CN104019628A - Method for enabling air separation system to continuously operate in LNG cold energy supply interruption period - Google Patents

Method for enabling air separation system to continuously operate in LNG cold energy supply interruption period Download PDF

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Publication number
CN104019628A
CN104019628A CN201410203695.3A CN201410203695A CN104019628A CN 104019628 A CN104019628 A CN 104019628A CN 201410203695 A CN201410203695 A CN 201410203695A CN 104019628 A CN104019628 A CN 104019628A
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China
Prior art keywords
nitrogen
heat exchanger
lng
cold energy
air
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Granted
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CN201410203695.3A
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Chinese (zh)
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CN104019628B (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
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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
    • 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
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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
    • 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
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    • 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]
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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
    • 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
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    • 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
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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
    • 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 method for enabling an air separation system to continuously operate in an LNG cold energy supply interruption period. The air separation system comprises a filtration system, a compression system, a purification system, a cooling system, a rectification system, a refrigeration and compression system and a gas-liquid separation system. The refrigeration and compression system is provided with cold energy through LNG and compresses and cools nitrogen gas generated by the rectification system; the gas-liquid separation system performs gas-liquid separation treatment on liquid nitrogen generated by the refrigeration and compression system to generate finished product liquid nitrogen; the cooling system comprises two heat exchangers which are alternately put into operation according to the supply state of the LNG cold energy, one heat exchanger is taken as the primary, cooling media of the primary heat exchanger comprise the nitrogen gas generated by the rectification system, and the primary heat exchanger is turned on when the LNG cold energy is supplied; the other heat exchanger is taken as the auxiliary, cooling media of the auxiliary heat exchanger comprise the finished product liquid nitrogen generated by the gas-liquid separation system, and the auxiliary heat exchanger is turned on when LNG cold energy supply is interrupted. The method can keep continuous and stable operation of the air separation system when the LNG supply is interrupted.

Description

The method that space division system is moved continuously during the supply discontinuity of LNG cold energy
Technical field
The present invention relates to utilize LNG cold energy to carry out the method for air separation, particularly a kind of method that space division system is moved continuously during the supply discontinuity of LNG cold energy.
Background technology
Under normal pressure, LNG is the cryogenic liquid of a kind of-162 ℃, before being supplied to downstream user, need its gasification and be heated to more than 0 ℃, during gasification, can emit a large amount of cold energy, 1.0 tons of LNG gasifications approximately can discharge the cold energy of about 230kWh, its economic worth is very high, is used and can saves the energy consumption of a large amount of cryogenic cold energy while producing.No waste discharge almost in cold energy use process simultaneously, environmental advantage is outstanding.LNG cold energy is used for to relevant industrial circle, can reduce huge energy resource consumption 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, Ye Jiang LNG receiving station of National Energy Board must build supporting cold energy use project as one of condition of checking and approving.
LNG cold energy use form has two classes: 1. directly utilize, comprise cold energy generation, air separation, cold storage warehouse, liquefied carbon dioxide etc.; 2. indirect utilization, comprises that the liquid nitrogen, the liquid oxygen that by air separation, obtain carry out low-temperature grinding, sewage disposal etc.Because the required temperature reaching in air separation unit is also lower than LNG temperature, so the utilization of the cold of LNG in air separation unit be the most rational technical best mode, so first the cold energy use project of Ge great receiving station all can consider to build air separation unit.Utilize the air-separating technology flow process of LNG cold generally to adopt circulating nitrogen gas Recycled Nitrogen, be called for short RN and as refrigerant, reclaim the cold of LNG, and cold is passed to air separation unit for the precooling of air raw material, the lower tower condenser of separation and HYDROGEN ISOTOPE EQUILIBRIUM FRACTIONATION BETWEEN system and the thermic load between upper tower reboiler, so utilize the cold of LNG can significantly reduce the compression refrigeration energy consumption of air separation unit, compare with traditional air separation unit, the empty minute power consumption of cold energy can be saved more than 50%, cooling water is saved 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.Yet the mobility that exists at present LNG gasification load in LNG cold energy use is continuous with cold energy use project demand, the contradiction of stable operation, and this technology crux has seriously hindered the development of LNG cold energy industry.The amount of vaporization of the LNG of receiving station different periods and Various Seasonal can due to downstream user by the moving and frequent variations of wave, night LNG during use gas low ebb amount of vaporization seldom, even stop gasification, cause and utilize the device of LNG cold energy to interrupt cold and can not stable operation, this be 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 LNG to bear 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 that utilizes cold energy of liquefied natural gas, and the method organically combines the cryogenic cold energy and the air gas separation unit that are pressurized to the LNG of authorized pressure, has utilized fully the cold energy of LNG.The cryogenic cold energy that is about to LNG is used for producing liquid space division product, to reduce the specific energy consumption of liquid space division product, makes LNG gasify in space division system to heat up to meet the requirements of to manage defeated temperature simultaneously.But this patent does not relate to the ruuning situation of air separation unit in the outer defeated load fluctuation situation of LNG.
60～80% of the LNG of receiving station downstream use 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 gasify and load night, causes the use cold demand of the empty sub-item of its LNG cold energy at night not meet.The number of times that interrupt stopping production 27 middle of the month that domestic certain LNG of receiving station air separation unit is gone into operation because of LNG supply continuity reaches 82 times.
