A heat exchanger includes a metal fiber structure (20) formed from metal fibers, and a housing body (for example, a pipe (10)) in which the metal fiber structure (20) is housed, and a gap is formed at least partially between the metal fiber structure (20) housed in the housing body and an inner surface of the housing body.

The present invention relates to a heat exchanger of an exhaust heat recovery apparatus having a simple structure which is configured such that exhaust gas is evenly distributed, thereby preventing a boiling phenomenon wherein coolant water is boiling, and improving efficiency of heat exchange and durability of the apparatus.

A heat exchanger having an outer tube through which a heating or cooling medium flows, a heat source that heats or cools the outer tube at a middle position at the exterior, and a heat-exchange part which can perform a heat exchange between the heating or cooling medium flows in the outer tube and the heat source; the heat-exchange part is provided with a porous body in a cylindrical shape being in close contact with an inner peripheral surface of the outer tube, at least one inside channel that is formed inside the porous body, and at least one valve that opens and closes the inside channel; and continuous pores that communicate with both ends of the flow direction of the heating or cooling medium and through which the heating or cooling medium can flow are formed.

A heat exchange structure includes: two flow channels stacked in a stacking direction (Y direction) and thermally coupled to each other; and a fin structure detachably installed in at least one flow channel of the two flow channels. The fin structure includes fins arranged in a longitudinal direction (Z direction) of the at least one flow channel in which the fin structure is installed, the fins configured to form openings alternately arranged along the at least one flow channel on one side and the other side of the at least one flow channel in the stacking direction.

A cooling channel structure includes a tubular member with openings at both ends. In an inner portion or on a surface of the tubular member, as cooling channels for flowing a cooling medium for cooling the tubular member, provided are a plurality of spiral outer surface-side channels located on an outer surface side of the tubular member, at least one inner surface-side channel located on an inner surface side of the tubular member, and a plurality of folded channels, respectively, connecting the plurality of outer surface-side channels and the at least one inner surface-side channel on one end side of the tubular member.

A cooling channel structure includes a tubular member with openings at both ends. In an inner portion or on a surface of the tubular member, as cooling channels for flowing a cooling medium for cooling the tubular member, provided are a plurality of spiral outer surface-side channels located on an outer surface side of the tubular member, at least one inner surface-side channel located on an inner surface side of the tubular member, and a plurality of folded channels, respectively, connecting the plurality of outer surface-side channels and the at least one inner surface-side channel on one end side of the tubular member.

Polymeric tube-in-shell heat exchangers with twisted tubes are provided. The heat exchanger may include one or more polymeric tube bundles, wherein each of the one or more polymeric tube bundles includes at least one tube twisted about its length or at least one pair of tubes twisted or wound around each other. The presently disclosed polymeric tube-in-shell heat exchangers with twisted tubes may be especially suited for applications where the use of polymer tubes offers advantages, such as in the case of acid solutions, food and beverage fluids, and carbon capture applications where the use of metal heat exchangers destroy the amines used for capture.

A heat exchanger includes a hollow pillar shaped honeycomb structure, a first outer cylindrical member, an inner cylindrical member, an upstream cylindrical member, a cylindrical connecting member and a downstream cylindrical member. The inner cylindrical member includes a tapered portion whose diameter is reduced from a position of a second end face of the pillar shaped honeycomb structure to the downstream end portion side. A ratio of a difference between an inner diameter of the downstream end portion of the inner cylindrical member and an inner diameter of the downstream end portion of the upstream cylindrical member to the inner diameter of the downstream end portion of the upstream cylindrical member is within ±20%.

A heat exchanger includes a hollow pillar shaped honeycomb structure, a first outer cylindrical member, an inner cylindrical member, an upstream cylindrical member, a cylindrical connecting member and a downstream cylindrical member. The inner cylindrical member includes a tapered portion whose diameter is reduced from a position of a second end face of the pillar shaped honeycomb structure to the downstream end portion side. A ratio of a difference between an inner diameter of the downstream end portion of the inner cylindrical member and an inner diameter of the downstream end portion of the upstream cylindrical member to the inner diameter of the downstream end portion of the upstream cylindrical member is within ±20%.

The present invention provides a thermal cracking tube formed with an agitating element that has a good agitation effect and improves heat transfer efficiency while minimizing an increase in the pressure loss of the fluid flowing through the cracking tube.

A thermal cracking tube 10 with an agitating element of the present invention is a thermal cracking tube having a tube axis with one end and the other end, wherein a fluid inlet is on the one end and a fluid outlet is on the other end, the tube being provided on an inner surface thereof with one or more fluid agitating elements 20 extending from the inner surface of the tube and having an inwardly facing top portion, wherein the agitating element is helically inclined to or is orthogonal to a longitudinal direction of the tube axis, and the top portion deviates to the fluid inlet side 11 or the fluid outlet side 12, relative to a center 0 of a width direction of the agitation element.