CN104019628B - Make the method that space division system runs continuously during the supply discontinuity of LNG cold energy - Google Patents

Make the method that space division system runs continuously during the supply discontinuity of LNG cold energy Download PDF

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Publication number
CN104019628B
CN104019628B CN201410203695.3A CN201410203695A CN104019628B CN 104019628 B CN104019628 B CN 104019628B CN 201410203695 A CN201410203695 A CN 201410203695A CN 104019628 B CN104019628 B CN 104019628B
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China
Prior art keywords
nitrogen
heat exchanger
lng
cold energy
air
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CN104019628A (en
Inventor
魏林瑞
张磊
夏永强
江克忠
李亚军
王玉川
王德鹏
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China National Offshore Oil Corp CNOOC
CNOOC Energy Technology and Services Ltd
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China National Offshore Oil Corp CNOOC
CNOOC Energy Technology and Services Ltd
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    • 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04006—Providing pressurised feed air or process streams within or from the air fractionation unit
    • F25J3/04012—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of warm gaseous streams; details of intake or interstage cooling
    • F25J3/04018—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of warm gaseous streams; details of intake or interstage cooling of main feed air
    • 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04006—Providing pressurised feed air or process streams within or from the air fractionation unit
    • F25J3/04048—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of cold gaseous streams, e.g. intermediate or oxygen enriched (waste) streams
    • F25J3/0406—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of cold gaseous streams, e.g. intermediate or oxygen enriched (waste) streams of 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04157—Afterstage cooling and so-called "pre-cooling" of the feed air upstream the air purification unit and main heat exchange line
    • 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04187—Cooling of the purified feed air by recuperative heat-exchange; Heat-exchange with product streams
    • F25J3/04193—Division of the main heat exchange line in consecutive sections having different functions
    • F25J3/04206—Division of the main heat exchange line in consecutive sections having different functions including a so-called "auxiliary vaporiser" for vaporising and producing a gaseous product
    • 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04187—Cooling of the purified feed air by recuperative heat-exchange; Heat-exchange with product streams
    • F25J3/04218—Parallel arrangement of the main heat exchange line in cores having different functions, e.g. in low pressure and high pressure cores
    • 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04187—Cooling of the purified feed air by recuperative heat-exchange; Heat-exchange with product streams
    • F25J3/04218—Parallel arrangement of the main heat exchange line in cores having different functions, e.g. in low pressure and high pressure cores
    • F25J3/04224—Cores associated with a liquefaction or refrigeration 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
    • F25J3/04254—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using the cold stored in external cryogenic fluids
    • F25J3/0426—The cryogenic component does not participate in the fractionation
    • F25J3/04266—The cryogenic component does not participate in the fractionation and being liquefied hydrocarbons
    • F25J3/04272—The cryogenic component does not participate in the fractionation and being liquefied hydrocarbons and comprising means for reducing the risk of pollution of hydrocarbons into the air fractionation
    • 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
    • F25J3/04333—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using quasi-closed loop internal vapor compression refrigeration cycles, e.g. of intermediate or oxygen enriched (waste-)streams
    • F25J3/04351—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using quasi-closed loop internal vapor compression refrigeration cycles, e.g. of intermediate or oxygen enriched (waste-)streams of 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04406—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system
    • F25J3/04412—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system in a classical double column flowsheet, i.e. with thermal coupling by a main reboiler-condenser in the bottom of low pressure respectively top of high pressure column
    • 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04472—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using the cold from cryogenic liquids produced within the air fractionation unit and stored in internal or intermediate storages
    • F25J3/04496—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using the cold from cryogenic liquids produced within the air fractionation unit and stored in internal or intermediate storages for compensating variable air feed or variable product demand by alternating between periods of liquid storage and liquid assist
    • 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04642—Recovering noble gases from air
    • F25J3/04648—Recovering noble gases from air argon
    • F25J3/04654—Producing crude argon in a crude argon column
    • F25J3/04666—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system
    • F25J3/04672—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system having a top condenser
    • F25J3/04678—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system having a top condenser cooled by oxygen enriched liquid from high pressure column bottoms
    • 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04642—Recovering noble gases from air
    • F25J3/04648—Recovering noble gases from air argon
    • F25J3/04721—Producing pure argon, e.g. recovered from a crude argon column
    • F25J3/04727—Producing pure argon, e.g. recovered from a crude argon column using an auxiliary pure argon column for nitrogen rejection
    • 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
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04769—Operation, control and regulation of the process; Instrumentation within the process
    • F25J3/04812—Different modes, i.e. "runs" of operation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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    • 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
    • F25J2210/62—Liquefied natural gas [LNG]; Natural gas liquids [NGL]; Liquefied petroleum gas [LPG]
    • 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
    • F25J2230/04—Compressor cooling arrangement, e.g. inter- or after-stage cooling or condensate removal
    • 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
    • F25J2250/00—Details related to the use of reboiler-condensers
    • F25J2250/30—External or auxiliary boiler-condenser in general, e.g. without a specified fluid or one fluid is not a primary air component or an intermediate fluid
    • F25J2250/40—One fluid being air
    • 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
    • F25J2250/00—Details related to the use of reboiler-condensers
    • F25J2250/30—External or auxiliary boiler-condenser in general, e.g. without a specified fluid or one fluid is not a primary air component or an intermediate fluid
    • F25J2250/42—One fluid being 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
    • F25J2270/00—Refrigeration techniques used
    • F25J2270/90—External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration
    • F25J2270/904—External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration by liquid or gaseous cryogen in an open loop

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Separation By Low-Temperature Treatments (AREA)

Abstract

The invention discloses a kind of method that space division system is run continuously during the supply discontinuity of LNG cold energy, space division system comprises following system: filtration system, compressibility, purification system, cooling system, distillation system, refrigeration compression system and Separate System of Water-jet, wherein refrigeration compression system provides cold energy by LNG, and compression cooling processing is carried out to the nitrogen that distillation system generates, Separate System of Water-jet carries out gas-liquid separation process to the liquid nitrogen that refrigeration compression system generates, generate finished product liquid nitrogen, cooling system comprises two cover heat exchangers, two cover heat exchangers alternately put into operation according to LNG cold energy supply status, wherein a set of is main, its cooling medium comprises the nitrogen that distillation system generates, it is opened for seasonable at LNG cold energy, another set of is auxiliary, and its cooling medium comprises the finished product liquid nitrogen that Separate System of Water-jet generates, and it is opened when the supply discontinuity of LNG cold energy.The present invention can maintain space division system continuous and stable when LNG interrupts runs.

Description

Make the method that space division system runs continuously during the supply discontinuity of LNG cold energy
Technical field
The present invention relates to the method utilizing LNG cold energy to carry out air separation, particularly a kind of method that space division system is run continuously during the supply discontinuity of LNG cold energy.
Background technology
Under normal pressure, LNG is the cryogenic liquid of a kind of-162 DEG C, needed to be gasified before being supplied to downstream user and be heated to more than 0 DEG C, a large amount of cold energy can be released during gasification, 1.0 tons of LNG gasifications approximately can discharge the cold energy of about 230kWh, its economic worth is very high, and be used the energy consumption can saved when a large amount of cryogenic cold energy is produced.Simultaneously almost no waste discharge in cold energy use process, environmental advantage is given prominence to.LNG cold energy is used for the industrial circle of being correlated with, huge energy resource consumption can be reduced and obtain good economic and social benefit, reach the object of energy-saving and environmental protection, so each receiving station is all carrying out research and the through engineering approaches application of LNG cold energy use technology, LNG receiving station also must built supporting cold energy use project as one of condition checked and approved by National Energy Board.
