基于斯特林制冷机的磁体冷却系统实验研究  

Experimental study on a magnet cooling system based on Stirling cryocooler

作　　者：祁云 沈惬[1] 苏峙岳 乔鑫[1] 王泽铭 孙大明[1] Qi Yun;Shen Qie;Su Shiyue;Qiao Xin;Wang Zeming;Sun Daming(Institute of Refrigeration and Cryogenics,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学制冷与低温研究所,杭州310027

出　　处：《低温与超导》2022年第3期1-5,46,共6页Cryogenics and Superconductivity

基　　金：国家自然科学基金(51676168)资助。

摘　　要：为了减小磁共振成像低温超导磁体冷却过程中的液氮和液氦消耗,提高降温过程的可控性,提出基于千瓦级斯特林制冷机的氦气循环冷却系统,可将磁体快速冷却至液氮温度以下。对冷却系统建立数学物理模型并开展数值计算,在氦气平均压力为1.7 bar、流速为9.8 m/s时,系统冷却总重量为2 t的室温超导磁体至液氮温度仅需59.0 h。基于模拟结果开展实验研究,在相同条件下磁体实际降温时间为69.5 h,模拟计算与实验结果吻合良好。结果表明,该系统具备快速冷却超导磁体的能力,具有广阔的应用前景和深远的影响。In order to reduce the consumptions of liquid nitrogen and helium in the cooling process of the cryogenic superconducting magnets of the magnetic resonance imaging(MRI)and improve the controllability of the cooling process,a helium circulating cooling system based on a kW Stirling cryocooler was proposed,which could quickly cool the magnet below the liquid nitrogen temperature.The mathematical and physical model of the cooling system was built and numerical calculation was carried out.When the average pressure of helium is 1.7 bar and the flow rate is 9.8 m/s,it takes only 59.0 h for the system to cool the room temperature superconducting magnet with a total weight of 2 t to the liquid nitrogen temperature.Based on the simulation results,the experimental study was carried out.Under the same conditions,the actual cooling time of the magnet is 69.5 h.The simulation calculation is in good agreement with the experimental results.The results show that the system has the ability to quickly cool superconducting magnets,and has broad application prospects and far-reaching significance.

关 键 词：磁共振成像 超导 磁体冷却 斯特林制冷机 氦气循环 

分 类 号：TB651[一般工业技术—制冷工程]