Multiphase Flow Simulation of In-Line Gas-Liquid Separator for Multiphase Metering

2019 ◽  
Author(s):  
Nakyeong Seo ◽  
Nabil Kharoua ◽  
Lyes Khezzar ◽  
Mohamed Alshehhi ◽  
Mahmoud Meribout
Keyword(s):  
Multiphase Flow ◽  
Flow Rate ◽  
Bluff Body ◽  
Recirculation Zone ◽  
Volume Fraction ◽  
Oil Field ◽  
Flow Conditions ◽  
Gulf Region ◽  
Outflow Boundary Condition ◽  
Liquid Separator

Abstract The present study addresses itself to the performance assessment of a novel in-line gas-liquid separator. The separator is developed by FRAMES company under the name of SwirlSep based on the interaction of a swirling flow, generated by an innovative devise called swirl cage, and a hollow conical bluff body designed to deviate the gaseous phase internally.. The separator is intended to be implemented within a multiphase flow metering system in oil field gathering stations in the Gulf region. The study represents a preliminary step among a design process including elaborate lab-scale and filed tests. The flow in the gas-liquid separator is studied using Computational Fluid Dynamics CFD. The Shear Stress Transport (SST) k-ω turbulence and Eulerian-Eulerian multiphase models, under different flow conditions, were used to simulate real flow scenarios. The scenarios were chosen to replicate flow conditions that could exist during the operation of oil wells over their lifetime with the aim to provide guidance for proper control of the separator valves. The fraction of the total flow is prescribed at each outlet, using an outflow boundary condition, to mimic the action of the control valves. At the inlet, the phase velocity and volume fraction were prescribed. The outlet streams and their phase’s content were, then, analyzed together with the distribution of the velocity and concentration fields inside the separator. Velocity and pressure drop were found to increase with the increase of the outflow in one outlet when changing the flow split. Flow control, at the outlets, caused an increase of the oil-in-gas entrainment when trying to minimize gas-in-oil entrainment which is a non-trivial task. The effects of the flow split specified appeared downstream of the conical bluff body only when the inflow conditions were kept constant whereas the flow field remained identical upstream of the cone. A recirculation zone was generated in the annular space downstream of the cone and affected the separator performance considerably. The recirculation zone was due to the effect of the higher flow rate towards the gas outlet and disappeared when the flow rate towards the oil outlet tended to be equal or higher. The phase distribution was identical upstream of the cone and depended on the flow split downstream of the cone. The cases considered served as an assessment of the separator performance under different multiphase flow conditions replicating realistic scenarios.

Evaluation of Multiphase Flow Rate Models for Chokes Under Subcritical Oil/Gas/Water Flow Conditions

2003 ◽  
Vol 18 (03) ◽  
pp. 170-181 ◽  
Author(s):  
R.B. Schüller ◽  
T. Solbakken ◽  
S. Selmer-Olsen
Keyword(s):  
Multiphase Flow ◽  
Water Flow ◽  
Flow Rate ◽  
Flow Conditions ◽  
Oil Gas

Improved Multiphase Flow Rate Models for Chokes in the Algerian HMD Oil Field

2020 ◽  
Author(s):  
Nour ElHouda Tellache ◽  
Meriem Waffa Hassen ◽  
Mohamed Otmanine ◽  
Mohamed Khodja
Keyword(s):  
Multiphase Flow ◽  
Flow Rate ◽  
Oil Field

Evaluation of numerical modelling for a compact down-hole subsea gas-liquid separator for high gas content

2009 ◽  
Vol 49 (1) ◽  
pp. 433
Author(s):  
Shakil Ahmed ◽  
Mohamed Nabil Noui-Mehidi ◽  
Jamal Naser's ◽  
Gerardo Sanchez Soto ◽  
Edson Nakagawa
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Volume Fraction ◽  
Air Flow ◽  
Gas Content ◽  
Water Mixture ◽  
Air Flow Rate ◽  
Flow Rates ◽  
High Efficient ◽  
Liquid Separator

This paper describes the computational fluid dynamics (CFD) modelling of a laboratory scale gas-liquid separator designed for high gas content. The separator consists of two concentric pipes with swirl tube in the annular space between the pipes. The gas-liquid mixture comes tangentially from the side inlet and the system works with a combination of gravity and centrifugal forces to achieve a high-efficient gas-liquid separation. Three dimensional transient multi-phase fluid flows were solved to predict the velocity and volume fraction of each phase. The standard k- turbulence model was used for turbulence closure. The performance of the gas-liquid separator was visually established for a range of gas flow rates (271–495 L/min), with volume fraction (VF) =0.874–0.985 by observing the liquid carry over (LCO) regime where liquid was carried out in the gas stream. The liquid and gas flow rates at which the LCO was observed defines the upper operational range of the separator. Air-water mixture was used in the numerical simulations to keep consistent with the experiments. The pressure between the inlet and exit was validated against the experiments for different air-water flow rate combinations. The values were matched reasonably well for high air flow rate (495 L/min, VF=0.985) but were under-predicted for low air flow rate (271 L/min, VF=0.874). The air and water were mixed upstream of the inlet in the experiments and the pressure was measured at the start of the inlet. In case of numerical simulation the air and water were mixed at the inlet. This might cause the deviation of pressure when the air flow rate was low.

