T槽干气密封低速运转特性的理论研究

Theoretical Analysis of the Operating Characteristics of T-groove Dry Gas Seal at the Slow Speed Conditions

研究T槽干气密封低速运转特性。考虑滑移流的影响,利用有限差分方法求解修正的雷诺方程,探讨端面气膜压力分布,分析滑移流效应对工作膜厚、端面开启力和泄漏率的影响,以及端面关键几何参数对端面开启力和气体泄漏率的影响规律。结果表明:气膜密封在低速运转时,由于工作膜厚较小,滑移流对密封性能影响较大;T槽的几何参数和操作参数对密封性能有影响,其中几何参数对密封性能均有较大影响。

The operating characteristics of the T-groove dry gas seal at the slow speed conditions were studied. The gas film pressure distribution on the T-groove seal face was explored by solving the modified Reynolds Equation with the consideration of slip flow effects by finite difference method （FDM）. The influence of the slip flow effects on the operating film thickness, the opening force and the corresponding leakage rate, and the influence of key geometric parameters on the opening force and the gas leakage rate of the T-groove gas seal were analyzed. The results show that the effects of the slip flow on the seal performances turn out to be significant at the slow speed conditions due to its thinner operating film thickness. Both the geometric parameters and the operational parameters have certain effects on the seal performances, moreover, the geometric parameters exert greater effects on the seal performances.