HEAT TRANSFER TUBE WITH CRACK-LIKE CAVITIES TO ENHANCE PERFORMANCE THEREOF

摘要

A heat transfer tube (20) having an inner surface (24) provided with a dense pattern of polyhedrons (100) having crack-like cavities (80) on at least two surfaces of a single polyhedron (100), forming three-dimensional crack-like cavities (80) that enhance flow evaporator heat transfer. The tube (20) is made by (a) forming in an inner surface for the tube a plurality of generally parallel first grooves (70), (b) forming in the inner surface (24) and over the first grooves (70) a plurality of generally parallel second fins (64) extending at a first angle of between 0 and about 25 degrees relative to a longitudinal axis (26) for the tube (20) to thereby devolve the second fins (64) into the pattern of cavities, and (c) forming in the second fins (64) a pattern of generally parallel crosshatches extending cross-wise thereto.