TY  - EJOU
AU  - Wang, Qi 
AU  - Han, Dongxu 
AU  - Gao, Bo 
AU  - Liu, Siqi 
AU  - Zhang, Haiyang 
AU  - Wang, Peng 
AU  - Sun, Dongliang 
AU  - Yu, Bo 

TI  - Numerical Simulation Research on the Entire Process of a Cryostat Based on J-T Refrigeration Machine
T2  - The International Conference on Computational \& Experimental Engineering and Sciences

PY  - 2024
VL  - 29
IS  - 4
SN  - 1933-2815

AB  - The pre-cooled J-T refrigerator is an important device for achieving low temperatures in the 2K temperature zone through mechanical refrigeration. It provides a stable and reliable low-temperature environment in the 2K-5K temperature range and ensures the accuracy of the low-temperature thermostat in the reference temperature measuring device. In this paper, the SAGE model and ESS model were established to determine the cooling capacity at 2K using the pre-cooling J-T cycle of a two-stage G-M refrigerator, which is utilized in the low-temperature thermostat of a 2-5K reference temperature measuring device. Thermodynamic analysis of the J-T throttling process was conducted, and experimental data from the literature were employed to validate the models. Using this model, key operating parameters such as the high-pressure pressure (<i>P<sub>H</sub></i>) and pre-cooling temperature (<i>T<sub>pre</sub></i>) in the J-T cycle are analyzed and optimized. The results of the J-T refrigerator cycle were integrated with the low-temperature thermostat, and the cooling process and stability of the entire low-temperature thermostat system were simulated. It is found that when the final pre-cooling temperature <i>T<sub>pre</sub></i> remains constant, the cooling capacity <i>Q<sub>c</sub></i> first increases and then decreases with the high pressure PH. To meet specific cooling capacity requirements, optimal values for the final pre-cooling temperature <i>T<sub>pre</sub></i> and high pressure PH can be chosen to minimize the total power consumption of the J-T refrigerator. Considering the lower cooling temperature of the cryostat, the J-T refrigerator is capable of providing an 11mW cooling capacity for the cryostat at 2.2K, with a minimum no-load temperature reaching 2.13K. These research findings offer optimization strategies and theoretical insights for the refrigeration cycle process of the low-temperature thermostat in the reference temperature measuring device.
KW  - Cryostat; J-T refrigerator; pre-cooling temperature

DO  - 10.32604/icces.2024.012509