“华龙一号”反应堆精细化全堆芯大规模CFD数值模拟研究

精细化全堆芯大规模计算流体力学（CFD）数值模拟是“华龙一号”和数字化反应堆研究设计过程中的重要方法。本文通过一系列合理简化，建立了“华龙一号”反应堆全堆芯几何结构模型，并采取分组网格划分的方式对堆芯燃料组件进行离散，得到全堆芯CFD分析模型；通过精细化全堆芯大规模CFD数值模拟，可以获得堆芯完整流场分布特性和热工水力参数，验证“华龙一号”反应堆堆芯参数设计的合理性，为反应堆优化设计和安全运行提供参考。研究结果表明，由于“华龙一号”反应堆堆芯1/4对称结构和“三进三出”的1/3冷却剂进出口对称结构共同作用，堆芯流量分配因子在径向呈现先增加后减小的趋势，流量最大处不在堆芯正中心；在入口管嘴横截面上燃料组件最大温度约为331.2℃，温度分布不均匀，在径向总体呈现先增加后减小的趋势，最大温度区域也不在堆芯正中心，这与堆芯流量分配因子的趋势类似，是堆芯功率分布与冷却剂流量分配共同作用的结果。 

Fine CFD Simulation Study of Whole Core for HPR1000 Reactor Vessel

Fine and large scale CFD simulation of the whole reactor core is an important methodology in the research and design of HPR1000 and digital reactor. Based on a series of reasonable simplification of the core, the geometry model of the whole core were built for HPR1000. Meanwhile, the fuel assembly is discretized in group and the CFD model of the whole core is obtained. Besides, the distribution of flow field and the parameters of thermal hydraulics are obtained by the fine and large scale CFD simulation for the whole core. The results verify the rationality of design parameters of reactor core of HPR1000 and provide reference to the optimal design and safe operation of reactor. The results show that: due to the combined action of the 1/4 symmetrical structure of the HPR1000 reactor core and the 1/3 symmetrical structure of the coolant inlet and outlet of "three in and three out", the flow distribution factor of the core first increases and then decreases in the radial direction, and the maximum flow is not in the center of the core;the maximum temperature of the fuel assembly on the cross section of the inlet nozzle is about 331.2℃, and the temperature distribution is asymmetrical. The maximum temperature region is not in the center of the core, which is similar to the trend of the core flow distribution factor. It is the result of the joint action of the core power distribution and the coolant flow distribution.