Device and method for pre-cooling a stream of a target fluid to a temperature less than or equal to 90 k

Abstract

The device ( 100 ) for pre-cooling a flow ( 101 ) of a target gas to a temperature of less than or equal to 90 K comprises: a group ( 105 ) of at least two heat exchangers ( 106, 107, 108, 136 ) for exchanging heat between the target gas flow, a flow ( 102 ) of a first cooling fluid and at least one flow among a flow of a second cooling fluid and a flow of a third cooling fluid, closed circulation circuit ( 110 ) for a flow of a second cooling fluid, said fluid comprising at least methane, said circuit comprising: at least one compression stage ( 111, 112 ), at least one liquid-gas separation stage ( 115, 116 ) and at least one expansion stage ( 120, 121, 122 ) and a circulation circuit ( 125 ) for a flow of the third cooling fluid through at least one of said heat exchangers.

1 . A device for pre-cooling a flow of a target gas to a temperature less than or equal to 90 K, comprising:
 a group of at least two heat exchangers for exchanging heat between the target gas flow, a flow of a first cooling fluid and at least one flow among a flow of a second cooling fluid and a flow of a third cooling fluid,   
       the target gas downstream of the group of exchangers remaining in gas form,
 a closed circulation circuit for a flow of a second cooling fluid, said fluid comprising at least methane, said circuit comprising: 
 at least one stage of compressing the flow of the second fluid, 
 at least one stage of liquid-gas separation of the flow of the second fluid to form a liquid part and a gas part, at least one of the two parts being provided to at least one said heat exchanger and 
 at least one stage of expanding the flow of the second fluid and 
 a circulation circuit for a flow of the third cooling fluid through at least one of said heat exchangers, said circuit not comprising an expansion turbine, said third fluid having a circulation temperature in said exchanger of less than 90K, said circulation circuits of each cooling fluid being separate. 
 
     
     
         2 . The device according to  claim 1 , wherein the circulation circuit for a flow of the third cooling fluid comprises at least one stage of expanding the flow of the third fluid, the expansion stage comprising a Joule-Thompson valve, upstream of the at least one heat exchanger. 
     
     
         3 . The device according to  claim 2 , wherein the circulation circuit for the flow of the third fluid is configured so that the third cooling fluid comprises a mixture of liquid and gas downstream of the expansion stage. 
     
     
         4 . The device according to  claim 1 , wherein the circulation circuit for the flow of the third fluid is configured to pass through at least two of the heat exchangers of the heat exchanger group. 
     
     
         5 . The device according to  claim 2 , wherein the circulation circuit for a flow of the third cooling fluid comprises the stage of expanding the flow of the third fluid between a third fluid outlet of a heat exchanger among the two of said heat exchangers and a third fluid inlet of a heat exchanger among the two of said heat exchangers. 
     
     
         6 . The device according to  claim 4 , wherein the circulation circuit for a flow of the third cooling fluid comprises at least one stage of compressing the flow of the third fluid between a third fluid outlet of a heat exchanger among the two of said heat exchangers and a third fluid inlet of a heat exchanger among the two of said heat exchangers. 
     
     
         7 . The device according to  claim 6 , which comprises a dedicated heat exchanger for exchanging heat between the flow of the third compressed fluid and at least one part of the flow of the third fluid from a heat exchanger. 
     
     
         8 . The device according to  claim 1 , wherein:
 the circulation circuit for a flow is a closed circulation circuit for a flow of a third cooling fluid or   the circulation circuit for a flow of a third fluid is an open circulation circuit for a flow of a third cooling fluid through at least one heat exchanger.   
     
     
         9 . (canceled) 
     
     
         10 . The device according to  claim 1 , wherein the flow of third cooling fluid is a nitrogen flow. 
     
     
         11 . The device according to  claim 10 , wherein the circulation circuit of the nitrogen flow is configured so that the nitrogen flow is constrained by at least one of the following operating conditions:
 a high pressure of between 22 and 100 bara,   a low pressure of between 1 and 2.2 bara,   a mass ratio of nitrogen to target fluid of between 1 and 8 and/or   an inlet temperature at at least one heat exchanger of between 78 K and 88 K.   
     
