Fault Diagnosis Of Screw Pump Based On Blind Source Separation

As a positive displacement pumps, screw pumps have distinctive features, which havesimple structure than the large oil machinery, such as pumping units. And they have a smallsize, light weight. Now they widely used in petroleum exploration process, especially in thehigh sediment concentration and heavy crude oil extraction process.At last, maneuverabilityof screw pumps is strong. But in the process of oil extraction, pipeline flow affects screwconditions, resulting in pipeline blockage. Screw pumps generate law pressure fluctuationsbecause of hydrodynamic pressure. It affects the life of the screw pump, reduces theefficiency of oil extraction and economic benefits. Therefore, by studying the movement ofthe screw pump and pipeline blockage in unsteady flow conditions. In this paper, the impactof high viscosity fluid flow derived pressure on the screw. Combining with blind separationtechnology, it eventually gives that piping system blocking factor work on the screw in thedifferent conditions.Through the analysis of movement, stress state, fault type and the actual workingconditions of the screw pump, firstly, screw pump model and screw variety of conditions pre—pipe model been established through ProE5.0, based on formation of self—excited by theimpact of the pressure wave. Then through Ansys14.5’s fluent module, it is calculated thathigh viscosity and non—steady—state fluid’s fluctuation pressure of pipe outlet, in the speedof steady situation and cyclical fluctuations as well as pipeline clogging of differentconditions, are obtained. Then stress distribution of screw been obtained by calculatingDynamics module of ANSYS Finally, based on MATLAB and software tools, screw basefunctions, rights of the coefficient matrix and analysis of rubber wear of the screw stator beenobtained by EMD and NMF of blind separation model in different conditions of stress status.Based on anglicizing the simulation of artificial volatility and the reflected wave theory,this paper shows that clogging and blockage position changes mainly affect state of fluid flowfluctuations and fluctuations stress state of screw. However, with the degree and the positionof clogging in the pipe, the screw stress is changed which is that degree of clogging is relatedto the weight of stress fluctuations and blocking position is to the reflecting of wave.Therefore, through screw stress curve, it is possible to effectively estimate the blockingposition and degree of the pipe, and make an analysis of the factors affecting of screw surface stress, further provide assist for the study the mechanism of wear of screw rubber. In otherwords, this has a positive meaning for fault diagnosis of screw system, plugging wells and oilextraction efficiency.