Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/0002—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the fluid to be liquefied
  • F25J1/0022—Hydrocarbons, e.g. natural gas
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
  • F25J1/0032—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration"
  • F25J1/0035—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration" by gas expansion with extraction of work
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
  • F25J1/0047—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle
  • F25J1/005—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle by expansion of a gaseous refrigerant stream with extraction of work
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
  • F25J1/0047—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle
  • F25J1/0052—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle by vaporising a liquid refrigerant stream
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/006—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the refrigerant fluid used
  • F25J1/007—Primary atmospheric gases, mixtures thereof
  • F25J1/0072—Nitrogen
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
  • F25J1/0203—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a single-component refrigerant [SCR] fluid in a closed vapor compression cycle
  • F25J1/0204—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a single-component refrigerant [SCR] fluid in a closed vapor compression cycle as a single flow SCR cycle
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
  • F25J1/0211—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a multi-component refrigerant [MCR] fluid in a closed vapor compression cycle
  • F25J1/0212—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a multi-component refrigerant [MCR] fluid in a closed vapor compression cycle as a single flow MCR cycle
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
  • F25J1/0228—Coupling of the liquefaction unit to other units or processes, so-called integrated processes
  • F25J1/0232—Coupling of the liquefaction unit to other units or processes, so-called integrated processes integration within a pressure letdown station of a high pressure pipeline system
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
  • F25J1/0228—Coupling of the liquefaction unit to other units or processes, so-called integrated processes
  • F25J1/0235—Heat exchange integration
  • F25J1/0242—Waste heat recovery, e.g. from heat of compression
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
  • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
  • F25J1/0257—Construction and layout of liquefaction equipments, e.g. valves, machines
  • F25J1/0262—Details of the cold heat exchange system
  • F25J1/0264—Arrangement of heat exchanger cores in parallel with different functions, e.g. different cooling streams
  • F25J1/0265—Arrangement of heat exchanger cores in parallel with different functions, e.g. different cooling streams comprising cores associated exclusively with the cooling of a refrigerant stream, e.g. for auto-refrigeration or economizer
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
  • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
  • F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
  • F25J1/0281—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc. characterised by the type of prime driver, e.g. hot gas expander
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
  • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
  • F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
  • F25J1/0281—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc. characterised by the type of prime driver, e.g. hot gas expander
  • F25J1/0284—Electrical motor as the prime mechanical driver
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
  • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
  • F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
  • F25J1/0285—Combination of different types of drivers mechanically coupled to the same refrigerant compressor, possibly split on multiple compressor casings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
  • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
  • F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
  • F25J1/0285—Combination of different types of drivers mechanically coupled to the same refrigerant compressor, possibly split on multiple compressor casings
  • F25J1/0288—Combination of different types of drivers mechanically coupled to the same refrigerant compressor, possibly split on multiple compressor casings using work extraction by mechanical coupling of compression and expansion of the refrigerant, so-called companders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
  • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
  • F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
  • F25J1/0296—Removal of the heat of compression, e.g. within an inter- or afterstage-cooler against an ambient heat sink
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2210/00—Processes characterised by the type or other details of the feed stream
  • F25J2210/06—Splitting of the feed stream, e.g. for treating or cooling in different ways
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2230/00—Processes or apparatus involving steps for increasing the pressure of gaseous process streams
  • F25J2230/20—Integrated compressor and process expander; Gear box arrangement; Multiple compressors on a common shaft
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2240/00—Processes or apparatus involving steps for expanding of process streams
  • F25J2240/90—Hot gas waste turbine of an indirect heated gas for power generation

Definitions

• the present invention relates to a station for lowering the pressure of a gas and liquefying the gas, especially natural gas.
• the field of the present invention is that of the treatment of gases, in particular natural gases, for the production of liquid natural gas.
• Liquid natural gas is used in different applications. It is mainly used as fuel for vehicles, including transport trucks.
• the fuel generally used for such vehicles can indeed be replaced by pressurized gas or liquid natural gas.
• the use of liquefied gas has an advantage in terms of volume and weight, on the one hand, where the liquefied liquid natural gas by cooling occupies much less the same amount of gaseous natural gas and, on the other hand, where the thermal insulation of the cryogenic tanks is much lighter than the envelope of the gas cylinders.
• the vehicles have a lot more autonomy.
• Liquid natural gas is also a source of clean energy, limiting the release of fine particles such as soot, etc. .
• Liquid natural gas can also be used to power small gas plants or to power small networks in villages.
• Pipelines, or pipelines, are pipelines for the transport of gaseous substances under pressure.
