Experimental Study On Response Characteristics Of Gas-water Slug Flow In The Inclined Pipe

Multiphase flow pipeline transportation is the most common way of transportation in the production of natural gas industry.The occurrence of slug flow in the process of transportation is harmful to the production of the oil fields.The transient slug flow causes the pipeline corrosion.The impact of equipment will shorten the service life of equipment.and affects the downstream separation and gas system work.Therefore,it is very important to study the slug flow.Based on the multiphase flow loop experimental platform of Xi’anShiyou University,the response characteristics of slug flow in the inclined pipes are studied.The main contents are as follows:The pressure response characteristics and pressure difference response characteristics of the gas water two phase slug flow in the inclined pipe are studied in this paper.The results show that the fluctuation signals of pressure and pressure difference in the inclined pipe show periodic fluctuation characteristics.Liquid superficial velocity affects the variation of pressure and pressure fluctuation cycle.When changing the tilt angle,the pressure of the inclined test section decreases,and the fluctuation frequency of pressure difference decreases.The probability density of pressure fluctuation signal varies with the inclination angle,and the distribution pattern is multimodal.With the change of liquid superficial velocity,there are many complex distributions.The dispersion of pressure signal probability density distribution decreases with the increase of tilt angle,and increases with the increase of liquid superficial velocity from single peak to multimodal distribution.The distribution of probability density of pressure fluctuation is unimodal distribution.The dispersion of pressure probability density is not obvious with increasing tilt angle.The dispersion increase first and then decreases with the increase of liquid superficial velocity.When adjusting the tilt angle of experimental pipe or changingsuperficial gas or liquid velocity,the probability density function of pressure difference distribution is unimodal.The amplitude of the pressure difference power spectral density varies with the change of the angle of the inclined pipe and thesuperficial gas or liquid velocity,and its amplitude changes in a certain frequency range.Liquid holdup of slug flow in pipe is measured by digital image processing technology,and the liquid holdup of slug flow in inclined pipe is characterized by no obvious fluctuation cycle.The Liquid holdup of liquid slug and liquid film increases with the increase of liquid superficial velocity.The probability density distribution of the liquid holdup in the inclined pipe is single peak,and the probability density distribution of the liquid-phase rate of liquid holdup is a complex form of single peak and multi peak.Increasing the liquid superficial velocity,the probability density distribution of liquid holdup shows a complex form of unimodal and multimodal.