【摘要】 低温制冷机是液氢长期在轨零蒸发贮存的关键技术之一。节流制冷机无低温运动部件,具备系统简单和可连续制冷等优点。本文提出了液氢温区直接节流制冷新流程,拟采用回热式制冷机或者液氢储罐排气冷量为其提供32 K以下的预冷量,有潜力实现快速降温和高效制冷。采用热力学方法对于给定液氢温区10 W的制冷量要求,以等温压缩功为优化目标对该制冷机进行优化。分析得到了优化等温压缩功及其对应的优化高压压力和预冷量与预冷温度之间的变化关系。结果表明:当预冷温度低于32 K时,直接节流制冷机在优化工况下运行时与典型节流制冷机性能接近,但其结构得到简化,稳定性高且制冷机降温初期无需旁通。更多还原

【Abstract】 Cryocooler is one of key technologies for zero-boil-off storage of liquid hydrogen in space. The throttling cryocooler with no moving parts at low temperature has the advantages of systematic simplicity and continuous refrigeration. A novel direct throttling cryocooler process applied for liquid hydrogen temperature is proposed. It has the potential to achieve the rapid and efficient cooling while the regenerative cryocooler or exhaust gas from liquid hydrogen storage tank could be adopted for its precooling below 32 K. To achieve the cooling capacity requirement of 10 W at liquid hydrogen temperature,the cryocooler is optimized taking the isothermal compression work as the optimization objective by thermodynamic method. The optimized isothermal compression work together with the corresponding high pressure and required precooling capacity are obtained as functions of the precooling temperature. The results show that when the precooling temperature is lower than 32 K,the performance of the direct throttling cryocooler is close to the typical throttling cryocooler. Meanwhile,the structure of the cryocooler is simplified with higher stability. The by-pass process is no longer required during the cool-down period.更多还原