A Seismic Analysis on Steam Turbine Considering Turbine and Foundation Interaction

This paper presents a seismic analysis on steam turbine within a Nuclear Power Plant. Firstly, considering that steam turbine is a kind of large equipment with complex structure, high precision and tightly connected with other equipments and structure, this paper coupled together the steam turbine, condenser and its spring foundation as a whole structure for analysis, and created detailed finite analysis models for almost each part. Secondly, the detailed model of steam turbine, condenser and spring foundation was analyzed separately to obtain their dynamic properties (inertia, eigenvalues etc.) to verify whether the detailed finite analysis models were correct and proper. Thirdly, with seismic analysis on the whole structure with time-history method, relative displacement time history curves of some places, as well as stress response of LP (low pressure) outer and inner case, was extracted. Finally, the anti-seismic performance of steam turbine, such as rotor gaps using those relative displacement and stress response results, was analyzed and evaluated.