Optimization of organic Rankine cycle using ocean thermal energy based on NSGA-II

Abstract

The organic Rankine cycle is one of the key methods to utilize ocean thermal energy, which is abundant and continuous renewable energy. In this paper, a non-dominated sorting genetic algorithm-II (NSGAII) based approach is utilized to optimize an organic Rankine cycle-based ocean thermal energy conversion system. The objective is to maximize the degree of thermal energy utilization and the maximum system power output in. The decision variables considered for optimization include evaporation temperature, condensation temperature, degree of superheating, and working fluid mass flow. The objective functions are defined as thermal efficiency and net power output. The optimization process for the ocean thermal energy conversion Rankine cycle is performed using NSGA-II. The results indicate an inverse relationship between thermal efficiency and power output, meaning that achieving the highest thermal efficiency does not necessarily result in the highest net power output. The utilization of NSGA-II enables the identification of multiple optimal solutions that lie on the Pareto front, representing the best trade-off between thermal efficiency and power output. By considering the investment cost constraint, the most suitable solution for achieving the maximum net power output can be determined.