Numerical Simulation of Natural Gas Dispersion from Low Pressure Pipelines
Gas release from the pipelines is one of the main factors in the gas industry accidents. Released gas ejects from the pipeline as a free jet and in the growth process, the fuel gets mixed with the ambient air. Accordingly, an accidental spark will release the chemical energy of the mixture with an explosion. Gas explosion damages the equipment and endangers the life of staffs. So due to importance of safety in gas industries, prevision of accident can reduce the number of the casualties. In this paper, natural gas leakages from the low pressure pipelines are studied in two steps: 1) the simulation of mixing process and identification of flammable zones and 2) the simulation of wind effects on the mixing process. The numerical simulations were performed by using the finite volume method and the pressure-based algorithm. Also, for the grid generation the structured method was used. The results show that, in just 6.4 s after accident, released natural gas could penetrate to 40 m in vertical and 20 m in horizontal direction. Moreover, the results show that the wind speed is a key factor in dispersion process. In fact, the wind transports the flammable zones into the downstream. Hence, to improve the safety of the people and human property, it is preferable to construct gas facilities and buildings in the opposite side of prevailing wind direction.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1315765Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 930
 A. Golara, A. Esmaeily, “Quantification and enhancement of the resilience of infrastructure networks”. Journal of Pipeline Systems Engineering and Practice, vol. 8, no. 1, pp. 1-10.
 A. Golara, H. Bonyad, and H. Omidvar, “Forecasting Iran’s natural gas production, consumption”, Pipeline & Gas Journal, vol. 242, no. 8, pp. 24-30, 2015.
 S. Sklavounos, F. Rigas, “Estimation of safety distances in the vicinity of fuel gas pipelines”, Journal of Loss Prevention in the Process Industries, vol. 19, no. 1, pp. 24-31, (2006).
 H. Wilkening, D. Baraldi, “CFD modelling of accidental hydrogen release from pipelines”, International Journal of Hydrogen Energy, vol. 32, no. 13, pp. 2206-2215, 2007.
 Q. Hou, W.Jiao, “Improved FDS analysis for the atmospheric impact of natural gas leakage and diffusion”, Journal of Computational Information Systems, vol. 7, no. 13, pp.4702-4709, 2011.
 O. Adibi, A. Azadi, B. Farhanieh, and H. Afshin, “A parametric study on the effects of surface explosions on buried high pressure gas pipelines”, Engineering Solid Mechanics, vol. 5, no. 4, pp. 225-244, 2017.
 R. Khaksarfard, M. R. Kameshki, and M. Paraschivoiu, “Numerical simulation of high pressure release and dispersion of hydrogen into air with real gas model”, Shock Waves, vol. 20, no. 3, pp. 205-216, 2010.
 J. Choi, N. Hur, S. Kang, E. D. Lee, and K. B. Lee, “A CFD simulation of hydrogen dispersion for the hydrogen leakage from a fuel cell vehicle in an underground parking garage”, International Journal of Hydrogen Energy, vol. 38, no. 19, pp. 8084-8091, 2013.
 H. Meysami, T. Ebadi, H. Zohdirad,and M. Minepur, “Worst-case identification of gas dispersion for gas detector mapping using dispersion modeling” Journal of Loss Prevention in the Process Industries, vol. 26, no. 6, pp. 1407-1414, 2013.
 A. N. Borujerdi, M. Z. Rad, “Numerical modeling of transient turbulent gas flow in a pipe following a rupture” Scientia Iranica. Transaction B, Mechanical Engineering, vol. 17, no. 2, pp. 108-120, 2010.
 X. Liu, A. Godbole, C. Lu, G. Michal, and P. Venton, “Source strength and dispersion of CO 2 releases from high-pressure pipelines: CFD model using real gas equation of state”. Applied Energy, vol. 126, pp. 56-68, 2014.
 O. Adibi, B. Farhanieh, and H. Afshin, “Numerical study of heat and mass transfer in underexpanded sonic free jet”, International Journal of Heat and Technology, vol. 35, no. 4, pp. 959-968, 2017.
 J. Wendt, “Computational fluid dynamics: an introduction”, Springer Science & Business Media, 2008.
 S. B. Pope, “Turbulent flows”, Cambridge university press, 2009.
 B. E. Launder, D. Spalding, “The numerical computation of turbulent flows”, Computer methods in applied mechanics and engineering, vol. 3, no. 2, pp. 269-289, 1974.
 V. Venkatakrishnan, J. M. Dimitri, “Implicit solvers for unstructured meshes”, Journal of computational Physics, vol. 105, no. 1, pp. 83-91, 1993.
 S. M. Tauseef, D. Rashtchian, S. A. Abbasi, “CFD-based simulation of dense gas dispersion in presence of obstacles” Journal of Loss Prevention in the Process Industries, vol. 24, pp. 371–376, 2011.