Design and Experimental Verification of a Large Cooling Capacity GM Cryocooler with Detachable Structure

In the cryogenic system of high temperature superconducting cable,detachable structure was used to meet the replacement and maintenance of GM cryocooler when the cryogenic system continues operating.In order to improve the heat transfer performance of the system and reduce the temperature difference at the low temperature in vacuum,the cryogenic system with detachable structure was designed and the heat leakage was analyzed.The change of the heat transfer temperature difference has been studied with the different cold temperature and pre-tightening torque.The heat transfer performance of adding indium foils between the connection surfaces was investigated.The experimental results show that the heat transfer temperature difference decreases gradually with the increase of the preload torque when the heat load is 255 W@70 K.And the temperature difference is only 0.82 K when the torque is 10 N·m.When the pre-tightening torque is small,the addition of indium sheet has a relatively strong effect on reducing the heat transfer temperature diffe-rence,while the effect of indium sheet thickness is relatively small.