Performance analysis of sCO2 tube with high non-uniform heat flux: Thermal-fluid-structural evaluation and optimization

Abstract

A supercritical carbon dioxide (sCO2) tube is an important component in a sCO2 power system for a wide range of heat sources. The sCO2 tubes experience high temperature and pressure with high non-uniform heat flux when fossil fuel and solar energy are used as heat sources. Herein, a novel tube structure is proposed to match the circumferential thermal resistance with the non-uniform heat flux by changing the Eccentricity. A three-dimensional multi-physical coupling model was constructed to compare the proposed structure with a conventional tube. The fluid dynamics, thermal stress, and coupled heat transfer characteristics were analyzed, and the key working parameters were explored. The maximum temperature of the proposed structure was effectively reduced by 13–36 K and the maximum thermal stress was significantly reduced by approximately 25–33% under all the simulated working conditions when the Eccentricity changed from 0 to 0.4. The proposed novel structure will facilitate the safety and conserve tube material, and the results can serve as a reference for the development of sCO2 power systems for industrial applications.