Abstract—

The article presents the results from experimental investigations into local coolant flow fluid dynamics that were carried out on the fragmental model of a VVER-type pressurized water reactor’s mixed core consisting of two types of fuel assemblies (FAs): TVSA-T (one segment) and TVSA-T.mod.2 (two segments). The coolant flow processes in the fuel rod bundle were simulated on an aerodynamic test bench. The pressure field in the flow was measured using a five-channel pneumometric probe. The obtained pressure field in the flow was recalculated for the coolant velocity vector according to the dependences derived during calibration. For drawing up a detailed flow motion pattern, a characteristic model cross section area was separated, which included the space between the assemblies and four fuel rod rows in each TVSA-type fuel assembly. The spatial distribution of coolant flow velocity projections was analyzed, as a result of which it became possible to reveal the regularities associated with the streamlining of spacer-, mixing-, and combined-spacer grids in TVSA assemblies by coolant; to determine coolant cross flows resulting from streamlining of hydraulically nonidentical grids and determine their localization in the experimental model longitudinal and cross sections; and to reveal the effect of accumulating flow hydrodynamic disturbances in the model longitudinal and cross sections resulting from the staggered arrangement of hydraulically nonidentical grids. The results obtained from investigations of inter-assembly interaction of coolant between the neighboring TVSA-T and TVSA-T.mod.2 assemblies have been adopted for practical use at AO Afrikantov OKBM in estimating the thermal reliability of VVER-type reactor cores and have been included in the database for verification of computation fluid dynamics computer programs (CFD codes) and detailed cell-wise numerical analysis of the core of VVER reactors.

中文翻译：

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VVER反应堆混合堆芯内冷却剂流动局部流体动力学的数值和实验研究相结合

摘要—

本文介绍了对局部冷却剂流动流体动力学的实验研究结果，该研究是在VVER型压水堆混合堆芯的碎片模型上进行的，该堆芯由两种类型的燃料组件（FA）组成：TVSA-T（一个段）和TVSA-T.mod.2（两个部分）。在空气动力学试验台上模拟了燃料棒束中的冷却剂流动过程。流量中的压力场是使用五通道气敏探针测量的。根据在校准过程中得出的相关性，针对冷却剂速度矢量重新计算流中获得的压力场。为了绘制详细的流动运动模式，将特征模型的横截面区域分开，其中包括组件之间的空间和每个TVSA型燃料组件中的四根燃料棒排。分析了冷却剂流速预测的空间分布，结果有可能揭示出冷却剂使TVSA组件中的间隔，混合和组合间隔格流线化的规律性。确定由于水力不相同的网格的流线化而产生的冷却剂横流，并确定它们在实验模型的纵向和横截面上的位置；并揭示了由于水力不相同的网格的交错布置而在模型的纵向和横截面中累积流动水动力扰动的影响。通过研究相邻TVSA-T和TVSA-T.mod之间的冷却液的组件间相互作用获得的结果。