JP4276520B2 - Operation method of air separation device - Google Patents

Operation method of air separation device Download PDF

Info

Publication number
JP4276520B2
JP4276520B2 JP2003370739A JP2003370739A JP4276520B2 JP 4276520 B2 JP4276520 B2 JP 4276520B2 JP 2003370739 A JP2003370739 A JP 2003370739A JP 2003370739 A JP2003370739 A JP 2003370739A JP 4276520 B2 JP4276520 B2 JP 4276520B2
Authority
JP
Japan
Prior art keywords
lng
nitrogen
natural gas
liquefied natural
cold
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
JP2003370739A
Other languages
Japanese (ja)
Other versions
JP2005134036A (en
Inventor
保 橋本
隆司 大山
斉 浅岡
好美 滝口
潤一 中川
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kobe Steel Ltd
Original Assignee
Kobe Steel Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kobe Steel Ltd filed Critical Kobe Steel Ltd
Priority to JP2003370739A priority Critical patent/JP4276520B2/en
Priority to TW093131546A priority patent/TWI270644B/en
Priority to KR1020040086496A priority patent/KR100618735B1/en
Publication of JP2005134036A publication Critical patent/JP2005134036A/en
Application granted granted Critical
Publication of JP4276520B2 publication Critical patent/JP4276520B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • 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
    • F25J3/04521—Coupling of the air fractionation unit to an air gas-consuming unit, so-called integrated processes
    • F25J3/04612—Heat exchange integration with process streams, e.g. from the air gas consuming unit
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/0002—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the fluid to be liquefied
    • F25J1/0022—Hydrocarbons, e.g. natural gas
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
    • F25J1/0047—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle
    • F25J1/005—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle by expansion of a gaseous refrigerant stream with extraction of work
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/006—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the refrigerant fluid used
    • F25J1/007—Primary atmospheric gases, mixtures thereof
    • F25J1/0072—Nitrogen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
    • F25J1/0203—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a single-component refrigerant [SCR] fluid in a closed vapor compression cycle
    • F25J1/0204—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a single-component refrigerant [SCR] fluid in a closed vapor compression cycle as a single flow SCR cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
    • F25J1/0228—Coupling of the liquefaction unit to other units or processes, so-called integrated processes
    • F25J1/0234—Integration with a cryogenic air separation unit
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
    • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
    • F25J1/0285—Combination of different types of drivers mechanically coupled to the same refrigerant compressor, possibly split on multiple compressor casings
    • F25J1/0288—Combination of different types of drivers mechanically coupled to the same refrigerant compressor, possibly split on multiple compressor casings using work extraction by mechanical coupling of compression and expansion of the refrigerant, so-called companders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
    • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
    • F25J1/0292—Refrigerant compression by cold or cryogenic suction of the refrigerant gas
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • 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
    • F25J3/04187—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
    • 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
    • F25J3/04357—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 and comprising a gas work expansion loop
    • 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
    • F25J2210/00—Processes characterised by the type or other details of the feed stream
    • F25J2210/90—Boil-off gas from storage
    • 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
    • F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
    • F25J2290/34—Details about subcooling of liquids

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Separation By Low-Temperature Treatments (AREA)
  • Filling Or Discharging Of Gas Storage Vessels (AREA)

Description

本発明は、特に、液化天然ガス（以下、ＬＮＧという。）の冷熱を利用して、大気から取り込んだ原料空気を窒素と酸素とに分離する空気分離装置の運転方法に関するものである。 The present invention is particularly, liquefied natural gas using a cold (hereinafter, referred to as LNG.), Relates to an operation method of an air separation equipment to separate the feed air taken from the atmosphere into nitrogen and oxygen.

周知のとおり、空気分離装置は空気中の窒素と酸素とを分離して取出すものであり、圧縮・冷却・膨張サイクルからなる寒冷発生装置を備えている。このような寒冷発生装置に加えて、ＬＮＧの冷熱を利用することによって、空気の分離、および液体製品（液体酸素、液体窒素、液体アルゴン等）の製造に必要な圧縮動力を大幅に低減させるようにした空気分離装置がある。このような空気分離装置としては、例えば、その系統図の図１０に示すような構成になるものが公知である。以下、この従来例に係る空気分離装置の概要を、その系統図の図１０を参照しながら説明する。   As is well known, the air separation device separates and extracts nitrogen and oxygen from the air, and includes a cold generator comprising a compression / cooling / expansion cycle. In addition to such a cold generator, the compressive power required for air separation and production of liquid products (liquid oxygen, liquid nitrogen, liquid argon, etc.) is greatly reduced by utilizing the cold heat of LNG. There is an air separation device. As such an air separation device, for example, a device having a configuration as shown in FIG. Hereinafter, the outline of the air separation device according to this conventional example will be described with reference to FIG.

図に示す符号５０は、従来例に係る空気分離装置である。この従来例に係る空気分離装置５０の場合、図示しない吸着塔等で前処理（水分や炭酸ガス等を除去する。）された原料ガスは、主熱交換器５１を通じて精留塔高圧塔（以下、高圧精留塔という。）５２Ｈ内に導入される。そして、この高圧精留塔５２Ｈ内の底部から精留塔低圧塔（以下、低圧精留塔という。）５２Ｌの中腹部に酸素リッチの液体空気が送られると共に、高圧精留塔５２Ｈの上段から低圧精留塔５２Ｌの塔頂に液体窒素が送られる。低圧精留塔５２Ｌの塔底液は、弁５３を通じて製品酸素として図示しない液体酸素タンク内に取出される。   Reference numeral 50 shown in the figure is an air separation device according to a conventional example. In the case of the air separation device 50 according to this conventional example, the raw material gas that has been pretreated (removes moisture, carbon dioxide gas, etc.) in an adsorption tower (not shown) is passed through the main heat exchanger 51 to the rectification tower high-pressure tower (hereinafter referred to as the rectification tower high-pressure tower). This is referred to as a high-pressure rectification column). Then, oxygen-rich liquid air is sent from the bottom of the high pressure rectification column 52H to the middle part of the rectification column low pressure column (hereinafter referred to as low pressure rectification column) 52L, and from the upper stage of the high pressure rectification column 52H. Liquid nitrogen is sent to the top of the low pressure rectification column 52L. The bottom liquid of the low pressure rectification column 52L is taken out as product oxygen through a valve 53 into a liquid oxygen tank (not shown).

一方、前記低圧精留塔５２Ｌの塔頂ガス（窒素ガス）は、前記主熱交換器５１で前記前処理済の原料ガスと熱交換した後、窒素予冷器５４、窒素冷却器５５、複数段の循環圧縮機５６、および窒素凝縮器５７を順に通って凝縮し、液窒分離器５８で気液分離される。液窒分離器５８の気相成分は、前記窒素凝縮器５７および窒素冷却器５５を通じて循環圧縮機５６に戻される一方、液相成分は空気分離装置５０に液体窒素として還元される。より具体的には、当該液体窒素の一部は弁６０を通じて前記高圧精留塔５２Ｈ内に還元され、残りは弁５９を通じて図示しない液体窒素タンク内に取出される。   On the other hand, the top gas (nitrogen gas) of the low-pressure rectification column 52L is subjected to heat exchange with the pretreated raw material gas in the main heat exchanger 51, and then the nitrogen precooler 54, the nitrogen cooler 55, and a plurality of stages. The circulatory compressor 56 and the nitrogen condenser 57 are condensed in this order, and the liquid and nitrogen separator 58 performs gas-liquid separation. The vapor phase component of the liquid nitrogen separator 58 is returned to the circulating compressor 56 through the nitrogen condenser 57 and the nitrogen cooler 55, while the liquid phase component is reduced to the air separation device 50 as liquid nitrogen. More specifically, a part of the liquid nitrogen is reduced through the valve 60 into the high pressure rectification column 52H, and the rest is taken out through a valve 59 into a liquid nitrogen tank (not shown).

