The Numerical Simulation Of Gas Two-phase Flow Under Low Temperature In Supersonic Separator

According to the distribution of domestic natural gas resources,small gas liquefaction device has good development prospect and development trend.This article increases the understanding of liquefied natural gas process in the supersonic separator.At the same time,the analysis of factors affecting the liquefaction efficiency is another focus in the study of it.At first,this paper designs a process of natural gas liquefaction technology in the supersonic expansion equivalent entropy state by using HYSYS software.Through the assumption of the ideal state,this paper calculates the change of the distribution of liquid phase in the supersonic swirling separator under the entrance condition of 180 K,2000 KPa,and it is concluded that temperature,pressure,gas phase fraction,enthalpy and velocity with the change of relative cross-sectional area.On the basis of the calculation results,it is also concluded that lower inlet temperature and lower inlet pressure can improve the efficiency of the natural gas liquefaction by using the XY graph analysis.Then the paper uses Fluent software to carry on the numerical simulation of natural gas liquefaction process,through the verification of the numerical simulation method,the model set,the grid division,and the parameter setting.Not only the influence of inlet parameters on the liquefaction efficiency is analyzed,but also it is concluded that the lower pressure after expansion,the greater the nozzle exit area and the change of export structure parameters such as the smaller diameter can improve the liquefaction efficiency.And it is concluded that the numerical simulation of liquefaction efficiency is lower than the theoretical calculation results by comparing the theoretical calculation results and the Fluent software simulation calculation results,and the biggest gap of the calculation results of the two methods is 26.8%,but both are less than 0.2.Finally through the analysis of the boundary layer effect and the understanding of the reducing of the droplet nucleation rate,it is concluded that they caused the actual simulation calculation results are less than ideal results slightly.