(54g) The All Hazards Planner Tool for LNG Dispersion Modelling in Complex Environments

Liquefied Natural Gas (LNG) facilities and operations are often subject to some form of consequence analysis, as part of a quantitative risk assessment or facility siting study, to evaluate hazards and ensure the safety of workers and other personnel. One important risk associated with the storage and transportation of LNG is a potential leak scenario leading to the formation and dispersion of a resulting flammable LNG vapour cloud.

Traditional tools for predicting the dispersion of leaked substances are quick and simple to use, but may not adequately consider the effects of the built environment that includes complex urban, marine and terrain geometries. Alternatively, CFD methods have been increasing in popularity; although, their superior accuracy is met with commensurate manual effort.

The All Hazards Planner tool makes the physically accurate modelling approach of CFD more practical, easier to use and less time-consuming (both manpower and computationally). All Hazards is a fast, accurate gas dispersion modelling tool for complex environments, which employs a full-physics CFD approach but automates the intensive manual effort.

The present work demonstrates the accuracy of All Hazards using three full-scale field experiments in which LNG vapour concentrations are measured downwind of large releases. These scenarios have range of atmospheric conditions (unstable, neutral, and stable) and geometric obstacles, and they are commonly used as benchmark test cases for certification in the US for LNG gas leak modelling.