Experimental Investigation on the Influences of Bluff-Body’s Position on Diffusion Flame Structures

2017 ◽  
Author(s):  
Yiheng Tong ◽  
Mao Li ◽  
Jens Klingmann ◽  
Shuang Chen ◽  
Zhongshan Li
Keyword(s):  
Flow Rate ◽  
Diffusion Flame ◽  
High Speed ◽  
Bluff Body ◽  
Recirculation Zone ◽  
Air Flow ◽  
Annular Channel ◽  
Flow Fields ◽  
Flame Stabilization ◽  
Operating Conditions

Effects of the bluff-body’s position on diffusion flame structures and flame instability characteristics were investigated experimentally. A flame regime diagram together with the corresponding flow fields were proposed to evaluate the influences caused by the alternation of bluff-body’s position. The disk shape bluff-body was placed 10 mm downstream or at the same height with the annular channel exit. The bulk velocity of the annular air flow varied from 0 to 8.6m/s while the central jet fuel velocity ranged from 0 to 30m/s. Various flame patterns including the recirculation zone flame, the stable diffusion jet flame, split-flashing flame and lifted flame were observed and recorded with a high speed camera. It is found that the flame has approximately the same patterns with different bluff-body’s positions, except for cases with high air flow rate (Ua > 6.8m/s) and low fuel flow rate (Uj < 5m/s). Under that operating conditions, placing the disk bluff-body 10 mm above the annular channel could better stabilize the flame. High speed Particle Image Velocimetry (PIV) was also used to get deeper insight into the characteristics of the flow fields and flame stabilization. The size and strength of the recirculation zone downstream of the bluff-body altered with the changing of bluff-body’s position and other operating conditions. The recirculation zone, in the burner with the bluff-body placed 10 mm above the air channel exit, was found larger and stronger than that in the other burner geometry. In the reacting case, a recirculation bubble was formed besides the bluff-body’s outer wall which enhanced the flame stabilization. It is also found that the combustion changed the flow fields by enlarging the recirculation bubbles downstream of the bluff-body.

Amorphous-to-nanocrystalline transition in silicon thin films by hydrogen diluted silane using PE-CVD method

2020 ◽  
Vol 13 ◽  
Author(s):  
Ashok Jadhavar ◽  
Vidya Doiphode ◽  
Ajinkya Bhorde ◽  
Yogesh Hase ◽  
Pratibha Shinde ◽  
...  
Keyword(s):  
Flow Rate ◽  
Volume Fraction ◽  
Defect Density ◽  
Hydrogen Flow Rate ◽  
Spectroscopy Analysis ◽  
Deposition Parameter ◽  
Hydrogen Flow ◽  
Cvd Method ◽  
Silicon Thin Films ◽  
Increasing Trend

: Herein, we report effect of variation of hydrogen flow rate on properties of Si:H films synthesized using PE-CVD method. Raman spectroscopy analysis show increase in crystalline volume fraction and crystallite size implying that hydrogen flow in PECVD promote the growth of crystallinity in nc-Si:H films with an expense of reduction in deposition rate. FTIR spectroscopy analysis indicates that hydrogen content in the film increases with increase in hydrogen flow rate and hydrogen is predominantly incorporated in Si-H2 and (Si-H2)n bonding configuration. The optical band gap determined using E04 method and Tauc method (ETauc) show increasing trend with increase in hydrogen flow rate and E04 is found higher than ETauc over the entire range of hydrogen flow rate studied. We also found that the defect density and Urbach energy also increases with increase in hydrogen flow rate. Photosensitivity (Photo /Dark) decreases from  103 to  1 when hydrogen flow rate increased from 30 sccm to 100 sccm and can attributed to amorphous-to-nanocrystallization transition in Si:H films. The results obtained from the present study demonstrated that hydrogen flow rate is an important deposition parameter in PE-CVD to synthesize nc-Si:H films.

scholarly journals Proposal of a stage-by-stage design method and its application on a multi-stage multiphase pump based on numerical simulations

2021 ◽  
Vol 13 (1) ◽  
pp. 168781402098731
Author(s):  
Yi Shi ◽  
Hongwu Zhu
Keyword(s):  
Volume Fraction ◽  
Design Method ◽  
Oil Field ◽  
Stage Design ◽  
Multiphase Pump ◽  
Flow Parameters ◽  
Multi Stage ◽  
Comparison Results ◽  
Third Stage ◽  
Gas Volume

