An experimental investigation of natural convection heat transfer over outer surface of vertical helical coil condenser

Free convection heat transfer over the outer surface of helical coil condenser (HCC) and existing wire-on-tube condenser (WOTC) in air was experimentally studied under steady-state conditions. Two types of condensers are tested: namely, helical coil condenser of different coil diameter to tube diameter ratio and an existing wire-on-tube condenser. The experiments were conducted for turbulent flow outside, the helical coil surface as well as, conventional wire-ontube condenser surface and comparative analysis was done. The experimental results show that decrease in diameter ratio as well as pitch leads to increase in outside heat transfer coefficient. The heat transfer coefficient was higher 12.42% outside for the helical coil condenser in comparison with the conventional wire-on-tube condenser. It was also observed that the COP of the domestic refrigerator with designed HCC is 12.77 % higher than existing WOTC.