At the present stage of civilization the need for renewables increases. In difference from many other types of energy (nuclear power, industrial power system and others), energy of sea tides doesn’t run dry as it is supported by gravitation forces of the Moon and the Sun and doesn’t depend on climate changes. The main problem of non-traditional renewables is the low density of energy. So the density of energy less than 1 kilowatt per square meters is typical for wind, solar, geothermal installations. Wave energy possesses the more high density of energy. Sea waves accumulate wind power on the considerable space of acceleration. There are favorable climatic conditions for development of wave power engineering on the coast of the Far East. Annual average potential of wave energy on the east coast is estimated approximately at 40 kilowatts per square meter [1, 59].
Our attention was attracted by wave power plants of Oyster. The wave energy installations containing a vertical platform (leaf) which consists of the floats hinged to the base lying at the bottom and the piston pump are known. Waves move a vertical platform which puts into action the power-take-off device in the form of the pump forcing water in the pipeline to the hydro turbine connected with the electric generator. The OWSC advantages (Oscillating wave surge converter) are small costs of construction, ecological purity, and high efficiency. Shortcomings of the OWSC: the effective usage only on large waves when there is an intensive swinging of leaf, the possibility of shift and corrupting of constructions by the storm waves [2, 22].
The first technical contradiction is formulated due to the shortcomings. The floats of the leaf can have insufficient buoyancy for creation of the recovering forces. Their rigidity is possible to regulate by tension or weakening. Small natural frequency of oscillations of the flaps causes that on short waves it swings far from resonance and insufficiently intensively. In this case it is necessary to increase significantly natural frequency of the system; however, it is technically difficult to make it only due to buoyancy increase. During using tide the leaf can be in deepening that reduces wave action, and in case of a low tide the leaf either sticking out significantly above water level, reducing the wave pressure area, or has inclined position from equilibrium that leads to reduction of dynamic pressure of waves to its surface. Even in the absence of essential tides the leaf has insufficient efficiency as when passing a wave trough it sticking out above from water, and when passing wave crest it is deepened. In both cases hydrodynamic pressure is less on the leaf, than on a wave surface. Besides, in some oscillating phases the wave crests can shock on the leaf sticking out above water. It is dangerous for durability. As a result reliability of the construction decreases. System itself provides the highest efficiency of wave’s energy conversion in different conditions [3, 139].
We have used 40 standard techniques of TRIZ and marked out the most suitable for our installation. Principle of dynamism – characteristics of object shall change so that to be optimum at each stage of operation (in roll forward and rollback of a wave); to divide object into the parts capable to move relatively each other. Principle of sampling action − natural frequency of system oscillations is to be changed with the change of wave’s parameters in order to get resonance with waves. The system of reactive forces controlling is necessary for this purpose. In the installation of OYSTER it can be done by controllable water filling or by air blowing of floats tanks. But it is too slowly. Principle of the continuity of the useful effect – all parts of object shall work with full loading at each phase of wave passing. The leaf slides along the guide frame, automatically falling and rising, tracing water level and waves profile by buoyancy forces [2, 119]. Improvement of wave converters goes on the way of receiving more controllable technical systems which according to the law of increasing vepol degree: have to more complex vepol (substance – field) model. Wave’s energy converters in the form of hinged arm rafts (Kokkerell’s raft, Pelamis) are known. They have rather low efficiency and at least 3-4 hinged float sets are required for it increasing. Besides there is a problem of devices fixing on anchors. It is offered to combine systems with a vertical flap and a horizontal raft for efficiency increasing of wave’s energy.