Abstract: A heat exchanger core according to an embodiment includes: a first header space; a plurality of first layered header passages; a plurality of first communication port rows; and a plurality of first passages. The plurality of first layered header passages are stacked in a perpendicular direction to a reference plane so as to each extend along the reference plane. Each first layered header passage has an open end at a first edge adjacent to the first header space and communicates with the first header space through the open end. The plurality of first communication port rows are arranged in the perpendicular direction so as to correspond to the plurality of first layered header passages, respectively. Each first communication port row is formed by a plurality of first communication ports arranged along the reference plane. The plurality of first passages communicate with any of the first layered header passages through the plurality of first communication ports.

Abstract: A heat exchanger core according to an embodiment includes: a first header space; a plurality of first layered header passages; a plurality of first communication port rows; and a plurality of first passages. The plurality of first layered header passages are stacked in a perpendicular direction to a reference plane so as to each extend along the reference plane. Each first layered header passage has an open end at a first edge adjacent to the first header space and communicates with the first header space through the open end. The plurality of first communication port rows are arranged in the perpendicular direction so as to correspond to the plurality of first layered header passages, respectively. Each first communication port row is formed by a plurality of first communication ports arranged along the reference plane. The plurality of first passages communicate with any of the first layered header passages through the plurality of first communication ports.

Abstract: Provided is a technique to achieve equalization of stress in a heat exchange core. The heat exchange core which performs heat exchange between a first fluid and a second fluid includes 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. 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.