Low-liquid Loading Gas-liquid Two Phase Flow In Venturi Tube

Because of its simple structure,wide range of applications,easy maintenance,and standard parts for easy production,differential pressure meter is widely used in petrochemical industry.Among them,the venturimeter has the advantages of shorter upstream anddownstream straight sections,less influence by the flow pattern and relatively small pressure loss is favored by multi-phase flow measurement and is widely used in multi-phase flow measurement devices.When low-liquid loading gas-liquid two phase flow through the Venturi tube,the presence of a small amount of liquid phase leads to an increase in the pressure drop,resulting in Over-Reading.Until now,many scholars at home and abroad have done a lot of research on venturi tubes in the measurement of low-liquid loading gas-liquid two phase flow,and have established many Over-Reading models.One of these Over-Reading models is derived from the measurement mechanism and the formula is deduced;the other is based on the experimental data of low pressure and small pipe diameters to fit the data.However,these models generally have the following problems:First,the true flow characteristics in the venturi are neglected;second,the applicability of each measurement imaginary height model under actual high pressure operating conditions has not been verified.In order to solve the above problems,the method of Computational Fluid Dynamics(CFD)was used in this paper.The Fluent software was used to simulate low-liquid loading gas-liquid two phase flow in the venturi,using standard k-? model and discrete phase model(DPM),Overcome the limitation of experimental conditions,then the flow field distribution,static pressure distribution,and droplet concentration distribution of the low-liquid loading gas-liquid two phase flow in the venturi were obtained in a relatively short period of time;The Over-Reading increases with the increase of the flow rate of gas?Lockhart-Martinelli parameter,and decreases with the increase of pressure.The simulation work conditions were expanded and the numerical studies under high-pressure conditions were completed to verify the applicability of the Over-Reading models under high pressure,give the ranking of the use performance of each Over-Reading models under high pressure,and found that the Over-Reading model with the highest performance under high pressure is the ISO model.The results of this study can provide guarantee for safe production,provide basis for application value.