Heat exchanger with tube bundle comprising at least two sections

A heat exchanger with a tube bundle which is wound in a helical manner about a longitudinal axis, wherein the tube bundle comprises at least two tube sections which are placed adjacent to one another in the direction of the longitudinal axis, each tube section comprising a helically wound tube defining a helical winding about the longitudinal axis so as to form coils, the adjacency being such that the coils are uniformly spaced over the entire tube bundle, the helically wound tube of said each tube section having an internal cross-section which is constant over the helical winding of the helically wound tube, wherein the at least two tube sections which are placed adjacent to one another in the direction of the longitudinal axis each comprise a tube which is wound in a helical manner with two ends thereof directed towards an exterior of a helix in directions which are mutually parallel or angled and which are parallel or angled with respect to a radial direction, a completion insert being provided in order to close a space between facing ends, which are adjacent to one another, of two respective tubes of adjacent tube sections, the facing ends comprising an outlet end of one of the adjacent tube sections and an inlet end of the other of the adjacent tube sections.