scholarly journals Modeling and Simulation of Pigging for a Gas Pipeline Using a Bypass Pig

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Liang Zhang ◽  
Jiawei Zhou ◽  
Honggang He
Keyword(s):  
Sensitivity Analysis ◽  
Response Surface Methodology ◽  
Flow Rate ◽  
Gas Flow ◽  
Method Of Characteristics ◽  
Gas Pipeline ◽  
Parametric Sensitivity ◽  
Pipeline Inspection ◽  
Bypass Valve ◽  
Unsteady Gas Flow

The pipeline inspection gauge (PIG, lowercase pig is commonly used) with a bypass valve is widely used in pipeline inspection because it operates at a low speed without reducing the flow rate. Understanding the dynamics of a bypass pig in a gas pipeline would contribute to the design of the pig and the control of pig speed. This paper deals with the dynamic model for the process of a bypass pig travelling through a hilly gas pipeline. The method of characteristics (MOC) is used to solve the equations of unsteady gas flow. The backward flow of the gas in the bypass valve and pipe is shown by a simulation of pigging for a hilly gas pipeline. Parametric sensitivity analysis of pigging in the horizontal gas pipe using a bypass pig is then carried out. The results indicate that the speed of a bypass pig is most sensitive to the gas speed in the pipe followed by the bypass area and the friction of the pig. A formula, obtained from the results of the simulations using response surface methodology (RSM), is presented to predict the steady speed of a bypass pig in the horizontal gas pipeline.

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.

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.

Research Note: An Alternative Scheme to Solve the Equations for Unsteady Gas Flow

1976 ◽  
Vol 18 (3) ◽  
pp. 161-166
Author(s):  
J. F. T. MacLaren ◽  
A. B. Tramschek ◽  
O. F. Pastrana ◽  
A. Sanjines
Keyword(s):  
Mathematical Models ◽  
Gas Flow ◽  
Method Of Characteristics ◽  
Research Note ◽  
Alternative Scheme ◽  
Flow Equations ◽  
The Method Of Characteristics ◽  
Unsteady Gas Flow ◽  
Engine Systems

A scheme which combines the ‘leap-frog’ method and the method of characteristics was found to be an efficient way to solve the unsteady gas flow equations which form the basis of mathematical models of compressor or engine systems.

scholarly journals Optimization of Ammonia Stripping of Piggery Biogas Slurry by Response Surface Methodology

2019 ◽  
Vol 16 (20) ◽  
pp. 3819 ◽  
Author(s):  
Mengyuan Zou ◽  
Hongmin Dong ◽  
Zhiping Zhu ◽  
Yuanhang Zhan
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Flow Rate ◽  
Gas Flow ◽  
Ph Value ◽  
Removal Rate ◽  
Ammonia Nitrogen ◽  
Biogas Slurry ◽  
Gas Flow Rate ◽  
Ammonia Stripping

Ammonia stripping is a pretreatment method for piggery biogas slurry, and the effectiveness of the method is affected by many factors. Based on the results of single-factor experiments, response surface methodology is adopted to establish a quadratic polynomial mathematical model relating stripping time, pH value and gas flow rate to the average removal rate of ammonia nitrogen to explore the interactions among various influencing factors, obtain optimized combined parameters for ammonia stripping, and carry out experimental verification of the parameters. The results show that when hollow polyhedral packing is adopted under operating conditions including a stripping time of 90 min, pH value of 11, gas flow rate of 28 m3/h, gas–liquid ratio of 2000 and temperature of 30 °C, the average removal rate of ammonia nitrogen in biogas slurry can reach approximately 73%. The experimental value is only 4.2% different from the predicted value, which indicates that analysis on the interaction among factors influencing ammonia stripping of biogas slurry and parameter optimization of the regression model are accurate and effective.

Application of Response Surface Methodology to Investigate CO2 Absorption Column Temperature Rise

2014 ◽  
Vol 917 ◽  
pp. 257-266 ◽  
Author(s):  
Lian See Tan ◽  
Mohd Shariff Azmi ◽  
Lau Kok Keong ◽  
Mohammad Azmi Bustam
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Flow Rate ◽  
Temperature Rise ◽  
Gas Flow ◽  
Liquid Temperature ◽  
Inlet Concentration ◽  
Gas Flow Rate ◽  
Column Temperature ◽  
Column Pressure

This study aims to investigate the impact of process parameters to the column temperature rise during the absorption process using response surface methodology (RSM). The parameters studied were liquid temperature, column pressure, CO2 inlet concentration and gas flow rate. While all the factors studied had significant impact to the quadratic model for the temperature rise, the magnitude of temperature rise was more obvious with the variation of column pressure and CO2 inlet concentration. The column temperature rise was found to be high when the liquid temperature, column pressure and CO2 inlet concentration were high. Similar behavior of high column temperature rise was also observed when the gas flow rate was low.

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.

scholarly journals Method of characteristics for the problems of stages of the serviceability check of elementary section of a gas pipeline for operation

2021 ◽  
Vol 2131 (3) ◽  
pp. 032117
Author(s):  
I K Khujaev ◽  
Kh Aminov ◽  
S Akhmadjonov ◽  
A Ismailov
Keyword(s):  
Analytical Solution ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Method Of Characteristics ◽  
Gas Injection ◽  
Gas Pipeline ◽  
Dynamic State ◽  
Gas Dynamic ◽  
Elementary Section

Abstract The article is devoted to modeling the gas-dynamic state of an elementary section of a gas pipeline during gas injection and its outflow through the choke in the final section of the pipe and to solving these problems using the method of characteristics. The subject of the study is the gas-dynamic state of an elementary horizontal section of a gas pipeline in the process of checking its serviceability for operation. The processes of gas injection into the section and gas outflow from it, considered in the article, were modeled using the N.E. Zhukovsky formula on gas outflow into unbounded space in a framework of the short pipeline approach. The original equations are linearized by introducing the mass flow rate of gas and waves traveling in two directions. When solving the problem, the method of characteristics was applied; numerical results were obtained and analyzed using an analytical solution to the problem. The research methods are based on the laws of conservation of momentum and gas mass, the d’Alembert method for solving a system of hyperbolic equations and the methods of conducting a computational experiment. An analytical solution to the problem with a rupture caused by an instantaneous change in the gas pressure at the end of the section is obtained. It is shown that the process proceeds with the formation of compression and rarefaction waves, and their multiple reflections at the ends of the section. The gas in the section tends to a state of rest with time, and the changes in the mass flow rate and gas pressure are of exponential nature.

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