Performance comparison of Ocean Thermal Energy Conversion(OTEC) plant performance for equatorial applications.

Abstract

This study analyzes the performance of a 50 kW Ocean Thermal Energy Conversion(OTEC) cycle for equatorial island countries. To compare the net power output, the diameter and length of the surface water and deep water pipes and their losses were obtained, and the height from the pump pit to the shore was reflected in the power requirement calculation. The performance of the cycle was compared for a total of five types of working fluids, including natural, HFC, and HFO. Among them, one working fluid was selected in consideration of environmental impact, cycle performance, and core component compatibility, and cycle optimization was performed for the selected operating fluid. The working fluids used for the comparison were ammonia, R32, R1234yf, , R1233zd(E), R1234ze(E), and R1234ze(Z), of which R1234ze(Z) was selected as the optimal operating fluid and cycle optimization was performed for it. For performance comparison, the gross power of the turbine, surface water, deep water flow rate, and seawater pumping power were obtained, and the net power output for each working fluid was derived and compared. For the analysis, the turbine inlet temperature fixed at 24℃ and the working fluid flow rate for 50kW power generation were assumed, and the 50kW output of the cycle for each working fluid was derived through the turbine inlet pressure and outlet pressure in the operable range based on the working fluid temperature of 24℃. After the performance comparison, optimization was conducted to reduce the parasitic load for the selected working fluid.