栅径比对环形燃料外周向温度分布不均匀性影响  

Influence of the pitch-to-diameter ratio on the circumferential non-uniformity of annular fuel outer temperature distribution

作　　者：曾付林 唐锚 赵鹏程[1] 向钊才 ZENG Fulin;TANG Mao;ZHAO Pengcheng;XIANG Zhaocai(School of Nuclear Science and Technology,University of South China,Hengyang 421001,China)

机构地区：[1]南华大学核科学技术学院,衡阳421001

出　　处：《核技术》2023年第9期94-102,共9页Nuclear Techniques

基　　金：国家自然科学基金(No.U21B2059);国防科工局核能开发科研项目(cosSYST等热工水力计算分析软件的自主化研发与示范应用)资助。

摘　　要：环形燃料采用紧密栅结构,燃料棒束内沿周向的温度分布存在明显不均匀性现象。本文基于ANSYS FLUENT建立了环形燃料组件计算流体力学分析模型,分析不同栅径比下正方形与六边形环形燃料组件流动换热特性,研究组件内环形燃料外周向温度分布不均匀性。研究发现:适当增大栅径比有利于环形燃料外周向温度的展平,正方形组件栅径比在1.07~1.09之间较为合适;六边形组件环形燃料外周向温度分布不均匀性略低于正方形组件,栅径比可选择在1.06~1.09之间。增大栅径比对棒间隙处温度的均匀性改善最明显,对近壁面处的温度均匀性改善次之。研究结果可为环形燃料的优化设计提供参考。[Background]The annular fuel has a closely arranged structure,and the coolant flow at both the gap between the stringers and the near wall surface is small,which is unfavorable to the coolant mixing between the subchannels and the uniform circumferential temperature distribution.[Purpose]This study aims to explore the effect of the ratio of gate spacing to gate diameter on the distribution of temperature along the circumference direction.[Methods]Based on the software code ANSYS FLUENT,a computational fluid dynamics(CFD)analysis model for annular fuel assemblies was established.Then,the calculations in hydromechanics and the numerical simulation using operating parameters of typical pressurized water reactor(PWR)were performed to analyze the coolant flow and heat transfer characteristic when the annular fuels in square or hexagonal arrangement under different grid ratios.The circumferential non-uniformity of annular fuel outer temperature distribution was investigated under circumstances of various pitch-to-diameter ratio.[Results]Computational results show that an appropriate increase of grid ratio is beneficial to the uniform circumferential temperature distribution of stringers.The appropriate grid ratio of square component is between 1.07 and 1.09,and the non-uniformity of circumferential temperature distribution of triangle component is slightly lower than that of square component.Therefore,the appropriate grid ratio is between 1.06 and 1.09.[Conclusions]The temperature distribution at the bar gap is improved most obviously by increasing the grid ratio and the improvement in the near surface takes the second.The results of this study provide a reference for the subsequent optimization design of the grid ratio of annular fuel.

关 键 词：环形燃料 周向温度分布 栅径比 子通道分析 计算流体力学 

分 类 号：TL99[核科学技术—核技术及应用]