【摘要】 液态铅铋合金(Liquid Lead-Bismuth alloy,LBE)是第4代液态金属冷却反应堆首选的冷却剂材料,但面临氧浓度降低困难的问题,理论上通过氢化锂与氧反应可以降低其中的氧浓度,然而反应产物不溶性微小颗粒物氧化锂会威胁反应堆的安全运行。以铅铋合金系统的膨胀箱为研究对象,利用fluent软件对圆柱形箱体内固态颗粒物运动进行分析和模拟,连续相采用标准k-ε模型,固相颗粒物采用离散相模型(Discrete Phase Model,DPM),研究铅铋合金中氧化锂颗粒物的运动规律。结果显示:大直径的氧化锂颗粒上浮时间短,在径向方向的位移小,导致靠近轴心的浓度较高,小直径的氧化锂颗粒上浮时间长,在径向方向的位移大,导致靠近轴心的浓度较低。为后续铅铋合金系统的净化与控制提供参考。更多还原

【Abstract】 [Background] Liquid lead-bismuth alloy(LBE) is the preferred coolant material for the 4 th generation liquid metal cooled fast reactor, but it is difficult to reduce the oxygen concentration. Theoretically, the oxygen concentration can be reduced by the reaction of hydride with oxygen. However, the reaction product insoluble microparticles will threaten the safe operation of the reactor. [Purpose] This study aims at the floating law of particles in liquid lead-bismuth alloy that has significant reference for the collection of impurities and the purification of lead-bismuth alloy. [Methods] The fluent software was used to analyze and simulate the movement of solid particles in a cylindrical box. The standard k-ε model was adopted for continuous phase whilst the discrete phase model(DPM) was used for solid phase particulate matter to study the movement of particles in lead-bismuth alloy.[Results & Conclusion] The distribution of the large diameter particles is close to the axial center of the cylinder,and the distribution of the small diameter particles is farther from the axial position than that of the larger particles.The particles with large diameter have a short floating time, the particles with small diameters have a long floating time, and the temperature has little influence on the floating time and can be ignored. With a radius of about 90 mm around the central axis, the concentration of the particles is 2～3 times higher than that of other positions. Therefore,the attention should be paid to this range when purifying the lead-bismuth alloy, and the efficiency and effect of purification are good.更多还原