钯银合金膜可用于熔盐堆尾气中气态氚(HT和T2)的分离与纯化.本文研究了厚度为80 μm的钯银合金膜在纯H2气氛中及Ar气存在下对H2的分离效果.结果表明,渗氢过程中氢原子在膜内部的体相扩散是控制速率的关键.Ar气存在时,在钯银合金膜工作温度为480 ℃、混合气体进气流速为100 mL/min、氢分压差为20～100 kPa的条件下,钯银合金膜对H2气的渗透通量随氢分压差的增大而增加,随Ar气浓度的升高而减小.在氢分压差相同的条件下,纯氢的渗透通量明显高于Ar-H2混合气的渗透通量,说明钯银合金膜受Ar气的影响分离效果变差.渗氢后的钯银合金膜表面变得光滑,有晶界形成.%Pd/Ag alloy membrane can be used to separate and purify HT/T2 from the offgas of TMSR.In this paper,a Pd/Ag alloy membrane with thick of 80 μm was chosen to separate H2,which can simulate the separation of tritium.The separation effect of Pd/Ag alloy membrane in pure H2 and H2-Ar gas mixture was studied.The results indicate that the diffusion of atomic hydrogen through a membrane is the controlling mechanism and rate determine step of hydrogen permeation.In the condition of H2-Ar gas mixture,the H2 permeation flux reduces remarkably due to the influence of concentration polarization of Ar.Through the analysis of the membrane surface under SEM,the ratio of Pd in the alloy membrane increases and the grain boundary can be found,which could be inferred to the influence of H2 permeation.
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