Comparative study on hot plume dispersion from ground flares in an LNG plant: FLACS vs FLUENT

Cristina Zuliani


Antonio Bennardo

LNG facilities often include large ground flares for the safe disposal of gases in the event of rare and short plant upsets. The size of such ground flares can be quite large and the amount of hot combustion gases produced is significant. Thus the dispersion of the hot plumes is critical in LNG plants due to the adverse impact of their high temperature on personnel, structures and equipment performance (e.g. air coolers), depending on the site specific wind conditions.

Purpose of this study is to compare and discuss the results obtained for a large LNG ground flare with two CFD models: a multipurpose code i.e. FLUENT (ANSYS) and a specialized tool i.e. FLACS (GexCon), developed for safety applications, mostly used for flammables dispersion and gas explosion.

The main objective of the study is to define the most appropriate set up in FLACS so as to model such phenomenon (dispersion of hot combustion gases) and to assess and discuss the differences in the results obtained with FLUENT for a real project case. The comparison is based on the iso-surface temperature profile, temperature slice profile and temperature measured at predefined targets.