GAS EXPLOSION MODELLING AND SIMULATION

Abstract

CFD-based study has been conducted to investigate the IOCL 2009 accident which may prove useful while designing safety measures for a similar plant. FLACS package is used to model the worst-case scenarios with four leak rates 10 kg/s to 100 kg/s. Various parameters have been calculated for the aforementioned leak rates, while employing both dispersion and explosion modeling. Dispersion results obtained, principally, pertain to diameters, average heights and volumes of the vapor cloud at different leak rates. Semi-Empirical (TNT and multi-energy) methods are used to estimate the total potential explosive volume and overpressure at a particular distance, describing the nature of the blast wave generated owing to a gas explosion. After calculating results with semi empirical models, CFD modelling is done to calculate overpressure generated in two cases i.e. IOCL, Jaipur scenario with trees and without trees. Simulations are performed for case of combined dispersion and explosion by giving an ignition point at specific time in a particular region. Results obtained from simulation revealed that the overpressure significantly enhanced in the presence of trees to that of without trees. Lessons learnt from this study could be employed to prevent possible causes of destruction in similar plants.