Thermally driven pulse tube refrigerator
日本大學原子力研究所
@戴巍,周淑亮,松原洋一,小林久恭
Pulse tube refrigerator has no moving component at low temperature region, which makes it a good candidate for use in liquid helium temperature region. However, it’s hard to use helium4 to achieve temperature much below 4k due to its thermal property. Helium3 seems to be a good replacement of helium4 for this purpose. Actually, researchers in Holland have used helium3 in an ordinary three stage pulse tube refrigerator as working gas and obtained lowest temperature of 1.78K . However, because G-M compressor and reservoir hold large amount of gas and helium3 is very expensive, the total cost is very high. Besides, the existence of gas distribution valve and orifice makes the system efficiency low. In this article, a novel design for pulse tube refrigerator for the purpose of using helium3 is introduced, which eliminates the two shorreatcomings mentioned above. By using liquid nitrogen and one pulse tube refrigerator, a thermal compressor, which include one displacer, work transfer tube and regenerator, is constructed to generate the needed pressure wave. Then an expander is used at pulse tube hot end, which is aimed to generate cooling effect by absorbing work. Some preliminary experiment results and analysis are also given here.