Patent ID: 6629418
Filing Date: 2003-10-07
Classification: F25B

Abstract:
A two-stage pulse tube refrigerator characterized by increased efficiencies and more compact design, comprisinga first stage pulse tube a first stage regenerator; a second stage pulse tube; a second stage regenerator; a compressor; high pressure piping connecting the high-pressure end of the compressor to the hot ends of the regenerators of both stages; low pressure piping connecting the low-pressure end of the compressor to the hot ends of the regenerators of both stages; piping connecting the cold end of the first stage pulse tube to the cold end of the first stage regenerator; piping connecting the cold end of the second stage pulse tube to the cold end of the second stage regenerator; four active valves disposed along the piping between the compressor and the hot ends of the regenerators that cycle in pairs between on and off positions effectively achieving the desired gas pressure-gas displacement that is 180 degrees out of phase within the two pulse tubes; a buffer tank connected by a bypass channel to the hot end of the first stage pulse tube and to the hot end of the second stage pulse tube; and an inter-phasing mechanism selected from active inter-phasing mechanisms and passive inter-phasing mechanisms including two valves, one in each of the lines between the hot ends of the pulse tubes and a buffer tank.