1. Increase the heat transfer area outside the tube? Improve the heat transfer efficiency. The spiral finned tube expands the heat transfer area outside the smooth tube. Therefore, its convective heat transfer surface is composed of two parts: the expanded surface and the smooth tube surface. In the case of the same volume, Its heat exchange area is several times that of a bare tube? Therefore, the heat exchange capacity of the outside of the tube and the heat transfer efficiency of the heat exchanger are significantly improved.
2. The compact structure of the spiral fin tube bundle increases the heat exchange area per unit volume? So compared with the light tube bundle, the number of tube rows in the fin tube bundle is relatively small, which can reduce the heat exchange when the heat exchange is the same. The volume of the device, so that the structure is compact, and the metal consumption is reduced.
3. Enhanced heat transfer conditions. The spiral finned tube through its outer curved structure channel causes the flow boundary layer to separate and develop periodically. It reduces the thickness of the boundary layer and shortens the length of the laminar boundary layer. These are all helpful to destroy the boundary layer. Laminar flow bottom layer? So it plays a role in enhancing heat transfer.
4. Reduce the flow resistance of the fluid outside the tube and save operating costs. In the case of the same gas flow rate on the fin side, the resistance of each row of spiral fin tube bundles is greater than the resistance of each row of light tubes, but the fin tube bundle is better than that of the light tube bundle. The heat exchange area of the rows is greatly increased. Under the same heat exchange amount, the number of rows of the tube bundle can be reduced, so that the total resistance of the heating surface is reduced.
5. Reduce the wear of the heating surface. In the boiler burning solid fuel, when the ash-containing air flows through the heating surface, impact and cutting the heat exchange surface will cause the wear of the heating surface, and the amount of wear is proportional to the third power of the fluid velocity. . As the heat transfer capacity of the spiral fin tube bundle is improved, the velocity of the fluid outside the tube can be reduced, which greatly reduces the abrasion of the heating surface.