LNG cold energy use form has two classes: 1. directly utilize, and comprises cold energy generation, air separation, cold storage warehouse, liquefied carbon dioxide etc.; 2. indirect utilization, comprises the liquid nitrogen, the liquid oxygen that obtain by air separation and carries out low-temperature grinding, sewage disposal etc.Because the temperature reached needed in air separation unit is also lower than LNG temperature, therefore the utilization of the cold of LNG in air separation unit is technical the most rational best mode, so first the cold energy use project of Ge great receiving station all can be considered to build air separation unit.The air-separating technology flow process of LNG cold is utilized generally to adopt circulating nitrogen gas RecycledNitrogen, be called for short RN reclaims LNG cold as refrigerant, and cold is passed to the precooling that air separation unit is used for air raw material, thermic load between the lower tower condenser of separation and HYDROGEN ISOTOPE EQUILIBRIUM FRACTIONATION BETWEEN system and upper tower reboiler, so utilize the cold of LNG significantly can reduce the compression refrigeration energy consumption of air separation unit, compared with traditional air separation unit, point power consumption of cold energy sky can save more than 50%, cooling water saves more than 70%, the expense of LNG gasification simultaneously also can be reduced.
LNG cold energy use can substitute a large amount of refrigeration energy expenditures.But there is LNG in current LNG cold energy use and gasify that mobility and the cold energy use project demand of load is continuous, the contradiction of stable operation, this technology crux seriously hinders the development of LNG cold energy industry.The amount of vaporization of receiving station LNG can due to the dynamic and frequent variations with wave of downstream user in Different periods and Various Seasonal, during use gas low ebb at night, the amount of vaporization of LNG is little, even stop gasification, cause and utilize the device of LNG cold energy to interrupt cold and can not stable operation, this is the significant challenge that LNG cold energy use faces.Along with the high speed development of China's pipe natural gas, the gas distributing system equilibrium of supply and demand will inevitably require that LNG bears more peak regulation pressure, and the diurnation of LNG receiving station amount of vaporization will be larger, and this contradiction is more outstanding in the future.
Chinese patent CN101943512B has invented a kind of air separating method utilizing cold energy of liquefied natural gas, and the cryogenic cold energy of the LNG being pressurized to authorized pressure organically combines with air gas separation unit by the method, make use of the cold energy of LNG fully.Cryogenic cold energy by LNG is used for producing liquid space division product, to reduce the specific energy consumption of liquid space division product, makes LNG intensification of gasifying in space division system meet the requirements of the defeated temperature of pipe simultaneously.But this patent does not relate to the ruuning situation of air separation unit in defeated load fluctuation situation outside LNG.
60 ~ 80% of receiving station LNG downstream gas load is plant gas, because plant gas has significantly peak load round the clock, in addition the water power in wet season and dry season is uneven, make the gasification load fluctuation of LNG very large, seldom even do not gasify night load, causes the empty sub-item of its LNG cold energy can not meet by cold demand at night.The number of times that 27 middle of the month that domestic certain receiving station LNG air separation unit is gone into operation stop production because LNG supplies continuity interruption reaches 82 times.
Chinese patent CN101839612B has invented a kind of backward flow type air-seperation system based on the cold energy use of LNG satellite station and method.But LNG satellite station scale is less, have larger difference with the receiving station described in this patent, and this patent does not relate to the ruuning situation of the air separation unit when LNG supply is interrupted completely, does not relate to and utilizes external heat exchanger to carry out cooling.The problem that during supply discontinuity of above-mentioned patent all unresolved LNG cold energy, air separation unit stops.
Summary of the invention
The present invention provides a kind of method that space division system is run continuously during the supply discontinuity of LNG cold energy for solving in known technology the technical problem that exists.
The technical scheme that the present invention takes for the technical problem existed in solution known technology is: a kind of method that space division system is run continuously during the supply discontinuity of LNG cold energy, space division system comprises following system: filtration system, compressibility, purification system, cooling system, distillation system, refrigeration compression system and Separate System of Water-jet, described filtration system, described compressibility, described purification system and described cooling system filter raw air successively, compression, purification and cooling processing, described distillation system carries out separating treatment to cooled air and forms nitrogen and liquid oxygen, described refrigeration compression system provides cold energy by LNG, and form liquid nitrogen after compression cooling processing is carried out to the nitrogen that described distillation system is formed, described Separate System of Water-jet carries out gas-liquid separation process to the liquid nitrogen that described refrigeration compression system is formed, form finished product liquid nitrogen, described cooling system comprises two cover heat exchangers, described two cover heat exchangers alternately put into operation according to LNG cold energy supply status, wherein a set of heat exchanger is main heat exchanger, its cooling medium comprises the nitrogen that described distillation system is formed, it is opened for seasonable at LNG cold energy, another set of heat exchanger is supplementary heat exchanger, and its cooling medium comprises the finished product liquid nitrogen that described Separate System of Water-jet is formed, and it is opened when the supply discontinuity of LNG cold energy, simultaneously according to LNG cold energy supply status, adjust the technical parameter of described space division system, make described space division system, increase finished product liquid nitrogen production when LNG cold energy is in liberal supply, and low load operation also stops manufacturing a finished product liquid nitrogen when the supply discontinuity of LNG cold energy, when the supply discontinuity of LNG cold energy, described refrigeration compression system and described Separate System of Water-jet are closed.
Described filtration system comprises air cleaner a1, and described compressibility comprises air compressor machine a3, and described purification system comprises purifier a20, and described cooling system comprises main heat exchanger a12 and the external heat exchanger a22 as supplementary heat exchanger, described distillation system comprises rectifying column, and described refrigeration compression system comprises LNG-nitrogen heat exchanger a6 and nitrogen pressure compression system, and described Separate System of Water-jet comprises the first gas-liquid separator a10 and the second gas-liquid separator a11, described air cleaner a1, described air compressor machine a3 and described purifier a20 connect successively and filter raw air A1, compress and purified treatment, purification of compressed air after process is divided into two-way after described purifier a20 exports, conducting when two-way is different when the supply of LNG cold energy and supply discontinuity, valve of leading up to inputs described main heat exchanger a12, and valve of separately leading up to inputs described external heat exchanger a22, when LNG cold energy is for seasonable, close described external heat exchanger a22, start described main heat exchanger a12 and described LNG-nitrogen heat exchanger a6, described main heat exchanger a12 cools the air from described purifier a20, the air of cooling is exported to described rectifying column after process, the air of described rectifying column to input carries out fractionation, form liquid oxygen and nitrogen, the nitrogen part that tower a15 top is extracted out from described rectifying column discharges cold energy through described main heat exchanger a12, export after described LNG-nitrogen heat exchanger a6 cools again, the nitrogen that described LNG-nitrogen heat exchanger a6 exports inputs described nitrogen pressure compression system and compresses, and liquid nitrogen is become after cooling further, gas-liquid separation is carried out successively again through described first gas-liquid separator a10 and described second gas-liquid separator a11, form nitrogen and finished product liquid nitrogen, wherein finished product liquid nitrogen exports storage tank to, the nitrogen that second gas-liquid separator a11 is separated is as cooling medium input main heat exchanger a12, LNG discharges after cold energy through described LNG-nitrogen heat exchanger a6, be warming up to the defeated temperature of pipe and send into natural gas line, when the supply discontinuity of LNG cold energy, close described main heat exchanger a12, described refrigeration compression system and described Separate System of Water-jet, start described external heat exchanger a22, described finished product liquid nitrogen inputs described external heat exchanger a22 as cooling medium, described external heat exchanger a22 cools the air from described purifier a20, export the air of cooling after process to described rectifying column, described rectifying column is set to low load operation.
Described space division system also comprises LNG-ethylene glycol heat exchanger a5, when LNG cold energy supply is sufficient, LNG is inputed to described LNG-ethylene glycol heat exchanger a5, ethylene glycol solution is utilized to store up cold energy, when LNG cold energy supply is not enough, the glycol water of storage cold energy provides cold energy, for cooling raw air as cooling medium to the intercooler a2 in described air compressor machine and aftercooler a4.
The nitrogen that tower a13 top is extracted out from described rectifying column divides two-way to export, conducting when two-way is different when the supply of LNG cold energy and supply discontinuity, wherein a road is supplying at once to input described main heat exchanger a12 as cooling medium by valve when LNG cold energy, and another road inputs described external heat exchanger a22 as cooling medium by valve when LNG cold energy interrupts, two-way nitrogen is all directly emptying or input described purifier a20 as regeneration gas after heat exchange; The nitrogen that tower a15 top is extracted out from described rectifying column divides three tunnels to export, conducting when first and second Lu Yu tri-tunnel is different when the supply of LNG cold energy and supply discontinuity, when LNG cold energy is for seasonable, the first via inputs described main heat exchanger a12 as cooling medium by valve and carries out heat exchange, input described LNG-nitrogen heat exchanger a6 after heat exchange to cool, described nitrogen pressure compression system is inputted again after cooling, second tunnel inputs described LNG-nitrogen heat exchanger a6 by valve and cools, and inputs described nitrogen pressure compression system after cooling again; When LNG cold energy interrupts, the 3rd tunnel inputs described external heat exchanger a22 as cooling medium by valve, exports external equipment to after heat exchange.
