Disclosed herein is a BOG reliquefaction system for LNG vessels. The BOG reliquefaction system includes a compressor compressing BOG, a heat exchanger cooling the compressed BOG by exchanging heat between the compressed BOG and BOG used as a refrigerant, and an expansion unit for expanding the BOG having been cooled by the heat exchanger, wherein the heat exchanger includes a core, in which heat exchange between a hot fluid and a cold fluid occurs, the core including a plurality of diffusion blocks, and a fluid diffusion member diffusing a fluid introduced into the core or a fluid discharged from the core.

The heat exchanger is generally ring-shaped and includes a plurality of heat exchange modules (2), which are mutually independent, being distributed about the axis (A1) of the ring. The modules (2) are assembled with one another, being successively spaced apart in pairs, a space (E1) being created between two adjacent modules (2). At least one of the spaces (E1) receives at least one conductive heat-transfer element (7) extending between respective walls of at least two adjacent the modules (2) which are oriented facing one another.

A heat exchanger includes a base and a plurality of substantially parallel and substantially vertical walls spaced apart and integrally formed with the base via additive manufacturing. The heat exchanger also includes at least one parting sheet not integrally formed with the plurality of walls, but being attached to the plurality of walls, defining flow channels between the walls, the base, and the at least one parting sheet.

An additively manufactured heat exchanger configured to transfer heat between a first fluid and a second fluid includes a first channel with a first wall configured to port flow of a first fluid and a second channel with a second wall configured to port flow of a second fluid. The heat exchanger also includes a barrier channel containing unprocessed build powder provided by the additive manufacturing process and is located between the first wall and the second wall. The barrier channel is configured to prevent mixing of the first fluid and the second fluid when one of the first wall and the second wall ruptures.

A method of forming fluid flow channels for a heat exchanger core includes additively manufacturing the channels such that each channel includes a straight axial fluid path portion (A) extending from one end of the channel to the other and that the cross-sectional shape of the channel varies along its length to form curved contact surfaces for the fluid as it flows along the channel, while keeping the cross-sectional area constant along each channel.

A cyclone cooler device includes a housing that defines an interior channel elongated along a center axis. One or more of the fluid passage or configuration of an inlet end of the channel is shaped to induce a swirling flow of a cooling fluid within the channel while the channel is thermally coupled with one or more heat sources. The swirling flow of the cooling fluid removes thermal energy from and cools the one or more heat sources. During the swirling flow, the cooling fluid rotates around the center axis of the channel while also moving along the length of the center axis. The cooling fluid changes phases during the swirling flow to cool the heat source(s).

A heat exchange structure includes a primary heat exchange body with a first fluid channel fluidly separated from a second fluid channel by a barrier channel, an inlet manifold in fluid communication with the first fluid channel, and a secondary heat exchange body. The secondary heat exchange body is in fluid communication with the barrier channel, is arranged within the inlet manifold, and fluidly couples the barrier channel to the external environment. Fluid systems and heat exchange methods are also described.

A heat exchange structure includes a primary heat exchange body with a first fluid channel fluidly separated from a second fluid channel by a barrier channel, an inlet manifold in fluid communication with the first fluid channel, and a secondary heat exchange body. The secondary heat exchange body is in fluid communication with the barrier channel, is arranged within the inlet manifold, and fluidly couples the barrier channel to the external environment. Fluid systems and heat exchange methods are also described.

A multilayered material system includes at least one of a liner sheet and a cellular core, and a multilayered composite joined to the at least one of a liner sheet and a cellular core. The multilayered composite includes hollow microspheres dispersed within a metallic matrix material.

In a header of a heat exchanger core, a header passage includes: at least one radial passage extending along a radial direction, and a plurality of circumferential passages branched from each radial passage and communicating with one or more of the axial passages, respectively. The flow passage area of each radial passage is smaller in a second position than in a first position, where the second position is inward of the first position in the radial direction.