Multi-rotor joint vibration mode balancing method for single support shafting steam turbine generator unit

Abstract

The invention discloses a multi-motor joint vibration mode balancing method for a single support shafting steam turbine generator unit. At present, during on-site dynamic balancing of a single support shafting supercritical steam turbine generator unit, vibration information of two ends of rotors is not provided and shaft vibrations influence each other by coupling, so that a certain difficulty is brought into the on-site dynamic balancing of a shafting. According to the multi-rotor joint vibration mode balancing method, unbalanced types of the shafting are judged and calculated by calculating vibration vectors and vibration mode harmonic components and combining characteristics of a single supporting shafting structure according to shaft vibration magnitude values and shaft vibration phases of each rotor of the shafting at a critical rotating speed and a working rotating speed, and then a joint vibration mode of multiple rotors is identified; and a weight-increasing scheme of each plane is directly obtained according to a lag angle, mass-basis response coefficients and a first-time weight-increasing interval, and a group of increased weights are added to a related plane once. By the multi-motor joint vibration mode balancing method, the balancing efficiency and the accuracy of the single support shafting rotors are significantly increased.

Description

technical field [0001] The invention relates to the field of fault diagnosis and vibration treatment of an ultra-supercritical turbo-generator set, in particular to a multi-rotor combined vibration-shape balancing method for a single-supported shaft system ultra-supercritical turbo-generator set. Background technique [0002] SAIC-Siemens ultra-supercritical turbogenerator unit is becoming the most competitive coal-fired unit in my country in the early 21st century due to its technical advantages of high efficiency, energy saving and environmental protection. The market application prospect is very good. By the end of 2010, it has More than 30 units of 1000MW and 660MW were put into operation. This type of steam turbine unit adopts a unique single-bearing support structure. The single support reduces three bearings, and the vibration monitoring of the rotor also reduces the measuring point information at three planes correspondingly. Only the vibration information of a single...

AI Technical Summary

Problems solved by technology

This type of steam turbine unit adopts a unique single-bearing support structure. The single support reduces three bearings, and the vibration monitoring of the rotor also reduces the measuring point information at three planes correspondingly. Only the vibration information of a single end of the rotor can be tested. There is no mutual phase relationship, and the first-order and second-order vibration shapes of the rotor cannot be judged from the mutual phase relationship of the rotor

When the vibration failure of the single-supported shafting ultra-supercritical unit occurs, the power frequency vibration is unstable. Regardless of the no-load constant speed or the load process, the power frequency vibration always fluctuates and changes drastically, and there is a strong coupling effect between the shaft vibrations. The on-site dynamic balance processing brings certain difficulties

[0003] For the vibration signal characteristics of a single-supported shafting unit, it is very difficult to deal with the shafting dynamic balance of the unit using two classic dynamic balancing techniques (mode balance method and influence coefficient method).

The vibration information and phase relationship between the two bearings can no longer reflect the mode shape relationship, and the correct vibration mode balance correction quality cannot be given

Simply use the influence coefficient method to balance the flexible rotor of the single-supported shafting ultra-supercritical unit. Due to the mutual coupling of the shaft vibration, the amplitude of the shaft vibration and the pad amplitude fluctuates greatly, making the calculation result sensitive to the measurement error, which may easily lead to a large balance error. The range of aggravation given is so large that it cannot be implemented on site

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