前記窒素予冷器５４、窒素冷却器５５、および窒素凝縮器５７は熱交換器であって、これらの熱交換器を通じて、図示しないＬＮＧ貯槽から抽出されるＬＮＧと窒素ガスとの熱交換が行われる。そして、この熱交換によってＬＮＧの昇温および蒸発と窒素ガスの凝縮とが同時に行われる（特許文献１参照。）。
特開２００２−２９５７９９号公報 The nitrogen precooler 54, the nitrogen cooler 55, and the nitrogen condenser 57 are heat exchangers, and heat exchange between LNG extracted from an LNG storage tank (not shown) and nitrogen gas is performed through these heat exchangers. . And by this heat exchange, the temperature rise and evaporation of LNG and the condensation of nitrogen gas are performed simultaneously (see Patent Document 1).
JP 2002-295799 A

ところで、上記従来例に係る空気分離装置の場合には、後述するような問題があった。（１）天然ガス（ＮＧ）の需要がなくなって払出しができなくなった場合には、循環圧縮機から吐出される圧縮ガスを冷却する中間冷却媒体がないため、循環圧縮機の運転を停止しなければならない。つまり、循環圧縮機の運転停止と、立ち上げ運転とを繰返さなければならず、空気分離装置の稼働率の低下を回避することができなかった。
（２）また、ＬＮＧの使用量が大きく変動するため、空気分離装置は最小のＬＮＧ使用可能量に合わせて設計しなければならず、ＬＮＧの冷熱を十分に有効活用することができなかった。
（３）さらに、運転停止中の入熱によりＬＮＧタンク内に残されているＬＮＧの気化により自然気化ガス（ＢＯＧ）が生じ、ＬＮＧタンクの内圧が上昇して危険であるため、ＬＮＧタンク内のＢＯＧを廃棄しなければならず、経済的に不利になるという問題があった。 By the way, in the case of the air separation device according to the conventional example, there is a problem as described later. (1) If there is no demand for natural gas (NG), and the gas cannot be discharged, there is no intermediate cooling medium for cooling the compressed gas discharged from the circulating compressor, so the operation of the circulating compressor must be stopped. I must. That is, the operation stop and the start-up operation of the circulating compressor have to be repeated, and a reduction in the operating rate of the air separation device cannot be avoided.
(2) Further, since the amount of LNG used varies greatly, the air separation device must be designed in accordance with the minimum usable amount of LNG, and the cold energy of LNG cannot be fully utilized effectively.
(3) Furthermore, natural vaporized gas (BOG) is generated due to vaporization of LNG remaining in the LNG tank due to heat input during operation stop, and the internal pressure of the LNG tank rises, which is dangerous. There was a problem that BOG had to be discarded, which was disadvantageous economically.

従って、本発明の目的は、ＮＧの払出しができなくなっても、運転を継続することができると共に、ＢＯＧの発生を防止することができ、しかもＬＮＧの冷熱を十分に有効活用することを可能ならしめる空気分離装置の運転方法を提供することである。 Therefore, the object of the present invention is to continue operation even when NG cannot be paid out, to prevent the occurrence of BOG, and to make it possible to fully utilize the cold heat of LNG. Tighten to provide a method of operating the air separation equipment.

本発明の請求項１に係る空気分離装置の運転方法が採用した手段は、ＬＮＧタンクから十分な量のＬＮＧを供給することができるときには、ＬＮＧの冷熱による圧縮窒素ガスの冷却および冷熱蓄熱器への前記ＬＮＧの冷熱の蓄熱をし、蓄熱後のＬＮＧはＬＮＧ加温器で気化させて天然ガスを製造する一方、ＬＮＧタンクから供給できるＬＮＧの供給量が少ないときには、ＬＮＧタンクからＬＮＧポンプを経て供給したＬＮＧの冷熱で圧縮窒素ガスを冷却して自らは昇温して１部または全てがガス化するこのＬＮＧまたはＮＧを、ＬＮＧタンクからＬＮＧポンプを経て供給したＬＮＧに合流させてＬＮＧの２相流とした後に、前記冷熱蓄熱器に流入させて２相流のＬＮＧを液化することで冷熱を回収すると共に、冷熱回収後のＬＮＧを前記ＬＮＧタンクに戻すことを特徴とするものである。 Means for operating method is adopted in an air separation apparatus according to claim 1 of the present invention, when it is possible to supply a sufficient amount of LNG from the LNG tank, the compressed nitrogen gas by LNG cold heat cooling and the cold heat regenerator The LNG is stored with cold heat, and the LNG after the heat storage is vaporized with an LNG heater to produce natural gas. On the other hand, when the supply amount of LNG that can be supplied from the LNG tank is small, the LNG tank passes through the LNG pump. LNG or NG, which is partly or entirely gasified by cooling the compressed nitrogen gas with the cold heat of the supplied LNG, is gasified by one part or all, and merged with the LNG supplied from the LNG tank via the LNG pump. After the phase flow, the cold energy is recovered by flowing into the cold heat storage device and liquefying the two-phase flow LNG, and the LNG after the cold heat recovery is converted into the LNG. It is characterized in that the return to the tank.

本発明の請求項２に係る空気分離装置の運転方法が採用した手段は、請求項１に記載の空気分離装置の運転方法において、前記冷熱回収後のＬＮＧをＬＮＧタンクに戻す前に、窒素循環冷却機構で発生する寒冷を利用して冷却することを特徴とするものである。 The means employed by the operation method of the air separation device according to claim 2 of the present invention is the operation method of the air separation device according to claim 1 , wherein the LNG after the cold recovery is returned to the LNG tank before returning to the LNG tank. It is characterized by cooling using the cold generated by the cooling mechanism.

本発明の請求項１または２に係る空気分離装置の運転方法によれば、ＮＧの需要が多い場合には冷熱蓄熱器へＬＮＧの冷熱の蓄熱および循環圧縮機で圧縮された圧縮窒素ガスをＬＮＧの冷熱で冷却して液体窒素の製造運転を実施することができる。また、ＮＧの需要がない場合でも冷熱蓄熱器に蓄熱した冷熱を利用することで循環圧縮機の運転を継続することができる。従って、従来例に係る空気分離装置と異なり、ＮＧの需要がなくなって払出しができなくなっても運転を継続することができるから、空気分離装置の稼働率が向上し、液体窒素の生産性の向上に寄与することができる。また、ＬＮＧタンクに戻るＬＮＧを窒素循環冷却機構で発生する寒冷で過冷却してＬＮＧタンクに戻すことでＬＮＧタンク内のＬＮＧが冷却され、ＢＯＧの発生を抑制することができるから、ＢＯＧを廃棄する必要がなくなる。 According to the method of operating an air separator according to claim 1 or 2 of the present invention, the compressed nitrogen gas in many cases demand NG compressed with cold regenerator to the LNG cold heat regenerator and recycle compressor LNG The liquid nitrogen production operation can be carried out by cooling with the cold heat. Further, even when there is no demand for NG, the operation of the circulating compressor can be continued by using the cold energy stored in the cold energy regenerator. Therefore, unlike the conventional air separation apparatus, since the operation can be continued even if the demand for NG is lost and it becomes impossible to dispense, the operating rate of the air separation apparatus is improved and the productivity of liquid nitrogen is improved. Can contribute. Also, LNG returned to the LNG tank is supercooled by the cold generated by the nitrogen circulation cooling mechanism and returned to the LNG tank, so that the LNG in the LNG tank is cooled and the generation of BOG can be suppressed, so the BOG is discarded. There is no need to do it.

以下、本発明の空気分離方法を実施する空気分離装置を、添付図面を参照しながら説明する。図１は本発明の形態1に係る空気分離装置の模式的系統図、図２は本発明の形態1に係る空気分離装置の原料空気処理部の模式的系統説明図、図３は本発明の形態１に係る空気分離装置のコールドボックスと液体窒素過冷却部のコールドボックスとの模式的系統説明図、図４は本発明の形態１に係る空気分離装置の窒素循環冷却機構の模式的系統説明図である。各図に記載されている温度は、各機器類の出入口におけるＬＮＧまたはＮＧの温度である。   Hereinafter, an air separation apparatus for carrying out the air separation method of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic system diagram of an air separation device according to Embodiment 1 of the present invention, FIG. 2 is a schematic system explanatory view of a raw material air treatment unit of the air separation device according to Embodiment 1 of the present invention, and FIG. FIG. 4 is a schematic system explanatory view of the cold box of the air separation device according to the first embodiment and the cold box of the liquid nitrogen supercooling unit, and FIG. 4 is a schematic system description of the nitrogen circulation cooling mechanism of the air separation device according to the first embodiment of the present invention. FIG. The temperature described in each figure is the temperature of LNG or NG at the entrance / exit of each device.

本発明の形態１に係る空気分離装置は、主として後述する４つの主要部から構成されている。第１の主要部は、大気から原料空気を取り込んで所定圧力まで圧縮すると共に、圧縮空気を浄化する原料空気処理部１である。第２の主要部は、主熱交換器と、精留塔と、過冷却器等を収容したコールドボックス２である。また、第３の主要部は、前記コールドボックス２から排出された窒素ガスを圧縮すると共に、圧縮された窒素ガスをＬＮＧ利用熱交換器と、膨張タービンとで冷却して液体窒素を製造する窒素循環冷却機構３である。
そして、第４の主要部は、前記窒素循環冷却機構３で製造された液体窒素と低温の窒素ガスとを分離すると共に、液体窒素を過冷却して液体窒素製品とする液体窒素過冷却ボックス４である。以下、本発明の形態に係る空気分離装置を構成する、これら主要部の構成を、図面を順次参照しながら説明する。 The air separation device according to Embodiment 1 of the present invention is mainly composed of four main parts described later. The first main part is a raw air processing unit 1 that takes in raw air from the atmosphere and compresses it to a predetermined pressure and purifies the compressed air. The second main part is a cold box 2 containing a main heat exchanger, a rectifying column, a supercooler and the like. The third main part compresses the nitrogen gas discharged from the cold box 2, and cools the compressed nitrogen gas with an LNG heat exchanger and an expansion turbine to produce liquid nitrogen. This is a circulation cooling mechanism 3.
The fourth main part separates the liquid nitrogen produced by the nitrogen circulation cooling mechanism 3 from the low-temperature nitrogen gas, and supercools the liquid nitrogen to form a liquid nitrogen product, thereby producing a liquid nitrogen product. It is. Hereinafter, the structure of these main parts constituting the air separation device according to the embodiment of the present invention will be described with reference to the drawings sequentially.

