超临界二氧化碳干气密封稳态性能研究

Study on Steady⁃State Performance of Supercritical Carbon Dioxide Dry Gas Seal

以超临界二氧化碳(S-CO2)干气密封为研究对象,建立变黏度变密度雷诺方程,通过构建物性数据库的方式对黏度及密度进行处理,并采用有限差分法对控制方程进行求解,得到端面压力分布,并计算开启力、泄漏量、摩擦扭矩和气膜刚度等稳态性能参数。结果表明:随着压力、转速的增大,开启力、泄漏量、摩擦扭矩、气膜刚度等参数均增大;随着槽坝比和槽深的增加,开启力、泄漏量和气膜刚度均增大,摩擦扭矩减小;随着槽数的增加,各稳态性能参数均减小;将槽坝比控制在0.5-1的范围内,有助于提高密封稳定性。

The supercritical carbon dioxide(S-CO2)dry gas seal was taken as the research object,the variable viscosi⁃ty variable density Reynolds equation was established.The viscosity and density were treated by constructing a physical property database.The governing equation was solved by the finite difference method and the pressure distribution and the steady state performance parameters were obtained.The results indicate that with the increase of pressure and speed,the opening force,leakage,friction torque and film stiffness are all increased.With the increase of groove⁃dam ratio and groove depth,the opening force,leakage and film stiffness are increased,the friction torque is decreased.With the increases of groove number,the steady⁃state performance parameters are decreased.It is helpful to improve the sealing stability by con⁃trolling groove⁃dam ratio in the range of 0.5 to 1.