Prime-mover dynamo plants – Tide and wave motors
Patent
1993-11-02
1996-04-23
Stephan, Steven L.
Prime-mover dynamo plants
Tide and wave motors
290 42, 290 43, 290 54, F03B 1310, F03B 1300, F03B 1312, H02P 904
Patent
active
055106560
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a converter for transforming wave energy into electrical energy. The invention comprises several novel and inventive aspects but in particular, new forms of wave collector, a special rotor arrangement for driving a generator and method of anchoring the apparatus to the sea bed.
Since the 1970's there has been increasing concern about the earth's finite fossil fuel resource and about environmental polution resulting from combustion of such fuels. This has led to considerable efforts to develop new and cost-effective means of obtaining energy from renewable sources. In particular, there has been much interest in how to derive usable energy from solar, geothermal, wind and wave sources. The latter two offer the prospect of generating electricity by directly converting the kinetic energy of wind or waves into electrical energy.
Theoretically, waves constitute an enormous reservoir of energy to be exploited. However, their random nature and the hostility of the marine environment pose significant problems to the practical realisation of a cost-effective wave-to-electricity energy converter.
Although deep water offers the largest incident power flows, it has been realised that the mass, rigidity and complex engineering necessary to enable the equipment to survive in that environment makes it uneconomic. Another reason is that deep water structures must float and this reduces the conversion efficiency.
It is now known that depth of about 10 fathoms is about optimum. Although incident power flows reduce with decreasing depth, so do construction, installation and operating costs.
However, a viable design for a converter designed to operate at this depth has not been realised up to now.
We have now devised such a viable structure, which in accordance with a first aspect of the present invention, provides a wave collector comprising a substantially hollow annuloid shell having at least one opening for ingress of waves.
In use, the at least one opening is situated below the water so that waves entering through the opening impart their kinetic energy to the mass of air in the collector, above the water line.
In the context of this specification, the term "substantially hollow annuloid shell" is intended to refer to any closed substantially hollow structure which defines a substantially hollow core through the middle thereof. Thus, in radial cross-section, the outer and inner circumferences of the shell may be substantially circular, i.e. the shell is a true annulus or ring. However, annuloid structures which in radial section are elliptical, polygonal or any other closed hollow shape with a central core are also within the scope of the present invention.
The shape of the core itself may be of any convenient kind, for example generally cylindrical. Although the core itself will usually be substantially hollow, in some embodiments it may be advantageous to locate some of the ancilliary equipment of the wave collector inside the core. Moreover, in many embodiments, the core will be open to the external environment at both ends thereof. However, it is also within the scope of the invention for the hollow core to be substantially closed at one or both ends, provided that means are provided to enable water and/or air to enter and exit the core substantially freely.
It is especially preferred for stability reasons and for optimal wave tuning that the diameter of the annuloid shell is not substantially less than its height.
Overall, the annuloid configuration provides good stability whilst the collector is being towed in the water and when it is anchored in place for operation. At the same time, it provides an advantageous arrangement for the containment and ducting of the air which takes up the kinetic energy of the waves. The structure is also particularly cost-effective in terms of raw material and labour costs incurred during construction.
In axial cross section, the annuloid collector may also have any convenient shape, for example circular.
However, it is preferred that the collector shou
REFERENCES:
patent: 2190003 (1940-02-01), van Hulsk
patent: 2919552 (1960-01-01), Hayward
patent: 4221538 (1980-09-01), Wells
patent: 4383413 (1983-05-01), Wells
patent: 4719754 (1988-01-01), Nishikawa
patent: 5005357 (1991-04-01), Fox
Cuneo Christopher
Stephan Steven L.
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