Numerical simulation of the stress state of an erosion-worn tee of the main gas pipeline

2020 ◽  
Vol 2 (101) ◽  
pp. 63-78
Author(s):  
Ya. Doroshenko ◽  
V. Zapukhliak ◽  
Ya. Grudz ◽  
L. Poberezhny ◽  
A. Hrytsanchuk ◽  
...  

Purpose: To investigate the strength of tees with regard to their erosion wear, it is necessary to consider the complex three-dimensional geometric shape of the erosion worn inner surface of the tee. In addition, the study of the strength of the erosion worn tees of the main gas pipelines is complicated by the occurrence of additional stresses caused by changes in the direction of movement of the gas stream, resulting in an uneven pressure distribution in the inner cavity of the tee, and the temperature difference in its walls. Design/methodology/approach: Methodology for complex numerical three-dimensional simulation of the stressed state of tees of the main gas pipelines, taking into account the gas-dynamic processes that occur in the places of these defects, erosion wear of the tee wall, temperature difference in the tee walls. Findings: The acceptable parameters of erosion defects of tees of gas pipelines, and residual life of tees with erosion defects of the wall should be determined. Research limitations/implications: The developed model does not take into account internal corrosion and corrosion products as an additional erosion factor. Further studies plan to develop a model of corrosion-erosion wear of pipeline elements. Practical implications: The developed technique allows determining the location of erosion defects, estimating the strength and determining the residual life of tees with erosion wear of the wall in order to ensure their reliability, to rank such defects according to the degree of danger, to determine which of them are critical and need an immediate repair. Originality/value: Based on the gas-dynamic processes occurring in the internal cavity of the main gas pipelines’ tees, the complex three-dimensional geometric form of wall erosion defects, and temperature difference, the technique of three-dimensional simulation of stress state of the main gas pipelines’ tees is developed.

2021 ◽  
Vol 71 (1) ◽  
pp. 27-40
Author(s):  
Doroshenko Yaroslav ◽  
Kogut Galyna ◽  
Doroshenko Yuliia ◽  
Tarayevs’kyy Oleh ◽  
Pyrig Taras

Abstract The purpose of this work is to ensuring the strength of main gas pipelines bends by studying the peculiarities of single-phase and multiphase flows movement through the internal cavity, the processes of erosion wear and the wall stress state. The problem of synergistic influence of gas-dynamic processes (uneven pressure distribution in the internal cavity), temperature difference and erosion wear on the stress state of the bends of main gas pipelines was solved by numerical simulation. Based on the results of simulation the processes of bends erosion wear, an algorithm for three-dimensional simulation of bend walls erosion defects was developed. The complex three-dimensional geometric shape of the erosion defects of the bend wall varied according to the rate of erosion wear process. This algorithm made it possible to determine the regularities for the influence of the bend erosion defects magnitude on bends stress state. It was established that considering the maximum depth of bend erosion defects 9.6 mm, 10.5 mm and 11.9 mm, the equivalent stresses in the deepest places of the erosion defect were greater than on the concave side of the bend and in straight sections of the pipeline.


2021 ◽  
Vol 22 (3) ◽  
pp. 551-560
Author(s):  
Ya.V. Doroshenko ◽  
G.М. Kogut ◽  
I.V. Rybitskyi ◽  
O.S. Tarayevs'kyy ◽  
T.Yu. Pyrig

The purpose of this work is to ensuring the strength of main gas pipelines bends by studying the peculiarities of single-phase and multiphase flows movement through the internal cavity, the processes of erosion wear and the wall stress state. The problem of synergistic influence of gas-dynamic processes (uneven pressure distribution in the internal cavity), temperature difference and erosion wear on the stress state of the bends of main gas pipelines was solved by numerical simulation. Based on the results of simulation the processes of bends erosion wear, an algorithm for three-dimensional simulation of bend walls erosion defects was developed. The complex three-dimensional geometric shape of the erosion defects of the bend wall varied according to the rate of erosion wear process. This algorithm made it possible to determine the regularities for the influence of the bend erosion defects magnitude on bends stress state. It was established that considering the maximum depth of bend erosion defects 9.6 mm, 10.5 mm and 11.9 mm, the equivalent stresses in the deepest places of the erosion defect were greater than on the concave side of the bend and in straight sections of the pipeline.


2019 ◽  
Vol 6 (1) ◽  
pp. 14-21
Author(s):  
Ya.V. Doroshenko

The research has been carried out for the purpose of a complex numerical three-dimensional modeling of the stressed state of taps and tees of main gas pipelines taking into account the gas-dynamic processes occurring in these shaped elements and the temperature difference in their walls. A 3D modeling of the elbow with a 90° angle and a reinforcing pad on the main line and the drainage of the passage line of the trunk of the main gas pipeline has been carried out. There has been studied the gas flow with 3D models of shaped elements of the main gas pipeline by means of the CFD modeling. The simulation has been рerformed for the equidistant tees in which the entire flow from the main stream flows into its branch. The mathematical model is based on the solution of the Navier–Stokes equation system, continuity equation, closed by a two-parametric k -e model of the Launder–Sharma turbulence with corresponding initial and boundary conditions. The simulation results are visualized in the ANSYS Fluent R18.2 Academic Postprocessor by constructing the pressure fields on the contours and in the longitudinal and transverse sections of shaped elements. The exact values of pressure at different points of the inner cavity of the shaped elements have been determined, the places of rise and fall of pressure identified. There have been performed the simulation of the temperature difference in the walls of the drainage, the trunk of the main gas pipeline in the module ANSYS Transient Thermal. The results of CFD and temperature modeling were imported into the mechanical module ANSYS Static Structural, where the finite element method was used to simulate the stressed state of the shaped elements of the main gas pipeline, taking into account the gas-dynamic processes occurring in their internal cavity and the temperature difference in the walls. The results of the simulation have been visualized by constructing a three-dimensional color fields of equivalent von Mises stresses in the tee and in the elbow. The places of the maximum equivalent stresses in the wall of the studied shaped elements have been revealed. 


