US3302416A - Means for maintaining the substitutability of lng - Google Patents

Means for maintaining the substitutability of lng Download PDF

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Publication number
US3302416A
US3302416A US448639A US44863965A US3302416A US 3302416 A US3302416 A US 3302416A US 448639 A US448639 A US 448639A US 44863965 A US44863965 A US 44863965A US 3302416 A US3302416 A US 3302416A
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United States
Prior art keywords
lng
reservoir
pressure
line
heat
Prior art date
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Expired - Lifetime
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US448639A
Inventor
Russell C Proctor
Roger W Parrish
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Conch International Methane Ltd
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Conch International Methane Ltd
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Priority to US448639A priority Critical patent/US3302416A/en
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17CVESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C13/00Details of vessels or of the filling or discharging of vessels
    • F17C13/02Special adaptations of indicating, measuring, or monitoring equipment
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/0002Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the fluid to be liquefied
    • F25J1/0022Hydrocarbons, e.g. natural gas
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/003Processes 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
    • F25J1/0032Processes 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"
    • F25J1/0045Processes 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 vaporising a liquid return stream
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/003Processes 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
    • F25J1/0047Processes 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
    • F25J1/0052Processes 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
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/006Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the refrigerant fluid used
    • F25J1/007Primary atmospheric gases, mixtures thereof
    • F25J1/0072Nitrogen
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/006Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the refrigerant fluid used
    • F25J1/008Hydrocarbons
    • F25J1/0085Ethane; Ethylene
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/006Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the refrigerant fluid used
    • F25J1/008Hydrocarbons
    • F25J1/0087Propane; Propylene
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    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02Processes 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
    • F25J1/0203Processes 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
    • F25J1/0207Processes 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 at least a three level SCR refrigeration cascade
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02Processes 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
    • F25J1/0228Coupling of the liquefaction unit to other units or processes, so-called integrated processes
    • F25J1/0232Coupling 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
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    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02Processes 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
    • F25J1/0243Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0244Operation; Control and regulation; Instrumentation
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02Processes 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
    • F25J1/0243Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0244Operation; Control and regulation; Instrumentation
    • F25J1/0245Different modes, i.e. 'runs', of operation; Process control
    • F25J1/0249Controlling refrigerant inventory, i.e. composition or quantity
    • F25J1/025Details related to the refrigerant production or treatment, e.g. make-up supply from feed gas itself
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    • F17CVESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2221/00Handled fluid, in particular type of fluid
    • F17C2221/03Mixtures
    • F17C2221/032Hydrocarbons
    • F17C2221/033Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG
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    • F17CVESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2223/00Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel
    • F17C2223/01Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel characterised by the phase
    • F17C2223/0146Two-phase
    • F17C2223/0153Liquefied gas, e.g. LPG, GPL
    • F17C2223/0161Liquefied gas, e.g. LPG, GPL cryogenic, e.g. LNG, GNL, PLNG
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    • F17CVESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2223/00Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel
    • F17C2223/03Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel characterised by the pressure level
    • F17C2223/033Small pressure, e.g. for liquefied gas
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    • F17C2225/00Handled fluid after transfer, i.e. state of fluid after transfer from the vessel
    • F17C2225/01Handled fluid after transfer, i.e. state of fluid after transfer from the vessel characterised by the phase
    • F17C2225/0146Two-phase
    • F17C2225/0153Liquefied gas, e.g. LPG, GPL
    • F17C2225/0161Liquefied gas, e.g. LPG, GPL cryogenic, e.g. LNG, GNL, PLNG
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    • F17CVESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2225/00Handled fluid after transfer, i.e. state of fluid after transfer from the vessel
    • F17C2225/01Handled fluid after transfer, i.e. state of fluid after transfer from the vessel characterised by the phase
    • F17C2225/0146Two-phase
    • F17C2225/0153Liquefied gas, e.g. LPG, GPL
    • F17C2225/0169Liquefied gas, e.g. LPG, GPL subcooled
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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    • F17CVESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2225/00Handled fluid after transfer, i.e. state of fluid after transfer from the vessel
    • F17C2225/03Handled fluid after transfer, i.e. state of fluid after transfer from the vessel characterised by the pressure level
    • F17C2225/033Small pressure, e.g. for liquefied gas
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    • F17C2225/00Handled fluid after transfer, i.e. state of fluid after transfer from the vessel
    • F17C2225/04Handled fluid after transfer, i.e. state of fluid after transfer from the vessel characterised by other properties of handled fluid after transfer
    • F17C2225/042Localisation of the filling point
    • F17C2225/043Localisation of the filling point in the gas
    • F17C2225/044Localisation of the filling point in the gas at several points, e.g. with a device for recondensing gas
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    • F17CVESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2227/00Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
    • F17C2227/01Propulsion of the fluid
    • F17C2227/0128Propulsion of the fluid with pumps or compressors
    • F17C2227/0135Pumps
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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    • F17C2227/00Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
    • F17C2227/01Propulsion of the fluid
    • F17C2227/0128Propulsion of the fluid with pumps or compressors
    • F17C2227/0171Arrangement
    • F17C2227/0178Arrangement in the vessel
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    • F17C2227/00Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
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    • F17C2227/0128Propulsion of the fluid with pumps or compressors
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    • F17C2227/00Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
    • F17C2227/03Heat exchange with the fluid
    • F17C2227/0337Heat exchange with the fluid by cooling
    • F17C2227/0341Heat exchange with the fluid by cooling using another fluid
    • F17C2227/0355Heat exchange with the fluid by cooling using another fluid in a closed loop
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    • F17C2227/00Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
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    • F17C2265/00Effects achieved by gas storage or gas handling
    • F17C2265/03Treating the boil-off
    • F17C2265/032Treating the boil-off by recovery
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    • F17C2265/035Treating the boil-off by recovery with cooling with subcooling the liquid phase
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    • F25J2230/00Processes or apparatus involving steps for increasing the pressure of gaseous process streams
    • F25J2230/32Compression of the product stream
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    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2230/00Processes or apparatus involving steps for increasing the pressure of gaseous process streams
    • F25J2230/60Processes or apparatus involving steps for increasing the pressure of gaseous process streams the fluid being hydrocarbons or a mixture of hydrocarbons
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    • F25J2235/00Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams
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    • F25J2245/00Processes or apparatus involving steps for recycling of process streams
    • F25J2245/90Processes or apparatus involving steps for recycling of process streams the recycled stream being boil-off gas from storage
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2290/00Other details not covered by groups F25J2200/00 - F25J2280/00
    • F25J2290/34Details about subcooling of liquids
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2290/00Other details not covered by groups F25J2200/00 - F25J2280/00
    • F25J2290/62Details of storing a fluid in a tank

Definitions

  • LNG is a mixture of hydrocarbon gases, all of which have varied boiling points. Under conditions of ordinary storage in a tank, from which some of the product is allowed to boil off, fractionation of the mixture of the gases takes place in the storage tank, clue to these difierent boiling points.
