Accuracy study and stability control of a property-table-based CFD strategy for modeling SCO2 compressors working near the critical point of the fluid. (25th January 2021)

• Record Type: Journal Article
• Authors: Shao, Wenyang; Yang, Jinguang; Wang, Xiaofang; Ma, Ziyue
• Is Part Of: Applied thermal engineering. Volume 183: Part 2(2021)
• Publication Date: 2021-01-25
• Subjects: Supercritical CO2 -- Supercritical fluids CFD -- Thermodynamic property table -- Numerical simulation stability -- SCO2 centrifugal compressor; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2020.116222
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: The effect of property tables on the simulation of a SCO2 compressor is studied. A quasi-symmetric sampling method is proposed to improve the numerical stability. Recommended table resolutions for modeling SCO2 compressors are obtained. The adopted numerical simulation strategy is validated against experimental data. Abstract: Supercritical CO2 (SCO2 ) as a working fluid can significantly reduce the compression work in a Brayton power cycle, especially when inlet conditions of the main compressors are set near the critical point of the CO2 . However, near the critical point, the dramatic variation of the physical properties and the potential phase transformation bring about difficulties in achieving converged and accurate numerical simulations of SCO2 compressors. In this paper, a numerical strategy based on commercial density-based computational fluid dynamics (CFD) solver is adopted to model a SCO2 compressor working near the critical point and is validated against experimental data. The effect of property tables with different functions on the accuracy and stability of the numerical simulation is analyzed and discussed in detail. A new sampling method, named quasi-symmetric sampling, is proposed to improve the numerical stability, and proves to be effective in improving the stability of the numerical simulation with little effect on the numerical result.