Rotodynamic multiphase pumps are usually equipped with many compression units to provide sufficient boosting pressure for the transportation of production fluid in gas oil field. It is a challenge to maintain pump performance while flow parameters in each stage vary due to the compressibility of gas-liquid phase. In this article, a stage-by-stage design method is proposed to improve the boosting capability of a multiphase pump. Variations of flow parameters in each stage are investigated based on computational fluid dynamics (CFD) numerical simulation. Available methods to determinate main impeller geometry parameters of impeller are discussed. The stage-by-stage design method is applied on a five-stage multiphase pump when the inlet gas volume fraction (GVF) are 30% and 50% separately. The second stage is modified base on its corresponding inlet flow parameters when inlet GVF is 30% while the second and third stage are modified when inlet GVF is 50%. Flow parameters, pressure distribution and velocity distribution are compared between the original pump and modified pump. Differential pressure of the modified pump increases by 53.72 kPa and 58.57 kPa respectively when inlet GVFs are 30% and 50%. The feasibility of the stage-by-stage design method is verified through the comparison results.

scholarly journals Effect of the Gas Volume Fraction on the Pressure Load of the Multiphase Pump Blade

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 650
Author(s):  
Guangtai Shi ◽  
Dandan Yan ◽  
Xiaobing Liu ◽  
Yexiang Xiao ◽  
Zekui Shu
Keyword(s):  
Flow Rate ◽  
Static Pressure ◽  
Volume Fraction ◽  
Pump Impeller ◽  
Impeller Blade ◽  
Multiphase Pump ◽  
Pressure Load ◽  
Gas Volume Fraction ◽  
Power Capability ◽  
Gas Volume

The gas volume fraction (GVF) often changes from time to time in a multiphase pump, causing the power capability of the pump to be increasingly affected. In the purpose of revealing the pressure load characteristics of the multiphase pump impeller blade with the gas-liquid two-phase case, firstly, a numerical simulation which uses the SST k-ω turbulence model is verified with an experiment. Then, the computational fluid dynamics (CFD) software is employed to investigate the variation characteristics of static pressure and pressure load of the multiphase pump impeller blade under the diverse inlet gas volume fractions (IGVFs) and flow rates. The results show that the effect of IGVF on the head and hydraulic efficiency at a small flow rate is obviously less than that at design and large flow rates. The static pressure on the blade pressure side (PS) is scarcely affected by the IGVF. However, the IGVF has an evident effect on the static pressure on the impeller blade suction side (SS). Moreover, the pump power capability is descended by degrees as the IGVF increases, and it is also descended with the increase of the flow rate at the impeller inlet. Simultaneously, under the same IGVF, with the increase of the flow rate, the peak value of the pressure load begins to gradually move toward the outlet and its value from hub to shroud is increased. The research results have important theoretical significance for improving the power capability of the multiphase pump impeller.

scholarly journals Energy Loss in Steep Open Channels with Step-Pools

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 72
Author(s):  
Suresh Kumar Thappeta ◽  
S. Murty Bhallamudi ◽  
Venu Chandra ◽  
Peter Fiener ◽  
Abul Basar M. Baki
Keyword(s):  
Energy Loss ◽  
Flow Rate ◽  
Recirculation Zone ◽  
Three Dimensional ◽  
Nonlinear Function ◽  
Open Channels ◽  
Geometrical Parameters ◽  
Transition Flow ◽  
Cumulative Energy ◽  
Zone Velocity

Three-dimensional numerical simulations were performed for different flow rates and various geometrical parameters of step-pools in steep open channels to gain insight into the occurrence of energy loss and its dependence on the flow structure. For a given channel with step-pools, energy loss varied only marginally with increasing flow rate in the nappe and transition flow regimes, while it increased in the skimming regime. Energy loss is positively correlated with the size of the recirculation zone, velocity in the recirculation zone and the vorticity. For the same flow rate, energy loss increased by 31.6% when the horizontal face inclination increased from 2° to 10°, while it decreased by 58.6% when the vertical face inclination increased from 40° to 70°. In a channel with several step-pools, cumulative energy loss is linearly related to the number of step-pools, for nappe and transition flows. However, it is a nonlinear function for skimming flows.

Numerical study of the flow over the modified simple frigate shape

2020 ◽  
pp. 095441002097775
Author(s):  
Tong Li ◽  
Yibin Wang ◽  
Ning Zhao
Keyword(s):  
Bluff Body ◽  
Recirculation Zone ◽  
Numerical Study ◽  
Reference Value ◽  
Flow Fields ◽  
Navier Stokes ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation ◽  
Simulation Results

The simple frigate shape (SFS) as defined by The Technical Co-operative Program (TTCP), is a simplified model of the frigate, which helps to investigate the basic flow fields of a frigate. In this paper, the flow fields of the different modified SFS models, consisting of a bluff body superstructure and the deck, were numerically studied. A parametric study was conducted by varying both the superstructure length L and width B to investigate the recirculation zone behind the hangar. The size and the position of the recirculation zones were compared between different models. The numerical simulation results show that the size and the location of the recirculation zone are significantly affected by the superstructure length and width. The results obtained by Reynolds-averaged Navier-Stokes method were also compared well with both the time averaged Improved Delayed Detached-Eddy Simulation results and the experimental data. In addition, by varying the model size and inflow velocity, various flow fields were numerically studied, which indicated that the changing of Reynolds number has tiny effect on the variation of the dimensionless size of the recirculation zone. The results in this study have certain reference value for the design of the frigate superstructure.

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