Experimental Study On Gas Phase Separation Performance Of Gas-Liquid Cylindrical Cyclone

The gradual development of deep-sea oil and gas fields has promoted the application of oil and gas separation equipment.Submarine oil and gas separation can reduce the cost of the oil exploitation,reduce hydrate formation and extend transportation distance.The traditional volumetric gas-liquid separator is limited in deep-sea environment due to its bulky volume and high manufacturing cost.Gas-liquid Cylindrical Cyclone(GLCC)has the characteristics of compact structure and easy operation,which shows good industrial application prospects.However,the internal flow pattern of GLCC is complex and changeable,and there is still a lack of methods to accurately predict the separation performance.This paper focuses on the gas-liquid separation performance of GLCC.The effects of different inlet nozzle structures are studied by using fast shut-off valve method.Three different gas-liquid two-phase flow systems,air-water,air-T55 conduction oil and airglycerol solution,are used to study the effect of liquid medium changes on the gas holdup of the liquid exit tube of GLCC.The main conclusions are as follows:(1)For air-water two-phase system,the flow pattern of the lower cylinder can be divided into four types: non-gas core,unstable gas core,stable gas core and concave gas core.When the liquid medium is T55 conduction oil or glycerol solution,the flow pattern can not be distinguished because of its color and the foaming phenomenon of glycerol solution.(2)The nozzle structure affects the velocity of the gas-liquid phase entering the GLCC.Under the 3# nozzle with the smallest cross-section size,the gas content of liquid outlet pipe increases first and then decreases.When the liquid velocity entering the separator cylinder increases to a certain extent,the swirl intensity increases,the separation ability of bubbles increases,and the number of bubbles coming out begins to decrease.(3)The dimensionless number S is proposed to reflect the variation of gas void fraction in liquid outlet pipe for water and T55 conduction oil.The hyperbolic tangent function is used to correlate the gas void fraction in liquid outlet pipe.For glycerol solution,the dimensionless number S* is introduced to describe the variation of gas void raction in liquid outlet pipe.The maximum errors of the two formulas for predicting the gas void fraction of liquid outlet pipes are 15% and 10% respectively,which meet the needs of industrial applications.