Why use finned tube in Heat Exchanger?
Recently Cangzhou Steel Pipe & Fitting Co., LTD, is attending a boiler renovation project of Rosneft Oil, the project is finned tubes of A335 P11 alloy steel, the one length is 10-12.8m.
Finned tubes are heat exchange element, commonly used in applications involving the heat transfer from a hot fluid to a colder fluid through tube wall. The rate at which such heat transfer can occur depends on three factors: (1) the temperature difference between the two fluids; (2) the heat transfer coefficient between each of the fluids and tube wall; (3) the surface area each fluid exposes. In the case of a bare (unfinned) tubes, where the outside surface area is not significantly greater than the inside surface area, the fluid with the lowest heat transfer coefficient will dictate the overall heat transfer rate. When the heat transfer coefficient of the fluid inside the tube is several times larger than that outside the tube, the overall heat transfer rate can be greatly improved by increasing the outside surface of the tube. So the principle of finned tubes is to increase the outside surface area of the tube.
By increasing the outside surface area of tubes, the overall heat transfer rate increased, thereby reducing the total number of tubes required for the given application. This reduces the overall equipment size and the cost of the project. In many cases, one finned tube replaces six or more bare tubes and less than 1/3 the cost and 1/4 the olume.
If you also need finned tubes, please don’t hesitate to contact me.