scholarly journals Effects of Diameters on Countercurrent Flow Limitation at a Square Top End in Vertical Pipes

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Michio Murase ◽  
Koji Nishida ◽  
Toshihide Torige ◽  
Toshiya Takaki ◽  
Raito Goda ◽  
...  
Keyword(s):  
Water Level ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Strong Relationship ◽  
Countercurrent Flow ◽  
Flow Limitation ◽  
Vertical Pipe ◽  
Surge Line ◽  
Inclined Pipe

The falling liquid flow rate under flooding conditions is limited at a square top end of a vertical pipe in the pressurizer surge line with the diameter of about 300 mm that consists of a vertical pipe, a vertical elbow, and a slightly inclined pipe with elbows. In this study, therefore, we evaluated effects of diameters on countercurrent flow limitation (CCFL) at the square top end in vertical pipes by using existing air-water data in the diameter range of D = 19-250 mm. As a result, we found that there was a strong relationship between the constant CK and the slope m in the Wallis-type correlation where the Kutateladze parameters were used for the dimensionless gas and liquid velocities. The constant CK and the slope m increased when the water level is increased in the upper tank h. CCFL at the square top end of the vertical pipes could be expressed by the Kutateladze parameters with CK = 1.53±0.11 and m = 0.97 for D ≥ 30 mm. The CK values were smaller for D = 19-25 mm than those for D ≥ 30 mm.

Prediction Method of Countercurrent Flow Limitation in a Pressurizer Surge Line and Its Evaluation for a 1/10-Scale Model

2016 ◽  
Vol 2 (3) ◽  
Author(s):  
Michio Murase ◽  
Yoichi Utanohara ◽  
Takayoshi Kusunoki ◽  
Dirk Lucas ◽  
Akio Tomiyama
Keyword(s):  
Numerical Simulations ◽  
Prediction Method ◽  
3D Simulation ◽  
Scale Model ◽  
Countercurrent Flow ◽  
Flow Limitation ◽  
Vertical Pipe ◽  
Pressurized Water ◽  
Surge Line ◽  
Inclined Pipe

The method for predicting countercurrent flow limitation (CCFL) and its uncertainty in an actual pressurizer surge line of a pressurized water reactor (PWR) using 1/10-scale air–water experimental data, one-dimensional (1D) computations, and three-dimensional (3D) numerical simulations was proposed. As one step of the prediction method, 3D numerical simulations were carried out for countercurrent air–water flows in a 1/10-scale model of the pressurizer surge line to evaluate capability of the 3D simulation method and decide uncertainty of CCFL characteristics evaluated for the 1/10-scale model. The model consisted of a vertical pipe, a vertical elbow, and a slightly inclined pipe with elbows. In the actual 1/10-scale experiment, air supplied into the lower tank flowed upward to the upper tank and water supplied into the upper tank gravitationally flowed downward to the lower tank through the pressurizer surge line. In the 3D simulation, however, water was supplied from the wall surface of the vertical pipe to avoid effects of flooding at the upper end (the 3D simulation largely underestimated falling water flow rates at the upper end). Then, the flow pattern in the slightly inclined pipe was successfully reproduced, and the simulated CCFL values for the inclination angle of θ=0.6  deg (slope of 1/100) agreed well with the experimental CCFL data. The uncertainty among air–water experiments, 1D computations, and 3D simulations for the 1/10-scale model was dC=±0.015 for the CCFL constant of C=0.50. The effects of θ (θ=0,1.0 deg) on CCFL characteristics were simulated and discussed.

scholarly journals Gas–Liquid Two-Phase Upward Flow through a Vertical Pipe: Influence of Pressure Drop on the Measurement of Fluid Flow Rate

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2937 ◽  
Author(s):  
Tarek Ganat ◽  
Meftah Hrairi
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Friction Factor ◽  
Relative Error ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Oil Wells ◽  
Fluid Flow Rate ◽  
Vertical Pipe

