Supercritical CO2 Brayton cycle: A state-of-the-art review

Abstract Against the backdrop of energy conservation and emission reduction, the development of power generation technology has always been focusing on higher efficiency with lower cost, where using renewable energy source or waste heat is one of the solutions. The supercritical CO2 Brayton cycle (SCBC) not only predicts remarkable advantages of high efficiency and compact equipment sizes in the moderate temperature range (450–750 °C), but also provides the disadvantages of material problem due to high temperature and pressure. The SCBC can be applied to solar energy, nuclear power, high-temperature fuel cells and waste heat sources. This paper makes a description of the SCBC as well as the properties of its working fluids supercritical CO2. In addition, the paper also summarizes different structural forms of SCBC, applications of SCBC to different heat sources, thermodynamics of SCBC, multi-objective optimization of thermodynamics and economics of SCBC, complete test equipment of SCBC, and main components design of SCBC. Future researches should focus on raising the efficiency of turbomachinery, designing compact heat exchangers, building up large-scale experimental facility, optimizing configurations of SCBC, and improving control strategies, etc. In short, SCBC is promising, but it still requires more researches on commercialization.