On The Effect Of Liquid Properties On The Performance Of Gas-liquid Cylindrical Cyclone

The new generation underwater production system adopts the compact vertical layout concept while the gas-liquid separators applied in this field are faced with harsher requirements.Because of its unique advantages,the Gas-Liquid Cylindrical Cyclone,which is short for GLCC,has a promising prospect in deep-sea rich gas field exploitation.Previous researches on GLCC mostly focus on the situation before liquid carry over happens and there are few studies on GLCC used as a full separator.This paper takes a closer look at the performance of the GLCC whose overflow pipe and underflow pipe are not converged.For further investigations,the author conducts a series of experiments with different liquid media,which comprise flow pattern observation,overflow pressure drop and liquid phase separation efficiency measurements.By introducing the similarity theory into the analysis of experimental data,the characteristics of gas-liquid two-phase flow in GLCC are explored and the empirical model available to predict separation performance is improved.The main findings are listed as follows:?1?A criterion relation of the overflow pressure drop has been established through the dimensionless analysis and the expression is Eu_g=f?Re_l,Re_g,Fr_g,K_A,D/d_g,K_F?.This expression contains the influences of gas and liquid flowrates,the convergent nozzle sizes,the diameter of the overflow pipe and physical properties of liquid.Thus,it can be more comprehensive to reflect the overflow pressure drop and has a high calculation accuracy.?2?The dimensionless numbers which affect the process of liquid carry over are preliminarily obtained by means of equation analysis,then the original numbers are processed based on the researches of droplet breakup.The author proposes to represent the starting point curve of liquid carry over with the dimensionless parameters coordinate system N_vg and N_vl.Based on the data of glycerine solution with three different concentrations,the dimensionless function equation of LCO starting point curve is derived.?3?Research on the efficiency of liquid separation is converted to study on liquid carry over rate.According to the researches on the liquid carrying problem in vertical pipe two-phase annular flow,the dimensionless number S(S=We^0.5R?^0.6)is introduced to reflect the change rule of liquid carry over rate,and a hyperbolic tangent fuction is also used to describe the curve.Finally,the author establishes two empirical formulae under annular flow and churn flow.When calculating liquid separation efficiency using the above formulae,the relative errors between computational value and experimental data will fall respectively within the scope of±0.5%and±1%,which can meet the demand of engineering requirements.