The accurate estimation of pressure drop during multiphase fluid flow in vertical pipes has been widely recognized as a critical problem in oil wells completion design. The flow of fluids through the vertical tubing strings causes great losses of energy through friction, where the value of this loss depends on fluid flow viscosity and the size of the conduit. A number of friction factor correlations, which have acceptably accurate results in large diameter pipes, are significantly in error when applied to smaller diameter pipes. Normally, the pressure loss occurs due to friction between the fluid flow and the pipe walls. The estimation of the pressure gradients during the multiphase flow of fluids is very complex due to the variation of many fluid parameters along the vertical pipe. Other complications relate to the numerous flow regimes and the variabilities of the fluid interfaces involved. Accordingly, knowledge about pressure drops and friction factors is required to determine the fluid flow rate of the oil wells. This paper describes the influences of the pressure drop on the measurement of the fluid flow by estimating the friction factor using different empirical friction correlations. Field experimental work was performed at the well site to predict the fluid flow rate of 48 electrical submersible pump (ESP) oil wells, using the newly developed mathematical model. Using Darcy and Colebrook friction factor correlations, the results show high average relative errors, exceeding ±18.0%, in predicted liquid flow rate (oil and water). In gas rate, more than 77% of the data exceeded ±10.0% relative error to the predicted gas rate. For the Blasius correlation, the results showed the predicted liquid flow rate was in agreement with measured values, where the average relative error was less than ±18.0%, and for the gas rate, 68% of the data showed more than ±10% relative error.

Absorption of oxygen into solutions of polymers

1986 ◽  
Vol 51 (10) ◽  
pp. 2127-2134 ◽  
Author(s):  
František Potůček ◽  
Jiří Stejskal
Keyword(s):  
Mass Transfer ◽  
Aqueous Solutions ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Liquid Flow ◽  
Flow Curve ◽  
Liquid Flow Rate ◽  
Polymer Concentration ◽  
Newtonian Liquids

Absorption of oxygen into water and aqueous solutions of poly(acrylamides) was studied in an absorber with a wetted sphere. The effects of changes in the liquid flow rate and the polymer concentration on the liquid side mass transfer coefficient were examined. The results are expressed by correlations between dimensionless criteria modified for non-Newtonian liquids whose flow curve can be described by the Ostwald-de Waele model.

scholarly journals Effects of water salinity on the foam dynamics for EOR application

2021 ◽  
Author(s):  
Svetlana Rudyk ◽  
Sami Al-Khamisi ◽  
Yahya Al-Wahaibi
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Apparent Viscosity ◽  
Liquid Flow Rate ◽  
Salinity Range ◽  
Porous System ◽  
Foam Formation ◽  
Total Flow ◽  
Total Flow Rate ◽  
Foam Flow

AbstractFactors limiting foam injection for EOR application are exceptionally low rock permeability and exceedingly high salinity of the formation water. In this regard, foam formation using internal olefin sulfonate is investigated over a wide salinity range (1, 5, 8, 10, and 12% NaCl) through 10 mD limestone. The relationships between pressure drop (dP), apparent viscosity, liquid flow rate, total flow rate, salinity, foam texture, and length of foam drops at the outlet used as an indicator of viscosity are studied. Foaming is observed up to 12% NaCl, compared to a maximum of 8% NaCl in similar core-flooding experiments with 50 mD limestone and 255 mD sandstone. Thus, the salinity limit of foam formation has increased significantly due to the low permeability, which can be explained by the fact that the narrow porous system acts like a membrane with smaller holes. Compared to the increasing dP reported for highly permeable rocks, dP linearly decreases in almost the entire range of gas fraction (fg) at 1–10% NaCl. As fg increases, dP at higher total flow rate is higher at all salinities, but the magnitude of dP controls the dependence of apparent viscosity on total flow rate. Low dP is measured at 1% and 10% NaCl, and high dP is measured at 5, 8, and 12% NaCl. In the case of low dP, the apparent viscosity is higher at higher total flow rate with increasing gas fraction, but similar at two total flow rates with increasing liquid flow rate. In the case of high dP, the apparent viscosity is higher at lower total flow rate, both with an increase in the gas fraction and with an increase in the liquid flow rate. A linear correlation is found between dP or apparent viscosity and liquid flow rate, which defines it as a governing factor of foam flow and can be considered when modeling foam flow.

