This application discloses a new type of suction leg, an offshore caisson, a sit-on-bottom supporting platform. The suction leg includes a sealing long pile, this sealing long pile including a tubular pipe and a top head connected tightly to the tubular pipe to form cylindrical integral structure with sealing top and opening bottom. The top head has at least one opening to be able to open or close. The sealing long pile can be penetrated into the seabed by a gravity penetration method or/and a suction pile penetration method, or pulled out from the seabed by a buoyancy uplift method or/and a suction pile uplift method.

A steel plate and concrete composite tank unit, tank groups and offshore platforms with new type of tank units are disclosed. The tank unit comprises an outer concrete tank that comprises an outer tank shell, two heads and ring shell connections at both ends, an inner steel tank that comprises an inner tank shell, epitaxial structures at both ends of the inner steel tank. Inner tank shell is connected to the outer tank shell by epitaxial structures, and an isolation layer that is formed from the gap between the outer concrete tank and the inner steel tank where it is filled with isolation medium.

A system for storing and transporting compressed natural gas includes source and destination facilities and a vehicle, each of which includes pressure vessels. The pressure vessels and gas therein may be maintained in a cold state by a carbon-dioxide-based refrigeration unit. Hydraulic fluid (and/or nitrogen) ballast may be used to fill the pressure vessels as the pressure vessels are emptied so as to maintain the pressure vessels in a substantially isobaric state that reduces vessel fatigue and lengthens vessel life. The pressure vessels may be hybrid vessels with carbon fiber and fiber glass wrappings. Dip tubes may extend into the pressure vessels to selectively expel/inject gas from/into the top of the vessels or hydraulic fluid from/into the bottom of the vessels. Impingement deflectors are disposed adjacent to the dip tubes inside the vessels to discourage fluid-induced erosion of vessel walls.

A heat exchange system includes cooling tubes that carry coolant and are placed on an external surface of a storage tank, which may be spherical, cylindrical, or other shape. The storage tank may be a cryogenic rocket fuel tank. The cooling tubes are bent to particular radius of curvatures that correspond to the varying curvatures of the storage tank. A network of spacers and bridge brackets with adjustable setscrews are used to precisely place the cooling tubes in correct positions on the external surface of the storage tank. Once placed in the desired position, the setscrews are adjusted to maximize the surface area contact between the cooling tubes and the exterior surface of the storage tank, resulting in optimal heat transfer without overstressing the materials of the tubing or the storage tank. The precisely positioned tubes may then be permanently affixed to the exterior surface of the storage tank using a cryogenic adhesive.

A heat exchange system includes cooling tubes that carry coolant and are placed on an external surface of a storage tank, which may be spherical, cylindrical, or other shape. The storage tank may be a cryogenic rocket fuel tank. The cooling tubes are bent to particular radius of curvatures that correspond to the varying curvatures of the storage tank. A network of spacers and bridge brackets with adjustable setscrews are used to precisely place the cooling tubes in correct positions on the external surface of the storage tank. Once placed in the desired position, the setscrews are adjusted to maximize the surface area contact between the cooling tubes and the exterior surface of the storage tank, resulting in optimal heat transfer without overstressing the materials of the tubing or the storage tank. The precisely positioned tubes may then be permanently affixed to the exterior surface of the storage tank using a cryogenic adhesive.