前記原料空気処理部１は、図２に示すように構成されている。即ち、吸込フィルタ１１を介して大気から空気圧縮機１２に吸込まれた原料空気は、この空気圧縮機１２で所定圧力、例えば０．６ＭＰａまで圧縮される。この空気圧縮機１２から吐出された原料空気は冷却媒体と熱交換するクーラ１３により冷却された後にＭＳ吸着器１４に導入され、水分や炭酸ガス等が除去される。ＭＳ吸着器１４は２個並列配設されており、通常、原料空気は何れか一方のＭＳ吸着器１４に導入され、他方の使用に供されないＭＳ吸着器１４の図示しない吸着剤は、再生電気ヒータ１５を通って加熱された窒素ガスによって吸着機能が再生された後、切り替えするように構成されている。   The raw material air processing unit 1 is configured as shown in FIG. That is, the raw material air sucked into the air compressor 12 from the atmosphere via the suction filter 11 is compressed to a predetermined pressure, for example, 0.6 MPa by the air compressor 12. The raw material air discharged from the air compressor 12 is cooled by a cooler 13 that exchanges heat with a cooling medium, and then introduced into the MS adsorber 14 to remove moisture, carbon dioxide, and the like. Two MS adsorbers 14 are arranged in parallel. Usually, the raw material air is introduced into one of the MS adsorbers 14 and the adsorbent (not shown) of the MS adsorber 14 not used for the other is regenerated electricity. The adsorption function is regenerated by the nitrogen gas heated through the heater 15 and then switched.

つまり、交互に使用することによって、ＭＳ吸着器１４の再生のために空気分離装置の運転を停止することのないように配慮されている。ＭＳ吸着器１４により水分や炭酸ガス等が除去された原料空気は、図２に示す流路Ａを介してコールドボックス２に送られるように構成されている。なお、前記再生電気ヒータ１５は、後述するコールドボックス２に収納されている低圧精留塔２２から、図２に示す流路Ｂを介して供給される窒素ガスを加熱し、この加熱した窒素ガスをＭＳ吸着器１４に供給することにより吸着剤を再生させるものである。そして、ＭＳ吸着器１４の吸着剤を再生した後の窒素ガスはサイレンサ１６から大気中に放出される。   That is, it is considered that the operation of the air separation device is not stopped for the regeneration of the MS adsorber 14 by using alternately. The raw material air from which moisture, carbon dioxide, etc. have been removed by the MS adsorber 14 is configured to be sent to the cold box 2 via the flow path A shown in FIG. The regenerative electric heater 15 heats the nitrogen gas supplied from the low-pressure rectification tower 22 housed in the cold box 2 described later through the flow path B shown in FIG. Is supplied to the MS adsorber 14 to regenerate the adsorbent. The nitrogen gas after regenerating the adsorbent of the MS adsorber 14 is released from the silencer 16 into the atmosphere.

前記コールドボックス２内には、図３の左側に示すような複数種の機器類が収容されている。これら機器類は、主熱交換器２１、上部の低圧精留塔２２、下部の高圧精留塔２３、および過冷却器２４である。即ち、前記原料空気処理部１で処理され、流路Ａを介して主熱交換器２１に送られた原料空気は、この主熱交換器２１で冷却される。そして、原料空気は、低圧精留塔２２の頂部から過冷却器２４を介して取出された高純度窒素ガス、低圧精留塔２２の上部付近から過冷却器２４を介して取出された低純度窒素ガス（前記ＭＳ吸着器１４に供給される。）、および高圧精留塔２３から取出された高純度窒素ガスと熱交換することにより冷却される。   In the cold box 2, a plurality of types of devices as shown on the left side of FIG. These devices are a main heat exchanger 21, an upper low pressure rectification tower 22, a lower high pressure rectification tower 23, and a supercooler 24. That is, the raw material air processed by the raw material air processing unit 1 and sent to the main heat exchanger 21 via the flow path A is cooled by the main heat exchanger 21. The raw air is a high-purity nitrogen gas taken out from the top of the low-pressure rectification tower 22 via the supercooler 24, and a low-purity taken out from the vicinity of the upper portion of the low-pressure rectification tower 22 via the supercooler 24. It is cooled by exchanging heat with nitrogen gas (supplied to the MS adsorber 14) and high-purity nitrogen gas taken out from the high-pressure rectification column 23.

前記主熱交換器２１を通過した冷却空気は、高圧精留塔２３の底部に供給される。この高圧精留塔２３に供給された冷却空気は、塔内を上昇する間に次第に窒素リッチになり、高圧精留塔２３の頂部では高純度窒素となる。高純度窒素の一部は、高圧精留塔２３からガス状で抜き出され、主熱交換器２１を通って加熱されて系外に送出される。残部は主凝縮器２６に導かれ、冷却、凝縮されて液体窒素となる。凝縮された液体窒素の一部は、高圧精留塔２３の上部より抜出され、前記過冷却器２４を通って過冷却され、減圧された後に低圧精留塔２２の頂部に供給される。残りの液体窒素は塔内を流下する間に次第に酸素リッチになり、高圧精留塔２３の底部に液体空気２５として溜まる。液体空気２５は、高圧精留塔２３から引出された後に、過冷却器２４で過冷却されて低圧精留塔２２の中部に導入される。   The cooling air that has passed through the main heat exchanger 21 is supplied to the bottom of the high-pressure rectification tower 23. The cooling air supplied to the high-pressure rectification tower 23 gradually becomes nitrogen-rich while rising in the tower, and becomes high-purity nitrogen at the top of the high-pressure rectification tower 23. Part of the high-purity nitrogen is withdrawn in the form of gas from the high-pressure rectification column 23, heated through the main heat exchanger 21, and sent out of the system. The remainder is led to the main condenser 26, cooled and condensed to become liquid nitrogen. Part of the condensed liquid nitrogen is withdrawn from the upper portion of the high pressure rectification column 23, supercooled through the supercooler 24, decompressed, and then supplied to the top of the low pressure rectification column 22. The remaining liquid nitrogen gradually becomes rich in oxygen while flowing down the tower, and accumulates as liquid air 25 at the bottom of the high pressure rectification tower 23. The liquid air 25 is drawn out from the high-pressure rectification column 23, is then supercooled by the supercooler 24, and is introduced into the middle portion of the low-pressure rectification column 22.

前記低圧精留塔２２の中部に導入された酸素リッチな液体空気２５は塔内を流下しながら次第に酸素が凝縮され、底部において高純度酸素となる。そして、この低圧精留塔２２の底部に溜まった液体酸素は、液体酸素製品として系外に取出されるようになっている。
一方、低圧精留塔２２の頂部から過冷却器２４を介して取出された高純度窒素ガス、および高圧精留塔２３から取出された高純度窒素ガスは主熱交換器２１において原料空気と熱交換した後、図３に示す流路Ｃ，Ｄを介して送出され、それぞれ窒素循環冷却機構３に送られる。 The oxygen-rich liquid air 25 introduced into the middle of the low-pressure rectification tower 22 is gradually condensed while flowing down through the tower, and becomes high-purity oxygen at the bottom. The liquid oxygen collected at the bottom of the low pressure rectification column 22 is taken out of the system as a liquid oxygen product.
On the other hand, the high-purity nitrogen gas taken out from the top of the low-pressure rectification tower 22 via the supercooler 24 and the high-purity nitrogen gas taken out from the high-pressure rectification tower 23 are heated in the main heat exchanger 21 with raw material air and heat. After the replacement, they are sent out through the channels C and D shown in FIG. 3 and sent to the nitrogen circulation cooling mechanism 3 respectively.

