10K及以下温区，制冷机工质气体氦气的比热高于目前几乎已知的所有蓄冷材料，导致回热器蓄冷能力不足，成为制冷机在此温区性能提高的一个瓶颈问题。本项目开展使用多孔材料吸附部分工质气体氦气作为制冷机10K以下温区回热器的机理研究和实验测试。将在通过氦气吸附量大小对多孔材料进行测试筛选的基础上，混合搭配热导率具有明显差异的不同多孔材料，并组合丝网、纤维毡等低流阻填料，研制具有“高比热、各向异性热导率和低流阻”三大理想特征的高效回热器。同时，将基于质量、动量和能量守恒方程，结合气体状态方程和吸附/脱附速率的线性推动力方程进行编程计算，对交变流动下温度压力等存在明显相位差异这一特殊条件下的多孔材料对氦气的动态吸附/脱附特性以及多孔材料吸附/脱附热效应与制冷机微观制冷效应的耦合影响等基础问题开展研究。本项目是极低温回热器研究的一个新探索，可以为10K以下温区制冷机回热器材料的选择和使用提供有益的帮助。

The specific heat capacities of the working gas helium are much higher than that of the general regenerator materials with temperature below 10 K, which severely limits the enhancing of the refrigerator performance. The mechanical of regenerator using adsorbed helium by porous material with temperature below 10 K will be studied in this project. The porous materials were screened firstly by the amount of adsorbed helium, then the selected porous materials with a significant thermal conductivities difference and screens or fiber mats with a low flow resistance will be assembled to build a regenerator with characteristics of high heat capacity, anisotropic thermal conductivity and low flow resistance. Meanwhile, a calculation model based on the continuity equation, momentum equation, energy equation, gas state equation and adsorption/desorption rate linear driving force equation will be built to study the dynamic adsorption/desorption characteristics and the coupling effects of adsorption/desorption heat effect and refrigerator cooling effect by porous materials under the alternating flow conditions, where a significant phase difference between the temperature and pressure. This project provides a novel way for regenerator study, and it will be beneficial to the development of refrigerator with temperature below 10 K.