Chinese patent CN101839612B has invented a kind of backward flow type air-seperation system and method based on the cold energy use of LNG satellite station.But LNG satellite station scale is less, have larger difference with the receiving station described in this patent, and this patent do not relate to the ruuning situation of air separation unit when LNG supply is interrupted completely, do not relate to and utilize external heat exchanger to carry out cooling.The above-mentioned patent problem that all air separation unit stops during unresolved LNG cold energy supply discontinuity.
Summary of the invention
The present invention provides a kind of method that space division system is moved continuously during the supply discontinuity of LNG cold energy for solving the technical problem existing in known technology.
The technical scheme that the present invention takes for the technical problem existing in solution known technology is: a kind of method that space division system is moved 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, purify 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 after being compressed to cooling processing, the nitrogen of described distillation system formation forms liquid nitrogen, the liquid nitrogen that described Separate System of Water-jet forms described refrigeration compression system carries out gas-liquid separation processing, 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 forms, 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 forms, and it opens 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, when LNG cold energy is in liberal supply, increase finished product liquid nitrogen production, and when the supply discontinuity of LNG cold energy low load operation the liquid nitrogen that stops manufacturing a finished product, 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 as the external heat exchanger a22 of 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 to raw air A1 filter, compression and purified treatment, purification of compressed air after processing is divided into two-way from described purifier a20 output, conducting when two-way is different when the supply of LNG cold energy and supply discontinuity, the valve of leading up to is inputted described main heat exchanger a12, and the valve of separately leading up to is inputted 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 carries out cooling to the air from described purifier a20, after processing, export cooling air to described rectifying column, described rectifying column carries out fractionation to the air of input, form liquid oxygen and nitrogen, the nitrogen part that extract out at tower a15 top from described rectifying column discharges cold energy through described main heat exchanger a12, output after described LNG-nitrogen heat exchanger a6 is cooling again, the nitrogen of described LNG-nitrogen heat exchanger a6 output is inputted described nitrogen pressure compression system and is compressed, and become liquid nitrogen after further cooling, through described the first gas-liquid separator a10 and described the second gas-liquid separator a11, carry out gas-liquid separation successively again, form nitrogen and finished product liquid nitrogen, wherein finished product liquid nitrogen exports storage tank to, the nitrogen of the second gas-liquid separator a11 separation is as cooling medium input main heat exchanger a12, 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 is inputted described external heat exchanger a22 as cooling medium, described external heat exchanger a22 carries out cooling to the air from described purifier a20, after processing, export cooling air 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, utilize ethylene glycol solution storage cold energy, when LNG cold energy supply is not enough, the glycol water of storage cold energy provides cold energy as cooling medium to intercooler a2 and aftercooler a4 in described air compressor machine, for cooling raw air.
The nitrogen that extract out at tower a13 top from described rectifying column divides two-way output, conducting when two-way is different when the supply of LNG cold energy and supply discontinuity, wherein a road is supplying at once as cooling medium, by valve, to input described main heat exchanger a12 when LNG cold energy, and another road is inputted 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 Fen San road output that extract out at tower a15 top from described rectifying column, conducting when first and second road and Third Road are different when the supply of LNG cold energy and supply discontinuity, when LNG cold energy is for seasonable, the first via is inputted described main heat exchanger a12 as cooling medium by valve and is carried out heat exchange, after heat exchange, inputting described LNG-nitrogen heat exchanger a6 carries out cooling, after cooling, input again described nitrogen pressure compression system, the second tunnel is inputted described LNG-nitrogen heat exchanger a6 by valve and is carried out coolingly, inputs described nitrogen pressure compression system after cooling again; When LNG cold energy interrupts, Third Road is inputted described external heat exchanger a22 as cooling medium by valve, exports external equipment after heat exchange to.
Described refrigeration compression system also comprises liquid nitrogen-nitrogen heat exchanger a9, the nitrogen of described nitrogen pressure compression system output forms cryogenic high pressure nitrogen after described LNG-nitrogen heat exchanger a6 is cooling, after described liquid nitrogen-nitrogen heat exchanger a9 is further cooling, output liquid nitrogen, from the liquid nitrogen of described liquid nitrogen-nitrogen heat exchanger a9 output, input described the first gas-liquid separator a10, the nitrogen of described the first gas-liquid separator a10 separation and from described liquid nitrogen-nitrogen heat exchanger a9 output anti-flow liquid nitrogen as cooling medium, input respectively described liquid nitrogen-nitrogen heat exchanger a9, after heat exchange, all as cooling medium, input to described LNG-nitrogen heat exchanger a6, after heat exchange, input described nitrogen pressure compression system.
Described nitrogen pressure compression system comprises low-temp low-pressure circulating nitrogen gas compressor a7 and cryogenic high pressure circulating nitrogen gas compressor a8, from the nitrogen of described LNG-nitrogen heat exchanger a6 output, pass through successively 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, through twice compression and cooling after output.