前記窒素循環冷却機構３は、図４に示すように構成されている。流路Ｃから窒素循環冷却機構３に送り込まれた窒素ガスは窒素圧縮機３１により、流路Ｄから導かれた窒素ガスの圧力と等しい圧力になるまで圧縮された後に、Ｄ流路から導かれた窒素ガスとが合流して、循環圧縮機３２に導かれるようになっている。循環圧縮機３２から吐出された窒素ガスは、窒素循環流路３３を循環するように構成されている。より詳しくは、循環圧縮機３２から吐出されて窒素循環流路３３を流れる窒素ガスは、ＬＮＧの冷熱を利用する第１ＬＮＧ利用熱交換器３３ａで冷却され、冷却された窒素ガスの大部分が膨張タービン３３ｂに至り、断熱膨張させられた窒素ガスは、ＬＮＧを過冷却するための第１窒素冷熱利用熱交換器３３ｃ、膨張タービン３３ｂに分岐されなかった残り窒素を液化させる第２窒素冷熱利用熱交換器３３ｄ、ＬＮＧの冷熱を利用して窒素を冷却する第２ＬＮＧ利用熱交換器３３ｅの順に循環するように構成されている。なお、第１ＬＮＧ利用熱交換器３３ａは、窒素圧縮機３１に吸込まれる窒素ガス、循環圧縮機３２に吸込まれる窒素ガスも冷却するようになっている。   The nitrogen circulation cooling mechanism 3 is configured as shown in FIG. The nitrogen gas sent from the channel C to the nitrogen circulation cooling mechanism 3 is compressed by the nitrogen compressor 31 until the pressure becomes equal to the pressure of the nitrogen gas guided from the channel D, and then introduced from the D channel. The nitrogen gas joins and is led to the circulating compressor 32. The nitrogen gas discharged from the circulation compressor 32 is configured to circulate through the nitrogen circulation channel 33. More specifically, the nitrogen gas discharged from the circulation compressor 32 and flowing through the nitrogen circulation passage 33 is cooled by the first LNG utilization heat exchanger 33a that utilizes the cold heat of the LNG, and most of the cooled nitrogen gas expands. The nitrogen gas that has reached the turbine 33b and is adiabatically expanded is a first nitrogen cold heat utilization heat exchanger 33c for supercooling the LNG, and a second nitrogen cold heat utilization heat that liquefies the remaining nitrogen that has not been branched to the expansion turbine 33b. It is comprised so that it may circulate in order of the 2nd LNG utilization heat exchanger 33e which cools nitrogen using the cold energy of exchanger 33d and LNG. In addition, the 1st LNG utilization heat exchanger 33a also cools the nitrogen gas sucked into the nitrogen compressor 31 and the nitrogen gas sucked into the circulation compressor 32.

また、前記窒素循環冷却機構３には、ＬＮＧタンク３５ａ、ＬＮＧポンプ３５ｂ、ＬＮＧの冷熱を蓄熱する冷熱蓄熱器３４ａを経てＬＮＧ加温器３７に連通するＬＮＧ冷熱蓄熱流路３４が設けられている。さらに、前記窒素循環冷却機構３には、ＬＮＧタンク３５ａ、ＬＮＧポンプ３５ｂ、第２ＬＮＧ利用熱交換器３３ｅ、第１ＬＮＧ利用熱交換器３３ａ、冷熱蓄熱器３４ａ、第１窒素冷熱利用熱交換器３３ｃを経てＬＮＧタンク３５ａに戻る冷熱回収流路３５が設けられている。そして、この冷熱回収流路３５の第１ＬＮＧ利用熱交換器３３ａから出た部分から、予冷器３３ｆを経由するＮＧ排出流路３６がＬＮＧ加温器３７に連通している。   The nitrogen circulation cooling mechanism 3 is provided with an LNG cold heat storage channel 34 that communicates with the LNG heater 37 through the LNG tank 35a, the LNG pump 35b, and a cold heat storage device 34a that stores the cold energy of the LNG. . Further, the nitrogen circulation cooling mechanism 3 includes an LNG tank 35a, an LNG pump 35b, a second LNG utilization heat exchanger 33e, a first LNG utilization heat exchanger 33a, a cold heat storage device 34a, and a first nitrogen cold heat utilization heat exchanger 33c. A cold heat recovery flow path 35 is provided that returns to the LNG tank 35a. An NG discharge channel 36 that passes through the precooler 33 f communicates with the LNG heater 37 from the portion of the cold heat recovery channel 35 that exits from the first LNG utilization heat exchanger 33 a.

ＮＧ排出流路３６とＬＮＧ冷熱蓄熱流路３４とは別々のＬＮＧ加温器に連通する構成であってもよい。ＬＮＧ加温器３７としては、例えば海水によるＯＲＶ（Ｏｐｅｎ Ｒａｃｋ Ｖａｐｏｒｉｚｅｒ）であってもよく、また循環水による蒸発器であってもよい。また、この場合、流路Ｃ，Ｄを介して窒素圧縮機３１および循環圧縮機３２に吸込まれる窒素ガスを予冷する予冷器３３ｆや第１ＬＮＧ利用熱交換器３３ａ、第２ＬＮＧ利用熱交換器３３ｅ、第１窒素冷熱利用熱交換器３３ｃ、第２窒素冷熱利用熱交換器３３ｄは各一体化設計してもよく、分割してもよい。なお、冷熱蓄熱器３４ａに用いる蓄熱剤の候補としては，Ｎ−ペンタン、Ｎ−ヘキサン、エタノール、メチルシクロヘキサン、１−プロパロール等を挙げることができる。   The NG discharge channel 36 and the LNG cold heat storage channel 34 may be configured to communicate with different LNG heaters. The LNG heater 37 may be, for example, an ORV (Open Rack Vaporizer) using seawater or an evaporator using circulating water. In this case, the precooler 33f, the first LNG utilizing heat exchanger 33a, and the second LNG utilizing heat exchanger 33e for precooling the nitrogen gas sucked into the nitrogen compressor 31 and the circulating compressor 32 through the flow paths C and D are used. The first nitrogen cold heat utilization heat exchanger 33c and the second nitrogen cold heat utilization heat exchanger 33d may be designed integrally or may be divided. In addition, N-pentane, N-hexane, ethanol, methylcyclohexane, 1-propalol, etc. can be mentioned as a candidate of the thermal storage agent used for the cold energy storage device 34a.

前記循環圧縮機３２で圧縮されると共に、前記第１ＬＮＧ利用熱交換器３３ａで冷却された窒素ガスの一部は、上記のとおり、膨張タービン３３ｂにより膨張させられるが、他の窒素ガスは、途中で分岐して第２ＬＮＧ利用熱交換器３３ｅ、第２窒素冷熱利用熱交換器３３ｄを通る流路Ｅを流れる間に冷却され、液体窒素となって図４に示す液体窒素過冷却ボックス４に送り込まれるように構成されている。   A part of the nitrogen gas compressed by the circulating compressor 32 and cooled by the first LNG utilization heat exchanger 33a is expanded by the expansion turbine 33b as described above. Is cooled while flowing through the flow path E passing through the second LNG utilization heat exchanger 33e and the second nitrogen cold utilization heat exchanger 33d, and is converted into liquid nitrogen and fed into the liquid nitrogen supercooling box 4 shown in FIG. It is configured to be.

前記液体窒素過冷却ボックス４の内部には、図３の右側に示すように、主として気液分離器４１と液体窒素過冷却器４２が収容されている。即ち、流路Ｅを介して前記窒素循環冷却機構３から供給される液体窒素は、気液分離器４１で低温の窒素ガス４６と液体窒素４７とに分離される。気液分離器４１で分離された窒素ガス４６の一部は低圧精留塔２２に送られ、残りは流路Ｆを介して膨張タービン３４から吐出される窒素ガスに合流する。一方、液体窒素４７は液体窒素過冷却器４２で過冷却されて液体窒素製品として系外に取出される。前記液体窒素４７の一部は気液分離器４１の流出口付近で分岐して高圧精留塔２４の頂部に送出される。   As shown on the right side of FIG. 3, a gas-liquid separator 41 and a liquid nitrogen supercooler 42 are mainly accommodated in the liquid nitrogen supercooling box 4. That is, the liquid nitrogen supplied from the nitrogen circulation cooling mechanism 3 via the flow path E is separated into the low-temperature nitrogen gas 46 and the liquid nitrogen 47 by the gas-liquid separator 41. A part of the nitrogen gas 46 separated by the gas-liquid separator 41 is sent to the low-pressure rectification tower 22, and the rest merges with the nitrogen gas discharged from the expansion turbine 34 via the flow path F. On the other hand, the liquid nitrogen 47 is supercooled by the liquid nitrogen supercooler 42 and taken out of the system as a liquid nitrogen product. A part of the liquid nitrogen 47 branches near the outlet of the gas-liquid separator 41 and is sent to the top of the high-pressure rectification column 24.

また、気液分離器４１の出口から液体窒素流路４３が分岐しており、この液体窒素流路４３を介して液体窒素の一部が液体窒素製品の過冷却に使用されるようになっている、前記液体窒素流路４３には、液体窒素製品となる液体窒素の温度を検出する液体窒素温度検出センサ４５の検出温度に基づいて開度が制御される流量制御弁４４が介装されると共に、前記液体窒素過冷却器４２を介して液体窒素製品となる液体窒素を過冷却するように構成されている。これにより、所定温度範囲内に過冷却された窒素製品が製造されることとなる。   Further, a liquid nitrogen channel 43 is branched from the outlet of the gas-liquid separator 41, and a part of the liquid nitrogen is used for supercooling the liquid nitrogen product through the liquid nitrogen channel 43. The liquid nitrogen flow path 43 is provided with a flow rate control valve 44 whose opening degree is controlled based on the temperature detected by the liquid nitrogen temperature detection sensor 45 that detects the temperature of liquid nitrogen as the liquid nitrogen product. At the same time, the liquid nitrogen that is the liquid nitrogen product is supercooled via the liquid nitrogen supercooler 42. Thereby, the nitrogen product supercooled within a predetermined temperature range will be manufactured.

