Internally grooved heat exchanger pipe and metal bar working roll for internally grooved heat exchanger pipes

摘要

An internally-grooved heat exchanger tube according to the present invention is structured such that the internal surface is divided into a plurality of continuous areas (W1, W2) parallel to the axial direction (L) of the tube, a large number of fins (10, 11) different in at least one selected among lead angle (, ) to the axial direction (L) of the tube, fin vertical angle (, ) and fin pitch (p, p) are formed in the adjacent areas (W1, W2), and a boundary portion (a) between the adjacent areas (W1, W2) is formed in the state of meandering to the axial direction (L) of the tube.;A metal strip machining roll for an internally-grooved heat exchanger tube according to the present invention is structured such that a plurality of roll pieces (2a, 2b) each having a large number of grooves (20, 21) on each outer surface are combined together in layers parallel to the axial direction, and a contact surface (c) of one roll piece (2a) with its adjacent roll piece (2b) forms an inclined surface.