At-Sea Experiments of Ocean-Based OTEC Experimental Facility in toyama Bay

Abstract

At-sea tests on an ocean-based mariculture-OTEC pilot plant using deep seawater were carried out from July 8 to September 7, 1989 and from July 10 to August 7, 1990 off Himi in Toyama Bay, the Sea of Japan. 0.3m³/s of deep seawater and 0.6m³/s of surface seawater were intaken and the mixed seawater of them was sprayed on sea surface in order to obtain the basic data on the enhancement of bio-productivity due to nutrient-rich deep seawater for open ocean. At the same time, OTEC(Ocean Thermal Energy Conversion) power generation experiment was carried out by using one tenth of intaken seawater in order to detect the system characteristics in real sea state. In the practical scale the OTEC power output will be used as a self-sustaining for an ocean-based mariculture-OTEC total system.
According to at-sea tests, the basic design data for a self-sustaining mariculture-OTEC system were obtained; the dependency of OTEC power output on temperature variation of both surface and deep seawater was compared with the numerical model developed by ETL. The performance of each major component such as evaporator, and condenser, which was made of aluminum alloy and had the enhanced surface, was measured. The time dependency of biofouling factor was also detected and the cleaning effect was discussed. It was concluded that this system would be a self-sustainig system if all intaken seawater was used in OTEC power system.