本発明の形態１に係る窒素循環冷却機構３によれば、下記の２通りの運転を行うことができる。即ち、ＬＮＧタンク３５ａから供給できるＬＮＧの供給量が多いときには、第１，２ＬＮＧ利用熱交換器３３ａ，３３ｅによる圧縮窒素ガスの冷却と並行して、ＬＮＧ冷熱蓄熱流路３４にＬＮＧを供給してＬＮＧの冷熱を冷熱蓄熱器３４ａに蓄熱し、蓄熱後のＬＮＧをＬＮＧ加温器３７で気化させてＮＧを製造することができる。一方、ＬＮＧタンク３５ａから供給できるＬＮＧの供給量が少ないときには、ＬＮＧタンク３５ａからＬＮＧポンプ３５ｂを介して冷熱回収流路３５に供給したＬＮＧの冷熱で圧縮窒素ガスを冷却して、自らは昇温して１部または全部がガス化するこのＬＮＧまたはＮＧを、ＬＮＧタンク３５ａからＬＮＧポンプ３５ｂを介して供給したＬＮＧに合流させてＬＮＧの気液２相流にする。そして、このＬＮＧの気液２相流を前記冷熱蓄熱器３４ａに流入させて気液２相流を液化させることで冷熱を回収すると共に、冷熱回収後のＬＮＧを前記第１窒素冷熱利用熱交換器３３ｃで冷却してＬＮＧタンク３５ａに戻すことができる。なお、この場合には、断熱膨張させた窒素ガスの冷熱を利用するようにしているが、例えば窒素循環冷却機構３で得られる液体窒素の冷熱を利用することができる。   According to the nitrogen circulation cooling mechanism 3 according to Embodiment 1 of the present invention, the following two operations can be performed. That is, when the supply amount of LNG that can be supplied from the LNG tank 35a is large, LNG is supplied to the LNG cold heat storage passage 34 in parallel with the cooling of the compressed nitrogen gas by the first and second LNG utilization heat exchangers 33a and 33e. LNG can be produced by storing the cold energy of LNG in the cold energy regenerator 34 a and evaporating the LNG after the heat storage with the LNG heater 37. On the other hand, when the supply amount of LNG that can be supplied from the LNG tank 35a is small, the compressed nitrogen gas is cooled by the cold heat of the LNG supplied from the LNG tank 35a to the cold heat recovery flow path 35 via the LNG pump 35b, and the temperature rises itself. Then, this LNG or NG, which is partially or entirely gasified, is merged with the LNG supplied from the LNG tank 35a via the LNG pump 35b to make a gas-liquid two-phase flow of LNG. Then, the LNG gas-liquid two-phase flow is caused to flow into the cold heat storage device 34a to recover the cold heat by liquefying the gas-liquid two-phase flow, and the LNG after the cold heat recovery is exchanged with the first nitrogen cold heat. It can be cooled by the vessel 33c and returned to the LNG tank 35a. In this case, the cold heat of the nitrogen gas adiabatically expanded is used, but the cold heat of liquid nitrogen obtained by the nitrogen circulation cooling mechanism 3 can be used, for example.

本発明の形態１に係る空気分離装置によれば、下記の通の効果を得ることができる。
（１） ＮＧの需要がなくなって払出しができなくなった場合でも、ＬＮＧを冷熱回収流路３５に供給して循環させることにより循環圧縮機３２から吐出される圧縮窒素ガスを冷却することができる。つまり、従来のように、循環圧縮機３２の運転を停止する必要がなく、ＮＧの需要量の多少に拘らず運転を継続することができるから、空気分離装置の稼働率が向上する。
（２） また、ＬＮＧの使用量が大きく変動しても、空気分離装置を最小のＬＮＧ使用可能量に合わせて設計する必要がないので、ＬＮＧの冷熱を十分に有効活用することができる。
（３） さらに、ＬＮＧタンク３５ａから冷熱回収流路３５に供給されたＬＮＧは、冷熱蓄熱器３４ａに蓄熱されている冷熱を回収すると共に、第１窒素冷熱利用熱交換器３３ｃで過冷却されてＬＮＧタンク３５ａに戻される。従って、ＬＮＧの過冷却度によりＬＮＧタンク３５ａ内のＢＯＧの発生を抑制するか、またはＬＮＧタンク３５ａ内のＢＯＧを液化させてＬＮＧタンク３５ａの内圧を低下させることができる。そのため、ＬＮＧタンク３５ａ内のＢＯＧを廃棄する必要がなく、経済的に有利になる。 According to the air separation device of the first embodiment of the present invention, the following effects can be obtained.
(1) Even when the demand for NG disappears and the dispensing becomes impossible, the compressed nitrogen gas discharged from the circulating compressor 32 can be cooled by supplying LNG to the cold recovery flow path 35 and circulating it. That is, unlike the prior art, it is not necessary to stop the operation of the circulating compressor 32 and the operation can be continued regardless of the amount of demand for NG, so that the operating rate of the air separation device is improved.
(2) Even if the amount of LNG used varies greatly, it is not necessary to design the air separation device in accordance with the minimum amount of LNG that can be used, so that the cold energy of LNG can be used sufficiently effectively.
(3) Furthermore, the LNG supplied from the LNG tank 35a to the cold heat recovery passage 35 collects the cold heat stored in the cold heat storage device 34a and is supercooled by the first nitrogen cold heat use heat exchanger 33c. It is returned to the LNG tank 35a. Accordingly, the generation of BOG in the LNG tank 35a can be suppressed by the degree of supercooling of the LNG, or the internal pressure of the LNG tank 35a can be reduced by liquefying the BOG in the LNG tank 35a. Therefore, it is not necessary to discard the BOG in the LNG tank 35a, which is economically advantageous.

窒素循環冷却機構３の冷熱回収回路３５としては、窒素循環冷却機構３の模式的部分系統説明図（本発明の形態１に係る変形例１）の図５に示すように、ＬＮＧタンク３５ａに、ＬＮＧ供給元タンク３８ａ内のＬＮＧをＬＮＧ供給元ポンプ３８ｂで供給する構成にすることができる。また，この窒素循環冷却機構３の模式的部分系統説明図（本発明の形態１に係る変形例２）の図６に示すように、流路Ｃの高純度窒素ガスを窒素圧縮機３１で圧縮し、これに流路Ｄの高純度窒素ガスを混入させると共に、予冷器３３ｆ、第１ＬＮＧ利用熱交換器３３ａを介して循環圧縮機３２に供給する構成にすることができる。なお、循環圧縮機３２の吸込温度の設計によっては、必ずしも予冷器３３ｆを必要としないものである。   As the cold heat recovery circuit 35 of the nitrogen circulation cooling mechanism 3, as shown in FIG. 5 of the schematic partial system explanatory diagram of the nitrogen circulation cooling mechanism 3 (modification 1 according to the first embodiment of the present invention), The LNG in the LNG supply source tank 38a can be supplied by the LNG supply source pump 38b. Further, as shown in FIG. 6 of a schematic partial system explanatory diagram of the nitrogen circulation cooling mechanism 3 (Modification 2 according to Embodiment 1 of the present invention), the high-purity nitrogen gas in the flow path C is compressed by the nitrogen compressor 31. In addition, the high purity nitrogen gas in the flow path D can be mixed therein and supplied to the circulating compressor 32 via the precooler 33f and the first LNG utilization heat exchanger 33a. Depending on the design of the suction temperature of the circulating compressor 32, the precooler 33f is not necessarily required.

本発明の形態２に係る空気分離装置を、その窒素循環冷却機構の模式的系統説明図の図７を参照しながら説明する。なお、本発明の形態２に係る空気分離装置の原料空気処理部、コールドボックス、液体窒素過冷却ボックスの構成は、上記形態１に係る空気分離装置と同構成であって、窒素循環冷却機構が相違するだけであるから、同一のものに同一符号を付し、かつ同一名称を以ってその相違する点について説明する、   An air separation device according to Embodiment 2 of the present invention will be described with reference to FIG. 7 of a schematic system explanatory view of the nitrogen circulation cooling mechanism. The configuration of the raw air processing unit, the cold box, and the liquid nitrogen supercooling box of the air separation device according to the second embodiment of the present invention is the same as that of the air separation device according to the first embodiment, and the nitrogen circulation cooling mechanism is Since they are only different, the same reference numerals are assigned to the same items, and the different points are described with the same names.

