A real gas-based throughflow method for the analysis of SCO2 centrifugal compressors

Abstract

The supercritical carbon dioxide Brayton cycle is recognized as a promising candidate for the next generation of nuclear power and energy system. Among all the components in the cycle, the centrifugal compressor is one of the most important ones. This paper presents a streamline curvature throughflow method based on real gas properties and capable of dealing with condensation flows in the supercritical carbon dioxide compressors. A fluid thermodynamic property calculation method based on look-up tables is adopted to account for the real gas effects and fluid condensation and to reduce the computational time. For extending the simulation capability to the region below the saturation curve to assess the condensation possibility, the homogeneous equilibrium model is adopted. Finally, the real gas-based streamline curvature method is applied in the analysis of a supercritical carbon dioxide centrifugal compressor working near the critical point. Then, computational fluid dynamics calculations are performed to validate the method in detail. The results of the computational validation indicate that the real gas-based streamline curvature method presented in the paper can obtain an accurate enough flow field as that obtained by three-dimensional computational fluid dynamics simulations considering the coarse grid and the much less calculation time.