Author(s):  
V.B. Volovetskyi ◽  
Ya. Doroshenko ◽  
G. Kogut ◽  
A.P. Dzhus ◽  
I.V. Rybitskyi ◽  
...  

Purpose: The article implies theoretical and experimental studies of the liquid pollution accumulations impact on the efficiency of gathering gas pipelines operation at the Yuliivskyi oil and gas condensate production facility (OGCPF). Research of efficiency of gas pipelines cleaning by various methods. Design/methodology/approach: The research methodology consists of determining the hydraulic efficiency of gathering gas pipelines before and after cleaning of their internal cavity by different methods and comparing the obtained results, which allows to objectively evaluate the efficiency of any cleaning method. CFD simulation of gas-dynamic processes in low sections of gas pipelines with liquid contaminants. Findings: Experimental studies of cleaning efficiency in the inner cavity of the gas gathering pipelines of the Yuliivskyi OGCPF by various methods, including: supply of surfactant solution, creating a high-speed gas flow, use of foam pistons were performed. It was established that cleaning the inner cavity of gas gathering pipelines by supplying a surfactant solution leads to an increase in the coefficient of hydraulic efficiency by 2%-4.5%, creating a high-speed gas flow by 4%-7%, and under certain conditions by 8%-10 % and more. However, for two gas pipelines the use of foam pistons allowed to increase the coefficient of hydraulic efficiency from 5.7 % to 10.5 % with a multiplicity of foam from 50 to 90. be recommended for other deposits.The results of CFD simulation showed that the accumulation of liquid contaminants in the lowered sections of gas pipelines affects gas-dynamic processes and leads to pressure losses above the values provided by the technological regime. With the increase in liquid contaminants volume the pressure losses occur. Moreover, with a small amount of contamination (up to 0.006 m3), liquid contaminants do not have a significant effect on pressure loss. If the contaminants volume in the lowered section of the pipeline is greater than the specified value, the pressure loss increases by parabolic dependence. The increase in mass flow leads to an increase in the value of pressure loss at the site of liquid contamination. Moreover, the greater the mass flow, the greater the impact of its changes on the pressure loss. The CFD simulation performed made it possible not only to determine the patterns of pressure loss in places of liquid contaminants accumulation in the inner cavity of gas pipelines, but also to understand the gas-dynamic processes in such places, which is an unconditional advantage of this method over experimental. Research limitations/implications: The obtained simulation results showed that the increase in the volume of liquid contaminants in the inner cavity of gas gathering pipelines leads to an increase in pressure losses above the value provided by the technological regime. To achieve maximum cleaning of gas gathering pipelines, it is necessary to develop a new method that will combine the considered. Practical implications: The performed experimental results make it possible to take a more thorough approach to cleaning the inner cavity of gas gathering pipelines and to forecast in advance to what extent the hydraulic efficiency of gas gathering pipelines can be increased. Originality/value: The obtained results of CFD simulation of gas-dynamic processes in lowered sections of gas pipelines with liquid contaminants, experimental studies of the effectiveness of various methods of cleaning the inner cavity of gas gathering pipelines has original value.


2007 ◽  
Vol 26-28 ◽  
pp. 947-952 ◽  
Author(s):  
Jing Yu ◽  
Qing Yan Xu ◽  
Bai Cheng Liu ◽  
Jia Rong Li ◽  
Hai Long Yuan

A mathematical model for three-dimensional simulation of unidirectional solidification process and microstructure evolution of Ni-based superalloy investment castings was developed based on CA-FD method. The modified ray tracing method was used to solve the complicated heat radiation transfer among the multiple blades and outer space during withdrawal process. Various withdrawal rates were used. During one process high withdrawal rate was used first before the platform approached the baffle. Then the low withdrawal rate was used to reduce the temperature difference of the platform in horizontal section and avoid the defects formed in the corner of the platform. The experimental cooling curves of different positions in the blades and microstructure were compared with the simulation results. Both the results showed that the various withdrawal rates process was effective to reduce the temperature difference of the platform and avoid the formation of stray grains. This process could be helpful to increase the productivity.


2008 ◽  
Vol 128 (2) ◽  
pp. 459-466 ◽  
Author(s):  
Yoshitaka Inui ◽  
Tadashi Tanaka ◽  
Tomoyoshi Kanno

2009 ◽  
Vol 19 (1) ◽  
pp. 75-90 ◽  
Author(s):  
Hong-Bing Xiong ◽  
Jian-Zhong Lin ◽  
Ze-Fei Zhu

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