Muroran Institute of Technology

Hideo Kondo

Kenji Yano

Tomiji Watabe

Seiichi Asano

Matao Takagi

Kyokai Okuda

Yasuhiko Dote

Toshihiko Matsuda

According to the present invention, a simple, strong and economical resonant type apparatus for absorbing wave energy which can generate electric power at high efficiency, yet can withstand extraordinary sea phenomenon such as typhoon with minimum investment and maintainance costs.

Method and apparatus for absorbing wave energy and generating electric

At least one caisson which is part or all of a breakwater forms a water chamber therein whose closure is a pendulum having a natural period in rocking or oscillating the same as a period of stationary wave surges caused in the water chamber by rocking movement of the pendulum owing to wave force impinging against the pendulum. At least one double-acting piston and cylinder assembly is connected to the pendulum, so that when a piston of the assembly is reciprocatively moved by the pendulum, pressure difference between cylinder chambers on both sides of the piston of the assembly controls a change-over valve which in turn controls hydraulic pressure discharged from the cylinder chambers to be supplied to a plurality of hydraulic motors respectively having accumulators of a type wherein accumulated pressure and volume of the hydraulic liquid are proportional to each other, whereby driving a common generator alternately by the hydraulic motors.

Method and apparatus for generating electric power by waves

A wave energy absorber comprising a caisson mountable on the seaside surface of an existing breakwater or coastal embankment, which caisson has a water chamber with an open side and a rear wall facing the open side. The distance from the open side to the rear wall is longer than one quarter of a wavelength L.sub.c in the water chamber so as to generate a standing wave in the water chamber with a node of the standing wave at a distance L.sub.c /4 from the rear wall toward the open side. A wave-power turbine impeller is pivotally supported in the caisson at the node position, the impeller rotating in only one direction, whereby wave energy is absorbed by the impeller for further conversion into electric or thermal energy. The caisson itself can also be utilized as a breakwater or an embankment.

Wave energy absorber mountable on wave-facing structure

A resonant type apparatus for absorbing wave energy arranged at wave-breaking facilities, which comprises, a caisson having a bottom plate, side plates, a backside plate and a top plate at least a part of which is omitted. A water chamber in the caisson has a length in a directional parallel to the side walls which is larger than 1/4 of the wave length Lc of a stationary wave within the water chamber, and a node of the stationary wave in the water chamber is formed at a distance Lc/4 from the backside plate. A pendulum is arranged at the position of the node of the stationary wave for swinging with a natural period Tp which is substantially the same value as the natural period Tw of the stationary wave, whereby the pendulum is swung by the stationary wave to absorb and convert wave energy to useful available energy at high efficiency.

Growing community of inventors

Muroran, Japan

Hideo Kondo