개방순환식 해수온도차발전 성능개선 방안

Abstract

Open cycle (OC) ocean thermal energy conversion (OTEC) utilizes the temperature difference between warm surface seawater and cold deep seawater. A flash evaporator maintains low vacuum (i.e., about 1-3% of atmospheric pressure), which is lower than the water vapor pressure at the warm temperature. As the warm seawater is transformed to its vapor phase, gas flow is generated and used to rotate a turbine for electricity generation. This evaporated water is then condensed as pure water using cold deep seawater. In steady state, the rate of evaporation is equal to that of condensation. OC OTEC generates electric energy as well as desalinated water. During this series of physical processes, a key operation is the effective evaporation of warm surface seawater using the temperature difference. Conventional distillation includes multi-effect distillation, multi-stage flash, and vapor compression evaporation. In recent desalination technology, membrane distillation (MD) is paid close attention due to its capability of high salt rejection (as much as reverse osmosis), feasible installation, and easy operation. On the other hand, osmosis-driven membrane filtration is popular in environmental and chemical engineering applications, including forward osmosis and pressure-retarded osmosis (PRO).wer than the water vapor pressure at the warm temperature. As the warm seawater is transformed to its vapor phase, gas flow is generated and used to rotate a turbine for electricity generation. This evaporated water is then condensed as pure water using cold deep seawater. In steady state, the rate of evaporation is equal to that of condensation. OC OTEC generates electric energy as well as desalinated water. During this series of physical processes, a key operation is the effective evaporation of warm surface seawater using the temperature difference. Conventional distillation includes multi-effect distillation, multi-stage flash, and vapor compression evaporation. In recent desalination technology, membrane distillation (MD) is paid close attention due to its capability of high salt rejection (as much as reverse osmosis), feasible installation, and easy operation. On the other hand, osmosis-driven membrane filtration is popular in environmental and chemical engineering applications, including forward osmosis and pressure-retarded osmosis (PRO).