Numerical study on sealing performance of supercritical carbon dioxide compressor dry gas seal

Abstract

Aiming at the serious problem of gap leakage between the stator and rotor of the supercritical carbon dioxide compressor, the dry gas seal scheme for centrifugal compressor of small S-CO2 power system is designed in this paper. The sealing characteristics of the single-stage spiral groove dry gas seal in the S-CO2 operating environment are studied by the large-scale commercial CFD numerical analysis software ANSYS CFX. The leakage characteristics of the S-CO2 dry gas seal at different film thicknesses are obtained. The results show that the S-CO2 dry gas seal leakage flow rate increases linearly with the increase of the film thickness. The dry gas seal leakage flow rate under different film thickness is 0.04%∼0.45% of the S-CO2 compressor flow rate, which can meet the leakage requirements of the centrifugal compressor shaft end seal in the small S-CO2 power system.