TUBE BUNDLE HEAT EXCHANGER

The invention relates to a tube bundle heat exchanger comprising at least one channel (4, 5) that guides a heating or cooling medium, particularly a hot gas, whereby the tubes (3) of the tube bundles (2) extend in an, in essence, axially parallel manner with regard to the channel longitudinal axis (6) through the channel (4, 5), and the heating or cooling medium is guided through rings (9) and discs (10), which are arranged on and attached to the respective outer walls (7, 8) of the channel (4, 5) in an alternating manner whereby, when viewing in an axial direction of the channel (4, 5), zigzagging through the channel (4, 5) having, in essence, a circular cross-section. Inside at least one channel (4, 5), the rings (9) and discs (10) each accommodate and position all tubes (3) of a channel (4, 5) by means of cylindrical recesses (11), and the perimeter contour (12) of the rings (9) and of the discs (10) follow the mid-points (14, 15) of the outermost or innermost tube bundle tubes (3) on the medium flow-through side (13), whereby the perimeter contour (12) has a limb (16) that surrounds all outermost and innermost tubes (3).