Pressure Pulsation Signal Analysis for Centrifugal Compressor Blade Crack Determination

Abstract EN

Blade is a key piece of component for centrifugal compressor.

But blade crack could usually occur as blade suffers from the effect of centrifugal forces, gas pressure, friction force, and so on.

It could lead to blade failure and centrifugal compressor closing down.

Therefore, it is important for blade crack early warning.

It is difficult to determine blade crack as the information is weak.

In this research, a pressure pulsation (PP) sensor installed in vicinity to the crack area is used to determine blade crack according to blade vibration transfer process analysis.

As it cannot show the blade crack information clearly, signal analysis and empirical mode decomposition (EMD) are investigated for feature extraction and early warning.

Firstly, signal filter is carried on PP signal around blade passing frequency (BPF) based on working process analysis.

Then, envelope analysis is carried on to filter the BPF.

In the end, EMD is carried on to determine the characteristic frequency (CF) for blade crack.

Dynamic strain sensor is installed on the blade to determine the crack CF.

Simulation and experimental investigation are carried on to verify the effectiveness of this method.

The results show that this method can be helpful for blade crack classification for centrifugal compressors.