If the finned tube heat exchangers are categorized according to the structure type, there are two basic types of longitudinal and radial types, and in terms of other types, these two types of development and deformation are examples. For a large spiral fin tube approaching the longitudinal direction, the shape of the small spiral fin tube close to the radial fin actually has a circle, a rectangle, and a needle shape. In addition, the fins can also be arranged outside the tube, called external finned tubes; they can also be arranged in the tubes, called inner finned tubes or both inside and outside.
Finned tube heat exchangers, if classified according to the manufacturing process, will also include integrated finned tubes, welded finned tubes, high frequency welding finned tubes, and mechanically connected finned tubes. First of all, for an integrated finned tube, it will be cast, machined, or rolled. The fins and the tube can also be integrated. For this welded finned tube, brazing is used. Or it is manufactured by inert gas shielded welding and other processes. With modern welding technology, fins of different materials are also used to connect together. Afterwards, finned tubes can be manufactured simply and economically, with good heat transfer and mechanical properties, and have been widely used.
Welding finned tubes in finned tube heat exchangers, because the residue in the weld is not conducive to heat transfer, this time will also cause fracture, so when producing such finned tubes must pay attention to ensure the welding process Quality; For high-frequency welding finned tubes in this equipment, this time is to pay attention to the use of high-frequency induction generated by the high-frequency generator, so that the surface of the tube and the fin contact place produces high temperature, in the depth range of about 10μm In this case, the two are melted and repressurized to join the fins and the tube.
The high-frequency welding finned tubes in the finned tube heat exchangers do not have flux, and at the same time they have solder, which is relatively simple to manufacture, and the productivity is relatively high. The heat transfer and its mechanical properties are relatively good. As far as this is concerned, in fact, it will be the most ideal type of finned tube, which is being recognized and adopted by a wide range of users.
Finally, we actually have to note that the finned tube heat exchanger is one of the earliest and most successful discoveries in the process of improving tubular heat transfer. As far as the current form is concerned, this method is still the most widely used of all different types of heat transfer enhancement methods for tubular heat exchanger surfaces. Finned-tube heat exchangers are not only suitable for use as single-finned tube heat exchangers in power, chemical, petrochemical, air-conditioning engineering, and refrigeration projects, but they are also relatively energy-efficient when used.