Numerical study of gas leakage from a pipeline and its concentration evaluation based on modern and practical leak detection methods

Abstract

Gas leaks from pipelines may cause human casualties and economic losses. Consequently, detecting gas diffusion in the environment and determining its concentration around pipelines can be essential. In the present research, leakage of natural gas due to the failure of pipelines is studied in both air and porous environments using three-dimensional simulations. Besides, the effective factors in increasing the concentration of exhaust gas in each of these environments have been investigated. Moreover, the effect of these factors on the explosion area is examined. To ensure the accuracy of the numerical method, with the aid of Isfahan Gas Company in Iran, a real leakage sample was tested, and a comparison of the experimental result with the numerical solution was carried out. Factors such as pipeline pressure, rupture diameter, wind velocity, and soil porosity are influential factors in the studied problem. The results of this simulation show that by increasing the pipeline pressure (413.68, 1723.68, 7239.4 Kpa) and increasing the diameter of the leak rupture (20, 50, 100 mm), an increase in the height of the explosion area will be induced. Further, the effect of wind velocity on the gas jet concentration has been examined. It was revealed that increasing the wind velocity reduces the height of the explosion area. Finally, by performing the simulation in a porous medium, it was concluded that increasing the soil porosity (0.1, 0.4, 0.7, 1) extends the explosion area.