scholarly journals INVESTIGATION OF THE INFLUENCE TWO-PHASE FLOWS PARAMETERS ON THE EROSION WEAR OF THE GAS PIPELINES BENDS

2020 ◽  
Vol 1 (154) ◽  
pp. 240-248
Author(s):  
Ya. Doroshenko
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Particle Diameter ◽  
Continuous Phase ◽  
Gas Pipeline ◽  
Cfd Modeling ◽  
Erosion Wear ◽  
Two Phase ◽  
Software Complex ◽  
Dispersed Particles

CFD modeling (Computational Fluid Dynamics) Lagrangian approach (model DPM (Discrete Phase Model)) in ANSYS Fluent R19.2 Academic software complex investigates the influence of twophase gas flow velocity, size and flow rate of dispersed particles on the location and magnitude of gas pipeline bends erosion wear. The motion of the continuous phase was modeled by the solution of the Navier-Stokes equation and the continuity of the closed two-parameter k-ε turbulence model with the corresponding initial and boundary conditions. The motion trajectories of the dispersed particles were determined by integrating the force equations acting on each particle. The erosion wear of gas pipeline bends was modeled using the Finney equation. The studies were performed for gas flow velocities at the inlet of the bend from 4 m/s to 19 m/s, the diameters of the dispersed particles 0.005 mm, 0.01 mm, 0.05 mm, 0.1 mm, 0.5 mm and 1.0 mm and the flow rate of the dispersed particles from 0.0002 kg/s to 0.0022 kg/s. Natural gas was selected as the continuous phase, and sand was dispersed. The geometry of each of the simulated taps and the pressure at the outlet of the bend were assumed to be the same. The simulation results were visualized in the postprocessor software complex by constructing erosion rate velocity fields on gas pipeline bends. From the visualized results it is determined that the largest influence on the location of the erosion wear of the pipeline bends has the diameter of the dispersed particles and the least concentration. The influence of the two-phase gas flow parameters on the location of the field of their maximum erosion wear is determined. The graphical dependences of the maximum velocity of erosion wear of gas pipeline bends on each of the studied parameters of the two-phase gas stream are constructed. It has been determined that the diameter of the dispersed particles and the velocity of the gas stream have the greatest influence on the erosion wear of the erosion of the bends. Keywords: bend, dispersed particle diameter, dispersed particle rate, dispersed phase, erosion wear, Finney equation, gas flow rate, Lagrange approach.

METHODOLOGICAL ASPECT OF ASSESSING RELIABILITY OF MEDIUM PRESSURE GAS PIPELINES

2021 ◽  
pp. 97-107
Author(s):  
A.I. Pashentsev ◽  
A.A. Garmider
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Methodological Approach ◽  
Gas Pipeline ◽  
Methodological Aspect ◽  
Gas Pipelines ◽  
Gas Flow Rate ◽  
Medium Pressure ◽  
Reliability Calculation

The author’s vision of the methodological aspect of assessing the reliability of medium pressure gas pipelines is presented. Analysis of existing methods for assessing the reliability of gas pipelines with the identification of positive and negative features was carried out, a methodological approach to assessing the reliability of medium pressure gas pipelines by gas flow rate and pressure was developed and tested, and a scale for identifying the results of reliability calculation was developed. The test conducted on the example of a really working gas pipeline with a test for reliability showed its promise.

scholarly journals Prediction Models of Droplet Characteristics Based on the Locally Convergent Configurations in PMMA Microchips

2021 ◽  
Vol 2097 (1) ◽  
pp. 012027
Author(s):  
Zhongxin Liu ◽  
Zhiliang Wang ◽  
Chao Wang ◽  
Jinsong Zhang
Keyword(s):  
Flow Rate ◽  
Relative Position ◽  
Prediction Models ◽  
Continuous Phase ◽  
Lubricating Oil ◽  
Flow Rate Ratio ◽  
Phase Flow ◽  
Exponential Relationship ◽  
Two Phase ◽  
Relationship Of

