US 12,247,706 B2
Boil-off gas reliquefaction system
Jae Hyeoung Jang, Incheon (KR); Sung Kak Lyu, Seoul (KR); Jin Yeol Yu, Geoje-si (KR); and Won Jae Choi, Seoul (KR)
Assigned to HANWHA OCEAN CO., LTD., Gyeongsangnam-Do (KR)
Filed by DAEWOO SHIPBUILDING & MARINE ENGINEERING CO., LTD., Geoje-si (KR)
Filed on Sep. 8, 2022, as Appl. No. 17/940,482.
Application 17/940,482 is a division of application No. 16/615,748, previously published as PCT/KR2017/008375, filed on Aug. 3, 2017.
Claims priority of application No. 10-2017-0097318 (KR), filed on Jul. 31, 2017.
Prior Publication US 2023/0019057 A1, Jan. 19, 2023
Int. Cl. F25J 1/00 (2006.01); B63H 21/38 (2006.01); F17C 6/00 (2006.01); F17C 9/02 (2006.01); F17C 13/00 (2006.01)
CPC F17C 9/02 (2013.01) [B63H 21/38 (2013.01); F17C 6/00 (2013.01); F17C 13/004 (2013.01); F25J 1/0025 (2013.01); F25J 1/004 (2013.01); F17C 2221/033 (2013.01); F17C 2227/0339 (2013.01); F17C 2265/017 (2013.01); F17C 2265/033 (2013.01); F17C 2265/037 (2013.01); F17C 2265/038 (2013.01); F25J 2210/90 (2013.01); F25J 2230/60 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A boil-off gas (BOG) reliquefaction system comprising:
a compressor configured to compress BOG from a storage tank to provide compressed BOG (CBOG);
a heat exchanger configured to cool a flow of the CBOG from the compressor through heat exchange using the BOG from the storage tank;
a pressure reducer disposed downstream of the heat exchanger and configured to liquefy at least part of the flow of the CBOG from the heat exchanger to provide a flow of gas-liquid mixture, wherein the compressor is configured to use lubricant oil, at least part of which is contained in the flow of the CBOG and the flow of the gas-liquid mixture;
a gas/liquid separator disposed downstream of the pressure reducer and configured to separate the gas-liquid mixture discharged from the pressure reducer into liquefied gas generated through reliquefaction and gaseous BOG; and
an oil filter disposed downstream of the pressure reducer and comprising a mesh configured to screen at least part of the lubricant oil in the gaseous BOG from the gas/liquid separator,
wherein the oil filter is disposed on a sixth supply line through which the gaseous BOG separated by the gas/liquid separator is discharged,
wherein the oil filter comprises:
an oil filter body having a bottom end, a top end, and the mesh between the bottom end and the top end, wherein the oil filter body defines a longitudinal central axis extending from the bottom end to the top end;
an inlet port disposed at a lower portion of the oil filter body, wherein the gaseous BOG from the gas/liquid separator enters into the oil filter body through the inlet port; and
an outlet port disposed at an upper portion of the oil filter body, wherein the gaseous BOG that passes through the mesh exits out of the oil filter body through the outlet port,
wherein the inlet port is spaced apart from the bottom end of the oil filter body,
wherein the outlet port is spaced apart from the top end of the oil filter body,
wherein the mesh includes a bottom end and a top end,
wherein the oil filter body defines a virtual line perpendicular to the longitudinal central axis and passing through the bottom end of the oil filter body,
wherein a shortest distance between the virtual line and the bottom end of the mesh is greater than a shortest distance between the virtual line and the inlet port,
wherein a shortest distance between the virtual line and the outlet port is greater than a shortest distance between the virtual line and the top end of the mesh.