DNB conditions and heat transfer in the post-dryout region

Experimental data have been analyzed with respect to boundary vapour content in case of a heat exchange crisis of the second kind. The experiments are conducted within a pressure range of 70-180 atm., mass velocity varying from 350 up to 1000 kg/sq.m sec and thermal flux ranging from 2.105 up to 5.105 Cal/sq.m hr. Vapour content in the place where the temperature of the round tube wall sharply increases in the section heated is regarded as boundary vapour content. An empirical formula is suggested which helps to determine a heat emission coefficient in a beyond-crisis region for the studied range regime parameters in case vapour content varies from boundary up to 1