本発明の形態２に係る空気分離装置の窒素循環冷却機構３では、窒素循環流路３３の循環圧縮機３２の下流側に、前記循環圧縮機３２により圧縮されると共に、第１ＬＮＧ利用熱交換器３３ａで冷却された圧縮窒素ガスをさらに圧縮する循環タービン圧縮機(昇圧機)３３ｇが介装されている。この循環タービン圧縮機３３ｇは、前記膨張タービン３３ｂで駆動されるようになっており、この循環タービン圧縮機３３ｇで圧縮された圧縮窒素ガスは第１ＬＮＧ利用熱交換器３３ａで冷却された後に膨張タービン３３ｂで断熱膨張されるように構成されている。   In the nitrogen circulation cooling mechanism 3 of the air separation device according to the second embodiment of the present invention, the nitrogen circulation flow path 33 is compressed by the circulation compressor 32 on the downstream side of the circulation compressor 32, and the first LNG utilization heat exchanger. A circulating turbine compressor (a booster) 33g for further compressing the compressed nitrogen gas cooled by 33a is interposed. The circulation turbine compressor 33g is driven by the expansion turbine 33b, and the compressed nitrogen gas compressed by the circulation turbine compressor 33g is cooled by the first LNG utilization heat exchanger 33a and then the expansion turbine. It is comprised so that it may be adiabatically expanded by 33b.

本実施の形態２に係る空気分離装置によれば、窒素循環冷却機構３の窒素循環流路３３に循環タービン圧縮機３３ｇが追加されただけであるから、上記形態１に係る空気分離装置と同等の効果を得ることができる。但し、より高圧の圧縮窒素ガスを断熱膨張させることにより窒素循環流路３３の液体窒素の生産効率が向上するので、上記形態１に係る空気分離装置の窒素循環流路よりも優れている。また、循環タービン圧縮機３３ｇおよび膨張タービン３３ｂを２台以上設置することにより、窒素循環流路３３の液体窒素の生産効率をさらに向上させることができる。   According to the air separation device according to the second embodiment, since only the circulation turbine compressor 33g is added to the nitrogen circulation flow path 33 of the nitrogen circulation cooling mechanism 3, it is equivalent to the air separation device according to the first embodiment. The effect of can be obtained. However, since the production efficiency of liquid nitrogen in the nitrogen circulation channel 33 is improved by adiabatic expansion of the higher-pressure compressed nitrogen gas, it is superior to the nitrogen circulation channel of the air separation device according to the first aspect. Further, by installing two or more circulation turbine compressors 33g and expansion turbines 33b, the production efficiency of liquid nitrogen in the nitrogen circulation passage 33 can be further improved.

本発明の形態３に係る空気分離装置を、その窒素循環冷却機構の模式的系統説明図の図８を参照しながら説明する。なお、本発明の形態３に係る空気分離装置の原料空気処理部、コールドボックス、液体窒素過冷却ボックスの構成は、上記形態１に係る空気分離装置と同構成であって、窒素循環冷却機構が相違するだけであるから、同一のものに同一符号を付し、かつ同一名称を以ってその相違する点について説明する、   An air separation device according to Embodiment 3 of the present invention will be described with reference to FIG. 8 of a schematic system explanatory view of the nitrogen circulation cooling mechanism. The configuration of the raw air processing unit, the cold box, and the liquid nitrogen supercooling box of the air separation device according to the third embodiment of the present invention is the same as that of the air separation device according to the first embodiment, and the nitrogen circulation cooling mechanism is Since they are only different, the same reference numerals are assigned to the same items, and the different points are described with the same names.

本発明の形態３に係る空気分離装置の窒素循環冷却機構３では、窒素循環流路３３の循環圧縮機３２から膨張タービン３３ｂに連通する流路の間に、循環冷凍機３３ｉが介装されてなる分岐流路３３ｈが設けられている。前記循環冷凍機３３ｉは液体窒素、または冷媒を用いるもので、この循環冷凍機３３ｉで冷却した圧縮質素ガスと第１ＬＮＧ利用熱交換器３３ａで冷却した圧縮窒素ガスとを合流させた後、膨張タービン３３ｂで断熱膨張されるように構成されている   In the nitrogen circulation cooling mechanism 3 of the air separation device according to the third embodiment of the present invention, a circulation refrigerator 33i is interposed between the circulation compressor 32 of the nitrogen circulation passage 33 and the passage communicating with the expansion turbine 33b. A branch flow path 33h is provided. The circulation refrigerator 33i uses liquid nitrogen or a refrigerant. After combining the compressed elementary gas cooled by the circulation refrigerator 33i and the compressed nitrogen gas cooled by the first LNG utilization heat exchanger 33a, the expansion turbine It is configured to be adiabatically expanded at 33b

本実施の形態３に係る空気分離装置によれば、窒素循環冷却機構３の窒素循環流路３３に循環冷凍機３３ｉが介装されてなる分岐流路３３ｈが追加されただけであるから、上記形態１に係る空気分離装置と同等の効果を得ることができる。循環タービン圧縮機３３ｇを窒素循環流路３３に設置することにより、循環圧縮機３２の窒素ガスに流量を減らすことができるので、窒素循環流路３３の液体窒素の生産効率については、上記形態１に係る空気分離装置の窒素循環流路よりも優れている。   According to the air separation device according to the third embodiment, since the branch flow path 33h in which the circulation refrigerator 33i is interposed in the nitrogen circulation flow path 33 of the nitrogen circulation cooling mechanism 3 is only added. An effect equivalent to that of the air separation device according to aspect 1 can be obtained. By installing the circulation turbine compressor 33g in the nitrogen circulation channel 33, the flow rate of the nitrogen gas in the circulation compressor 32 can be reduced. This is superior to the nitrogen circulation flow path of the air separation device according to the above.

本発明の形態４に係る空気分離装置を、その窒素循環冷却機構の模式的系統説明図の図９を参照しながら説明する。なお、本発明の形態３に係る空気分離装置の原料空気処理部、コールドボックス、液体窒素過冷却ボックスの構成は、上記形態１に係る空気分離装置と同構成であって、窒素循環冷却機構が相違するだけであるから、同一のものに同一符号を付し、かつ同一名称を以ってその相違する点について説明する、   An air separation device according to Embodiment 4 of the present invention will be described with reference to FIG. 9 of a schematic system explanatory view of the nitrogen circulation cooling mechanism. The configuration of the raw air processing unit, the cold box, and the liquid nitrogen supercooling box of the air separation device according to the third embodiment of the present invention is the same as that of the air separation device according to the first embodiment, and the nitrogen circulation cooling mechanism is Since they are only different, the same reference numerals are assigned to the same items, and the different points are described with the same names.

即ち、本発明の形態４に係る空気分離装置の窒素循環流路３３は、循環圧縮機３２の吐出口から第１ＬＮＧ利用熱交換器３３ａ、膨張タービン３３ｂ、第１窒素冷熱利用熱交換器３３ｃ、第２窒素冷熱利用熱交換器３３ｄ、第２ＬＮＧ利用熱交換器３３ｅ、第１ＬＮＧ利用熱交換器３３ａを介して循環圧縮機３２の吸込口に連通している。
そして、窒素循環流路３３の循環圧縮機３２の吸込口の付近に、窒素圧縮機３１で圧縮された流路Ｃの高純度窒素ガスと、流路Ｄの高純度窒素ガスとの混合ガスが供給されるように構成されている。ＬＮＧ冷熱蓄熱流路３４と冷熱回収流路３５の経路は上記形態１の場合と同様である。 That is, the nitrogen circulation flow path 33 of the air separation device according to the fourth embodiment of the present invention includes the first LNG utilization heat exchanger 33a, the expansion turbine 33b, the first nitrogen cold heat utilization heat exchanger 33c from the discharge port of the circulation compressor 32. The second nitrogen cold heat utilization heat exchanger 33d, the second LNG utilization heat exchanger 33e, and the first LNG utilization heat exchanger 33a communicate with the suction port of the circulating compressor 32.
A mixed gas of the high-purity nitrogen gas in the flow path C compressed by the nitrogen compressor 31 and the high-purity nitrogen gas in the flow path D is near the suction port of the circulation compressor 32 in the nitrogen circulation flow path 33. It is configured to be supplied. The paths of the LNG cold heat storage flow path 34 and the cold heat recovery flow path 35 are the same as those in the first embodiment.

