| Abstract: | Abstract Applicability of previously proposed Vold fraction correlation was studied on the boiling steam-water flows in tube. The correlation was found to be applicable to the data of Sekoguchi (d=13.55 mm) and Bartolomei (d=25mm), i.e. the value of parameter K in the correlation equals to unity. The average value of K for pipes of smaller diameter (d= 6.1, 7.7 mm) was 0.57 for both adiabatic and diabatic steam-water flows. These values of k are not dependent on flow regime, heat flux and superficial water velocity within the investigated ranges. A criterion was established with a dimensionless group Eoλ which determines the K-value as: K=1.0 for Eoλ≧2×106 and K=0.57 for Eoλ<2×106. A comparison between the predicted values by this method and experimental values at pressures from atmospheric to 80 kg/cm2 abs., heat fluxes 0–1.5×106 kcal/m2-hr, pipe diameters 5–76.2mm and gas-water volumetric flow ratios 0.06–104, showed that the present correlation is adequate within ±15% of deviation. |