Described space division system also comprises subcooler a16, the liquid nitrogen of described rectifying column condenser/evaporator a14 output, the liquid nitrogen fraction 16 of tower a15 top output under described rectifying column, the oxygen-enriched liquid air of tower a15 bottom output under the lean solution empty 18 of tower a15 bottom output under described rectifying column and described rectifying column, after described subcooler a16 heat exchange, input respectively described upper tower a13, the dirty nitrogen 55 of the nitrogen of described upper tower a13 top output and the output of described upper tower a13 top converges after described subcooler a16 heat exchange, divide again two-way output, wherein a road is supplying at once as cooling medium, by valve, to input described main heat exchanger a12 when LNG cold energy, and another road is inputted 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, from the air of described purifier a20 output, after described main heat exchanger a12 heat exchange, be divided into two-way, wherein described rectifying column is directly inputted on a road, another road is after described cyclic nitrogen-air heat exchanger a21 heat exchange, input described rectifying column, from the isolated liquid nitrogen of described the 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 cut tower a13 from described extracts out at middle part, input described crude argon column a17 and remove oxygen formation process argon wherein, the nitrogen that the described pure argon column a18 of described process argon 44 input removes wherein forms seminal fluid argon, as finished product, sends into storage tank; Under described rectifying column, tower a15 extracts bottom oxygen-enriched liquid air out and splits into two-way, and wherein described upper tower a13 is inputted on a road, inputs the overhead condenser of described crude argon column a17 after another road reducing pressure by regulating flow as cooling medium, inputs described upper tower a13 after heat exchange; Separately from described rectifying column, tower a15 extracts at top a road nitrogen out, passes through successively evaporimeter and overhead condenser at the bottom of the tower of described pure argon column a18, inputs described upper tower a13 after heat exchange; The liquid nitrogen of the condenser/evaporator a14 output of described rectifying column is shunted after extracting out, the described upper tower a13 of part input, and another part is inputted the overhead condenser of described pure argon column a18 as cooling medium, input described upper tower a13 after heat exchange.
Advantage and good effect that the present invention has are: cooling system arranges two cover heat exchangers, according to LNG cold energy supply status, alternately put into operation, 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 opens when the supply discontinuity of LNG cold energy; According to LNG cold energy supply status, stop described LNG cold energy recovery system equipment operation, and adjust distillation system technical parameter simultaneously, 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, can maintain like this continuous and stable operation of space division system, solve the outer defeated load of LNG receiving station gasification and cold energy project demands nonsynchronous contradiction in time, avoid the frequent a series of losses of stopping and bringing of space division system; By LNG-ethylene glycol heat exchanger a5 is set, utilize ethylene glycol solution storage cold energy, when LNG cold energy supply is not enough, the glycol water of storage cold energy provides cold energy, for preliminary cooling raw air, the cold energy consumption while reducing LNG cold energy supply deficiency; Subcooler is set, the cold energy discharging 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 machine charge air cooler; 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 cut; 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.
The specific embodiment
For further understanding summary of the invention of the present invention, Characteristic, 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 moved 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, purify 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 after being compressed to cooling processing, the nitrogen of described distillation system formation forms liquid nitrogen, the liquid nitrogen that described Separate System of Water-jet forms described refrigeration compression system carries out gas-liquid separation processing, 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 forms, 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 forms, and it opens 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, when LNG cold energy is in liberal supply, increase finished product liquid nitrogen production, and when the supply discontinuity of LNG cold energy low load operation the liquid nitrogen that stops manufacturing a finished product, 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 as the external heat exchanger a22 of 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 to raw air A1 filter, compression and purified treatment, purification of compressed air after processing can be divided into two-way from described purifier a20 output, 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 cut-off, when the supply discontinuity of LNG cold energy, air B3 cut-off, air E54 conducting, 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 carries out cooling to the air from described purifier a20, after processing, export cooling air to described rectifying column, described rectifying column carries out fractionation to the air of input, form liquid oxygen and nitrogen, the nitrogen part that extract out at tower a15 top from described rectifying column discharges cold energy through described main heat exchanger a12, output after described LNG-nitrogen heat exchanger a6 is cooling again, the nitrogen of described LNG-nitrogen heat exchanger a6 output is inputted described nitrogen pressure compression system and is compressed, and become liquid nitrogen D34 after further cooling, through described the first gas-liquid separator a10 and described the second gas-liquid separator a11, carry out gas-liquid separation successively again, form nitrogen and finished product liquid nitrogen H41, wherein finished product liquid nitrogen H41 exports storage tank to, the nitrogen F40 of the second gas-liquid separator a11 separation is as cooling medium input main heat exchanger a12, 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 is inputted described external heat exchanger a22 as cooling medium, described external heat exchanger a22 carries out cooling to the air E54 from described purifier a20, after processing, export cooling air 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, utilize ethylene glycol solution storage 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 to intercooler a2 and aftercooler a4 in described air compressor machine, for cooling raw air.
The nitrogen that extract out at tower a13 top from described rectifying column can divide two-way output, conducting when two-way is different when the supply of LNG cold energy and supply discontinuity, wherein a road is being inputted described main heat exchanger a12 at once can be used as cooling medium by valve conducting when LNG cold energy, can be directly after heat exchange emptying or input described purifier a20 as regeneration gas, and can be used as cooling medium when LNG cold energy interrupts, another road nitrogen BC56 inputs described external heat exchanger a22 by valve conducting, also can be directly after heat exchange emptying or input described purifier a20 as regeneration gas, the nitrogen AA20 Ke Fen tri-tunnel outputs that extract out at tower a15 top from described rectifying column, be respectively: first via nitrogen AB27, the second road nitrogen AC28 and Third Road nitrogen AD58, first, conducting when two tunnels and Third Road are different when the supply of LNG cold energy and supply discontinuity, when LNG cold energy is for seasonable, Third Road nitrogen AD58 cut-off, first via nitrogen AB27, the second road nitrogen AC28 conducting, first via nitrogen AB27 can be used as cooling medium and by valve conducting, inputs described main heat exchanger a12 and carry out heat exchange, after heat exchange, inputting described LNG-nitrogen heat exchanger a6 carries out cooling, after cooling, input again described nitrogen pressure compression system, the second road nitrogen AC28 can input described LNG-nitrogen heat exchanger a6 by valve conducting and carry out cooling, after cooling, input again described nitrogen pressure compression system, when LNG cold energy interrupts, Third Road nitrogen AD58 conducting, first via nitrogen AB27, the second road nitrogen AC28 cut-off, Third 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 of described nitrogen pressure compression system output forms cryogenic high pressure nitrogen after described LNG-nitrogen heat exchanger a6 is cooling, can be after described liquid nitrogen-nitrogen heat exchanger a9 be further cooling, output liquid nitrogen D34 and liquid nitrogen DA35, from the liquid nitrogen D34 of described liquid nitrogen-nitrogen heat exchanger a9 output, input described the first gas-liquid separator a10, the nitrogen of described the first gas-liquid separator a10 separation and the liquid nitrogen DA35 instead flowing from described liquid nitrogen-nitrogen heat exchanger a9 output can be used as cooling medium and input respectively described liquid nitrogen-nitrogen heat exchanger a9, after heat exchange, all can be used as cooling medium and input to described LNG-nitrogen heat exchanger a6, after heat exchange, input described nitrogen pressure compression system.
