How to choose the corresponding finned tube for different working conditions?
Today we will share with you, how to choose a finned tube, there are the following principles:
1. If the heat transfer coefficients on both sides of the tube are very different, fins should be installed on the side with the smaller heat transfer coefficient.
A: Boiler economizer, water runs inside the tube, flue gas flows out of the tube, and fins should be used on the flue gas side.
B: Air cooler, with liquid in the tube and air flowing out of the tube, the fins should be added on the air side.
C: Steam generator, the inside of the tube is boiling water, the outside of the tube is flue gas, and the fins should be added on the flue gas side.
It should be noted that in the design, the side with the smaller heat transfer coefficient should be placed outside the tube to facilitate the installation of fins.
2. If the heat transfer coefficients on both sides of the tube are very small, in order to enhance heat transfer, fins should be installed on both sides at the same time. If there are structural difficulties, fins are not added on both sides. In this case, adding fins on only one side will not have a significant effect on the increase in heat transfer.
A: The traditional tubular air preheater uses air inside the tube and flue gas outside the tube. Because it is gas-to-gas heat transfer, the heat transfer coefficients on both sides are very low, and it is very difficult to add fins in the tube, so we had to use a bare tube.
B: Heat pipe air preheater, although the flue gas still heats the air, because the flue gas and air flow outside the tube, finned tubes can be conveniently used on both the flue gas side and the air side, so that the heat transfer is greatly increased. increase.
Finned tube radiator
3. If the heat transfer coefficients on both sides of the tube are large, there is no need to use finned tubes.
A: For water-to-water heat exchangers, when hot water is used to heat cold water, the heat transfer coefficients on both sides are high enough, so there is no need to use finned tubes. However, in order to further enhance the heat transfer, a threaded tube or a corrugated tube can be used instead of a light tube.
B: Condenser of power plant, the outside of the tube is condensation of water vapor, and the inside of the tube is water. The heat transfer coefficients on both sides are very high, under normal circumstances, finned tubes are not required.
The above is the selection of finned tube types for different working conditions that we share with you.
