GB2245031A - Wave power resonance generator - Google Patents

Abstract

A surge of sea water through a guide channel is used to force a column of sea water up inside a chamber in a similar way to a piston in a cylinder. The column of water drives air through a turbine into a second sealed chamber where the air becomes compressed. This compressed air returns through the turbine as the water column falls. The system is tuned (e.g. by varying the capacity of the sealed chamber or the air pressure therein) to resonate with the frequency of sea surges to obtain maximum power conversion efficiency. The turbine may drive an electric generator or an hydraulic pump and the device may be built into a cliff face or installed on a ship. It may be associated with a desalinating plant. <IMAGE>

Description

WAVE POWER RESONANCE GENERATOR This invention relates to the use of energy in sea waves and sea swell to drive electrical generators, and hydraulic pumps.

Attempts to make practical use of wave energy have accelerated since about 1970. This is due to concern about emissions from conventional power stations, and to doubts about the economic efficiency and acceptability of atomic power stations. Recently, the green house effect and the shortage of fresh water in many areas have speeded up the search for pollution free energy sources.

The phenomena of resonance is well known, and attempts have been made to utilise it in industry, such as in deep well pumps in the USSR.

Conversely, the destructive power created in machines which vibrate at resonant frequency due to a relatively small disturbing force is something which often needs to be designed out. Examples include bridges and automatic control systems.

Several devices have been constructed using an oscillating column of water to drive air through a turbo generator, notably in Norway, Japan and in the Islay Project.

It is a feature of this invention that the power conversion efficiency will be optimised by having the whole system in a state of resonance instead of only the water column.

In this invention, which is illustrated schematically in Figure 1, a sealed chamber receives the exhaust air from a turbine while the water column is rising. This air becomes compressed and stores energy from the sea, which is available to boost the return stroke when the water column is falling. By matching the differential volume of the water column to the volume of the sealed chamber and the incoming sea frequency, the system will resonate and power surges will occur.

Some tuning could be obtained by varying the capacity or the air pressure in the sealed chamber. Damping would be a function of friction and turbine output.

In Figure 1 an example is shown of a roller shaped turbine with integral generator. This requires rectifying flap valves which would operate satisfactorily because the frequency of operation will be low. Alternatively, a wells turbine could be used. It is considered that the roller shaped turbine would make more efficient use of the width of water channel available.

Claims (7)

1A device for obtaining power from the sea in which a rising column of water in a chamber displaces the air in the chamber through a turbine into a second sealed chamber.

The second chamber becomes pressurised by the turbine exhaust, and the stored energy is available to boost the return stroke through the turbine as the sea falls. By tuning the system into resonance, power surges will occur and power conversion efficiency will be optimised.

2 A device for obtaining power from the sea as in Claim 1 which can drive an integral or external generator.

3 A device for obtaining power from the sea as in Claim 1 which can drive a hydraulic pump to supply a hydraulic accumulator in order to give a steady take off for an electrical generator.

4 A device for obtaining power from the sea as in Claims 1, 2 and 3 where the second chamber can be of low profile or built into a cliff face.

5 A device for obtaining power from the sea as in Claims 1, 2 and 3 which would operate on board a sea going ship.

6 A device for obtaining power from the sea as in Claims 1, 2, 3, 4, and 5 which does not require a steady output if used to supply a sea water desalinating plant to provide fresh water.

7 A device, as shown in Figure 1, and as in all previous claims which is pollution free.