Study On Condensation And Separation Of Wet Natural Gas In Supersonic Nozzle

With the increasing production and use of natural gas,some traditional technology of natural gas impurity removal has been unable to meet the needs of the continuous development of natural gas market.Natural gas is a kind of substance which contains many kinds of components.Its components,such as water vapor and carbon dioxide,will have a great impact on the use and safe transportation of natural gas.Under this background,using supersonic nozzle technology to remove impurities from natural gas has become the focus of relevant scholars’ research.This technology provides a new idea for natural gas removal by using the characteristics of supersonic natural gas expansion,cooling and condensation,as well as swirl separation,and accurately mastering the expansion,cooling and condensation law of supersonic natural gas is the basis and key to use this technology.Based on this,this paper reviews the research status of related topics at home and abroad,introduces the supersonic natural gas condensation flow parameters,determines the gas condensation nucleation model,droplet growth model and wet natural gas flow model used in the numerical simulation study,designs and verifies the supersonic nozzle structure and grid number required in the study,and compiles the UDF calculation program.On the basis of this,methane carbon dioxide and methane water vapor two-component gas are used as the research medium of supersonic wet natural gas,and two sets of numerical simulation studies are carried out,focusing on the variation of temperature,pressure,nucleation rate,humidity and nucleation rate with the distance X of the nozzle after the gas enters the nozzle,and the effects of different temperature,pressure and gas component proportion on the liquid are explored The effect of drop number,humidity and nucleation rate.The conclusion is as follows:(1)The gas temperature remains unchanged for a certain distance.With the increase of the distance from the x-axis of the nozzle,the temperature begins to decrease gradually.The temperature decreases to the minimum value at a certain distance from the throat,then increases gradually,rises to the maximum value at a certain distance from the throat,and then decreases gradually.The gas pressure remains unchanged for a certain distance.With the increase of the distance from the x-axis of the nozzle,the pressure begins to decrease gradually The pressure curve rises at a certain distance from the throat,and decreases with the increase of the distance from the x-axis of the nozzle;(2)the number,humidity and nucleation rate of droplets from the beginning of gas entering the nozzle to a certain distance from thethroat do not increase.With the increase of the distance from the x-axis of the nozzle,the number,humidity and nucleation rate of droplets begin to increase,and the number of droplets begins to increase The number of droplets and the location of droplets increase and move backward with the increase of temperature,decrease and move forward with the increase of pressure,decrease and move forward with the increase of mole fraction of condensable gas component,decrease and move backward with the increase of temperature,increase and move forward with the increase of pressure,The peak value of nucleation rate and the position of nucleation rate increase and move backward with the increase of temperature,decrease and move forward with the increase of pressure,and decrease and move forward with the increase of the mole fraction of condensable gas.In order to provide a way for the purification of natural gas with high water content and high carbon dioxide content,and lay a foundation for the subsequent study of supersonic condensation and separation of methane carbon dioxide water vapor three-component gas.