Development of a general circumferentially nonuniform heat transfer fuel rod model for subchannel analysis and application to helical fuel rods  

作　　者：Junsen FU Junlong LI Xiaowen WANG Qi ZHANG Yao XIAO Hanyang GU 

机构地区：[1]School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China [2]Key Laboratory of Nuclear Power Systems and Equipment of the Ministry of Education,Shanghai Jiao Tong University,Shanghai 200240,China [3]State Key Laboratory of Nuclear Power Safety Technology and Equipment,Shanghai Jiao Tong University,Shanghai 200240,China [4]National Key Laboratory of Nuclear Reactor Technology,Nuclear Power Institute of China,Chengdu 610213,China

出　　处：《Science China(Technological Sciences)》2025年第2期15-26,共12页中国科学(技术科学英文版)

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.12075150,12322510,12135008);the Shanghai Rising-Star Program(Grant No.22QA1404500).

摘　　要：The subchannel analysis method is one of the most crucial transient safety analysis methods in the thermal design of nuclear reactors.The nonuniformity of circumferential heat transfer is slight in conventional pressurized water reactor(PWR)cores,but it is significant in advanced reactors with wire-wrapped or helical fuel rods.Predicting circumferentially nonuniform heat transfer behavior can be challenging owing to the complex geometry of helical fuel rods.In this study,a general circumferentially nonuniform heat transfer fuel rod(GCNF)model is developed to predict the fuel central temperature and circumferential heat flux and wall temperature.This model incorporates a refined two-dimensional fuel conduction model and circumferential nonuniform shape factor,addressing the dual factors contributing to the circumferential nonuniformity of helical fuel rods.An empirical correlation for the nonuniform shape factor is developed based on the computational fluid dynamics(CFD)results,and it is implemented to the subchannel code.The newly developed model is applied to a helical fuel annulus and validated by comparing the prediction results with CFD data.The maximum wall temperature predicted by the code is 1.15℃ lower than the value calculated through CFD.In terms of the heat flux,the maximum value at the inner corner is 22 kW lower than that obtained from the CFD prediction.The accurate prediction of circumferentially nonuniform heat transfer in helical fuel,concerning the surface heat flux and cladding temperature,addresses existing shortcomings in helical fuel subchannel analysis methods.Additionally,the capability to predict the fuel central temperature is essential for the safety analysis to determine whether fuel rods are melting.The generality of the model framework allows it to be used for the prediction of circumferential nonuniform heat transfer behavior in other types of fuel assemblies.

关 键 词：helical fuel rod refined fuel conduction model circumferentially nonuniform heat transfer subchannel analysis method 

分 类 号：TL331[核科学技术—核技术及应用]