The Influence Analysis of Centrifugal Inertia Force Effect on the Flow Field and Sealing Characteristics of Supercritical Carbon Dioxide Dry Gas Seal

In order to reveal the influence law of centrifugal inertia force effect on the flow field and sealing characteristics of supercritical carbon dioxide dry gas seal, by using the spiral groove dry gas seal as the research object, the Reynolds equation considering centrifugal inertia force effect was cited. Considering the effect of real gas effect and viscosity of gas film with pressure and temperature changes, based on the Navier-Stokes equation and the law of conservation of energy, the energy governing equation considering the effect of centrifugal inertia force in adiabatic state was established. Then, the finite difference method was used to solve the pressure control equation and the energy control equation, and the pressure distribution, temperature distribution and sealing characteristics with and without centrifugal inertia force effect were analyzed and discussed. The research showed that the pressure and temperature in the flow field was weakened by the centrifugal inertia force effect. From the view point of avoiding condensation flow, the temperature drop caused by centrifugal inertia force effect was not conducive to S-CO₂ dry gas sealing. When the centrifugal inertia force effect was considered, the opening force of the gas film had the best working point at different depth and speed, the leakage rate decreased significantly with the increase of rotational speed, but there was no strong interaction between the centrifugal inertia force effect and the film thickness. Taking into account the action of centrifugal inertia force effect, the opening force, leakage rate, and outlet temperature of gas film were smaller than that without considering centrifugal inertia force effect, and the difference increased with the increase of rotating speed, but didn't change with the variation of film thickness. These results provided a certain theoretical foundation for further research on supercritical carbon dioxide dry gas seal.