液态燃料熔盐堆排盐罐非能动余热排出特性研究  

Passive residual heat removal characteristics of liquid fuel molten salt reactor salt drain tank

作　　者：渠鹏荣 周翀 王纳秀[1,2] 邹杨 王善武[1,2] QU Pengrong;ZHOU Chong;WANG Naxiu;ZOU Yang;WANG Shanwu(Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海应用物理研究所,上海201800 [2]中国科学院大学,北京100049

出　　处：《核技术》2023年第5期95-106,共12页Nuclear Techniques

基　　金：国家重点研发计划(No.2020YFB1902000);上海市"基础研究特区计划"(No.JCYJ-SHFY-2021-003)资助。

摘　　要：液态燃料熔盐堆具有较高的经济性、安全性及燃料在线处理等多种特点。紧急排盐非能动余热排出系统(Emergency Draining Salt Passive Residual Heat Removal System,EDS-PRHRS)是液态燃料熔盐堆独有的余热排出系统设计,其中排盐罐中熔盐能否安全导出余热是EDS-PRHRS设计的基础。为了研究EDS-PRHRS排盐罐运行过程中的瞬态特性,本文以30 MW熔盐堆紧急排盐罐为研究对象,通过计算流体力学分析软件Fluent对EDS-PRHRS排盐罐进行熔盐耦合换热元件的余热排出瞬态数值模拟,并针对排盐罐相关参数进行敏感性分析。分析结果表明:余热排出过程中换热元件外壁面和熔盐热点温度随时间变化存在峰值,且通过提高换热元件轴向高度、增强气隙层壁面发射率可以显著降低温度峰值,延后排盐时间可以略微降低峰值,此外采用三角形排布可以延缓局部凝固时间。研究结果可为EDS-PRHRS提供设计参考。[Background]Liquid molten salt reactor has many features such as high economy,safety and on-line fuel processing.The emergency draining salt passive residual heat removal system(EDS-PRHRS)is a unique residual heat removal system design for liquid fuel molten salt reactor,in which safely export residual heat of the molten salt in the salt draining tank is the first requirement for EDS-PRHRS design.[Purpose]This study aims to analyze the transient characteristics of EDS-PRHRS salt discharge tank during operation by simulation.[Methods]Firstly,the accident analysis of the passive residual heat removal system was carried out.The peak temperature of the molten salt was mainly found in the full heat discharge phase of the salt discharge tank.Then,a computational model of the molten salt coupled to the heat exchanger element was established for this stage of the discharge tank and numerical simulations were carried out by using computational fluid dynamics(CFD)analysis software Fluent.The Mixture model was used to simulate the boiling heat exchange of water in the heat exchanger element.Finally,different parameter sensitivity analysis scenarios were designed to investigate the effect on the transient.[Results]The analysis results show that the heat exchange power of the heat exchange element gradually decreases with time,and the temperatures of the outer wall and the hot spot of molten salt have a peak with time.[Conclusions]By increasing the axial height of the thimble and enhancing the emissivity of the air gap layer,the temperature peak can be significantly reduced,and the peak value can be slightly reduced by delaying the salt discharge time.In addition,the triangular arrangement of can delay the local solidification time.The study results can provide some reference for EDS-PRHRS design.

关 键 词：熔盐反应堆 余热排出系统 数值模拟 瞬态 敏感性分析 

分 类 号：TL426[核科学技术—核技术及应用] TL333