Performance comparison of finned tubes

Performance comparison of finned tubes

1. The heat transfer performance of finned tubes is related to the contact thermal resistance between fins and tubes, and the contact thermal resistance depends on the contact pressure between them. Obviously, the heat transfer performance of the welding and sleeve type is better, followed by the bimetal rolling type, and the insert type and the winding type are worse. After twice rolling, the contact area of KLM finned tube increases by about 50%, and it is not affected by the tolerance of outer diameter of the tube. After many cold and hot cycles, it can still maintain good contact, so the contact thermal resistance is small and the heat transfer performance is high. The total heat transfer coefficient of slotted fin tube can be increased by about 20% because of the disturbance of airflow.

2. Finned Tube temperature resistance

When the temperature of finned tube wall increases, the contact pressure between finned tube and tube will change, and the contact thermal resistance will also change. The change value depends on the type of finned tube and the initial contact pressure. The fin tension of the winding type decreases rapidly with the increase of temperature, so the contact thermal resistance increases rapidly, while the bimetal rolling type can keep stable in a larger temperature range.

3. Finned Tube ability to withstand atmospheric corrosion

The fin tube is protected by fins to resist atmospheric corrosion. Different types of finned tubes have different atmospheric corrosion resistance due to their different protection areas. The protection capability of all kinds of finned tubes is the most J of bimetal rolled plates. As for all finned tubes treated by surface hot dip galvanizing, the ability to withstand atmospheric corrosion is also the strongest. In chemical plants or coastal areas where some corrosive gases are contained in the atmosphere, attention should be paid to the selection of materials and types of finned tubes. Aluminum fins are susceptible to corrosion.

4, Finned tube's the pressure resistance inside the pipe.

Many working pressures of finned tube depend on the material and wall thickness of the base tube, but also on the type of finned tube. The pressure resistance of rolled fin tube (base tube is aluminium and copper) is very low, and the distribution of copper-aluminium composite fin tube is not suitable for air cooler. There is a rolling groove on the inserted tube, and its working pressure decreases with the increase of working temperature.

5. Finned Tube cleaning up dirt

Finned tube air side dust cleaning usually uses compressed air, steam or high pressure water. Using this method, the fins must be rigid.

6. Finned Tube manufacturing costs

From the material consumption of fins, the winding type is lower, the bimetal rolling plate and the sleeve type are higher. The bimetal rolled aluminum consumes more than 1/3 to 1/2. From the cost of manufacturing process, the winding type is lower, the bimetal rolling plate is higher, and the sleeve type is the most G. All the finned tubes which need to be hot-dipped galvanized in and out of the surface and the copper-aluminium composite finned tube supply, regardless of material consumption or manufacturing process, the manufacturing cost is relatively high.