Where do you need to use finned tubes? Let's follow the fin tube manufacturer Xing Lida to solve it!
(1) If the heat transfer coefficient on both sides of the pipe is very different, fins should be added on the side where the heat transfer coefficient is small.
Example 1: Boiler economizer, water in the pipe, flue gas outside the pipe, fins should be used on the flue gas side.
Example 2: Air cooler, the liquid in the tube, the air outside the tube, the fins should be added on the air side.
Example 3: Steam generator, the water in the tube is boiling, the flue gas is taken outside the tube, and the fins should be added to the flue gas side.
It should be noted that, at the time of design, the side with the small heat transfer coefficient should be placed outside the tube as much as possible to facilitate the installation of the fin tube.
(2) If the heat transfer coefficient on both sides of the pipe is very small, in order to enhance heat transfer, fins should be added on both sides at the same time. If there are structural difficulties, no fins may be added on both sides. In this case, if fins are added only on one side, there is no significant effect on the increase in heat transfer amount.
Example 1: A conventional tubular air preheater, the air is taken inside the tube, and the flue gas is taken outside the tube. Because it is the heat exchange between gas and gas, the heat transfer coefficient on both sides is very low, and it is very difficult to add fins in the tube, so it is necessary to use the light pipe.
Example 2: The heat pipe type air preheater, although it is still flue gas to heat the air, since the flue gas and the air flow outside the pipe, the flue pipe side and the air side can conveniently adopt the finned tube to make the heat transfer amount. greatly increase.
(3) If the heat transfer coefficient on both sides of the pipe is large, it is not necessary to use a finned tube.
Example 1: Water/water heat exchanger. When heating cold water with hot water, the heat transfer coefficient on both sides is high enough, it is not necessary to use finned tubes. However, in order to further enhance heat transfer, a threaded tube or a bellows may be used instead of the light tube.
Example 2: Power plant condenser, outside the tube is condensation of water vapor, water in the tube. The heat transfer coefficient on both sides is very high. Under normal circumstances, it is not necessary to use stainless steel finned tubes.