Regenerative cryogenic machine

Abstract

The application relates to a cryogenic machine of the regenerative type, comprising: a pressure oscillator, at least one cold finger ( 20 ) in fluid connection with the pressure oscillator, wherein the pressure oscillator comprises a centrifugal compressor ( 1 ) and a fluid distribution member ( 12 ) configured to alternately distribute high-pressure and low-pressure working fluid from the centrifugal compressor into said cold finger.

1 . A cryogenic machine of a regenerative type, comprising:
 a pressure oscillator,   at least one cold finger in fluid connection with the pressure oscillator,   wherein the pressure oscillator comprises a centrifugal compressor and a fluid distribution member configured to alternately distribute high-pressure and low-pressure working fluid from the centrifugal compressor into said cold finger.   
     
     
         2 . The cryogenic machine according to  claim 1 , wherein the compression ratio of the centrifugal compressor is between 1.1 and 1.5. 
     
     
         3 . The cryogenic machine according to  claim 1 , wherein the operating frequency of the pressure oscillator is greater than 10 Hz. 
     
     
         4 . The cryogenic machine according to  claim 1 , wherein the centrifugal compressor is arranged between a buffer tank called low-pressure buffer tank and a buffer tank called high-pressure buffer tank, the fluid distribution member being configured to selectively put in fluid connection the cold finger and one of the low-pressure and high-pressure buffer tanks. 
     
     
         5 . The cryogenic machine according to  claim 1 , wherein the fluid distribution member comprises a rotary valve or a linear distribution valve. 
     
     
         6 . The cryogenic machine according to  claim 1 , comprising a cold finger of a pulsed gas tube type including a pulse tube, an exchanger and a phase shifter. 
     
     
         7 . The cryogenic machine according to  claim 1 , comprising a cold finger of a Stirling type including an expansion piston. 
     
     
         8 . The cryogenic machine according to  claim 1 , wherein the fluid distribution member is configured to be fluidly actuated by the working fluid or mechanically by an outer actuator. 
     
     
         9 . The cryogenic machine according to  claim 7 , wherein the fluid distribution member is configured to be actuated by a control rod of the expansion piston of the cold finger. 
     
     
         10 . The cryogenic machine according to any of  claim 1 , containing helium as working fluid. 
     
     
         11 . The cryogenic machine according to  claim 1 , comprising several cold fingers, each cold finger being fluidly connected to one or several centrifugal compressors. 
     
     
         12 . The cryogenic machine according to  claim 4 , further comprising a circuit for circulating working fluid from the high-pressure buffer tank to the low-pressure buffer tank, so as to cool a part offset from the cold finger and mechanically decoupled from said cold finger. 
     
     
         13 . A spacecraft comprising a cryogenic machine according to  claim 1 .