Work

Investigation of the heat transfer of supercritical carbon dioxide in a vertical tube under high-temperature and high-pressure conditions

Year: 2026

Type: article

Abstract: The design and refinement of the supercritical carbon dioxide (S-CO 2 ) direct cycle nuclear energy system are crucial for advancing the application of green energy and mitigating the energy crisis. The key to this lies in the research on the heat transfer characteristics of S-CO 2 fluid. Previous studies primarily focus on the heat transfer behavior of S-CO 2 near the critical point, leaving a significant gap in understanding its characteristics under high-temperature and high-pressure conditions. To address this gap, this paper investigates the heat transfer characteristics of S-CO 2 fluid in a vertical tube at pressure and fluid temperature up to 14 MPa and 451℃, respectively. By evaluating the classical heat transfer correlations, it was found that the Krasnoshchekov et al. (1964) correlation provides the most accurate predictions, while the Chen and Fang (2014) correlation is the most stable. The study found that the corrections of Gr number, density, and viscosity have a significant impact on the prediction results. The magnitude of these correction effects is influenced by heat flux. Based on these findings, a new heat transfer correlation was proposed, which demonstrates excellent accuracy and generalization capability for both the experimental data in this study and external data, providing a reliable tool for heat transfer prediction under high-temperature and high-pressure conditions. This paper can serve as a reference and provide data support for the design of S-CO 2 reactor fuel assembly.

Source: Annals of Nuclear Energy

DOI: 10.1016/j.anucene.2026.112894