Dynamic Behaviors Analysis Of Dynamic-Hydrostatic Hybrid Lubrication Gas Face Seal

Based on the principle of dynamic gas face seal (DGFS) and hydrostatic gas face seal (HGFS), a new kind of gas face seal, namely dynamic-hydrostatic hybrid gas face seal (DHHGFS), is proposed. DHHGFS has both the hydrodynamic pressure groove of DGFS and external quench gas of HGFS simultaneously. However, at present, the research on the DHHGFS is very weak at home and abroad, especially on the dynamic characteristics of DHHGFS. So in this paper, the dynamic characteristics of DHHGFS are researched in order to guide its project design and operation.The gas film dynamic performance parameters of DHHGFS are obtained from the unsteady nonlinear Reynolds equation using the perturbation method, and the finite element method is presented. The influences of the perturbation frequency of compensation ring, structural parameter and operation parameter on dynamic performance parameters of DHHGFS are analyzed.The kinetic model for perturbation motion of compensation ring is built, the perturbation motion equation of compensation ring is solved using the Laplace transform. The dynamic tracking of compensation ring is analyzed under the simple harmonic excitation of three directions. The influences of operation parameter, spring stiffness, O-ring damping on the dynamic tracking of compensation ring are analyzed.The differential equation of free vibration of compensation ring is solved, and the critical instability criterion of free vibration is obtained. The influence of quench gas pressure on the stability of free vibration is researched, and the change rules of gas film thickness for active regulation is analyzed. The DHHGFS anti-jamming scheme is proposed based on the membrane restrictor.The hydrostatic lubrication lead to DHHGFS face opening is researched based on the critical opening quench gas pressure, and the change rules of gas film thickness for face opening is obtained. The seal characteristics of DHHGFS is analyzed when the quench gas is cut off.In order to research the free vibration stability of active regulation and the vibration performance of compensation ring when the seal is running, the DHHGFS is designed and manufactured. The experimental research results and theoretical research results are compared, which verify the theoretical research is correct.In a word, the research on the dynamic characteristics of DHHGFS can provide the theory basis for its project design and operation, and also promote its industrial application.