【摘要】 采用两相计算流体动力学(CFD)分析的方法,对全长尺寸格架棒束通道内过冷沸腾两相流动进行了数值模拟。将模拟得到的棒束通道中心4个子通道的平均空泡份额与实验值进行对比发现,在高空泡份额区域与实验值符合较好;在低空泡份额区域,计算值略高于实验值。两相CFD方法模拟得到了棒束通道内空泡份额的详细分布,观察到格架上游空泡份额集中在加热棒的周围,但在格架下游,子通道中心的空泡份额增加,加热棒周围的空泡份额减小,间接地证明了格架对临界热流密度(CHF)的提升作用。更多还原

【Abstract】 In this paper, two-phase CFD approach is used to simulate the subcooled boiling flow in PSBT full-size rod bundle with spacer grids. The calculated surface averaged void fraction in the central four subchannels shows good agreement with the experimental data at high void fraction conditions, while higher than the measured data at low void fraction conditions. Through CFD analysis, the effect of the spacer grid on the void distribution can be obtained. The void fraction locates majorly around the central 9 hot rods upstream the mixing vane spacer grid, while more void locates in the central region of subchannels downstream the spacer grid. The numerical simulation of boiling two-phase flow can be used for the prediction of CHF and provides a new approach for the optimization of spacer grid.更多还原