氢仲-正转化释冷方案及冷量空间利用潜能分析

调研了氢仲-正转化释冷能力及研究现状，介绍了绝热、连续、等温三种转化方式的释冷潜能与工作特征。针对氢空间长期安全贮存，按照转化器布置位置与转化方式，提出四种冷量空间利用方案。研究发现：氢绝热转化在150 K时释冷量最大，为391 kJ/kg；等温转化在110 K时释冷量最大，为394 kJ/kg；连续转化在出口温度大于200 K后，释冷量稳定在491 kJ/kg。所提四种方案中，由于空间排气温度偏低，造成氢仲-正转化潜能无法充分释放，对贮箱绝热性能提升有限。相较于一次绝热转化，在蒸气冷却盘管内连续转化可较充分利用转化冷能，在氢的空间贮存应优先考虑。

Analysis on Cold Energy Release Schemes in Para Ortho Hydrogen Conversion and Its Utilization Potential in Space

The research status and cooling capacity of the para-ortho hydrogen conversion are investigated, and the cooling potentials and characteristics of three conversion strategies, including adiabatic conversion, isothermal conversion, and continuous conversion, are introduced successively. To serve the long-term on-orbit hydrogen storage, considering the converter position and conversion strategies, four utilization schemes of the para-ortho hydrogen conversion are proposed. Several conclusions may be drawn as follows: in an adiabatic conversion, a hydrogen flow with the temperature of 150 K has the maximum cold energy release of 391 kJ/kg; in an isothermal conversion, the maximum energy release could reach at the temperature of 110 K with a value of 394 kJ/kg; in a continuous conversion operation, an approximately steady energy release of 491 kJ/kg is obtained after the outlet temperature is larger than 200 K. Moreover, due to the low discharged gas temperature of the hydrogen tank, the para-ortho hydrogen conversion capacity could not be fully utilized and the insulation level of the hydrogen tank also could not be improved apparently. Comparatively, the continuous conversion in cooling shield has a better utilization of the conversion energy and is suggested in the future.