FLAT HEAT TRANSMISSION TUBE, METHOD FOR MANUFACTURING CROSS-FIN-TUBE-TYPE HEAT EXCHANGER PROVIDED WITH SAME, CROSS-FIN-TUBE-TYPE HEAT EXCHANGER MANUFACTURED USING SAID METHOD

摘要

This flat heat transmission tube (1) is used in a cross-fin-tube-type heat exchanger provided with: the flat heat transmission tube (1), which has a bent portion, there being a plurality of holes (2) penetrating in the axial and parallel directions formed in the flat heat transmission tube (1); and a plurality of tabular fins welded to the flat heat transmission tube (1), wherein in the cross-section of the part of the flat heat transmission tube (1) corresponding to the bent portion before being bent, the distance (t₁1) between the outer surface of the flat heat transmission tube (1) and the inner surface of a hole (2) in a part bending with a small curvature when bending is performed is larger than the distance (t₁2) between the outer surface of the flat heat transmission tube (1) and the inner surface of a hole (2) in a part bending with a large curvature when bending is performed.