1MW 해수온도차발전 시스템의 성능평가 및 개선방안

Abstract

1MW OTEC (Ocean Thermal Energy Conversion) plant was fabricated for the demonstration of practical use of ocean energy, and performance test was carried out in the Southern East Sea. Even though this 1MW class OTEC plant was designed to produce 1 MW power at 24 °C of thermal gradient, it can produce 500 kW power while thermal gradient is decreasing to 20 °C. To verify the performance, this closed cycle OTEC system was consisted by evaporators, a gas-liquid separator, a turbine generator, condensers, a receiver tank, working fluid pumps, pipes and risers, and seawater pumps etc. Fabricated OTEC system was connected with hydrothermal load bank, and operated by power and system control systems. The OTEC barge and risers were installed during relatively calm period between the typhoon Tapa and the typhoon Mitak approach. As a result, it was confirmed that the closed cycle power generation cycle was formed at a temperature difference of 18.4 to 18.9 °C., and the power output was about 326 kW. During the power generation experiment, an external specialized agency boarded to measure turbine speed and generator vibration for safe operation. We consider and analyze the reason why output of generated power could not reach the target value of 500kW such as different thermal gradient, estimated performance of devices. Through the process, it was possible to improve the performance of the OTEC power plant and to arrange directions for system stability.