微热复合吸氢剂在高真空多层绝热储罐中的实验研究

Adsorption Behavior of Novel Composite H_2-Getter in High Vacuum Multilayer Insulated Cryogenic Tank

氢气是造成高真空多层绝热储罐夹层真空度下降的主要原因,为此本文搭建了吸氢试验台,研究了廉价微热型吸氢剂CuO+C,在夹层氢气压力较高时,不同吸附温度下的吸氢特性;比较了吸附温度在100℃时,CuO+C和CuO+C+5A的不同吸氢特性;探索了CuO+C+5A吸附氢气达到平衡,充注液氮后,夹层压力随时间的变化;研究表明:复合吸氢剂是化学吸附氢气,最低活化温度为60%,吸附诱导期随着吸附温度的升高,由长变短,在160℃时消失;在高真空多层绝热储罐的内罐外壁底部放置5A分子筛后,平衡压力由220变为8.4 Pa,而达到平衡所需要的时间仅增加了60 h;平衡后向储罐充注液氮,夹层压力随时间成阶梯型变化,经过10 h,夹层真空度达到5.83×10^(-4)Pa,完全满足高真空绝热的使用要求。

The adsorption behavior of the novel micro-thermo composite hydrogen getter, CuO ＋ C powders and 5A molecular sieve of CuO ＋ C for the high vacuum muhilayer insulated cryogenic tank, was characterized with the lab-built test platform. The influence of the adsorption conditions, including the adsorption temperature and cooling time of liquid nitrogen （LN2）,on the pressure in the vacuum layers of cryogenic tank was investigated. The results show that the novel low-cost adsorbent is a good getter of residual gases, particularly H2. For example, chemisorption of H2 accounts for the getteringmechanism, with the lowest activation temperature of 60℃ ;as the adsorption temperature increased, the activated period decreased,vanishing at 160℃ ;the 5A CuO ＋ C reduced the equilibrium pressure from 220 to 8.4 Pa and increased the exhaustion time by 60 h. Filling of LN2 reduced the pressure in an irregularly stepped manner, corresponding to the stages of tank-cooling,getter-cooling and residual gas-adsorption,to a pressure to 5.83 × 10……-4 Pa after 10 h.