Structure Design And Flow Numerical Simulation Of Supersonic Cyclone In Natural Gas Dehydration

Supersonic hydro-cyclone separation(SSD)is a new technology for natural gas treatment which has a new type of dehydrating device which integrates the functions of condensation and separation.It has a broad research prospect.Because of its obvious advantages,scholars at home and abroad have done a lot of research work on it.However,the main research object is the flow process of axial flow,and the influence of swirling flow is seldom considered.Therefore,it is necessary to carry out a systematic study on the flow characteristics and phase change condensation process in supersonic cyclone,so as to provide theoretical support for the performance improvement of the first cyclone and then expansion supersonic cyclone separator.Based on the investigation of domestic and foreign literature,this paper has done the following work:Firstly,the flow field characteristics and condensation characteristics of a supersonic cyclone were studied methane-water vapor two-component mixed gas as the medium.By means of numerical simulation,the structure of the supersonic nozzle and the hydro-cyclone of the supersonic cyclone are optimized to improve the separation efficiency of the separator.Then,by establishing a 3d numerical model of the hydro-cyclone and solving it,the flow field characteristics of the supersonic hydro-cyclone with different inlet pressure,inlet temperature and pressure loss ratio are analyzed.The results show that the inlet pressure and inlet temperature have little influence on the position of shock wave,but the pressure loss has a great influence.Increasing the pressure loss ratio will cause the position of shock wave to move to the back of the separator.Appropriately increasing the pressure loss ratio can make the gas expand isentropic in the supersonic nozzle to a greater extent,which is conducive to improving the separation efficiency of the supersonic cyclone separator.Finally,the condensation phase model of two-component gas was established,and the condensation flow law of mixed gas in supersonic nozzle was studied.The research shows that,under the same other conditions,lowering the inlet temperature or increasing the inlet pressure can make Wilson point move forward and increase the nucleation rate.Although the back pressure has little effect on the degree of condensation,it will affect the location of the condensation area.Therefore,the condensation degree of the mixed gas can be improved by setting the appropriate inlet temperature and inlet pressure,and the condensation nucleation area can be placed in the effective separation zone by adjusting the back pressure,so as to further improve the separation efficiency of the supersonic cyclone separator.