  • the higher boiling point constit uents vaporize less readily than those of lower boiling point, which produces a boil-off product having a lower B.t.u. content and a diiferent composition from the liquid inventory remaining in the tank.
  • the substitutability of the gas is measured by the lifting limit, flash-back limit and yellow tip limit, which factors are defined by the A.G.A. as the principal factors in determining the substitutability of a gas.
  • the present invention has for its major object to maintain the substitutability of a product which is stored prior to use in liquid form at substantially atmospheric pressure, as a mixture of liquid gases of which the constituents have different boiling points.
  • a major object of the invention is to add refrigeration (i.e., remove heat) from the stored liquid gases in a highly efficient manner and at a relatively low cost both in energy and in equipment.
  • the above and other objects are accomplished by providing a refrigeration source, external to the stored gases, subcooling limited amounts of the stored liquid gas from selected locations of a storage volume sufiicient to make up the heat leakage into the system, and returning said subcooled liquid to preferred locations of the storage space in such manner as to provide relatively uniform temperature conditions throughout the stored liquid with minimum disturbance of the stratified vapors above the liquid surface.
  • a refrigeration source external to the stored gases, subcooling limited amounts of the stored liquid gas from selected locations of a storage volume sufiicient to make up the heat leakage into the system, and returning said subcooled liquid to preferred locations of the storage space in such manner as to provide relatively uniform temperature conditions throughout the stored liquid with minimum disturbance of the stratified vapors above the liquid surface.
  • liquid is withdrawn from the storage reservoir from a region near the bottom of the reservoir, the withdrawn liquid is subcooled, and the liquid is returned to the main liquid body in such fashion as to maintain the temperature of the liquid substantially uniform throughout its volume and at a level such that no boiloff can occur.
  • Another feature of the invention resides in effecting the makeup refrigeration in the vapor space of the tank for maximum efliciency.
  • the total volume of liquid is not subcooled, but is maintained at equilibrium temperature at substantially ambient atmospheric pressure, so that the difference between the external and internal pressures on the storage reservoir are reduced to a minimum.
  • Another advantage of the invention is that the necessary 3,302,416 Patented Feb. 7, 1967 heat exchange is accomplished between liquids rather than gases, which reduces the time lag and permits closer temperature control.
  • Still another advantage is the elimination of the vapor return line from the tank, which is an expensive line, and must be very long, usually in the order of 250-300 feet, for reasons of established code clearances.
  • an N -LNG subcooler is employed to subcool the LNG in an amount normally sufiicient to make up for the heat leak into the tank while inventory is being added to the tank.
  • an amount of subcooled make (input liquid) is diverted through a subcooler inside the storage tank, where it is heat exchanged with an amount of inventory piped through the subcooler.
  • the sub-cooled inventory is preferably returned below the liquid level under normal operation, in order to maintain nearly uniform temperature conditions throughout the stored liquid; however, if more immediate response is needed to a rising pressure in the tank, means are provided for diverting the sub-cooled liquid through a valve and spraying it into the vapor space to more abruptly reduce the pressure within the tank.
  • FIG. 1 is a schematic flow chart showing the principle of the invention
  • FIG. 2 is a schematic sectional view of a novel subcooler intended for use within the LNG reservoir.
  • FIG. 3 is a flow chart of a modified system according to the invention.
  • LNG is supplied as high-pressure feed gas on line 2, and is liquefied prior to storage by means of several heat exchange steps, which may be conventional, and which are shown in general fashion as a C (propane) loop 3, a C (ethane, ethylene) loop 4, a C (methane) heat-exchange step 6 at distribution pressure, and a C (methane) heat-exchange step 7 at atmospheric pressure, since the fluid is stored in tank 8 at atmospheric pressure.
  • a portion of the input is diverted on line 9, through valve 11, and supplied through the preceding heat-exchange steps in reverse, directly to the low pressure distribution line 12. This is done in order to take advantage of the reduction of pressure in valve 11, with its resultant refrigeration effect.
  • An additional portion Olf the input is diverted on line 10 through valve '15 and supplied through the heat-exchange steps in reverse to a compressor 20 which compresses this gas to the pressure in the low pressure distribution line 12.
