Perspective of S−CO₂ power cycles

In this perspective paper, the research and development of S-CO₂ cycles are analyzed from two aspects: (i) the system design and analysis and (ii) energy transfer/conversion mechanisms and key components development. Based on the analysis, barriers for further promotion of S-CO₂ cycles are summarized, including the lack of system design and analysis methodology, not well understood mechanisms of energy transfer/conversion, and technic barriers such as seal, leakage and roto-dynamics stability of key components. To overcome these issues, perspectives on three aspects are proposed. First, S-CO₂ cycle adapting to the distinct characteristic of a heat source should be optimized to promote the global system efficiency. Second, new theoretical/numerical works are suggested emphasizing the real gas effect of S-CO₂ to improve the accuracy, convergence and stability of numerical simulations, fine experiments should be expanded to verify the correctness of the numerical simulations. Third, the integrated solution strategies for key components such as intermediate heat exchanger, recuperator heat exchanger and turbomachines should be developed and verified in large-scale test loop for reliable and efficient operation. This critical review is hopefully to present readers a clue to promote the development of S-CO₂ cycles driven by nuclear energy, renewable energy and fossil energy.