Damage areas during emergency depressurization of a gas pipeline

Evgenia Varsegova,Renat Sadykov,Elena Dresvyannikova,Lilia Osipova,N Vatin,P Zunino,E Vdovin

doi:10.1051/e3sconf/201914006007

Evgenia Varsegova, Renat Sadykov + Show 5 more

Open Access

https://doi.org/10.1051/e3sconf/201914006007

Copy DOI

Abstract

Main gas pipelines are classified as energetically stressed objects. With an increase in their service life, there appears a need to model emergency breaks and analyze the distribution of the damaging factors of the accident. The main gas pipelines often run near residential areas and cross various communications, therefore possible accidents with gas emissions and damaging factors can negatively affect both the environment and the population. An emergency rupture of a gas pipeline section is numerically modeled in this article. The calculations of intensity of accidental gas emissions outflow and distribution of the accident damaging (the length of the methane jet in unlimited airspace, the range and height of the scattering of the soil and pipe fragments were found). The parameters of free jets of exhaust gas were determined. Such calculation is required during investigation of accidents and development of documents related to the environmentally safe operation of pipeline transport. In case of gas non-ignition, it disperses in the atmosphere with the formation of gas zones. The study of the influence of velocity, density and pressure on the emergency gas emission allows us to determine possible gas contamination zones. Graphs of distribution of static and total pressure over the ejection height, distribution of velocities along the axis of the ejected jet and along the axis of the pipeline were obtained. The ability to evaluate the parameters of free jet flow of natural gas (methane) from a damaged pipeline: the total flow rate, total pressure and flow rate at the rupture point is relevant in solving applied environmental safety problems of gas transportation facilities.

Highlights

Natural gas is one of the most widespread energy source material, so the analysis of possible gas pipeline ruptures determines the technogenic safety of energy objects of gas transport and increases the energy security of the population
PJSC Gazprom recommends calculating the damaging factors from emergency gas emissions according to the STO Gazprom 2-2.3-351-2009 methodology, in which the zone of the damaging factors action determines the intensity of the outflow
We modeled the “guillotine” rupture of the pipeline section at the full cross section (Fig. 1 a)

Summary

Introduction

Natural gas is one of the most widespread energy source material, so the analysis of possible gas pipeline ruptures determines the technogenic safety of energy objects of gas transport and increases the energy security of the population. In [4], a mathematical model for describing the turbulent distribution of gas emissions through organized pollution sources using the ANSYS (FLUENT) software package was proposed. PJSC Gazprom recommends calculating the damaging factors from emergency gas emissions according to the STO Gazprom 2-2.3-351-2009 methodology, in which the zone of the damaging factors action determines the intensity of the outflow. To solve such applied problems, methods of computational fluid dynamics using the ANSYS (FLUENT) software package are widely used. The use of turbulence models to solve these tasks is described in [20–22]

Problem statement

Mathematical model

Results and Discussion

Conclusions