【摘要】 为研究定位格架对棒束通道热工水力特性的影响，基于欧拉双流体模型和改进的壁面沸腾模型以及众多子模型，建立了棒束通道内流体过冷沸腾多相流模型，与实验对比验证了过冷沸腾模型的准确性。利用CFD软件STAR-CCM+对流体在4×4棒束通道内的流动沸腾现象进行模拟，研究格架对CHF、压力、空泡份额和二次流等热工水力参数的影响，获得多工况下棒束通道内的CHF和流场、温度场分布。结果表明，在压力12～14 MPa、质量流速1 000～1 200 kg/(m~2·s)、平衡含汽率0.15～0.25的参数区间内，此格架引起CHF提升20%以上，平均二次流最大值增加6倍以上，截面平均最大空泡份额减少27.5%以上，棒束通道总压降增大0.9倍以上。更多还原

【Abstract】 In order to study the influence of the grid on thermal-hydraulic characteristics in the rod bundle channel, a subcooled boiling multiphase flow model of the fluid in the rod bundle channel has been established based on the Eulerian two-fluid model and the improved wall-boiling model as well as a number of sub-models, and the accuracy of the subcooled boiling model has been verified by comparing it with the experiments. The CFD software STAR-CCM+ was used to simulate the flow boiling of fluid in a 4×4 rod bundle, to study the influence of the grid on the thermo-hydraulic characteristics such as CHF, pressure, volume of vapor, and secondary flow, and to obtain the CHF and distributions of flow and temperature fields in the rod bundle channel under multiple operating conditions. The results show that in the parameter interval of the pressure 12-14 MPa, the mass flow rate 1 000-1 200 kg/(m~2·s), and the equilibrium quality 0.15-0.25, the grid induces a CHF enhancement of more than 20%, an increase in the average secondary flow maximum by more than 6 times, a reduction of maximum volume of vapor by more than 27.5%, and an increase in the total pressure drop in the rod bundle channel by more than 0.9 times.更多还原