Disclosed is a marine vessel to transport natural gas hydrates (NGH), the marine vessel includes a hull formed from solid NGH and a skeletal structure to support the hull. Additionally disclosed is a container to transport NGH including a block of solid NGH and a skeletal structure to support the block. Further disclosed is a method of fabricating a marine vessel for transporting and storing natural gas hydrates (NGH), the method includes preparing a mold, placing a skin layer in the mold, assembling a skeletal structure in the mold, preparing a NGH slurry, and pouring into NGH slurry into the mold.

Disclosed is a marine vessel to transport natural gas hydrates (NGH), the marine vessel includes a hull formed from solid NGH and a skeletal structure to support the hull. Additionally disclosed is a container to transport NGH including a block of solid NGH and a skeletal structure to support the block. Further disclosed is a method of fabricating a marine vessel for transporting and storing natural gas hydrates (NGH), the method includes preparing a mold, placing a skin layer in the mold, assembling a skeletal structure in the mold, preparing a NGH slurry, and pouring into NGH slurry into the mold.

The present disclosure relates to a liquefied gas storage tank and a ship including the same. A liquefied gas storage tank according to the present disclosure is a liquefied gas storage tank for storing a cryogenic material and includes a primary barrier made of metal to form an accommodating space for accommodating a cryogenic material; a primary insulating wall in which a primary plywood and a primary insulating material are sequentially disposed to the outside of the primary barrier; a secondary barrier provided on the outside of the primary insulating wall; and a secondary insulating wall in which a secondary insulating material and a secondary plywood are sequentially disposed in a stack to the outside of the secondary barrier, wherein the secondary barrier includes a main barrier provided on top of each secondary insulating wall constituting a unit element; and an auxiliary barrier connecting the adjacent main barriers to each other, the secondary barrier is formed of a mixed material of a metal and a non-metal, and the primary insulating wall has a thickness of 66% to 166% of that of the secondary insulating wall in order to lower a thermal stress.

The present disclosure relates to a liquefied gas storage tank and a ship including the same. A liquefied gas storage tank according to the present disclosure is a liquefied gas storage tank for storing a cryogenic material and includes a primary barrier made of metal to form an accommodating space for accommodating a cryogenic material; a primary insulating wall in which a primary plywood and a primary insulating material are sequentially disposed to the outside of the primary barrier; a secondary barrier provided on the outside of the primary insulating wall; and a secondary insulating wall in which a secondary insulating material and a secondary plywood are sequentially disposed in a stack to the outside of the secondary barrier, wherein the secondary barrier includes a main barrier provided on top of each secondary insulating wall constituting a unit element; and an auxiliary barrier connecting the adjacent main barriers to each other, the secondary barrier is formed of a mixed material of a metal and a non-metal, and the primary insulating wall has a thickness of 66% to 166% of that of the secondary insulating wall in order to lower a thermal stress.

A liquefied gas storage tank of the present disclosure includes: a flat block including a flat primary insulating wall disposed on a flat portion on a first surface or a second surface at different angles forming a storage space for accommodating liquefied gas, the flat primary insulating wall securing a flat primary barrier made of metal and being disposed on the outside of the flat primary barrier, a flat secondary barrier disposed on the outside of the flat primary insulating wall, and a flat secondary insulating wall disposed on the outside of the flat secondary barrier; and a corner block including a corner primary insulating wall disposed in a corner portion where the first surface and the second surface meet, the corner primary insulating wall securing a corner primary barrier made of metal and being disposed on the outside of the corner primary barrier, a corner secondary barrier disposed on the outside of the corner primary insulating wall, and a corner secondary insulating wall disposed on the outside of the corner secondary barrier, wherein the corner primary insulating wall includes an outer primary plywood secured to the corner secondary barrier, an inner primary plywood to which the corner primary barrier is secured, and a corner primary insulation material disposed between the inner primary plywood and the outer primary plywood.

A liquefied gas storage tank of the present disclosure includes: a flat block including a flat primary insulating wall disposed on a flat portion on a first surface or a second surface at different angles forming a storage space for accommodating liquefied gas, the flat primary insulating wall securing a flat primary barrier made of metal and being disposed on the outside of the flat primary barrier, a flat secondary barrier disposed on the outside of the flat primary insulating wall, and a flat secondary insulating wall disposed on the outside of the flat secondary barrier; and a corner block including a corner primary insulating wall disposed in a corner portion where the first surface and the second surface meet, the corner primary insulating wall securing a corner primary barrier made of metal and being disposed on the outside of the corner primary barrier, a corner secondary barrier disposed on the outside of the corner primary insulating wall, and a corner secondary insulating wall disposed on the outside of the corner secondary barrier, wherein the corner primary insulating wall includes an outer primary plywood secured to the corner secondary barrier, an inner primary plywood to which the corner primary barrier is secured, and a corner primary insulation material disposed between the inner primary plywood and the outer primary plywood.

A membrane finishing sheet, which is disposed at a membrane finishing part among multiple membrane sheets which form a sealing wall installed at a membrane type cargo, comprises a corrugated part having a structure closed in a direction toward the membrane finishing part. In addition, a membrane insulation structure comprising a membrane finishing sheet according to the present invention comprises a membrane finishing sheet disposed at a membrane finishing part among multiple membrane sheets which form a sealing wall installed at a membrane type cargo. Among four sides of the membrane finishing sheet, a finishing side in contact with the membrane finishing part has a structure in which the corrugated part is closed and thus provides a membrane insulation structure that does not require a separate finishing member for sealing a membrane.

A membrane finishing sheet, which is disposed at a membrane finishing part among multiple membrane sheets which form a sealing wall installed at a membrane type cargo, comprises a corrugated part having a structure closed in a direction toward the membrane finishing part. In addition, a membrane insulation structure comprising a membrane finishing sheet according to the present invention comprises a membrane finishing sheet disposed at a membrane finishing part among multiple membrane sheets which form a sealing wall installed at a membrane type cargo. Among four sides of the membrane finishing sheet, a finishing side in contact with the membrane finishing part has a structure in which the corrugated part is closed and thus provides a membrane insulation structure that does not require a separate finishing member for sealing a membrane.

Disclosed is a BOG reliquefaction system. The BOG reliquefaction system includes: a compressor compressing BOG; a heat exchanger cooling the BOG compressed by the compressor through heat exchange using BOG not compressed by the compressor as a refrigerant; a pressure reducer disposed downstream of the heat exchanger and reducing a pressure of fluid cooled by the heat exchanger; and a second oil filter disposed downstream of the pressure reducer, wherein the compressor includes at least one oil-lubrication type cylinder and the second oil filter is a cryogenic oil filter.

Disclosed is a corner structure of a liquefied gas storage tank, wherein the corner structure is installed at a corner of the storage tank for storing liquefied gas to support sealing walls. The corner structure includes: a stationary member secured to an inner surface of a hull structure wall; a movable member disposed on the stationary member such that the sealing walls are joined thereto; and an insulating member interposed between the sealing walls and the hull structure wall. The stationary member includes a stationary member body bent at a curved portion thereof in an opposite direction to the movable member, and the movable member includes a movable member body bent at a bent portion thereof in an opposite direction to the stationary member. The stationary member and the movable member are coupled to each other by a fastening member that penetrates the curved portion and the bent portion.