  • the product in line 2 is then passed through line 13 and a further pressure reduction valve 14 into storage with a small flash to atmospheric pressure.
  • a major advantage of storing the fluid at atmospheric pressure is that the storage reservoir 8 need not be built to withstand any gas pressure either internal or external, which would be very difficult to do with the large tanks used for this purpose, often over feet in diameter.
  • the vapor pressure in the tank is maintained very slightly above atmospheric, to avoid any danger of air entering the vapor space and producing a dangerous mixture.
  • a vent line is usually employed, and upon any rise in pressure due to heat leakage into the tank, the excess vapor is simply vented off to be reliquefied or used as fuel after compression.
  • a nitrogen refrigeration circuit is employed, the nitrogen in line 16 being compressed to a suitable pressure by means of compressor 17, cooled in intercooler 18, and passed in line 19 through the heat exchangers 3, 4, 6 and 7 as previously shown.
  • the nitrogen emerges on line 21 at 248 F. and 300 p.s.i.a., is passed through a pressure reduction valve 22 to line 23, and thence to coil 24 of a special sub-cooler unit, and thence back to line 26 and the respective heat exchangers back to line 16, where it is recycled through compressor 17.
  • Subcooler 25 is supplied with LNG from near the bottom of the reservoir through pump 27 and line 28.
  • the sub-cooled inventory emerges on line 29 and is delivered, preferably near the central portion of the fluid in the tank on line 35, which may be a tangential nozzle, or a series of nozzles, in order to ensure fairly thorough mixing of the sub-cooled liquid with the liquid in the tank, the amount of sub-cooled liquid thus supplied being regulated so as to maintain the desired equilibrium conditions in the tank.
  • This can be done in any suitable or known manner, and is indicated generally by the provision of a pressure control device 33, responsive to the pressure in the tank to control the valve 22 through control line 34.
  • a cylinder of nitrogen under pressure, 41 is used to supply makeup nitrogen through valve 42 to the nitrogen refrigeration cycle as needed.
  • the stored gas contains an appreciable amount of nitrogen, since this has a lower boiling point than the other constituents of the LNG, the vapor in the tank will be very rich in nitrogen, and advantage can be taken of this by using this vapor on line 43, controlled by valve 44, as an alternative source of makeup gas.
  • the system is the same as shown in FIG. 1 down to exchanger 7, but at this point, the nitrogen line 16 is passed through the N -LNG heat exchanger 57, then through another heat exchanger 51, which serves as an N LNG subcooler for supplying subcooled LNG on line 52 to the tank through valve 53 and through line 61 to subcooler unit 25', which corresponds in function to subcooler unit 25 of FIG.
  • Subcooler 25' is supplied with inventory (LNG) from a point near the bottom of the tank, through pump 27 and line 28, and the LNG, after being suitably subcooled, emerges on line 29 and is normally passed by valve 31 to line 32, which terminates preferably near the midpoint of the reservoir, usually in a tangential nozzle so that the subcooled LNG may be very thoroughly mixed with the main body of the liquid, thereby providing sufficient rerigeration to exactly offset normal heat leakage into the tank, and to maintain the mass of LNG in the reservoir at equilibrium temperature corresponding to atmospheric pressure.
  • This condition is automatically maintained by means of a pressure control unit 33, which through control line 34 controls valve 36 to provide additional refrigeration if the pressure rises, and vice versa.
  • an additional control line 37 is provided to operate on valve 31 to divert the subcooled inventory from line 29 through line 38 to a number of spray nozzles 39 to quickly reduce the temperature of the vapor in the reservoir and thus maintain its pressure at the safe level. Since this last operation is less desirable than providing the fluid directly to the main body of the reservoir via line 32, it is not normally employed. It is particularly important to note that the above system enables the entire body of liquid to be maintained at substantially equilibrium temperature at atmospheric pressure. If the liquid were to be sub-cooled, then the vapor pressure within the reservoir would be less than atmospheric, and the reservoir, and particularly its roof, would have to be built sufficiently strong to withstand this inward pressure, which would require a much more expensive structure.
  • the system of FIG. 3 does not employ the nitrogen directly in the subcooler 25', but that the coil 24 uses instead subcooled LNG which is brought to the desired low temperature by heat exchange with the nitrogen refrigeration system.
  • the subcooler 25 is not normally employed during periods when the tank is in use, that is, when inventory is being constantly supplied; during such periods, the desired equilibrium conditions can be maintained by subcooling the make in subcooler 51, from which it emerges on line 52 at the desired low temperature, and is passed through valve 53 into the storage reservoir tank 8 at a temperature sufficiently low to make up for a normal heat leakage into the tank, and to maintain the desired equilibrium conditions.
  • valve 54 which is normally closed, is opened, and normally open valve 53 is closed, thus establishing a LNG circuit through subcooler 25', line 57, and N -LNG exchanger 57, line 58, through exchangers 7, 6, 4 and 3 to the distribution line.
  • Subcooler 25' operates similarly to subcooler 25 of FIG. 1, except that its coil uses LNG instead of nitrogen gas directly.
  • the stages preceding exchanger 57 can be exactly the same as those shown in FIG. 1.
  • the primary advantage to this system is in eliminating the large vapor line between the storage and the liquefaction plant and substituting a much smaller liquid line 57.
  • System for maintaining the substitutability of LNG comprising (a) a large-scale storage reservoir for LNG having a vapor space near the top thereof,
  • (e) means for returning the subcooled Withdrawn LNG to the body of LNG in the reservoir at a rate sufficient to offset heat leakage into the reservoir and to maintain equilibrium conditions in the res ervoir so as to prevent boil-off.
