Study On Separation Performance Of Multiphase Fluid In A New Type Of Cyclone Desander

At present,fracturing technology is used in the exploitation of oil and gas fields to increase production,but it is also accompanied by a large amount of liquid and solid impurities that need to be recovered and reprocessed.For solving this kind of problem,single-cone cyclone desander and double-cone cyclone desander are designed,but the gas collection and separation performance need to be improved.In order to continue to improve the gas collection and separation performance,the inner overflow pipe was added to the double-cone cyclone desander,and FLUENT was used for the single-cone cyclone desander,double-cone cyclone desander and double-cone double-overflow pipe cyclone desander.Numerically simulating three cyclone desanders and comparing their flow field characteristics and separation performance.The main findings are as follows:(1)First of all,the velocity field and pressure field of the three kinds of desanders with different structures are simulated.After comparison,it is found that the double-cone double-overflow pipe cyclone desander has more stable distribution in both the velocity field and the pressure field.Laying a good foundation for separation work.(2)Secondly,a comparative analysis of the mass flow of gas and liquid at the overflow and underflow ports of the three desander models was carried out,and it is found that the double-cone double-overflow pipe cyclone desander can collect more gas and recycle liquid well,which improving the economy and protecting environment.(3)Thirdly,on the basis of the three models of gas-liquid flow field,the discrete phase model is added to simulate its gas-liquid-solid three-phase flow field.It is found that the double-cone double-overflow cyclone desander also has good separation of particles with smaller diameters,and when the particles are discharged with a large amount of liquid along the outer overflow pipe,it will not affect the gas in the inner overflow pipe by analysing the trajectory of a single particle of different diameters,the trajectory of particles at different injection positions,and the trajectory of particle groups.It is improved in a disguised way that separation efficiency.(4)Next,the diameter and length of the internal overflow pipe structural parameters were changed,four models were simulated respectively,and the influence of the diameter and length of the internal overflow pipe on its flow field and separation performance was analyzed.Select the optimal structural parameters.(5)Finally,mainly analysing the influence of inlet speed and inlet pressure on its separation performance and obtain the most suitable parameter values by optimizing the operating parameters of the most optimal mode.The above research provides a theoretical basis and reference for further analysis of the separation mechanism,separation characteristics and structure optimization of the cyclone desander,and provides a reference for the design of a high-efficiency cyclone desander in engineering.