     
         12 . The device according to  claim 1 , wherein the flow of third cooling fluid has a liquefaction temperature at atmospheric pressure less than or equal to the liquefaction temperature at atmospheric pressure of the second cooling fluid. 
     
     
         13 . The device according to  claim 1 , wherein:
 a target fluid circuit successively passes through a first heat exchanger and a second heat exchanger of the group,   the closed circulation circuit for the flow of the second cooling fluid also passes through the first heat exchanger and the second heat exchanger and   at least one liquid-gas separation stage for the flow of the second fluid is positioned upstream of the first heat exchanger, at least one of the liquid and gas parts being provided to said first heat exchanger.   
     
     
         14 . The device according to  claim 1 , wherein:
 the heat exchanger group has an intermediate heat exchanger,   a target fluid circuit successively passes through a first heat exchanger of the group, the intermediate heat exchanger and a second heat exchanger of the group,   the closed circulation circuit for the flow of the second cooling fluid also passes through the first heat exchanger, the intermediate heat exchanger and the second heat exchanger and   at least one liquid-gas separation stage for the flow of the second fluid is positioned downstream of the first heat exchanger and upstream of the intermediate heat exchanger, at least one of the liquid and gas parts being provided to said intermediate heat exchanger.   
     
     
         15 . The device according to  claim 1 , which comprises, downstream of a stage of compressing the second cooling fluid:
 a liquid-gas separation stage for the second cooling fluid to form a gas part and a liquid part,   a means of compressing the gas part,   a means of compressing the liquid part and   a means of mixing the compressed gas part and the compressed liquid part.   
     
     
         16 . The device according to  claim 1 , wherein the circulation circuit for the second refrigerant fluid is configured so that the flow of the second refrigerant fluid is constrained by at least one of the following operating conditions:
 a high pressure of between 20 and 36 bara,   a low pressure of between 1 and 2 bara,   a mass ratio of nitrogen to target fluid of between 17.5 and 28,   an inlet temperature at the heat exchanger group of between 86 K and 100 K,   an inlet temperature at an intermediate exchanger of the group of heat exchangers of between 166 K and 210 K and/or   an inlet temperature at a second heat exchanger of the heat exchanger group of between 95 K and 132 K.   
     
     
         17 . The device according to  claim 1 , wherein the flow of target fluid is a hydrogen and/or helium flow. 
     
     
         18 . The device according to  claim 1 , wherein the flow of first refrigerant fluid is a flow comprising or at least or consisting of:
 dihydrogen,   neon, helium or a mixture of neon and helium or   a mixture of neon, helium and dihydrogen.   
     
     
         19 . The device according to  claim 1 , wherein the flow of the second refrigerant fluid is a flow comprising or consisting of a mixture from:
 a mixture of nitrogen, methane, ethylene or ethane, propane or propene and n-butane or i-butane or but-1-ene,   a mixture of methane, ethylene or ethane, propane or propene and n-butane or i-butane or but-1-ene and   a mixture of nitrogen, methane, ethylene or ethane, propane or propene, n-butane or i-butane or but-1-ene and n-pentane or i-pentane.   
     
     
         20 . The device according to  claim 1 , wherein the flow of the second refrigerant fluid consists, in mole percent, of:
   4 % to 14% nitrogen,   26.4% to 40% methane,   14.9% to 36.4% ethylene,   21.5% to 35% propane and   14.8% to 25% butane.   
     
     
         21 . A method for pre-cooling a flow of a target gas to a temperature of less than or equal to 90 K, characterised in that it comprises:
 a step of passing through, by the target gas flow, a group of at least two heat exchangers for exchanging heat between the target gas flow, a flow of a first cooling fluid and at least one flow among a flow of a second cooling fluid and a flow of a third cooling fluid,   a step of circulating a flow of a third cooling fluid through at least one of said heat exchangers, said circulation step not comprising an expansion step performed by an expansion turbine, said third fluid having a circulation temperature in said exchanger less than 90K and   a step of circulating a flow of a second cooling fluid in a closed circuit, said fluid comprising at least methane, said circulation step comprising:   at least one step of compressing the flow of the second fluid,   at least one liquid-gas separation step for the flow of the second fluid to form a liquid part and a gas part, at least one of the two parts being provided to at least one said heat exchanger and   at least one step of expanding the flow of the second fluid.