Hybrid gas liquefaction cycle with multiple expanders
First Claim
1. A method for gas liquefaction comprising (a) cooling a feed gas in a first heat exchange zone by indirect heat exchange with one or more refrigerant streams provided in a first refrigeration system, and withdrawing a substantially liquefied stream from the first heat exchange zone;
- (b) further cooling the substantially liquefied stream in a second heat exchange zone by indirect heat exchange with one or more work-expanded refrigerant streams provided by a second refrigeration system and withdrawing a further cooled, substantially liquefied stream from the second heat exchange zone; and
(c) work expanding two or more cooled compressed refrigerant streams in the second refrigeration system to provide at least one of the one or more work-expanded refrigerant streams in the second heat exchange zone, wherein the operation of the second refrigeration system includes the steps of (1) compressing one or more refrigerant gases to provide a compressed refrigerant stream;
(2) cooling all or a portion of the compressed refrigerant stream in a third heat exchange zone to provide a cooled, compressed refrigerant stream; and
(3) work expanding the cooled, compressed refrigerant stream to provide one of the one or more work-expanded refrigerant streams;
wherein the flow rate of a work-expanded refrigerant stream in the second heat exchange zone is less than the total flow rate of one or more work-expanded refrigerant streams in the third heat exchange zone.
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Accused Products
Abstract
Method for gas liquefaction comprising cooling a feed gas by a first refrigeration system in a first heat exchange zone and withdrawing a substantially liquefied stream therefrom, further cooling the substantially liquefied stream by indirect heat exchange with one or more work-expanded refrigerant streams in a second heat exchange zone, and withdrawing therefrom a further cooled, substantially liquefied stream. At least one of the one or more work-expanded refrigerant streams is provided by compressing one or more refrigerant gases to provide a compressed refrigerant stream, cooling all or a portion of the compressed refrigerant stream in a third heat exchange zone to provide a cooled, compressed refrigerant stream, and work expanding the cooled, compressed refrigerant stream to provide one of the one or more work-expanded refrigerant streams. The flow rate of a work-expanded refrigerant stream in the second heat exchange zone typically is less than the total flow rate of one or more work-expanded refrigerant streams in the third heat exchange zone.
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Citations
32 Claims
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1. A method for gas liquefaction comprising
(a) cooling a feed gas in a first heat exchange zone by indirect heat exchange with one or more refrigerant streams provided in a first refrigeration system, and withdrawing a substantially liquefied stream from the first heat exchange zone; -
(b) further cooling the substantially liquefied stream in a second heat exchange zone by indirect heat exchange with one or more work-expanded refrigerant streams provided by a second refrigeration system and withdrawing a further cooled, substantially liquefied stream from the second heat exchange zone; and
(c) work expanding two or more cooled compressed refrigerant streams in the second refrigeration system to provide at least one of the one or more work-expanded refrigerant streams in the second heat exchange zone, wherein the operation of the second refrigeration system includes the steps of (1) compressing one or more refrigerant gases to provide a compressed refrigerant stream;
(2) cooling all or a portion of the compressed refrigerant stream in a third heat exchange zone to provide a cooled, compressed refrigerant stream; and
(3) work expanding the cooled, compressed refrigerant stream to provide one of the one or more work-expanded refrigerant streams;
wherein the flow rate of a work-expanded refrigerant stream in the second heat exchange zone is less than the total flow rate of one or more work-expanded refrigerant streams in the third heat exchange zone. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method for gas liquefaction comprising:
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(a) cooling a feed gas in a first heat exchange zone by indirect heat exchange with one or more refrigerants provided in a first refrigeration system, and withdrawing a substantially liquefied stream from the first heat exchange zone; and
(b) further cooling the substantially liquefied stream in a second heat exchange zone by indirect heat exchange with a cold work-expanded refrigerant and withdrawing therefrom a further cooled, substantially liquefied stream;
wherein the cold work-expanded refrigerant is provided in a second refrigeration system comprising at least two refrigeration circuits by a method which includes (1) compressing a refrigerant gas in a first refrigeration circuit to provide a compressed refrigerant gas;
