Abstract: A flow-path structure through which fluid flows includes: a barrel body through which fluid flows in an inner circumference; and a frame body configured to connect a flow path member, the flow path member being configured to guide the fluid into the barrel body, wherein the frame body has: a ring-shaped frame part configured to be fitted into an outer surface of the barrel body; and an inner engagement portion configured to engage with an inner surface of the barrel body so as to hold a state in which the outer surface of the barrel body is brought into contact with the frame part.

Abstract: A flow-path structure through which fluid flows includes: a barrel body through which fluid flows in an inner circumference; and a frame body configured to connect a flow path member, the flow path member being configured to guide the fluid into the barrel body, wherein the frame body has: a ring-shaped frame part configured to be fitted into an outer surface of the barrel body; and an inner engagement portion configured to engage with an inner surface of the barrel body so as to hold a state in which the outer surface of the barrel body is brought into contact with the frame part.

Abstract: A heat exchanger tube which, while preventing the increased flow resistance when the medium flows, can enhance the heat radiation performance, is provided. The heat exchanger tube 1 includes an upstream side linear flow path part 4A and a downstream side linear flow path part 4B connecting an entrance part 2 and exist part 3 to each other and enabling the medium to flow therethrough, wherein at least one of the upstream side flow path part 4A and downstream side flow path part 4B includes, within the flow path of the medium, wave-shaped portions 5a, 5b, 5c, 5d extending in the longitudinal direction of the tube and continuing with each other for guiding the medium.