Subsea actuators and gearboxes assist first-of-kind commercial wave energy project
Rotork Australia has supplied subsea rack and pinion hydraulic valve actuators and subsea gearboxes for an innovative renewable energy wave technology project on Garden Island, near Perth in Western Australia.
The patented CETO (Carnegie Wave Energy) technology converts ocean swells into a source of energy for power generation and water desalination plants. Unlike other wave technology systems, the CETO wave power converter is fully submerged and produces high pressure water from the power of waves. A submerged buoy moving up and down with the movement of the waves drives a pump attached to the seabed. The pump in turn delivers water ashore through a pipeline at high pressure that enables zero-emission electricity or fresh water to be produced.
Due for completion early in 2014, the Perth Wave Energy Project will be the first demonstration of a complete grid-connected, commercial scale CETO power generation system anywhere in the world.
Rotork actuators and gearboxes have been ordered by Severn Glocon Australia and include double-acting hydraulic actuators equipped with top-mounted diver operated override gearboxes, controlling subsea ball valves installed at a depth of 25 metres. The override gearbox incorporates a ‘lost quadrant’ system in the gear pinion, providing a simple but highly effective mechanism for switching between hydraulic and manual operation. All the diver has to do is rotate the handwheel to the three positions – remote (hydraulic), open (manual) or close (manual) – which are visible through the indicator on top of the gearbox. Co-operation between Rotork Fluid Systems and Rotork Gears has enabled a rugged, compact, well engineered and cost-effective solution to be delivered for this application.