Patent ID: 8261816

Claim:
A heat exchanger, comprising: a plurality of stacked flat tubes, said tubes having facing broad sides adjacent one another in the stacking direction and first and second open ends; a collecting tank connected to at least one of the first and second open ends of said stacked flat tubes at a first connection plane, said first connection plane defined by a tube plate; and internal inserts in said flat tubes, the inserts having wave crests and troughs defining flanks therebetween extending in a direction substantially parallel to a flow path of a first medium from the first to the second open end of the plurality of flat tubes, the inserts being bonded between said broad sides of said tubes at the wave crests and troughs, and including a corrugation extending in parallel to the flow path along at least one of the flanks from said at least one of the first and second open ends and terminating at a point proximal to the first connection plane, the flank flexing in the stacking direction at the corrugation during thermal cycling, wherein at least one of the flanks is continuous along a substantial portion of the flow path beyond the tube plate.