Experimental Study of Condensation Heat Transfer in Helical Coil Heat Exchanger

Abstract

Helical coils are used as one of the heat transfer enhancement techniques in many engineering applications such as in nuclear industry, chemical and petrochemical industries, HVAC systems, and many other engineering applications. In nuclear industry, helical coils are used as a method for exchanging heat in large sodium-cooled fast breeder reactor. In comparison with straight-tube heat exchangers, rate of heat transfer for helical coil heat exchanger is significantly high. This is due to secondary flow pattern in planes normal to the main flow direction of fluid in the helical coiled tube. The present work is an experimental investigation on heat transfer characteristics during steam condensing inside a small diameter vertical helical coil tube with the cooling water flowing in the shell in counter flow direction. The effect of mass flow rate and saturation temperature of steam on the heat transfer coefficient is investigated and plotted. The results confirm the significant improvement in the heat transfer coefficient for condensation of steam.