Method and device for cryogenic cooling

Abstract

Method for cryogenic cooling of a first fluid by heat exchange with at least one second fluid in a heat exchanger, the first fluid and/or the second fluid being at a temperature between −100° C. and −273° C., wherein the heat exchanger is of the type with polymer microtubes, i.e. comprising a plurality of microtubes made of polymer and having a diameter of between 0.1 mm and 1 cm, one of the first and second fluids being circulated inside said microtubes while the other fluid is circulated around said microtubes.

1 - 15 . (canceled) 
     
     
         16 . A method for cryogenic cooling of a first fluid by heat exchange with at least one second fluid in a heat exchanger, the first fluid and/or the second fluid being at a temperature of between −100° C. and −273° C.;
 providing the heat exchanger that is of a type with polymer microtubes, that is to say comprising a plurality of microtubes made of polymer and having a diameter of between 0.1 mm and 1 mm; and 
 circulating one of the first and second fluids inside said microtubes while the other of the first and second fluids is circulated around said microtubes, 
 wherein the heat exchanger comprises a casing in which the microtubes are arranged, the casing comprising a first inlet communicating with a first end of the microtubes, the casing comprising a first outlet communicating with a second end of the microtubes, the casing also comprising a second inlet and a second outlet communicating with the space around the microtubes. 
 
     
     
         17 . The method as claimed in  claim 16 , wherein the microtubes include material selected from the group consisting of: polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE), polyetherimide, polyimides, polyamides, polycarbonates, any other plastic material compatible with use at said low temperatures, and combinations thereof. 
     
     
         18 . The method as claimed in  claim 16 , wherein the microtubes include a material comprising a mixture of polyetherimide (“Ultem”) and PEEK. 
     
     
         19 . The method as claimed in  claim 16 , wherein the microtubes include a material having a mass per unit volume of between 2700 kg/m 3  and 900 kg/m 3 . 
     
     
         20 . The method as claimed in  claim 16 , wherein the microtubes have a diameter of between 0.1 mm and 5 mm. 
     
     
         21 . The method as claimed in  claim 16 , wherein a pressure differential between a pressure of the fluid circulated in the microtubes and a pressure of the fluid circulated around the microtubes is between 1 bar and 100 bar. 
     
     
         22 . The method as claimed in  claim 16 , wherein the microtubes are arranged in a bundle along a longitudinal direction in the casing. 
     
     
         23 . The method as claimed in  claim 22 , wherein at least one of the two longitudinal ends of the bundle of microtubes comprises a layer of rigid material such as a thermosetting material, that is configured to ensure the cohesion of the microtube bundle, the casing housing at least one elastic member stressed in the longitudinal direction between a stop formed in the casing and a longitudinal end of the microtube bundle, to ensure the longitudinal retention of the microtube bundle while allowing expansion or contraction relative to the casing in the longitudinal direction. 
     
     
         24 . The method as claimed in  claim 16 , wherein the microtubes are wound in a coil. 
     
     
         25 . The method as claimed in  claim 16 , wherein the microtubes are wound in a coil that is distributed around a central support core. 
     
     
         26 . The method as claimed in  claim 25 , wherein at least one of the two longitudinal ends of the bundle of microtubes comprises a layer of rigid material such as a thermosetting material, ensuring the cohesion of the microtube bundle, the casing housing at least one elastic member stressed in the longitudinal direction between a stop formed in the casing and a longitudinal end of the microtube bundle, to ensure the longitudinal retention of the microtube bundle while allowing expansion or contraction relative to the casing in the longitudinal direction. 
     
     
         27 . The method as claimed in  claim 26 , wherein the casing comprises an elastic area disposed along the longitudinal direction. 
     
     
         28 . The method as claimed in  claim 26 , wherein the elastic member comprises at least one of a spring, a coil spring, and one or more spring washers. 
     
     
         29 . The method as claimed in  claim 28 , wherein the casing comprises an elastic area disposed along the longitudinal direction. 
     
     
         30 . The method as claimed in  claim 16 , wherein separate portions of the microtubes and/or of the space around the microtubes receive separate flows of fluid(s) for the purpose of heat exchanges in the heat exchanger, such that an exchange of heat between more than two fluids occurs. 
     
     
         31 . The method as claimed in  claim 16 , wherein the cooling takes place in a process of cryogenic refrigeration and/or liquefaction of a fluid, the heat exchanger being located in a cryogenic refrigeration and/or liquefaction device. 
     
     
         32 . A device for cryogenic cooling of at least one first fluid by heat exchange with at least one second fluid, the device comprising:
 a heat exchanger providing an exchange of heat between the first fluid and the second fluid, the first and/or the second fluid being at a temperature between −100° C. and −273° C., the heat exchanger being of the type with polymer microtubes, that is to say comprising a plurality of microtubes made of polymer and having a diameter of between 0.1 mm and 1 mm, and in that the heat exchanger comprises:
 a casing in which the microtubes are arranged, the casing comprising:
 a first inlet communicating with a first end of the microtubes, 
 a first outlet communicating with a second end of microtubes, 
 a second inlet and a second outlet communicating with a space around the microtubes, 
 
   wherein the heat exchanger further comprises means for circulation of the first fluid inside said microtubes and means for circulation of the second fluid around said microtubes.   
     
     
         33 . The cooling device as claimed in  claim 32 , wherein the device comprises a working circuit containing a working fluid, the working circuit comprising at least one compressor for the working gas, at least one heat exchanger for cooling the compressed fluid, at least one expansion member for expanding the working fluid, and at least one heat exchanger for heating the expanded working fluid, wherein the at least one cooling heat exchanger and/or the at least one heating heat exchanger is of the type with polymer microtubes, that is to say comprising a plurality of microtubes made of polymer and having a diameter of between 0.1 mm and 10 mm, and comprising inlets and outlets for a first flow of working fluid and another fluid having a separate temperature from the temperature of the first flow of working fluid, to provide a heat exchange between the first flow of working fluid and the other fluid.