Performance comparison of single-stage mixed-refrigerant Joule_Thomson cycle and reverse Brayton cycle for cooling 80 to 120 K temperature-distributed heat loads

[摘要] Thermodynamic performance comparison of single-stage mixed-refrigerant Joule-Thomson cycle (MJTR) and pure refrigerant reverse Brayton cycle (RBC) for cooling 80 to 120 K temperature-distributed heat loads was conducted in this paper. Nitrogen under various liquefaction pressures was employed as the heat load. The research was conducted under nonideal conditions by exergy analysis methods. Exergy efficiency and volumetric cooling capacity are two main evaluation parameters. Exergy loss distribution in each process of refrigeration cycle was also investigated. The exergy efficiency and volumetric cooling capacity of MJTR were obviously superior to RBC in 90 to 120 K temperature zone, but still inferior to RBC at 80 K. The performance degradation of MJTR was caused by two main reasons: The high fraction of neon resulted in large entropy generation and exergy loss in throttling process. Larger duty and WLMTD lead to larger exergy losses in recuperator.

[发布机构] Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing; 100190, China^1;University of Chinese Academy of Sciences, Beijing; 100049, China^2

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Evaluation parameters;Exergy loss distributions;Joule-thomson cycles;Performance comparison;Performance degradation;Temperature-distributed heat loads;Thermodynamic performance;Volumetric cooling capacities