Numerical Simulation of Gas-Liquid Two-Phase Flows on Wetted Walls

2010 ◽  
Author(s):  
Yoshiyuki Iso ◽  
Xi Chen
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Liquid Flow ◽  
Film Flow ◽  
Liquid Flow Rate ◽  
Flow Transition ◽  
Wall Surface ◽  
Two Phase ◽  
Wall Flows ◽  
Rivulet Flow

Gas-liquid two-phase flows on the wall like liquid film flows, which are the so-called wetted wall flows, are observed in many industrial processes such as absorption, desorption, distillation and others. For the optimum design of packed columns widely used in those kind of processes, the accurate predictions of the details on the wetted wall flow behavior in packing elements are important, especially in order to enhance the mass transfer between the gas and liquid and to prevent flooding and channeling of the liquid flow. The present study focused on the effects of the change of liquid flow rate and the wall surface texture treatments on the characteristics of wetted wall flows which have the drastic flow transition between the film flow and rivulet flow. In this paper, the three-dimensional gas-liquid two-phase flow simulation by using the volume of fluid (VOF) model is applied into wetted wall flows. Firstly, as one of new interesting findings in this paper, present results showed that the hysteresis of the flow transition between the film flow and rivulet flow arose against the increasing or decreasing stages of the liquid flow rate. It was supposed that this transition phenomenon depends on the history of flow pattern as the change of curvature of interphase surface which leads to the surface tension. Additionally, the applicability and accuracy of the present numerical simulation were validated by using the existing experimental and theoretical studies with smooth wall surface. Secondary, referring to the texture geometry used in an industrial packing element, the present simulations showed that surface texture treatments added on the wall can improve the prevention of liquid channeling and can increase the wetted area.

New approach to maintaining liquid flow rate stability in national primary standard

2021 ◽  
pp. 101930
Author(s):  
N.I. Mikheev ◽  
V.M. Molochnikov ◽  
D.V. Kratirov ◽  
O.A. Dushina ◽  
A.A. Paereliy ◽  
...  
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Primary Standard ◽  
New Approach ◽  
National Primary Standard

The ukrainian state standard for the liquid flow rate unit

2007 ◽  
Vol 50 (6) ◽  
pp. 641-650
Author(s):  
V. B. Bol’shakov ◽  
N. I. Kosach
Keyword(s):  
Flow Rate ◽  
State Standard ◽  
Liquid Flow ◽  
Liquid Flow Rate

Simulation of Liquid-Gas Replacement in Commissioning Process for Large-Slope Crude Oil Pipeline

2012 ◽  
Author(s):  
Yuanyuan Chen ◽  
Jing Gong ◽  
Xiaoping Li ◽  
Nan Zhang ◽  
Shaojun He ◽  
...  
Keyword(s):  
Crude Oil ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Fluid Model ◽  
Engineering Application ◽  
Computational Procedure ◽  
Control Measures ◽  
Production Operation ◽  
Oil Pipeline

Pipeline commissioning, which is a key link from engineering construction to production operation, is aim to fill an empty pipe by injecting water or oil to push air out of it. For a large-slope crude oil pipeline with great elevation differences, air is fairly easy to entrap at downward inclined parts. The entrapped air, which is also called air pocket, will cause considerable damage on pumps and pipes. The presence of it may also bring difficulties in tracking the location of the liquid head or the interface between oil and water. It is the accumulated air that needed to be exhausted in time during commissioning. This paper focuses on the simulation of liquid-gas replacement in commissioning process that only liquid flow rate exists while gas stays stagnant in the pipe and is demanded to be replaced by liquid. Few previous researches have been found yet in this area. Consequently, the flow in a V-section pipeline consisted of a downhill segment and a subsequent uphill one is used here for studying both the formation and exhaustion behaviors of the intake air. The existing two-fluid model and simplified non-pressure wave model for gas-liquid stratified flow are applied to performance the gas formation and accumulation. The exhausting process is deemed to be a period in which the elongated bubble (Taylor bubble) is fragmented into dispersed small bubbles. A mathematical model to account for gas entrainment into liquid slug is proposed, implemented and incorporated in a computational procedure. By taking into account the comprehensive effects of liquid flow rate, fluid properties, surface tension, and inclination angle, the characteristics of the air section such as the length, pressure and mass can be calculated accurately. The model was found to show satisfactory predictions when tested in a pipeline. The simulation studies can provide theoretical support and guidance for field engineering application, which are meanwhile capable of helping detect changes in parameters of gas section. Thus corresponding control measures can be adopted timely and appropriately in commissioning process.

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