Method for designing and monitoring service life of steam turbine rotor under action low-cycle and high-cycle fatigue

Abstract

The invention provides a method for designing and monitoring the service life of a steam turbine rotor under the action of low-cycle and high-cycle fatigue. The method comprises the following steps that S1, obtaining operating parameters of a steam turbine, performance parameters of the steam turbine rotor, crack size parameters, a total service life criterion value tau < 0 > and the operating service life tau; s2, in the design stage of the steam turbine, calculating the theoretical total service life tau CLt of a steam turbine rotor under the action of low-cycle fatigue and high-cycle fatigue; when tau CLt is smaller than tau 0, optimizing performance parameters of the steam turbine rotor, and recalculating tau CLt until tau CLt is larger than or equal to tau 0; s3, in the use stage of the steam turbine, calculating the theoretical residual life tau Rf of the steam turbine rotor under the action of low-cycle fatigue and high-cycle fatigue; and when tau Rf is less than (tau 0-tau), optimizing the operating parameters of the steam turbine, and recalculating tau Rf until tau Rf is less than (tau 0- tau). The method can be used for monitoring the total service life of crack initiation and crack propagation of the steam turbine rotor under the action of low-cycle fatigue and high-cycle fatigue in the design stage and the use stage, and safe service of the steam turbine rotor is guaranteed.

Description

technical field [0001] The invention relates to the technical field of steam turbines, in particular to a life design and monitoring method of a steam turbine rotor under low-cycle and high-cycle fatigue. Background technique [0002] In the transient working conditions of steam turbine startup and shutdown, due to the low cycle fatigue effect caused by mechanical load and thermal load, crack initiation and crack growth occur on the outer surface of steam turbine rotor. During the stable operation of the steam turbine under load, due to the high-cycle fatigue effect caused by the gravity load, crack initiation and crack propagation occur on the outer surface of the steam turbine rotor. Therefore, during the operation of the steam turbine, the transient conditions of start-up and load change and the stable operation condition with load appear alternately, and the steam turbine rotor alternately suffers from low-cycle fatigue and high-cycle fatigue damage, and crack initiation...

AI Technical Summary

Problems solved by technology

However, at present, there is no suitable method for the design and monitoring of the total life of crack initiation and cr

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