| 摘要 |
PURPOSE:To form plural small in-tube passaged and to improve the heat transfer rate of an in-tube fluid by providing a flat tube provided with plural projections on the inside surface of the tube and a fin in its tube, and allowing the fin to come into contact with the tip of the projection in the tube of the flat tube. CONSTITUTION:A plate-like fin 13 provided with a brazing filler metal on the surface is inserted into a tube of a flat tube 9 which consists of a short side 9a and a long side 9b and provided with plural projections 10 protruded from the opposite inside surface of the long side 9b. Also, by melting the brazing filler metal of the fin 13 in a heating furnace, thickness in the short side direction of the flat tube 9 is thinned to the finish dimension of the heat exchanger tube, and also, the tip of the projection 10 in the tube of the flat tube 9 and the fin 13 are allowed to adhere closely by brazing. As a result, thickness in the short side 2a direction of the heat exchanger tube 9 is made small easily, and a flow resistance of a fluid of the outside of the tube can be lowered. In this regard, since the fin 13 comes into contact with the tip of the projection 10 of the flat tube 9, a passage 12 becomes small and a thermal transfer rate of a fluid of the inside of the tube can be improved. |
