Océan et énergie - Énergie Thermique des Mers
Sommaire IOA News Letters
OCEAN ENGINEER LOOKS AT POTENIAL OF FLXIBLE CWP
To date, majority of the technologies needed for the commercial development of shore-based CC-OTEC plant; such as heat exchangers, turbines, biofouling control, containment structure, warm-water and discharge pipes etc., are adequate and readily available. The only uncertainty seems to be in the arrangement and deployment of larger diameter cold-water pipe (larger than 3 m diameter). With this understanding, Professor N.K. Liang, an ocean engineer at the Taiwan University, recently proposed a "Flexible Cold-Water pipe Design" for OTEC plants. Professor Liang believes that the difficulties associated with the deployment and installation of cold-water pipe are due to the rigidity of the pipe itself. "When we use the single-length-surface-floating method to deploy the cold-water pipe, curvature will occur during sinking; thus, the pipe will may be broken or damaged by the ocean current drag force." Liang explained. For this reason, he believes that the pipe wall should be made of some soft and flexible materials like synthetic resin and fiber composite material. The flexible cold-water pipe Professor Liang proposed is composed of the soft pipe wall, the stiffner ring, the protection wire and buoy. The pipe can be installed by a bottom-pull method to avoid the undesirable influence due to the ocean current occurred near the surface of the water. Professor Liang has con-ducted some preliminary study based on the ocean data collected from east coast of Taiwan to examine the possibility of using such flexible CWP. The results of his study turn out to be quite promising and he is seeking additional support to carry out further investigations. Professor Liang's flexible CWP is illustrated in the following diagrams:
He also explained "Due to the pollution problem in an already overcrowded country, the public in Taiwan is strongly opposed to building any new coal-fired or nuclear power plants. The search for alternative forms of energy,such as tidal, wind, solar. wave current, bio-gas, geothermal, and so forth, turned out to be very unpromising for one reason or another. OTEC has the advantage because it uses no fuel, creates no pollutants,and seems to be the most promising alternative energy resource for Taiwan."
Dr. Su believes that when the sociological problems, geographical conditions, and multi-purpose utilizations,and multi-purpose utilizations are combined with the technology and economy, Taiwan appears to be the best place in the world for building the OTEC power plant.