液氮过冷沸腾壁面换热特性的数值研究

应用计算流体力学(CFD)研究手段,对液氮过冷沸腾过程进行了模拟。系统分析了过冷沸腾壁面换热过程中存在的各传热模式,得到3部分热流沿管长的分布规律。计算结果表明,在过冷沸腾后期,蒸发热流成为壁面换热的主要模式。同时,就壁面热流密度的变化对3部分热流的影响进行了分析。随着壁面热流的增加,过冷沸腾出口处淬火热流和对流热流将减小,只有蒸发热流增大,且所占总热流份额绝对占优,壁面热流的增加促进了沸腾换热。

Numerical investigation on wall heat transfer characteristics of subcooled boiling of liquid nitrogen

The subcooled boiling of liquid nitrogen was numerically simulated by means of computational fluid dynamics(CFD).The different heat transfer modes of surface heat transfer during subcooled boiling were systematically analyzed and the distribution of the three components of wall heat flux along the tube was obtained.The results show that the heat flux transferred by evaporation is the leading mode of surface heat transfer at the final region of subcooled boiling.Meanwhile,the effect of wall heat flux on the ...