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, from the nitrogen of described LNG-nitrogen heat exchanger a6 output, can pass through successively 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, through twice compression and cooling after export.
Described space division system also can comprise subcooler a16, the liquid nitrogen A13 of described rectifying column condenser/evaporator a14 output, the liquid nitrogen fraction 16 of tower a15 top output under described rectifying column, the oxygen-enriched liquid air A11 of tower a15 bottom output under the lean solution empty 18 of tower a15 bottom output under described rectifying column and described rectifying column, can after described subcooler a16 heat exchange, input respectively described upper tower a13, the dirty nitrogen 55 of the nitrogen BA22 of described upper tower a13 top output and the output of described upper tower a13 top can pass through described subcooler a16 heat exchange, after heat exchange, can converge for nitrogen BB23, nitrogen BB23 can divide two-way output again, wherein a road is being inputted described main heat exchanger a12 at once can be used as cooling medium by valve when LNG cold energy, and can be used as cooling medium when LNG cold energy interrupts, another road nitrogen BC56 inputs described external heat exchanger a22 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, from the air B3 of described purifier a20 output, after described main heat exchanger a12 heat exchange, can be divided into two-way, wherein described rectifying column can be directly inputted on a road, described in another Lu Kejing after cyclic nitrogen-air heat exchanger a21 heat exchange, input described rectifying column, from the isolated liquid nitrogen E37 of described the first gas-liquid separator a10, a part of liquid nitrogen F38 be can shunt and described cyclic nitrogen-air heat exchanger a21 and air heat-exchange inputted, remainder liquid nitrogen G39 inputs described the second gas-liquid separator a11.
Described space division system also can comprise crude argon column a17 and pure argon column a18, argon cut 25 tower a13 from described extracts out at middle part, input described crude argon column a17 and remove oxygen formation process argon 44 wherein, the nitrogen that the described pure argon column a18 of described process argon 44 input removes wherein forms seminal fluid argon 48, as finished product, sends into storage tank; Under described rectifying column, tower a15 extracts bottom oxygen-enriched liquid air A11 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, after the oxygen-enriched liquid air C43 reducing pressure by regulating flow of another road, as cooling medium, input the overhead condenser of described crude argon column a17, after heat exchange, input described upper tower a13; Separately from described rectifying column, tower a15 extracts at top a road nitrogen AE45 out, passes through successively evaporimeter and overhead condenser at the bottom of the tower of described pure argon column a18, inputs described upper tower a13 after heat exchange; The liquid nitrogen of the condenser/evaporator a14 output of described rectifying column is shunted after extracting out, be respectively liquid nitrogen A13 and liquid nitrogen I49, wherein liquid nitrogen I49 partly inputs described upper tower a13, liquid nitrogen A13 part is inputted 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 sending into pipe network, and its temperature is-145 ℃.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 moves under normal design operating mode; When night, seldom even gasification was not loaded, the cold demand of use of LNG cold energy air separation unit can not meet, when the supply of LNG cold energy is greater than setting, as the in liberal supply operating mode of LNG cold energy, process, when LNG cold energy supply less than or equal to set limiting value time, as LNG cold energy, interrupt operating mode and process, when the supply of LNG cold energy is greater than the limiting value of setting, as LNG cold energy supply nominal situation; Cold energy air separation unit need interrupt moving under operating mode at LNG cold energy, by methods such as external heat exchanger a22 and closing device and change device parameters, maintains air separation unit and moves continuously.
One normal design operating mode: the supply of LNG cold energy is normal
Flow is 49200Nm 3the raw air A1 of/hr removes after dust and mechanical admixture in filter a1, enter air compressor machine a3, air compressor machine a3 is air turbine compressor, 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 intercooler a2 and aftercooler a4 in described air compressor machine, for cooling raw air, raw air A1 is cooled to 10 ℃, 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 that goes out purifier a20 enters main heat exchanger a12 and is cooled to-171 ℃, main heat exchanger a12 low-temperature receiver is from the nitrogen AB27 at lower tower a15 top with from the nitrogen BB23 of 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 after-176 ℃ again.
