OTEC performance evaluation using different working fluids and variations in operating ORC conditions

Abstract

Ocean Thermal Energy Conversion (OTEC) is a system that produce energy of electricity by exploiting the temperature difference between surface part of seawater and deep region of seawater. The thermal energy at the surface seawater is used to convert working fluid into vapor which expands in the turbine to generate electricity and revert into liquid state by rejecting heat to cold seawater pumped from deep region of seawater. Basically, there are various types of working fluids that can be applied in an OTEC system depending on its contribution towards the performance of the system. In this study, the thermodynamics efficiency and net power output of basic OTEC system will be evaluated by varying three parameters which are the turbine inlet temperature, turbine inlet pressure and condenser outlet temperature using various working fluids through simulation using MATLAB. Simulation results indicate that R717 excels in producing the highest net power output but R600a has the best average value in thermodynamic efficiency. The findings of this work can contribute in giving an insight on which working fluid has the optimal characteristics in obtaining the best performance of the OTEC system.