폐쇄형 OTEC 사이클에 관한 연구

초록

In this paper, performance of various working fluids is evaluated for the closed Ocean Thermal Energy Conversion (OTEC) power plant operating on Rankine cycle. The evaporator and condenser are modeled via UA and LMTD method while turbine and pump are modeled by specifying isentropic efficiencies. R22, Propane, Propylene, R134a, R125, R143a, R32, R410A and Ammonia are used as working fluids. Results show that newly developed fluids such as R410A and R32 that do not cause stratoshperic ozone layer peletion perform as well as R22 and ammonia. The superheat at the evaporator exit and subcooling at the condenser exit do not affect the performance of the simple OTEC power cycle. Turbine efficiency and heat exchanger size influence greatly the performance of the Rankine cycle. Fianlly, it was shown that closed OTEC power plants can practically generate electricity when the difference in warm and cold sea water inlet temperature is greater than 20C