Abstract: The marine re-liquefaction system is to use different refrigeration methods to generate cold energy and re-liquefy BOG to maintain normal cabin pressure. Compared with onshore BOG re-liquefaction equipment,marine BOG re-liquefaction equipment has higher requirements for equipment compactness,safety and maintainability. At present,its core technology is mainly mastered by foreign equipment manufacturers. The selection of marine BOG re-liquefaction process,the technical characteristics,development history,component technology and relevant patents of the mainstream devices are reviewed and summarized,and the necessity of localization is proposed.

Key words: BOG, re-liquefaction, technological development