ASSESSING THE INFLUENCE OF THE SCALING FACTOR OF THE BASIC WAVELET TRANSFORM FUNCTION ON THE DEGREE OF MANIFESTATION OF THE MAIN FAULTS OF CENTRIFUGAL PUMPING UNITS IN WAVELET PATTERNS
Authors:   Ufa State Petroleum Technological University, Zakirnichnaya Marina M. , Varlamov Vladimir A. ,   Territorial Compulsory Medical Insurance Fund of the Republic of Bashkortostan, Palladina Yana A. ,   Ufa State Petroleum Technological University
Published: May 2024

Relevance Rotary-type machines, which include centrifugal pumping units, are widely used in the oil refining and petrochemical industries and represent an integral part of technological processes. Therefore, preventing their emergency failure is the most important task, which is solved using vibroacoustic diagnostics. Vibration diagnostic services of technical supervision departments process signals mainly using the spectral method of vibration signal analysis based on the Fourier transform. Along with the undeniable advantages, which include the simplicity of software implementation and the admissibility of optimization for the analysis of many functions of physical processes, this transformation has certain disadvantages. For example, due to the loss of information about the time factor, the idea of the dynamics of changes in the spectral composition of the signal is distorted, which does not allow for a comprehensive analysis of the vibration signal. In this regard, there is a need for additional methods of digital signal processing. In recent years, in the process of research carried out at the Ufa State Petroleum Technological University, it has been proven that a method based on wavelet transformation of vibration signals can be used to assess the technical condition of pumping and compressor equipment. This type of transformation is capable of recognizing not only periodic components of the signal, but also local ones, determining their time and frequency characteristics, and establishing the relationship between the levels of wavelet decomposition and the frequency ranges of wavelet filters. It has been determined that the level of decomposition during the wavelet transform of the signal can be taken as a criterion for clearing the vibration signal of the digital pump from the noise component in the presence of faults such as «imbalance» and «misalignment». Discrete wavelet transform of vibration signals makes it possible to determine amplitude modulation caused by the manifestation of faults of electromagnetic origin and inhomogeneity of the air flow in the gap between the rotor and stator of an electric motor, as well as to identify slowly developing (trend) signals associated with lubrication defects in the motor bearings of centrifugal pumping units. Wavelet patterns store complex information about the signal, however, when several types of faults or defects are combined, it is very difficult to identify the leading one and the degree of its development, especially in the early stages. In this case, the value of the scaling factor can serve as a characteristic of the degree of development of the fault, since it was found that wavelet patterns begin to differ comprehensively when setting the scaling factor of the wavelet transform of signals, starting from a value of 192, confirming the presence of an anomalous signal. Aim of research Increasing the accuracy of assessing the technical condition of centrifugal pumping units by selecting the scaling factor of the basic function of the wavelet transform of vibration signals. Research methods To practically solve the problems, methods and algorithms for digital processing of vibration signals based on the Fourier transform and wavelet transform were used. Results It has been established that for a more accurate assessment of the stage of development of the main faults of the digital pump using the continuous wavelet transform, it is necessary to use a scaling factor of the basic wavelet function equal to 512.