铅冷快堆主换热器内冷却剂流动换热特性研究  

Study on the Flow and Heat Transfer Characteristics of Coolant in the Primary Heat Exchanger of the Lead-Cooled Fast Reactor

作　　者：李良星 向祖涛 赵佳元 许向阳 石尚 LI Liangxing;XIANG Zutao;ZHAO Jiayuan;XU Xiangyang;SHI Shang(State Key Laboratory of Multiphase Flow in Power Engineering,Xi'an Jiaotong University,Xi'an of Shaanxi Prov.710049,China)

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,陕西西安710049

出　　处：《核科学与工程》2024年第4期853-863,共11页Nuclear Science and Engineering

基　　金：国家重点研发计划(NO.2020YFB1902104)。

摘　　要：铅冷快堆由于其优秀的热工水力性能和安全性能,在商业发电和动力装置应用上具有良好的应用前景。以液态铅铋合金(LBE)和超临界二氧化碳(SCO_(2))为工质的主换热器作为连接铅冷快堆一、二回路的关键设备,其热工及安全性能对反应堆的运行效率及运行安全有重要影响。为了研究铅冷快堆主换热器内流动换热优化方案,针对铅冷快堆主换热器编写了设计和校核计算程序,借助等换热功率分段模型获得了设计工况下主换热器的关键热工水力参数;基于相似原理构建了缩比模型,对使用外置式导流筒时换热器内的流动情况进行了数值模拟;对比分析了换热器分别使用直管和螺旋扁管时流体的流场、温度场分布。研究结果表明,增设外置式导流筒减小了LBE在换热器壳侧流动的最大流速,改善了流场;螺旋扁管相较于直管换热器增大了总换热功率约1.68倍,管侧和壳侧的温度和速度分布更加均匀,改善了换热器的整体换热性能。The lead-cooled fast reactors(LFR)are fast neutron spectrum reactors cooled by molten lead or lead alloys,which are recommended as one of candidates for the next generation of nuclear reactors due to the high performance in sustainability,thermal-hydraulics,and security features.As the critical equipment linking the primary circuit and secondary circuit in LFR,the performance of the primary heat exchanger plays a significant role in the operating efficiency of the reactor.In order to study the optimization scheme of the flow and heat transfer in the primary heat exchanger of a lead cooled fast reactor,a design and verification calculation program was developed for the main heat exchanger of the lead cooled fast reactor.The key thermal hydraulic parameters of the main heat exchanger under design conditions were obtained using an equal heat transfer power segmented model.Based on the principle of similarity,the scaled model was constructed to numerically simulate the flow inside the heat exchanger when using the external flow distributor.A comparative analysis was conducted on the flow field and temperature distribution of the fluid when using straight and twisted tubes in the heat exchanger.The results show that the external flow distributor reduces the maximum flow velocity of LBE on the shell side of the heat exchanger and improves the flow field.Compared to straight tube heat exchangers,twisted tubes increase the total heat transfer power by about 1.68 times,while temperature and velocity distribution on the tube and shell sides are more uniform,so that the the overall heat transfer performance of the heat exchanger is improved.

关 键 词：铅冷快堆 主换热器 数值模拟 螺旋扁管 外置式导流筒 

分 类 号：TK172[动力工程及工程热物理—热能工程]