Selection Principles Of Fin Parameters For Finned Tubes

1, Fin height selection
For engineering commonly used high-frequency welding finned tube, when the fin height of 15mm, fin efficiency of 0.8 or so, and when the fin height of 20mm, the fin efficiency down to 0.7 or so. This shows that the choice of 15mm fin height is appropriate, if the choice of 20mm above the fin height, be especially careful, because of its fin efficiency is too low, generally not be used. For the air cooler with aluminium fins, due to the thermal conductivity of aluminium is much higher than carbon steel, its fin efficiency is higher, the fin height to 22-25mm is also acceptable.

2, Fin Pitch Selection
Select a small pitch, can effectively increase the finning ratio. But in the choice of pitch, but also to be particularly careful. Factors to be considered are
(1) the nature of the winding gas and the possibility of ash accumulation. Can be divided into three cases.
First, the accumulation of particularly serious occasions, such as: iron and steel mills, converters, and some industrial furnace exhaust, ash content is very large, if the finned tube heat transfer, we must choose a large fin pitch. For example, the pitch of 10mm or more, but also supplemented by a reasonable design and selection of soot blower.
The second situation is not necessarily very serious ash accumulation, but also to give attention to the occasion, for example: power station boilers and industrial boilers exhaust, fin pitch using 8mm or so is more appropriate, but supplemented by the ability to have a self-blowing ash design.
The third situation is no accumulation of ash or accumulation of light occasions, such as combustion of natural gas equipment exhaust, or air cooler, the fin pitch selection of 4-6mm is possible. For aluminium air coolers, the fin pitch is often around 3mm.
(2) Fin processing technology and processing cost is also in the selection of fin pitch should be considered.

3,Fin thickness selection
Mainly consider the corrosion and wear and tear of the winding gas. For corrosion and friction loss of serious occasions, can choose thicker fins.