Abstract: Taking dynamic characteristics of alarge system “impeller rotor-bearing-dry gas seal” system as a research object, a finite element model has been established by adopting ANSYS software. The model is used to analyze the gas sealing system under full load condition, and natural frequencies and vibration modes in various stages are obtained. The modal analysis of the system under non-loading condition is then carried out, and the natural frequencies under above two conditions are compared and analyzed with each other. Compared with the above two natural frequencies, it is found that the force acting on the dry gas sealing system and the impeller rotor reduces natural frequency of the system. Finally, taking the unbalance of the system as body load, the steady-state unbalanced response curve of the system can be obtained by a harmonic response analysis method.

Key words: dry gas seal, modal analysis, harmonic response analysis