• the majority of pipelines transport natural gas between extraction zones and consumption or export zones. From deposit processing or storage sites, the gas is transported at high pressure (from 16 to over 100 bar) to delivery sites where it must be brought to a much reduced pressure to allow its use.
• the gas passes through pressure reducing stations, in which the pressure of the gas is reduced by expansion through a valve or a turbine. Reducing the pressure in this way produces energy that, in the case of a valve, is lost.
• gas expansion systems using natural gas entering the pressure lowering stations as a refrigerant in a system that can be described as open loop (Linde, Solvay or Claude cycles). In these systems, we use the fact that natural gas comes under high pressure. Natural gas is expanded in a valve and during this expansion a small part of the gas is liquefied. The resulting liquid is collected and cold low pressure natural gas leaving the valve is routed to the low pressure conduit of the lowering station.
• the liquefied gases with these systems are mainly heavy gases such as the butane or propane but not methane. This method of gas liquefaction is also known as flashing.
• the present invention aims in particular to provide means for, at a pressure lowering station, liquefying gas, including natural gas, by controlling the composition of the liquid gas obtained.
• a device according to the invention will recover relaxation energy resulting from the pressure difference of the gas between the inlet and the outlet of the pressure lowering station to produce a fraction of liquid natural gas while avoiding the formation of ice inside the ducts of these stations.
• the device will also be easy preference to implement and simple design.
• the present invention provides a station for lowering the pressure of a gas and liquefying gas, in particular natural gas, comprising:
• a refrigeration system comprising compression means, and
• condensation means for liquefying gas.
• this station also comprises heat recovery means produced by the compression means of the refrigeration system associated with means for heating the gas upstream of the expansion turbine.
• Such a station thus plans to integrate the heating of natural gas before its expansion and the cooling of the refrigerant while saving a significant amount of energy and / or gas for the manufacture of (natural) liquid gas.
• a gas flow (natural) in gaseous form is always kept between a high pressure line and a low pressure line associated with a pressure lowering station.
• On a volume of 100 m 3 of natural gas is transformed for example 5 to 15 m 3 liquid natural gas.
• work can be recovered during the relaxation between the two pressure levels to be used for the transformation of a small part (5 to 15%) of the (natural) gas into liquefied (natural) gas.
• the heating of the gas is carried out for example at the inlet of the pressure lowering station (that is to say upstream of the expansion turbine) by recovering the heat emitted by the compression means used for the liquefaction of the gas.
• the gas from the high pressure duct to the low pressure duct is thus heated before entering the pressure lowering station so that it is at the outlet thereof with a temperature greater than solidification of the water.
• the station comprises a closed loop between the condensation means, the compression means and the means for heating the natural gas.
• This closed loop makes it possible to combine a refrigeration system (compressor and condenser) for the liquefaction of the gas with a heat exchanger achieving the thermal integration between the lowering of the pressure of the gas and the production of liquid gas.
• the station comprises a first closed loop between the compression means, the condensation means and at least one intermediate heat exchanger and a second closed loop, optionally using a coolant distinct from a coolant used in the first loop, between at least one intermediate exchanger and the means for heating the gas.
• a station with an intermediate system similar to a closed loop, possibly double, for cooling a fraction of the gas to liquefaction is proposed here, with these two embodiments.
• the advantage of an independent closed-loop system is that it makes it possible to reach significantly lower temperatures insofar as it is not related to the pressure drop achieved within the pressure lowering station. Thanks to this system, the composition of the liquid gas hardly varies with respect to the inlet gas, since the change of state is obtained by direct cooling inside a heat exchanger reserved for this operation. place of the classic flashing system.
• the means for recovering a mechanical work produced during the lowering of the gas pressure are associated with mechanical work conversion means. electric energy.
• the means for recovering a mechanical work produced during the lowering of the pressure of the gas can be mechanically coupled to an electric generator, and the compression means are then advantageously driven by a motor supplied with electrical energy by the electric generator.
• the means for recovering a mechanical work produced during the lowering of the gas pressure are mechanically associated with the compression means.
• An auxiliary motor may optionally be provided for driving the compression means.
• the liquid natural gas can be produced in a station according to the invention from a refrigeration unit involving a refrigerating system using either nitrogen and / or a mixture of hydrocarbons.
• a refrigeration system used in a station according to the invention may for example comprise a heat exchanger and / or a PFHE type aluminum condenser.
• the refrigeration system comprises compressors and / or radial flow expander.
• the station according to the invention comprises means for treating the water and carbon dioxide of the low-pressure natural gas by adsorption and / or absorption arranged upstream of the gas condensation means.
