Multi-Objective Optimization of Thermo-Ecological Criteria-Based Performance Parameters of Reheat and Regenerative Braysson Cycle

Abstract

Abstract The reheat and regenerative Braysson cycle being an alternative for combined cycle power plants needs to be optimized for its efficient utilization of energy resources. Therefore, to obtain the best possible overall pressure ratio, regenerator effectiveness, and pressure ratio across multistage compression in order to simultaneously maximize exergy efficiency, nondimensional power density (NDPD), and ecological coefficient of performance (ECOP) for three different maximum temperature situations, multi-objective optimization of the above cycle is carried out using nondominated sorting genetic algorithm-II (NSGA-II). The optimal solutions given by the Pareto frontier are further assessed through widely used decision makers namely LINMAP, TOPSIS, and Bellman–Zadeh techniques. The optimal solutions attained by the decision-making process are further evaluated for their deviation from the nonideal and ideal solutions. The optimal solution obtained through TOPSIS possesses the minimum deviation index. Finally, the results are authenticated by performing an error analysis. Such optimal scenarios achieved for the three maximum temperatures are further analysed to achieve the final objective of the most optimal solution which happens to be at 1200 K. The simultaneous optimization of performance parameters which reflect the thermo-ecological criteria to be satisfied by a power plant has resulted in values of 0.479, 0.327, and 0.922 for exergy efficiency, nondimensional power density, and ecological coefficient of performance, respectively. These optimized performance parameters are obtained for an overall pressure ratio of 7.5, regenerator effectiveness of 0.947, and pressure ratio across multistage compression of 1.311.