新型液氦温区小型低温制冷机研究

随着科学技术的进步和新需求的出现，迫切需要发展高效紧凑的液氦温区小型低温制冷机。在此背景下本项目提出一种新型架构形式，采用VM型热压缩机驱动液氦温区脉冲管制冷机，利用高频斯特林型脉冲管制冷机提供VM热压缩机所需冷量，解决现有技术中存在的难点。针对新架构形式下的科学问题，项目着重研究（1）VM型热压缩机的高效能量转换特性及其与液氦温区脉冲管制冷机的高效耦合机制；（2）提供预冷冷量的高频斯特林型脉冲管制冷机与VM热压缩机系统的耦合机制研究；（3）液氦温区脉冲管制冷机损失机制和热端调相机构工作机理。在理论进展的同时，搭建实验样机获得4.2K以下温度。本项目的实施将为发展一种新型液氦温区低温制冷机打下坚实的基础。

With the advances of modern science and technology, more strict requirements are put on the size and efficiency of the cryocooler system working around liquid helium temperature. Here the applicant proposes a new infrastructure which aims at solving the difficulties faced by state-of-art technologies. In the infrastructure, a VM type thermal compressor is used to drive a pulse tube cooler to reach liquid helium temperature. Another high efficiency Stirling type pulse tube cooler is utilized to provide cooling power for the VM thermal compressor to establish the temperature gradienct necessary for the conversion of thermal power into acoustic power.The research focuses on the following three points: (1) High efficiency energy conversion mechanism of the thermal compressor and its coupling mechanism with the pulse tube cooler working at liquid helium temperature; (2) The coupling mechanism between the Stirling type pulse tube cooler and the VM thermal compressor; (3) Losses inside the pulse tube cooler working at liquid helium temperature and phase adjusters at the hot end of the pulse tube. With the theoretical development, a lab prototype system will be built and will reach temperature below 4.2 K. The project sets a solid basis for a new type cryocooler system working around liquid helium temperature.