| Oil is one of the most important energy sources in today’s human society,and it is the most important driving force of the national industrial pillar industry.It is called "the blood of industry." The world’s offshore oil resources are very rich,and marine oil and gas production has continued to increase in recent years,alleviating the dilemma caused by the shortage of land oil resources.Offshore platform oil well production fluids are generally not directly usable.They are a mixture of crude oil,natural gas,water and sediment.The three-phase separator is usually the first equipment on the production platform to treat well fluids.At present,the existing three-phase separators at home and abroad can achieve high separation processing precision under special circumstances,but the general applicability is poor;In addition,the three-phase separator does not have a valid unified international design standard,and the design theory is not perfect,resulting in the performance of separation and resistance to fluctuations are not very satisfactory.Therefore,it is necessary to further study the design process of the separator and the internal flow field,which is essential for the improvement of separation efficiency.In this paper,the horizontal gravity three-phase separator under specific processing conditions is taken as the research object.To initially design the body size and pressure vessel structure,and adopt CFD related theories and research methods.Simulation of the flow field of the separator with internal components with different structural types and dimensional parameters was simulated using Fluent software.Through the analysis results,the optimal component type and component parameters that can achieve higher flow field stability and oil-water separation efficiency are determined.The main results are as follows:(1)Through the study of the structure and working principle of the three-phase separator,the "half-full method" is used to design the separator based on the gas-liquid separation and oil-water separation process,which provides specific dimensional data for the simulation study.The pressure vessel structure of the separator is designed based on the ASME standard,including the determination of suitable design parameters,container weight estimation,and vessel wall thickness determination.(2)Fluent software was used to simulate the flow performance and separation performance of the internal flow field of the inlet,rectifier and poly-structure separatorswith different structural types and component parameters.Through the analysis of the simulation results,the paper finds that the separator with the lower-hole box-type inlet member is the best in suppressing the inlet turbulence and stabilizing the flow field.And the gravity energy dissipation and water washing effect are also beneficial to the subsequent oil droplet coalescence and sedimentation.(3)Among the five kinds of rectifying members studied,the rectifying effect of the Square plate type rectifying member is the best,the average axial flow index is the highest,keeping above 0.9,producing the least eddy current,and increasing the length of the member will improve the rectifying performance of the cylindrical type.At the same time,the flow performance of separator affects the separation performance.(4)The poly-structured parts with a plate spacing of 10 mm and a plate inclination angle of 45°can realize larger oil droplet floating speed,longer liquid phase residence time and better oil film coalescence and lifting conditions.And its oil and water separation is the best.The research work in this paper provides a certain reference for the research and development of new high-efficiency separators. |
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