New procedure for an optimal design of an integrated solar tower power plant with supercritical carbon dioxide and organic Rankine cycle and MED-RO desalination based on 6E analysis

Abstract

In this paper, an innovative structure for the production of electricity and freshwater in Kangan Port, located in southern Iran and close to the Persian Gulf, is developed and analyzed. Heliostat collectors are employed in this process to provide the necessary thermal energy in the supercritical carbon dioxide (S-CO2) cycle, the organic Rankine cycle (ORC) and desalination unit. Additionally, implementing the current multi-effect desalination (MED) processes unit with the reverse osmosis (RO) system as well as employing the sun's thermal collector field to enhance the system's achievement and propose the best plan for the unit that operates has been looked into. ASPEN HYSYS software, Meteonorm package, and MATLAB programming are used to simulate the proposed system. Concurrently, this integrated power plant exhibits the capacity to simultaneously generate 117 kg/s of freshwater and yield 25.14 MW of power. The integrated structure has a thermal efficiency of 36% and a overall exergy efficiency of 31.99. Exergy study reveals that heat exchanger 8 and turbine 3 experience the most exergy destruction. To recover lost heat and produce additional electricity, organic Rankine cycle are used. Investigations are done on seven organic fluids in the ORC unit. The system is better understood from several views with the assistance of energy, exergy, exergoeconomic, exergoenvironmental, emergoeconomic, and emergoenvironmental (6E) analyses. In this regard, m-file codes in MATLAB programming for 6E analyses are developed. The generated code's thermodynamic simulation is accurately compared to ASPEN HYSYS software. Additionally, sensitivity analysis depending on the primary parameters is carried out. For a thorough study of each component, advanced exergy-based analysis linked to avoidable/endogenous and unavoidable/exogenous segments is carried out. The objective functions and chosen variables are optimized using a genetic algorithm. The best organic fluid in terms of thermodynamics is n-hexane and the ideal organic fluid from an economic and environmental standpoint stands R-113. The overall system's cost rate and environmental impact are obtained at 0.1679 $/s and 0.000545 pts/s, respectively.