  • heat-exchange means for subcooling the natural gas with N such that the input to said reservoir is at a temperature sufficient to olfset heat leakage into the reservoir and prevent boil-off or increase in pressure in the vapor space above the liquid during periods when the reservoir is being supplied with input
  • (h) means for withdrawing LNG from a point near the lower portion of the reservoir and passing it through said heat-exchange unit to cool the withdrawn LNG
  • said means for returning the subcooled withdrawn LNG to the body of LNG including, means for delivering the subcooled LNG to a region of the reservoir approximately midway between the top and bottom of the reservoir.

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Description

ch. 7,, 196? Ramos-r012 ETAL 3,302,413
MEANS FUR MAINTAINING THE SUBSTITUTABILITY OF LNG 2 Sheets-Sheet 1 Filed April 16, 1965 High Pressure l2 l w Low Pressure Disfribufion Line 9 Ill 1 Q "2 F A I m w e v w 7 4 W 6 5 6 s Ar A% D.. 4 er! 3 9p nr mm M b MD 3 L X% 3 EN m P IT 0 9 CA N N Cylinder For Make-Up Alrerncng Make-Up m m m m Russell C.Procfor Roger W. Parrish ATTORNEY Feb. 7, 1967 R. c. PROCTOR ETAL 3,302,416
MEANS FOR MAINTAINING THE SUBSTITUTABILITY 0F LNG Filed April 16, 1965 2 Sheets-Sheet 2 Distribution me LNG" Feed Gas 1 '1 g l p u J I l N compressor g l 0 Exchange w.
l I I Cg Exchange 0, Exchange At Distribui'ion Pressure IE LI 0 Exchange A'r Afi'rnospheric Pressure 58 9 19. LNG
WILCOHTYOI Line 59 N -LNG k Exchanger 5i LIV -LNG Subcooler INVENTORS Russel! C Proctor Roger W. Parrish BY j hg ATTORNEY United States Patent 3,302,416 MEANS FOR MAINTAINING THE SUBSTITUT- ABILITY OF LNG Russell C. Proctor, Leawood, Kans., and Roger W. Parrish, Independence, Mo., assignors to Conch International Methane Limited, Nassau, Bahamas, a Bahamian company Filed Apr. 16, 1965, Ser. No. 448,639 8 Claims. (CI. 62-45) This invention relates to a system for storing LNG (liquid natural gas) in such a manner as to maintain its substitutability. LNG is a mixture of hydrocarbon gases, all of which have varied boiling points. Under conditions of ordinary storage in a tank, from which some of the product is allowed to boil off, fractionation of the mixture of the gases takes place in the storage tank, clue to these difierent boiling points. The higher boiling point constit=uents vaporize less readily than those of lower boiling point, which produces a boil-off product having a lower B.t.u. content and a diiferent composition from the liquid inventory remaining in the tank.
It is possible, by means of some schemes which have been proposed, to make up for the above effect by manipulating the gas fractions so that the product has a constant B.t.u.- However, this is not suflieient for many customers who .require that the gas be substitutable. The substitutability of the gas is measured by the lifting limit, flash-back limit and yellow tip limit, which factors are defined by the A.G.A. as the principal factors in determining the substitutability of a gas. The present invention has for its major object to maintain the substitutability of a product which is stored prior to use in liquid form at substantially atmospheric pressure, as a mixture of liquid gases of which the constituents have different boiling points. This is accomplished, according to the invention, primarily by adding sufiicient refrigeration to the stored liquid gases to equal the heat leak into storage and thereby prohibit any boiloif at all from occurring. Without boiloff, there can be no composition change, therefore the liquefied natural gases remain completely substitutable with pipeline gas, since they have the same composition.
A major object of the invention is to add refrigeration (i.e., remove heat) from the stored liquid gases in a highly efficient manner and at a relatively low cost both in energy and in equipment.
According to the present invention, the above and other objects are accomplished by providing a refrigeration source, external to the stored gases, subcooling limited amounts of the stored liquid gas from selected locations of a storage volume sufiicient to make up the heat leakage into the system, and returning said subcooled liquid to preferred locations of the storage space in such manner as to provide relatively uniform temperature conditions throughout the stored liquid with minimum disturbance of the stratified vapors above the liquid surface. More specifically, in a preferred form of the invention, liquid is withdrawn from the storage reservoir from a region near the bottom of the reservoir, the withdrawn liquid is subcooled, and the liquid is returned to the main liquid body in such fashion as to maintain the temperature of the liquid substantially uniform throughout its volume and at a level such that no boiloff can occur. Another feature of the invention resides in effecting the makeup refrigeration in the vapor space of the tank for maximum efliciency. According to the invention, the total volume of liquid is not subcooled, but is maintained at equilibrium temperature at substantially ambient atmospheric pressure, so that the difference between the external and internal pressures on the storage reservoir are reduced to a minimum.
Another advantage of the invention is that the necessary 3,302,416 Patented Feb. 7, 1967 heat exchange is accomplished between liquids rather than gases, which reduces the time lag and permits closer temperature control.
Still another advantage is the elimination of the vapor return line from the tank, which is an expensive line, and must be very long, usually in the order of 250-300 feet, for reasons of established code clearances.
