Lloyd’s Register Energy has released a guidance note that provides a methodology to establish risk-based cryogenic exposure based on a probabilistic approach, which is applicable to any unit where hydrocarbon and refrigerant cryogenic hazards are relevant.
The guidance describes two different methods for cryogenic risk quantification: the initial cryogenic risk analysis (ICRA) and the advanced cryogenic risk analysis (ACRA).
ICRA
The ICRA method relies on 2D models to estimate cryogenic liquid and vapour hazard zones. While this is the most common approach, it offers certain limitations as it cannot incorporate platform specifics, and thus necessitates strong conservative assumptions. The ICRA is therefore mainly suitable for cryogenic risk quantification at the early design stage.
ACRA
The ACRA risk method is based on 3D computational fluid dynamics (CFD) models and has been developed to incorporate detailed facility specifics (e.g. confinement and congestion) in the risk assessments.
Joar Dalheim, Vice President Technology in Lloyd’s Register Energy’s consulting team commented: “As natural gas is becoming increasingly important to satisfy global energy demands, so is the need for safer and more efficient facilities. Given the large quantities of cryogenic materials present on a floating LNG facility, there is a serious risk of extensive damage in the event of cryogenic failure of critical components. As the estimation methods currently available are granular, we see a need for a more inclusive approach. This is what we are delivering with our guidance note.”
Edited from press release by Angharad Lock
Read the article online at: https://www.hydrocarbonengineering.com/gas-processing/10092015/lr-safeguarding-against-the-top-safety-concern-on-flng-installations-1384/