| The cryoelectronics are based on reducing the thermal noise dynamic resistantance of the conductor, including semiconductor circuits, high-temperature superconducting circuits, semiconductors and superconductors hybrid integrated circuits, optoelectronic circuits, with the main district temperature from 60K to 80 K and 1 ~ 6 W cooling power.Based on the collaboration with SITP (Shanghai Institute of Technical Physics), CAS (Chinese Academy of Sciences), this thesis focused on the Stirling-type co-axial pulse tube cryocooler for space application, a high capacity prototype is developed, and the main contents of this paper are given as follows:1. Based on the calculation of the regenerator by REGEN3.3, the exergy analysis has been conducted. The influences of phase angle between the mass flow and pressure wave at cold end on the exergy efficiency under different pressure ratios have been compared. In addition, the effects of the pressure and thermal contributions on the exergy at cold end of regenerator have also been compared. The results show that the pressure component dominates the amount of exergy available. For a regenerator with specified sizes, the exergy efficiency reaches the maximum when the pressure ratio is 1.2 and the phase angle bewteen the mass flow and the pressure wave at cold end is -30°.2. The key components of the coaxial pulse tube cooler have been designed and improved in detail. The plug part of the regenerator has been improved, and thus having a higher performance. A novel thread welded integral cold finger has been designed. Three special structures have been used to optimize the performance of the cold end: The welding with the screw joint increase the reliability of welding and the security of leak detection; the slit-type flow channels not only make the working flow more uniform but also increase the overall heat transfer area of the cold end; the copper screen in center hole of annular baffle straightens the flow into the pulse tube and plays a role of heat exchanger.3. The experimental setup of miniature Stirling-type coaxial pulse tube cryocooler has been built up. The cold end temperature of the pulse tube cryocooler has been measured using platinum resistance thermometer. With heat balance method the cooling capacity for the pulse tube cryocooler at a certain temperature has been achieved. On the other hand, dynamic measurement has been achieved with data acquisition by the computer.4. Experimental test and analysis on coaxial pulse tube cryocoolers has been carried out. Firstly, the influence of the inertance tube on the performance of pulse tube cryocooler was studied. The experimental results showed that, the pulse tube cryocooler has different performances the different groups of inertance tubes. For a fixed group, the optimal cooling performance of the co-axial PTC is achieved at an operating frequency. However, the variation of the lowest temperature is no more than 2K over the range of 4Hz of the optimal frequency. Secondly, based on study of the prototype CPTC8001, a prototype CPTC8002 with a novel integral cold finger has been designed,fabricated and tested. The CPTC8002 achieved 4W cooling power at 80 K with electrical input power 134W. Finally, the reason why the prototype CPTC8002 cannot reach the goal has been analyzed.
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