【摘要】 为了分析低温流体在过冷沸腾中的相分布特性,对液氮在竖直圆管内的过冷沸腾过程进行了CFD数值模拟。通过修正气泡参量模型和改变过程的操作参数,系统地分析了空泡份额在加热上升管内的分布情况。结果表明,气液相间的热质传递决定着空泡份额的分布,截面平均空泡份额沿轴向非线性递增,沿径向呈U形分布。轴向截面平均空泡份额随着热流密度的增大而增大,随着入口质量流率和过冷度的增大而减小。更多还原

【Abstract】 To understand two-phase flow distribution patterns in subcooled boiling of cryogenic fluid,the subcooled boiling process of liquid nitrogen in an upward vertical tube was simulated by using CFD.The distribution of void fraction in the wall-heated tube was systematically analyzed through the revision of bubble models and the variation of different operating parameters.The results show that the heat and mass transfer of gas-liquid phase is the main reason influencing the distribution of void fraction.The average void fraction nonlinearly increases along the axial direction and it is U-shaped distributed along the radial direction.The average void fraction in the axial direction increases with increasing wall heat flux and decreases with increasing inlet mass flow rate and subcooled temperature.更多还原