摇摆对低流量对流传热格架效应影响的数值研究  

Numerical Study of the Influence of Rolling Motion on the Spacer Effect of Low Flow Convective Heat Transfer

作　　者：李楠 丁冠群 肖瑶[1] 李俊龙 顾汉洋[1] Li Nan;Ding Guanqun;Xiao Yao;Li Junlong;Gu Hanyang(School of Nuclear Science and Engineering,Shanghai Jiao Tong University,Shanghai,200240,China)

机构地区：[1]上海交通大学核科学与工程学院,上海200240

出　　处：《核动力工程》2023年第6期54-62,共9页Nuclear Power Engineering

基　　金：国家自然科学基金(12275174,12075150);上海市青年科技启明星计划(22QA1404500);中核集团青年英才计划菁英项目。

摘　　要：针对摇摆条件下低流量对流传热格架效应开展了数值研究。基于实验数据对摇摆模型进行了验证,确立了基于SST k-ω湍流模型的计算流体动力学(CFD)方法。结果表明:①对周向平均时均传热,摇摆会增强低流量工况格架下游传热。但在混合对流恶化恢复区和自然对流区,格架效应仍存在阻尼振荡衰减现象,且振荡幅度减小;②对局部时均传热,热点始终位于垂直摇摆轴方向,摇摆弱化该方向传热,且该方向格架导致的传热弱化现象被进一步增强;③对热点位置瞬时传热,计算工况中瞬时传热系数的最大弱化程度较充分发展稳态可达40%,安全分析中需重点关注。A numerical study was carried out on the spacer effect of low flow convective heat transfer under rolling motion.The rolling model was verified based on the experimental data,then a model-based computational fluid dynamics(CFD)method was established.The results show that for the circumferential mean time-averaged heat transfer,the heat transfer downstream of the spacer is enhanced under low flow conditions.However,in the mixed convection deterioration recovery area and natural convection area,the spacer effect still has damping oscillation attenuation,and the oscillation amplitude decreases.For local time-averaged heat transfer,the hot spot always lies in the direction of vertical rolling axis,and the heat transfer is weakened in that direction under rolling motion,and the heat transfer weakening caused by the spacer in that direction is further enhanced.For the instantaneous heat transfer at the hot spot,the maximum weakening degree of the instantaneous heat transfer coefficient can reach 40%of the fullt developed steady state,which needs to be paid attention to in safety analysis.

关 键 词：摇摆 格架效应 指数衰减 阻尼振荡 传热恶化 

分 类 号：TL334[核科学技术—核技术及应用]