High temperature superconductor refrigeration system

Abstract

A cryogenic refrigeration system and a corresponding method for increasing the cooling efficiency of the system, preferably the cooling of a thermally coupled load. Accordingly, the system comprises a supply means for providing a supply flow of a cryogenic refrigerant, a compressor fluidly coupled to said supply means and configured to compress the supplied cryogenic refrigerant, and a cold box fluidly coupled to the compressor, said cold box comprising a first expansion device and a first heat exchanger, wherein the first expansion device is configured to receive the compressed cryogenic refrigerant from the compressor and expand it and provide the expanded refrigerant to the first heat exchanger, and wherein the first heat exchanger is configured to be thermally coupled to a load. The system furthermore comprises a second heat exchanger arranged in the cold box comprising at least a first and second heat exchanging section.

1 . Cryogenic refrigeration system ( 1 ), comprising:
 a supply means ( 2 ) for providing a supply flow of a cryogenic refrigerant;   a compressor ( 3 ) fluidly coupled to said supply means ( 2 ) and configured to compress the supplied cryogenic refrigerant; and   a cold box ( 10 ) fluidly coupled to the compressor ( 3 ), said cold box ( 10 ) comprising a first expansion device ( 4 ) and a first heat exchanger ( 5 ),   wherein the first expansion device ( 4 ) is configured to receive the compressed cryogenic refrigerant ( 20 ) from the compressor ( 3 ) and expanded and provide the expanded refrigerant to the first heat exchanger ( 5 ), and   wherein the first heat exchanger ( 5 ) is configured to be thermally coupled to a load ( 7 ), wherein
 the system ( 1 ) comprises a second heat exchanger ( 6 ) arranged in the cold box ( 10 ) comprising at least a first heat exchanging section ( 6 A) and a second heat exchanging section ( 6 B), 
 wherein the first heat exchanging section ( 6 A) is configured to receive the expanded refrigerant ( 22 ) from the expansion device ( 4 ) and to subsequently provide the expanded refrigerant ( 22 ) to the first heat exchanger ( 5 ); 
 wherein the second heat exchanging section ( 6 B) is configured to receive the expanded refrigerant ( 24 ) from the first heat exchanger ( 5 ) and to subsequently provide the received expanded refrigerant ( 24 ) to the first heat exchanger ( 5 ), 
 wherein the first and second heat exchanger sections ( 6 A,  6 B) are thermally coupled, and wherein the first heat exchanger ( 5 ) is configured to provide the received expanded refrigerant ( 24 ) to the supply means ( 2 ) and/or the compressor ( 3 ). 
   
     
     
         2 . Cryogenic refrigeration system ( 1 ) according to  claim 1 , wherein the cold box ( 10 ) further comprises a second expansion device ( 40 ) and the second heat exchanger ( 6 ) comprises a third and a fourth heat exchanging section ( 6 C,  6 D), wherein
 the second expansion device ( 40 ) is fluidly coupled to the first heat exchanger ( 5 ) and the second heat exchanger ( 6 ) and is configured to receive the expanded refrigerant ( 24 ) received by the first heat exchanger ( 5 ) from the second heat exchanging section ( 6 B), provide a secondary expansion of said refrigerant ( 24 ), and subsequently provide the secondary expanded refrigerant ( 26 ) to the first heat exchanger ( 5 ) via the third heat exchanging section ( 6 C), and   the fourth heat exchanging section ( 6 D) is configured to receive the secondary expanded refrigerant ( 28 ) from the first heat exchanger ( 5 ) and to subsequently provide the received secondary expanded refrigerant ( 28 ) to the first heat exchanger ( 5 ),   wherein at least the third and fourth heat exchanger sections ( 6 C,  6 D) are thermally coupled.   
     
     
         3 . Cryogenic refrigeration system ( 1 ) according to  claim 1 , wherein the compressor ( 3 ) is a screw compressor or turbo compressor, said turbo compressor preferably comprising magnetic couplings and/or comprising a serial compressor, and/or wherein the compressor is configured to compress the refrigerant at ambient temperature. 
     
     
         4 . Cryogenic refrigeration system ( 1 ) according to  claim 1 , wherein the first heat exchanger ( 5 ) is thermally coupled to a load ( 7 ), said load ( 7 ) preferably comprising a refrigeration circuit ( 70 ) for a high temperature superconductor. 
     
     
         5 . Cryogenic refrigeration system ( 1 ) according to  claim 4 , said load ( 7 ) comprising a second cryogenic refrigerant, wherein said second cryogenic refrigerant preferably comprises liquid nitrogen. 
     
     
         6 . Cryogenic refrigeration system ( 1 ) according to  claim 1 , wherein at least the first and second heat exchanging sections ( 6 A,  6 B) and/or the third and fourth heat exchanging sections ( 6 C,  6 D) are arranged with respect to each other such that they provide counter flow, cross flow, or equal flow heat exchanging sections. 
     