Described refrigeration compression system also comprises liquid nitrogen-nitrogen heat exchanger a9, the nitrogen that described nitrogen pressure compression system exports forms cryogenic high pressure nitrogen after described LNG-nitrogen heat exchanger a6 cools, after described liquid nitrogen-nitrogen heat exchanger a9 cools further, export liquid nitrogen, from the described first gas-liquid separator a10 of liquid nitrogen input that described liquid nitrogen-nitrogen heat exchanger a9 exports, the nitrogen that described first gas-liquid separator a10 is separated and after exporting from described liquid nitrogen-nitrogen heat exchanger a9 reflux liquid nitrogen input described liquid nitrogen-nitrogen heat exchanger a9 respectively as cooling medium, all described LNG-nitrogen heat exchanger a6 is inputed to as cooling medium after heat exchange, described nitrogen pressure compression system is inputted after heat exchange.
Described nitrogen pressure compression system comprises low-temp low-pressure circulating nitrogen gas compressor a7 and cryogenic high pressure circulating nitrogen gas compressor a8, the nitrogen exported from described LNG-nitrogen heat exchanger a6, successively through described low-temp low-pressure circulating nitrogen gas compressor a7, described LNG-nitrogen heat exchanger a6, described cryogenic high pressure circulating nitrogen gas compressor a8 and described LNG-nitrogen heat exchanger a6, exports after two second compression and cooling.
Described space division system also comprises subcooler a16, the liquid nitrogen that described rectifying column condenser/evaporator a14 exports, the liquid nitrogen fraction 16 that under described rectifying column, tower a15 top exports, the oxygen-enriched liquid air exported bottom tower a15 under the lean solution that under described rectifying column, tower a15 bottom exports empty 18 and described rectifying column, described upper tower a13 is inputted respectively after described subcooler a16 heat exchange, the nitrogen that described upper tower a13 top exports and the dirty nitrogen 55 that described upper tower a13 top exports converge after described subcooler a16 heat exchange, two-way is divided to export again, wherein a road is supplying at once to input described main heat exchanger a12 as cooling medium by valve when LNG cold energy, and another road inputs described external heat exchanger a22 as cooling medium by valve when LNG cold energy interrupts.
Described space division system also comprises cyclic nitrogen-air heat exchanger a21, when LNG cold energy is for seasonable, the air exported from described purifier a20 is divided into two-way after described main heat exchanger a12 heat exchange, wherein a road directly inputs described rectifying column, another road is after described cyclic nitrogen-air heat exchanger a21 heat exchange, input described rectifying column, from the isolated liquid nitrogen of described first gas-liquid separator a10, shunt a part of liquid nitrogen and input described cyclic nitrogen-air heat exchanger a21 and air heat-exchange.
Described space division system also comprises crude argon column a17 and pure argon column a18, Argon fraction is extracted out in the middle part of described upper tower a13, input described crude argon column a17 removing oxygen formation process argon wherein, described process argon 44 inputs described pure argon column a18 removing nitrogen wherein and forms seminal fluid argon, sends into storage tank as finished product; Extract oxygen-enriched liquid air out bottom tower a15 under described rectifying column and split into two-way, wherein the described upper tower a13 of a road input, inputs the overhead condenser of described crude argon column a17, inputs described upper tower a13 after heat exchange as cooling medium after another road reducing pressure by regulating flow; Separately extract at top a road nitrogen out from tower a15 described rectifying column, evaporimeter and overhead condenser at the bottom of the tower of described pure argon column a18 successively, inputs described upper tower a13 after heat exchange; The liquid nitrogen that the condenser/evaporator a14 of described rectifying column exports extracts rear shunting out, and the described upper tower a13 of part input, another part inputs the overhead condenser of described pure argon column a18 as cooling medium, inputs described upper tower a13 after heat exchange.
The advantage that the present invention has and good effect are: cooling system arranges two cover heat exchangers, alternately put into operation according to LNG cold energy supply status, wherein a set of heat exchanger is main heat exchanger, and its cooling medium comprises the nitrogen that described distillation system generates, and it is opened for seasonable at LNG cold energy; Another set of heat exchanger is supplementary heat exchanger, and its cooling medium comprises the finished product liquid nitrogen that described Separate System of Water-jet generates, and it is opened when the supply discontinuity of LNG cold energy; Simultaneously according to LNG cold energy supply status, stop described LNG cold energy recovery system equipment operation, and adjust distillation system technical parameter, make when LNG cold energy is in liberal supply, increase liquid nitrogen production; When the supply discontinuity of LNG cold energy, low load operation also stops producing liquid nitrogen, the continuous and stable that can maintain space division system like this runs, solve the outer defeated load of LNG receiving station gasification and cold energy project demands nonsynchronous contradiction in time, a series of losses avoiding space division system frequently to stop bringing; By arranging LNG-ethylene glycol heat exchanger a5, utilize ethylene glycol solution to store up cold energy, when LNG cold energy supply is not enough, the glycol water of storage cold energy provides cold energy, for tentatively cooling raw air, reduces cold energy consumption during LNG cold energy supply deficiency; Subcooler is set, the cold energy discharged in reboiled absorber fractional distillation process.
Accompanying drawing explanation
Fig. 1 is process chart of the present invention.
In figure: a1, air cleaner; A2, air compressor middle-cooling; A3, air compressor machine; A4, air compressor machine end cooler; A5, LNG-ethylene glycol heat exchanger; A6, LNG-nitrogen heat exchanger; A7, low-temp low-pressure circulating nitrogen gas compressor; A8, cryogenic high pressure circulating nitrogen gas compressor; A9, liquid nitrogen-nitrogen heat exchanger; A10, the first gas-liquid separator; A11, the second gas-liquid separator; A12, main heat exchanger; A13, Shang Ta; A14, main condenser evaporimeter; A15, Xia Ta; A16, subcooler; A17, crude argon column; A18, pure argon column; A19, regeneration heater; A20, purifier; A21, cyclic nitrogen-air heat exchanger; A22, external heat exchanger; 1, air A; 3, air B; 4, air F; 11, oxygen-enriched liquid air A; 13, liquid nitrogen A; 14, liquid nitrogen B; 15, liquid nitrogen C; 16, liquid nitrogen fraction; 18, lean solution is empty; 20, nitrogen AA; 21, liquid oxygen; 22, nitrogen BA; 23, nitrogen BB; 25, Argon fraction; 27, nitrogen AB; 28, nitrogen AC; 31, nitrogen C; 33, nitrogen D; 34, liquid nitrogen D; 35 liquid nitrogen DA; 37, liquid nitrogen E; 38, liquid nitrogen F; 39, liquid nitrogen G; 40, nitrogen F; 41, liquid nitrogen H; 42, oxygen-enriched liquid air B; 43, oxygen-enriched liquid air C; 44, process argon; 45, nitrogen AE; 48, seminal fluid argon; 49, liquid nitrogen I; 51, air C; 52, air D; 54, air E; 55, dirty nitrogen; 56, nitrogen BC; 58, nitrogen AD; 60, storage tank finished product liquid nitrogen.
