Supersonic separation technology is a new natural gas sweetening method for the treatment of natural gas with high CO_(2)(carbon dioxide)content.The structures of the Laval nozzle and the supersonic separator were des...Supersonic separation technology is a new natural gas sweetening method for the treatment of natural gas with high CO_(2)(carbon dioxide)content.The structures of the Laval nozzle and the supersonic separator were designed,and the mathematical models of supersonic condensation and swirling separation for CO_(2)-CH4 mixture gas were established.The supersonic condensation characteristics of CO_(2) in natural gas and the separation characteristics of condensed droplets under different inlet pressures were studied.The results show that higher inlet pressure results in a larger droplet radius and higher liquid phase mass fraction;additionally,the influence of centrifugal force is more pronounced,and the separation efficiency and removal efficiency of CO_(2) are higher.When the inlet pressure is 6 and 9 MPa,the liquefaction efficiency at the Laval nozzle outlet increases from 56.90%to 79.97%,and the outlet droplet radius increases from 0.39 to 0.72μm,and the removal efficiency is 31.25%and 54.52%,respectively.The effects of inlet pressures on the removal efficiency of the supersonic separator are complicated and are controlled by the combined effects of liquefaction capacity of the nozzle and centrifugal separation capacity of the swirl vane.展开更多
To improve the separation performance of a supersonic gas separation device for the treatment of gas mixture with a single heavy component, a novel structure with shorter settlement distance was constructed and a meth...To improve the separation performance of a supersonic gas separation device for the treatment of gas mixture with a single heavy component, a novel structure with shorter settlement distance was constructed and a method of droplet enlargement was applied. A series of experiments were carried out in the improved separation device under various conditions, using air-ethanol vapor as the medium and micro water droplets as nucleation cen- ters. The effects of the inlet pressure, temperature and relative humidity, the swirling intensity, and mass flow rate of water on the separation performance were investigated. The separation was improved by increasing the inlet pressure and relative humidity. With the decrease of swirling intensity and mass flow rate of water, the separation efficiency increased first and then decreased. The inlet temperature had a slight effect on the separation. The results showed that the separation performance was effectively improved using the proposed structure and method, and the best separation in this study was obtained with the ethanol removal rate about 55% and dew point depression 27 K. The addition of water had little pollution to the air-ethanol vapor system since the water carry-over rate was within the range of -2 %-0 in most cases.展开更多
In this paper, a dual-throat supersonic separation device with porous wall has been proposed to solve the starting problem of supersonic separator, and the feasibility of the proposed device has been tested numericall...In this paper, a dual-throat supersonic separation device with porous wall has been proposed to solve the starting problem of supersonic separator, and the feasibility of the proposed device has been tested numerically and experimentally. Its flow characteristics have been investigated and the effect of some important parameters includ-ing nozzle pressure ratio(RNP), inlet temperature and swirl intensity were examined. In the device, the supersonic flow state and strong centrifugal acceleration of 240000g can be obtained, which are necessary for the condensation and separation of water vapor. The supersonic region in the device enlarged and the shock wave shifted downstream along with the increasing RNP. The separation performance was improved with the increasing RNP and the inlet temperature. The best separation performance in this study was obtained with ΔTd? 28 K.展开更多
The supersonic nozzle is a new apparatus which can be used to condense and separate water and heavy hydrocarbons from natural gas.The swirling separation of natural gas in the convergent-divergent nozzle was numerical...The supersonic nozzle is a new apparatus which can be used to condense and separate water and heavy hydrocarbons from natural gas.The swirling separation of natural gas in the convergent-divergent nozzle was numerically simulated based on a new design which incorporates a central body. Axial distribution of the main parameters of gas flow was investigated,while the basic parameters of gas flow were obtained as functions of radius at the nozzle exit.The effect of the nozzle geometry on the swirling separation was analyzed.The numerical results show that water and heavy hydrocarbons can be condensed and separated from natural gas under the combined effect of the low temperature(-80℃) and the centrifugal field(482,400g,g is the acceleration of gravity).The gas dynamic parameters are uniformly distributed correspondingly in the radial central region of the channel,for example the distribution range of the static temperature and the centrifugal acceleration are from -80 to -55℃and 220,000g to 500,000g,respectively,which would create good conditions for the cyclone separation of the liquids.However,high gradients of gas dynamic parameters near the channel walls may impair the process of separation.The geometry of the nozzle has a great influence on the separation performance. Increasing the nozzle convergent angle can improve the separation efficiency.The swirling natural gas can be well separated when the divergent angle takes values from 4°to 12°in the convergent-divergent nozzle.展开更多
