Analysis of crater formation in buried NG pipelines: A survey based on past accidents and evaluation of domino effect

Abstract

The formation of a crater by the abrupt and catastrophic rupture of a high-pressure pipeline can be highly relevant, especially when the crater uncovers other pipelines, which could undergo a domino effect with a significant increase of the consequences on people or on the environment. However, this scenario has been only partially studied in the literature. To assess the influence of the pipeline parameters on the dimensions of the resulting crater, a statistical analysis of accidental ruptures of buried natural gas pipelines that have involved the formation of a crater was carried out. Mathematical expressions are proposed to describe the proportionality relationships found, which can be very useful to support adequate separation distances in the design and construction of parallel corridors of pipelines after appropriate escalating effects are considered. Finally, detailed event trees were developed to calculate the probability of occurrence of the final outcomes, as well as the identified domino sequences, based on a qualitative and quantitative analysis of the data. The study of these accident scenarios, based on actual cases, represents a useful and needed advance in risk analysis of natural gas transportation through pipelines.

Evaluation of LES sub-grid scale models and time discretization schemes for prediction of convection effect in a buoyant pool fire

“…As seen in Fig. (4), the prediction of WALE and one equation SGSs are better than that of Smagorinsky SGS. Smagorinsky SGS, that uses constant coefficient for the filter, has less consistency with the experimental results.…”

“…The pool fire, where samples can be seen abundantly in natural fires [2], is a reactive plume flow with low kinetic energy, where buoyancy force is the dominant force on its motion [3]. Contrary to a pool fire, the momentum force is dominating in a jet fire [4]. Pool fire modeling represents the most basic case to investigate a fire modeling process.…”