Study of quantification and distribution of explosive mixture in a confined space as a result of natural gas leak

¹ VSB – Technical University of Ostrava, Faculty of Safety Engineering, Department of Fire Protection, Lumírova 630/13, Ostrava - Výškovice, 700 30, The Czech Republic
² VSB – Technical University of Ostrava, Faculty of Mechanical Engineering, Department of Hydromechanics and Hydraulic Equipment, 17.listopadu 15/2172, Ostrava - Poruba, 708 33, The Czech Republic

^a Corresponding author: miroslav.mynarz@vsb.cz

Published online: 25 March 2014

Abstract

The contribution deals with quantification of natural gas leak from a domestic low pressure pipe to a confined space in relation to formation of explosive concentration. Within the experiments, amount of leak gas was determined considering the character of pipe damage. Leakage coefficients, natural gas expansion and time before reaching the lower explosive limit of a gas-air mixture were taken. Conducted experiments were then modelled using CFD software and the results were verified. In numerical model, several models of flow were used and afterwards following issues were analysed: leakage velocity, spatial distribution of the mixture in a confined space, formation of concentration at the lower explosive limit etc. This work should contribute to better understanding of propagation and distribution of gaseous fuel mixtures in confined spaces and thereby significantly reduce the risk of fires or explosions or prevent them.