Numerical simulation of two–phase separation in a small diameter ratio T‐junction

Abstract

The utilization of T‐junctions for flow division is quite common in industries. Due to the phenomena known as multiphase maldistribution, occurring in a T‐junction, they are often used as partial phase separators for reducing the work load on phase separation devices in oil and gas platforms. Previous literature says that reducing the diameter ratio of the T‐junction improves the two‐phase separation, however it was also reported that reducing the diameter ratio too much has a negative effect on two‐phase separation. To test this, a numerical study was performed to see the two‐phase stratified flow separation in 1, 0.6 and 0.167 diameter ratio T‐junctions. Furthermore, the impact of air superficial velocity on phase maldistribution at the junction is also considered. The T‐junctions with diameter ratios 1 and 0.6 were just used for the validation of present model, by comparing the obtained numerical results with previous experimental data. While, 0.167 diameter ratio T‐junction is the one for which the actual analysis was performed. It is concluded that an increase in air superficial velocity aids liquid carryover, whereas liquid carryover is very sensitive to side arm extraction rates in a very small diameter ratio T‐junction.

Numerical investigation of liquid‐liquid two‐phase separation and pressure drop characteristics in T‐junctions

“…Air-water 0.178-1.4 0.094-0.84 SW, SL Numerical Pao et al [9] 45, −90 0 200 1.0, 0.75, 0.5 Air-water 5.6-14.4 0.32-4.5 a Eulerian model Sam et al [10] −90, 0, 90 0 152.4 0.167 Gas-oil 1.0-4.2 1.08 a 1D model Pao et al [11] 90 0 127 1.0, 0.6, 0.167 Air-water 0.816-12.0 0.0283-0.434 S Eulerian model Lu et al [12]…”

“…In recent years, certain numerical studies on phase separation have been performed. [9][10][11][12] Pao et al [9] determined the effects of the diameter ratio, initial inlet gas saturation, and gas density on phase separation in different directions of the branch. Sam et al [10] investigated the operating pressure as the most important parameter for phase separation using a 1D model.…”

“…Sam et al [10] investigated the operating pressure as the most important parameter for phase separation using a 1D model. Pao et al [11] reported that the liquid carryover was directly proportional to the superficial velocity of air. Lu et al [12] observed that an increase in the inlet mass flux improved the phase separation using R22 and R134a as working fluids.…”

Experimental investigation of multiphase separation in different flow regimes through T-junction with an expander section

“…For the geometry alone there are eight parameters which are required, i.e., the diameter of main, run and branch arm, the length of main and branch arm, orientation angles of main, run and branch arm [13,14]. A lot of research literature is available on altering the diameter ratio [15,16], branch orientation [17], inlet flow regimes like stratified, stratified-wavy, and slug flow [18][19][20].…”