into the second recess 141b. Further extension of the ram 139 results in the linkages 145a, 145b becoming parallel and then subsequently will pivot so as to be “over-centre” (as shown in FIG. 17B). The over-centre mechanism 144 may, for example, be provided with a stop in order to limit further extension of the ram 139 (i.e. beyond the over-centre position). The over-centre position thus represents a stabled locked position so as to maintain the cell 101 in a mounted state with the base structure 102.

[0210] In FIG. 18, the cell 101 again comprises first 138a and second 138b mounting portions. These are, however, in the form of apertures rather than pins (as was the case with the previously described embodiments). The base structure 102 comprises corresponding first 140a and second 140b receiving portions in the form of vertically extending tapered pins. The tapered shape of the pins facilitates engagement of the receiving portions 140a, 140b with the mounting portions 138a, 138b. In a variation of this embodiment, the pins may be provided on the cell 101 and apertures (for receipt of the pins) may be provided on the base structure 102.

[0211] In FIG. 19, the cell 101 comprises a ballast weight 148 that has sufficient mass to secure the cell 101 with respect to the base structure 102. The ballast weight 148 comprises a recess 149 formed in an underside thereof. The recess 149 engages a corresponding protrusion 150 of the base structure to further facilitate the restriction of movement of the cell 101 relative to the base structure 102.

[0212] In the embodiments discussed above, the module 108 comprises one or more cells 101, each having a cell body 133 that, along with a membrane 107 defines a chamber 134 for storing a working fluid. An alternative arrangement to this is depicted in FIGS. 20 and 21.

[0213] As is apparent from FIG. 20, in this system 200 the module 208 (i.e. the modular part of the system 200) comprises a membrane 207 and a support frame 251, across which the membrane 207 is stretched. The support frame 251 is formed of an aperture tube 252 that extends in an obround shape and defines an obround aperture across which the membrane 207 is stretched, an inner skirt 253 depending from an inner (aperture-facing) side of the aperture tube 252, and an outer skirt 254 depending from an opposing outer side of the aperture tube 253. A base plate 255 extends transversely between the inner 253 and outer 254 skirts and, as will be explained further below, a lower surface of the base plate 255 defines a sealing surface 213 of the module 208. The support frame 251 may be formed of steel and the components of the support frame 251 may be welded together to form the support frame 251.

[0214] An outer edge of the membrane 207 is clamped to a lower edge the outer skirt 254 by way of a plurality of clamps 256 that are spaced about the support frame 251.

[0215] The module 208 is configured to engage with a cell body 233 that may form part of a base structure (not shown). The cell body 233 may be formed of e.g. steel or concrete and comprises a recess 257 that, together with the membrane 207, defines a chamber for working fluid (when the module 208 is mounted to the cell body 233).

[0216] To facilitate the mounting, module 208 comprises mounting portions in the form of a plurality of locks 258 that are spaced along the base plate 255 of the support frame 251. Each lock 258 may, for example, be in the form of a twist lock that can be rotated in and out of a locked position. The cell body 233 comprises receiving portions in the form of a plurality of locking holes 259 formed therein that are each arranged for receipt of a corresponding lock 258 of the module 208. Thus, to mount the module 208 to the cell body 233, the module 208 can be manoeuvred such that the locks 258 are received in the locking holes 259. The locks 258 can then be actuated so as to enter a locked position, in which the module 208 is retained with respect to the cell body 233.

[0217] The module 208 further comprise inner 260 and outer 261 sealing members that extend along the sealing surface 213 such that each forms a complete loop. When the module 208 is mounted to the cell body 233, the sealing members 260, 261 are sandwiched between the base plate 255 and the cell body 233. This seals between the chamber (formed between the cell body 233 and the membrane 207) and the external environment.

[0218] FIGS. 22A and 22B depict a further module 108′ that is of the type discussed above with respect to FIGS. 1 to 19. The module 108′ comprises a cell body 133 shaped so as to form a chamber 134 and an aperture that may be sealed by a membrane (not shown). The module 108′ comprises an (upper) inlet fluid exchange port 112a and a (lower) outlet fluid exchange port 112b to provide a sealed fluid connection between the chamber and a fluid flow path of a WEC system.

[0219] The module 108′ additionally comprises a handling frame 162 that provides a connection point for a handling tool, which in the present case is in the form of a winch 163. The handling frame 162 comprises two laterally spaced U-shaped frame elements 164 that are connected by a transversely extending cross-beam 165. Each frame element 164 extends from a connection at an upper lip of the cell body 133 to an opposing connection at a lower lip of the cell body 133. A central portion of each frame element 164 is spaced above the cell body 133 so as to provide for attachment of the winch 163. The handling frame 162 provides an additional function in that it acts to limit expansion of the membrane (not shown), which may avoid damage to the membrane.

