91 NUMERICAL ANALYSIS NUMERICAL ANALYSIS OF METHANEAIR
2010 MOREHEAD STATE VOLLEYBALL NUMERICAL ROSTER NO NAME POS91 NUMERICAL ANALYSIS NUMERICAL ANALYSIS OF METHANEAIR
ABSTRACT THE OBJECTIVE OF THIS ARTICLE IS NUMERICAL AND
AIAA992189 NUMERICAL PREDICTION OF TRANSIENT AXIAL THRUST AND INTERNAL
APP B22 APPENDIX B—NUMERICAL INDEX OF DISABILITIES APP B22
BENCHMARK NUMERICAL SOLUTIONS FOR RADIATIVE HEAT TRANSFER IN TWODIMENSIONAL
NUMERICAL ANALYSIS OF METHANE-AIR POLLUTION
________________________________________________________________________
NUMERICAL ANALYSIS OF METHANE-AIR POLLUTION
Skiteva I., Seleznev V.
Computation Mechanics Technology Center, Russia
Abstract: The method described in the paper is meant for enhancing fire safety of gas industry and proposes to use numerical simulation for analysis of methane-air mixture combustible clouds propagation and for prevention of fires and explosions. Method is based on numerical solution of Reynolds equations. The particular examples are presented for safety analysis of natural gas distribution stations.
1. Introduction
Gas industry includes fire and explosive risk industrial facilities. Deterioration of pipelines and violation of the standard modes of gas pipeline equipment operation lead to increase in number of failures entailing emission of transmitted gases and being the cause of the intense fires. The method described in the paper is meant for enhancing fire safety of gas industry and proposes to use numerical simulation for analysis of methane-air mixture combustible clouds propagation and for prevention of fires and explosions. Method is based on numerical solution of Reynolds equations. Solution is carried out by grid methods. Material presentation is executed by Russian and Slovak Gas-Distributing Stations (GDS). The paper presents the particular examples of safety analysis for GDS.
2. Mathematical Models
Numerical simulation problem
concerned with natural gas emission from failure gas transmission
pipeline and methane-air clouds propagation inside the buildings and
at the territory of GDS proposes defining the relative mass fraction
fields of methane in the area of jet emission as a result of
numerical analysis of Reynolds’ fluid dynamics equations
completed by
or
turbulence model and corresponding to boundary conditions. These
boundary conditions describe [1]: atmospheric state, terrain,
structure of buildings, geometry of the emission source. The geometry
of the emission source is determined basing on the results of
numerical simulation of pipeline rupture.
Multicomponent gas mixture flow is simulated in diffusion approximation providing necessary (from the view of industrial problem solution) accuracy. Mathematical model of this flow has the following view in Cartesian coordinate system:
(1)
(2)
(3)
(4)
(5)
;
(6)
(7)
(8)
(9)
,
(10)
where
– mixture density;
– piezometric pressure;
– temperature;
– velocity with the components
;
– molecular diffusivity;
;
– Schmidt number;
– relative mass fraction of m-component
(
– density of m-component
of mixture);
- number of components in gas mixture (in our case -
(air and methane));
– gravitational acceleration;
– time;
- nabla operator;
- substantial derivative from scalar function; notation of
substantial derivative from vector function means substantial
derivation of vector function components;
– total enthalpy, where
- enthalpy for ideal gas,
– specific heat capacity at constant pressure;
–
specific heat capacity at constant volume;
- thermal conductivity;
- turbulent conductivity;
- dynamic viscosity;
– Sutherland constant;
- dynamic viscosity under the normal conditions;
- turbulent viscosity;
– heat generation rate;
– gas constant;
- Cartesian coordinates of the point (
- coordinate being on the vertical axis, directed from the center of
the Earth);
- fixed coordinate corresponding to the sea level;
- viscous stress tensor;
- Kronecker delta;
- turbulence dissipation rate;
- kinetic turbulence energy;
- empirical constants;
- Prandtl number; inferior index
means “turbulent”; inferior index “atm”
means “atmosphere”;
- universal gas constant;
- known semi-empirical functions. It is proposed to use the following
constants’ values in (6):
;
;
;
;
;
.
