ISSN Online: 2377-424X
International Heat Transfer Conference 5
EXPERIMENTAL STUDY OF CONDENSATION FROM STEAM-AIR MIXTURES FLOWING OVER A HORIZONTAL TUBE: OVERALL CONDENSATION RATES
Abstract
Overall condensation rates are reported for filmwise condensation from steam-air mixtures undergoing forced flow down upon a horizontal tube with saturation temperatures of 307-339 K, bulk to wall temperature differences of 1.6-25.6 K, bulk air mass fraction 0-7.8 percent and oncoming vapor velocity 0.28-0.98 m/s. For pure steam the heat transfer coefficients averaged 3.2 percent higher than predictions of
uniform heat flux Nusselt theory; the discrepancy is attributed to vapor drag. For steam-air mixtures
the reduction in heat transfer can be calculated from a correlation of the mass transfer conductance based on the asymptotic theory of Acrivos for boundary layers under strong suction.