Gas liquefaction process and refrigeration plant

• US 5,205,134 A
• Filed: 10/16/1991
• Issued: 04/27/1993
• Est. Priority Date: 10/26/1990
• Status: Expired due to Fees

• Current Assignee: L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Original Assignee: L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Inventors: Gistau-Baguer, Guy
• Primary Examiner(s): Cohan, Alan
• Application Number:
  US07/777,139
• Time in Patent Office: 559 Days
• Field of Search: 62/9, 62/11, 62/335, 62/79
• US Class Current: 62/335
• CPC Class Codes: F25B 9/06 using expanders F25B9/10 takes precedence
• CPC Class Codes: F25J 1/0007 Helium
• CPC Class Codes: F25J 1/0035 by gas expansion with extraction of work
• CPC Class Codes: F25J 1/0037 of a return stream
• CPC Class Codes: F25J 1/004 by flash gas recovery F25J1/0267 takes precedence
• CPC Class Codes: F25J 1/0042 by liquid expansion with extraction of work
• CPC Class Codes: F25J 1/005 by expansion of a gaseous refrigerant stream with extraction of work
• CPC Class Codes: F25J 1/0065 Helium
• CPC Class Codes: F25J 1/0202 in a quasi-closed internal refrigeration loop F25J1/0208, F25J1/0219, F25J1/0224 take precedence
• CPC Class Codes: F25J 1/0257 Construction and layout of liquefaction equipments, e.g. valves, machines F25J1/0279 takes precedence
• CPC Class Codes: F25J 1/0276 Laboratory or other miniature devices
• CPC Class Codes: F25J 2240/02 Expansion of a process fluid in a work-extracting turbine (i.e. isentropic expansion), e.g. of the feed stream
• CPC Class Codes: F25J 2240/30 Dynamic liquid or hydraulic expansion with extraction of work, e.g. single phase or two-phase turbine
• CPC Class Codes: F25J 2270/06 with multiple gas expansion loops
• CPC Class Codes: F25J 2270/16 with mutliple gas expansion loops of the same refrigerant
• CPC Class Codes: F25J 2270/912 Liquefaction cycle of a low-boiling (feed) gas in a cryocooler, i.e. in a closed-loop refrigerator

Abstract

The liquefaction process comprises the stages of pre-cooling (3) the gas, of cooling it by heat exchange (6, 7, 8) and by fractional expansion (10, 11), under supercritical conditions, then of expanding it in a turbine (9) which delivers a volume of subcooled liquid (2). The process is especially applicable to the refrigeration of superconductive elements.

Claims

1. A refrigeration plant having a cooling circuit of a fluid having a low boiling point comprising, serially arranged:

a pre-cooling stage,

a refrigeration stage comprising, in series, a first heat exchanger, a first turbine, a second heat exchanger, a second turbine, and a third heat exchanger,

a downstream dynamic expansion device, and

a liquid fluid reservoir.

2. The plant of claim 1, wherein the downstream dynamic expansion device is a turbine.

3. The plant of claim 2, having a heating circuit leading from the reservoir through the refrigeration stage and the pre-cooling stage, wherein the pre-cooling stage comprises a downstream heat exchanger and a turbine by-passing part of the fluid in the cooling circuit before it reaches the downstream heat exchanger.

4. The plant of claim 1, wherein the downstream dynamic expansion device is comprised of a cylinder and piston assembly of a two-piston reciprocating expansion machine.