A double suction impeller is disclosed. In at least one embodiment, the impeller is configured for centrifugal pumps and hydraulic power recovery turbines. The impeller's flow-path arrangement comprises inter-blade channels, intersecting each other at the impeller's outer diameter and defining a variable cross section shape, so that the equivalent number of blades is at least doubled with respect to a conventional configuration obtained by the coupling of two single suction impellers and an improved control over the velocity of the flow within the inter-blade channels is achieved.

A water-driven turbine has an elongated endless conveyor with down and up streaming straightaways connected by travel-reversing turns. Paddles mounted on the conveyor present high resistance to waterflow on the downstream straightaway and low resistance to waterflow or the atmosphere on the upstream straightaway, the differential allowing the flow of water to continuously drive the conveyor which is connected to a power take-off shaft facilitating connection to a variety of energy-harnessing systems. The turbine can be towed, self-driven or mooring line manipulated to a flow site and is operable in unidirectional flows such as rivers and reversing flows such as tides at depths from surface to bottom. The paddles can be mounted or changed on shore, at the flow site and anywhere in between. The turbine is efficient in low and high velocity water flow, not easily damaged by floating debris, cavitation free and fish, mammal and environmentally friendly.

An adjustable multi-functional bottom-hinged flap-type wave energy utilization device includes at least three wave energy conversion devices arranged in parallel and with adjustable spacing. Each wave energy conversion device includes a wave energy conversion component, a direction adjustment component for adjusting a wave-facing direction of the wave energy conversion component, and a height adjustment component for adjusting a height of the wave energy conversion component. The wave energy conversion component includes a mounting base plate, a transmission shaft arranged on the mounting base plate, a wave energy flap that can drive the transmission shaft to rotate, a generator connected to the transmission shaft, a hydraulic oil cylinder positioned on a back surface of the flap for pushing the flap to reset, and a wave monitor arranged on the mounting base plate for monitoring a draught and a wave direction angle of the flap.

A subterranean energy storage system configured to store and subsequently release potential energy. Storage of potential energy is achieved by the transfer of a pseudo fluid from a first storage tank to a second storage tank located above the first storage tank, and is subsequently released by the transfer of the pseudo fluid from the second storage tank to the first storage tank. To transfer the pseudo fluid between the first and second storage tanks, the subterranean energy storage system comprises at least one continuous conveyor mechanism extending through at least one transport shaft, wherein the at least one continuous conveyor mechanism comprises a plurality of vessels arranged along a length of the continuous conveyor mechanism. The subterranean energy storage system further comprises an energy transfer means operably connected to the at least one continuous conveyor mechanism to transfer power to and from the subterranean energy storage system.

A reactive blade turbine system works vertically, horizontally, or at an angle and clockwise or counterclockwise according to blade angle and locking position and adjusts to variations in fluid flow such as changes in tidal currents to generate power more efficiently regardless of direction of fluid flow.

A system for energy storage and electricity generation is described. The system includes an energy storage system providing compressed air and an electricity generation system. The electricity generation system includes an airlift pumping system pneumatically coupled to the energy storage system. The airlift pumping system includes a water collecting tank containing collecting water and a riser tube having a base immersed in the collecting water and configured for injection of the compressed air into the riser tube through the air pipeline to provide air bubbles within the riser tube that produce an upward flow of the collecting water together with the air bubbles. The electricity generation system also includes a hydro-electric power system driven by upward flow of the collecting water together with the air bubbles to produce electricity, and a water heating system for heating the collecting water in the water collecting tank.

The present invention relates to non-thermal renewable energy turbines (20,24,34, 38,40), in particular to the monitoring of turbine performance to identify a loss of performance indicative of faults or component degradation. The method involves comparison of measured power from a target turbine (20) with a predicted value for same turbine. The predicted value is calculated using the output from a plurality of other turbines (24,34,38,40) from an array and a predictive model including weightings for the other turbines (24, 34,38,40) based on the strength of correlation of their historical with historical data from the target turbine (20).

The present invention provides a turbine sub-runner that is positioned to be within the vortex zone of a turbine wicket gates (zone “S—R”, FIG. 1). The sub-runner includes at least two sub-runner blades, configured to monitor the relative flow of the vortex created by the wicket gates. A control mechanism is connected to the sub-runner shaft via gear and threaded interface, and is capable of transferring the relative (vs main-runner) rotational energy of the sub-runner into angular movement of the main runner blades. As the sub-runner interacts with the changing conditions of the main vortex within the zone “S—R”, it will act to automatically regulate, adjust, and control the angle of the main runner blades to optimize the performance of the turbine. The sub-runner uses the energy of the vortex existing in the zone “S—R” to perform the monitoring, regulation, adjustment and control of the main runner through regulating angular position of main runner blades.

The present disclosure relates to a construction method for a deformable anchor cable capable of being prestressed. The anchor cable includes an outer sleeve, a shrinkage pipe, an inner sleeve, a steel strand, an anchor and a tray. When the anchor cable is in use, a hole is drilled first, then the anchor cable is mounted in the drilled hole, and finally a prestress is applied to the steel strand of the anchor cable. According to the construction method, the construction is convenient; the anchor cable has the characteristics of high strength and large deformation, and can be easily prestressed; and the large deformation is realized by squeezing the inner sleeve by means of the anchor, which completely overcomes the problem of breaking a cold-drawn rod during the large deformation process.

The invention concerns a method for starting a hydroelectric turbine (10) in a pumping mode, said turbine being provided with a runner (6) mechanically coupled to a shaft line (8) and a variable speed electric motor connected to a grid, a distributor (4) comprising guide vanes to control a flow of water to said runner, the method comprising: a) a step of operating the variable speed motor at least partly at fixed speed, said guide vanes being only partially opened, and of defining or calculating: data of a plurality of hydraulic characteristics (C.sub.1, C.sub.2, C.sub.i) of the turbine for an operation without cavitation; data of an operation range of the electric motor, giving the speed of the motor as a function of its power; b) then a step of operating the turbine in a power control mode.