Detailed description of the invention
For summary of the invention of the present invention, Characteristic can be understood further, hereby exemplify following examples, and coordinate accompanying drawing to be described in detail as follows:
Refer to Fig. 1, a kind of method that space division system is run continuously during the supply discontinuity of LNG cold energy, space division system comprises following system: filtration system, compressibility, purification system, cooling system, distillation system, refrigeration compression system and Separate System of Water-jet, described filtration system, described compressibility, described purification system and described cooling system filter raw air successively, compression, purification and cooling processing, described distillation system carries out separating treatment to cooled air and forms nitrogen and liquid oxygen, described refrigeration compression system provides cold energy by LNG, and form liquid nitrogen after compression cooling processing is carried out to the nitrogen that described distillation system is formed, described Separate System of Water-jet carries out gas-liquid separation process to the liquid nitrogen that described refrigeration compression system is formed, form finished product liquid nitrogen, described cooling system comprises two cover heat exchangers, described two cover heat exchangers alternately put into operation according to LNG cold energy supply status, wherein a set of heat exchanger is main heat exchanger, its cooling medium comprises the nitrogen that described distillation system is formed, it is opened for seasonable at LNG cold energy, another set of heat exchanger is supplementary heat exchanger, and its cooling medium comprises the finished product liquid nitrogen that described Separate System of Water-jet is formed, and it is opened when the supply discontinuity of LNG cold energy, simultaneously according to LNG cold energy supply status, adjust the technical parameter of described space division system, make described space division system, increase finished product liquid nitrogen production when LNG cold energy is in liberal supply, and low load operation also stops manufacturing a finished product liquid nitrogen when the supply discontinuity of LNG cold energy, when the supply discontinuity of LNG cold energy, described refrigeration compression system and described Separate System of Water-jet are closed.
Described filtration system can comprise air cleaner a1, and described compressibility can comprise air compressor machine a3, and described purification system can comprise purifier a20, and described cooling system can comprise main heat exchanger a12 and the external heat exchanger a22 as supplementary heat exchanger, described distillation system can comprise rectifying column, and described refrigeration compression system can comprise LNG-nitrogen heat exchanger a6 and nitrogen pressure compression system, and described Separate System of Water-jet can comprise the first gas-liquid separator a10 and the second gas-liquid separator a11, described air cleaner a1, described air compressor machine a3 and described purifier a20 can connect successively and filter raw air A1, compress and purified treatment, purification of compressed air after process can be divided into two-way after described purifier a20 exports, be respectively air B3 and air E54, conducting when two-way is different when the supply of LNG cold energy and supply discontinuity, when LNG cold energy is for seasonable, air B3 conducting, air E54 ends, when the supply discontinuity of LNG cold energy, air B3 ends, air E54 conducting, and a road air B3 inputs described main heat exchanger a12 by valve, and another road air E54 inputs described external heat exchanger a22 by valve, when LNG cold energy is for seasonable, close described external heat exchanger a22, start described main heat exchanger a12 and described LNG-nitrogen heat exchanger a6, described main heat exchanger a12 cools the air from described purifier a20, the air of cooling is exported to described rectifying column after process, the air of described rectifying column to input carries out fractionation, form liquid oxygen and nitrogen, the nitrogen part that tower a15 top is extracted out from described rectifying column discharges cold energy through described main heat exchanger a12, export after described LNG-nitrogen heat exchanger a6 cools again, the nitrogen that described LNG-nitrogen heat exchanger a6 exports inputs described nitrogen pressure compression system and compresses, and liquid nitrogen D34 is become after cooling further, gas-liquid separation is carried out successively again through described first gas-liquid separator a10 and described second gas-liquid separator a11, form nitrogen and finished product liquid nitrogen H41, wherein finished product liquid nitrogen H41 exports storage tank to, the nitrogen F40 that second gas-liquid separator a11 is separated is as cooling medium input main heat exchanger a12, LNG discharges after cold energy through described LNG-nitrogen heat exchanger a6, be warming up to the defeated temperature of pipe and send into natural gas line, when the supply discontinuity of LNG cold energy, close described main heat exchanger a12, described refrigeration compression system and described Separate System of Water-jet, start described external heat exchanger a22, described finished product liquid nitrogen inputs described external heat exchanger a22 as cooling medium, described external heat exchanger a22 cools the air E54 from described purifier a20, export the air of cooling after process to described rectifying column, described rectifying column is set to low load operation.
Described space division system also can comprise LNG-ethylene glycol heat exchanger a5, when LNG cold energy supply is sufficient, LNG can be inputed to described LNG-ethylene glycol heat exchanger a5, ethylene glycol solution is utilized to store up cold energy, when LNG cold energy supply is not enough, the glycol water of storage cold energy can be used as cooling medium provides cold energy, for cooling raw air to the intercooler a2 in described air compressor machine and aftercooler a4.
The nitrogen that tower a13 top is extracted out from described rectifying column can divide two-way to export, conducting when two-way is different when the supply of LNG cold energy and supply discontinuity, wherein a road is inputting described main heat exchanger a12 at once can be used as cooling medium by valve conducting when LNG cold energy, can be directly emptying or input described purifier a20 as regeneration gas after heat exchange, and another road nitrogen BC56 can be used as cooling medium by valve conducting when LNG cold energy interrupts input described external heat exchanger a22, also can be directly emptying or input described purifier a20 as regeneration gas after heat exchange, nitrogen AA20 Ke Fen tri-tunnel that tower a15 top is extracted out from described rectifying column exports, be respectively: first via nitrogen AB27, second road nitrogen AC28 and the 3rd road nitrogen AD58, first, two tunnels and the 3rd tunnel LNG cold energy supply and supply discontinuity time different time conducting, when LNG cold energy is for seasonable, 3rd road nitrogen AD58 ends, first via nitrogen AB27, second road nitrogen AC28 conducting, first via nitrogen AB27 can be used as cooling medium and inputs described main heat exchanger a12 by valve conducting and carry out heat exchange, input described LNG-nitrogen heat exchanger a6 after heat exchange to cool, described nitrogen pressure compression system is inputted again after cooling, second road nitrogen AC28 inputs described LNG-nitrogen heat exchanger a6 by valve conducting and cools, described nitrogen pressure compression system is inputted again after cooling, when LNG cold energy interrupts, the 3rd road nitrogen AD58 conducting, first via nitrogen AB27, the second road nitrogen AC28 end, and the 3rd road nitrogen AD58 can be used as cooling medium and inputs described external heat exchanger a22 by valve conducting, may be output to external equipment after heat exchange.
Described refrigeration compression system also can comprise liquid nitrogen-nitrogen heat exchanger a9, the nitrogen that described nitrogen pressure compression system exports forms cryogenic high pressure nitrogen after described LNG-nitrogen heat exchanger a6 cools, can be passed through after described liquid nitrogen-nitrogen heat exchanger a9 cools further, export liquid nitrogen D34 and liquid nitrogen DA35, the liquid nitrogen D34 exported from described liquid nitrogen-nitrogen heat exchanger a9 inputs described first gas-liquid separator a10, the nitrogen that described first gas-liquid separator a10 is separated and after exporting from described liquid nitrogen-nitrogen heat exchanger a9 the liquid nitrogen DA35 of reflux can be used as cooling medium and input described liquid nitrogen-nitrogen heat exchanger a9 respectively, all can be used as cooling medium after heat exchange and input to described LNG-nitrogen heat exchanger a6, described nitrogen pressure compression system is inputted after heat exchange.
Described nitrogen pressure compression system can comprise low-temp low-pressure circulating nitrogen gas compressor a7 and cryogenic high pressure circulating nitrogen gas compressor a8, the nitrogen exported from described LNG-nitrogen heat exchanger a6 successively through described low-temp low-pressure circulating nitrogen gas compressor a7, described LNG-nitrogen heat exchanger a6, described cryogenic high pressure circulating nitrogen gas compressor a8 and described LNG-nitrogen heat exchanger a6, can export after two second compression and cooling.
Described space division system also can comprise subcooler a16, the liquid nitrogen A13 that described rectifying column condenser/evaporator a14 exports, the liquid nitrogen fraction 16 that under described rectifying column, tower a15 top exports, the oxygen-enriched liquid air A11 exported bottom tower a15 under the lean solution that under described rectifying column, tower a15 bottom exports empty 18 and described rectifying column, described upper tower a13 can be inputted respectively after described subcooler a16 heat exchange, the nitrogen BA22 that described upper tower a13 top exports and the dirty nitrogen 55 that described upper tower a13 top exports can be passed through described subcooler a16 heat exchange, can converge for nitrogen BB23 after heat exchange, nitrogen BB23 can divide two-way to export again, wherein a road is inputting described main heat exchanger a12 at once can be used as cooling medium by valve when LNG cold energy, and another road nitrogen BC56 can be used as cooling medium inputs described external heat exchanger a22 when LNG cold energy interrupts by valve.
