Experimental investigation of frictional resistance for steam-water two-phase flow in helical coils

The frictional pressure drop characteristics of steam-water two-phase flow were experimentally studied in a vertical-upward helical coiled tube, which was constructed of a 10 mm ID stainless steel tube with 301 mm coil diameter and 49-mm pitch. Experiments were performed in a wide range of system pressure 8~21 MPa, mass velocity 1200~4000 kg·m^-2·s^-1 and wall heat flux 0~1000 kW·m^-2. Effects of various control variables (pressure, steam quality, mass velocity and heat flux) on the frictional resistance were systematically investigated. Based on the experimental data, a new correlation for the calculation of the frictional pressure drop of steam-water two-phase flow at high pressures and high mass velocities in helical coils was obtained using the Chisholm's B-coefficient method.