ISSN Online: 2377-424X
International Heat Transfer Conference 5
FLOW BOILING IN SUBCOOLED AND LOW QUALITY REGIONS − HEAT TRANSFER AND LOCAL VOID FRACTION
Sinopsis
Experimental results of the heat transfer and phase distribution in the flow boiling with inlet subcooling are reported. The phase distribution measurements were made on the spacial (i.e., radial and axial) distributions of void fraction and bubble frequency, which corresponds to the number of bubbles in contact with an electric probe tip per unit time. These phase profiles are compared with those of the flow boiling simulator using the air-water two-phase fluids, into which air is introduced through a porous tube wall. A bubble sublayer was found in the boiling experiments as well as had been recognized in the air-water flow boiling simulation results (l). Test data show that the void fraction of the bubble sublayer has a close relationship to heat transfer coefficient. An empirical correlation is also presented for the onset of bubble departure.