Home > Exhibition > Content
Basic Knowledge of Finned Tubes Heat Exchangers
Aug 02, 2017

Finned tubes are used within shell and tube type heat exchangers to enhance the heat transfer efficiency between the inside and the outside of the heat exchanger tubes. Finned tubes are commercially available in various sizes and materials. Customized finned tubes are also available.

Finned Tube Design Considerations:

To be able to transfer heat well, the finned tubes material must have adequate thermal conductivity . Heat energy transfer is increased by the effective fin area on the tubes. The heat exchanger tube material will thermally expand differently at various temperatures, therefore, thermal stresses will be present along the heat exchanger. Additionally, stress will be induced by any high pressures from the applicable fluids. The tube and fin material should be compatible with all heat exchanger components and fluids for extended service periods under all operating conditions (temperatures, pressures, pH , etc.) . These requirements require careful selection of material which is strong, thermally-conductive, and corrosion-resistant.

The fin effectiveness in transferring a given quantity of heat is defined by:

Fin efficiency = (Actual Heat Transferred) / (Heat which would be transferred in entire fin area were at base temperature)

Conditions when fins do not help:

Finned tubes in selected installation will not help thermal transfer. If the convection coefficient is large, as it will be with high velocity fluids or boiling liquids, the fins may produce a reduction in heat transfer. This due to the fact that the conduction resistance then represents a larger impediment to the heat flow than the convection resistance.