     
         7 . Cryogenic refrigeration system ( 1 ) according to  claim 1 , wherein the compressor ( 3 ) and/or the supply means ( 2 ) are configured to provide the refrigerant to the first expansion device ( 4 ) is a liquid refrigerant, preferably also to the second expansion device ( 40 ). 
     
     
         8 . Cryogenic refrigeration system ( 1 ) according to  claim 1 , wherein the first expansion device ( 4 ) is configured to provide a two-phase or gas phase refrigerant; and wherein the first heat exchanger ( 5 ) is configured as a cold gas heat exchanger and wherein the first heat exchanger ( 5 ) is configured is to receive a gas phase from the cooled refrigerant ( 22 ). 
     
     
         9 . Cryogenic refrigeration system ( 1 ) according to  claim 1 , wherein the cryogenic refrigerant comprises helium and/or neon. 
     
     
         10 . Cryogenic refrigeration system ( 1 ) according to  claim 1 , wherein the system further comprises in evaporating heat exchanger ( 8 A) arranged outside of the cold box ( 10 ) and upstream of the first expansion device ( 4 ), which is thermally coupled to the provided compressed cryogenic refrigerant supply flow to pre-cool said refrigerant, wherein the evaporating heat exchanger ( 8 A) preferably comprises a liquid water circuit ( 80 ) as a refrigerant to be evaporated. 
     
     
         11 . Cryogenic refrigeration system ( 1 ) according to  claim 1 , wherein the system further comprises in evaporating heat exchanger ( 8 B) arranged in the cold box ( 10 ) and upstream of the first expansion device ( 4 ), which is thermally coupled to the provided compressed cryogenic refrigerant supply flow to pre-cool said refrigerant, wherein the evaporating heat exchanger ( 8 B) preferably comprises a liquid nitrogen circuit ( 82 ) as a refrigerant to be evaporated. 
     
     
         12 . Method for providing a cryogenic refrigeration, comprising the steps of:
 providing a supply flow of a cryogenic refrigerant with a supply means ( 2 );   compressing the supplied cryogenic refrigerant with a compressor ( 3 );   expanding the compressed cryogenic refrigerant ( 20 ) in a first expansion device ( 4 ) provided in a cold box ( 10 ), wherein the cold box is configured to be thermally coupled to a load ( 7 ); and   providing the expanded refrigerant ( 22 ) to a first heat exchanger ( 5 ) in the cold box ( 10 )   wherein   the expanded refrigerant ( 22 ) is received from the expansion device ( 4 ) by a first heat exchanging section ( 6 A) of a second heat exchanger ( 6 ) in the cold box ( 10 ) and is subsequently provided to the first heat exchanger ( 5 );   the expanded refrigerant ( 24 ) from the first heat exchanger ( 5 ) is received by a second heat exchanging section ( 6 B) of the second heat exchanger ( 6 ) and is subsequently provided to the first heat exchanger ( 5 ); and   wherein heat is exchanged between the first and second heat exchanger section ( 6 A,  6 B) and wherein the expanded refrigerant ( 24 ) received by the first heat exchanger ( 5 ) from the second heat exchanging section ( 6 B) is provided to the supply means ( 2 ) and/or the compressor ( 3 ).   
     
     
         13 . Method according to  claim 12 , wherein
 the expanded refrigerant ( 24 ) received by the first heat exchanger ( 5 ) from the second heat exchanging section ( 6 B) is received and expanded by a second expansion device ( 40 ), wherein the secondary expanded refrigerant ( 26 ) is provided to the first heat exchanger ( 5 ) via a third heat exchanging section ( 6 C) of the second heat exchanger ( 6 ),   the secondary expanded refrigerant ( 28 ) from the first heat exchanger ( 5 ) is received by a fourth heat exchanging section ( 6 D) of the second heat exchanger ( 6 ) and subsequently provided via the fourth heat exchanging section ( 6 D) to the first heat exchanger ( 5 ), and   heat is exchanged between at least the third and fourth heat exchanger section ( 6 C,  6 D).   
     
     
         14 . Method according to  claim 12 , wherein the supplied cryogenic refrigerant is compressed by a screw compressor, a turbo compressor, and/or at ambient temperature, wherein the cryogenic refrigerant preferably comprises helium and/or neon. 
     
     
         15 . Method according to  claim 12 , wherein the first heat exchanger ( 5 ) provides a cryogenic refrigeration of a thermally coupled load ( 7 ), said load ( 7 ) preferably comprising a refrigeration circuit ( 70 ) for a high-temperature superconductor, wherein preferably the load ( 7 ) comprises liquid nitrogen as a second cryogenic refrigerant.