[0220] Deployment of the module 108′ shown in FIGS. 22A and 22B is illustrated in FIGS. 23A to 23H.

[0221] FIG. 23A shows the module 108′ suspended from a buoyancy tool in the form of a deployment barge 166. In particular, the module 108′ is suspended from a winch (not shown) that is mounted to a gantry 169 of the barge 166. The combination of the winch and the gantry 169 provides manoeuvrability of the module 108′ by the barge 166 along three axes.

[0222] The deployment barge 166 is being towed by a towing vessel 167. The barge 166 is formed of four elongate hull portions 168a, 168b, 168c, 168d forming a rectangular shape so as to define a rectangular aperture therebetween. The shape of the barge 166 (i.e. the provision of the four elongate hulls 168a, 168b, 168c, 168d) is such that it has a reduced water plane area compared to the towing vessel 167. As such, the barge 166 has a dynamic response in waves that is less than that of the vessel 167. This reduces the differential movement between the lifting points and the module 108′, which reduces dynamic winch cable loads.

[0223] In FIG. 23B, the barge 166 is located at the site of the base structure 102, to which the module 108′ is to be mounted. The base structure 102 is positioned on the seabed below the barge 166, which is floating on the sea surface. The barge 166 is connected to four spaced apart mooring points (not shown) via mooring lines 170. Each mooring line 170 extends from a corresponding mooring winch 171 mounted to the barge 166. In particular, each hull intersection comprises a mooring winch 171 such that the four mooring winches 171 are mounted at the corners of the barge 166. The winches 171 are then controlled to move the barge 166 into the desired position above the base structure 102.

[0224] In FIG. 23C, the module 108′ has been lowered to the base structure 102 by the winch (not shown). As is shown in more detail in FIG. 23, the module 108′ has been manoeuvred (by movement of the winch on the gantry 169 of the barge 166) such that a first mounting portion 138a (in the form of a pin) at an upper rearward portion of the module 108′ is received in the recess 141a of a first receiving portion 140a of the base structure 102. This receipt is facilitated by a lower projection of the first receiving portion 140a, which defines an inclined guide surface 142 to guide the first mounting portion 138a into the recess 141a.

[0225] In FIG. 23D, the module 108′ has been lowered further by the winch. Due to the location of the first mounting portion 138a in the recess 141a of the first receiving portion 140a, the module 108′ has pivoted about that first mounting portion 138a. One result of this pivoting is that a second mounting portion 138b at a forward lower portion of the module 108′ is brought in proximity to a second receiving portion 140b of the base structure 102. Another consequence is that an electrical connector of the module 108′ (not shown) comes into contact with a wet mate connector (not shown) of the base structure 108′ such that an electrical power supply is provided to the module 108′. This connection also provides an indication that the module 108′ is seated on the base structure 102. Additional sensors may also be used to provide such an indication.

[0226] Additionally, the fluid exchange ports 112a, 112b of the module 108′ are brought into engagement with the duct openings 111a, 111b of a duct of the base structure 102 defining a fluid flow path (i.e. to a turbine of the base structure 102).

[0227] In FIG. 23F, subsequent to electrical power being supplied to the module 108′, a hydraulic ram 139 of the module 108′ is activated so as to be caused to move from a retracted position to an extended position. The second mounting portion 138b is mounted to a distal end of the hydraulic ram 139 such that, upon extension of the hydraulic ram 139, the second mounting portion 138b is moved into engagement with the second receiving portion 140b (as shown in FIG. 23H). Further movement of the ram 139, subsequent to this engagement, results in movement of the module 108′ in a rearward and upward direction as guided by the first mounting portion 138a in the recess 141a of the first receiving portion 140a. This causes the first mounting portion 138a to enter a locking region 143 of the recess 141a (as shown in FIG. 23G). The locking region 143 extends in an upward and rearward direction from the entrance of the recess 141a such that, upon location in the locking region 143, the first mounting portion 138a is prevented from moving laterally out of the recess 141a. In this way, the module 108′ is secured to the base structure 102, and a sealed fluid connection is provided between the chamber of the module 108′ and the duct of the base structure 102.

[0228] The winch may subsequently be disengaged from the module 108′ and retracted so as to complete deployment of the module 108′. A membrane may then be secured to the module 108′ (if not already secured thereto) and the chamber 134 of the module can be purged of any water located therein. As should be appreciated, the process may be reversed in order to remove the module 108′ from the base structure 102.

