HEAT EXCHANGER

摘要

Disclosed is a heat exchanger which is provided with a heat-transfer pipe group in which a plurality of first heat-transfer pipes (3) for circulating a first fluid, and a plurality of second heat-transfer pipes (4) for circulating a second fluid which undergoes heat exchange with the first fluid are alternately disposed in a state of contact with one another. The heat-transfer pipe group has a coiled form which winds in the X direction orthogonal to the Y direction in which the first heat-transfer pipes (3) and second heat transfer pipes (4) are arranged one next to the other. A plurality of recesses (3a) which form protrusions on the inner peripheral surface of the first heat-transfer pipes (3) are provided on both sides in the X direction in the outer peripheral surface (31) of each of the first heat-transfer pipes (3), in the direction of extension of the first heat-transfer pipes (3).