Described space division system also can comprise cyclic nitrogen-air heat exchanger a21, when LNG cold energy is for seasonable, air B3 conducting, the air B3 exported from described purifier a20 can be divided into two-way after described main heat exchanger a12 heat exchange, wherein a road can directly input described rectifying column, after cyclic nitrogen described in another Lu Kejing-air heat exchanger a21 heat exchange, input described rectifying column, from the isolated liquid nitrogen E37 of described first gas-liquid separator a10, a part of liquid nitrogen F38 can be shunted and input described cyclic nitrogen-air heat exchanger a21 and air heat-exchange, remainder liquid nitrogen G39 inputs described second gas-liquid separator a11.
Described space division system also can comprise crude argon column a17 and pure argon column a18, Argon fraction 25 is extracted out in the middle part of described upper tower a13, input described crude argon column a17 removing oxygen formation process argon 44 wherein, described process argon 44 inputs described pure argon column a18 removing nitrogen wherein and forms seminal fluid argon 48, sends into storage tank as finished product; Extract oxygen-enriched liquid air A11 under described rectifying column bottom tower a15 out and can split into two-way, be respectively oxygen-enriched liquid air B42 and oxygen-enriched liquid air C43, wherein a road oxygen-enriched liquid air B42 inputs described upper tower a13, input the overhead condenser of described crude argon column a17 after the oxygen-enriched liquid air C43 reducing pressure by regulating flow of another road as cooling medium, after heat exchange, input described upper tower a13; Separately extract at top a road nitrogen AE45 out from tower a15 described rectifying column, evaporimeter and overhead condenser at the bottom of the tower of described pure argon column a18 successively, inputs described upper tower a13 after heat exchange; The liquid nitrogen that the condenser/evaporator a14 of described rectifying column exports extracts rear shunting out, be respectively liquid nitrogen A13 and liquid nitrogen I49, wherein liquid nitrogen I49 part inputs described upper tower a13, liquid nitrogen A13 part inputs the overhead condenser of described pure argon column a18 as cooling medium in addition, inputs described upper tower a13 after heat exchange.
The best processing route of the present invention is as follows:
The scale of air separation unit is as shown in table 1 below:
Air separation unit scale under table 1 normal design operating mode
The original state parameter of feeding air A1 is 0.1MPa, 303K, and molar constituent is: N 2: 0.781; O 2: 0.21; Ar:0.009.LNG is forced into 7.42MPa before feeding pipe network, and its temperature is-145 DEG C.LNG molar constituent is: CH 4: 91.46%; C 2h 6: 4.74%; C 3h 8: 2.59%; N-C 4h 10: 0.57%; I-C 4h 10: 0.54%; N-C 5h 12: 0.01%; N 2: 0.09%.
Because the gasification load fluctuation of LNG is very large, when daytime, LNG cold energy was sufficient, cold energy air separation unit runs under normal design operating mode; Seldom even do not gasify night load time, can not meeting by cold demand of LNG cold energy air separation unit, when the supply of LNG cold energy is greater than setting, as the in liberal supply operating mode process of LNG cold energy, when the supply of LNG cold energy is less than or equal to the limiting value set, operating mode process is interrupted, when the supply of LNG cold energy is greater than the limiting value of setting, as LNG cold energy supply nominal situation as LNG cold energy; Cold energy air separation unit need run under LNG cold energy interrupts operating mode, namely maintains air separation unit by external heat exchanger a22 and the method such as closing device and change device parameter and runs continuously.
One normal design operating mode: the supply of LNG cold energy is normal
Flow is 49200Nm 3the raw air A1 of/hr in filter a1 except after dust and mechanical admixture, enter air compressor machine a3, air compressor machine a3 is Air turbocompressor, air compressor machine a3 is by air compressing extremely about 0.62MPa, the glycol water of storage cold energy provides cold energy as cooling medium to the intercooler a2 in described air compressor machine and aftercooler a4, for cooling raw air, raw air A1 is cooled to 10 DEG C, enters moisture, carbon dioxide, acetylene, propylene, propane, heavy hydrocarbon, N in the purifier a20 absorbed air of purification system 2the impurity such as O, carry out further purified treatment.
The air B3 going out purifier a20 enters main heat exchanger a12 and is cooled to-171 DEG C, main heat exchanger a12 low-temperature receiver is from the nitrogen AB27 at lower tower a15 top and the nitrogen BB23 from upper tower a13 tower top, air B3 is air F4 after described main heat exchanger a12 heat exchange, air F4 is divided into two-way, be respectively air C51 and air D52, one road air C51 directly inputs described rectifying column, and another part air D52 is after cyclic nitrogen-air heat exchanger a21 heat exchange, and deep cooling enters lower tower a15 again after-176 DEG C.
At lower tower a15, its operating pressure is 0.56MPa, has compressed the air initial gross separation of purification cooling.Utilize the concentration difference of uprising gas and down-flowing liquid and component difference to carry out caloic exchange, lower boiling nitrogen is evaporated, and high boiling oxygen is condensed, and the condensation through multistage column plate forms oxygen-enriched liquid air with evaporation in lower tower a15 tower reactor.Form high-purity nitrogen at lower tower a15 tower top, most of the nitrogen steam, through main condenser evaporimeter a14, carries out heat exchange with liquid oxygen bottom upper tower a13, liquid oxygen is evaporated, and nitrogen steam is condensed, the liquid nitrogen of partial condensation is extracted out, and wherein a part of liquid nitrogen I49 returns lower tower a15 after extracting out and makes phegma.A part of liquid nitrogen A13 in addition, its flow is 1000kg/hr, temperature and pressure are respectively-178 DEG C, 0.56MPa, cross in subcooler a16 after being chilled to-186 DEG C and be divided into two-way, be respectively liquid nitrogen B14 and liquid nitrogen C15, wherein a road flow be 587kg/hr liquid nitrogen B14 input on tower a13 as the phegma of upper tower a13; The first throttling of an other road liquid nitrogen C15 is depressurized to 0.15MPa, and then go pure argon column a18 overhead condenser to provide cold, its outlet temperature is-192 DEG C, the upper tower a13 of input afterwards.
The oxygen-enriched liquid air A11 of 30337kg/hr is extracted out bottom lower tower a15, its temperature is-173 DEG C, cross in subcooler a16 after being chilled to-177 DEG C and split into oxygen-enriched liquid air B42 and oxygen-enriched liquid air C43, wherein flow be 13100kg/hr oxygen-enriched liquid air B42 input on tower a13 as phegma, the first throttling of the oxygen-enriched liquid air C43 of a part of 0.58MPa is depressurized to 0.15MPa in addition, then the overhead condenser inputting crude argon column a17 provides cold, and its outlet temperature is-185 DEG C, the upper tower a13 of input afterwards.9731kg/hr is extracted on lower tower a15 top out, 5435kg/hr is taken out in the liquid nitrogen fraction 16 of-177 DEG C, lower tower a15 bottom, the lean solution sky 18 of-175 DEG C, cross in subcooler a16 respectively and be chilled to-190 DEG C ,-178 DEG C, the upper tower a13 of input afterwards, the reflux ratio of tower a13 in increase, the operating pressure of upper tower a13 is 0.13MPa.
Two-way nitrogen is extracted out from lower tower a15 top, one road 525kg/hr, the nitrogen AE45 of-177 DEG C, evaporimeter at the bottom of the tower of input pure argon column a18, an other road 33620kg/hr, the nitrogen AA20 of-177 DEG C, split into three tunnels, be respectively nitrogen AB27, nitrogen AC28 and nitrogen AD58, wherein nitrogen AB27, nitrogen AC28 is in LNG cold energy supply conducting, nitrogen AD58 ends for seasonable at LNG cold energy, wherein flow is that the nitrogen AB27 of 24122kg/hr is after main heat exchanger a12 is warming up to 14 DEG C, input LNG-nitrogen heat exchanger a6, nitrogen AC28 is through liquid nitrogen-nitrogen heat exchanger a9 in addition, be warming up to-144 DEG C of laggard LNG-nitrogen heat exchanger a6, 12860kg/hr, the liquid oxygen 21 of-180 DEG C is extracted out from main condenser evaporimeter a14, storage tank is sent into as finished product cooling box.
