Performances investigation of two parallel PTCs driven by one linear compressor

To achieve refrigeration at different positions, we tried out pairs of different coaxial pulse tube cryocoolers (PTCs) driven in parallel by a single compressor and set up an experimental apparatus. The refrigerating performances of different PTC combinations are investigated through simulation and experiments. The distribution of output PV power between the PTCs is analysed by comparing the refrigeration performance for single PTC operation to that of two PTCs operated in parallel. Experiments and simulation results show that a typical combination consisting of PTC1 (diameter of cold finger: 14 mm) and PTC2-1 (diameter of cold finger: 10 mm) can simultaneously achieve refrigeration capacities of around 0.5 W at 60 K and 0.5 W at 80 K. The combination of two samples (PTC2-1 + PTC2-2) of the same type of PTC shows a non-uniformity of refrigerating performances. Power distribution among the PTCs depends mainly on the size of the pulse tubes and the phase change. The length of the connection tube has significant influence on the refrigeration performances of two parallel PTCs in the experiments.