A vacuum heat-insulating material includes: an outer cover material; and a core material which is sealed in a tightly closed and decompressed state on the inside of the outer cover material. Outer cover material has gas barrier properties and satisfies at least one of a condition that a linear expansion coefficient is 80×10.sup.−5/° C. or lower when a static load is 0.05 N within a temperature range of −130° C. to 80° C., inclusive, a condition that an average value of a linear expansion coefficient is 65×10.sup.−5/° C. or higher when a static load is 0.4 N within a temperature range of −140° C. to −130° C., inclusive, a condition that an average value of a linear expansion coefficient is 20×10.sup.−5/° C. or higher when a static load is 0.4 N within a temperature range of −140° C. to −110° C., inclusive, and a condition that an average value of a linear expansion coefficient is 13×10.sup.−5/° C. or higher when a static load is 0.4 N within a temperature range of +50° C. to +65° C., inclusive.

A corner structure comprises: a fixed member fixed to a corner of a storage tank; a movable member supported on the fixed member so as to be linearly movable; a stop member attached to the fixed member to prevent the movable member from being detached from the fixed member; and a heat insulating member disposed between a sealing wall and a hull. The fixed member comprises a guide portion provided with a guide recessed portion, the movable member comprises a guide protruding portion inserted into the guide recessed portion, and the width and the length of the guide protruding portion are smaller than the width and the length of the guide recessed portion, so that the movable member can be supported on the fixed member to be movable in the longitudinal direction and in the direction perpendicular to the longitudinal direction.

A corner structure comprises: a fixed member fixed to a corner of a storage tank; a movable member supported on the fixed member so as to be linearly movable; a stop member attached to the fixed member to prevent the movable member from being detached from the fixed member; and a heat insulating member disposed between a sealing wall and a hull. The fixed member comprises a guide portion provided with a guide recessed portion, the movable member comprises a guide protruding portion inserted into the guide recessed portion, and the width and the length of the guide protruding portion are smaller than the width and the length of the guide recessed portion, so that the movable member can be supported on the fixed member to be movable in the longitudinal direction and in the direction perpendicular to the longitudinal direction.

Disclosed is a heat-insulation system for a liquefied natural gas cargo hold, which comprises a primary sealing wall, a secondary sealing wall, and a secondary heat-insulating layer, and is applied to a liquefied natural gas cargo hold. The heat-insulation system for a liquefied natural gas cargo hold comprises a collar stud installed on a line on the upper surface of the secondary heat-insulating layer where an anchor strip is installed.

Disclosed is a heat-insulation system for a liquefied natural gas cargo hold, which comprises a primary sealing wall, a secondary sealing wall, and a secondary heat-insulating layer, and is applied to a liquefied natural gas cargo hold. The heat-insulation system for a liquefied natural gas cargo hold comprises a collar stud installed on a line on the upper surface of the secondary heat-insulating layer where an anchor strip is installed.

A double-shell tank includes: an inner shell storing liquefied gas; an outer shell surrounding the inner shell, the outer shell forming a vacuum space between the inner shell and the outer shell; at least one metal sheet mounted to the inner shell, such that the metal sheet faces at least a bottom surface of the inner shell; an adsorbent placed on the metal sheet, the adsorbent adsorbing gas molecules by physisorption; and a thermal insulator covering the inner shell over the metal sheet.

A double-shell tank includes: an inner shell storing liquefied gas; an outer shell surrounding the inner shell, the outer shell forming a vacuum space between the inner shell and the outer shell; at least one metal sheet mounted to the inner shell, such that the metal sheet faces at least a bottom surface of the inner shell; an adsorbent placed on the metal sheet, the adsorbent adsorbing gas molecules by physisorption; and a thermal insulator covering the inner shell over the metal sheet.

A transport container for helium, with an inner container for receiving the helium, a coolant container for receiving a cryogenic liquid (N.sub.2), an outer container, in which the inner container and the coolant container are contained, a thermal shield, in which the inner container is contained and which can be actively cooled with the aid of a liquid phase of the cryogenic liquid (LN.sub.2), the thermal shield having at least one first cooling line, in which the liquid phase of the cryogenic liquid can be received for actively cooling the thermal shield, and an insulating element, which is arranged between the outer container and the thermal shield and which can be actively cooled with the aid of a gaseous phase of the cryogenic liquid (GN.sub.2), the insulating element having at least one second cooling line, in which the gaseous phase of the cryogenic liquid can be received.

A transport container for helium, with an inner container for receiving the helium, a coolant container for receiving a cryogenic liquid (N.sub.2), an outer container, in which the inner container and the coolant container are contained, a thermal shield, in which the inner container is contained and which can be actively cooled with the aid of a liquid phase of the cryogenic liquid (LN.sub.2), the thermal shield having at least one first cooling line, in which the liquid phase of the cryogenic liquid can be received for actively cooling the thermal shield, and an insulating element, which is arranged between the outer container and the thermal shield and which can be actively cooled with the aid of a gaseous phase of the cryogenic liquid (GN.sub.2), the insulating element having at least one second cooling line, in which the gaseous phase of the cryogenic liquid can be received.

The present disclosure relates to a vacuum heat-insulation device for a large low-temperature tank, the vacuum heat-insulation device having excellent heat insulation properties and vacuum stability by using a low-temperature heat-insulating material maintained in a vacuum at all times so as to store an ultra-low-temperature liquefied gas such as liquid nitrogen (LN.sub.2) or liquid hydrogen (LH.sub.2), and to a vacuum heat-insulation device for a low-temperature tank, the vacuum heat-insulation device having a flexible structure in which a vacuum jacket is partially contractible according to contraction of a low-temperature tank or a low-temperature heat-insulating layer.