Extract temperature out from upper tower a13 top and be-192 DEG C, pressure is 0.13MPa, flow is the nitrogen BA22 of 14523kg/hr, extract temperature out from upper tower a13 top and be-192 DEG C, pressure is 0.13MPa, flow is the dirty nitrogen 55 of 8905kg/hr, input subcooler a16 respectively, with liquid nitrogen A13 in subcooler a16, liquid nitrogen fraction 16, lean solution empty 18 and oxygen-enriched liquid air A11 carry out heat exchange, the nitrogen BB23 of-175 DEG C is merged into as after exchange, nitrogen BB23 is divided into two-way, wherein a road is nitrogen BC56, at LNG cold energy for seasonable cut-off, the conducting when the supply discontinuity of LNG cold energy also inputs external heat exchanger a22, an other road is ended when the supply discontinuity of LNG cold energy, and supply seasonable conducting and input main heat exchanger a12 to be warming up to 14 DEG C of outputs at LNG cold energy, a nitrogen part for output goes purifier a20 as regeneration gas, and remainder is emptying.
The Argon fraction 25 of 14951kg/hr ,-180 DEG C and 0.14MPa is extracted out and is sent into crude argon column a17 in the middle part of upper tower a13, and the operating pressure of crude argon column a17 is 0.13MPa, removes oxygen wherein, obtain process argon 44 in crude argon column a17.410kg/hr, the process argon 44 of-183 DEG C send into pure argon column a18, and the operating pressure of pure argon column a18 is 0.12MPa, removes nitrogen wherein in pure argon column, obtain 410kg/hr, the seminal fluid argon 48 of-183 DEG C, send into storage tank as finished product in the bottom of pure argon column a18.
Flow is that the LNG of-145 DEG C of 58197kg/hr gasifies, heats up in LNG-nitrogen heat exchanger a6, a part is warming up to environment temperature, 51002kg/hr, the LNG of-70 DEG C extract out from the middle part of LNG-nitrogen heat exchanger a6 in addition, input cooling LNG-ethylene glycol heat exchanger a5, two parts converge, send into natural gas line afterwards.Flow is that the nitrogen AB27 of 24122kg/hr is warming up to 14 DEG C of input LNG-nitrogen heat exchanger a6 through main heat exchanger a12, nitrogen AC28 is through liquid nitrogen-nitrogen heat exchanger a9, be warming up to-144 DEG C of laggard LNG-nitrogen heat exchanger a6, both all converges output nitrogen C31 in LNG-nitrogen heat exchanger a6 after heat exchange, be compressed to 2.3MPa by low-temp low-pressure circulating nitrogen gas compressor a7, and then be compressed to 7MPa by cryogenic high pressure circulating nitrogen gas compressor a8 and become nitrogen D33.Nitrogen D33 inputs liquid nitrogen DA35 heat exchange that liquid nitrogen-nitrogen heat exchanger a9 and throttling backflow, liquefaction, liquid nitrogen D34 throttling in the first gas-liquid separator a10 is separated, liquid nitrogen E37 bottom a10 splits into two-way, be respectively liquid nitrogen F38 and liquid nitrogen G39, wherein 18372kg/hr, the liquid nitrogen F38 of-192 DEG C input cyclic nitrogen-air heat exchanger a21 and air heat-exchange, and cold is passed to fractionating system; Another liquid nitrogen G39 sends into the second gas-liquid separator a11 and carries out gas-liquid separation, 12677kg/hr ,-192 DEG C liquid nitrogen H41 as liquid nitrogen finished product send into storage tank, second gas-liquid separator a11 is separated the nitrogen F40 generated, input main heat exchanger a12, input external equipment after heat exchange, the first gas-liquid separator a10 and the second gas-liquid separator a11 design pressure are respectively 0.58MPa and 0.15MPa.
Two LNG cold energy supply discontinuity operating modes
Flow is 36900Nm 3raw air A1 in filter a1 except after dust and mechanical admixture, enter in air compressor machine a3, by air compressing to about 0.62MPa, the glycol water of storage cold energy provides cold energy as cooling medium to the intercooler a2 in described air compressor machine and aftercooler a4, for cooling raw air, raw air A1 is cooled to 10 DEG C, enters moisture, carbon dioxide, acetylene, propylene, propane, heavy hydrocarbon, N in the purifier a20 absorbed air of purification system 2the impurity such as O, carry out further purified treatment.
LNG-nitrogen heat exchanger a6 stops using, and stops circulating nitrogen gas compression, condensation process, stops producing liquid nitrogen.The air E54 going out purifier a20 enters external heat exchanger a22 and is cooled to-174 DEG C, the low-temperature receiver of external heat exchanger a22 is except upper tower a13 nitrogen overhead BC56 and lower tower a15 top nitrogen AD58, also need 10000kg/hr, the storage tank finished product liquid nitrogen 60 of-192 DEG C provides cold energy, storage tank liquid nitrogen is from finished product liquid nitrogen H41.
At lower tower a15, its operating pressure is 0.56MPa, the air initial gross separation cooled.Utilize the concentration difference of uprising gas and down-flowing liquid and component difference to carry out caloic exchange, lower boiling nitrogen is evaporated, and high boiling oxygen is condensed, and the condensation through multistage column plate forms oxygen-enriched liquid air with evaporation in lower tower a15 tower reactor.High-purity nitrogen is formed at lower tower a15 tower top, most of the nitrogen steam is through main condenser evaporimeter a14, and carry out heat exchange with liquid oxygen bottom upper tower a13, liquid oxygen is evaporated, and nitrogen steam is condensed and forms liquid nitrogen and extract out, extract liquid nitrogen I49 part out and return lower tower a15 and make phegma.A part of liquid nitrogen A13 in addition, its flow is 875kg/hr, temperature and pressure are respectively-178 DEG C, 0.56MPa, crossing in subcooler a16 after being chilled to-186 DEG C is divided into two-way to be respectively liquid nitrogen B14 and liquid nitrogen C15, a road flow be 462kg/hr liquid nitrogen B14 feeding on tower a13 as the phegma of upper tower a13; The first throttling of an other road liquid nitrogen C15 is depressurized to 0.15MPa, and then go the overhead condenser of pure argon column a18 to provide cold, its outlet temperature is-192 DEG C, returns tower a13 afterwards.
The oxygen-enriched liquid air A11 of 29140kg/hr is extracted out bottom lower tower a15, its temperature is-174 DEG C, cross in subcooler a16 and be chilled to-179 DEG C, two-way is divided into be oxygen-enriched liquid air B42 and oxygen-enriched liquid air C43, wherein flow be 12095kg/hr oxygen-enriched liquid air B42 input on tower a13 as phegma, the first throttling of the oxygen-enriched liquid air C43 of another road 0.58MPa is depressurized to 0.15MPa, and the overhead condenser then inputting crude argon column a17 provides cold for it, its outlet temperature is-187 DEG C, the upper tower a13 of input afterwards.10346kg/hr, the liquid nitrogen fraction 16 of-177 DEG C, the 5347kg/hr of lower tower a15 bottom extraction, the lean solution sky 18 of-175 DEG C that lower tower a15 top is extracted out, cross respectively through subcooler a16 and be chilled to-190 DEG C ,-178 DEG C, the upper tower a13 of input afterwards, the reflux ratio of tower a13 in increase, the operating pressure of upper tower a13 is 0.13MPa.
Two-way nitrogen is extracted out from lower tower a15 top, be respectively nitrogen AA20 and nitrogen AE45, a wherein road 375kg/hr, the nitrogen AE45 of-177 DEG C, evaporimeter at the bottom of the tower of input pure argon column a18, 625kg/hr in addition, the nitrogen AA20 of-177 DEG C, split into three tunnels, be respectively nitrogen AB27, nitrogen AC28 and nitrogen AD58, wherein nitrogen AB27, nitrogen AC28 ends when the supply discontinuity of LNG cold energy, nitrogen AD58 conducting when the supply discontinuity of LNG cold energy, 625kg/hr, the nitrogen AD58 of-177 DEG C inputs cooling-air E54 in external heat exchanger a22, be warming up to 14 DEG C and export external equipment to.