[0229] FIGS. 24A and 24B illustrate a further embodiment of a WEC system 300 that is configured such that a membrane 307 of the system lies in a substantially horizontal plane in normal use (although it should be appreciated that the membrane could lie on a slope with modification). This system 300 is similar to that shown in FIG. 20 in that module 308 comprises a support frame 351 and a working surface in the form of a membrane 307 but does not include a cell body 333. Instead, the cell body 333 forms part of a fixed structure that, in this embodiment, may be fixed to the seabed.

[0230] The profile of the cell body 333 is most apparent from FIG. 24A. The cell body 333 comprises a convex surface that defines a recess 357. This recess 357, together with the membrane 307, forms a chamber in which a working fluid may be stored in normal use. A peripheral lip 363 of the cell body 333 extends about (so as to surround) the recess 357. An inner circumferential surface 364 of the peripheral lip 363 partly defines the chamber and forms part of the convex surface defining the recess 357. An outer circumferential surface 367 of the peripheral lip 363 slopes downwardly and outwardly from an apex of the lip 363. Thus, the peripheral lip 363 tapers outwardly in a downward (or rearward) direction (i.e. in a direction of receipt of the module 308 in use).

[0231] The support frame 351, which is shown alone in FIG. 24B, comprises a ring member in the form of an aperture tube 352, which defines an aperture of the support frame 351 across which the membrane 307 extends (and seals in use). Although the aperture tube 352 has a tubular shape, it should be appreciated that it may take other forms that are not necessarily tubular.

[0232] A skirt 353 (which may be considered an inner skirt) depends from the aperture tube 352 (i.e. and extends for the entire circumference of the aperture tube). In particular, the skirt 353 is sloped in an inwardly and downwardly/rearwardly direction (i.e. in normal use). In this way, an internal space defined by the skirt 353 has an inverted frustoconical shape. The shape of the skirt 353 is such that it forms a generally continuous surface with the inner circumferential surface 364 of the cell body 333 (when the support frame 351 is mounted thereto). In this way, the skirt 353 partly defines the chamber for holding the working fluid.

[0233] A base member in the form of a base plate 355 projects outwardly from a lower end of the skirt 353 (i.e. for the entire circumference of the skirt). A lower surface of the base plate 355 defines a sealing surface 313 of the module 308. The base plate 355 rests on the peripheral lip 363 of the cell body 308 via a deformable sealing member 360 that is received between the base plate 355 and the peripheral lip 363. This provides the sealed connection between the module 308 and the cell body 333 (i.e. the sealing member 360 prevents leakage of fluid from (or into) the chamber). Thus, the portion of the interface between the cell body 333 and the support frame 351 located within the peripheral deformably sealing member 360 is sealed from water and, likewise, leakage of working fluid via the interface is prevented.

[0234] The support frame 351 also comprises a guide portion, which in the present embodiment is in the form of a plurality of webs 365 (or plates) depending from both the aperture tube 352 and the skirt 353. The webs 365 are spaced about the circumference of the support frame 351. Each web 365 comprises an inner edge 366 that is sloped outwardly and downwardly/rearwardly. The slope of the inner edge 366 is such that it complements the outer circumferential surface 367 of the peripheral lip 363. In this way, as the module 308 is lowered onto the cell body 333, the inner edges 366 of the webs 365 engage the outer circumferential surface 367 so as to guide the module 308 onto the cell body 333.

[0235] In addition to providing this guiding function, each web 365 also comprises a working surface retaining portion in the form of a notch 368. This notch 368 provides an attachment point for a corresponding mounting portion 369 of the membrane 307. That is, the membrane mounting portions 369 hook into each notch 368 so as to retain the membrane on the support frame 351. In particular, and as is illustrated, the membrane 307 extends over the curved circumferential outer surface of the aperture tube 352 and extends in a downward/rearward direction (where it is then connected to the support frame 351 by way of the mounting portion 369).

[0236] The support frame 351 also provides means for securing the module 308 to the cell body 333. In the present embodiment, that is in the form of a lower circumferential member 370 that extends about a periphery of the support frame 351 at lower ends of the webs 365. This lower circumferential member 370 comprises a plurality of circumferentially spaced apertures for receipt of hook member 371. Although not illustrated, these hook members engage with a corresponding circumferential portion of the cell body 333 to retain the module 308 on the cell body 333. As should be appreciated, other securing means may be used to secure the module 308 to the cell body 333, such as selective locking means. In other embodiments, for example, the mounting portion 369 of the membrane 307 may be secured to the cell body 333 once the support frame 351 is received on the cell body 333 (e.g. the mounting portion 369 may be disconnected from the support frame 351 and then reconnected on the cell body 333). In this way, the membrane 307 itself would retain the support frame 351 on the cell body 333.

