实验研究小样品在饱和液氮中的淬冷沸腾

Experimental investigation of small sample quenchinginto saturated liquid nitrogen

用沉浸法研究了球状小样品沉浸入饱和液氮时的沸腾传热规律．实验测量了降温曲线和沉浸速度，发现当球状小样品在液氮中的运动距离为５ｃｍ，沉浸速度为１～６ｍ／ｓ时，沉浸速度对沸腾过程几乎无影响，可以认为在上述实验条件下，淬冷沸腾相当于池沸腾．实验证实了用沉浸法研究小样品的淬冷沸腾传热特性的可行性．根据实验数据，提出了计算小球的最低热流密度点（Ｌｅｉｄｅｎｆｒｏｓｔ点）热流密度的拟合公式．

Experimental investigation of the boiling of small sample quenching into saturated liquid nitrogen(LN2)is conductedThe quenching velocity is measured and the boiling curves are inversely calculated from temperaturetime curvesFrom the experimental data,it is concluded that the boiling is not influenced by the quenching speeds when the quenching distance(the moving distance of small sample in LN2)is 5 cm and quenching speed is in the range of 1～6 m/s,so that the heat flux in quenching boiling is the same as in the pool boiling in the condition as inferThe feasibility of the exploring the boiling heat flux of small sample quenching into saturated LN2 is testified experimentallyThe correlation between calculated CHF(Critical Heat Flux)point,film boiling region,Leidenfrost point heat flux of small sample quenching into saturated LN2 is developed based on experimental data