竖直圆管内低压过冷沸腾相分布特性实验研究

实验采用双探头光学探针对内径24 mm竖直圆管内低压过冷沸腾局部空泡份额、界面面积浓度及汽泡尺寸等局部相界面参数径向分布特性进行了研究。实验结果表明：竖直圆管内过冷沸腾相分布形态呈现轴对称特性，随着热流密度的增大，相分布形态出现近壁峰值并逐渐向中间峰值分布形态的发展，较高热流密度工况下出现轴心峰值分布；随着质量流速的增加，局部空泡份额减小，并出现中间峰值向近壁峰值分布形态的转变；随着压力的增大，局部相界面参数减小。

Experimental Study on Phase Distribution of Low-pressure Subcooled Boiling Flow in Vertical Circular Tube

Radial distributions of interfacial parameters including local void fraction, interfacial area concentration and bubble Sauter diameter were measured in low-pressure subcooled boiling flow of water in a vertical circular tube of 24 mm diameter using the double-sensor optical fiber probe.The experimental results show that the phase distri-bution in vertical circular tube is symmetrical.With heat flux increasing,the local void fraction varies from wall peaking to intermediate peaking,and core peaking can be seen under high heat flux condition.The local void fraction decreases as mass flux increases, and the phase distribution has a transition from intermediate peaking to wall peaking. Further more,it is also found that the local interfacial parameter decreases as pressure increases.