静压气体润滑机械密封性能分析

Analysis on the Seal Performance of Aerostatic Gas Lubricating Mechanical Seal

采用解析法分析外加压静压气体润滑机械密封(或称为静压干气密封)的节流孔直径、介质压力、气源压力等对其密封性能的影响。结果表明:节流孔直径、介质压力、气源压力的增加将导致开启力增加;较小的节流孔直径在较小工作气膜厚度下可获得较高气膜刚度;在气源压力恒定的情况下,较大的节流孔直径会导致较大的泄漏率,但随介质压力的增加,气膜刚度及向介质侧的泄漏率都会减小;提高气源压力,气膜刚度增大,在气膜厚度4～6μm之间增幅最为显著且能获得最大刚度;随着气源压力的增大,向端面两侧的泄漏率都有所增大;选用较小节流孔直径、提高气源压力或降低介质压力能保证密封的高刚度,提高其运行稳定性。

：The influences of the orifice diameter, process gas pressure, supplying gas pressure on the seal performances of external pressurized aerostatic gas lubricating mechanical seal（ or called aerostatic dry gas seal） were analyzed by ana- lytical method. The results show that the opening force is increased with the increasing of orifice diameter, process gas pres- sure and supplying gas pressure. Smaller orifice diameter can result in higher gas film stiffness when the work gas film is small;the leakage to the process fluid is increased with the increasing of orifice diameter at the same supplying gas pres- sure. Both the gas film stiffness and the leakage to the process fluid are decreased with the increasing of process gas pres- sure. The gas film stiffness is increased by raising the supplying gas pressure. When the gas film thickness is 4 -6μm, the gas film stiffness increase is large and there is a maximum value. Both the leakages to the process fluid and to the atmos- phere are increased with the increasing of supplying gas pressure. The high stiffness of the seal can be ensured and the op- eration stability can be improved by selecting smaller orifice diameter, decreasing process gas pressure and raising suppl- ying gas pressure.