The major objects of the invention are accomplished by subcooling selected portions of the LNG by heat exchange against nitrogen. In one form, an N -LNG subcooler is employed to subcool the LNG in an amount normally sufiicient to make up for the heat leak into the tank while inventory is being added to the tank. However, during periods of holding, when the tank is full and no inventory is being added, an amount of subcooled make (input liquid) is diverted through a subcooler inside the storage tank, where it is heat exchanged with an amount of inventory piped through the subcooler. In accordance with the invention, the sub-cooled inventory is preferably returned below the liquid level under normal operation, in order to maintain nearly uniform temperature conditions throughout the stored liquid; however, if more immediate response is needed to a rising pressure in the tank, means are provided for diverting the sub-cooled liquid through a valve and spraying it into the vapor space to more abruptly reduce the pressure within the tank.
The specific nature of the invention, as well as other objects and advantages thereof, will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings, in which:
FIG. 1 is a schematic flow chart showing the principle of the invention;
FIG. 2 is a schematic sectional view of a novel subcooler intended for use Within the LNG reservoir; and
FIG. 3 is a flow chart of a modified system according to the invention.
Referring to FIG. 1, LNG is supplied as high-pressure feed gas on line 2, and is liquefied prior to storage by means of several heat exchange steps, which may be conventional, and which are shown in general fashion as a C (propane) loop 3, a C (ethane, ethylene) loop 4, a C (methane) heat-exchange step 6 at distribution pressure, and a C (methane) heat-exchange step 7 at atmospheric pressure, since the fluid is stored in tank 8 at atmospheric pressure. A portion of the input is diverted on line 9, through valve 11, and supplied through the preceding heat-exchange steps in reverse, directly to the low pressure distribution line 12. This is done in order to take advantage of the reduction of pressure in valve 11, with its resultant refrigeration effect. An additional portion Olf the input is diverted on line 10 through valve '15 and supplied through the heat-exchange steps in reverse to a compressor 20 which compresses this gas to the pressure in the low pressure distribution line 12. The product in line 2 is then passed through line 13 and a further pressure reduction valve 14 into storage with a small flash to atmospheric pressure. A major advantage of storing the fluid at atmospheric pressure, as is well known, is that the storage reservoir 8 need not be built to withstand any gas pressure either internal or external, which would be very difficult to do with the large tanks used for this purpose, often over feet in diameter. In usual practice, the vapor pressure in the tank is maintained very slightly above atmospheric, to avoid any danger of air entering the vapor space and producing a dangerous mixture. For this purpose, a vent line is usually employed, and upon any rise in pressure due to heat leakage into the tank, the excess vapor is simply vented off to be reliquefied or used as fuel after compression.
In order to provide the necessary refrigeration to offset heat loss in the tank, and eliminate handling these low pressure vapors, a nitrogen refrigeration circuit is employed, the nitrogen in line 16 being compressed to a suitable pressure by means of compressor 17, cooled in intercooler 18, and passed in line 19 through the heat exchangers 3, 4, 6 and 7 as previously shown. The nitrogen emerges on line 21 at 248 F. and 300 p.s.i.a., is passed through a pressure reduction valve 22 to line 23, and thence to coil 24 of a special sub-cooler unit, and thence back to line 26 and the respective heat exchangers back to line 16, where it is recycled through compressor 17.
Subcooler 25 is supplied with LNG from near the bottom of the reservoir through pump 27 and line 28. The sub-cooled inventory emerges on line 29 and is delivered, preferably near the central portion of the fluid in the tank on line 35, which may be a tangential nozzle, or a series of nozzles, in order to ensure fairly thorough mixing of the sub-cooled liquid with the liquid in the tank, the amount of sub-cooled liquid thus supplied being regulated so as to maintain the desired equilibrium conditions in the tank. This can be done in any suitable or known manner, and is indicated generally by the provision of a pressure control device 33, responsive to the pressure in the tank to control the valve 22 through control line 34.
A cylinder of nitrogen under pressure, 41, is used to supply makeup nitrogen through valve 42 to the nitrogen refrigeration cycle as needed. However, when the stored gas contains an appreciable amount of nitrogen, since this has a lower boiling point than the other constituents of the LNG, the vapor in the tank will be very rich in nitrogen, and advantage can be taken of this by using this vapor on line 43, controlled by valve 44, as an alternative source of makeup gas.
Referring to FIG. 3, the system is the same as shown in FIG. 1 down to exchanger 7, but at this point, the nitrogen line 16 is passed through the N -LNG heat exchanger 57, then through another heat exchanger 51, which serves as an N LNG subcooler for supplying subcooled LNG on line 52 to the tank through valve 53 and through line 61 to subcooler unit 25', which corresponds in function to subcooler unit 25 of FIG. 1, except that its cooling coil 24' contains subcooled LNG instead of N Subcooler 25' is supplied with inventory (LNG) from a point near the bottom of the tank, through pump 27 and line 28, and the LNG, after being suitably subcooled, emerges on line 29 and is normally passed by valve 31 to line 32, which terminates preferably near the midpoint of the reservoir, usually in a tangential nozzle so that the subcooled LNG may be very thoroughly mixed with the main body of the liquid, thereby providing sufficient rerigeration to exactly offset normal heat leakage into the tank, and to maintain the mass of LNG in the reservoir at equilibrium temperature corresponding to atmospheric pressure. This condition is automatically maintained by means of a pressure control unit 33, which through control line 34 controls valve 36 to provide additional refrigeration if the pressure rises, and vice versa. If for any reason the pressure rise should be too rapid and the pressure tend to rise to an undesired point, an additional control line 37 is provided to operate on valve 31 to divert the subcooled inventory from line 29 through line 38 to a number of spray nozzles 39 to quickly reduce the temperature of the vapor in the reservoir and thus maintain its pressure at the safe level. Since this last operation is less desirable than providing the fluid directly to the main body of the reservoir via line 32, it is not normally employed. It is particularly important to note that the above system enables the entire body of liquid to be maintained at substantially equilibrium temperature at atmospheric pressure. If the liquid were to be sub-cooled, then the vapor pressure within the reservoir would be less than atmospheric, and the reservoir, and particularly its roof, would have to be built sufficiently strong to withstand this inward pressure, which would require a much more expensive structure.