If gas flows are simulated close to impermeable surfaces, so the
system of equations (6) is added by well known near the wall layer
logarithmic functions.
The following boundary conditions are used to complete the above mentioned system of equations:
on the boundaries of the computational domain where gas is emitted from the pipeline into the atmosphere: kinetic turbulence energy; its dissipation rate and conjugation conditions that connect mass flow rate, pressure, temperature and relative mass fractions (these parameters of the failure pipelines are defined at each time step as a result of CFD-simulator of GDS piping operation [1]);
on the terrain and crater surfaces: conditions corresponding to impermeable adiabatic stationary wall;
on the “inlet” side boundary: the field of the wind; relative mass fractions; temperature; kinetic turbulence energy and its dissipation rate;
on the “outlet” side boundary: piezometric pressure; diffusion fluxes of temperature, relative mass fractions, kinetic turbulence energy and its dissipation rate;
on the upper boundary and on the “passive” side boundaries: piezometric pressure; temperature and relative mass fractions, kinetic turbulence energy and its dissipation rate (if gas flows into the computational domain through this boundary); if gas outflows, so there are the outlet boundary conditions.
Quasi-steady state distributions of fluid flow
parameters are initial parameters if these distributions satisfying
the boundary conditions, i.e. there is not outflow of gas from the
failure pipeline.
turbulence model without near the wall layer function (as in
turbulence model), is proposed to be used for correct
description of these processes and for enhancing adequacy of plume
emission simulation. It is used while completing Reynolds equations
[2]. Method of finite volumes
and fluid in cells method are used to solve the stated problem (1-10)
and for enhancing reliability of the obtained computational
estimations [1].
Numerical analysis of fire or explosion risk at GDS proposes investigating simulation of natural gas emission into the environment at different time steps. Formation of gas-air mixture clouds with dangerous concentration at the territory of GDS are considered as the criterion of fire risk at GDS. Fire and explosion risk zones (including asphyxiating effect of methane on people) and the ways for safe evacuation of personnel are marked on the topographic map of GDS.
Numerical analysis of the ways for fire or explosion prevention at GDS is applied for estimation of the following measures, namely: control for combustible gas accumulation at the territory of GDS, aeration of buildings, anticipatory retardation of fire risk and explosive medium. These measures are meant for fire or explosion risk reduction.
Fig.1. Relative mass fraction field of methane - 1,1s after the beginning of its emission from the failure pipeline
3. Results
Let us consider the application results of the stated earlier method for analysis of methane-air clouds propagation. We will consider these results by the example of failure methane emission at actual GDS belonging to SPP International Gas Transmission Company (Slovakia).
Fig. 1 presents the field of relative mass fraction of methane. It was obtained by numerical simulation of methane emission from the failure pipeline accounting the field of the wind and geometry of neighboring buildings situated in the considered GDS. The technology for structural analysis of pipelines developed by Dr. Vladimir Aleshin is used for analysis of emission source geometry [1].
(a) (b)
Fig.2. (a) dispatching point of GDS; (b) geometry of computational domain of the operators’ office (1 – store room, 2 – WC, 3 – lounge, 4 – control room, 5 – hall)
It was concluded that it is possible to neglect the buoyancy effect of gas cloud if the wind velocity in the earth surface area exceeds 10m/s. Let us consider the example of effective operation analysis of anticipatory retardation system in the GDS operators’ office which is filled with methane-air mixture through the windows caused by failure natural gas emission. Fig. 2 presents the general view of the operators’ office and its analytical model. Fig. 3 presents relative mass fraction field of the retarder (nitrogen) applied in the operators’ office.
