A Bending Detection Method of Steam Turbine Major Shaft

Abstract

The invention provides a detection method of bending of a rotor of a steam turbine. The method includes following steps: S10, monitoring the steam turbine, and obtaining monitoring data in processes of starting and shutdown of a set; S20, generating a Bode plot of shafting vibration with the change of the rotating speed in the processes of starting and shutdown of the set according to the monitoring data; S30, determining the rotor is bent if a second detection threshold is exceeded, and moving to step S40 if not, wherein the preset second detection threshold is used for comparing vibration values changed with the rotating speed in the shafting starting process; and S40, determining the rotor is bent if a third detection threshold is exceeded, wherein the preset third detection threshold is used for comparing the Bode plot changed with the rotating speed at this shafting start and shutdown. According to the method, an online vibration monitoring and analysis system of the steam turbine is applied, vibration spectrum analysis, a set vibration pass value, a turning current, and the rotor shaking degree are combined, and the function of accurate determination of the bending of the rotor can be realized.

Description

technical field [0001] The invention relates to the technical field of real-time state detection of a steam turbine, in particular to a method for detecting the bending of a large shaft of a steam turbine. Background technique [0002] Steam turbine is one of the main equipment of thermal power plant, its importance is self-evident. The bending accident of the large shaft of the steam turbine has always been the most prominent one among the vicious accidents of the steam turbine generator set. Once a large shaft bending accident occurs, the vibration of the steam turbine will increase, friction will occur in the dynamic and static parts, and the shaft system will break and the bearing bush will burn out. Equipment Security. There have been many major axis bending accidents at home and abroad, such as the major axis bending accident of No. 1 unit of Chaoyang Power Plant in 1998, and the bending accident of high-pressure rotor of No. 2 steam turbine of Huaneng Shantou Power ...

AI Technical Summary

Problems solved by technology

Although this conventional method of judging the bending of the major axis is relatively accurate, it also has some disadvantages.

If the vibration value does not exceed the limit when the unit is running, the idling time is not significantly shortened, and the cranking can be put into operation smoothly, it is easy for the operating personnel to relax their vigilance and ignore the judgment of the bending degree of the large shaft

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