At lower tower a15, its operating pressure is 0.56MPa, has compressed and has purified cooling air initial gross separation.Utilize that the concentration difference of uprising gas and lower flowing liquid and component are poor carries out caloic exchange, lower boiling nitrogen is evaporated, and high boiling oxygen is condensed, and through condensation and the evaporation of multistage column plate, in lower tower a15 tower reactor, forms oxygen-enriched liquid air.At lower tower a15 tower top, form high-purity nitrogen, most of the nitrogen steam, through main condenser evaporimeter a14, carries out heat exchange with upper tower a13 bottom liquid oxygen, 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 ℃, 0.56MPa, excessively be chilled to-186 ℃ in subcooler a16 after, be divided into two-way, be respectively liquid nitrogen B14 and liquid nitrogen C15, in the liquid nitrogen B14 input that wherein a road flow is 587kg/hr, tower a13 is as the phegma of upper tower a13; The first throttling of an other road liquid nitrogen C15 is depressurized to 0.15MPa, then goes pure argon column a18 overhead condenser that cold is provided, and its outlet temperature is-192 ℃, the upper tower a13 of input afterwards.
From lower tower a15 bottom, extract the oxygen-enriched liquid air A11 of 30337kg/hr out, its temperature is-173 ℃, excessively be chilled to-177 ℃ in subcooler a16 after, split into oxygen-enriched liquid air B42 and oxygen-enriched liquid air C43, in the oxygen-enriched liquid air B42 input that wherein flow is 13100kg/hr, tower a13 is 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 of inputting crude argon column a17 provides cold, and its outlet temperature is-185 ℃, the upper tower a13 of input afterwards.Lower tower a15 top is extracted 9731kg/hr, the liquid nitrogen fraction 16 of-177 ℃, lower tower a15 bottom out and is taken out 5435kg/hr, the lean solution sky 18 of-175 ℃, in subcooler a16, cross and be chilled to-190 ℃ ,-178 ℃ respectively, 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.
From lower tower a15 top, extract two-way nitrogen out, one road 525kg/hr, the nitrogen AE45 of-177 ℃, evaporimeter at the bottom of the tower of input pure argon column a18, an other road 33620kg/hr, the nitrogen AA20 of-177 ℃, split into three tunnels, be respectively nitrogen AB27, nitrogen AC28 and nitrogen AD58, nitrogen AB27 wherein, nitrogen AC28 is in LNG cold energy supply conducting, nitrogen AD58 ends for seasonable at LNG cold energy, the nitrogen AB27 that wherein flow is 24122kg/hr is warming up to after 14 ℃ through main heat exchanger a12, input LNG-nitrogen heat exchanger a6, nitrogen AC28 is through liquid nitrogen-nitrogen heat exchanger a9 in addition, be warming up to-144 ℃ of laggard LNG-nitrogen heat exchanger a6, 12860kg/hr, the liquid oxygen 21 of-180 ℃ is extracted out from main condenser evaporimeter a14, as finished product cooling box, send into storage tank.
From upper tower a13 top, extracting temperature out is-192 ℃, pressure is 0.13MPa, flow is the nitrogen BA22 of 14523kg/hr, from upper tower a13 top, extracting temperature out is-192 ℃, pressure is 0.13MPa, flow is the dirty nitrogen 55 of 8905kg/hr, input respectively subcooler a16, in subcooler a16 with liquid nitrogen A13, liquid nitrogen fraction 16, lean solution empty 18 and oxygen-enriched liquid air A11 carry out heat exchange, after exchange, be merged into as the nitrogen BB23 of-175 ℃, nitrogen BB23 is divided into two-way, wherein a road is nitrogen BC56, at LNG cold energy, for seasonable, end, conducting input external heat exchanger a22 when the supply discontinuity of LNG cold energy, end when the supply discontinuity of LNG cold energy on an other road, at LNG cold energy, supplies seasonable conducting and input main heat exchanger a12 to be warming up to 14 ℃ of outputs, and a nitrogen part for output goes purifier a20 as regeneration gas, and remainder is emptying.
The argon cut 25 of 14951kg/hr ,-180 ℃ and 0.14MPa is extracted out and is sent into crude argon column a17 from upper tower a13 middle part, and the operating pressure of crude argon column a17 is 0.13MPa, removes oxygen wherein in crude argon column a17, obtains process argon 44.410kg/hr, the process argon 44 of-183 ℃ are sent 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 ℃ in the bottom of pure argon column a18, as finished product, send into storage tank.
Flow is that 58197kg/hr's the LNG of-145 ℃ gasifies, heats up in LNG-nitrogen heat exchanger a6, a part is warming up to environment temperature, 51002kg/hr, the LNG of-70 ℃ 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 ℃ 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 ℃ of laggard LNG-nitrogen heat exchanger a6, the two all converges output nitrogen C31 in LNG-nitrogen heat exchanger a6 after heat exchange, by low-temp low-pressure circulating nitrogen gas compressor, a7 is compressed to 2.3MPa, and then by cryogenic high pressure circulating nitrogen gas compressor a8, is compressed to 7MPa and becomes nitrogen D33.Liquid nitrogen DA35 heat exchange, liquefaction that nitrogen D33 input liquid nitrogen-nitrogen heat exchanger a9 and throttling are backflowed, liquid nitrogen D34 throttling in the first gas-liquid separator a10 is separated, the liquid nitrogen E37 of a10 bottom splits into two-way, be respectively liquid nitrogen F38 and liquid nitrogen G39, wherein 18372kg/hr, liquid nitrogen F38 input cyclic nitrogen-air heat exchanger a21 and the air heat-exchange of-192 ℃, pass to fractionating system by cold; Another liquid nitrogen G39 sends into the second gas-liquid separator a11 and carries out gas-liquid separation, 12677kg/hr, the liquid nitrogen H41 of-192 ℃ send into storage tank as liquid nitrogen finished product, the separated nitrogen F40 generating of the second gas-liquid separator a11, input main heat exchanger a12, after heat exchange, input external equipment, 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 intercooler a2 and aftercooler a4 in described air compressor machine, for cooling raw air, raw air A1 is cooled to 10 ℃, 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 that goes out purifier a20 enters external heat exchanger a22 and is cooled to-174 ℃, the low-temperature receiver of external heat exchanger a22 is except upper tower a13 tower top nitrogen BC56 and lower tower a15 top nitrogen AD58, also need 10000kg/hr, the storage tank finished product liquid nitrogen 60 of-192 ℃ that cold energy is provided, storage tank liquid nitrogen is from finished product liquid nitrogen H41.
