超临界二氧化碳闭式布莱顿循环系统研究进展

The supercritical carbon dioxide (SCO₂) closed Brayton cycle has received considerable attention in the field of energy and power due to its advantages of high thermal efficiency and compactness, economy, and environment friendliness. This study reviews research on the SCO₂ closed Brayton cycle in terms of its operating principle, advantages, and domestic and overseas research progress. Key techniques such as cycle thermodynamics, turbomachinery working with supercritical medium, high-efficiency compact heat exchangers, control strategies, and thermal storage are analyzed. Moreover, difficulties in and challenges of engineering applications are discussed, and future development directions are presented. It is indicated that the low-dimensional performance analysis of components should be involved in the conceptual design of cycle thermodynamics to estimate the attainable performance of components, considering the lifecycle performance, compactness, and economy of the cycle. The dramatic variations of working medium properties would lead to special flow and heat transfer mechanisms in turbomachinery and heat exchanger, respectively, motivating the design methodologies for turbomachinery and compact heat exchanger that fully consider the effect of special properties of working medium. The similarity method constructed by theoretical analysis and deep machine learning could provide theoretical foundations for experimental validation of the aerodynamic performance of SCO₂ turbomachinery. Furthermore, robust and efficient control strategies could control the cycle effectively, and SCO₂ closed Brayton cycles integrated with thermal storage techniques adopting novel thermal medium would provide key technical supports for concentrating solar power at high operation temperature.