Abstract

Results of the simulation of heat and mass transfer in wire-wrapped fuel assemblies in the anisotropic porous body approximation using the developed APMod software package are presented. The modifications introduced into the porous body model to make it suitable for wire-wrapped fuel assemblies are described. The predictions of thermal and hydraulic characteristics in the liquid-metal cooled experimental and model fuel assemblies according to this updated model are presented. An isothermal sodium flow in a Bundle 2A experimental 19-rod wire-wrapped assembly and uniform or nonuniform heating of the rods was studied. The predictions were compared with the experiments using the pressure difference across the assembly versus the coolant flowrate and the coolant temperature distribution in the assembly’s outlet section. The thermal–hydraulic characteristics in the BN-1200 reactor fuel assembly’s heated 19-rod fragment with its flow cross-section locally blocked in the central part calculated by the porous body model were compared with the predictions by the CONV-3D DNS code. Before their comparison, the distributions of local velocities, pressure, and temperature in an assembly cross-section calculated by the CONV-3D code were averaged over the averaging cells in the APMod software package. It is demonstrated that the APMod software package may be used to calculate parameters, which are averaged over a representative averaging cell, in a liquid-metal coolant flow in wire-wrapped fuel assemblies with an accuracy adequate for engineering applications.

中文翻译：

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各向异性多孔体近似中包裹式燃料组件中传热和传质的模拟

摘要

提出了使用开发的APMod软件包对各向异性多孔体近似中的线绕式燃料组件中的传热和传质进行仿真的结果。描述了多孔体模型中引入的修改，使其适用于缠绕式燃料组件。提出了根据此更新模型对液态金属冷却的实验和模型燃料组件中的热力和水力特性的预测。研究了Bundle 2A实验性19杆式绕线组件中的等温钠流以及均匀或不均匀加热杆的情况。使用组件两端的压差与冷却剂流量和组件出口部分中的冷却剂温度分布的比较，将预测结果与实验进行了比较。将BN-1200反应堆燃料组件加热的19杆碎片的热工液压特性与多孔体模型计算出的流动横截面局部阻塞在中央部分进行了比较，并将其与CONV-3D DNS代码的预测进行了比较。在进行比较之前，将CONV-3D代码计算的装配横截面中的局部速度，压力和温度分布在APMod软件包中的平均单元上求平均。事实证明，APMod软件包可用于计算参数值，这些参数在具有代表性的平均单元中，在绕线式燃料组件中的液态金属冷却剂流中具有平均精度，适合工程应用。