锂铅液态金属电池自然对流瞬态分析

Transient analysis of natural convection in lithium-lead liquid metal battery

液态金属电池内部自然对流导致的界面波动会影响电池安全运行。采用数值模拟方法对锂铅液态金属电池(Li|LiCl|Pb)的自然对流过程进行分析,研究了绝热条件下不同电流密度和不同电解质层厚度时自然对流过程中温度场和流场的分布规律。结果表明:自然对流随电流密度的增大而增强,但受电解质厚度变化的影响却较小;放电初期,电池内温差和流速均迅速增大,随后温差趋于稳定并有下降的趋势,流速增长也逐渐平稳;由于本电池模型的正极区域液态金属的对流较弱,因此内部反应物混合过程不会明显影响电池性能。

Based on Li|LiCl|Pb battery, the natural convection, a key influence factor for operation security, was analyzed using a computational fluid software in different current density and thickness of molten salt. The results show that natural convection is enhanced with the growth of current density, rather than the thickness of electrolyte.The temperature difference increases sharply in the initial phase, then becomes stable and drops gradually. Flow velocity is the same at the beginning, and still increasing but much more slowly subsequently. Besides, the liquid metal in positive field flows very slowly, therefore the mixture effect does not have a notable influence to this model.