Convective Heat Transfer Characteristics of Inner Transverse Fin Tubes

摘要

Convention heat transfer coefficient and pressure drop of inner transverse fin tubes were measured. The longitudinal fin pitch ranged from 1.1 to 2.0mm. A spiral fin tube whose number of fins and lead angle were 30 and 24°, respectively, and a plain tube were also tested for comparison. The outer diameter of test tube was 12.7mm and the length was 1.7m. Inlet water temperature of test tubes ranged from 5 to 35℃ and the difference of inlet water temperature between inner tube and outer tube was 5℃. As a result, It was showed that transverse fin tubes were more effective than spiral fin tube in case of convection heat transfer. It was also showed that the affection of inlet water temperature to convection heat transfer coefficient of transverse fin tubes could be arranged with properties value of matter. Finally, the effects of transverse fin tubes considered convection heat transfer and pressure drop were confirmed. In particular the transverse fin tube with 1.6mm fin pitch showed an excellent heat transfer coefficient at the range of low water velocity.