格架对低流量对流传热影响的数值研究  

Numerical Study of Spacer Effects on Convective Heat Transfer at Low Flow Rates

作　　者：丁冠群 肖瑶[1] 高新力 刘博 李俊龙 顾汉洋[1] Ding Guanqun;Xiao Yao;Gao Xinli;Liu Bo;Li Junlong;Gu Hanyang(School of Nuclear Science and Engineering,Shanghai Jiao Tong University,Shanghai,200240,China;Nuclear and Radiation Safety Center,Ministry of Ecology and Environment,Beijing,102488,China)

机构地区：[1]上海交通大学核科学与工程学院,上海200240 [2]生态环境部核与辐射安全中心,北京102488

出　　处：《核动力工程》2022年第6期8-14,共7页Nuclear Power Engineering

基　　金：国家自然科学基金资助项目(12075150,12275174)。

摘　　要：针对带格架圆管在低流量高热流密度下的热工水力特性开展了数值研究。通过经验关联式与实验数据分别对光滑圆管内单相水低流量对流传热与格架效应进行标定,确立了基于SST k-ω模型的计算流体动力学(CFD)方法。模拟结果表明,格架下游传热特性取决于浮升力参数大小。强迫对流区与混合对流传热下降区,格架下游传热始终增强,努塞尔数呈指数衰减;混合对流传热恢复区与自然对流区,由于流场与传热的耦合作用,格架下游传热存在恶化现象,努塞尔数呈阻尼振荡。格架下游传热影响范围随着浮升力参数的增加先增大后减小。格架阻塞比越大,传热振荡越剧烈,格架致传热恶化的程度提高。该研究可为低流量堆芯内格架设计提供参考。A numerical study is carried out for the thermal-hydraulic characteristics of a circular tube with spacer at low flow rates and high heat flux.The convective heat transfer of single-phase water in a smooth circular tube at low flow rates and the spacer effects are calibrated by the empirical correlation and experimental data.A CFD method based on the SST k-ωmodel is established.The simulation results show that the heat transfer characteristics downstream of the spacer depend on the buoyancy lift parameter.For the forced convection zone and mixed convection heat transfer decreasing zone,the heat transfer downstream of the spacer is always enhanced and the Nussel number decays exponentially.For the mixed convection heat transfer recovery zone and natural convection zone,due to the coupling effect of flow field and heat transfer,the heat transfer downstream of the spacer deteriorates and the Nussel number oscillates with damping.The influence range of heat transfer at the downstream of the spacer first increases and then decreases with the increase of buoyancy lift parameters.The larger the spacer blocking ratio is,the more severe the heat transfer oscillation is,and the worse the heat transfer caused by the spacer is.This study can provide a reference for the design of core in a low-flow core.

关 键 词：格架效应 浮升力参数 混合对流 阻尼振荡 阻塞比 传热恶化 

分 类 号：TL334[核科学技术—核技术及应用]