Study On The Influence Of Impurity Characteristics On The Laws Of Product Oil Carried With Particles

In this paper,the deposition-movement law of the particles in the product oil pipeline is studied by using new designed and established the experimental loop of product oil carrying water and impurity and the DEM-CFD coupling method.The movement phenomena of two kinds of particles with different particle size were analyzed experimentally.The particle deposition length,deposition quality and clear time of different particle addition,different pipe inclination angle and different mixing ratio were compared.And the difference of the migration parameters between the mixed particles and the single particles was analyzed.According to the terms proposed by scholars,the concept of three critical velocities in the process of particle movement is redefined,and the results show that the inclination angle and particle size have a great influence on the critical velocity.In order to obtain the required friction coefficient,the static friction force between the particles and the particle-pipe was measured by a self assembled instrument.With no bottom cylinder method of particle accumulation experiments in different planes,adopt the method of image processing,measure the angle of repose and particle stacking height range,then through the DEM software to simulate the packing process,using the method of parameter calibration to identify the rolling friction coefficient is consistent with the experimental conditions between particles and the pipeline between the particles.Based on the above parameters,the climatic critical velocity of the two kinds of single particles under different inclination is simulated.The results are consistent with the experimental,which verifies the correctness of the model selection and the reliability of the parameter settings.Based on the DEM-CFD method,the movement of impurities in product oil was simulated on the basis of the verified model.The process of particle movement is described.The reason of particle sorting in different particle size is analyzed from the view of particle force.When the climatic critical velocity is the same,analysis each part of the mixed particles of potential energy and kinetic energy in the pipeline and degree of sort phenomenon.The effects of single particle friction coefficient,particle shape,particle density,pipe diameter,pipe curvature radius,oil viscosity and oil density on the climbing critical velocity were studied by using the control variable method,and compare the deposition location of flow field variation.