Shaft straightening method for sleeving steam turbine rotor

Abstract

The invention discloses a shaft straightening method for a sleeving steam turbine rotor. The method comprises the following steps that 1), original bending degree measurement is carried out on a bentrotor; 2), a cold-state force application experiment is carried out on the rotor, and whether the rotor contains temporary unreleased elastic bending components which are generated by a sleeving impeller shaft section or not is judged, if yes, the follow-up steps are carried out; 3), the rotor is subjected to a hot-state pressurization straightening shaft treatment; 4) the temporary unreleased elastic bending components of the sleeving impeller shaft section in the rotor are eliminated; 5) thermal bending degree measurement is carried out on the rotor, when the measurement result meets the requirement of shaft straightening, entering the step 6, and when the measurement result does not meet the requirement of shaft straightening, returning to the step 3; and 6), tempering treatment is carried out on the rotor. According to the shaft straightening method, whether the sleeving impeller shaft section of the rotor generates the temporary unreleased elastic bending components or not can bejudged, and when the judgment result is yes, eliminating treatment is carried out on the temporary unreleased elastic bending components, so that a real and accurate bending degree measurement value can be obtained, and the shaft straightening effect can be improved.

Description

technical field [0001] The invention relates to the technical field of steam turbines, in particular to a direct shaft method for fitting steam turbine rotors. Background technique [0002] A steam turbine is a rotating machine powered by steam and converts the thermal energy of steam into mechanical work. It is the most widely used prime mover in modern thermal power plants. The steam turbine includes a cylinder and a rotor installed in the cylinder. The rotor includes a main shaft, an impeller and a coupling, etc. on the main shaft. The impellers of some rotors are separately processed and shrunk on the main shaft to form a sleeve rotor. [0003] The rotor in the steam turbine may cause permanent bending of the main shaft due to frictional overheating, water invasion and other reasons. It is necessary to carry out straight shafting on site. Specifically, the main shaft is heated on the entire circumference of the largest bending part of the main shaft to 30°C-50°C lower th...

AI Technical Summary

Problems solved by technology

[0004] In the process of fitting the direct shaft of the steam turbine rotor, the applicant discovered for the first time that during the process of adding force to the main shaft, due to the insufficient interference fit between the impeller and the main shaft, relative sliding occurred between the mating surface of the impeller and the main shaft, such as figure 1 As shown, the main shaft produces unreal temporary bending and affects the measurement of the true value of the bending degree in the straight axis process, resulting in poor straight axis effect

[0005] In summary, how to solve the problem of relative sliding between the impeller and the main shaft joint surface in the installed rotor, resulting in delayed release of elastic bending, and affecting the measurement of the bending degree during the straight-axis process is a key problem in the on-site direct-axis process of the installed steam turbine rotor

Images