海洋エネルギーの多目的利用について
―対馬海域の場合―

抄録

The present paper describes the multi-purpose utilization of ocean thermal energy offshore of Tsushima Island.
The practical application of ocean thermal energy conversion (OTEC) and desalination plants is expected due to shartages of electric power, drinking water, new industry and development of fisheries resources on Tsushima Island. We conducted oceanographic observations in the area northwest of Tsushima Island in August, October and November 2005; July, August, October and November 2006; August, September, October and November 2007, and November 2008 to obtain physical and chemical data (water temperature, salinity, dissolved oxygen, nutrients and velocity of currents) and topographic data, which is necessary for designing an Integrated Hybrid OTEC System (I-H OTEC system).
A conventional design for the I-H OTEC system is being conducted with these data.
In this paper, numerical results are reported for a 1,000kW I-H OTEC system with plate-type heat exchangers and ammonia as a working fluid and described for effect of the variation in salinity of sea water for an I-H OTEC system.
The objective function obtained is 9.87m²/kW when the warm sea water inlet temperate is 28.7°C and cold sea water inlet temperate is 4.1°C.
The ratio of objective function γ′_min to γ_min (35‰) is 0.97 when γ′_min is valve in the case of 30‰ salinity of surface sea water and 35‰ salinity of deep sea water and γ_min is the valve in the case of 35‰ salinity of surface and deep sea water.
The ratio of objective function γ′_min to γ_mi (35‰) becomes smaller when the salinity of surface sea water is higher than the salinity of deep sea water.