Fig.3. Field of relative mass fractions of retarder while its supply into the building filled with fire risk and explosive methane-air mixture (time – 10s after beginning of the retarder supply)
(a) (b)
Fig.4 Mass fractions of methane and retarder in mixture in computational grid nodes. Time – 70 sec (a) and 254 sec (b) after the beginning of mixture dilution with nitrogen
Fig. 4 presents mass fractions of the mixture components for all nodes of the computational grid of the operators’ office. Mass fractions are presented in the following coordinates: “methane content in the mixture with air and nitrogen” and “nitrogen content in the mixture with air”. Diagrams are presented for time 70s after the beginning of retarder feeding into the building. The area of composition mass fraction and restricted by the retardation curve and axis of ordinates is combustible area, but the area beyond the retardation curve is noncombustible one. Simulation results have shown that mixture becomes noncombustible in 254s after the beginning of dilution of mixture with nitrogen (see Fig.4,b).
4. Concluding Remarks
The paper describes effective method for numerical analysis of methane-air clouds’ formation and propagation at the territory of GDS while technological gas pipeline ruptures. Application results of this method are used to create the scenarios of failures at GDS, to estimate their consequences, and to develop scientifically justified methods for avoiding similar failures and their consequences including ignition of gas-air mixtures or their explosion.
References
Seleznev V.E., Aleshin V.V. et al.: Numerical simulation of gas pipeline networks: theory, computational implementation, and industrial applications. Ed. by V.E. Seleznev. – Moscow: KomKniga, p.720, 2005.
Seleznev V., Aleshin V.: Computation technology for safety and risk assessment of gas pipline systems. Proceedings of the Asian International Workshop on Advanced Reliability Modeling (AIWARM’2004), (August 2004, Hiroshima City, Japan). – World Scientific Publishing Co. Pte. Ltd., London, p.443-450, 2004.
CHAPTER 12 STOICHIOMETRY STOICHIOMETRY DEALS WITH NUMERICAL RELATIONSHIPS IN
CHAPTER 4 NUMERICAL METHODS IN LINEAR ALGEBRA 41 EIGENVALUES
CITE KCASKCCT STANDARD NUMERICALLY ONLY ON THIS GUIDE CURRICULUM
Tags: analysis ..., numerical analysis, numerical, analysis, methaneair
- PETERSTON SUPER ELY COMMUNITY CONSULTATION CREATIVE RURAL COMMUNITIES
- SMERNICE ZDRAVEGA IN UČINKOVITEGA PREHRANJEVANJA MLADOSTNIKOV V NAJSTNIŠKIH LETIH
- BRUNO HAUZAREE JR ENG BRUNOHAUZAREEGMAILCOM SENIOR ARCHITECT ARCHITECT IT
- BM ORSZÁGOS KATASZTRÓFAVÉDELMI FŐIGAZGATÓSÁG BUDAPEST 2016 JÚNIUS 24 TÁJÉKOZTATÓ
- PSICOLOGÍA DE LA INSTRUCCIÓN ASIGNATURA DE 1º CURSO DE
