Axial flow compressor stall surge prediction device based on frequency characteristic change

Abstract

The invention discloses an axial flow compressor stall surge prediction device based on frequency characteristic change. An inlet dynamic pressure / flow sensor is mounted at an inlet casing wall of a compressor, an outlet dynamic pressure / flow sensor is mounted on the periphery of an outlet casing wall of the compressor, the inlet dynamic pressure / flow sensor and the outlet dynamics / flow pressure sensor are correspondingly connected with a signal acquisition card at the same time, the signal acquisition card is connected with a single-chip microcomputer established with a spectrum characteristic database, a noise energy ratio threshold valve is arranged in the spectrum characteristic database, and the single-chip microcomputer is connected with a controller conducting the surge early warning when the radiation noise energy ratio of the outlet end of the compressor reaches a set noise energy ratio threshold valve. By establishing the spectrum characteristic database, the pressure fluctuation frequency change in a working process of detecting and monitoring the compressor in real time, the frequency spectrum characteristics of the inlet air pressure and the outlet air pressure can becompared, the early warning is effectively conducted on the occurring of the surge before the surge occurs, and the reliability is high.

Description

technical field [0001] The invention relates to the technical field of surge prediction, in particular to a stall surge prediction device for an axial flow compressor based on changes in frequency characteristics. Background technique [0002] Before the compressor enters stall and surge, there is a certain premonitory disturbance, but what is this premonition, different scholars have different opinions. For ideal signals, Moore and Greitzer used the compression system stability theory model to predict the stall precursor in 1986, Tryfonidis used the traveling wave energy method, Bright used the correlation integral method, Hoss used the wavelet analysis, Methling used the artificial neural network method and Tahara used the automatic The relevant algorithm analyzes the dynamic pressure signal of the compressor rotor tip, and can detect the early disturbance of the compressor before entering stall and surge. However, these methods cannot reliably predict the effects of nois...

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Problems solved by technology

[0003] Among the existing compressor surge prediction methods, the invention patent "Automatic Detection and Avoidance Device and Method of Turbocharger Surge on Engine" (Patent No.: 200410045240. The speed of the compressor is used to judge whether surge occurs, and this method only judges the surge phenomenon when the surge occurs, and cannot predict the surge phenomenon before the surge occurs; the invention patent of Wang Yinyan and others "sequential pressurization system Surge Prediction Control Device and Control Method” (Patent No.: 201410571424.3) predicts the occurrence of surge through the speed and air flow of the compressor. However, the arrangement of the speed sensor and flow meter requires holes inside the compressor or on the outer wall of the compressor. This will inevitably affect the original flow field state of the compressor, and this type of prediction is mainly for the surge phenomenon of diesel engines

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