A new type of dehydration unit for natural gas was briefly described and its basic structure and working principles were presented. An indoor test rig for testing the unit performance was set up and the experimental r...A new type of dehydration unit for natural gas was briefly described and its basic structure and working principles were presented. An indoor test rig for testing the unit performance was set up and the experimental results were given. The results showed that the unit could attain a maximum dew point depression of about 20℃ without any need of external mechanical power and chemicals. The pressure loss ratio, shock wave and the flow rate had great influence on the dehydration characteristics. From the systematic analysis of the factors that affect the dehydration efficiency of the unit, the suggestions for improving the unit are put forward.展开更多
The coherent structures of flow over a double elliptic surface are experimentally investigated in a supersonic low- noise wind tunnel at Mach number 3 using nano-tracer planar laser scattering (NPLS) and particle im...The coherent structures of flow over a double elliptic surface are experimentally investigated in a supersonic low- noise wind tunnel at Mach number 3 using nano-tracer planar laser scattering (NPLS) and particle image velocimetry (PIV) techniques. High spatiotemporal resolution images and velocity fields of both laminar and turbulent inflows over the test model are captured. Based on the time-correlation images, the spatial and temporal evolutionary characteristics of the coherent structures are investigated. The flow structures in the NPLS images are in good agreement with the velocity fluctuation fields by PIV. From statistically significant ensembles, spatial correlation analysis of both cases is performed to quantify the mean size and the orientation of coherent structures. The results indicate that the mean structure is elliptical in shape and the structural angles in the separated region of laminar inflow are slightly smaller than that of turbulent inflow. Moreover, the structural angles of both cases increase with their distance away from the wall.展开更多
A mathematical model for phase equilibrium prediction of multi-component gas separation process inside a supersonic separator is established and an efficient numerical solution method is designed. The model and the nu...A mathematical model for phase equilibrium prediction of multi-component gas separation process inside a supersonic separator is established and an efficient numerical solution method is designed. The model and the numerical method are then used to predict the phase equilibrium characteristics and the separation performance of a field test natural gas supersonic purification separator. The predicted results are generally in good agreement with the field test measurements, which proves that the phase equilibrium model and the solution method are both reliable and accurate, and can be used for the prediction of the vapor and liquid phase equilibrium and the separation performance and the configuration optimization of supersonic separator.展开更多
基金supported by the Research Project of Technical Inspection Center of Sinopec Shengli Oilfield Company“Research of Energy Flow Optimization Analysis and Application Technology of Oilfield Production System”and the Natural Science Foundation of Shandong Province(Grant No.ZR2021QE030).
文摘Supersonic separation technology is a new natural gas sweetening method for the treatment of natural gas with high CO_(2)(carbon dioxide)content.The structures of the Laval nozzle and the supersonic separator were designed,and the mathematical models of supersonic condensation and swirling separation for CO_(2)-CH4 mixture gas were established.The supersonic condensation characteristics of CO_(2) in natural gas and the separation characteristics of condensed droplets under different inlet pressures were studied.The results show that higher inlet pressure results in a larger droplet radius and higher liquid phase mass fraction;additionally,the influence of centrifugal force is more pronounced,and the separation efficiency and removal efficiency of CO_(2) are higher.When the inlet pressure is 6 and 9 MPa,the liquefaction efficiency at the Laval nozzle outlet increases from 56.90%to 79.97%,and the outlet droplet radius increases from 0.39 to 0.72μm,and the removal efficiency is 31.25%and 54.52%,respectively.The effects of inlet pressures on the removal efficiency of the supersonic separator are complicated and are controlled by the combined effects of liquefaction capacity of the nozzle and centrifugal separation capacity of the swirl vane.
基金Supported by the Natural Science Foundation of Liaoning Province, China (20052193) and Ph.D. Programs Foundation of Ministry of Education o f China (20070141045).
文摘To improve the separation performance of a supersonic gas separation device for the treatment of gas mixture with a single heavy component, a novel structure with shorter settlement distance was constructed and a method of droplet enlargement was applied. A series of experiments were carried out in the improved separation device under various conditions, using air-ethanol vapor as the medium and micro water droplets as nucleation cen- ters. The effects of the inlet pressure, temperature and relative humidity, the swirling intensity, and mass flow rate of water on the separation performance were investigated. The separation was improved by increasing the inlet pressure and relative humidity. With the decrease of swirling intensity and mass flow rate of water, the separation efficiency increased first and then decreased. The inlet temperature had a slight effect on the separation. The results showed that the separation performance was effectively improved using the proposed structure and method, and the best separation in this study was obtained with the ethanol removal rate about 55% and dew point depression 27 K. The addition of water had little pollution to the air-ethanol vapor system since the water carry-over rate was within the range of -2 %-0 in most cases.
