The Effects of Heat Input and Gas Flow Rate on Weld Integrity for Sleeve Repair Welding of In-Service Gas Pipelines

2002 ◽  
Author(s):  
Woo-Sik Kim ◽  
Young-Pyo Kim ◽  
Kyu Hwan Oh
Keyword(s):  
Internal Pressure ◽  
Flow Rate ◽  
Heat Input ◽  
Gas Flow ◽  
Numerical Study ◽  
Maximum Temperature ◽  
Gas Flow Rate ◽  
Element Analysis ◽  
Fillet Welding ◽  
Repair Welding

The experimental and numerical study has been conducted on the sleeve-repair welding of API 5L X65 pipeline. In order to simulate the in-service condition, the internal pressure of 45kgf/cm2 was applied using a nitrogen gas. SMAW and GTAW were applied to weld the sleeve. The macrostructure and hardness of repair welds have been examined. The finite element analysis of the multi-pass sleeve-fillet welding has been conducted to validate the experiment and investigate the effects of in-service welding conditions. The effect of gas flow rate on the hydrogen cracking was investigated. The effect of internal pressure on residual stresses and plastic strain was investigated. The allowable heat input was predicted considering the maximum temperature of inner surface of pipe and cooling rate at CGHAZ from the simulation of 1-pass sleeve-fillet welding.

Investigation of Multiphase Flow in Porous Media Around Perforation Tunnel Near Wellbore Region, Experimental and Numerical Study

2021 ◽  
Author(s):  
Abadelhalim Elsanoose ◽  
Ekhwaiter Abobaker ◽  
Faisal Khan ◽  
Aziz Rahman ◽  
Amer Aborig
Keyword(s):  
Porous Media ◽  
Multiphase Flow ◽  
Flow Rate ◽  
Gas Flow ◽  
Numerical Study ◽  
Flow In Porous Media ◽  
Dominant Factor ◽  
Porous System ◽  
Gas Flow Rate ◽  
Pressure Buildup

Abstract Understanding the behavior of the multiphase flow in the porous media near the wellbore region is essential for increasing wells’ productivity and oil recovery. In this paper, an experimental and numerical study of multiphase flow in porous media near a perforation tunnel is presented. The effect of properties on the flow, such as porosity and permeability, are crucial for increasing oil and gas production. Two-phase flow through a cylindrical porous media with a perforation tunnel samples experimentally and numerically tested. Five sandstone samples were created at Memorial university labs, the sample dimensions are 30.48 cm high, 15.54 cm diameter, and a perforation tunnel has a 25.54 cm depth and 2.54cm diameter. The air and water injected into the sample radially at different flow rates, the water flow rate ranged from 1 to 3 LPM, and the air 3 to 9 LPM. The simulation carried out using ANSYS-Fluent 18.1 commercial software simulates the Volume Of Fluid method VOF coupled with the different turbulent models used to simulate the flow. The results showed that the porous media’s pressure buildup is greatly affected by the gas flow rate and its permeability. The wellbore pressure and porosity have more negligible effect on the pressure buildup profile in the porous media. The dominant factor for the breakthrough of a fluid in a core sample is the gas flow rate. Incorporating the gas flow in a porous system will reduce hydrostatic pressure loss, and less time is required to activate the breakthrough time.

Effect of Processing Parameters on Plasma Jet and In-flight Particles Characters in Supersonic Plasma Spraying

2016 ◽  
Vol 35 (8) ◽  
pp. 775-786 ◽  
Author(s):  
Pei Wei ◽  
Zhengying Wei ◽  
Guangxi Zhao ◽  
Y. Bai ◽  
Chao Tan
Keyword(s):  
Plasma Spraying ◽  
Flow Rate ◽  
Gas Flow ◽  
Plasma Jet ◽  
Processing Parameters ◽  
Current Intensity ◽  
Maximum Temperature ◽  
Gas Flow Rate ◽  
Average Maximum ◽  
Supersonic Plasma

AbstractIn supersonic plasma spraying system (SAPS), heat transfer from arc plasma is characterized by several distinct features, such as transport of dissociation and ionization energy and of electrical charges in addition to mass transport. The thermodynamic and transport properties of plasma jet were influenced by several main parameters such as primary gas flow rate, the H2 vol.% and current intensity A. This paper first analyzes the effect of these parameters on the temperature and velocity of plasma jet theoretically. Further, the loading particles were melted and accelerated by plasma jet. Effects of several main parameters such as carrier gas flow rate, the H2 vol.%, the current intensity, the voltage and the spraying distance on temperature and velocity of in-flight particle were studied experimentally. The average maximum temperature and velocity of in-flight particle at any given parameters were systematically quantified. Optimal SAPS process parameters were given in this paper. In general, increasing the particles impacting velocity and surface temperature can improve the maximum spreading factor and decrease the coating porosity.

