Abstract This paper compares CFD simulation results of a boron dilution scenario with experimental results. The simulation was carried out with ANSYS CFX using the SST turbulence scheme, experimental data were produced in the ROCOM test facility, experiment E2.3. The main features of the scenario are asymmetric, transient mass flow conditions in the affected loops 1 and 2 of a KONVOI-type reactor vessel and reduced density of the underborated coolant slugs fed into the reactor trough the cold legs of both loops. The CFD simulation was able to capture the density stratification in the loops affected by underboration and the mixing in the downcomer and in the lower plenum. Good agreement with the experiment was obtained for the temporal evolution of average boron concentration in several measuring sections of the reactor vessel and of the boron distribution in the core inlet. In general, minimum values of boron concentration were found to be lower in the simulation than in the experiment.

中文翻译：

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压水堆中复杂硼稀释瞬变的建模——根据 ROCOM E2.3 实验验证使用 ANSYS CFX 的 CFD 仿真

摘要 本文将硼稀释方案的 CFD 模拟结果与实验结果进行了比较。模拟使用 ANSYS CFX 使用 SST 湍流方案进行，实验数据在 ROCOM 测试设施中生成，实验 E2.3。该情景的主要特征是 KONVOI 型反应堆容器受影响的回路 1 和 2 中的不对称、瞬态质量流量条件，以及通过两个回路的冷腿送入反应堆的低硼化冷却剂段塞的密度降低。CFD 模拟能够捕捉到受钻井不足影响的回路中的密度分层以及下降管和下部压力通风系统中的混合。反应堆容器几个测量部分中平均硼浓度的时间演变和堆芯入口中硼分布的时间演变与实验非常吻合。通常，在模拟中发现硼浓度的最小值低于实验中。