文摘In this paper, a dual-throat supersonic separation device with porous wall has been proposed to solve the starting problem of supersonic separator, and the feasibility of the proposed device has been tested numerically and experimentally. Its flow characteristics have been investigated and the effect of some important parameters includ-ing nozzle pressure ratio(RNP), inlet temperature and swirl intensity were examined. In the device, the supersonic flow state and strong centrifugal acceleration of 240000g can be obtained, which are necessary for the condensation and separation of water vapor. The supersonic region in the device enlarged and the shock wave shifted downstream along with the increasing RNP. The separation performance was improved with the increasing RNP and the inlet temperature. The best separation performance in this study was obtained with ΔTd? 28 K.
基金supported by the National High Technology Research and Development Program of China("863 program",No.2007AA09Z301) the National Major Science&Technology Specific Projects(No.2008ZX05017-004)
文摘The supersonic nozzle is a new apparatus which can be used to condense and separate water and heavy hydrocarbons from natural gas.The swirling separation of natural gas in the convergent-divergent nozzle was numerically simulated based on a new design which incorporates a central body. Axial distribution of the main parameters of gas flow was investigated,while the basic parameters of gas flow were obtained as functions of radius at the nozzle exit.The effect of the nozzle geometry on the swirling separation was analyzed.The numerical results show that water and heavy hydrocarbons can be condensed and separated from natural gas under the combined effect of the low temperature(-80℃) and the centrifugal field(482,400g,g is the acceleration of gravity).The gas dynamic parameters are uniformly distributed correspondingly in the radial central region of the channel,for example the distribution range of the static temperature and the centrifugal acceleration are from -80 to -55℃and 220,000g to 500,000g,respectively,which would create good conditions for the cyclone separation of the liquids.However,high gradients of gas dynamic parameters near the channel walls may impair the process of separation.The geometry of the nozzle has a great influence on the separation performance. Increasing the nozzle convergent angle can improve the separation efficiency.The swirling natural gas can be well separated when the divergent angle takes values from 4°to 12°in the convergent-divergent nozzle.
文摘A new type of dehydration unit for natural gas was briefly described and its basic structure and working principles were presented. An indoor test rig for testing the unit performance was set up and the experimental results were given. The results showed that the unit could attain a maximum dew point depression of about 20℃ without any need of external mechanical power and chemicals. The pressure loss ratio, shock wave and the flow rate had great influence on the dehydration characteristics. From the systematic analysis of the factors that affect the dehydration efficiency of the unit, the suggestions for improving the unit are put forward.
基金Project supported by the National Natural Science Foundation of China(Grant No.11172326)the National Basic Research Program of China(Grant No.2009CB724100)the Scientific Research Program of National University of Defense Technology,China(Grant No.0100010112001)
文摘The coherent structures of flow over a double elliptic surface are experimentally investigated in a supersonic low- noise wind tunnel at Mach number 3 using nano-tracer planar laser scattering (NPLS) and particle image velocimetry (PIV) techniques. High spatiotemporal resolution images and velocity fields of both laminar and turbulent inflows over the test model are captured. Based on the time-correlation images, the spatial and temporal evolutionary characteristics of the coherent structures are investigated. The flow structures in the NPLS images are in good agreement with the velocity fluctuation fields by PIV. From statistically significant ensembles, spatial correlation analysis of both cases is performed to quantify the mean size and the orientation of coherent structures. The results indicate that the mean structure is elliptical in shape and the structural angles in the separated region of laminar inflow are slightly smaller than that of turbulent inflow. Moreover, the structural angles of both cases increase with their distance away from the wall.
基金supported by the National Natural Science Foundation of China (Grant No. 50676002)the Research Fund for the Doctoral Program of Higher Education (Grant No. 20040005008)
文摘A mathematical model for phase equilibrium prediction of multi-component gas separation process inside a supersonic separator is established and an efficient numerical solution method is designed. The model and the numerical method are then used to predict the phase equilibrium characteristics and the separation performance of a field test natural gas supersonic purification separator. The predicted results are generally in good agreement with the field test measurements, which proves that the phase equilibrium model and the solution method are both reliable and accurate, and can be used for the prediction of the vapor and liquid phase equilibrium and the separation performance and the configuration optimization of supersonic separator.