METHOD OF EXPANDING CORRUGATED TUBE AND MANUFACTURING A HEAT EXCHANGER WITH EXPANSION TUBE

摘要

A method of manufacturing a heat exchanger coil, the method comprising the steps of reconfiguring the cross-sectional shape of an elongate tube from a substantially round cross-sectional shape having a first outer circumference to a reduced or corrugated cross-sectional shape having a second outer circumference which is less than the first outer circumference, forming a plurality of u-shaped hairpin tubes from the elongate tube, the u-shaped hairpin tubes each having a pair of parallel legs, inserting each of the parallel legs of the hairpin tube through a predetermined opening in at least one fin plate, attaching a plurality of return bends to the u-shaped hairpin tubes to form a predetermined circuitry and then incrementally applying fluid pressure from a fluid pressure source to an internal channel of the circuitry to incrementally expand the circuitry to form a tight heat transfer bond between the circuitry and at least one wall of the predetermined opening.