过冷态超流氦恒温器的热力学分析

摘要

对过冷态超流氦恒温器的热力学过程进行分析,考察了不同的设计温度和J-T换热器热效率下恒温器的制冷性能,得到了理论制冷量的变化曲线.结果表明,理论制冷量与设计温度和J-T换热器的热效率密切相关.计算发现,160 L液氦在2W制冷量下从4.2K降至1.8K大约需要24 h.%Thermodynamic analysis of subcooled superfluid helium cryostat was carried out.The influence of different design temperature and different efficiency of J-T heat exchanger on theoretical cooling capacity was analyzed,and theoretical cooling capacity variation curves were also presented.The results show that theoretical cooling capacity is greatly related to design temperature and efficiency of J-T heat exchanger.It will take about 24 h to cool 160 L liquid helium from 4.2 K down to 1.8 K with 2 W cooling capacity.