Study On High Frequency(300Hz) Pulse Tube Cryocoolers

The pulse tube cooler has developed in recent years, while the super high frequency pulse tube cooler is scarce. The main reason is lack of compressors with frequency of designed above 70Hz.In these years, with the development of thermoa- coustical engine, we have an idea of using thermoacoustical engine instead of mechanical compressor driving pulse tube cooler, and the system has no moving parts at all. In this paper, we have focus on 300Hz pulse tube cooler, the regenerator and phase shifter are investigated theoretically and experimentally.1. Experimental and theoretically study on regenerator of 300Hz pulse tube cooler has been done. Analysis of the heat transfer on single stainless steel wire of screen, and the characteristic of the thread under various frequency for different material and size has been revealed. Considering heat transfer and thermal penetration depth, the 635# stainless steel screen is a better choice, which can be approved in the experimental results.2. A 300Hz pulse tube cooler has been designed. Experimental study was carried out to investigate the function of the phase shifter, pressure charge and the size of regenerator to the performance of the pulse tube cooler. A lowest temperature of 79.7K has been achieved in the linear pulse tube cooler. It can afford the cooling power of 1W at 120K. For the coaxial pulse tube cooler, a phenomenon of unsteady temperature was found when the size of inertance tube was large in diameter.3. The working mechanism of inertance tube was studied. Relied on a linear network model of inertance tube which is built by simplifying the equations of fluid mechanics. The characteristic of the inertance tube with different sizes at 300Hz or more was analyzed.4. High frequency multi-bypass pulse tube cooler was set up, various bypass coupling with inertance tube and double inlet was used as the phase shifter. By improving and optimizing the structure, a cold end temperature of 23.1K was gained and cooling capacity of 0.6W at 35K was obtained.