摘要
熔盐堆凭借其熔盐冷却剂在常压、高温环境下的卓越物理与化学性能,展现出较高的固有安全性和经济潜力。然而,熔融无机盐的凝固点较高,管内流动过程中若遇到冷点,可能导致管道冻结堵塞的风险。本研究采用商用计算流体力学(Computational Fluid Dynamics,CFD)程序ANSYA Fluent对熔盐填充冷管过程进行数值模拟,利用焓-孔隙率模型处理凝固相变问题,其中,糊状区常数(A_(mush))是重要影响参数之一。研究首先聚焦于熔盐冷管流动过程中的基本相界面结构、凝固与熔化现象等特性;随后,针对管道冻堵问题,分析了不同糊状区常数取值(5×10^(3)~5×10^(5))下的瞬态过程,计算得到一组堵塞穿透距离模拟值,并对其敏感性进行了探讨;最终,基于已有堵塞穿透距离实验值反推发现A_(mush)=5×10^(4)适用于HTS盐的糊状区效应估计。研究结果表明,糊状区常数对凝固相变特性具有显著影响,在使用焓-孔隙率模型时,正确选择糊状区常数对于准确预测介质固液相变行为及其冻堵特性至关重要。
[Background]Molten salt reactor is a promising type of reactor with excellent safety and economy,benefiting from the stable properties of its molten salt coolant at high temperatures.However,the freezing point of molten inorganic salt is usually high enough to pose a risk of coolant freezing,which could plug the pipelines when flowing through a relatively cold place.[Purpose]This study aims to present the process of the molten salt filling cold pipe with solidification-melting behaviors and estimate the mushy zone effect of molten salt with temperature near the freezing point.[Methods]The commercial CFD(Computational Fluid Dynamics)code ANSYS Fluent was used to numerically simulate the process,and the solidification-melting behaviors were solved by the enthalpy-porosity model,in which the mushy zone constant(A_(mush))was an important influencing parameter.By monitoring the velocity change of the characteristic interface,a set of penetration distances was simulated at different A_(mush) values(5×10^(3)~5×10^(5)),and an existing experiment was used to deduce the mushy zone constant for molten salt.[Results]Simulation results show that penetration distance is sensitive to variations in the mushy zone constant.Based on the existing experimental value of penetration distance,A_(mush)=5×10^(4) is suitable to mushy zone influence estimation for molten salt.[Conclusions]Based on the method proposed in this study for determining the mushy zone constant,proper selection of mushy zone constant is very much necessary to accurately solidification-melting process prediction when using the enthalpy-porosity model whilst the freezing point of molten inorganic salt is usually high enough presenting a risk of coolant freezing which could plug pipelines when flowing through relative cold place.
作者
于鸿翔
周翀
袁晓凤
陈玉爽
YU Hongxiang;ZHOU Chong;YUAN Xiaofeng;CHEN Yushuang(Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《核技术》
北大核心
2025年第7期263-274,共12页
Nuclear Techniques
基金
中国科学院上海应用物理研究所堆芯模块化理论与比选研究(No.SINAP-QYJS-202202)
甘肃省科技重大专项钍基熔盐堆关键装备与技术开发(No.23ZDGH001)资助。
关键词
熔盐
凝固与熔化
糊状区常数
堵塞穿透距离
计算流体力学
Molten salt
Solidification-melting
Mushy zone constant
Penetration distance
Computational fluid dynamics(CFD)