It will be noted that the system of FIG. 3 does not employ the nitrogen directly in the subcooler 25', but that the coil 24 uses instead subcooled LNG which is brought to the desired low temperature by heat exchange with the nitrogen refrigeration system. The subcooler 25 is not normally employed during periods when the tank is in use, that is, when inventory is being constantly supplied; during such periods, the desired equilibrium conditions can be maintained by subcooling the make in subcooler 51, from which it emerges on line 52 at the desired low temperature, and is passed through valve 53 into the storage reservoir tank 8 at a temperature sufficiently low to make up for a normal heat leakage into the tank, and to maintain the desired equilibrium conditions. However, when the tank is used to store LNG for extended periods, the equilibrium conditions cannot be maintained by this means, since at such times there can be no input into the tank if the tank is full. When this condition occurs, valve 54, which is normally closed, is opened, and normally open valve 53 is closed, thus establishing a LNG circuit through subcooler 25', line 57, and N -LNG exchanger 57, line 58, through exchangers 7, 6, 4 and 3 to the distribution line. Subcooler 25' operates similarly to subcooler 25 of FIG. 1, except that its coil uses LNG instead of nitrogen gas directly. The stages preceding exchanger 57 can be exactly the same as those shown in FIG. 1.
The primary advantage to this system is in eliminating the large vapor line between the storage and the liquefaction plant and substituting a much smaller liquid line 57.
It will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction and arrangement Within the scope of our invention as defined in the appended claims.
We claim:
1. System for maintaining the substitutability of LNG comprising (a) a large-scale storage reservoir for LNG having a vapor space near the top thereof,
(b) means for supplying LNG to said reservoir for storage at substantially atmospheric pressure,
(c) a heat-exchange unit in said vapor space, said unit having a supply of refrigerant external to the reservoir at a lower temperature than the stored LNG,
(d) means for withdrawing LNG from a point near the bottom of the reservoir and passing it through said heat-exchange unit to subcool the withdrawn LNG,
(e) means for returning the subcooled Withdrawn LNG to the body of LNG in the reservoir at a rate sufficient to offset heat leakage into the reservoir and to maintain equilibrium conditions in the res ervoir so as to prevent boil-off.
2. The invention according to claim 1, wherein said external refrigerant is N 3. System for maintaining the substitutabilty of LNG comprising (a) a large-scale storage reservoir for LNG having a vapor space near the top thereof,
(-b) a high-pressure line for supplying natural gas,
(c) multi-refrigerant means for reducing the temperature of said gas,
(d) means for reducing the pressure of said natural gas and supplying it to said reservoir in liquefied form as LNG at substantially atmospheric pressure,
(e) a nitrogen refrigeration circuit for subcooling the supplied LNG to a lower temperature than the LNG in said reservoir,
(f) heat-exchange means for subcooling the natural gas with N such that the input to said reservoir is at a temperature sufficient to olfset heat leakage into the reservoir and prevent boil-off or increase in pressure in the vapor space above the liquid during periods when the reservoir is being supplied with input,
(g) a heat-exchange unit in said vapor space, and
means for supplying said unit with subcooled refrigerant from said refrigeration circuit,
(h) means for withdrawing LNG from a point near the lower portion of the reservoir and passing it through said heat-exchange unit to cool the withdrawn LNG,
(i) means for returning the cooled withdrawn LNG to the body of LNG in the reservoir at a rate sufficient to offset heat leakage into the reservoir and maintain equilibrium conditions in the reservoir so as to prevent boil-oft or increase in tank pressure during periods when no input is supplied to the reservoir.
4. The invention according to claim 3, and pressurecontrol means for controlling the operation of said heatexchange unit so as to maintain the pressure in the tank at-a point above atmospheric pressure but within the design pressure of the tank.
5. The invention according to claim 3, and pressurecontrol means for controlling the operation of the LNG subcooler and the temperature of the input to the reservoir so as to maintain the pressure in the tank above atmospheric pressure but within the design pressure of the tank.
6. The invention according to claim 3, including additional means for spraying subcooled LNG into the vapor space of the reservoir, and pressure-controlled means for activating said last additional means only upon an excessive rise in pressure in the vapor space so as to rapidly reduce and control the pressure in the vapor space.
7. The invention according to claim 1, said means for returning the subcooled withdrawn LNG to the body of LNG including, means for delivering the subcooled LNG to a region of the reservoir approximately midway between the top and bottom of the reservoir.
8. System for maintaining the substitutability of LNG comprising (a) a large-scale storage reservoir for LNG having a vapor space near the top thereof,
(b) means for supplying LNG to said reservoir for storage at substantially atmospheric pressure,
(c) a heat-exchange unit in said vapor space, said unit having a supply of external N refrigerant at a lower temperature than the stored LNG,
(d) means for withdrawing LNG from a point near the bottom of the reservoir and passing it through said heat-exchange unit to subcool the withdrawn LNG,
(e) means for returning the subcooled withdrawn LNG to the body of LNG in the reservoir at a rate sufiicient to oiTset heat leakage into the reservoir and to maintain equilibrium conditions in the reservoir so as to prevent boil-off,
(f) and means for adding N -rich gas from said vapor space to said external refrigerant as make-up gas, when the feed stock contains a high percentage of N References Cited by the Examiner UNITED STATES PATENTS 2,263,864 11/1941 Avigdor 62-45 X 2,682,154 6/1954 Wilkinson 6254 2,753,691 7/1956 Wissrniller -62-54 2,784,560 3/1957 Johnson 62--54 2,959,928 11/1960 Maker 62-54 2,960,837 11/1960 Swenson et a1. 62-45 X LLOYD L. KING, Primary Examiner.