[0237] FIGS. 25A and 25B illustrate a portable installation device 472 for installing a membrane 407 on a submerged cell body 433. The installation device 472 comprises a body 473 defining a cavity 474 having an opening, and a plurality of mounting portions 475 at a periphery of the opening of the cavity 474. The device mounting portions 475 are configured for releasable engagement with corresponding mounting portions 469 of the membrane 407. In this way, as is shown in FIG. 25A, the membrane 407 can be secured along the periphery of the opening so as to seal the opening of the cavity 474. The body 473 further comprises two outlets 477 that are each fluidly connected to a respective riser 478 downstream of the outlet 477.

[0238] The installation device 472 is configured to draw the membrane 407 into the cavity 474 to facilitate mounting of the membrane 407 to the cell body 433. This configuration is shown in FIG. 25B. In this figure, the installation device 472 has been lowered to the submerged cell body 433 such that it is also submerged (i.e. below the free surface 479 of a body of water). As a result, the pressure external to the installation device 472 has increased (i.e. is above atmospheric). However, the pressure in the cavity 474 remains the same during this lowering, because the risers 478 maintain fluid communication between the cavity 474 and the atmosphere. The result of this is that the pressure of the fluid in the cavity 474 is less than that externally of the cavity 474 and the membrane 407 is thus drawn into the cavity 474.

[0239] In the present embodiment, because the risers 478 remain open, as the installation device 472 is lowered, the membrane 407 is gradually drawn into the cavity 474 (due to the gradual increase in pressure differential). In other embodiments, the risers 478 may comprise a closure (e.g. cap, bung, valve, etc.) which may be opened once the installation device 472 has been lowered to the cell body 433 (i.e. providing more rapid drawing in of the membrane 407).

[0240] Accordingly, the membrane 407 is moved into a position that makes it easier to mount it onto the cell body 433. In particular, in this position the membrane 407 can be received over and around a peripheral lip 463 of the cell body 433. The membrane 407 can then be disconnected from the installation device 472 and subsequently connected to the cell body 433 by engagement of the membrane mounting portions 469 with corresponding membrane retaining portions 468 of the cell body 433.

[0241] FIGS. 26A to 26D schematically illustrate further WEC module embodiments. Each of these embodiments includes similar features, and for that reason the same reference numerals have been used to designate the same features. Each module includes a membrane 507 extending across an aperture defined by support frame 551, which forms part of a cell body 533. Together, the cell body 533 and membrane 507 define a chamber 534 for a working fluid (such as air). Each module can be mounted to a base structure via mounting portions 558 provided on the support frame 551.

[0242] FIG. 26A illustrates an embodiment in which the module 508 includes a single fluid exchange port 512 in the form of an aperture formed in the cell body. The fluid exchange port 512 is configured for fluid flow both into and out of the chamber 534.

[0243] The module includes inner 560 and outer 561 peripheral deformable sealing members disposed on the support frame 551. The sealing members 560, 561 extend for the entire periphery of the support frame 551 so as to seal the module 508 to a base structure when mounted thereto. In particular, the sealing members 560, 561 prevent leakage of working fluid from the chamber 534.

[0244] In FIG. 26B, the module 508′ comprises two fluid exchange ports 512. Each fluid exchange port 512 may be configured for one-way flow of fluid therethrough (e.g. may comprise a one-way valve). Alternatively, both fluid exchange ports 512 may permit fluid flow in both directions.

[0245] In this embodiment, the module 508′ includes two sealing members 560, 561 that each extend about a respective fluid exchange port 512. By doing so, the sealing members 560, 561 seal the fluid exchange ports 512 and prevent leakage of working fluid from the chamber 534.

[0246] In FIG. 26C, the module 508″ again includes two fluid exchange ports 512, but instead of having two deformable sealing members, a single sealing member 560 extends about both fluid exchange ports 512.

[0247] In FIG. 26D, the module 508′″ the cell body 533 is formed of a mesh so as to comprise a plurality of closely spaced fluid exchange ports 512. A single peripheral sealing member 560 is provided on the support frame 551. In this embodiment a pump may be required as part of the base structure to discharge any water held in the cell body 533.

[0248] The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

[0249] While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

[0250] For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations.

[0251] Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0252] Throughout this specification, including the claims which follow, unless the context requires otherwise, the words “have”, “comprise”, and “include”, and variations such as “having”, “comprises”, “comprising”, and “including” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0253] It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment. The term “about” in relation to a numerical value is optional and means, for example, +/−10%.

[0254] The words “preferred” and “preferably” are used herein refer to embodiments of the invention that may provide certain benefits under some circumstances. It is to be appreciated, however, that other embodiments may also be preferred under the same or different circumstances. The recitation of one or more preferred embodiments therefore does not mean or imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the disclosure, or from the scope of the claims.