ミクロ液膜モデルのよるサブクール沸騰の限界熱流束 : 熱工学 , 内燃機関 , 動力など

抄録

The critical heat flux (CHF) in subcooled boiling is theoretically predicted by using the microlayer model. The enhancement of heat transfer for subcooled boiling is mainly contributed by the augmented convection caused by the periodical forming and collapsing of individual bubbles. For uniform temperature surface, the CHF increases with the liquid subcooling, while the CHF approaches a constant value at high subcooling region for uniform heat flux surface. The evaporative heat transfer becomes small and the total heat flux is mainly contributed by the periodic transient heat conduction outside the evaporating area as the subcooling is increased. At low subcooling, the mechanism of CHF is the same as that in saturated pool boiling, which is due to the local dryout of microlayer. However, at high subcooling, the mean wall heat flux reaches to its maximum (CHF) because the duration of bubble condensation rapidly increases with the wall superheat.