A thermoacoustically driven pulse tube refrigerator capable of working below 120 K

Based on the discussion of the matching problems between the prime mover an d pulse tube, a self-made standing-wave thermoacoustic prime mover is used to drive a coaxial single-stage pulse tube refrigerator. A lowest refrigera tion temperature of 138 K was obtained from the preliminary tests in 1999. Then, some improvements have been made to the heat exchangers and the conne ction between prime mover and pulse tube. The minimum cooling temperatures of 119.7 and 117.6 K have been obtained from the recent experiments with he lium and helium-argon mixture filling of 2.0 MPa as the working fluids, res pectively. It is a great progress for the standing-wave machine and provide s the possibility of liquefying natural gas of 0.2 MPa. (C) 2001 Elsevier S cience Ltd. All rights reserved.