An Assessment of Heat Transfer Characteristics in Subcooled Flow Boiling

Experimentation has been done in subcooled flow boiling for water at pressures varying from 1 to 4 bar, velocity varying from 0.4 to 1.2 m/s, Reynolds number ranging from 4090 to 12270, heat flux ranging from 0.1 to 1.2 MIA//(sq.m) in the apparatus with a horizontal annulus test section and data were collected to determine heat transfer coefficients and compare them with existing correlations. Among the general purpose correlations considered to predict the heat transfer in subcooled flow boiling, the Thome correlation and Kandilkar's correlation predicted better than the other correlations when compared with experimental data. The parametric effect of pressure, heat flux and mass flux on heat transfer coefficients has also been evaluated. Heat transfer coefficient increases with increase in heat flux, but decreases with increase in mass flux and pressure.