An accidental leakage of Liquefied Natural Gas (LNG) can occur during processes of production, storage and transportation. LNG has a complex dispersion characteristic after release into the atmosphere. This complex behaviour demands a detailed description of the scientific phenomena involved in the dispersion of the released LNG. Moreover, a fugitive LNG leakage may remain undetected in complex geometry usually in semi-confined or confined areas and is prone to fire and explosion events. To identify location of potential fire and/or explosion events, resulting from accidental leakage and dispersion of LNG, a dispersion modelling of leakage is essential. This study proposes a methodology comprising of release scenarios, credible leak size, simulation, comparison of congestion level and mass of flammable vapour for modelling the dispersion of a small leakage of LNG and its vapour in a typical layout using Computational Fluid Dynamics (CFD) approach. The methodology is applied to a case study considering a small leakage of LNG in three levels of equipment congestion. The potential fire and/or explosion hazard of small leaks is assessed considering both time dependent concentration analysis and areabased model. Mass of flammable vapour is estimated in each case and effect of equipment congestion on source terms and dispersion characteristics are analysed. The result demonstrates that the small leak of LNG can create hazardous scenarios for a fire and/or explosion event. It is also revealed that higher degree of equipment congestion increases the retention time of vapour and intensifies the formation of pockets of isolated vapour cloud. This study would help in designing appropriate leak and dispersion detection systems, effective monitoring procedures and risk assessment

Item Type:	Refereed Article
Keywords:	complex layout, LNG, fugitive leakage, dispersion modelling, CFD, FLACS
Research Division:	Engineering
Research Group:	Maritime Engineering
Research Field:	Ocean Engineering
Objective Division:	Energy
Objective Group:	Energy Exploration
Objective Field:	Oil and Gas Exploration
UTAS Author:	Baalisampang, T (Mr Til Baalisampang)
UTAS Author:	Garaniya, V (Dr Vikram Garaniya)
UTAS Author:	Khan, F (Professor Faisal Khan)
ID Code:	134923
Year Published:	2019
Web of Science® Times Cited:	3
Deposited By:	NC Maritime Engineering and Hydrodynamics
Deposited On:	2019-09-13
Last Modified:	2020-03-11
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