Abstract This paper novel designed the local convergence configuration in the coaxial channels to study the two-phase flow (lubricating oil (continuous phase, flow rate Q c)/deionized water (dispersed phase, flow rate Q d)). Two geometric control variables, the relative position (x) and tapering characteristics (α), had the different effects on the droplet formation. The increase of relative position x caused the higher frequency and finer droplets, and the increase of convergence angle α, took the opposite effects. The results indicated that the equivalent dimensionless droplet length Ld/Wout and the flow rate ratio Qd/Qc had an exponential relationship of about 1/2. Similarly, it was found that the dispersed droplets generating frequency and the two-phase capillary number, CaTP = uTPμc/σ, had an exponential relationship. The advantage of the convergent configurations in micro-channel was the size and efficiency of droplet generation was very favorable to be controlled by α and x.

Numerical Simulation and Analysis of Effect of Injection Volume on Biomass Particle Cyclone Venturi Dryer

2021 ◽  
Author(s):  
Guohai Jia ◽  
Guoshuai Tian ◽  
Zicheng Gao ◽  
Dan Huang ◽  
Wei Li ◽  
...  
Keyword(s):  
High Speed ◽  
Optimization Design ◽  
Gas Flow ◽  
Continuous Phase ◽  
Temperature Fields ◽  
Maximum Pressure ◽  
Two Phase ◽  
Velocity Change ◽  
Injection Volume ◽  
Wood Debris

Abstract Cyclone venturi dryer is suitable for drying materials with large particle size and wide distribution. The working process of cyclone venturi dryer is a very complicated three-dimensional and turbulent motion, so it is difficult to be studied theoretically and experimentally. In order to study the internal flow characteristics of the biomass particle cyclone venturi dryer, the computational fluid dynamics (CFD) software was used to simulate the gas-solid two-phase flow field inside the cyclone venturi dryer. The continuous phase adopts the Realizable k-ε turbulence model and the particle phase is discrete. The effects of different injection volume on the pressure, velocity, and temperature fields inside a cyclone venturi dryer were analyzed. The results showed that the maximum pressure drop and velocity change inside the dryer were at the venturi pipe. The wet material of the cyclone venturi dryer was inhaled into the venturi contraction tube by the negative pressure formed after the highspeed airflow was ejected, thus the mixture was completed in the venturi throat. The wood debris material was mixed with the high-speed hot gas flow in the venturi throat and then sprayed into the diffusion pipe. In the diffusion pipe of venturi, the heat and mass transfer process of wet wood debris and heat flow in venturi diffusion tube was completed. It is in good agreement with the simulation results. This study can provide a reference for the optimization design of the related cyclone venturi dryer structure.

Experimental, Numerical, and Statistical Investigation of Two Phase Flow in a Cylindrical Perforation Tunnel

2021 ◽  
Author(s):  
Ekhwaiter Abobaker ◽  
Abadelhalim Elsanoose ◽  
Mohammad Azizur Rahman ◽  
Faisal Khan ◽  
Amer Aborig ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Statistical Analysis ◽  
Flow Rate ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Gas Flow Rate ◽  
Two Phase ◽  
Flow Through

Abstract Perforation is the final stage in well completion that helps to connect reservoir formations to wellbores during hydrocarbon production. The drilling perforation technique maximizes the reservoir productivity index by minimizing damage. This can be best accomplished by attaining a better understanding of fluid flows that occur in the near-wellbore region during oil and gas operations. The present work aims to enhance oil recovery by modelling a two-phase flow through the near-wellbore region, thereby expanding industry knowledge about well performance. An experimental procedure was conducted to investigate the behavior of two-phase flow through a cylindrical perforation tunnel. Statistical analysis was coupled with numerical simulation to expand the investigation of fluid flow in the near-wellbore region that cannot be obtained experimentally. The statistical analysis investigated the effect of several parameters, including the liquid and gas flow rate, liquid viscosity, permeability, and porosity, on the injection build-up pressure and the time needed to reach a steady-state flow condition. Design-Expert® Design of Experiments (DoE) software was used to determine the numerical simulation runs using the ANOVA analysis with a Box-Behnken Design (BBD) model and ANSYS-FLUENT was used to analyses the numerical simulation of the porous media tunnel by applying the volume of fluid method (VOF). The experimental data were validated to the numerical results, and the comparison of results was in good agreement. The numerical and statistical analysis demonstrated each investigated parameter’s effect. The permeability, flow rate, and viscosity of the liquid significantly affect the injection pressure build-up profile, and porosity and gas flow rate substantially affect the time required to attain steady-state conditions. In addition, two correlations obtained from the statistical analysis can be used to predict the injection build-up pressure and the required time to reach steady state for different scenarios. This work will contribute to the clarification and understanding of the behavior of multiphase flow in the near-wellbore region.

