Cryogenic pumping system and innovative integration for sub-kelvin cryogenics below 1.5k

Abstract

A refrigeration device comprising a first working circuit for circulating a first working fluid, the first working circuit comprising the following elements connected in series by a first network of lines: a first compressor; a cooling unit; a third heat exchanger; a first Joule-Thomson expansion device; a first tank configured to be in heat exchange with an object to be cooled; the refrigeration device also comprising a thermally insulated enclosure and the first working circuit comprises a first pumping member connected to the first network of lines.

1 - 17 . (canceled) 
     
     
         18 . A refrigeration device comprising a first working circuit for circulating a first working fluid, the first working circuit comprising the following elements connected in series by a first network of lines:
 a first transfer member for the working fluid;   a cooling unit comprising a first heat exchanger comprising a first hot channel and a first cold channel that are connected to the first working circuit, the cooling unit also comprising a second heat exchanger comprising a second hot channel connected to the first working circuit and a second cold channel connected to a first cold source;   a third heat exchanger comprising a third hot channel and a third cold channel;   a first Joule-Thomson expansion device;   a first tank configured to be in heat exchange with an object to be cooled; and   a thermally insulated enclosure inside which at least some of the elements are located,   wherein the first transfer member is situated outside the enclosure,   wherein the first working circuit comprises a first pumping member situated inside the enclosure and connected to the first network of lines.   
     
     
         19 . The refrigeration device as claimed in  claim 18 , wherein the first network of lines is configured to connect:
 a first outlet of the transfer member, from which first outlet the first working fluid is delivered, to a first inlet of the first hot channel;   a second outlet of the first hot channel to a second inlet of the second hot channel;   a third outlet of the hot channel to a third inlet of the third hot channel;   a fourth outlet of the third hot channel to a fourth inlet of the first expansion device;   a fifth outlet of the first expansion device to a fifth inlet of the first tank;   a sixth outlet of the first tank to a sixth inlet of the third cold channel;   a seventh outlet of the third cold channel to an eighth inlet of the first transfer member, through which eighth inlet the first working fluid is drawn;   the first pumping member being situated between the sixth outlet and the eighth inlet.   
     
     
         20 . The refrigeration device as claimed in  claim 19 , wherein the first pumping member is connected directly to the eighth inlet. 
     
     
         21 . The refrigeration device as claimed in  claim 18 , the first pumping member is situated downstream of the seventh outlet. 
     
     
         22 . The refrigeration device as claimed in  claim 19 , further comprising a second Joule-Thomson expansion device and a second tank, the second expansion device comprising a tenth inlet in fluidic communication with the first circuit downstream of the third outlet and a tenth outlet in fluidic communication with an eleventh inlet of the second tank, the second tank comprising an eleventh outlet in fluidic communication with the eighth inlet, the second tank also comprising a first offtake for working fluid in liquid phase in fluidic communication with the first circuit upstream of the third inlet. 
     
     
         23 . The refrigeration device as claimed in  claim 19 , further comprising a third Joule-Thomson expansion device, a third tank and a fifth heat exchanger comprising a fifth hot channel and a fifth cold channel, the third expansion device comprising a twelfth inlet in fluidic communication with the first circuit downstream of the third outlet and a twelfth outlet in fluidic communication with a thirteenth inlet of the third tank, the third tank comprising a thirteenth outlet in fluidic communication with the eighth inlet, the third tank also comprising a second offtake for working fluid in liquid phase in fluidic communication with a fourteenth inlet of the fifth hot channel, a fourteenth outlet of the fifth hot channel being in fluidic communication with the first circuit upstream of the third inlet, a fifteenth inlet and a fifteenth outlet of the fifth cold channel being in fluidic communication with the first circuit downstream of the seventh outlet. 
     
     
         24 . The refrigeration device as claimed in  claim 19 , further comprising a sixth heat exchanger comprising a sixth hot channel and a sixth cold channel, a fourth Joule-Thomson expansion device and a fourth tank, the sixth hot channel comprising a sixteenth inlet in fluidic communication with the first working circuit between the first outlet and the third inlet and the sixth cold channel comprises a sixteenth outlet in fluidic communication with the first working circuit downstream of the fifth outlet. 
     
     
         25 . The refrigeration device as claimed in  claim 18 , wherein the first working fluid comprises a volume proportion of helium-4 greater than or equal to 99.9%. 
     
     
         26 . The refrigeration device as claimed in  claim 18 , further comprising a second working circuit for circulating a second working fluid by means of a second transfer member and a second cryogenic pump, the second working circuit comprising at least one first line portion in heat exchange with the first tank. 
     
     
         27 . The refrigeration device as claimed in  claim 26 , wherein the second transfer member is situated outside the enclosure. 
     
     
         28 . The refrigeration device as claimed in  claim 26 , wherein the second working circuit comprises at least one second line portion in heat exchange with the second tank. 
     
     
         29 . The refrigeration device as claimed in  claim 26 , wherein the second working circuit also comprises a fifth Joule-Thomson expansion device. 
     
     
         30 . The refrigeration device as claimed in  claim 26 , wherein the second working fluid comprises a volume proportion of helium-3 greater than or equal to 99.9%. 
     
     
         31 . A method for refrigeration using a device as claimed in  claim 18 , comprising the following steps:
 compression of the first working fluid;   cooling of the first working fluid;   isenthalpic expansion of the first working fluid;   separation of the first working fluid into a first liquid phase and a second gas phase;   heating of the first fluid; and   pumping of the first fluid.   
     
     
         32 . The method as claimed in  claim 31 , wherein the step of isenthalpic expansion of the first working fluid is carried out in such a way as to bring the first working fluid to a temperature of between 500 millikelvin and 4.5 kelvin prior to the separation step. 
     
     
         33 . A method for refrigeration using a device as claimed in  claim 18 , comprising the following steps:
 compressing the second working fluid;   cooling the second working fluid;   isenthalpically expanding the second working fluid;   separating the second working fluid into a first liquid phase and a second gas phase;   heating the second fluid; and   pumping the second fluid.   
     
     
         34 . The method as claimed in  claim 33 , wherein the step of isenthalpic expansion of the second working fluid is carried out in such a way as to bring the second working fluid to a temperature of between 300 and 700 millikelvin prior to the separation step.