At lower tower a15, its operating pressure is 0.56MPa, cooling air initial gross separation.Utilize that the concentration difference of uprising gas and lower flowing liquid and component are poor carries out caloic exchange, lower boiling nitrogen is evaporated, and high boiling oxygen is condensed, and through condensation and the evaporation of multistage column plate, in lower tower a15 tower reactor, forms oxygen-enriched liquid air.At lower tower a15 tower top, form high-purity nitrogen, most of the nitrogen steam, through main condenser evaporimeter a14, carries out heat exchange with upper tower a13 bottom liquid oxygen, and liquid oxygen is evaporated, and nitrogen steam is condensed and forms liquid nitrogen and extract out, extract liquid nitrogen I49 out and partly 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 ℃, 0.56MPa, excessively be chilled to-186 ℃ in subcooler a16 after, be divided into two-way and be respectively liquid nitrogen B14 and liquid nitrogen C15, the liquid nitrogen B14 that a road flow is 462kg/hr sends into tower a13 as the phegma of upper tower a13; The first throttling of an other road liquid nitrogen C15 is depressurized to 0.15MPa, then goes the overhead condenser of pure argon column a18 that cold is provided, and its outlet temperature is-192 ℃, returns to afterwards tower a13.
From lower tower a15 bottom, extract the oxygen-enriched liquid air A11 of 29140kg/hr out, its temperature is-174 ℃, in subcooler a16, cross and be chilled to-179 ℃, being divided into two-way is oxygen-enriched liquid air B42 and oxygen-enriched liquid air C43, in the oxygen-enriched liquid air B42 input that wherein flow is 12095kg/hr, tower a13 is as phegma, and the first throttling of the oxygen-enriched liquid air C43 of another road 0.58MPa is depressurized to 0.15MPa, and the overhead condenser of then inputting crude argon column a17 provides cold for it, its outlet temperature is-187 ℃, the upper tower a13 of input afterwards.The 5347kg/hr that extract out the 10346kg/hr that extract out on lower tower a15 top, the liquid nitrogen fraction 16 of-177 ℃, lower tower a15 bottom, the lean solution sky 18 of-175 ℃, through subcooler a16, cross and be chilled to-190 ℃ ,-178 ℃ respectively, 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.
From lower tower a15 top, extract two-way nitrogen out, be respectively nitrogen AA20 and nitrogen AE45, a road 375kg/hr wherein, the nitrogen AE45 of-177 ℃, evaporimeter at the bottom of the tower of input pure argon column a18, 625kg/hr in addition, the nitrogen AA20 of-177 ℃, split into three tunnels, be respectively nitrogen AB27, nitrogen AC28 and nitrogen AD58, nitrogen AB27 wherein, nitrogen AC28 ends when the supply discontinuity of LNG cold energy, nitrogen AD58 conducting when the supply discontinuity of LNG cold energy, 625kg/hr, cooling-air E54 in the nitrogen AD58 input external heat exchanger a22 of-177 ℃, be warming up to 14 ℃ and export external equipment to.
9856kg/hr, the liquid oxygen 21 of-180 ℃ are extracted out from main condenser evaporimeter a14, as finished product, send into storage tank.
Flow is 35780kg/hr, temperature is-193 ℃, the pressure nitrogen BA22 that is 0.13MPa, from upper tower a13 top, extract out in subcooler a16 and carry out heat exchange with liquid nitrogen A13, liquid nitrogen fraction 16, lean solution empty 18 and oxygen-enriched liquid air A11, be warming up to-175 ℃, then enter external heat exchanger a22 and be warming up to 14 ℃, a part goes purifier a20 as regeneration gas, remaining emptying.
The argon cut 25 of 13423kg/hr ,-180 ℃ and 0.14MPa is extracted out and is sent into crude argon column a17 from upper tower a13 middle part, removes oxygen wherein in crude argon column a17, obtains process argon 44.232kg/hr, the process argon 44 of-183 ℃ are sent into pure argon column a18 and are removed nitrogen wherein, obtain 226kg/hr, the seminal fluid argon 48 of-183 ℃ in pure argon column a18 bottom, as finished product, send into storage tank.
Because LNG cold energy interrupts, will there is no the cooling ethylene glycol solution of LNG cold, so utilize daytime ethylene glycol solution storage cold when LNG cold energy is abundant, cold energy is directly used in the raw air after cooled compressed while interrupting.
