Analysis of Two-Phase Flow Pressure Drop in Inclined Annular Channel

The experiment is investigated under the condition of: P=1~3 MPa, G=190~1 050 kg/（m²·s）, ΔT_sat=20~70℃, q=304~1873 kW/m² in an annular channel which is heated by a tube at its center with the co-current stream-water system. By analyzing the change of forces, a criterion for working out how pressure drop is influenced by inclination and void fraction has been developed. Based on the criterion, a modified two-phase flow pressure drop correlation for angles from vertical upward to horizontal has been developed. The result indicates that the modified correlation is fit for calculating the pressure drop of two-phase flow in the inclined channel.