• FIG. 1 is a very schematic overall view illustrating a station according to the present invention
• FIG. 2 is a more detailed schematic view showing a first embodiment of the present invention
• FIG. 3 is a view similar to the view of FIG. 2 illustrating a second embodiment of the invention
• FIG. 4 is a view similar to that of FIGS. 2 and 3 for a third embodiment of the present invention.
• Figure 5 is a view similar to that of Figures 2 to 4 for a fourth embodiment of the present invention.
• FIG. 1 schematically represents a gas pipeline 2 carrying a gas, for example natural gas composed mainly of methane, under high pressure, for example of the order of 60 to 100 bar (generally in the present application, the examples and numerical values are illustrative and not limiting).
• a gas pressure lowering station called PLD is shown in FIG. 1 to supply a pipe 4 intended to feed a domestic network or the like with gas (gas). natural to resume the previous example) under low pressure, usually of the order of a few bars.
• a liquefied gas production unit 6 is associated with the PLD pressure lowering station. It is supplied with gas from the pipeline 2, downstream of the pressure lowering station PLD, passes through a treatment unit 8 performing a gas treatment before entering the production unit 6 to eliminate gas impurities that are usually found in "raw" gas. At the output of the production unit 6, LNG liquid natural gas is obtained which is for example stored in a storage unit (not shown in FIG. 1).
• the gas yields mechanical work WM. It is proposed here to recover all or part of this work, in any form, mechanical or electrical for example, to power the production unit 6 which requires energy to pass the gas from its gaseous state to a state liquid. Since the recovered energy is not sufficient for the production of liquid gas, it is possible to feed the production unit with a complementary energy source, for example electrical energy represented schematically by WE in Figure 1. Finally, at the level of the Production 6, there is generally a compressor (not shown in Figure 1) or other device that releases heat, schematized by Q in Figure 1. It is proposed in an original way to recover this amount of heat Q to heat the gas input of the pressure lowering station PLD. Indeed, during a relaxation, the relaxed gas cools. It may fall below the solidification temperature of the water and thus cause frost formation that may lead to a partial or complete obstruction of the corresponding pipe. By heating the gas before the relaxation, it can thus limit the risk of icing and obstruction.
• FIG. 2 shows in more detail a first embodiment of the invention embodying the overall diagram of FIG. 1.
• FIG. 2 as in the following, the references in FIG. 1 have been used to designate similar elements.
• FIG. 2 there is a gas pipeline 2 which supplies a pressure lowering station PLD for supplying gas under less pressure in a pipe 4.
• a production unit 6 supplies liquefied gas LNG.
• the production unit 6 essentially comprises a condenser 14.
• the gas supplying the production unit 6 is supplied from a bypass G9 of the pipe G7 before reaching a valve 16 at which an additional pressure reduction is performed.
• the gas is led via a line G10 to the treatment unit 8 which carries out a purification of the gas, for example by absorption or preferably by adsorption.
• the purified gas is led by G1 1 to a desuperheater 18 before being introduced by G12 into the condenser 14.
• liquefied gas is obtained which passes through a line L1 to a control valve 20 then by L2 for arrive at a liquefied natural gas storage LNG.
• the turbine 12 is passed through both the gas intended to feed the low pressure line 4 and the gas intended to feed the production unit 6, c that is, called to be liquefied.
• the thermal integration is performed by a closed loop circuit described below.
• the fluid used may be, by way of non-limiting example, nitrogen or a mixture of hydrocarbons.
• the refrigerant arrives in the compressor C1 by a pipe R1 and leaves through a pipe R2. It then arrives in a first preheating device 10 to heat gas from the pipeline 2 and for supplying the turbine 12 of the pressure lowering station PLD.
• the fluid is then fed via a line R3 to a cooler 22 in order to carry out a control of the temperature of the refrigerant before being returned to the compression unit via a line R4.
• the fluid is then compressed by the second compressor C2, then brought by R5 to the second preheating device 10 before being driven by R6 to a second cooler 22 and to reach by R7 a third compression stage of the second unit. compression.
• a third cooler 22 connected to the third compressor C3 via a line R8 makes it possible to control the temperature of the fluid at the outlet of the compression unit.
• a line R9 leads the refrigerant to a countercurrent exchanger 24 and is then fed by R10 to a pressure reducer 26.
• the latter is mechanically connected to the motor M and the compression unit.
• the fluid is then fed (R1 1) to the condenser 14 of the production unit 6 where it absorbs calories from the portion of natural gas that is desired to be liquefied to obtain liquid natural gas ( LNG).
• the fluid is led (R12) to the desuperheater 18 before reaching by R13 the countercurrent exchanger 24 which is connected downstream to the first compressor C1 of the compression unit.
• the refrigerant fluid is used to achieve a thermal integration between the production unit and the pressure lowering station by recovering in particular the calories released during the compression of the fluid for use in the heating of the gas natural entry PLD pressure lowering station.
