Abstract: A heat exchanger includes a first and second heat transfer plates laminated on each other. The first heat transfer plate includes two first flow ports, two first through holes, a first heat transfer region, and a first connection portion connected to one of the first flow ports and the first heat transfer region. The second heat transfer plate includes a second flow port that communicates with one of the first through holes, two second through holes, a second heat transfer region, and a second connection portion connected to the second flow port and the second heat transfer region. The second flow port is formed at a position opposite to the second heat transfer region with one of the second through holes interposed. The second connection portion is formed so as to go around an outer side of the second through hole, and includes a second protrusion portion.

Abstract: A heat exchanger that exchanges heat between a first fluid and a second fluid, includes: a first flow path through which the first fluid flows; a second flow path through which the second fluid flows; a first wall between the first flow path and the second flow path; and a second wall between the first wall and the second flow path. The first fluid flows through the first flow path in a direction intersecting a stacking direction that is a direction in which the first wall and the second wall are stacked. The second fluid flows through the second flow path in a direction intersecting the stacking direction.

Abstract: In a heat exchanger, a fluid flows in a first direction between a first opening and a second opening. The heat exchanger includes a member forming N flow path regions arranged adjacent to each other along the first direction between the first opening and the second opening. N is an integer of 2 or more. Each of the N flow path regions includes a flow path through which the fluid flows. A first flow path region and an N-th flow path region are different from each other in number and cross-sectional area of the flow paths. The first flow path region is one of the N flow path regions located to be closest to the first opening in the first direction. The N-th flow path region is one of the N flow path regions located to be N-th closest to the first opening in the first direction.

Abstract: A heat exchanger causes heat exchange between water and a refrigerant. The heat exchanger includes a first flow path through which the water flows, and a second flow path through which the refrigerant flows. A fragile portion is formed by any one of members forming the first flow path other than a partition wall partitioning the first flow path and the second flow path or any one of joining portions where members forming the first flow path are joined to each other. The fragile portion has a lower strength than the other members forming the first flow path.

Abstract: A heat exchanger configured to cause a refrigerant to exchange heat with a heat medium, includes: plates stacked on top of one another. A first flow path and a second flow path are formed between the plates. The refrigerant in a two phase state flows through the first flow path and the heat medium flows through the second flow path. Each of the plates includes: a first inlet from which the refrigerant flows into the first flow path; and a first outlet from which the refrigerant flows out of the first flow path. In each of the plates, when viewed in a direction in which the plates are stacked, the first inlet has line symmetry with respect to a center line in a width direction of the each of the plates, and the first outlet has line symmetry with respect to the center line.