A radiant tube includes a conduit; and one or more heat transfer promoters disposed in the conduit, wherein the heat transfer promoter includes a body part on a center side of the conduit, and protruding parts protruding from the body part toward an inner wall surface of the conduit, the protruding parts are on an outer periphery of the body part to be arranged in a circumferential direction of the conduit, the protruding parts includes first protruding parts having a distal end portion facing the inner wall surface across a gap ΔL, and a second protruding part, the number of first protruding parts is greater than the number of second protruding parts, and a ratio (ΔL/Dt) of the gap ΔL to an equivalent diameter Dt of a conduit portion is x %, where the heat transfer promoter is disposed, and formula (1) is satisfied: 0.3%<x<7%.

A radiant tube includes a conduit; and one or more heat transfer promoters disposed in the conduit, wherein the heat transfer promoter includes a body part on a center side of the conduit, and protruding parts protruding from the body part toward an inner wall surface of the conduit, the protruding parts are on an outer periphery of the body part to be arranged in a circumferential direction of the conduit, the protruding parts includes first protruding parts having a distal end portion facing the inner wall surface across a gap ΔL, and a second protruding part, the number of first protruding parts is greater than the number of second protruding parts, and a ratio (ΔL/Dt) of the gap ΔL to an equivalent diameter Dt of a conduit portion is x %, where the heat transfer promoter is disposed, and formula (1) is satisfied: 0.3%<x<7%.

Stacked cooling assemblies and combustor bead ends are provided. A stacked cooling assembly includes an inlet plate defining an inlet to a coolant circuit, an outlet plate defining an outlet of the coolant circuit, and an intermediate plate disposed between the inlet plate and die outlet plate. The intermediate plate defines an intermediate cavity. A downstream surface of the inlet plate, an upstream surface of the outlet plate, and the intermediate cavity collectively define a connecting channel that fluidly couples the inlet to the outlet.

Stacked cooling assemblies and combustor bead ends are provided. A stacked cooling assembly includes an inlet plate defining an inlet to a coolant circuit, an outlet plate defining an outlet of the coolant circuit, and an intermediate plate disposed between the inlet plate and die outlet plate. The intermediate plate defines an intermediate cavity. A downstream surface of the inlet plate, an upstream surface of the outlet plate, and the intermediate cavity collectively define a connecting channel that fluidly couples the inlet to the outlet.

To cool a cooling target with liquid, a cooling apparatus includes a cooling medium holding portion configured to support the cooling target and hold a flow passage of the cooling medium, and a device configured to drive the cooling medium. The section where the cooling medium comes into contact with the cooling target in the flow passage of the cooling medium holding portion, the section where the cooling medium flows in, and the section where the cooling medium flows out have different flow passage structures so that the cooling medium passes at high speed while in contact with a cooling surface of the cooling target to achieve high cooling efficiency.

To cool a cooling target with liquid, a cooling apparatus includes a cooling medium holding portion configured to support the cooling target and hold a flow passage of the cooling medium, and a device configured to drive the cooling medium. The section where the cooling medium comes into contact with the cooling target in the flow passage of the cooling medium holding portion, the section where the cooling medium flows in, and the section where the cooling medium flows out have different flow passage structures so that the cooling medium passes at high speed while in contact with a cooling surface of the cooling target to achieve high cooling efficiency.

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.

A heat exchanger (4) has fluid flow channels (6) with at least one heat exchanging surface (10) which has an undulating surface section for which the surface profile varies along a predetermined direction such that at a first edge (E1) the surface profile follows a first transverse wave (20), at a second edge (E)2 the surface profile follows a second transverse wave (22) and at an intermediate point I between the edges the surface profile follows a third transverse wave (24). The third transverse wave (24) has a different phase, frequency or amplitude to the first and second transverse waves so that chevron-shaped ridges and valleys are formed. This improves the mixing of fluid passing through the channel and hence the heat exchange efficiency.

A heat exchanger (4) has fluid flow channels (6) with at least one heat exchanging surface (10) which has an undulating surface section for which the surface profile varies along a predetermined direction such that at a first edge (E1) the surface profile follows a first transverse wave (20), at a second edge (E)2 the surface profile follows a second transverse wave (22) and at an intermediate point I between the edges the surface profile follows a third transverse wave (24). The third transverse wave (24) has a different phase, frequency or amplitude to the first and second transverse waves so that chevron-shaped ridges and valleys are formed. This improves the mixing of fluid passing through the channel and hence the heat exchange efficiency.

The purpose of the present invention is to provide a plate-type heat exchanger in which the formation of burrs and chips during fin processing may be eliminated by eliminating fin processing work for stacking and bonding fins and plates. In order to achieve the above purpose, a plate-type heat exchanger according to the present invention is characterized by comprising: plates which include an inlet formed on one side in the longitudinal direction, an outlet formed on the other side in the longitudinal direction, and a flow surface formed between the inlet and the outlet; and a fin part which is inserted into a plate part formed by bonding a pair of the plates and rests on the flow surface. The plates include a fin part movement preventing means to ensure that one end of the fin part in the longitudinal direction is spaced a certain distance from the inlet and the other end of the fin part in the longitudinal direction is spaced a certain distance from the outlet such that the fin part rests only on the flow surface.