Numerical Study of Transport and Reaction Phenomena in GaN Vapor Phase Epitaxy

2005 ◽  
Author(s):  
D. Cai ◽  
L. L. Zheng
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Vapor Phase ◽  
Flow Rate ◽  
Gas Flow ◽  
Numerical Study ◽  
Vapor Phase Epitaxy ◽  
Mixing Process ◽  
Gas Flow Rate ◽  
Geometric Conditions

A vapor phase epitaxy (VPE) system has been designed to grow high quality gallium nitride layers under the deposition temperature of 990°C and the pressure range of 200–800 Torr. For the better understanding of the deposition mechanism of GaN layers, a numerical model that is capable of describing multi-component fluid flow, gas/surface chemistry, conjugate heat transfer, thermal radiation, and species transport, has been developed to help in design and optimization of the epitaxy growth system. The vacuum area between heaters and reactor tube is simulated as a solid body with small thermal conductivity and totally transparent to radiative heat transfer. Simulation results were compared to the experimental data to examine the temperature distribution achieved inside the growth reactor. To optimize operating parameters, the reaction mechanism for GaN in the VPE system has been identified, and the comprehensive computational simulations have been performed to study the temperature distribution, species mixing process, ammonia decomposition process and GaN deposition rate distribution on the substrate. Parametric studies have been performed to investigate the effects of operational and geometric conditions, such as temperature, reacting/carrier gas flow rate and distance between the substrate and the nozzle, on species mixing process and GaN deposition uniformity. The relationship between gas flow rate and III/V ratio achieved on the substrate will be established.

FORMATION OF NANOLITER BUBBLES IN MICROFLUIDIC T-JUNCTIONS

NANO ◽  
2010 ◽  
Vol 05 (03) ◽  
pp. 175-184 ◽  
Author(s):  
JING FAN ◽  
YUXIANG ZHANG ◽  
LIQIU WANG
Keyword(s):  
Liquid Phase ◽  
Flow Rate ◽  
Formation Process ◽  
Relative Velocity ◽  
Gas Flow ◽  
Numerical Study ◽  
Bubble Formation ◽  
Pressure Variation ◽  
Width Ratio ◽  
Gas Flow Rate

A numerical study on nanoliter bubble formation process in microfluidic T-junctions is conducted. The simulated bubble sequence agrees well with experiments. The pressure and velocity distribution in liquid phase, and streamlines of relative velocity of liquid to bubbles are obtained. We also studied pressure variation at the junction and gas flow rate for the first several bubbles, and illustrated the special impact of channel width ratio on bubble formation process. Finally, we derived the critical nondimensional gas pressure above which bubbles can be generated.

Numerical Study on Bubble-Melt Two-Phase Flows in the Production Process of Aluminum Foams

2011 ◽  
Vol 704-705 ◽  
pp. 796-803
Author(s):  
Hong Liu ◽  
Mao Zhao Xie ◽  
Jun Rui Shi ◽  
Hong Sheng Liu
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Reference Frames ◽  
Numerical Study ◽  
Fluid Model ◽  
Bubble Diameter ◽  
Functional Materials ◽  
Gas Flow Rate ◽  
Aluminum Foams ◽  
Two Phase

Aluminum foams, as a representative of metallic foams, are a kind of very useful and promising functional materials. This paper reports progress in three-dimensional numerical simulations of gas bubble-metallic melt turbulent flows during the foaming process of aluminum foams, in which air is injected into molten aluminum composites and the melt is mechanical stirred by a pitched-blade impeller with an inclined shaft. The bubble-melt two phase flow in the tank is described with an Eulerian-Eulerian two fluid model, the impeller flow region is simulated based on the Multiple Reference Frames (MRF) method. Influences of gas flow rate, impeller rotation speed and initial bubble diameter on the characteristics of the liquid flow field and gas fraction distribution are examined. Computational results show that bubbles tend to accumulate behind the impeller blades and have an approximately uniform distribution near the top surface of the liquid. Gas holdup values are increased with increasing the impeller speed and gas flow rate and decreased with the bubble diameter.

SCIENTIFIC AND ENGINEERING PRINCIPLES OF EFFICIENT FUEL USE AND ENVIRONMENTALLY FRIENDLY GAS COMBUSTION IN STOVE PLATES. PART 1. MODERN STATE-OF-THE-ART AND DIRECTIONS FOR IMPROVEMENT THE GAS BURNING IN DOMESTIC GAS COOKERS

2017 ◽  
pp. 3-18 ◽  
Author(s):  
B.S. Soroka ◽  
V.V. Horupa
Keyword(s):  
Natural Gas ◽  
Flow Rate ◽  
Gas Flow ◽  
Renewable Energy Sources ◽  
Combustion Process ◽  
Orifice Diameter ◽  
Firing Process ◽  
Gas Flow Rate ◽  
Gas Combustion ◽  
Gas Stoves

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.

On the Influence of Fluctuating Flow Rate Upon the Performance and Behaviour of Isothermal Reacting Systems

1998 ◽  
Vol 63 (6) ◽  
pp. 881-898
Author(s):  
Otakar Trnka ◽  
Miloslav Hartman
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Fluidized Bed Reactor ◽  
Computational Techniques ◽  
Continuous Stirred Tank Reactor ◽  
Gas Flow Rate ◽  
Solid Reaction ◽  
Continuous Stirred Tank ◽  
And Performance ◽  
Reacting Systems

Three simple computational techniques are proposed and employed to demonstrate the effect of fluctuating flow rate of feed on the behaviour and performance of an isothermal, continuous stirred tank reactor (CSTR). A fluidized bed reactor (FBR), in which a non-catalytic gas-solid reaction occurs, is also considered. The influence of amplitude and frequency of gas flow rate fluctuations on reactant concentrations at the exit of the CSTR is shown in four different situations.

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