Numerical Simulation of Thermal Cycle of In-Service Welding on X70 Steel Gas Pipeline

2009 ◽  
Vol 79-82 ◽  
pp. 1169-1172 ◽  
Author(s):  
Yu Hua Chen ◽  
Yong Wang ◽  
Zheng Fang Wang
Keyword(s):  
Flow Rate ◽  
Thermal Cycle ◽  
Gas Flow ◽  
Gas Pressure ◽  
Gas Pipeline ◽  
Peak Temperature ◽  
Coarse Grain ◽  
Air Cooling ◽  
Gas Flow Rate ◽  
Oil Gas

In-service welding is a kind of important method to ensure the integrality of oil gas pipeline and the thermal cycle of which is significant for repairing. Used SYSWELD to establish model and simulate thermal cycle of in-service welding on X70 steel gas pipeline, compared thermal cycles of in-service welding and air-cooling welding, studied the influence of gas pressure and flow rate on thermal cycle. The result shows that peak temperature of the coarse grain in heat affected zone (CGHAZ) of in-service welding is similar to air cooling welding, but the cooling time of t8/5, t8/3 and t8/1 decreases at certain degree. Peak temperature of CGHAZ of in-service welding doesn’t vary match with gas pressure and flow rate either. t8/5, t8/3 and t8/1 decrease when gas pressure increases. t8/5 varies with the gas pressure linearly. When the pressure is less than 4MPa, t8/3 and t8/1 decrease rapidly while gas pressure increases. When the pressure is more than 4MPa, t8/3 and t8/1 decrease slowly while gas pressure increases. t8/5, t8/3 and t8/1 decrease when the flow rate increases. When gas flow rate is less than 10m/s, t8/5, t8/3 and t8/1 decrease rapidly while flow rate increases. When gas flow rate is more than 10m/s, t8/5, t8/3 and t8/1 decrease slowly while flow rate increases.

Wet Gas Flow Metering Based on Differential Pressure and BSS Techniques

2011 ◽  
Vol 383-390 ◽  
pp. 4922-4927
Author(s):  
Peng Xia Xu ◽  
Yan Feng Geng
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Differential Pressure ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Metering ◽  
Wet Gas

Wet gas flow is a typical two-phase flow with low liquid fractions. As differential pressure signal contains rich information of flow parameters in two-phase flow metering, a new method is proposed for wet gas flow metering based on differential pressure (DP) and blind source separation (BSS) techniques. DP signals are from a couple of slotted orifices and the BSS method is based on time-frequency analysis. A good relationship between the liquid flow rate and the characteristic quantity of the separated signal is established, and a differential pressure correlation for slotted orifice is applied to calculate the gas flow rate. The calculation results are good with 90% relative errors less than ±10%. The results also show that BSS is an effective method to extract liquid flow rate from DP signals of wet gas flow, and to analysis different interactions among the total DP readings.

