Exergoeconomic analysis and optimization of a hybrid system based on multi-objective generation system in Iran: a case study

Abstract

The present work aims to study a multi-objective generation system based on renewable solar and wind energy that has been selected according to the climatic conditions of the area under study, i.e. Bandar Abbas, Iran. In general, the system includes six different sections such as solar cycle, single effect absorption chiller, Rankine cycle with ammonia–water fluid, wind turbine, electrolyzer, and multi-stage flushing desalination. First, the system is investigated in terms of thermodynamic and exergy principles. Then, exergoeconomic analysis with specific exergy costing method (SPECO) is carried out based on the concepts of product, fuel, and cost balancing. The sensitivity analysis investigates the effect of decision parameters on energy and exergy efficiencies. Finally, single-objective optimization is analyzed using conjugate method and the multi-objective optimization is analyzed using genetic algorithm. Results show that, based on multi-objective optimization, isentropic efficiency of turbine is 81%, isentropic efficiency of pump is 77%, pressure ratio of Rankine cycle is 40.32, solar cycle mass flow is 0.8 k/s, outlet temperature of boiler is 113.62°C, exergy efficiency is 32.88%, and operating cost rate is 8.45 dollars per hour. Using multi-objective optimization, operating cost rate decreases by 22.6% and exergy efficiency increases by about 5.31%.