Second-Law Analysis and Exergoeconomics Optimization of a Solar Tower-Driven Combined-Cycle Power Plant Using Supercritical CO2

This paper presents a framework for the first and second law analysis and an exergoeconomic optimization of a solar tower power plant using supercritical CO2, integrated with a combined cycle for electricity production. The system's energy and exergy losses are analyzed to ascertain possible thermodynamic improvement locations. The various design parameters along with direct normal irradiance (DNI) and concentration ratio are considered. Each component of the combined cycle is evaluated to test their energy and exergy performances. The receiver system recorded the highest exergy loss compared with the rest of the system. The levelized energy cost of $0.31/kWh and payback of 10 years proves the economic viability of the design. The optimal design parameters for minimum cost are obtained using the thermoeconomic method. The objective function representing the total cost of the power plant ($/h) is defined as the sum of the operating cost, investment cost of purchased equipment, and maintenance costs. Subsequently, various parts of the objective function are expressed as decision variables and the optimum values of these variables are obtained by minimizing the investment cost and the cost associated with exergy destruction using the genetic algorithm. (C) 2018 American Society of Civil Engineers.