- WHEN TRENDS CAN MISLEAD THE RISE FALL AND
- TEMPO RUNS TEMPO RUNS ARE MEANT TO HELP INCREASE
- ESSAY BEGINNINGS AND ENDINGS USEFUL SENTENCES TO BEGIN
- IDENTIFYING HIGH INFILTRATION AND GROUNDWATER RECHARGE AREAS IN DANE
- AYUNTAMIENTO DE VILLAMAÑAN PZA MAYOR SN 24234VILLAMAÑAN LEÓN TELÉFONO
- VSEVOLOD Y MARTSENYUK MARCH 31 2001 ADDRESS
- HARMONOGRAM 2 SZKOLENIA „EDUKATOR PROFILAKTYKI UZALEŻNIEŃ I STOPNIA”
- EDUCATING THE WORKFORCE ABOUT THE ADA AND ACCOMMODATIONS EFFECTIVE
- XXX REDOVNO SAVJETOVANJE IMPLEMENTACIJA EUROPSKIH KONVENCIJSKIH STANDARDA U HRVATSKO
- CITY OF ALLENTOWN SNOW EMERGENCY ROUTES STREET FROM TO
- BUILDING ANDOR MACHINERY LEASING AGREEMENT THIS AGREEMENT MADE IN
- INFORME DEL CONFLICTO ENTRE MARRUECOS Y EL SAHARA EL
- ZAHTJEV ZA SMJEŠTAJ U DOM ZA STARIJE OSOBE “MARKO
- (INSTITUCIÓN) BASES DE CONCURSO DEFINICIÓN ES EL DOCUMENTO
- KSIĄŻKI POSZUKIWANE STAN NA 22102015 1 GUERRA EXILIO DIÁSPORA
- UPOVEXNEDV2 DRAFT 3 PÁGINA 12 S UPOVEXNEDV2 DRAFT 3
- MILYEN SZENTÍRÁSI KÖNYVEK RÖVIDÍTÉSEIT TALÁLOD MEG A MONDATBAN? 1
- IZJAVA O SUKLADNOSTI PREMA NORMI EN 17050 MI TVRTKA
- LEI Nº 1609 DE 29 DE DEZEMBRO DE 1992
- Ðïࡱáþÿ ¥áa𿱠Bjbjôô8¾ëh¾ëh£ Ÿÿÿÿÿÿ·òòx8fx8fx8fx8fx8fÿÿÿÿ£££8ûd£6bµ······x98¶n2|ûx8fûx8fx8fûð×××x8ex8fx8fµ×µ××r©(t©ÿÿÿÿðïßskùÿÿÿÿíý)¡06x9eê2^ê2©©8ê2x8fáàvx8ct×àdûûy^ U
- SAFETY GUIDELINES FOR EDUCATION OUTDOORS DOCUMENTATION OF STAFF
- PROGRAMA AULA DE INNOVACIÓN CONFERENCIA “LAS OPORTUNIDADES
- 2252015 DATE SOCIAL SCIENCE DIVISION X REQUIRED COURSE NEW
- how to Create Audio (mp3) Files for use Within
- VERSIE JULI 2004 BEOORDELINGSKADER ACCREDITATIE BIJ EN NASCHOLINGSBIJEENKOMSTEN
APÉNDICE A TABLA DE HALLAZGOS DEL SITIO 362 [H1
MEETING OF THE MINISTERS OF FOREIGN AFFAIRS WITH REPRESENTATIVES
CHRONIC OBSTRUCTIVE PULMONARY DISEASE CHRONIC OBSTRUCTIVE PULMONARY DISEASE IS
01127ABRIL1933 DECRETO QUE REFORMA LA FRACCIÓN X DEL ARTÍCULO
SÍNTESIS DE LA LÍNEAS DE TRABAJO ELABORADAS EN EL
20 DIÁLOGOS UNES ALTRES VEUS CASTELLANO OTRAS VOCES ALBERT
CURSOS EN TECNOLOGÍA DE LA INFORMACIÓN Y LAS COMUNICACIONES
NOMBRE FECHA PROBLEMAS 1 SE HANINSTRUKTIONOPLÆRING OG TILSYN EKSEMPEL – TILPAS EFTER VIRKSOMHEDENS FORHOLD
7 YEAR OLD KINDER BIWEEKLY LESSON PLAN CLASS &HRVATSKI SINDIKAT ŠUMARSTVA ZAGREB TRG KRALJA PETRA KREŠIMIRA IV
7TH “ITALIAN LANGUAGE WEEK WORLDWIDE” THE ITALIAN LANGUAGE AND
FEDERAL PROCUREMENT DATA SYSTEM – NEXT GENERATION (FPDSNG) WEBX Z I B S H G Z E
NIL EQUIVALENT DAN ZERO EQUIVALENT PADA TERJEMAHAN FOLKLOR SASTRA
DYNAMIC PRICE COMPETITION IN HOMOGENOUS PRODUCTS CHICAGO TRADITION ON
SMALL MS4 ANNUAL REPORT FORM STATE OF OHIO ENVIRONMENTAL
S Ø K N A D OM KONSESJON TILREGULAMIN PRACY PRZEDSZKOLA PUBLICZNEGO NR 5 IM „ KUBUSIA
THE ORANGE WALLET – BUS STAFF GUIDE WHAT IS
