液态锂锡合金中氚解吸行为的模拟

Simulation of Tritium Desorption Behavior from Liquid Lithium Tin Alloy

摘要:

液态锂锡合金是很有前途的聚变-裂变混合堆(FFHR)包层产氚材料。为完成FFHR包层氘-氚燃料循环系统的概念设计，以金属与氢的作用理论为基础，建立了液态Li25Sn75中氚解吸行为的动力学模型，模拟和分析了合金温度、氚分压、氦流量对解吸气中氚分压的影响以及氚在液态Li25Sn75中的传质系数、解吸率和吸附率。计算结果表明：在673~873 K的温度范围内，氚从液态Li25Sn75到气相的整个解吸过程，虽然包含了氚在熔融合金气泡中的扩散与对流、氚通过与气-液界面相连合金层的扩散、在界面发生的氚原子重组多相反应、氚通过气相边界层的扩散和气相中氚的扩散与对流5个子过程，但起决定作用的是氚在合金内的扩散和气-液界面的多相反应重组

Abstract:

The liquid lithium tin alloy is a promising breeder material for the tritium blanket of the fusion fission hybrid reactor (FFHR). For an effective design of the deuterium-tritium fuel circulation of FFHR, a mathematical model of kinetics of tritium desorption behavior from liquid Li25Sn75 alloy was built based on the action theory of metals and hydrogen. The calculation data of tritium desorption behavior under different operating conditions of temperature, tritium partial pressures, helium gas flow and mass transfer coefficients were obtained. The results show that the overall desorption process, even though including five sub-processes (transport of the tritium by diffusion and convection, transport of the tritium by diffusion through a layer of eutectic adjacent to the gas-eutectic interface, heterogeneous reaction at the interface of the tritium atoms recombination, diffusion of the tritium through the gas-phase boundary layer and transport of the gaseous tritium by diffusion and convection from the gas phase boundary layer), is governed by the diffusion of tritium atoms in the Li25Sn75 and by the heterogeneous reaction at the gas-eutectic interface of the tritium atoms recombination in the desorption temperature range from 673 to 873 K