(2) cooling the compressed refrigerant gas in a third heat exchange zone to provide a cooled, compressed refrigerant gas, wherein a portion of the cooling is provided therein by vaporizing a multicomponent refrigerant provided by a second refrigeration circuit;
(3) work expanding the cooled, compressed refrigerant gas to provide the cold work-expanded refrigerant; and
(4) warming the cold work-expanded refrigerant in the second heat exchange zone to provide refrigeration therein for cooling the substantially liquefied stream from the first heat exchange zone and to provide refrigeration for cooling the compressed refrigerant gas in the third heat exchange zone, and withdrawing therefrom a warmed refrigerant to provide the refrigerant gas. - View Dependent Claims (25)
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26. In a method for gas liquefaction comprising
(a) cooling a feed gas in a first heat exchange zone by indirect heat exchange with one or more refrigerants provided in a first refrigeration system, thereby providing a cooled feed stream; - and
(b) further cooling the cooled feed stream in a second heat exchange zone by indirect heat exchange with a work-expanded refrigerant provided by a second refrigeration system and withdrawing a further cooled stream from the second heat exchange zone, wherein the operation of the second refrigeration system includes the steps of (1) compressing a refrigerant gas to provide a compressed refrigerant;
(2) cooling the compressed refrigerant to provide a cooled, compressed refrigerant;
(3) work expanding the cooled, compressed refrigerant to provide the work-expanded refrigerant;
wherein refrigeration for the cooling of the compressed refrigerant is provided in part by indirect heat exchange in a third heat exchange zone with work-expanded refrigerant from the second heat exchange zone and in part by balance refrigeration provided by the first refrigeration system;
the improvement comprising reducing or eliminating the need for the balance refrigeration by cooling and work expanding a portion of the compressed refrigerant to provide an additional work-expanded refrigerant, and utilizing the additional work-expanded refrigerant to provide additional refrigeration to the third heat exchange zone.
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27. A system for gas liquefaction comprising:
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(a) a first refrigeration system and first heat exchange means adapted for cooling a feed gas by indirect heat exchange with one or more refrigerants provided by the first refrigeration system in order to provide a substantially liquefied stream;
(b) a second refrigeration system and second heat exchange means adapted for further cooling of the substantially liquefied stream by indirect heat exchange with one or more cold work-expanded refrigerants provided by the second refrigeration system in order to provide a further cooled, substantially liquefied stream;
(c) gas compression means for compressing one or more refrigerant gas streams and third heat exchange means adapted for cooling one or more compressed refrigerant gas streams in the second refrigeration system;
(d) two or more expanders for work expanding cooled compressed refrigerant gas streams in the second refrigeration system to provide two or more cold work-expanded refrigerant streams; and
(e) piping means to transfer the two or more cold work-expanded refrigerant streams from the two or more expanders to the second heat exchange means or to the second and third heat exchange means. - View Dependent Claims (28, 29, 30)
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31. A system for gas liquefaction comprising:
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(a) a first refrigeration system and first heat exchange means adapted for cooling a feed gas by indirect heat exchange with one or more refrigerants provided by the first refrigeration system in order to provide a substantially liquefied stream;
(b) a second refrigeration system and second heat exchange means adapted for further cooling of the substantially liquefied stream by indirect heat exchange with one or more cold work-expanded refrigerants provided by the second refrigeration system in order to provide a further cooled, substantially liquefied stream;
(c) gas compression means for compressing a refrigerant gas stream and third heat exchange means adapted for cooling one or more compressed refrigerant streams;
(d) a third refrigeration system adapted to provide additional refrigeration to the third heat exchange means;
(e) an expander for work expanding a cooled compressed refrigerant stream in the second refrigeration system to provide a cold work-expanded refrigerant stream; and
(f) piping means to transfer the cold work-expanded refrigerant stream from the expander to the second heat exchange means. - View Dependent Claims (32)
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Specification