A study of response characteristics of a steam turbine governing system in the presence of friction and clearance

Due to component wear, working oil-related pollution and ingress of foreign matter there may emerge cases of friction and an enlarged clearance in the governing system of a steam turbine. The foregoing can lead to a system limit-ring oscillation. When the friction resistance increased to a certain degree, seizure of moving parts may take place, posing a serious threat to the safety of the turbine unit. From the perspective of time-domain response and the analysis of frequency spectrum the authors have studied the response characteristics of the steam turbine governing system in the presence of friction and clearance. With the response characteristics of the friction and clearance being identified the present paper can serve some useful purpose for system status monitoring and failure diagnosis.