抄録
The steam-flow-excited vibration and bearing oil whirl are two main faults affecting the safe operation of large steam turbines. According to the non-linear vibration theory and fluid dynamics, the model of steam exciting force in the condition of partial steam admission in governing stage, as well as the steam turbine nonlinear dynamic model with the steam exciting force and the bearing oil-film force, are deduced in this paper. The numerical calculation method is employed to analyze the vibration response of nonlinear rotor system. The bifurcation diagrams of rotor system are obtained under the action of the steam exciting force and the oil-film force separately, as well as in coupling condition. The coupling performance between the steam exciting force and the oil-film force are discussed, and the coupling influence of the steam exciting force and the oil-film force upon the stability of rotor system are analyzed. The results can provide theoretical basis for the performance study of steam-flow-excited in large steam turbine.
