What types of fin shapes are there in tube and fin heat exchangers?

What types of fin shapes are there in tube and fin heat exchangers? What are the characteristics of each?

The fin shapes of tube and fin heat exchangers are mainly of the following types:

Flat fins: Flat fins are one of the simplest forms of fins in a tube fin heat exchanger, with the fin plane parallel to the axis of the tube and the same width and thickness of the fins. The advantages of flat fins are low manufacturing costs and easy cleaning, but the heat transfer efficiency is relatively low.

Convex fins: Convex fins are a common form of fin, with the fin plane showing a curved convex shape in relation to the axis of the tube. The advantage of externally convex fins is that they increase the strength of the tube and improve the heat transfer efficiency, but they are relatively difficult and costly to manufacture.

Inner Convex Fin: An inner convex fin is a form of fin where the plane of the fin and the axis of the tube exhibit a curved inner convex shape. Compared to externally convex fins, internally convex fins can better protect the tube wall and reduce tube wear and corrosion, but are more difficult and costly to manufacture.

Spiral fins: Spiral fins are a form of fins that are wound around the tube to form a spiral. The advantage of spiral fins is that they increase the heat exchange area and improve heat transfer efficiency, but they are more difficult and costly to manufacture.

In addition to the common fin shapes mentioned above, there are other special shapes of fins such as bowed fins, wavy fins and scratched fins. The choice of these fin shapes usually depends on the specific application needs and process requirements and can be selected according to the actual situation.