Visualization Study on Two-Phase Flow Behaviors in the Gas-Liquid-Solid Microreactor for Hydrogenation of Nitrobenzene

2016 ◽  
Author(s):  
Hao Feng ◽  
Xun Zhu ◽  
Rong Chen ◽  
Qiang Liao
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Flow Direction ◽  
Flow Characteristics ◽  
Phase Flow ◽  
Microchannel Reactor ◽  
Two Phase ◽  
Modified Surface

In this study, visualization study on the gas-liquid two phase flow characteristics in a gas-liquid-solid microchannel reactor was carried out. Palladium nanocatalyst was coated onto the polydopamine functionalized surface of the microchannel through eletroless deposition. The materials characterization results indicated that palladium nanocatalyst were well dispersed on the modified surface. The effects of both the gas and liquid flow rates as well as inlet nitrobenzene concentration on the two-phase flow characteristics were studied. The experimental results revealed that owing to the chemical reaction inside the microreactor, the gas slug length gradually decreased along the flow direction. For a given inlet nitrobenzene concentration, increasing the liquid flow rate or decreasing the gas flow rate would make the variation of the gas slug length more obvious. High inlet nitrobenzene concentration would intensify both the nitrobenzene transfer efficiency and gas reactants consumption, and thereby the flow pattern in the microchannel was transferred from Taylor flow into bubble flow. Besides, the effect of both flow rate and original nitrobenzene concentration on the variation of nitrobenzene conversion and the desired product aniline yield were also discussed.

scholarly journals Experimental Study on the Effect of Locally Convergent Configurations on the Flow Pattern in PMMA Microchips

2021 ◽  
Vol 2097 (1) ◽  
pp. 012006
Author(s):  
Jinsong Zhang ◽  
Zhongxin Liu ◽  
Chao Wang ◽  
Zhiliang Wang
Keyword(s):  
Flow Rate ◽  
Rectangular Cross Section ◽  
Continuous Phase ◽  
Lubricating Oil ◽  
Phase Flow ◽  
Two Phase ◽  
Convergence Angle ◽  
Syringe Needle ◽  
Micro Flow ◽  
Two Parameters

Abstract The geometries of micro-channel play a key role in forming of digital droplets, and can be real-time or effective controlling methodologies. Local convergence regions are designed in the rectangular cross-section channels on PMMA microchips, in which two-phase coaxial jets are introduced by inserting a syringe needle. The two-phase flow (lubricating oil (continuous phase, flow rate Q c)/deionized water (dispersed phase, flow rate Q d)) is considered. Two geometric control variables, the relative position (needle displacement x) and tapering characteristics (convergence angle α), are naturally adopted to discribe such geometry configurations. The micro-flow under the change of these two parameters is mainly studied in this paper. Four kinds of characteristic flow patterns, namely, sausages, slug, dripping and jetting, are found in the experiment, and their occurring parameters and developing dynamic characteristics are discussed. The experiment shows that the increase of inner needle displacement x can produce higher frequency and finer droplets, which is in consistent with our previous results obtained in round tube experiments and simulations. While increasing the convergence angle α, contrarily, takes opposite effects.

A Review of Wet Gas Flow Rate Measurements by Means of Single-Phase Meters

2018 ◽  
Author(s):  
Enrico Munari ◽  
Michele Pinelli
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Single Phase ◽  
Rate Measurement ◽  
Gas Flow Rate ◽  
Flow Rate Measurement ◽  
Two Phase ◽  
Beneficial Effects ◽  
Wet Gas ◽  
Depth Analysis

Nowadays, wet gas flow rate measurement is still a challenge for experimental investigators and it is becoming an even more important issue to overcome in the turbomachinery sector as well, due to the increasing trend of wet compression applications in industry. The requirement to determine gas turbine performance when processing a wet gas leads to the need to understand certain phenomena, such as type of liquid flow re-distribution, and errors introduced when the mass flow rate measurement of a two-phase gas is attempted. Unfortunately, this measurement is often affected by the presence of liquid. Literature does not offer a unique definition of the term wet gas, although it is recognized that a wet gas can generally be defined as a two-phase gas in which the liquid percentage is lower than the gas one. This paper aims to collect and describe the main works present in literature in order to clarify i) the most used parameters that describe the types of wet gas, and ii) the types of errors and flow patterns which occur in different types of applications, in terms of pressure, percentage of liquid, Reynolds number, etc. Therefore, this literature review offers a comprehensive description of the possible effects of liquid presence in a wet gas and, and an in-depth analysis of the limitations and beneficial effects of current single-phase flow rate sensors in order to identify the best solutions, and empirical corrections available in literature to overcome this challenge.

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