Patent ID: 7823630

Claim:
A tube for a heat exchanger for performing a heat exchange of a fluid, the tube extending in a longitudinal direction and comprising a single plate having a first end portion and a second end portion opposite to the first end portion in a width direction that is perpendicular to the longitudinal direction, wherein: the single plate has a first wall surface defining a tube inner space and a second wall surface opposite to the first wall surface; the single plate is bent to have a protruding portion protruding in a mountain shape at a position adjacent to the first end portion in the width direction, and first and second planar contact portions at opposite sides of the protruding portion in the width direction; the protruding portion is configured to continuously extend in the longitudinal direction and to have a protruding tip on a side of the first wall surface, the protruding tip contacting the first wall surface of a wall portion along the longitudinal direction; the second wall surface of the first end portion contacts the first wall surface, at a position near the second end portion in the width direction, along the longitudinal direction; the first wall surface of the second end portion contacts the second wall surface of the contact portion, along the longitudinal direction; the first planar contact portion extends along the first end portion; and the first surface of the second end portion flat-contacts the second wall surfaces of both the first and second planar contact portions, along the longitudinal direction.