节流孔特性对静压干气密封性能的影响

Influence of Orifice Characteristics on Static Pressure Dry Gas Seal Performance

为提高静压干气密封性能，将节流孔流量项引入到气膜润滑方程，建立改进的N—S方程。利用泛函求极值算法和有限元法，用MATLAB编制相应的计算程序，在节流孔直径和端面间隙变化的条件下进行数值计算，分析气膜厚度、气源压力、节流孔个数和直径对端面开启力和气膜刚度的影响，以及端面压力分布情况。计算结果表明：密封气在流经节流孔后形成显著的压力降，气膜刚度随节流孔径增大而减小，随气源压力增大而增大；端面压力在节流孔处最高，向四周逐渐下降；开启力总体随端面间隙增大而减小，随气源压力增大而增大，端面间隙在2．6—10μm时，开启力随间隙增大而迅速减小，端面气膜具有较大的刚度。

In order to improve the performance of static pressure dry gas seal, the orifice flow factor was introduced into gas film lubrication equation and the improved N-S equation was established. Utilizing functional extremum algorithms and finite element method and using MATLAB to compile the corresponding computer program, numerical calculation was car- ried out under changes of throttle diameter and face clearance. The opening force and gas film stiffness diversifications and increase of orifice diameter and increases with the increase of supply gas pressure. The highest pressure zone appears at the orifice, gradually declining to around. The opening force decreases as face clearance increases and increases with the increase of supply gas pressure, when the face clearance in the range 2. 6 - 10 μm, the opening force decreases rapidly with increasing clearance and with a larger gas film stiffness on the end.