Three recover nominal situation: the supply of LNG cold energy recovers normal
In LNG supply, recover the starting stage, its flow process and normal design operating mode are basic identical, and difference is now to increase the flow of lower column overhead nitrogen AA20, reaches 38370kg/hr, needs to increase the amount of vaporization of LNG simultaneously.Flow is that 60595kg/hr's the LNG of-145 ℃ gasifies, heats up in LNG-nitrogen heat exchanger a6, a part is warming up to environment temperature, 51002kg/hr, the LNG of-70 ℃ extract out and to export LNG-ethylene glycol heat exchanger a5 to from middle part in addition, remove cooling glycol water, two parts converge, send afterwards.By this operation, increase liquid nitrogen production, supplement the liquid nitrogen that consume when cold energy interrupts night.When liquid nitrogen liquid oxygen output reaches after balance, device can be returned to the operation of normal design operating mode.
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 that 5616kW cold is provided, and glycol-cooled needs 5912kW cold.In order to meet this two parts cold, need the LNG gasification cooling of 58t/h.Meanwhile, the merit that circulating nitrogen gas compression consumes is 2610kW.
B, under LNG cold energy supply discontinuity operating mode, utilizes liquid nitrogen cooling.The load reduction of air separation unit, to 75% of normal design operating mode, by changing technique, is made to not production fluid nitrogen simultaneously, thereby reduce required cold load at night.If the LNG cold energy supply discontinuity duration at night is 6 hours, known according to analog result: night, liquid oxygen output was 9.86 * 6=59.16t, and liquid nitrogen production is 0t, and liquid argon yield is 0.23 * 6=1.38t.External heat exchanger a22 needs liquid nitrogen that 1152kW cold is provided, and needs 10t/h liquid nitrogen.By 6 hours nights, calculated, need consume 60t liquid nitrogen during the supply discontinuity of LNG cold energy night.Although consumed liquid nitrogen night, such operation has maintained the continuous operation of cold energy air separation unit, and stops producing the compression power consumption that liquid nitrogen can be saved major part.
Glycol-cooled needs 4125kW cold, and this part cold is larger, so in liberal supply stage of LNG cold energy is by day cooled to ethylene glycol solution with LNG temperature requiredly, carries out Chu Leng.When the supply discontinuity of LNG cold energy, with the cold energy that low-temperature glycol solution stores, carry out the raw air after cooled compressed.
C recovers under nominal situation, by changing process reform product distribution situation, increases liquid nitrogen production, thereby supplements the liquid nitrogen consuming when night, LNG cold energy interrupted.If the in liberal supply duration of LNG cold energy is 18 hours, known according to analog result: daytime, liquid oxygen output was 9.59 * 18=172.62t/h, and liquid nitrogen production is 16.60 * 18=298.80t/h, and liquid argon yield is 0.26 * 18=4.68t/h.In LNG-nitrogen heat exchanger a6, need LNG that 6087kW cold is provided; And glycol-cooled needs 5912kW cold.In order to meet this two parts cold, need the LNG gasification cooling of 61t/h.Meanwhile, the merit that circulating nitrogen gas compression consumes is 2954kW.
D, when liquid nitrogen liquid oxygen output reaches after balance, can return to device the operation of normal design operating mode, utilizes LNG gasification cooling.
In a word, by external heat exchanger, utilize liquid nitrogen cooling, change of load and product distribution situation, can solve the outer defeated load of LNG receiving station gasification and cold energy project demands nonsynchronous contradiction in time simultaneously, ensures the continuous and stable operation of empty sub-item.
Although by reference to the accompanying drawings the preferred embodiments of the present invention are described above; but the present invention is not limited to the above-mentioned specific embodiment; the above-mentioned specific embodiment is only schematic; be not restrictive; those of ordinary skill in the art is under enlightenment of the present invention; not departing from the scope situation that aim of the present invention and claim protect, can also make a lot of forms, within these all belong to protection scope of the present invention.

Claims (9)

1. one kind makes space division system continuous method of moving 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, purify 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 after being compressed to cooling processing, the nitrogen of described distillation system formation forms liquid nitrogen, the liquid nitrogen that described Separate System of Water-jet forms described refrigeration compression system carries out gas-liquid separation processing, 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 forms, 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 forms, and it opens 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, when LNG cold energy is in liberal supply, increase finished product liquid nitrogen production, and when the supply discontinuity of LNG cold energy low load operation the liquid nitrogen that stops manufacturing a finished product, when the supply discontinuity of LNG cold energy, described refrigeration compression system and described Separate System of Water-jet are closed.
2. the space division system continuous method of operation during the supply discontinuity of LNG cold energy that makes 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 as the external heat exchanger (a22) of 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 to raw air A (1) filter, compression and purified treatment, purification of compressed air after processing is divided into two-way from described purifier (a20) output, conducting when two-way is different when the supply of LNG cold energy and supply discontinuity, the valve of leading up to is inputted described main heat exchanger (a12), and the valve of separately leading up to is inputted 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) carries out cooling to the air from described purifier (a20), after processing, export cooling air to described rectifying column, described rectifying column carries out fractionation to the air of input, form liquid oxygen and nitrogen, the nitrogen part that extract out at tower from described rectifying column (a15) top discharges cold energy through described main heat exchanger (a12), output after described LNG-nitrogen heat exchanger (a6) is cooling again, the nitrogen of described LNG-nitrogen heat exchanger (a6) output is inputted described nitrogen pressure compression system and is compressed, and become liquid nitrogen after further cooling, pass through successively more described the first gas-liquid separator (a10) and described the second gas-liquid separator (a11) carries out gas-liquid separation, form nitrogen and finished product liquid nitrogen, wherein finished product liquid nitrogen exports storage tank to, the separated nitrogen of the second gas-liquid separator (a11) is inputted 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 is inputted described external heat exchanger (a22) as cooling medium, described external heat exchanger (a22) carries out cooling to the air from described purifier (a20), after processing, export cooling air to described rectifying column, described rectifying column is set to low load operation.
