This presentation is a part of the 2022 FLACS User Group (FLUG) Meeting. Fill in the form below to access the recording and dive into the valuable insights shared by industry experts.
About the presentation
Every LNG project that is proposed to be built, expanded or significantly modified needs to meet the siting requirements of the applicable regulations, which aim at ensuring the safety of the public and public property in the event of accidents within the LNG plant.
In order to quantify the hazard footprints for potential accident scenarios (such as flammable vapour dispersion, pool and jet fires, vapour cloud explosions, etc.), computational tools must be used. Given the multiplicity of modelling tools available to perform siting studies, regulators are often faced with potentially conflicting results and need to be able to understand which results they can trust. For this reason, a Model Evaluation Protocol (MEP) was developed in 2007 to allow computational tools for vapour dispersion modelling to be reviewed. This protocol was then successfully applied to two software packages (Phast and FLACS-CFD), which were found acceptable for LNG vapour dispersion modelling under US federal regulations.
The 2007 MEP, however, is very limited in scope: in fact, it only addresses vapour dispersion modelling and, more specifically, only from atmospheric releases (e.g., vapours from a liquid spill onto the ground). This means that there are currently no established protocols to evaluate models to simulate hazards such as the flammable or toxic dispersion of a vapour cloud from a pressurized release (e.g., a pipe breach), the overpressures generated by a vapour cloud explosion, etc.
Blue Engineering and Consulting and the Gas Technology Institute are collaborating on a DOT-PHMSA-sponsored research project to develop a new set of Model Evaluation Protocols, that will allow the review of modelling tools for each of the above-referenced hazards. The new MEPs will greatly increase the confidence of authorities as well as the public, by defining which models may be used and under which limitations, and what validation factors need to be applied depending on the type of hazards being evaluated.
As of now, MEPs have been completed for flammable and toxic dispersion, and the MEP for source term models is nearing completion. The presentation will provide a summary of the completed MEPs and an outlook towards the remaining work.
About the speaker
Dr Filippo Gavelli, P.E.
Consultant @ Blue Engineering and Consulting Company
Dr Filippo Gavelli is a Consultant with Blue Engineering and Consulting, where he focuses on hazard analyses and risk assessments for LNG facilities. He has over 25 years of experience with CFD modelling, including vapour cloud dispersion, pool and jet fires, and vapour cloud explosions.
Dr Gavelli was previously the Head of Dispersion Consulting at Gexcon US and was closely involved with the FLACS model validation effort for the U.S. Department of Transportation. He has been a member of the NFPA 59A committee for 15 years and has published several papers on the modelling of gas dispersion and vapour cloud explosions using FLACS.