Claims (1)

1. SYSTEM FOR MAINTAINING THE SUBSTITUTABILITY OF LNG COMPRISING (A) A LARGE-SCALE STORAGE RESERVOIR FOR LNG HAVING A VAPOR SPACE NEAR THE TOP THEREOF, (B) MEANS FOR SUPPLYING LNG TO SAID RESERVOIR FOR STORAGE AT SUBSTANTIALLY ATMOSPHERIC PRESSURE, (C) A HEAT-EXCHANGE UNIT IN SAID VAPOR SPACE, SAID UNIT HAVING A SUPPLY OF REFRIGERANT EXTERNAL TO THE RESERVOIR AT A LOWER TEMPERATURE THAN THTE STORED LNG, (D) MEANS FOR WITHDRAWING LNG FROM A POINT NEAR THE BOTTOM OF THE RESERVOIR AND PASSIN IT THROUGH SAID HEAT-EXCHANGE UNIT TO SUBCOOL THE WITHDRAWN LNG, (E) MEANS FOR RETURNING THE SUBCOOLED WITHDRAWN LNG TO THE BODY OF LNG IN THE RESERVOIR AT A RATE SUFFICIENT TO OFFSET HEAT LEAKAGE INTO THE RESERVOIR AND TO MAINTAIN EQUILIBRIUM CONDITIONS IN THE RESERVOIR SO AS TO PREVENT BOIL-OFF.
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Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3371497A (en) * 1966-08-05 1968-03-05 Air Prod & Chem Maintaining constant composition in a volatile multi-component liquid
US3375675A (en) * 1965-07-16 1968-04-02 Sulzer Ag Low temperature refrigerating apparatus
US3400547A (en) * 1966-11-02 1968-09-10 Williams Process for liquefaction of natural gas and transportation by marine vessel
US3453836A (en) * 1967-07-24 1969-07-08 Mcmullen John J Liquefied petroleum gas tanker
US3661542A (en) * 1969-01-23 1972-05-09 Shell Oil Co Short term peak shaving of natural gas
US3792590A (en) * 1970-12-21 1974-02-19 Airco Inc Liquefaction of natural gas
US3837821A (en) * 1969-06-30 1974-09-24 Air Liquide Elevating natural gas with reduced calorific value to distribution pressure
US3857251A (en) * 1971-12-27 1974-12-31 Technigaz Lng storage tank vapor recovery by nitrogen cycle refrigeration with refrigeration make-up provided by separation of same vapor
US3894856A (en) * 1969-07-22 1975-07-15 Airco Inc Liquefaction of natural gas with product used as adsorber
US4296610A (en) * 1980-04-17 1981-10-27 Union Carbide Corporation Liquid cryogen delivery system
US4727723A (en) * 1987-06-24 1988-03-01 The M. W. Kellogg Company Method for sub-cooling a normally gaseous hydrocarbon mixture
DE19716415C1 (en) * 1997-04-18 1998-10-22 Linde Ag Process for liquefying a hydrocarbon-rich stream
ES2179717A1 (en) * 1998-10-23 2003-01-16 Gaz Transport & Technigaz Process and system for preventing the evaporation of a liquefied gas
US20070130962A1 (en) * 2005-12-12 2007-06-14 Blalock Clayton E System and Method for Storing Cryogenic Liquid Air
US20090100844A1 (en) * 2003-11-13 2009-04-23 Hamworthy Gas Systems As Apparatus and method for controlling temperature in a boil-off gas
US20090260392A1 (en) * 2008-04-17 2009-10-22 Linde Aktiengesellschaft Method of liquefying a hydrocarbon-rich fraction
US20120000242A1 (en) * 2010-04-22 2012-01-05 Baudat Ned P Method and apparatus for storing liquefied natural gas
US20130174583A1 (en) * 2012-01-06 2013-07-11 Ron C. Lee Methods for storing cryogenic fluids in storage vessels
US20150000334A1 (en) * 2013-07-01 2015-01-01 Houlder Limited Liquefaction of Natural Gas
US20150219280A1 (en) * 2014-02-05 2015-08-06 Air Liquide Industrial U.S. Lp Method and apparatus for reducing boil-off gas losses from a liquid storage tank
US9395048B1 (en) * 2010-07-13 2016-07-19 The Boeing Company Thermally protected liquid acquisition device for cryogenic fluids
FR3055692A1 (en) * 2016-09-06 2018-03-09 Air Liquide INSTALLATION, METHOD FOR STORING AND RELICITING LIQUEFIED GAS AND ASSOCIATED TRANSPORT VEHICLE
WO2018091413A1 (en) 2016-11-15 2018-05-24 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Boil off gas recondenser and lng supply system equipped with the boil off gas recondenser
US20210231366A1 (en) * 2020-01-23 2021-07-29 Air Products And Chemicals, Inc. System and method for recondensing boil-off gas from a liquefied natural gas tank
WO2021209231A1 (en) 2020-04-17 2021-10-21 L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Liquefied gas storage facility
US11698169B2 (en) 2016-12-23 2023-07-11 Shell Usa, Inc. Vessel for the transport of liquefied gas and method of operating the vessel

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US2682154A (en) * 1949-06-21 1954-06-29 Air Reduction Storage of liquefied gases
US2753691A (en) * 1951-09-15 1956-07-10 Chicago Bridge & Iron Co Method of cooling and storing propane and the like
US2784560A (en) * 1954-02-11 1957-03-12 American Messer Corp Process and apparatus for storing and shipping liquefied gases
US2959928A (en) * 1957-09-26 1960-11-15 California Research Corp Lpg tankship refrigeration system
