HEAT EXCHANGE UNIT AND METHOD FOR MAKING IT Russian patent published in 2006 - IPC F28F1/10 

FIELD: tubular members of heat exchange apparatuses, manufacture of heat exchange apparatuses, possibly in machine engineering, heat power engineering, transporting systems, refrigerator making industry branch, oil and gas processing.

SUBSTANCE: heat exchange unit is in the form of flat tube with wall thickness S and with inner and outer fins. On both longitudinal outer sides of tube triangular walls and longitudinal grooves are formed. Width and depth of said grooves a = 0.2 - 0.5S and their pitch is in range 3 - 20 mm. Inner fins are in the form of rectangular cross section lengthwise ducts having on longitudinal horizontal walls small-height fins with height in range 0.05h - 0.5h where h - height of lengthwise duct. Width of lengthwise duct B = 0.5h - 0.3h. Outer fins are in the form of cross petal-type fins formed on outer horizontal faces of tube. Cross petal type fins are in the form of rhombs inclined relative to horizontal face of tube in cross direction and they are arranged between longitudinal grooves. On one face of flat tube cross petal-type fins are inclined to one side and on other face fins are inclined to opposite side. Cross petal-type fins are arranged with pitch t = 0.1H - 1.0 H where H - height of cross petal-type fins. Method comprises steps of undercutting layer of material in surface of heat exchanger and bending formed fins by constant bending angle at undercutting by means of cutting tool provided with rotary roller mounted in it.

EFFECT: improved intensity of heat exchange of heat exchanging cell due to increased surface of heat exchange and turbulence, simplified manufacturing process.