Study On Numerical Simulation And Matching Process Of Double Cone Deoiling Hydrocyclone

Hydrocyclone is widely used in the offshore oil mining platform because of its advantages of small size,good separation performance,high reliability of equipment and flexible assembly process.At present,there are various kinds of oil removal hydrocyclones with different structures,and their functions are various.However,in the field of engineering application,the non-size influence factors such as the physical parameters of the oily sewage and the operating parameters of the cyclone are often not determined,so the separation performance can not be fully played.In order to better apply the cyclone to practical production,this paper combines the internal flow field theory,the CFD simulation and the experimental research,and systematically analyzes the non dimensional factors affecting the separation performance of the cyclone and the influence law,and puts forward a set of integrated sewage suitable for the sea oil platform with swirling flow technology as the core.Processing technology.It has a certain guiding significance for enhancing the adaptability of existing hydrocyclones and promoting further development of their supporting technologies.The working principle of the hydraulic hydrocyclone and the basic characteristics of its internal flow field are summarized.The force situation of the dispersed phase oil droplets and the influence of each force on the oil and water separation process are analyzed.The results show that the oil droplets are mainly subjected to the radial force produced by the centrifugal force and the radial pressure gradient in the flow field in the cyclone.The oil-water two phases are separated under their joint action,and there is a Magnus effect in the swirl area inside and outside of the cyclone,which accelerates the separation of oil-water two phases,and the existence of the shear stress causes the rotation deformation of the oil droplets and the crushing and emulsification,and has a direct effect on the separation efficiency of the cyclone.Therefore,we have a qualitative cognition of the flow field in the hydrocyclone theoretically,which lays the foundation for the correct evaluation of numerical simulation and experimental research in the later period.The computational domain model of the double cone hydrocyclone is established by using Gambit software,and the hexahedral mesh is used to discretize it.The turbulence model,the multiphase flow model,the pressure velocity coupling algorithm and the suitable boundary conditions are reasonably selected,and then the strong turbulent field in the cyclone is numerically solved by Fluent.First,the pressure distribution and velocity distribution of the simulated flow field in the hydraulic hydrocyclone are analyzed.The results show that the pressure change gradient of the cylinder section and the large cone section is larger,the energy dissipation is larger,the pressure change of the small cone section is not obvious,and the main work energy is to maintain the original swirling state and prolong the stop.The relationship between the inlet flow rate and the comprehensive separation efficiency of the hydrocyclone under the middle value of different oil droplets is analyzed.The results show that with the increase of the inlet flow,the comprehensive separation efficiency of the swirler is first rising and then decreasing;in general,the overall separation efficiency will increase with the median of the oil droplet diameter.Adding,but the size too large or too small will seriously affect the separation efficiency;the inlet flow and the oil droplet diameter have a close relation,the flow is too large,it will result in the breakage of the oil droplets and two coalescence.Finally,the effect of the shunt ratio on the comprehensive separation efficiency of the hydraulic swirl under different inlet oil concentration is analyzed,and the results are analyzed.It is shown that the separation efficiency increases with the increase of the shunt ratio,and the separation efficiency has a downward trend after the shunt ratio reaches a certain value,because with the increase of the split ratio,the volume of the water flowing out from the overflow will increase,and the comprehensive efficiency will be reduced accordingly.It can be seen that there is a suitable range of shunting ratio for the hydrocyclone,and the smaller the diffluence ratio is,the better the efficiency is.In addition,when the shunt ratio is larger than the inlet concentration,it is possible to achieve the ideal separation efficiency.The above simulation results provide guidance for process test.Experimental research on series technology of several monomer technologies with swirling flow as core is carried out.Based on the WZ12-1-PUQB platform in the South China Sea and CNOOC in the western South China Sea,combined with the numerical simulation results,the principle tests of the cyclones and the coalescer monomers are carried out first,and the optimum operating parameters are defined.Then,the process of the combined process of swirl flow and coalescence is optimized.Finally,after the "swirling flow + coalescing" process is optimized.At the end,the "inclined tube" and "filter" were added to form a complete set of combined process flow,and its excellent technology was verified,which provided technical reference for the subsequent industrial application.