栅元型格架对环形燃料子通道流动传热特性影响的数值模拟  

Numerical Simulation of Heat Transfer Characteristic with Cell Type Spacer Grid for Annular Fuel Sub-channel

作　　者：胡立强[1] 史宝磊[1] 田子豪 季松涛[1] 杨立新[2] 杨世豪 何晓军[1] HU Liqiang;SHI Baolei;TIAN Zihao;JI Songtao;YANG Lixin;YANG Shihao;HE Xiaojun(Reactor Engineering Technology Research Institute,China Institute of Atomic Energy,Beijing 102413,China;School of Mechanical,Electronic and Control Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]中国原子能科学研究院反应堆工程技术研究所,北京102413 [2]北京交通大学机械与电子控制工程学院,北京100044

出　　处：《原子能科学技术》2022年第11期2431-2437,共7页Atomic Energy Science and Technology

摘　　要：栅元型格架是一种应用于环形燃料的新型定位格架,对环形燃料外部子通道的流动传热特性具有重要影响。本文针对直通型和外扩型两种栅元格架建立13×13环形燃料多跨格架计算流体力学(CFD)计算模型,通过计算速度场分布均匀性、搅混特性、阻力特性及努塞尔数(Nu)分布,对比分析了两种格架的流动传热特性。结果表明,外扩型格架能提高子通道流场参数分布的均匀性,同时具有更优异的搅混性能。Annular fuel is a new type of fuel used in pressurized water reactor.The fuel pellets are annular shape and loaded between internal and external cladding.Annular fuel consists of two coolant channels,namely the internal channel and the external channel.The pellets can be cooled by both sides simultaneously.The spacer grid is one of the core components of annular fuel assembly,which has an important influence on flow and heat transfer characteristics.In this paper,the numerical calculation model of 13×13 annular fuel full-span grid was established for straight-through cell grid and externally-expanded cell grid based on computational fluid dynamics(CFD)method.The flow and heat transfer characteristics of the two grids were studied.Due to the symmetrical structure of annular fuel,1/8 external sub-channels were selected to evaluate the uniformity of velocity distribution by calculating the standard deviation(σ)of velocity distribution.Three evaluation factors including swirl factor,cross flow factor and turbulence intensity factor were defined,and the mixing characteristics of the two kinds of grids were analyzed based on central sub-channel.The axial heat transfer characteristics of the two grids were evaluated by calculating the average Nusselt number(Nu)distribution of the angular sub-channel,the side sub-channel and the central sub-channel.The circumferential heat transfer characteristics of fuel rods were evaluated by calculating the circumferential Nu.The resistance characteristics of the spacer grid were evaluated by comparing the axial pressure distribution of annular fuel and the resistance coefficient of the spacer grid.By comparing and calculating the coolant flow distribution ratio(φ)between the external channel and the internal channel,the adjustment effect of two kinds of grids on the flow distribution ratio was evaluated.It shows that externally-expanded cell grid can form a constricted orifice with throttling function,compared with the straight-through cell grid.It has a good regulating effect on

关 键 词：环形燃料 栅元型格架 流动传热特性 CFD方法 

分 类 号：TL33[核科学技术—核技术及应用]