Transition flow boiling heat transfer to water in a vertical annulus

Abstract

Transition boiling heat transfer coefficients for water at 25–30 psia flowing upward at low velocities have been obtained Hot mercury, flowing on the inside of a tube with a 0.54 in. o.d. served as the heat source. Water flowed in the annular space between the heat source and an outer glass tube having a 1 in. dia. Thermocouples placed at several elevations within the mercury stream allowed the rate of heat transfer to be determined. The heat transfer coefficients appear consistent with other transition boiling data providing an appropriate allowance is made for the reduction in critical heat flux at high void fractions.