Experimental Investigation of Heat Transfer Depending on Inclination Angle of Unfinned, Axial Finned and Radial Finned Heat Exchangers

In this study, effects of axial and radial fins on a circular pipe and inclination angle were investigated experimentally for natural convection heat transfer. An unfinned circular pipe was utilized as reference. Experiments were carried out at 00,300,600 and 900 pipe inclination angles to measure natural convection heat transfer. Hot water was used as heat source during the experiments. The water in a storage tank was kept at a constant temperature and it was circulated through heat exchanger. Radiation heat transfer was also taken into consideration. Rayleigh number varied between Ra≈10 × 106 and 60 × 106. The highest calculated Nusselt number was found as about Nu≈408 for axial finned heat exchanger. All finned surfaces and inclination angles lead to better heat transfer performances comparing to the unfinned heat exchanger.