DETECTING A VALVE SPRING FAILURE OF A PISTON COMPRESSOR WITH THE HELP OF THE VIBRATION MONITORING

Abstract

The article presents problems related to vibration diagnostics in reciprocating compressors. This paper presents the evaluation of several techniques of the digital signal processing, such as the spectrum calculation with the Discrete Fourier Transform (DFT), Continuous Wavelet Transform (CWT), Segmented Analysis for detection the spring failure in reciprocating compressor valve with the help of the vibration monitoring. The experimental investigation to collect the data from the compressor with both the faultless valve and the valve with spring failure was conducted. Three 112DV1 vibration acceleration probes manufactured by TIK were mounted on the cylinder of the compressor. The keyphasor probe was mounted on the compressor’s flywheel. The signal of the vibration acceleration probe mounted on the top of the cylinder was used for the Condition Monitoring and Fault Detection of the valve. The TIK-RVM system of monitoring and data acquisition was used for gathering the signal samples from the probes. The sampling frequency was 30193.5 Hz, signal length was 65535 samples. To imitate the spring fault, the exhaust valve spring was replaced by the shortened one with the same stiffness. As it can be seen from the signal processing results in the article, the techniques used are showing quite different results for the cases of the normal valve spring and the short one. It seems what for this type of the compressor and valve, the valve spring failure can be quite reliably detected with the help of the vibration monitoring. To see if this is a case for other compressor types and other valve types, the additional experiments are needed.