Heat exchange core, heat exchanger, and method for manufacturing heat exchange core

A heat exchange core which performs heat exchange between a first fluid and a second fluid, the heat exchange core comprising a circular first cross-section in which a first flow path group for the first fluid and a second flow path group for the second fluid are positioned, wherein

• first flow paths included in the first flow path group and second flow paths included in the second flow path group are annularly arranged in the first cross-section,
• the first flow path group and the second flow path group are concentrically arranged as a whole in the first cross-section,
• each of the first flow paths and the second flow paths is divided into a plurality of sections in a circumferential direction of the heat exchange core,
• each section of each of the first flow paths, and each section of each of the second flow paths, extends along an axis of the heat exchange core while spiraling around the axis of the heat exchange core,
• the sections of one of the first flow paths and the second flow paths spiral around the axis of the heat exchange core in a clockwise direction as viewed from one end side in an axial direction of the heat exchange core,
• the sections of another of the first flow paths and the second flow paths spiral around the axis of the heat exchange core in a counterclockwise direction as viewed from the one end side in the axial direction, and
• wherein for one of the first flow paths and one of the second flow paths which are adjacent to each other in a radial direction of the heat exchange core, positions of dividing walls dividing the sections in the circumferential direction of the heat exchange core in the one of the first flow paths are different, in the circumferential direction, from positions of dividing walls dividing the sections in the circumferential direction of the heat exchange core in the one of the second flow paths.