Single-Flow Supercritical CO2 Brayton Cycles: A Performance Comparison of the Different Layouts

Abstract

Supercritical CO2 Brayton cycle (sCO2-BC) has been frequently used in power generation applications in recent years due to its high efficiency, compact size, and low-cost advantages. In this study, performances of different configurations of single-flow sCO2-BCs, such as recuperation, intercooling, reheating, pre-compression, inter-recuperation, and split expansion, are examined. Firstly, thermodynamic analyzes of six different single-flow sCO2-BCs were conducted. Secondly, parametric analyses based on the system performance-influencing parameters, such as turbine input temperature, turbine inlet pressure, and compressor inlet pressure, were carried out. Engineering Equation Solver (EES) computer software was used in the analysis. According to the initially accepted design parameters, the highest energy efficiency was calculated as 39.25 % in the reheating cycle, and the lowest efficiency was found as 29.62 % in the split expansion BC. Moreover, it has been determined that the energy and exergy efficiencies of cycles increase with rising turbine input temperature and turbine input pressure.