空间液氦温区J-T节流制冷机节流微孔实验  

Experimental research on the J-T orifice of a space 4.5 K hybrid J-T cooler

作　　者：马跃学 王娟[1] 刘彦杰[1] 李建国[1] 梁惊涛[1] Yuexue Ma;Juan Wang;Yanjie Liu;Jianguo Li;Jingtao Liang(Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China)

机构地区：[1]中国科学院理化技术研究所,北京100190

出　　处：《科学通报》2018年第18期1839-1846,共8页Chinese Science Bulletin

基　　金：国家自然科学基金(51776213);国家重点基础研究发展计划(613322)资助

摘　　要：液氦温区节流制冷机在空间探测中获得了广泛的应用,基于本实验室研制的多级高频脉冲管预冷节流循环的复合式制冷机,针对节流微孔对节流制冷机性能的影响进行分析和实验.研究发现,节流微孔的尺寸不仅影响节流制冷机的流量,对节流制冷效果也有着重要影响.通过实验对不同孔径微孔进行了研究,获得了最佳微孔尺寸.此外,对节流前高压对节流制冷机流量、制冷机和最低无负荷温度的影响进行了分析和实验研究.基于此,采用三级无油线性压缩机驱动节流循环,测试了闭式循环节流制冷机的性能,在4.48 K获得了81.5 m W的制冷量.Hybrid J-T cryocooler is commonly employed in space detective missions requiring liquid helium temperature. In fact, nearly all the space applications of mechanical cryocoolers working at 4.5 K, having been launched or under development are hybrid J-T cryocoolers. For instance, mechanical cryocoolers used in Planck, JWST, SMILES, SPICA and so on, are all hybrid J-T cryocoolers. However, there is hardly any research on space 4.5 K hybrid J-T cryocooler in China. Key laboratory of space energy conversion technologies in Technical Institute of Physics and Chemistry（TIPC）, Chinese Academy of Sciences（CAS） has developed a 4.5 K J-T cooler precooled by two-stage pulse tube cryocooler. Base on this cryocooler, the influence of supply pressure and diameter of the J-T orifice on the cooling capacity of the J-T cooler is analyzed and experimentally studied. First of all, the influence of supply pressure and diameter of the J-T orifice is theoretically calculated. Then, experimental research is carried out. For the purpose of shortening experimental time, a two-stage GM cooler instead of pulse tube cooler is used to precool the J-T cycle. Firstly, open loop experiments are conducted because it＇s much easier to adjust the supply pressure precisely. The mass flow rate of the J-T cooler rises monotonously as diameter of the J-T orifice decreases. However, the cooling capacity of the J-T cooler goes through an up and down process because the J-T effect turns to be worse when diameter of the J-T orifice increases. That is to say, performance of the J-T cooler turns to be worse when the diameter of the J-T orifice is larger than 34 μm. Based on the research of this paper, 34 μm J-T orifice may be the best choice of the hybrid J-T cooler. Besides, both mass flow rate and cooling power increase as supply pressure increases when supply pressure is below 2.0 MPa. In addition, the no load temperature of the J-T cooler rises with increasing supply pressure which is attributed to the flow resistance of the counter-flow heat

关 键 词：空间 4.5 K J-T制冷机 线性压缩机 节流微孔 

分 类 号：TB651[一般工业技术—制冷工程]