本発明の形態４に係る空気分離装置では、窒素循環冷却機構３に予冷器が設けられていない。また、窒素循環流路３３は循環圧縮機３２の吐出口から第１ＬＮＧ利用熱交換器３３ａ、膨張タービン３３ｂ、第１窒素冷熱利用熱交換器３３ｃ、第２窒素冷熱利用熱交換器３３ｄ、第２ＬＮＧ利用熱交換器３３ｅ、第１ＬＮＧ利用熱交換器３３ａを経由しており、この窒素循環流路３３を循環する窒素ガスは、ＬＮＧ（気液）が−５０℃以上になるまで熱交換される。循環圧縮機３２の吸込温度が常温である以外は、ＬＮＧ冷熱蓄熱流路３４と冷熱回収流路３５の経路は上記形態１の場合と同様であるから、本発明の形態４に係る空気分離装置によれば、上記形態１に係る空気分離装置と同等の効果を得ることができるが、通常の常温循環圧縮機を採用することができる。   In the air separation device according to Embodiment 4 of the present invention, the nitrogen circulation cooling mechanism 3 is not provided with a precooler. Further, the nitrogen circulation flow path 33 is connected to the first LNG utilization heat exchanger 33a, the expansion turbine 33b, the first nitrogen cold utilization heat exchanger 33c, the second nitrogen cold utilization heat exchanger 33d, and the second LNG from the discharge port of the circulation compressor 32. The nitrogen gas passing through the use heat exchanger 33e and the first LNG use heat exchanger 33a is heat-exchanged until the LNG (gas-liquid) reaches −50 ° C. or higher. Since the LNG cold heat storage channel 34 and the cold recovery channel 35 are the same as those in the first embodiment except that the suction temperature of the circulation compressor 32 is normal temperature, the air separation device according to the fourth embodiment of the present invention. According to the above, the same effect as that of the air separation device according to the first aspect can be obtained, but a normal room temperature circulation compressor can be employed.

ところで、本発明の形態４に係る窒素循環冷却機構３の冷熱回収流路３５の場合には、上記のとおり、ＬＮＧタンク３５ａからＬＮＧポンプ３５ｂを介して供給されるＬＮＧは、第２ＬＮＧ利用熱交換器３３ｅ、第１ＬＮＧ利用熱交換器３３ａを経由して冷熱蓄熱器３４ａに連通している。しかしながら、例えば第２ＬＮＧ利用熱交換器３３ｅだけ経由させて冷熱蓄熱器３４ａに連通させる構成（例えば、ＬＮＧは−１００℃になるまで熱交換される。）にすることができ、また第２ＬＮＧ利用熱交換器３３ｅの半分だけ経由させて冷熱蓄熱器３４ａに連通させる構成（例えば、ＬＮＧは−１３０℃になるまで熱交換される。）にすることもできる。   By the way, in the case of the cold recovery flow path 35 of the nitrogen circulation cooling mechanism 3 according to Embodiment 4 of the present invention, as described above, the LNG supplied from the LNG tank 35a via the LNG pump 35b is the second LNG utilization heat exchange. It communicates with the cold heat regenerator 34a via the heat exchanger 33e and the first LNG utilization heat exchanger 33a. However, for example, the configuration can be such that only the second LNG utilization heat exchanger 33e is communicated with the cold energy regenerator 34a (for example, LNG is heat exchanged until it reaches −100 ° C.), and the second LNG utilization heat is used. It is also possible to adopt a configuration in which only half of the exchanger 33e is communicated with the cold heat storage device 34a (for example, LNG is heat exchanged until it reaches −130 ° C.).

なお、以上の形態においては、何れもＬＮＧタンクから供給できるＬＮＧの供給量が多いときにはＬＮＧの冷熱を蓄熱し、ＬＮＧタンクから供給できるＬＮＧの供給量が少ないときには蓄熱した冷熱を回収して運転を継続するという、本発明の技術的思想を空気分離装置に適用した場合を説明した。しかしながら、本発明の技術的思想を、空気分離装置に対してだけでなく、空気分離系統を持たない寒冷発生装置の循環系統に対しても適用することができる。   In any of the above forms, when the supply amount of LNG that can be supplied from the LNG tank is large, the cold energy of LNG is stored, and when the supply amount of LNG that can be supplied from the LNG tank is small, the stored cold heat is recovered. The case where the technical idea of the present invention, which is continued, is applied to an air separation device has been described. However, the technical idea of the present invention can be applied not only to an air separation device but also to a circulation system of a cold generator having no air separation system.

本発明の形態１に係る空気分離装置の模式的系統図である。It is a typical systematic diagram of the air separation apparatus which concerns on form 1 of this invention. 本発明の形態１に係る空気分離装置の原料空気処理部の模式的系統説明図である。It is typical system explanatory drawing of the raw material air processing part of the air separation apparatus which concerns on form 1 of this invention. 本発明の形態１に係る空気分離装置のコールドボックスと液体窒素過冷却部のコールドボックスとの模式的系統説明図である。It is typical system explanatory drawing of the cold box of the air separation apparatus which concerns on form 1 of this invention, and the cold box of a liquid nitrogen supercooling part. 本発明の形態１に係る空気分離装置の窒素循環冷却機構の模式的系統説明図である。It is typical system explanatory drawing of the nitrogen circulation cooling mechanism of the air separation apparatus which concerns on form 1 of this invention. 本発明の形態１に係る変形例１に関し、窒素循環冷却機構の模式的部分系統説明図である。It is typical partial system explanatory drawing of a nitrogen circulation cooling mechanism regarding the modification 1 which concerns on the form 1 of this invention. 本発明の形態１に係る変形例２に関し、窒素循環冷却機構の模式的部分系統説明図である。It is typical partial system explanatory drawing of a nitrogen circulation cooling mechanism regarding the modification 2 which concerns on the form 1 of this invention. 本発明の形態２に係る空気分離装置の窒素循環冷却機構の模式的系統説明図である。It is typical system explanatory drawing of the nitrogen circulation cooling mechanism of the air separation apparatus which concerns on form 2 of this invention. 本発明の形態３に係る空気分離装置の窒素循環冷却機構の模式的系統説明図である。It is typical system explanatory drawing of the nitrogen circulation cooling mechanism of the air separation apparatus which concerns on form 3 of this invention. 本発明の形態４に係る空気分離装置の窒素循環冷却機構の模式的系統説明図である。It is typical system explanatory drawing of the nitrogen circulation cooling mechanism of the air separation apparatus which concerns on form 4 of this invention. 従来例に係る空気分離装置の系統図である。It is a systematic diagram of the air separation apparatus which concerns on a prior art example.

符号の説明Explanation of symbols

Ａ，Ｂ，Ｃ，Ｄ，Ｅ，Ｆ…流路
１…原料空気処理部，１１…吸込フィルタ，１２…空気圧縮機，１３…クーラ、１４…ＭＳ吸着器，１５…再生電気ヒータ，１６…サイレンサ
２…コールドボックス，２１…主熱交換器，２２…低圧精留塔，２３…高圧精留塔，２４…過冷却器，２５…酸素リッチな液体空気，２６…主凝縮器
３…窒素循環冷却機構，３１…窒素圧縮機，３２…循環圧縮機，３３…窒素循環流路，３３ａ…第１ＬＮＧ利用熱交換器，３３ｂ…膨張タービン，３３ｃ…第１窒素冷熱利用熱交換器，３３ｄ…第２窒素冷熱利用熱交換器，３３ｅ…第２ＬＮＧ利用熱交換器，３３ｆ…予冷器，３３ｇ…循環タービン圧縮機，３３ｈ…分岐流路，３３ｉ…循環冷凍機，３４…ＬＮＧ冷熱蓄熱流路，３４ａ…冷熱蓄熱器，３５…冷熱回収流路，３５ａ…ＬＮＧタンク，３５ｂ…ＬＮＧポンプ，３６…ＮＧ排出流路，３７…ＬＮＧ加温器，３８ａ…ＬＮＧ供給元タンク，３８ｂ…ＬＮＧ供給元ポンプ
４…液体窒素過冷却ボックス，４１…気液分離器，４２…液体窒素過冷却器，４３…液体窒素流路，４４…流量制御弁，４５…液体窒素温度検出センサ、４６…低温の窒素ガス，４７…液体窒素 A, B, C, D, E, F ... flow path 1 ... raw material air processing unit, 11 ... suction filter, 12 ... air compressor, 13 ... cooler, 14 ... MS adsorber, 15 ... regenerative electric heater, 16 ... Silencer 2 ... Cold box, 21 ... Main heat exchanger, 22 ... Low pressure rectification column, 23 ... High pressure rectification column, 24 ... Supercooler, 25 ... Oxygen-rich liquid air, 26 ... Main condenser 3 ... Nitrogen circulation Cooling mechanism, 31 ... nitrogen compressor, 32 ... circulation compressor, 33 ... nitrogen circulation flow path, 33a ... first LNG utilization heat exchanger, 33b ... expansion turbine, 33c ... first nitrogen cold utilization heat exchanger, 33d ... first 2 Nitrogen cold heat exchanger, 33e ... 2nd LNG heat exchanger, 33f ... Precooler, 33g ... Circulating turbine compressor, 33h ... Branch channel, 33i ... Circulating refrigerator, 34 ... LNG cold heat storage channel, 34a ... Cool storage, 35 ... Cool recovery Path, 35a ... LNG tank, 35b ... LNG pump, 36 ... NG discharge flow path, 37 ... LNG heater, 38a ... LNG supply source tank, 38b ... LNG supply source pump 4 ... liquid nitrogen supercooling box, 41 ... air Liquid separator, 42 ... Liquid nitrogen supercooler, 43 ... Liquid nitrogen flow path, 44 ... Flow rate control valve, 45 ... Liquid nitrogen temperature detection sensor, 46 ... Low temperature nitrogen gas, 47 ... Liquid nitrogen

