The effects of initial conditions on transient CHFs caused by rapid pressure reductions from initial non-boiling or nucleate boiling regime

摘要

It was made clear that the trends of the transient CHF (q{sub}(cr)) and the elapsed time (t{sub}m) from starting point to the q{sub}(cr) for intermediate and high initial heat fluxes (q{sub}(in)) caused by a rapid pressure reduction with a short reduction period (τ{sub}p) have minimum points respectively for the q{sub}(in) with natural convection regime near the minimum q{sub}(in) with nucleate boiling one. The minimum q{sub}(cr) at which the transition to film boiling occurred semi-directly with increasing of heat flux from transient convection regime: the q{sub}(cr) value was considerably lower than corresponding steady-state CHF.