On The Effect Of Liquid Medium On Flow Pattern And Performance Of Dual-inlet Gas-liquid Cylindrical Cyclone(GLCC)

The Gas-Liquid Cylindrical Cyclone（GLCC）is a compact separator that combines gravity and centrifugal force,and has obvious advantages in the development of deep-sea oil-gas fields.From the perspective of improving the liquid separation efficiency of the separator,the dual-inlet GLCC has been proposed,but there are few studies on it and insufficient understanding of its internal flow pattern distribution and separation performance is not conducive to expanding to practical applications.The research objects of this paper are the upward dual-inlet GLCC and the downward dual-inlet GLCC with the same two inlets,and the inner diameter of the main cylinder is D=74mm.The influence of liquid medium on the flow pattern and performance of the separator is studied through experiments.The working mediums are air-water,air-glycerin solution,and air-T55 heat transfer oil respectively,and the experimental working conditions range from80 m3/h to 200 m3/h for air flow and 0.6 m3/h to 3.0 m3/h for liquid flow.The main research results are as follows:With the help of high-speed camera,the characteristics and distribution of dual-inlet GLCC internal flow pattern are summarized,and the gas-liquid flow pattern maps in the inclined inlet pipe and the upper cylinder of the dual-inlet GLCC are obtained.Focus on analyzing the influence of different liquid mediums on the flow pattern,using the gas Reynolds number Re_g,gas-liquid density ratio R_ρ,dimensionless liquid velocity N_l and liquid film surface fluctuation number K_F,the dimensionless gas characteristic number N_g^*（N_g^*=Re_gR_ρ）and the dimensionless liquid characteristic number N_l^*(N_l^*=N_lK_F^1/3)to comprehensively characterize the influence of the physical property parameters of the liquid medium and the experimental operating parameters.Furthermore,for the downward dual-inlet GLCC,taking the characteristic numbers N_g^*and lg（N_l^*）as the coordinates,the flow pattern map in upper cylinder of GLCC with different liquid mediums is drawn,and the flow pattern transition discriminant based on the above characteristic numbers is established.At the same time,based on the liquid film flow pattern in upper cylinder,the liquid carrying-over phenomenon in GLCC is analyzed,and it is determined that LCO occurs when the flow pattern changes from the swirling annular flow to the churn flow.Then the flow pattern transition discriminant is also the LCO starting point equation,and the error is less than 15%compared with the experimental value,so the envelope of the normal operation of the GLCC can be determined.For the performance of liquid separation,the liquid separation efficiency and overflow pressure drop are measured experimentally,and the effects of different liquid mediums on the separation efficiency and overflow pressure drop are determined.Based on the characteristic numbers N_g^*and N_l^*,a quasi-number relationship to characterize the overflow pressure drop is established,and the error between the calculated value and the experimental value is basically within 20%.