Numerical Simulation Of Oil-Water Separation Process In Combined Three-Phase Separator

Used for separating gas,oil and water under the gravity action,three-phase separators possesses broad application in crude oil processing technology due to its simple construction,few occupied space and high separation efficiency.Based on the commercial software Fluent,the separation process of oil-water in combined three-phase separator is simulated as well as the effects of different components in the separator on oil-water separation.Results indicates that the flow field of separation space is steady having no secondary vortex and less back-mixing phenomenon in the separator equipped with the Liquid Distributor inlet component;Besides,the Liquid Distributor inlet component improves separation performance of three-phase separator with better flow parameters such as the standard deviation of axial velocity and forward flow area to total area ratio;Investigation shows that volume fraction of water at oil outlet is reduced,in other words,the Liquid Distributor inlet component has better separation performance than other inlet configurations.When the Liquid Distributor inlet component and the Square Orifice Plate flow regulating component are equipped to the separator,the flow pattern is regulated and back-mixing flow in separation space is restrained effectively.Meaning while,volume fraction of both water at oil outlet and oil at water outlet is decreased inferring that the flow characteristics and separation performance are improved.For the research of coalescence components,numerical simulation is carried on the No-Hole,the Single-Hole and the Double-Hole corrugated plates,respectively.Different from the other two structures,oil and water droplets in the Double-Hole corrugated plates float and settle continuously,forming water film and oil film above and below the plates.Being transformed from single-layer separation to multi-layer separation,movement of oil and water phases is changed from motion of droplet to that of continuous liquid film.Further researches on the separator with corrugated plates are conducted through changing the structural parameters,operation parameters and physical property parameters.Conclusion of the research by studying the parameters' influence on separation effect shows that oil concentration will be enhanced with plate length and spacing increasing among the structural parameters.However,among the operation parameters,the oil concentration is improved with the increasing of entrance oil concentration and the decreasing of entrance velocity.As for the physical property parameters,oil concentration becomes bigger with the decrease of oil density and viscosity and the increase of oil diameter,the corresponding fitting curves being obtained.Effects of these parameters on separation performance should be taken advantage of in the project to improve the separation efficiency.The numerical simulation method adopted in this paper to study the process of oil-water separation in the separator is helpful to investigate the flow field in three-phase separator and the separation process in it.Certain reference value does the paper has to the R&D and optimization of internal components.