AI 中文总结
针对金属/熔盐界面化学势连续性假设失效问题，提出基于可逆反应通道的动力学界面模型，在festim中实现，可泛化LTE，在镍/FLiBe体系中能更准确预测氢同位素输运的渗透通量与压力指数。
AI 中文摘要
宏观氢输运代码采用局域热力学平衡（LTE）模拟材料界面，将化学势连续性作为各物种的约束条件，该条件隐含三个假设：界面平衡快速达成、两侧仅存在单一交换路径、两侧载流物种已预先明确。已有研究主要关注第一个假设的失效，而另外两个假设的失效影响更为显著，且在金属/熔盐界面处均不成立。本文用遵循质量作用定律的界面可逆反应通道替代原约束，通过详细平衡从已参数化LTE的热力学数据中确定各速率常数的比值，并在festim框架中实现该方法。当反应通道的动力学足够快时，该框架可恢复LTE的Sieverts/Sieverts和Sieverts/Henry形式，因此该框架是LTE的泛化而非与之竞争。达姆科勒数限定了单一通道内的有效性，通道间的分支比则决定多通道情形。在典型的镍/FLiBe体系中，氢会在分子载流子与氟化物载流子之间发生动力学分配，此时表观界面定律会随氢负载量和盐的氧化还原状态在Sieverts定律与Henry定律之间漂移，而LTE条件会低估稳态渗透通量；测得的压力指数由分支比而非盐的固有属性决定，固定温度下的氧化还原扫描可使该指数在0.5至1之间连续变化。若存在两种同位素，金属侧的两种物种会供给盐侧的五种载流子，此时各物种的LTE条件是不适定的。
英文摘要
Macroscopic hydrogen transport codes model material interfaces with local thermodynamic equilibrium (LTE), imposing continuity of chemical potential as a per-species constraint. Three assumptions hide in that condition: fast interfacial equilibration, a single exchange pathway between the two sides, and a carrier species known in advance on each side. The literature scrutinises the first, but the other two are the more consequential failures, and neither survives at a metal/molten-salt interface. We replace the constraint with reversible reaction channels at the interface that obey mass action, with detailed balance fixing each ratio of rate constants from the thermodynamic data that already parameterise LTE, and we implement the framework in festim. LTE is recovered as the fast-kinetics limit of a single channel, in both its Sieverts/Sieverts and its Sieverts/Henry form, so the framework generalises LTE and does not compete with it. A Damköhler number delimits validity within a channel, a branching ratio between channels. In a representative nickel/FLiBe system, hydrogen partitions kinetically between molecular and fluoride carriers. The apparent interfacial law then drifts between Sieverts and Henry with loading and salt redox state, and an LTE condition underestimates the steady permeating flux. The measured pressure exponent is set by the branching ratio, not by any fixed property of the salt; a redox sweep at fixed temperature should continuously shift it between 0.5 and 1. With two isotopes, two metal-side species feed five salt-side carriers, and a per-species LTE condition is ill-posed.
