Incipient Boiling Characteristics at Atmospheric and Subatmospheric Pressures

Abstract

Experimental data are reported for incipient boiling of water, refrigerant R-113, and methanol from a flat horizontal stainless steel surface of known surface roughness. The work was carried out over a pressure range of 1, 0.5, and 0.25 atm. Overshoot temperatures at incipience for R-113 and methanol were systematically investigated and found to exist for all pressures employed. The overshoot in temperature at incipience did not occur for water within the experimental range covered. Surface temperature fluctuations were found to increase in amplitude with decreasing pressure, reaching a maximum at incipience. In general, these temperature fluctuations became less pronounced as fully developed nucleate boiling became established. An abnormal occurrence of transition from single-phase free convection to film boiling is also reported.