Consideration for fin parameter selection
1. The selection of fin height: from the calculation results in the above table, it can be seen that the fin efficiency is about 0.8 when the fin height is 15mm, and the fin efficiency is about 0.7. This shows that the selection of 15mms wings is appropriate, if the selection of 20mm above the wing is high, it should be particularly careful, due to its efficiency is too low, it is generally not used. For air cooling device with the aluminum fin, due to the thermal conductivity of aluminum is much higher than carbon steel, the fin efficiency is higher, the fin height increased to 22-25mm can be accepted.
2. The selection of fin pitch: the selection of small pitch, which can effectively increase the ratio of wing to wing. But in the selection of the pitch, but also to be particularly careful.
The factors to be considered are:
Properties of flow gas and the possibility of dust accumulation. Can be divided into three kinds of situations:
first, the special serious situation, such as: Iron and steel plant electric furnace, converter, and some industrial furnace exhaust, with a large amount of ash, if the use of fin tube heat, we must choose a large fin pitch. For example, the pitch in the 10mm above, but also with the auxiliary to the rational arrangement of dust and ash.
The second is ash is not very serious, but also to pay attention to the occasion. For example: industrial boilers and power plant boiler exhaust, fin pitch adopts about 8mm more appropriate, but to assisted with boast ash capacity design.
The third case is that there is no such case, such as the exhaust gas equipment, or the air cooler, and the fin pitch selection of 4-6mm is the. For air cooling of aluminum, the fin pitch is usually around 3mm.
The machining process and the machining cost of the fins are also the factors to be considered when choosing the fin pitch.
3. The selection of fin thickness: the main consideration is the corrosion and friction of the flow around the gas. For corrosion and friction serious occasions, can choose a thicker fin.
Fin height, fin pitch and fin thickness