Compressor Valve Disc Fault Analysis And Diagnosis

In recent years machinery fault diagnosis technology has been greatly developed all over the world and the technology is very important in national production. It is rather difficult to monitor the state of reciprocating compressor owing to its complex construction and so many stimulation sources. Although the researches have been made and some achievements have been gained, the total diagnosis level isn't very high and does not match with practical application. The research on reciprocating compressor fault diagnosis is of great significance owing to the particularity of its application. The research work which is combined with practice in this thesis is based on predecessors' achievements, intelligent diagnosis methods are adopted and fault diagnosis is effectively solved for reciprocating compressor valves.In this thesis the denoising method and the feature extraction method are researched according to valves signals characteristic that periodic signals, impact signals and random signals etc are intermixed, signals feature is difficultly extracted and so on. The rule of choosing wavelet basis function and wavelet denosing soft-thresholding valve is proposed after making further research on wavelet transform technique using for signals disposing of valve's disc. Denoising disposing and feature extraction of signals are carried on through using wavelet transform technique. Feature vectors of signals are constructed by way of "energy" element. Directly gained information is very finite from original data of vibration signals. Therefore, the feature extraction method of information fusion is proposed. Wavelet packet is used to extract "energy" feature of vibration signals in the method. Information fusion is carried out to extract valve disc's feature. Feature vectors of fusion are used for fault diagnosis. Its feasibility and validity are verified by the diagnosis result on vibration signals of valve disc's signals.This article takes a compressor experiment as example, measuring the compressor valve disc's vibration signal on normal and fault condition. The author not only analyses the fault of different degree on compressor valve's disc by the Wavelet Packet Theory, but also searcher the way to pre-judge the fault by the vibration signal of the compressor valve's disc. This article provides a kind of new method for diagnose the miniature compressor valve's fault.