Fault Diagnosis of Screw Pump Based on Correlation and Multi-Order Fitting

摘要

The vibration acceleration of the screw pump at different center frequencies deviates from the normal range, which will cause abnormal vibration of the screw pump. Therefore, the screw pump needs to set different measurement points to detect its vibration acceleration before leaving the factory. For this reason, based on the vibration acceleration of different measurement points of the screw pump under normal operation, this paper applies the Apriori algorithm to obtain the conclusion that there is no significant difference in vibration acceleration between different measurement points of the screw pump and that there is a strong positive correlation. The multi-order fitting method is used to establish the functional relationship between the center frequency and the vibration acceleration of the screw pump. The coefficient vector corresponding to the normal operating parameters is used as a template, and calculate the coefficient distance between the coefficient vector constructed by the operating parameters of the measurement points of the equipment to be diagnosed and the template, then apply statistical methods to design an appropriate threshold to compare with it, and determine the sample to be diagnosed as a fault if and only if the coefficient distance is bigger than the threshold. After practical application, the method in this paper can find the abnormal vibration of the screw pump in time, so as to achieve the purpose of fault diagnosis.