Study On The Structure And Oil-gas Separation Efficiency Of Gas-liquid Cylindrical Cyclone Separator

As a new type of gas-liquid separator,the gas-liquid cylindrical cyclone separator(GLCC)has the advantages of high separation efficiency and small footprint.However,in practical application,the gas-liquid entrainment often occurs,which affects the separation performance.In this paper,the structure improvement of the gas-liquid cylindrical cyclone separator is studied by numerical simulation.According to the literature data,the GLCC geometric model is established,and the hexahedron unstructured mesh is divided.The RNG-turbulence model and the Mixture multiphase flow model are used.The distribution of tangential velocity and axial velocity accords with the characteristics of combined vortex in cyclone separator.Comparing the simulation results with the experimental results,the minimum error is9.1%and the maximum error is 13.0%.It is proved that the numerical simulation method is reasonable.The conventional GLCC and the the improved GLCC with cone and cone frustum at the bottom are simulated numerically.The result shows that the separation efficiency increases from 70.2%to 72.4%and 74.1%,and the pressure drop reduces from 0.0212 Mpa to 0.0205 Mpa and 0.0206 MPa.The effects of five structural factors on the gas-liquid separation efficiency and pressure drop are studied by orthogonal test,such as the diameter of overflow vent,the diameter of bottom outlet,the inlet height,cone frustum bottom radius and the height of the cone frustum.According to the extreme difference analysis of orthogonal results,it is determined that the influence of various factors on the separation efficiency index is in the order of overflow diameter,bottom flow diameter,height of the cone frustum,inlet height and cone frustum bottom radius.The influence on the separation efficiency index is in the order of bottom flow diameter,height of the cone frustum,cone frustum bottom radius,overflow diameter and inlet height.By using the comprehensive equilibrium method,the optimal structure combination in the scope of this study is obtained.The effects of fluid physical properties and operational parameters on the separation performance of GLCC are studied.The results show that when the inlet flow rate increases from 1 m~3/h to 11 m~3/h,the separation efficiency increases from59.9%to 83.0%,and the pressure drop increases from 8.50×10~-44 MPa to 0.101 MPa.The larger the inlet flow rate,the better the separation effect is,but the pressure loss increases.When the inlet gas content increases from 0.1 to 0.7,the separation efficiency increases from 83%to 86.7%first,and then decreases to 70.6%.The separation efficiency is the best when the gas content was 0.3.With the increase of inlet gas content,the pressure drop decreases from 0.0368 MPa to 0.0104 MPa.When the liquid viscosity increases from 1 mPa·s to 50 mPa·s,the separation efficiency decreases from 85.7%to 56.9%,and the pressure drop increases from 0.0961 MPa to0.1180 MPa.The higher the liquid viscosity,the worse the gas-liquid separation efficiency and the greater the pressure loss.So the cylindrical cyclone separator is not suitable for gas-liquid separation of high viscosity oil.When the bubble diameter increases from 100?m to 700?m,the separation efficiency increases from 55.3%to94.0%,and the pressure drop increases from 0.0141 MPa to 0.0134 MPa,which indicates that the bigger the bubble diameter,the better the separation effect.