The Analysis of the Bending at HP-IP Rotor of a 660MW Supercritical Steam Turbine Generator Unit

摘要

With power of the steam turbine generator unit arising, the temperature and pressure of inlet steam is getting higher, which makes the steam turbine rotor under a complex heat and force environment. In some area of the shaft, the temperature and stress is in a relative high level which satisfies the condition of creep. When the shaft is under this condition, it will gradually bend with an initial bending. Shaft bending is a serious accident for steam turbine. If not handled properly, it will result in serious consequences. In recent years, the gradually bending phenomenon has occurred in several 600MW or 660MW steam turbines. Taking a 660MW HP-IP turbine shaft bending accident as an instance, the paper analyzes the temperature and stress of the shaft, and simulates the bending process under creep mechanism. Furthermore, the paper establishes the rotor dynamics model to analyze the dynamic response of the rotor bending, and construct the relationship between vibration amplitude and bending amount, which will provide a basis for decision of condition-based maintenance.