9856kg/hr, the liquid oxygen 21 of-180 DEG C are extracted out from main condenser evaporimeter a14, send into storage tank as finished product.
The nitrogen BA22 that flow is 35780kg/hr, temperature is-193 DEG C, pressure is 0.13MPa, extract out from upper tower a13 top and carry out heat exchange with liquid nitrogen A13, liquid nitrogen fraction 16, lean solution empty 18 and oxygen-enriched liquid air A11 in subcooler a16, be warming up to-175 DEG C, then enter external heat exchanger a22 and be warming up to 14 DEG C, a part goes purifier a20 as regeneration gas, remaining emptying.
The Argon fraction 25 of 13423kg/hr ,-180 DEG C and 0.14MPa is extracted out and is sent into crude argon column a17 in the middle part of upper tower a13, removes oxygen wherein, obtain process argon 44 in crude argon column a17.232kg/hr, the process argon 44 of-183 DEG C are sent into pure argon column a18 and are removed nitrogen wherein, obtain 226kg/hr, the seminal fluid argon 48 of-183 DEG C, send into storage tank as finished product bottom pure argon column a18.
Because LNG cold energy interrupts, LNG cold will do not had to cool ethylene glycol solution, so it is cold to utilize daytime ethylene glycol solution to store up when LNG cold energy is abundant, when cold energy interrupts, be directly used in the raw air after cooled compressed.
Three recover nominal situation: the supply of LNG cold energy recovers normal
Recover the starting stage in LNG supply, its flow process is substantially identical with normal design operating mode, and difference is the flow now increasing lower column overhead nitrogen AA20, reaches 38370kg/hr, needs the amount of vaporization increasing LNG simultaneously.Flow is that the LNG of-145 DEG C of 60595kg/hr gasifies, heats up in LNG-nitrogen heat exchanger a6, a part is warming up to environment temperature, in addition 51002kg/hr ,-70 DEG C LNG from middle part extract out export LNG-ethylene glycol heat exchanger a5 to, go to cool glycol water, two parts converge, send afterwards.Increase liquid nitrogen production by this operation, supplement the liquid nitrogen consumed when cold energy interrupts night.After liquid nitrogen liquid oxygen output reaches balance, device can be returned to normal design operating mode and run.
Each Work condition analogue result is as shown in table 2 below:
Table 2 flowsheeting result
As can be seen from the table:
Under a normal design operating mode, liquid oxygen output is 12.86t/h, and liquid nitrogen production is 12.68t/h, and liquid argon yield is 0.41t/h.LNG-nitrogen heat exchanger a6 needs LNG to provide 5616kW cold, and glycol-cooled needs 5912kW cold.In order to meet this two parts cold, need the LNG gasification cooling of 58t/h.Meanwhile, circulating nitrogen gas compresses the merit consumed is 2610kW.
B, under LNG cold energy supply discontinuity operating mode, utilizes liquid nitrogen cooling.The load of air separation unit being reduced to 75% of normal design operating mode, simultaneously by changing technique, making not production fluid nitrogen, thus reduce the cold load needed for night.If the LNG cold energy supply discontinuity duration at night is 6 hours, then according to analog result: night, liquid oxygen output was 9.86 × 6=59.16t, liquid nitrogen production is 0t, and liquid argon yield is 0.23 × 6=1.38t.External heat exchanger a22 needs liquid nitrogen to provide 1152kW cold, namely needs 10t/h liquid nitrogen.Calculated by 6 hours nights, need during the supply discontinuity of LNG cold energy night to consume 60t liquid nitrogen.Although night consumes liquid nitrogen, such operation maintains the continuous operation of cold energy air separation unit, and stops producing the compression power consumption that liquid nitrogen can save major part.
Glycol-cooled needs 4125kW cold, and this part cold is comparatively large, so LNG cold energy in liberal supply stage by day, is cooled to by ethylene glycol solution temperature required, carries out Chu Leng with LNG.When the supply discontinuity of LNG cold energy, carry out the raw air after cooled compressed with the cold energy of low-temperature glycol solution storage.
Under c recovers nominal situation, by changing process reform product slates situation, increase liquid nitrogen production, thus supplement the liquid nitrogen consumed when night, LNG cold energy interrupted.If the LNG cold energy in liberal supply duration is 18 hours, then according to analog result: daytime, liquid oxygen output was 9.59 × 18=172.62t/h, liquid nitrogen production is 16.60 × 18=298.80t/h, and liquid argon yield is 0.26 × 18=4.68t/h.LNG is needed to provide 6087kW cold in LNG-nitrogen heat exchanger a6; And glycol-cooled needs 5912kW cold.In order to meet this two parts cold, need the LNG gasification cooling of 61t/h.Meanwhile, circulating nitrogen gas compresses the merit consumed is 2954kW.
Device, after liquid nitrogen liquid oxygen output reaches balance, can be returned to normal design operating mode and run by d, utilizes LNG gasification cooling.
In a word, utilize liquid nitrogen cooling by external heat exchanger, simultaneously change of load and product slates situation, the outer defeated load of LNG receiving station gasification and cold energy project demands nonsynchronous contradiction in time can be solved, ensure that the continuous and stable of empty sub-item runs.
Although be described the preferred embodiments of the present invention by reference to the accompanying drawings above; but the present invention is not limited to above-mentioned detailed description of the invention; above-mentioned detailed description of the invention is only schematic; be not restrictive; those of ordinary skill in the art is under enlightenment of the present invention; do not departing under the ambit that present inventive concept and claim protect, can also make a lot of form, these all belong within protection scope of the present invention.

Claims (9)

1. the method that space division system is run continuously during the supply discontinuity of LNG cold energy, it is characterized in that, space division system comprises following system: filtration system, compressibility, purification system, cooling system, distillation system, refrigeration compression system and Separate System of Water-jet, described filtration system, described compressibility, described purification system and described cooling system filter raw air successively, compression, purification and cooling processing, described distillation system carries out separating treatment to cooled air and forms nitrogen and liquid oxygen, described refrigeration compression system provides cold energy by LNG, and form liquid nitrogen after compression cooling processing is carried out to the nitrogen that described distillation system is formed, described Separate System of Water-jet carries out gas-liquid separation process to the liquid nitrogen that described refrigeration compression system is formed, form finished product liquid nitrogen, described cooling system comprises two cover heat exchangers, described two cover heat exchangers alternately put into operation according to LNG cold energy supply status, wherein a set of heat exchanger is main heat exchanger, its cooling medium comprises the nitrogen that described distillation system is formed, it is opened for seasonable at LNG cold energy, another set of heat exchanger is supplementary heat exchanger, and its cooling medium comprises the finished product liquid nitrogen that described Separate System of Water-jet is formed, and it is opened when the supply discontinuity of LNG cold energy, simultaneously according to LNG cold energy supply status, adjust the technical parameter of described space division system, make described space division system, increase finished product liquid nitrogen production when LNG cold energy is in liberal supply, and low load operation also stops manufacturing a finished product liquid nitrogen when the supply discontinuity of LNG cold energy, when the supply discontinuity of LNG cold energy, described refrigeration compression system and described Separate System of Water-jet are closed.
