Blade torsional vibration displacement measurement method based on blade tip timing principle

Abstract

The invention relates to a blade torsional vibration displacement measurement method based on a blade tip timing principle. At the same circumferential position on a case of a rotary machine, two blade tip timing sensors in one group are arranged along the axial direction of a rotor, respectively called as an air inlet side blade tip timing sensor and an air outlet side blade tip timing sensor andused for measuring time of arriving at the blade tip timing sensors by an air inlet side and an air outlet side at the blade tip of the same blade in the same circle; the two blade tip timing sensorsare arranged at a projection point of a maximum displacement position of a torsional resonance blade tip on a blade tip rest position horizontal line, which is called as a torsional resonance projection process, and by combining torsional resonance parameters of the blade, optimal location of the blade tip timing sensors is realized by utilizing the torsional resonance projection process, so as to guarantee that the two blade tip timing sensors can sample a blade tip arrival time signal respectively and accurately under the condition that torsional resonance and torsional non-resonance of theblade occur; and blade torsional vibration displacement measurement is realized.

Description

technical field [0001] The invention belongs to the field of state monitoring of rotating machinery, in particular to a blade torsional vibration displacement measurement method based on the blade tip timing principle. [0002] technical background [0003] Important rotating machinery such as aero engines and steam turbines are the core components of key equipment such as military aircraft, commercial aircraft, generator sets and steam units in the aerospace and industrial fields. In particular, as the core component of rotating machinery, the working state of the moving blade directly affects the working efficiency, safety, stability, and long-term operation of these major key equipment. At present, the vibration measurement technology of rotating blades based on the principle of blade tip timing is a typical non-contact measurement method. The identification algorithm realizes the measurement of blade vibration parameters such as vibration amplitude, vibration frequency a...

AI Technical Summary

Problems solved by technology

Existing tip timing measurement methods, including speed vector end trace method [1] , two-parameter method [2] , autoregressive method [3] and sensor-based arbitrary angular distribution method [4] etc., only one blade tip timing sensor is installed at the same circumferential position of the rotary machine case, so it can only measure the bending vibration displacement of the blade, but cannot realize the measurement of the torsional vibration displacement of the blade

[0006] On the other hand, the mode shapes of the high-order vibration of the blade include bending vibration, torsional vibration, and combined bending-torsion vibration. The blade cracks or corner failures caused by torsional vibration often occur, but because the high-order vibration of the blade has an amplitude Due to measurement problems such as small size, complex mode shape, and difficult sensor layout, there are few researches on the measurement methods of blade high-order vibration parameters at home and abroad, especially for the measurement methods of blade torsional vibration displacement and other parameters.

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