Study On The Acoustic Characteristics And The Detection Methods For Fluid Dynamic Noise Of Oil Transfer Pump Unit

The oil pump unit is usually composed of a three-phase asynchronous motor and a centrifugal pump,which will inevitably produce vibration and noise in the working process.The operating noise of the unit contains the information of the equipment running state,which can be used for equipment health management and fault diagnosis.At present,there are many researches on the hydrodynamic noise of centrifugal pump,but the hydrodynamic noise of oil-water two-phase flow is relatively less studied.In order to deeply study the generation mechanism of fluid dynamic noise of oil pump unit,and establish the relationship between the running state of centrifugal pump and fluid dynamic noise,this paper studies the acoustic characteristics and detection methods of fluid dynamic noise of oil pump unit.In this paper,the acoustic characteristics and detection methods of hydrodynamic noise in oil pump sets are studied from four aspects.Firstly,according to the internal structure characteristics of the centrifugal pump,the relationship between the noise generation and the operating state of each component is analyzed to determine the generation mechanism and characteristics of the hydrodynamic noise of the pump unit in the fault-free state of the centrifugal pump.Secondly,study the cause of cavitation fault and analyze the variation mechanism and morphological difference of hydrodynamic noise caused by cavitation fault,determine the characteristics of cavitation fault noise;Thirdly,RNG k-ε turbulence model is built according to the characteristics of crude oil fluid.Fluent simulation software is used to simulate and analyze the fluid inside the volute to explore the distribution characteristics of the fluid pressure field flow state inside the volute.Fourthly,set an effective sampling point outside the centrifugal pump volute to sample the overall operation noise of the oil transmission pump set,and extract the hydrodynamic noise by using the single-frequency information extraction technology,and verify the spectrum distribution characteristics of hydrodynamic noise by experiments.The simulation results of hydrodynamic noise of centrifugal pump show that with the increase of water holding capacity of crude oil,the density of crude oil fluid increases and the viscosity decreases.Under the condition of maintaining the design flow rate,the pressure at the corresponding point of the flow field in the volute increases with the increase of the water holdup of crude oil;The pressure difference at the diaphragm of the flow field in the volute of centrifugal pump is the largest.The experimental results of hydrodynamic noise of oil-water two-phase flow show that,the maximum relative error between the noise frequency measured at each sampling point and the theoretical frequency value is 0.88%,which is also in good agreement with the simulation results.The conclusion of this study provides an important basis for the power noise monitoring of the centrifugal pump.