Heat exchanger and manufacturing method thereof

1. A heat exchanger comprising:

a partition wall that separates two fluids of different temperature; and

multiple plate-shaped fins formed on at least one surface of the partition wall and each having a pair of heat transfer surfaces,

wherein the partition wall and the multiple fins are made of a same metal material to constitute an integrally molded product,

the multiple fins each have a curved part and are arranged to be spaced from one another in a direction intersecting with the pair of heat transfer surfaces, and

each heat transfer surface of the pair of heat transfer surfaces is formed with multiple grooves having a depth of 100 μm to 400 μm in a thickness direction of each fin,

wherein the heat exchanger further comprises plate-shaped members each being made of another metal material having a higher emissivity than the metal material of the partition wall and the multiple fins, and attached to the partition wall between adjacent ones of the multiple fins,

wherein the partition wall constitutes a bottomed tubular body, and

the plate-shaped members are fitted into multiple mounting grooves formed on an outer surface in a bottom portion of the partition wall,

wherein the multiple fins are each connected to a bottom surface and a side circumferential surface of the bottomed tubular body that form an outer surface of the bottomed tubular body,

in a first portion of each fin connected to the bottom surface of the bottomed tubular body, the multiple grooves each extend toward the bottom surface, and

in a second portion of each fin connected to the side circumferential surface of the bottomed tubular body, the multiple grooves each extend substantially vertically.

2. The heat exchanger according to claim 1 , wherein another surface of the partition wall that is not provided with the fins is formed with multiple pores each having a diameter of 10 nm to 30 nm.

3. The heat exchanger according to claim 1 , further comprising a shell which is provided to cover outer sides of the multiple fins and to which outer edge portions of the multiple fins opposite from the partition wall are each connected.

4. The heat exchanger according to claim 1 , further comprising multiple pin-shaped fins provided to protrude outward on a region of the bottom surface of the bottomed tubular body where the multiple fins are not formed.

5. The heat exchanger according to claim 1 , wherein the curved part of each of the multiple fins is curved helically.

6. The heat exchanger according to claim 1 , wherein each fin has a cross section tapering in a direction away from the partition wall.