Radial-flow heat exchanger with foam heat exchange fins

A radial flow heat exchanger, comprising:

• an annular-shaped core having an axial length extending from a first end to a second end, a central fluid passageway extending from the first end to the second end and defined by an interior wall of the core, and an exterior wall;
• a plate closing the central fluid passageway at either the first end or the second end and preventing fluid that is introduced into the central fluid passageway from flowing out through the first end or the second end closed by the plate;
• the annular-shaped core is formed by a plurality of heat exchange units that are connected together into an annulus, each of the heat exchange units includes:
• an extruded plate that is formed as a one piece, single unit of a single material, the extruded plate defines a plurality of integrally formed, enclosed fluid passageways through the extruded plate, the enclosed fluid passageways are formed by the one piece, single unit of a single material;
• and a plurality of discrete fins formed from graphite foam that are connected to, extend from, and are in thermal contact with a first surface of the extruded plate, each discrete fin having a flat top surface that is not directly connected to the flat top surface of an adjacent discrete fin;
• and
• for each heat exchange unit, the flat top surfaces of the discrete fins thereof are connected to and in thermal contact with a second surface of the extruded plate of an adjacent heat exchange unit;
• each plate of the plurality of heat exchange units has first and second ends, and the first and second ends of each extruded plate are friction-stir welded to the interior wall and the exterior wall, respectively, and each extruded plate defines radial fluid passageways, and the radial fluid passageways of each extruded plate are circumferentially spaced from the radial fluid passageways of the other extruded plates, and the radial fluid passageways of each extruded plate extend generally radially through the interior wall and through the exterior wall of the annular-shaped core to place the central fluid passageway in fluid communication with an exterior of the annular-shaped core;
• the fins define fluid passageways that are circumferentially spaced from one another and that extend generally axially from the first end to the second end of the core, and the generally axially extending fluid passageways and the radial fluid passageways are not closed by the plate;
• and
• the radial fluid passageways are separated from the generally axially extending fluid passageways defined by the fins so that a first fluid that flows through the generally axially extending fluid passageways defined by the fins does not mix with a second fluid that flows through the radial fluid passageways.