Patent ID: 8857505

Claim:
An integrally rolled heat exchanger tube comprising: at least one structured region on an outside of the tube having integrally rolled external ribs extending in a helical-line-shaped manner; at least one structured region on an inside of the tube comprising: primary grooves that form integral internal ribs which extend along the inside of the tube in an axially parallel or helical-line-shaped manner continuously over the circumference of the tube, said internal ribs having a height which ranges from 0.15 to 0.60 mm; secondary grooves which are spaced-apart and parallel to one another and which cross the integral internal ribs over the entire circumference of the tube, the secondary grooves having a pitch; tertiary grooves which extend continuously over the circumference of the tube, are parallel to one another, and cross the integral internal ribs and the secondary grooves over the entire circumference of the tube, the tertiary grooves having a pitch, wherein the pitch of the secondary grooves is smaller than the pitch of the tertiary grooves, and wherein an internal structure of singly-notched internal ribs with a helix-shaped superlattice structure is produced by insertion of the tertiary grooves; and smooth end pieces delimiting the structured regions, wherein the exterior diameter of the structured regions is not lager than the exterior diameter of the smooth end pieces, wherein the secondary and tertiary grooves have a notch depth, the notch depth of the secondary grooves being less than the notch depth of the tertiary grooves.