Claims (2)

液化天然ガスタンクから十分な量の液化天然ガスを供給することができるときには、液化天然ガスの冷熱による圧縮窒素ガスの冷却および冷熱蓄熱器への前記液化天然ガスの冷熱の蓄熱をし、蓄熱後の液化天然ガスは液化天然ガス加温器で気化させて天然ガスを製造する一方、液化天然ガスタンクから供給できる液化天然ガスの供給量が少ないときには、液化天然ガスタンクから液化天然ガスポンプを経て供給した液化天然ガスの冷熱で圧縮窒素ガスを冷却して自らは昇温して１部または全てがガス化するこの液化天然ガスまたは天然ガスを、液化天然ガスタンクから液化天然ガスポンプを経て供給した液化天然ガスに合流させて液化天然ガスの２相流とした後に、前記冷熱蓄熱器に流入させて２相流の液化天然ガスを液化することで冷熱を回収すると共に、冷熱回収後の液化天然ガスを前記液化天然ガスタンクに戻すことを特徴とする空気分離装置の運転方法。 When it is possible to supply a sufficient amount of liquefied natural gas from the liquefied natural gas tank, said the cold heat of the heat storage of liquefied natural gas to the cooling and cold heat accumulator compressed nitrogen gas by cold of liquefied natural gas, after the heat storage While liquefied natural gas is vaporized with a liquefied natural gas warmer to produce natural gas, when the amount of liquefied natural gas that can be supplied from the liquefied natural gas tank is small, liquefied natural gas supplied from the liquefied natural gas tank via the liquefied natural gas pump is used. The compressed nitrogen gas is cooled with the cold heat of the gas, and the liquefied natural gas or natural gas, one part of which is gasified by heating itself, joins the liquefied natural gas supplied from the liquefied natural gas tank via the liquefied natural gas pump. The liquefied natural gas is converted into a two-phase flow, and then flows into the cold heat accumulator to liquefy the two-phase liquefied natural gas. While yield, a method operation of the air separation unit and returning the liquefied natural gas after cold recovery in the liquefied natural gas tank. 前記冷熱回収後の液化天然ガスを液化天然ガスタンクに戻す前に、窒素循環冷却機構で発生する寒冷を利用して冷却することを特徴とする請求項１に記載の空気分離装置の運転方法。 2. The method of operating an air separation device according to claim 1 , wherein the liquefied natural gas after the cold heat recovery is cooled using cold generated by a nitrogen circulation cooling mechanism before being returned to the liquefied natural gas tank.
JP2003370739A 2003-10-30 2003-10-30 Operation method of air separation device Expired - Lifetime JP4276520B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2003370739A JP4276520B2 (en) 2003-10-30 2003-10-30 Operation method of air separation device
TW093131546A TWI270644B (en) 2003-10-30 2004-10-18 Air separator and operating method thereof
KR1020040086496A KR100618735B1 (en) 2003-10-30 2004-10-28 Air separator and operation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2003370739A JP4276520B2 (en) 2003-10-30 2003-10-30 Operation method of air separation device

Publications (2)

Publication Number Publication Date
JP2005134036A JP2005134036A (en) 2005-05-26
JP4276520B2 true JP4276520B2 (en) 2009-06-10

Family

ID=34647656

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2003370739A Expired - Lifetime JP4276520B2 (en) 2003-10-30 2003-10-30 Operation method of air separation device

Country Status (3)

Country Link
JP (1) JP4276520B2 (en)
KR (1) KR100618735B1 (en)
TW (1) TWI270644B (en)

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7552599B2 (en) 2006-04-05 2009-06-30 Air Products And Chemicals, Inc. Air separation process utilizing refrigeration extracted from LNG for production of liquid oxygen
US8820096B2 (en) 2007-02-12 2014-09-02 Daewoo Shipbuilding & Marine Engineering Co., Ltd. LNG tank and operation of the same
US20090199591A1 (en) 2008-02-11 2009-08-13 Daewoo Shipbuilding & Marine Engineering Co., Ltd. Liquefied natural gas with butane and method of storing and processing the same
KR20090107805A (en) 2008-04-10 2009-10-14 대우조선해양 주식회사 Method and system for reducing heating value of natural gas
CN101839612B (en) * 2010-04-06 2012-05-02 浙江大学 Backward flow type air separation system and method based on cold energy utilization of LNG (Liquefied Natural Gas) satellite station
KR101051306B1 (en) * 2010-10-05 2011-07-22 한국기계연구원 Compressed air energy storage generation system
CA2840723C (en) * 2011-08-09 2019-10-01 Exxonmobil Upstream Research Company Natural gas liquefaction process
CN102705705A (en) * 2012-05-31 2012-10-03 天津华迈燃气装备股份有限公司 Phase-change-free liquefied natural gas (LNG) cold energy utilization device for refrigerator
CN104019628B (en) * 2014-05-14 2016-04-13 中国海洋石油总公司 Make the method that space division system runs continuously during the supply discontinuity of LNG cold energy
CN105466154B (en) * 2015-12-21 2017-12-15 七台河宝泰隆煤化工股份有限公司 A kind of space division technique method
EP3682177A1 (en) * 2017-09-14 2020-07-22 Chart Energy & Chemicals, Inc. Mixed refrigerant condenser outlet manifold separator
CN110319651A (en) * 2018-03-29 2019-10-11 舒伟 A kind of natural gas gathering system and collection transportation method based on cold energy circulation
CN109140903B (en) * 2018-08-24 2024-01-09 邢仁钊 Air separation system and air separation method utilizing cold energy of liquefied natural gas
JP7379763B2 (en) * 2019-07-25 2023-11-15 レール・リキード－ソシエテ・アノニム・プール・レテュード・エ・レクスプロワタシオン・デ・プロセデ・ジョルジュ・クロード Gas liquefaction method and gas liquefaction device
CN114992505A (en) * 2022-05-05 2022-09-02 赵启轩 Intelligent liquid nitrogen tank

Also Published As

Publication number Publication date
KR20050041916A (en) 2005-05-04
TW200517628A (en) 2005-06-01
KR100618735B1 (en) 2006-08-31
JP2005134036A (en) 2005-05-26
TWI270644B (en) 2007-01-11

Similar Documents

Publication Publication Date Title
JP3947565B2 (en) Method and apparatus for variable generation of pressurized product gas
JP4276520B2 (en) Operation method of air separation device
JP3086857B2 (en) Method for generating cold, cooling cycle using this method, and air rectification method and apparatus using this method
CN109690215A (en) Industrial gasses place produces integrated with liquid hydrogen
KR100192874B1 (en) Air separation
WO2000052403A1 (en) Natural gas letdown liquefaction system
JP5547283B2 (en) Pressurized product generating method and generating apparatus
WO2000057118A1 (en) Industrial gas pipeline letdown liquefaction system
US9360250B2 (en) Process and apparatus for the separation of air by cryogenic distillation
EP3719427A1 (en) Cryogenic distillation method and apparatus for producing pressurized air by means of expander booster in linkage with nitrogen expander for braking
JPH11351738A (en) Method and system for producing high purity oxygen
CN106595221A (en) Oxygen production system and oxygen production method
CN108700373A (en) System and method for rare gas recycling
CN105378411B (en) Produce method, the air separation plant, the method and apparatus produced electricl energy of at least one air products
JP2007147113A (en) Nitrogen manufacturing method and device
JP3737611B2 (en) Method and apparatus for producing low purity oxygen
MX2010011008A (en) Method and device for generating liquid nitrogen from low temperature air separation.
EP1726900A1 (en) Process and apparatus for the separation of air by cryogenic distillation
JP2005221199A (en) Air separation device
JP2001141359A (en) Air separator
US5711166A (en) Air separation method and apparatus
KR100694376B1 (en) Sub-zero air separation apparatus and an operating method of the same
JP4408211B2 (en) Pressure adjusting device for liquefied natural gas tank and pressure adjusting method thereof
JP2005090915A (en) Air separator and air separating method
JP4202971B2 (en) Nitrogen production method and apparatus

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20050922

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20080122

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20080219

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20080421

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20080805

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20081001

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20090303

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20090306

R150 Certificate of patent or registration of utility model

Ref document number: 4276520

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120313

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120313

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130313

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140313

Year of fee payment: 5

S531 Written request for registration of change of domicile

Free format text: JAPANESE INTERMEDIATE CODE: R313531

R360 Written notification for declining of transfer of rights

Free format text: JAPANESE INTERMEDIATE CODE: R360

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313113

R360 Written notification for declining of transfer of rights

Free format text: JAPANESE INTERMEDIATE CODE: R360

R371 Transfer withdrawn

Free format text: JAPANESE INTERMEDIATE CODE: R371

S531 Written request for registration of change of domicile

Free format text: JAPANESE INTERMEDIATE CODE: R313531

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313113

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313111

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

EXPY Cancellation because of completion of term