2. the method that space division system is run continuously during the supply discontinuity of LNG cold energy according to claim 1, it is characterized in that, described filtration system comprises air cleaner (a1), described compressibility comprises air compressor machine (a3), described purification system comprises purifier (a20), and described cooling system comprises main heat exchanger (a12) and the external heat exchanger (a22) as supplementary heat exchanger, described distillation system comprises rectifying column, described refrigeration compression system comprises LNG-nitrogen heat exchanger (a6) and nitrogen pressure compression system, and described Separate System of Water-jet comprises the first gas-liquid separator (a10) and the second gas-liquid separator (a11), described air cleaner (a1), described air compressor machine (a3) and described purifier (a20) connect successively and filter raw air A (1), compress and purified treatment, purification of compressed air after process is divided into two-way after described purifier (a20) exports, conducting when two-way is different when the supply of LNG cold energy and supply discontinuity, valve of leading up to inputs described main heat exchanger (a12), and valve of separately leading up to inputs described external heat exchanger (a22), when LNG cold energy is for seasonable, close described external heat exchanger (a22), start described main heat exchanger (a12) and described LNG-nitrogen heat exchanger (a6), described main heat exchanger (a12) cools the air from described purifier (a20), the air of cooling is exported to described rectifying column after process, the air of described rectifying column to input carries out fractionation, form liquid oxygen and nitrogen, the nitrogen part that tower (a15) top is extracted out from described rectifying column discharges cold energy through described main heat exchanger (a12), export after described LNG-nitrogen heat exchanger (a6) cooling again, the nitrogen that described LNG-nitrogen heat exchanger (a6) exports inputs described nitrogen pressure compression system and compresses, and liquid nitrogen is become after cooling further, gas-liquid separation is carried out successively again through described first gas-liquid separator (a10) and described second gas-liquid separator (a11), form nitrogen and finished product liquid nitrogen, wherein finished product liquid nitrogen exports storage tank to, the nitrogen that second gas-liquid separator (a11) is separated inputs main heat exchanger (a12) as cooling medium, LNG is after described LNG-nitrogen heat exchanger (a6) discharges cold energy, be warming up to the defeated temperature of pipe and send into natural gas line, when the supply discontinuity of LNG cold energy, close described main heat exchanger (a12), described refrigeration compression system and described Separate System of Water-jet, start described external heat exchanger (a22), described finished product liquid nitrogen inputs described external heat exchanger (a22) as cooling medium, described external heat exchanger (a22) cools the air from described purifier (a20), export the air of cooling after process to described rectifying column, described rectifying column is set to low load operation.
3. the method that space division system is run continuously during the supply discontinuity of LNG cold energy according to claim 2, it is characterized in that, described space division system also comprises LNG-ethylene glycol heat exchanger (a5), when LNG cold energy supply is sufficient, LNG is inputed to described LNG-ethylene glycol heat exchanger (a5), ethylene glycol solution is utilized to store up cold energy, when LNG cold energy supply is not enough, the glycol water of storage cold energy provides cold energy, for cooling raw air as cooling medium to the intercooler (a2) in described air compressor machine and aftercooler (a4).
4. the method that space division system is run continuously during the supply discontinuity of LNG cold energy according to claim 2, it is characterized in that, the nitrogen that tower (a13) top is extracted out from described rectifying column divides two-way to export, conducting when two-way is different when the supply of LNG cold energy and supply discontinuity, wherein a road is supplying at once to input described main heat exchanger (a12) as cooling medium by valve when LNG cold energy, and another road inputs described external heat exchanger (a22) as cooling medium by valve when LNG cold energy interrupts, two-way nitrogen is all directly emptying or input described purifier (a20) as regeneration gas after heat exchange, the nitrogen that tower (a15) top is extracted out from described rectifying column divides three tunnels to export, conducting when first and second Lu Yu tri-tunnel is different when the supply of LNG cold energy and supply discontinuity, when LNG cold energy is for seasonable, the first via inputs described main heat exchanger (a12) as cooling medium by valve and carries out heat exchange, input described LNG-nitrogen heat exchanger (a6) after heat exchange to cool, described nitrogen pressure compression system is inputted again after cooling, second tunnel inputs described LNG-nitrogen heat exchanger (a6) by valve and cools, and inputs described nitrogen pressure compression system after cooling again, when LNG cold energy interrupts, the 3rd tunnel inputs described external heat exchanger (a22) as cooling medium by valve, exports external equipment to after heat exchange.
5. the method that space division system is run continuously during the supply discontinuity of LNG cold energy according to claim 2, it is characterized in that, described refrigeration compression system also comprises liquid nitrogen-nitrogen heat exchanger (a9), the nitrogen that described nitrogen pressure compression system exports forms cryogenic high pressure nitrogen after described LNG-nitrogen heat exchanger (a6) cooling, after described liquid nitrogen-nitrogen heat exchanger (a9) further cooling, export liquid nitrogen, from described first gas-liquid separator (a10) of liquid nitrogen input that described liquid nitrogen-nitrogen heat exchanger (a9) exports, the nitrogen that described first gas-liquid separator (a10) is separated and after exporting from described liquid nitrogen-nitrogen heat exchanger (a9) liquid nitrogen of reflux input described liquid nitrogen-nitrogen heat exchanger (a9) respectively as cooling medium, all described LNG-nitrogen heat exchanger (a6) is inputed to as cooling medium after heat exchange, described nitrogen pressure compression system is inputted after heat exchange.
6. the method that space division system is run continuously during the supply discontinuity of LNG cold energy according to claim 2, it is characterized in that, described nitrogen pressure compression system comprises low-temp low-pressure circulating nitrogen gas compressor (a7) and cryogenic high pressure circulating nitrogen gas compressor (a8), the nitrogen exported from described LNG-nitrogen heat exchanger (a6) is successively through described low-temp low-pressure circulating nitrogen gas compressor (a7), described LNG-nitrogen heat exchanger (a6), described cryogenic high pressure circulating nitrogen gas compressor (a8) and described LNG-nitrogen heat exchanger (a6), export after two second compression and cooling.
7. the method that space division system is run continuously during the supply discontinuity of LNG cold energy according to claim 2, it is characterized in that, described space division system also comprises subcooler (a16), the liquid nitrogen that described rectifying column condenser/evaporator (a14) exports, the liquid nitrogen fraction that under described rectifying column, tower (a15) top exports, the oxygen-enriched liquid air that under the empty and described rectifying column of the lean solution that under described rectifying column, tower (a15) bottom exports, tower (a15) bottom exports, the upper tower (a13) of described rectifying column is inputted respectively after described subcooler (a16) heat exchange, the dirty nitrogen that the nitrogen of upper tower (a13) top output of described rectifying column and upper tower (a13) top of described rectifying column export converges after described subcooler (a16) heat exchange, two-way is divided to export again, wherein a road is supplying at once to input described main heat exchanger (a12) as cooling medium by valve when LNG cold energy, and another road inputs described external heat exchanger (a22) as cooling medium by valve when LNG cold energy interrupts.
8. the method that space division system is run continuously during the supply discontinuity of LNG cold energy according to claim 2, it is characterized in that, described space division system also comprises cyclic nitrogen-air heat exchanger (a21), when LNG cold energy is for seasonable, the air exported from described purifier (a20) is divided into two-way after described main heat exchanger (a12) heat exchange, wherein a road directly inputs described rectifying column, another road is after the heat exchange of described cyclic nitrogen-air heat exchanger (a21), input described rectifying column, from the isolated liquid nitrogen of described first gas-liquid separator (a10), shunt a part of liquid nitrogen and input described cyclic nitrogen-air heat exchanger (a21) and air heat-exchange.
9. the method that space division system is run continuously during the supply discontinuity of LNG cold energy according to claim 2, it is characterized in that, described space division system also comprises crude argon column (a17) and pure argon column (a18), Argon fraction is extracted out from upper tower (a13) middle part of described rectifying column, input described crude argon column (a17) removing oxygen formation process argon wherein, described process argon inputs described pure argon column (a18) removing nitrogen wherein and forms seminal fluid argon, sends into storage tank as finished product; Under described rectifying column, tower (a15) bottom is extracted oxygen-enriched liquid air out and is split into two-way, wherein a road inputs the upper tower (a13) of described rectifying column, input the overhead condenser of described crude argon column (a17) after another road reducing pressure by regulating flow as cooling medium, after heat exchange, input the upper tower (a13) of described rectifying column; Separately extract a road nitrogen out from tower (a15) top described rectifying column, evaporimeter and overhead condenser at the bottom of the tower of described pure argon column (a18) successively, inputs the upper tower (a13) of described rectifying column after heat exchange; The liquid nitrogen that the condenser/evaporator (a14) of described rectifying column exports extracts rear shunting out, the upper tower (a13) of the described rectifying column of part input, another part inputs the overhead condenser of described pure argon column (a18) as cooling medium, inputs the upper tower (a13) of described rectifying column after heat exchange.
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