US2960837A (en) * 1958-07-16 1960-11-22 Conch Int Methane Ltd Liquefying natural gas with low pressure refrigerants

Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3375675A (en) * 1965-07-16 1968-04-02 Sulzer Ag Low temperature refrigerating apparatus
US3371497A (en) * 1966-08-05 1968-03-05 Air Prod & Chem Maintaining constant composition in a volatile multi-component liquid
US3400547A (en) * 1966-11-02 1968-09-10 Williams Process for liquefaction of natural gas and transportation by marine vessel
US3453836A (en) * 1967-07-24 1969-07-08 Mcmullen John J Liquefied petroleum gas tanker
US3661542A (en) * 1969-01-23 1972-05-09 Shell Oil Co Short term peak shaving of natural gas
US3837821A (en) * 1969-06-30 1974-09-24 Air Liquide Elevating natural gas with reduced calorific value to distribution pressure
US3894856A (en) * 1969-07-22 1975-07-15 Airco Inc Liquefaction of natural gas with product used as adsorber
US3792590A (en) * 1970-12-21 1974-02-19 Airco Inc Liquefaction of natural gas
US3857251A (en) * 1971-12-27 1974-12-31 Technigaz Lng storage tank vapor recovery by nitrogen cycle refrigeration with refrigeration make-up provided by separation of same vapor
US4296610A (en) * 1980-04-17 1981-10-27 Union Carbide Corporation Liquid cryogen delivery system
US4727723A (en) * 1987-06-24 1988-03-01 The M. W. Kellogg Company Method for sub-cooling a normally gaseous hydrocarbon mixture
DE19716415C1 (en) * 1997-04-18 1998-10-22 Linde Ag Process for liquefying a hydrocarbon-rich stream
ES2179717A1 (en) * 1998-10-23 2003-01-16 Gaz Transport & Technigaz Process and system for preventing the evaporation of a liquefied gas
US20090100844A1 (en) * 2003-11-13 2009-04-23 Hamworthy Gas Systems As Apparatus and method for controlling temperature in a boil-off gas
US20070130962A1 (en) * 2005-12-12 2007-06-14 Blalock Clayton E System and Method for Storing Cryogenic Liquid Air
US20090260392A1 (en) * 2008-04-17 2009-10-22 Linde Aktiengesellschaft Method of liquefying a hydrocarbon-rich fraction
US20120000242A1 (en) * 2010-04-22 2012-01-05 Baudat Ned P Method and apparatus for storing liquefied natural gas
US9395048B1 (en) * 2010-07-13 2016-07-19 The Boeing Company Thermally protected liquid acquisition device for cryogenic fluids
US20130174583A1 (en) * 2012-01-06 2013-07-11 Ron C. Lee Methods for storing cryogenic fluids in storage vessels
CN104136868A (en) * 2012-01-06 2014-11-05 琳德股份公司 Methods for storing cryogenic fluids in storage vessels
US20150000334A1 (en) * 2013-07-01 2015-01-01 Houlder Limited Liquefaction of Natural Gas
US20150219280A1 (en) * 2014-02-05 2015-08-06 Air Liquide Industrial U.S. Lp Method and apparatus for reducing boil-off gas losses from a liquid storage tank
KR20190044108A (en) * 2016-09-06 2019-04-29 레르 리키드 쏘시에떼 아노님 뿌르 레?드 에렉스뿔라따시옹 데 프로세데 조르즈 클로드 Facilities, methods and associated transport vehicles for storing and liquefying liquefied gases
WO2018046809A1 (en) 2016-09-06 2018-03-15 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Facility, method for storing and liquefying a liquefied gas and associated transport vehicle
FR3055692A1 (en) * 2016-09-06 2018-03-09 Air Liquide INSTALLATION, METHOD FOR STORING AND RELICITING LIQUEFIED GAS AND ASSOCIATED TRANSPORT VEHICLE
CN109906337A (en) * 2016-09-06 2019-06-18 乔治洛德方法研究和开发液化空气有限公司 For the facility for the liquefied gas that stores and liquefy, method and relevant means of transport
CN109906337B (en) * 2016-09-06 2021-08-17 乔治洛德方法研究和开发液化空气有限公司 Installation, method for storing and liquefying liquefied gas and associated transport means
US11549646B2 (en) * 2016-09-06 2023-01-10 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Facility, method for storing and liquefying a liquefied gas and associated transport vehicle
WO2018091413A1 (en) 2016-11-15 2018-05-24 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Boil off gas recondenser and lng supply system equipped with the boil off gas recondenser
US11698169B2 (en) 2016-12-23 2023-07-11 Shell Usa, Inc. Vessel for the transport of liquefied gas and method of operating the vessel
US20210231366A1 (en) * 2020-01-23 2021-07-29 Air Products And Chemicals, Inc. System and method for recondensing boil-off gas from a liquefied natural gas tank
WO2021209231A1 (en) 2020-04-17 2021-10-21 L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Liquefied gas storage facility
FR3109433A1 (en) 2020-04-17 2021-10-22 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Liquefied gas storage facility.
US20230194160A1 (en) * 2020-04-17 2023-06-22 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Liquefied gas storage facility

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