Numerical investigation on boiling crisis characteristic of a 7-rod HCF assembly in hexagonal lattice

IF 3.3 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy Pub Date : 2024-11-07 DOI:10.1016/j.pnucene.2024.105528

Zijian Huang , Hongkang Tian , Mengke Cai , Tenglong Cong , Yao Xiao , Hanyang Gu

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引用次数: 0

Abstract

Helical cruciform fuel (HCF) has the advantages of larger heat transfer area, enhanced coolant mixing and self-supporting, which contribute to increasing power density and safety margins. Compared with the square lattice configuration, the hexagonal arrangement of HCF assembly is more compact, which can help achieve a higher power density. In this paper, the flow characteristics and heat transfer behaviors of HCF in hexagonal lattice were predicted at high and low vapor quality during boiling crisis based on Eulerian two-fluid model. The influence of twist pitches and cross-sections of the fuel rod on heat transfer efficiency and fuel temperature was also studied. The cross-flow intensity changed periodically with a 30° cycle at low vapor quality, and did not fluctuate periodically at high vapor quality, which decreased with the increase of flow resistance. The highest heat flux of HCF rod was the at the blade root and the lowest was at the blade tip, and the maximum to average heat flux ratio was about 1.8. The peak vapor fraction and temperature occurred at leeside side of the fuel rods. The increase of the twist pitch reduced the critical heat flux (CHF), and the increase of blade length enhanced the non-uniformity of heat flux distribution. During boiling crisis, the maximum temperature of the fuel was lower than the phase transition temperature of U-50 wt%Zr alloy, which means the cladding meltdown caused by boiling crisis will occur before phase transition of the fuel.

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六方格中 7 杆 HCF 组件沸腾危机特征的数值研究

螺旋十字形燃料（HCF）具有更大的传热面积、更强的冷却剂混合和自支撑等优点，有助于提高功率密度和安全裕度。与方形晶格构型相比，六边形排列的 HCF 组件更加紧凑，有助于实现更高的功率密度。本文基于欧拉双流体模型，预测了沸腾危机期间六边形晶格中 HCF 在高蒸汽质量和低蒸汽质量下的流动特性和传热行为。此外，还研究了燃料棒的扭曲间距和横截面对传热效率和燃料温度的影响。在低蒸汽质量时，横流强度以 30° 为周期周期性变化，而在高蒸汽质量时，横流强度没有周期性波动，且随着流动阻力的增加而减小。HCF 棒的最高热通量出现在叶片根部，最低热通量出现在叶片顶端，最大热通量与平均热通量之比约为 1.8。蒸汽分数和温度峰值出现在燃料棒的左侧。捻距的增加降低了临界热通量（CHF），叶片长度的增加增加了热通量分布的不均匀性。在沸腾危机期间，燃料的最高温度低于 U-50 wt%Zr 合金的相变温度，这意味着沸腾危机导致的包壳熔化将发生在燃料相变之前。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Progress in Nuclear Energy 工程技术-核科学技术

CiteScore

5.30

自引率

14.80%

发文量

331

审稿时长

3.5 months

期刊介绍： Progress in Nuclear Energy is an international review journal covering all aspects of nuclear science and engineering. In keeping with the maturity of nuclear power, articles on safety, siting and environmental problems are encouraged, as are those associated with economics and fuel management. However, basic physics and engineering will remain an important aspect of the editorial policy. Articles published are either of a review nature or present new material in more depth. They are aimed at researchers and technically-oriented managers working in the nuclear energy field. Please note the following: 1) PNE seeks high quality research papers which are medium to long in length. Short research papers should be submitted to the journal Annals in Nuclear Energy. 2) PNE reserves the right to reject papers which are based solely on routine application of computer codes used to produce reactor designs or explain existing reactor phenomena. Such papers, although worthy, are best left as laboratory reports whereas Progress in Nuclear Energy seeks papers of originality, which are archival in nature, in the fields of mathematical and experimental nuclear technology, including fission, fusion (blanket physics, radiation damage), safety, materials aspects, economics, etc. 3) Review papers, which may occasionally be invited, are particularly sought by the journal in these fields.