• tank 28 which is conventionally used as an expansion tank for the refrigerant.
• FIG. 3 illustrates an alternative embodiment that incorporates certain references of the preceding figures to designate similar elements.
• a pressurized closed water loop or another heat transfer fluid such as a thermal oil
• An air cooler can for example be placed on this line to adjust the cooling capacity at the request of the compression loop.
• a positive displacement pump is used to allow the circulation of the coolant (pressurized water) and an expansion tank can be classically integrated into this circuit.
• FIG. 3 thus recognizes a refrigerant circuit between the compression unit and its three compressors C1, C2 and C3 and the production unit 6. with its condenser 14.
• This circuit is simplified. It passes successively through the three stages of the compression unit and after each stage through a preheating device 10. The refrigerant circuit then passes through the countercurrent exchanger 24 before passing into the expander 26 and then into the condenser 14, reverse the counter-current heat exchanger 24 before returning to the first compression stage and its compressor C1.
• the main difference with the first embodiment of FIG. 2 is that the preheating devices 10 do not directly transfer the calories extracted from the compression stages to the natural gas but to another heat transfer fluid, such as, for example, pressurized water.
• These preheating devices 10 thus form intermediate exchangers.
• a positive displacement pump 142 for circulating the coolant in the corresponding circuit and a cooler 122 to control the temperature of the coolant in this circuit.
• an expansion tank 144 is advantageously integrated with this refrigerant circuit.
• FIG. 4 illustrates a simplified version of the first embodiment illustrated in FIG. 2.
• the references already used to designate similar elements are reused in order to simplify the understanding. reading.
• the compression unit comprises only one stage with a single compressor C.
• the natural gas is then heated in a single preheating device 10 which makes it possible to exchange directly the calories coming from the compressor with the natural gas at the PLD station inlet, upstream of the expansion turbine 12.
• the refrigerant circuit uses for example a mixture of hydrocarbons and nitrogen as heat transfer fluid.
• the latter is compressed by the compressor C driven by the electric motor M (electrically coupled to the generator G of the turbine 12 of the PLD station)
• the fluid is then cooled in contact with the natural gas in the preheating device 10 at the inlet of the the turbine 12 (it should be noted that one could also provide another refrigerant circuit between the preheating device 10 and the natural gas as in the previous figure).
• a cooler 22 or (aero-refrigerant) can be introduced into the circuit to adjust the cooling capacity at the request of the compression loop.
• the heat transfer fluid is then sent through a heat exchanger 214, for example of the PHFE type (acronym for Plate Fin Heat Exchanger or French heat exchanger plates and fins), where
• FIG. 5 also shows a motor M which is used here as an additional energy source (corresponds to WE in FIG. 1) for adjusting the power required for the liquefied gas production unit with the power delivered to the level of the pressure lowering station.
• a motor M which is used here as an additional energy source (corresponds to WE in FIG. 1) for adjusting the power required for the liquefied gas production unit with the power delivered to the level of the pressure lowering station.
• the quantity (mass) of gas passing through the liquefied gas production unit 6 is of the order of 5 to 20. % of the quantity (mass) of gas passing through the PLD pressure lowering station, the rest of the gas (80 to 95%) supplying the pipe 4.
• the systems described above make it possible to perfectly control the production of liquid natural gas.
• the composition of this gas can be controlled. It does not depend on the pressure difference within the pressure lowering station.
• the preheating of the gas at the inlet of the pressure lowering station avoids problems of icing and pipe obstruction.
• Energy recovery is performed at the pressure lowering station, and more precisely at its expansion turbine. This recovery is optimized by passing all the gas flow in this turbine, both the gas that is intended to be expanded in gaseous form and the gas to be liquefied.

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• 2013
  • 2013-02-20 FR FR1300380A patent/FR3002311B1/fr active Active
• 2014
  • 2014-02-20 JP JP2015557507A patent/JP2016513230A/ja active Pending
  • 2014-02-20 MX MX2015010736A patent/MX2015010736A/es unknown
  • 2014-02-20 RU RU2015139854A patent/RU2680285C2/ru active
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  • 2014-02-20 CN CN201480009656.8A patent/CN105209841A/zh active Pending
  • 2014-02-20 ES ES14711813T patent/ES2870082T3/es active Active
  • 2014-02-20 US US14/768,783 patent/US20160003528A1/en not_active Abandoned
  • 2014-02-20 EP EP14711813.7A patent/EP2959242B1/fr active Active
  • 2014-02-20 WO PCT/FR2014/050349 patent/WO2014128408A2/fr active Application Filing

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