Development of a compact cryocooler system for high temperature superconductor filter application

Abstract

Seeking a higher specific power of the pulse tube cryocooler is an important trend in recent studies. High frequency operation (100Hz and higher), combined with co-axial configuration, serve as a good option to meet this requirement. This paper introduces a high efficiency co-axial pulse tube cryocooler operating at around 100Hz. The whole system weighs 4.3kg (not including the radiator) with a nominal input power of 320W, namely, power density of the system is around 74W/kg. The envelop dimensions of the cold finger itself is about 84mm in length and 23mm in outer diameter. Firstly, numerical model for designing the system and some simulation results are briefly introduced. Distributions of pressure wave, the phase difference between the pressure wave and the volume flow rate and different energy flow are presented for a better understanding of the system. After this, some of the characterizing experimental results are presented. At an optimum working point, the cooling power at 80K reaches 16W with an input electric power of 300W, which leads to an efficiency of 15.5% of Carnot.