3. the space division system continuous method of operation during the supply discontinuity of LNG cold energy that makes 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), utilize ethylene glycol solution storage cold energy, when LNG cold energy supply is not enough, the glycol water of storage cold energy provides cold energy as cooling medium to intercooler (a2) and aftercooler (a4) in described air compressor machine, for cooling raw air.
4. the space division system continuous method of operation during the supply discontinuity of LNG cold energy that makes according to claim 2, it is characterized in that, the nitrogen that extract out at tower from described rectifying column (a13) top divides two-way output, conducting when two-way is different when the supply of LNG cold energy and supply discontinuity, wherein a road is supplying at once as cooling medium, by valve, to input described main heat exchanger (a12) when LNG cold energy, and another road is inputted 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 Fen San road output that extract out at tower from described rectifying column (a15) top, conducting when first and second road and Third Road are different when the supply of LNG cold energy and supply discontinuity, when LNG cold energy is for seasonable, the first via is inputted described main heat exchanger (a12) as cooling medium by valve and is carried out heat exchange, after heat exchange, inputting described LNG-nitrogen heat exchanger (a6) carries out cooling, after cooling, input again described nitrogen pressure compression system, the second tunnel is inputted described LNG-nitrogen heat exchanger (a6) by valve and is carried out coolingly, inputs described nitrogen pressure compression system after cooling again, when LNG cold energy interrupts, Third Road is inputted described external heat exchanger (a22) as cooling medium by valve, exports external equipment after heat exchange to.
5. the space division system continuous method of operation during the supply discontinuity of LNG cold energy that makes according to claim 2, it is characterized in that, described refrigeration compression system also comprises liquid nitrogen-nitrogen heat exchanger (a9), nitrogen formation cryogenic high pressure nitrogen after described LNG-nitrogen heat exchanger (a6) is cooling of described nitrogen pressure compression system output, after described liquid nitrogen-nitrogen heat exchanger (a9) is further cooling, output liquid nitrogen, from the liquid nitrogen of described liquid nitrogen-nitrogen heat exchanger (a9) output, input described the first gas-liquid separator (a10), the nitrogen that described the first gas-liquid separator (a10) is separated and the liquid nitrogen instead flowing from described liquid nitrogen-nitrogen heat exchanger (a9) output are inputted respectively described liquid nitrogen-nitrogen heat exchanger (a9) as cooling medium, after heat exchange, all as cooling medium, input to described LNG-nitrogen heat exchanger (a6), after heat exchange, input described nitrogen pressure compression system.
6. the space division system continuous method of operation during the supply discontinuity of LNG cold energy that makes 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), from the nitrogen of described LNG-nitrogen heat exchanger (a6) output, pass through successively 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), through twice compression and cooling after export.
7. the space division system continuous method of operation during the supply discontinuity of LNG cold energy that makes according to claim 2, it is characterized in that, described space division system also comprises subcooler (a16), the liquid nitrogen of described rectifying column condenser/evaporator (a14) output, the liquid nitrogen fraction of tower under described rectifying column (a15) top output, the oxygen-enriched liquid air of tower (a15) bottom output under the lean solution sky of tower under described rectifying column (a15) bottom output and described rectifying column, after described subcooler (a16) heat exchange, input described upper tower (a13) respectively, the dirty nitrogen of the nitrogen of described upper tower (a13) top output and the output of described upper tower (a13) top converges after described subcooler (a16) heat exchange, divide again two-way output, wherein a road is supplying at once as cooling medium, by valve, to input described main heat exchanger (a12) when LNG cold energy, and another road is inputted described external heat exchanger (a22) as cooling medium by valve when LNG cold energy interrupts.
8. the space division system continuous method of operation during the supply discontinuity of LNG cold energy that makes 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, from the air of described purifier (a20) output, after described main heat exchanger (a12) heat exchange, be divided into two-way, wherein described rectifying column is directly inputted on a road, another road is after described cyclic nitrogen-air heat exchanger (a21) heat exchange, input described rectifying column, from the isolated liquid nitrogen of described the 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 space division system continuous method of operation during the supply discontinuity of LNG cold energy that makes according to claim 2, it is characterized in that, described space division system also comprises crude argon column (a17) and pure argon column (a18), extract out at argon cut tower (a13) middle part from described, input described crude argon column (a17) and remove oxygen formation process argon wherein, described process argon is inputted described pure argon column (a18) and is removed nitrogen formation seminal fluid argon wherein, as finished product, sends into storage tank; Tower under described rectifying column (a15) bottom is extracted oxygen-enriched liquid air out and is split into two-way, wherein described upper tower (a13) is inputted on a road, after another road reducing pressure by regulating flow, as cooling medium, input the overhead condenser of described crude argon column (a17), after heat exchange, input described upper tower (a13); Separately from described rectifying column, a road nitrogen is extracted at tower (a15) top out, passes through successively evaporimeter and overhead condenser at the bottom of the tower of described pure argon column (a18), inputs described upper tower (a13) after heat exchange; The liquid nitrogen of the condenser/evaporator of described rectifying column (a14) output is shunted after extracting out, part input described upper tower (a13), another part is inputted the overhead condenser of described pure argon column (a18) as cooling medium, input described upper tower (a13) after heat exchange.
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