Comparative safety assessment of LNG re-liquefaction systems applied on LNG carriers

Nikolaos Kapellas, Byongug Jeong

Research output: Contribution to journalArticlepeer-review

18 Downloads (Pure)


This research was aimed to evaluate the safety of the LNG cargo compressor room against unwanted gas leakage from two different re-liquefaction systems applicable for an LNG carrier: 1) the Partial (Full) Re-liquefaction System (P(F)RS) and 2) the combination of Partial Re-liquefaction System and Mixed Refrigerant Re-liquefaction system (PRS+MRS). To achieve this goal, quantitative risk assessment was carried out with the integration of system hierarchical modelling, statistical analysis, and CFD simulation. The frequency of initial leakages, occurring to each component of the re-liquefaction systems, was analysed, whereas for the consequence analysis, a CFD program of PyroSim was employed to simulate the gas dispersion in the confined room fitted with mechanical ventilation systems. In addition, various ventilation capacities were investigated with changes in their allocations in the room in order to determine these parametric influences on the results. The risk level of re-liquefaction systems was determined in a quantitative way. Research results clearly presented the importance of the proper arrangement of the ventilation systems. The risk levels were estimated at 5.6 E-3/year for P(F)RS whereas about 9.6 E-3/year for the PRS+MRS in consideration of current regulations. However, the increase in the ventilation capacity was found to reduce the risk levels. The research findings are highly believed to offer meaningful guidance into future safety regulatory frameworks.
Original languageEnglish
Pages (from-to)185-198
Number of pages14
JournalJournal of International Maritime Safety, Environmental Affairs, and Shipping
Issue number4
Early online date22 Nov 2022
Publication statusPublished - 30 Nov 2022


  • LNG re-liquefaction system
  • PRS
  • MRS
  • LNG carrier with re-liquefaction system
  • gas dispersion


Dive into the research topics of 'Comparative safety assessment of LNG re-liquefaction systems applied on LNG carriers'. Together they form a unique fingerprint.

Cite this