Home > Products > Oil and Gas Systems > Marine Gas Process Systems   1) LNG Re-liquefaction System For the ships powered by low-speed diesel engines, cargo boiloff gas (called BOG) needs to be reliquefied onboard and returned to the tanks. In the LNG re-liquefaction system, the boiloff gas generated due to heat ingress into the cargo tanks first goes through the BOG to BOG Heat Exchanger and becomes warm ambient-pressured BOG. Then, it goes through the compressors and aftercoolers for being compressed and cooled. The BOG stream is further cooled down by N₂refrigeration cycle and becomes LNG at Cryogenic Heat Exchanger. Finally, LNG returns to the LNG cargo tanks. For N₂refrigeration cycle, the ambient-temperature N₂first gets compressed by N₂compressor and cooled down by aftercooler. Then, it goes through N₂Heat Exchanger to be further cooled down. Through the N₂expander, the N₂stream becomes the cryogenic low pressure N₂. This cryogenic conditioned N₂finally goes through the Cryogenic Heat Exchanger to make BOG be re-liquefied. Since June 2005, Shinyoung has participated in the R&D project, called "Ko-Reli (Korean BOG Re-liquefaction system development project)" in collaboration with the Korea Institute of Science and Technology (KIST), Korea Gas Corporation (KOGAS), and three major Korean shipbuilders - Hyundai Heavy Industries (HHI), Samsung Heavy Industries (SHI) and Daewoo Shipbuilding & Marine Engineering (DSME). Since then, Shinyoung has taken a main role as a project leader. Currently, in this R&D project, DewMax™ has been developed and dubbed to the market. At this stage, all the system design and theoretical evaluation for this DewMaxTM has been completed and the pilot plant (1/5 scale) is being built at the Incheon KOGAS LNG import terminal to verify the capabilities and safety performance.     2) LPG Re-liquefaction System The LPG re-liquefaction system re-liquefies the BOG and returns to the cargo tanks. The BOG from the cargo tanks first gets to the Knock Out Drum to be separated from LPG. Then, the BOG stream goes through gas compressors to be pre-cooled down. Next, the BOG stream gets furhter cooled down at the heat exchanger and gets re-liquefied by expanders. Finally, LPG goes back to the cargo tanks. The RV vaporizer is normally installed in LNG or LPG-RV (Regasification Vessel). It is used for vaporizing LNG or LPG in order to transport the gas to lands when the vessel gets to the destination. Shinyoung Heavy Industries Co., Ltd. Tel: +82-2-785-9599 / Fax: +82-2-785-9590 E-mail: sasong@syhico.com